Annual/Termination Reports:

[03/02/2015] [01/15/2016] [02/21/2017] [02/04/2018] [03/06/2019]

Report Information

Participants

Andrews, Shannon - Oregon State University; Aramak, Surachet - Washington State University; Berli, Markus - Desert Research Institute; Flury, Markus, Washington State University; Ghezzehei, Teamrat - University California, Merced; Heinse, Robert - University of Idaho; Jin, Yan - University of Delaware; Kelleners, Thijs - University of Wyoming; Knighton, Ray - USDA; Liang, Jing - University California, Riverside; Maradzadeh, Mostafa - University California, Riverside; Nieber, John - University of Minnesota; Patrignani, Andres - Oklahoma State University; Shillito, Rose - Desert Research Institute; Shukla, Manoj - New Mexico State University; Simunek, Jiri - University California, Riverside; Skaggs, Todd - USDA-ARS; Sparrow, Stephen - University of Alaska Fairbanks; Stoy, Paul - Montana State University; Tuller, Markus - University of Arizona; Wendroth, Ole - University of Kentucky; Young, Michael - University of Texas.

Brief Summary of Minutes

2015 Annual Meeting of the W-3188 Multi-State Research Project: Soil, Water, and Environmental Physics across Scales January 3-5, 2015, Desert Research Institute, Las Vegas, NV

January 3, 2015

Robert Heinse was Chair and Manoj Shukla was secretary. Chair brought the house to order at 1 PM.

Ray Knighton, USDA spoke about the new project W3188. He told that depending upon an Institution, separate project proposals are required by experimental stations. ES Directors (not the USDA) normally decide on all the issues including how many proposals or persons will be involved.

Regarding acknowledging NIFA in publications, use the lines provided by NIFA (award number that is provided to each Institute’s ES). In the report system, there is a six digit number also known as report identifier can be used.
In 2014 a new water program is offered by AFRI. Plan in 2015 is to continue the water program as well as cap and standard grant programs. CAP will be good to writing a multistate type of project.

Stephen Sparrow, Administrate Advisor, told that W3188 approved for next five years (2019). There are 34 participants listed on the project and are from 18 states.

Michael Young, University of Texas at Austin talked about the permafrost soils in Alaska. High resolution C inventory and dynamics in permafrost soils, north slope Alaska. Methane emissions and C fate and transport are important in Arctic tundra.

Paul Stoy, Montana State University talked about the underappreciated role of soil physics in surface atmosphere exchange.

Yan Jin, University of Delaware, talked about colloid mobilization and biogeochemical recycling of organic matter, nitrogen and phosphorus in wetlands.

Todd Skaggs, USDA-ARS, Salinity Lab showed the analytical steady state solutions for water-limited cropping systems using saline irrigation water.
Raymond Anderson, USDA-ARS, Water Management, talked about the constraining consumptive water use and water use efficiency in a production peach orchard in California’s San Joaquin valley.

January 4, 2015

Markus Flurry, Washington State University talked about colloid fate and transport in unsaturated zone.

Surachet Aramrak, Washington State University presented colloid mobilization and transport during capillary fringe fluctuation.

Ole Wendroth, University of Kentucky, discussed temporal dynamics and stability of spatial processes of soil water status is important for efficient soil water monitoring and water and solute modeling.

Jiri Simunek, University of California, Riverside talked about Hydrus and PHREEQC and the recent updates made on HYDRUS.

Mostafa Moradzadeh, University of California, Riverside (PhD student) presented optimal estimation of van Genuchten parameters for preferential water flow conditions in soil.

Jing Liang, University of California, Riverside (PhD student), presented a duel permeability model to describe overland flow and microbial transport.

Alex Furman, Technion Israel Institute of Technology (not from the group), spoke about the microbial effects on the hydraulic properties of unsaturated soils.

Andres Patrignani (PhD student of Tyson Ochsner), Oklahoma State University presented soil water dynamics under different crops.

Shannon Andrews, Oregon State University (PhD student) (Maria is the soil physicist) presented results on water repellency investigations using infrared spectroscopy.

Rose Shillito and Markus Berli, Desert Research Institute presented a talk on where does water go in desert soils?

Alex Furman, Technion Israel Institute of Technology (not from the group) talked about the elemental signature of contaminated soil.

John Nieber, University of Minnesota, assessed the total phosphorus load for the watershed and quantified each component.

Business

Next meeting: motion was moved for Las Vegas and was unanimously approved.
Dates of next meetings were approved as: Sunday January 3rd- January 5th, 2016.
Chair: Manoj Shukla, New Mexico State University took over as Chair.
New secretary: Teamrat Ghezzehei, University of California, Merced is elected as new Secretary

Next year: theme based presentation, using the project objectives is proposed.
January 5th, 2015

Markus Tuller, The University of Arizona, presented results on soil physicochemical properties derived from water vapor sorption.
Scott Jones, Utah State University talked about ET assessment in experimental forest.

Wenyi (Postdoc) Utah State Univ., presented data on sensor development and calibration were performed in soils.

Morteza (Postdoc) Utah State Univ. presented similar media concept of miller and miller (1956) can be used for similar soils.

Teamrat Ghezzehei, University of California, Merced, showed that the soil water potential decreases influence the C emissions from soil.

Manoj Shukla, NMSU-ACES presented on irrigation water efficiency using partial rot zone drying.

Thijs Kelleners, University of Wyoming talked about coupled soil water flow and transport and other processes related to the model development.

Accomplishments

Short-term outcomes<br /> <br /> Participants from USDA-ARS Conservation & Production Research Laboratory, Bushland, Texas determined that the cosmic ray soil moisture observing system (COSMOS) was not useful for irrigation management by comparing it with an in situ sensor network (EM and neutron probe sensors) and a large weighing lysimeter. AquaCrop model has serious problems with the soil evaporation algorithms and the discretization for soil water flux calculations that result in the model grossly overestimating early season soil water evaporative losses, reducing the water available for plant growth over time. (Evett, Schwartz)<br /> Washington State University showed that the capillary fringe is an important part of the vadose zone, it is the region where the groundwater meets the unsaturated zone. The action of the moving air-water interfaces in the capillary fringe can scour colloidal contaminants, zone, thereby making these contaminants more mobile. It is important to understand which topographic features influence the distribution of exposed mineral soil following wildfire, with simple GIS tools. To reduce the pollution of surface water bodies, techniques, including rain gardens and bioretention facilities, have been developed. (Flury, Wu)<br /> <br /> Oregon State University improved method to determine contact angles (Dragila).<br /> <br /> Participants from University of Minnesota developed (Objective 1) a whole watershed balance of phosphorus in a 377 km2 watershed in southcentral Minnesota has shown that phosphorus is used very efficiently and for the year of study the P leaving the watershed in the form of agricultural products was 1.7 times the amount entering. They also worked on groundwater contributions to Minnehaha Creek. As part of Objective 3, estimation of soil effective saturated hydraulic conductivity using the Modified Philip-Dunne method was found to be predicted within 65% of the true value for layered soil and 30% for a soil containing a single vertical macropore. (Nieber)<br /> <br /> Participants from Montana State University measured the surface-atmosphere exchange of water, energy, and CO2 using the eddy covariance system in the Judith Basin, MT. They contributed on the role of forest management on climate-relevant exchanges of energy and carbon dioxide. They also synthesized radiometric and eddy covariance data and model output and performed analyses for multiple manuscripts on surface temperature and evapotranspiration. (Stoy)<br /> Participants from U.S. Salinity Laboratory, USDA-ARS, Riverside did the critical review of existing microbial transport and survival models, and assessment of their ability to simulate E.coli species under a variety of environmentally relevant scenarios. They developed new mathematical models to manage irrigation under water-limited conditions. Column studies investigated long-term retention behavior of nanoparticles under different solution chemistry and water velocity and transport of E coli. (Skaggs, Bradford, Anderson)<br /> <br /> Participants from University of Delaware developed sampling and analysis protocols for quantification of colloids in different size fractions. They measured total organic carbon (TOC) content in different size colloid fractions. Research also incorporated surface roughness into a triangular pore space model and significantly improved predictions of unsaturated hydraulic conductivity over the entire range of matric potentials compared with the van Genucthen-Mualem model while keeping the same number of parameters. (Jin)<br /> Participants from Utah State University continued to collect a sixth year of climate, snow and soil data across 15 monitoring towers were collected at the T.W. Daniel Experimental Forest (TWDEF) in Northern Utah. Data are available at http://danielforest.usu.edu. (Jones)<br /> <br /> Participants from New Mexico State University developed fracturing technologies, examined chemical composition of oil/gas waste water (i.e., produced water), and developed oxidant complexation and delivery technologies (Carrol). Improved irrigation strategies were developed for irrigating chile with limited water and helophytes with RO concentrate. Suitability of popular desert restoration sequence was evaluated with Northwest University, China. (Shukla, Qi)<br /> <br /> Participants from University of Arizona developed and tested a Fully Automated Microlysimeter for measurement of soil evaporation. They tested a Novel Penta-Needle Heat Pulse Probe Array. 3D multiphase segmentation capabilities for X-Ray CT data and fully-automated multiplexed surface chamber system were improved. A new 2-stage method was developed to predict the soil water characteristic from saturation to oven-dryness. Novel methods were developed to predict soil specific surface area (SSA) and clay content from water vapor sorption isotherms in collaboration with Aarhus and Aalborg Universities in Denmark (Markus Tuller).<br /> <br /> Participants from University of Arizona developed the framework for three educational modules on reclamation, environmental. Impacts of mining, and socio-­?cultural impacts of mining were studied. Partnerships were developed with tribal college on the Navajo Nation to develop educational modules on uranium and impacts of uranium mining. A water balance model was developed for the Pyramid Lake Paiute Tribe and developed hypothetical scenarios using climate change projects for climate adaptation planning. (Karletta Chief)<br /> <br /> Participants from University of Arizona developed a Lattice Boltzmann model (LB) for simulating single-phase flow in large volumes of sparse poposity (macro-pores), added equations of state to LB model to simulate physical pressure, temperature and density of environmental air-solid-water systems (soils) and geological media (geological CO2 dequestration of super-critical CO2), and updated the Rosetta model for estimation of soil hydraulic properties. (M Schaap)<br /> <br /> Participants from Virginia Tech developed a new parsimonious framework to model soil-water interactions in shrink-swell clay soils. VT developed novel infiltration solutions to analyze soil physical properties from single ring infiltration sources in collaboration with Oregon State University and American University of Beirut. (R Stewart)<br /> <br /> Participants from North Dakota State University investigated soil water retention and conductivities for smectite clay soils subjected to various levels of salinity and sodicity. Brine spills from oil and gas development were surveyed. New equations were developed for relating EC among the three methodologies. A comprehensive model was used to simulate the coupled sorption and transformation of asulfate estrogen conjugate, 17 beta-estradiol-17-sulfate (E2-17S), in various soil-water systems (non-sterile/sterile; topsoil/subsoil). (Daigh, Casey)<br /> <br /> Participants from University of Wyoming continued to improve and test a 1-D vertical model for calculating water, heat, and carbon fluxes in the soil-plant-atmosphere system. They used USDA-SCAN soil moisture data along a latitudinal gradient between Montana and Texas to study drought conditions in shortgrass prairie soils. UW parameterized the GEOtop integrated model for the calculation of water flow in snow-dominated complex mountainous terrain as part of the NSF-EPSCOR project on the Wyoming Center for Environmental Hydrology and Geophysics in the Medicine Bow National Forest. (Thijs Kelleners)<br /> <br /> Participants from University of California Riverside improved HYDRUS model by developing specialized modules for more complex applications. UCR adapted the HP models so that we can dynamically update various physical properties, such as porosity, soil hydraulic properties, tortuosity, dispersion, and heat conductivity and dispersivity in response to changing chemical properties. They reviewed approaches to model the microorganism transport and survival in the subsurface and release of E. coli D21g is affected by transients in water content. (Šim?nek)<br /> <br /> Participants from University of California Riverside continued to develop an efficient integrated Bayesian approach for optimal sampling location design in groundwater contaminant source identification, and also worked on determining the fate and transport of two natural pesticides from plant extracts in soils.<br /> Participants from Texas A&M University developed a number of spatio-temporal scaling algorithms that may be applied for various agricultural, hydrologic, soil-vegetation-atmosphere-transfer, and contaminant fate and transport modeling and remediation strategies. They organized of a symposium on “Arid Zone Hydrology under Climate Change Scenarios for the 21st Century” during February 27-28, 2014 at Texas A&M University. (B Mohanty)<br /> <br /> Participants from University of Nevada, Reno has submitted a number of proposals that will include activities related to the working group. (Verburg)<br /> Participants from University of Kentucky, Lexington worked on subsurface irrigation through tile drains in heavy clay soils. Other project involved identification of the right “dirt” for the Keeneland racetrack, internal drainage experiment with implications of a “well-drained” soil, and water management in stony soils – handling of soil hydraulic properties in the presence of stones (cooperation with University of Navarra). (Wendroth).<br /> <br /> Participants from University of California, Davis worked on Innovative state-of-the-art wireless sensor networks and tested and deployed them to monitor soil moisture and soil water potential real-time and 24/7, across various cropped fields in the San Joaquin Valley, with specific application to tree crops. Development of alternative and robust heat pulse probe design was carried out towards a soil-in dependent soil moisture measurement technique.<br /> Participants from Iowa State University developed an improved thermo-TDR sensor, quantified the magnitude of subsurface soil water evaporation, developed continuum percolation theory further, determined the impact of transient soil porosity on soil gas diffusivity, and developed an improved algorithm for analyzing waveforms of short TDR probes. Developed an empirical model to estimate soil thermal conductivity. (R. Horton, R. Ewing)<br /> Participants from University of Idaho continued to improve and test a method to combine spatial measurements of soil heterogeneity with spatiotemporal variability in soil moisture. (Heinse)<br /> <br /> Outputs<br /> <br /> USDA-ARS Research Laboratory, Bushland, TX patented WOAT TDR sensor system. Research results were disseminated through 4 peer-reviewed journal articles and 2 proceedings articles, 18 conference presentations, 4 of them international and 12 of them invited.<br /> <br /> Washington State University published our research results in 4 peer-reviewed journal publications, one thesis and presented research results in national and international conferences.<br /> <br /> Oregon State University published one peer-reviewed journal article and four presentations.<br /> <br /> University of Minnesota published two refereed journal articles based on the outcomes of the project activities. Three project reports have been completed. Five abstracts were published, five conference presentations (oral or poster) were made, and one article was published.<br /> <br /> Montana State University published 8 peer-reviewed journal articles, collaborated with different universities on various projects, and gave two conference presentations.<br /> <br /> US Salinity Lab Riverside published 13 refereed journal publications, conference proceedings, and presentations at national and international meetings. Collaborative research is ongoing with researchers in Australia, Taiwan, and the United Kingdom.<br /> <br /> University of Delaware published research results in collaboration with various involved groups through 3 peer-refereed journal publications (3 more in review) and 6 conference contributions.<br /> <br /> Utah State University published 4 peer-reviewed journal articles and 8 conference presentations.<br /> <br /> New Mexico State University disseminated research results were in collaboration with various groups through 12 peer-refereed international journal publications, and 18 conference contributions. One text-book on Soil Physics an Introduction was also published in 2014. One YouTube video on use of RO concentrate for agriculture was produced and 3 newspaper articles.<br /> <br /> University of Arizona disseminated research results in collaboration with various groups through 13 peer-refereed journal publications, 1 book chapter, and 22 conference contributions. <br /> <br /> University of Arizona research results and extension programs were disseminated through 5 submitted conference presentations, 2 invited seminars, 8 guest lectures, 4 seminars/webinars, 9 extension presentations, 2 refereed journal publications, 1 extension publication, 5 technical reports, 1 newsletter, and 2 websites.<br /> <br /> University of Arizona published two peer-reviewed papers and 6 conference presentations.<br /> <br /> Virginia Tech research results were presented through 6 peer-refereed international journal publications, 2 conference presentations, 1 seminar presentation, and 1 conference poster.<br /> <br /> North Dakota State University had 4 presentations at conferences, 11 publications in peer-reviewed journals, 1 thesis, and 1 video.<br /> <br /> University of Wyoming’s one peer-reviewed journal paper was accepted on the disturbance of salt-affected soils in Wyoming. Three conference contributions were submitted.<br /> <br /> University of California Riverside disseminated research findings were via 22 refereed journal publications, 2 conference proceedings, and 26 number of presentations at national and international meetings. HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects.<br /> <br /> University of California Riverside disseminated research findings were via 12 refereed journal publications, book chapter, and 7 presentations at national and international meetings.<br /> <br /> Texas A&M University published 2 peer-reviewed journal articles and 17 presentations and abstract. A new integrated scaling/modeling platform was developed.<br /> <br /> University of Nevada, Reno submitted several proposals have been to federal agencies including the USDA, DOE and NSF focusing on interactions between hydrology and biogeochemical processes in managed and unmanaged soils in (semi)arid regions.<br /> <br /> University of Kentucky disseminated research results in collaboration with various involved groups through dissertations, short courses, and 7 conference presentations.<br /> <br /> University of California, Davis development of a field protocol to assess soil nitrate leaching at the field-scale, including the design of a new tensiometer allowing water leaching measurements at large depths below the rooting zone. Model sensitivity of drip irrigation management scenarios to assist farmers and managers as they adoption sustainable and efficient irrigation systems. Develop simple and reliable soil water sensing systems to accurately quantify soil water balance and other hydrological processes. Several presentations were also made in conferences.<br /> <br /> Iowa State University disseminated research results in collaboration with various involved groups through 20 peer-refereed international journal publications. <br /> <br /> University of Idaho published two peer-reviewed journal papers in 2014. One on the morphology of lateral preferential pathways in forest soils, the other on land-use change impacts on soil hydraulic properties. Eight conference contributions were submitted.<br /> <br /> Activities<br /> <br /> USDA-ARS Conservation & Production Research Laboratory, Bushland, TX developed and calibrated a new model of spatially varying infiltration, overland flow and soil water flux that includes a cotton growth module and applied it to situations of center pivot and lateral move sprinkler irrigation. Two prototypes were developed and tested in an effort to reduce manufacturing costs and improve durability. Results were reported and a demonstration was conducted to the IAEA and international research partners in Beijing, China and Vienna, Austria. They also continued characterization and testing of the cosmic ray soil moisture observing system (COSMOS) unit at Bushland.<br /> <br /> Washington State University studied the effects of capillary fringe fluctuations on colloid mobilization and transport. Our previous microscopic and theoretical investigations have shown that moving air-water interfaces can effectively remove colloids attached to a stationary surface when a three-phase contact line forms where strong capillary forces act between the air-water interface and the colloidal particle. We investigated the relationship between select topographic features and the distribution of exposed mineral soil following wildfire in forested watersheds. The spatial distribution of fire effects along hill slopes was assessed using geographic information system (GIS), and a regression relationship was derived. We characterized the transport and fate of urban stormwater pollutants.<br /> <br /> Oregon State University have used Fourier Transformed Infrared (FTIR) spectroscopy to investigate the changes in molecular orientation of various types of organic matter through wetting and drying cycles. measured the effect of polymeric-model substances (starch based polymers) on the moisture retention curve, and measured the effect of initial soil moisture on dynamic hydraulic diffusivity using transient capillary rise data.<br /> <br /> University of Minnesota for Objective 1 monitored riparian zone flow processes in two watersheds in Minnesota to quantify the sources of water contributing to erosion of streambanks in those watersheds. Used stable isotopes of oxygen and hydrogen to derive the groundwater contribution to Minnehaha Creek, a stream in the Twin Cities Metro Area of Minnesota, monitored three stormwater infiltration practice sites, and total Petroleum Hydrocarbon and conducted analysis of soil moisture, soil temperature, and flow data. As part of Objective 3, we performed assessments of the quantity of near-channel erosion in three watersheds representing different various regions of Minnesota.<br /> Montana State University. in a collaboration with colleagues from Ohio State University and elsewhere, explored the ability of ecosystem models to replicate the observed hydrodynamic drawdown of ET observed across multiple eddy covariance sites across North America. They determined that the effect of wind speed on forest transpiration is dominated by the reduction of vapor pressure deficit and corresponding decreases in stomatal conductance rather than a reduction of aerodynamic resistance to water flux. The role of plant functional type and climate on ecosystem radiative entropy production was quantified and carbon dioxide and water flux observations from adjacent deciduous and evergreen forests were synthesized.<br /> <br /> U.S. Salinity Laboratory, USDA-ARS as part of Objective 1 continued the development of new technologies for improved modeling of coupled overland and subsurface flow and transport. As part of Objective 3 they continued work on the development of new modeling tools. Research activities in 2014 included investigations of different possible model representations of processes (model complexity) affecting crop growth and soil salinization at spatial and temporal scales relevant to managers and regulators.<br /> <br /> University of Delaware measured mobile colloid concentrations and associated OC content for samples from different aquatic ecosystems, including agricultural, forestry, estuarine and wetlands. They developed a roughness-triangular-pore-space model (R-TPSM), in which soil pores were represented by a series of triangular tubes and the inside walls of the tubes were assumed as rough. In a collaborative project, they examined the impacts of citrate-coated silver nanoparticles (c-AgNPs) on two species of bacteria.<br /> <br /> Utah State University continued to collect data and quality control and management of climate towers. Work continued on Penta-needle Heat Pulse Probe and evaporation and transpiration processes at the TW Daniel Experimental Forest.<br /> <br /> New Mexico State University continued to work on a vadose-zone gas-phase contaminant characterization technology, developed monitoring capabilities to allow reservoir stimulation for renewable energy production, developing in situ chemical oxidation for 1,4-dioxane groundwater plume remediation by enhancing the solubility, stability, and transportability of strong oxidants, and developing methods and data needed for implementing environmentally sound strategies and beneficial use of produced waters. We are also working on utilizing RO concentrate to grow helophytes, establish threshold salinity levels for chile peppers and irrigation management. In collaboration with Northwest University, China, we tested the popular “grass-shrub-tree” restoration sequence.<br /> <br /> University of Arizona further improved 3D multiphase segmentation capabilities for X-Ray CT data. In collaboration with Utah State University, UA developed and improved a fully-automated multiplexed surface chamber system (12-chamber unit) to measure greenhouse and regulated gas emissions from animal feeding operations with Fourier transform infrared spectroscopy. In collaboration with Aarhus and Aalborg Universities, UA tried to establish links between biodiversity loss and soil ecosystem functions. Another collaborative project with Aarhus and Aalborg Universities, UA developed a novel 2-stage approach to predict the soil water characteristic from saturation to oven-dryness from the particle size distribution.<br /> <br /> University of Arizona worked on vulnerability of tribes in the Southwest to climate change. Project ‘incorporating climate information and stakeholder engagement in groundwater management” developed a novel method to engage stakeholders and to apply and refine a decision tool, which can be applied to tribal stakeholders. Project on water resource management is credited for the development of educational material for the Navajo Nation on climate change education, where language is a primary barrier to understanding hydrology and climate change. <br /> <br /> University of Arizona worked on transformative behavior of energy, Water and carbon in the critical zone II: Interactions between long- and short-term processes that control delivery, colloid mobility in soils, and physical mechanisms controlling CO2-Brine capillary trapping in the subsurface.<br /> <br /> Virginia Tech, in collaboration with Oregon State University and American University of Beirut in Lebanon, developed a new framework to describe how the porosity distribution of shrink-swell clay soils shifts with water content. In collaboration with Oregon State University, VT developed and field-validated a new economical and accurate instrument for measuring plot-scale runoff. Research group at VT has begun recently work on using a vapor sorption analyzer to analyze physical properties in shrink-swell clay soils, and started the development of new visualization techniques that can be used to demonstrate differences in soil properties and soil function.<br /> <br /> North Dakota State University, conducted laboratory soil column studies to determine the impact of soil salinity and sodicity level on soil hydraulic properties, soil shrinking and swelling of soils containing smectite clays Brine spills from oil and gas development were surveyed including spill sites, soil types, prior agricultural use, and management histories. The fate of the estradiol conjugate 17sulfate-17beta-estradiol (E2-17S) was investigated as a natural process that might explain the greater than expected detections of estradiol in the environment. <br /> <br /> University of Wyoming tested the 1-D vertical model for water, heat, and carbon fluxes in the soil-plant-atmosphere system using soil moisture & temperature data from three different ecosystems: A bare desert soil, a mixed-grass rangeland soil, and a snow-dominated mountainous forest soil. UW assisted with field work, maintained an automated soil moisture network consisting of 15 sites in Wyoming rangelands to assess the impact of drought on biomass production, improved three soil-snow monitoring stations and Conducted soil CO2 efflux monitoring at a mixed-grass rangeland site near Laramie, WY.<br /> <br /> University of California Riverside, offered short courses on how to use HYDRUS models at a) Czech University of Life Sciences, Prague, Czech Republic, b) Colorado School of Mines, Golden, CO, c) Research Center for Eco-Environmental Sciences, Chinese Academy of Science, China, d) to the participants of the Second Research Coordination Meeting (RCM) of the Coordinated Research Project on “Landscape Salinity and Water Management for Improving Agricultural Productivity” and e) at the Chinese Agricultural University, Beijing. Over 200 students participated in these short courses.<br /> <br /> University of California Riverside developed collaboration with University of Nevada-Reno to study salinity, developed collaboration with China Agricultural University on a project titled “Water Saving Agriculture” ad was invited to give a seminar at the project conference and served on USDA/NIFA panel.<br /> <br /> Texas A&M University organized sessions in American Geophysical Union Fall Meeting, characterized Hydrological and Linked Processes in Arid and Semi-Arid regions, and organized third In-situ and remote soil moisture sensing technology conference: challenges and opportunities in a changing World.<br /> <br /> University of Nevada activities have focused on submitting proposals to federal agencies and getting my lab set up. <br /> <br /> University of Kentucky organized short course on Spatial and Temporal Statistics at University of Valdivia, Chile and at University of Rio de Janeiro, Seropedica, Brazil. Additionally taught a course PLS 655 Spatial and Temporal Statistics during fall.<br /> <br /> Iowa State University evaluated the effectiveness of the thermo-TDR technique for monitoring the temporal dynamics of soil BD under field conditions, introduced a simple model for estimating thermal conductivity from soil properties, examined the SHB method for determining soil freezing and thawing rates, and performed sensitivity analysis for thermal properties and temperature measurements. Comparison between the results of tangent-line methods and second order BMO showed that for most of the waveforms, all of the methods provide similar results. Canopy chambers were constructed to measure ET in different cropping systems (prairie, corn, and soybean) during the 2013 and 2014 growing seasons.<br /> <br /> University of Idaho started a research project on irrigation optimization using soil tension measurements coupled with spatiotemporal variability in soil resources, continued work on soil terracettes including the collection of terrestrial lidar data, and Finalized data analysis for oxygen diffusion data collected on the ISS.<br /> <br /> Milestones<br /> <br /> USDA-ARS Research Laboratory, Bushland developed down-hole waveguide-on-access-tube TDR system developed in cooperation with CRADA partner Acclima, Inc. was and is nearing commercial availability. A new method for determining travel time from TDR waveforms was developed and tested. They developed and calibrated the PALMScot model of spatially varying infiltration, overland flow, soil water flux and plant growth and water uptake.<br /> <br /> Washington State University’s work on capillary forces and colloidal processes has led to better understanding of processes controlling environmental and biochemical processes in soils. They have developed numerical and experimental methods to predict, and measure capillary forces acting on colloidal particles in porous media and also shown that micro-scale results of colloid removal can be applied to colloid fate and transport in the capillary fringe of porous media. <br /> <br /> Oregon State University have determined that low molecular weight organic acids display a different spectral response when wet and dry but amino acids do not. regardless of the reported polarity and hydrophobicity, and the addition of a microbial community can initiate a strong spectral response in the alkyl region of a spectra when applied to organic matter or mineral soils.<br /> <br /> University of Minnesota found that lead was the only heavy metal found at concentrations that exceed its MCL at significant depths beneath stormwater infiltration practices. They found that the contribution of ground water to the baseflow of the Minnehaha Creek was very small (about 0.5%) compared to the amount of water estimated to recharge the contributing surficial aquifer. UM demonstrated that whole watershed phosphorus balances can be conducted and that the efflux of phosphorus out of the watershed in streamflow is only 5% of the total balance. <br /> <br /> University of California Riverside developed KDW model and modify it by combining with van Genuchten model (KDW-VG). <br /> <br /> Montana State University completed eddy covariance and micrometeorological observations along an entire winter wheat– spring wheat–fallow sequence commonly used in central MT.<br /> <br /> U.S. Salinity Laboratory showed that enhanced nanoparticle transport occurs as retention sites become occupied. This research suggests that nanoparticle movement in the environment may be substantial.<br /> <br /> ARS Researchers at Riverside, California developed a new agricultural systems model that can be used to manage irrigation and salinity while targeting submaximal crop yields. This research will help growers to predict end-of-season crop yields under drought conditions, when both the availability and quality of water for irrigation is limited.<br /> <br /> University of Delaware developed sampling and analysis protocols for quantification of colloids in different size fractions. They improved a pore-scale-model for predicting unsaturated hydraulic conductivity by incorporating surface roughness effects. <br /> <br /> New Mexico State University anticipates that the vadose-zone characterization technology will produce information that will greatly improve the assessment of vadose-zone source impacts on groundwater. Our evaluation of produced water composition and variability examines potential environmental impacts and the potential for partial treatment and beneficial use of this unconventional water source. The use of concentrate for growing halophytes would ensure cost-effective disposal technology and food security for semi-arid regions.<br /> <br /> University of Arizona developed a solid method for prediction of soil specific surface area and clay content from water vapor sorption isotherms. UA developed a novel 2-stage approach to predict the soil water characteristic from saturation to oven-dryness from the particle size distribution, significantly improved X-Ray CT data segmentation capabilities, and designed and fabricated a completely self-contained and fully automated GHG measurement system that consists of 12 multiplexed surface chambers connected to a FTIR spectrometer.<br /> <br /> Virginia Tech developed a novel method to quantify physical size of surface-connected macropore using shear-thinning fluids. VT developed a parsimonious framework that describes soil-water interactions in shrinking soils. VT developed and validated a low-cost and accurate method to measure surface runoff across a range of flowrates. They developed and validated a low-cost and accurate method to measure surface runoff.<br /> <br /> North Dakota State University improved the understanding of soil sodicity effects on soil pore size distributions in smectite dominated soils. A comprehensive model was used to simultaneously simulate the coupled sorption and transformation of a sulfate estrogen conjugate, 17 beta-estradiol-17-sulfate (E2-17S), in various soil-water systems.<br /> <br /> University of Arizona recruited a Native American research analyst who is a Dartmouth engineering graduate and who recently converted to a doctoral student and will conduct his dissertation work on collaborative hydrologic approaches to working with tribes.<br /> <br /> University of Arizona developed a new method for preserving substrate heterogeneity within large scale model inversions of saturated flow.<br /> University of Wyoming developed a new rigorous method to solve the coupled water flow and heat transport equations in soil and snow. UW developed a new method to weigh soil moisture anomalies as part of a Palmer-like drought index.<br /> <br /> University of California Riverside improved the Hydrus model.<br /> <br /> Texas A&M University developed fundamental understanding of dominant physical controls for soil moisture dynamics ranging from pore, field, catchment, watershed, to region.<br /> <br /> University of Nevada, Reno’s proposal was funded to assess the effects of long-term irrigation on biogeochemical processes in arid soils in Nevada. The research on use of halophytes would allow salt-affected areas to be used for agricultural purposes.<br /> <br /> University of Kentucky’s research results contributed to developing knowledge on scale-appropriate to enhance the management of vadose zone resources that benefit agricultural, and environmental sustainability. A new experimental field approach was evaluated. Experimental design was developed to allow the quantification of soil water and solute transport. The design studies conducted directly helped farmers’ fields without the transformation to the vicinity of a plot experiment at a research farm.<br /> <br /> University of California Davis developed a hydrodynamic flow model, simulating unsaturated flow in the soil and tree with stress functions controlling spatially distributed root water uptake and canopy transpiration. Using the van Genuchten functions, we parameterized retention and unsaturated hydraulic conductivity functions of the tree sapwood and soil. UCD used the recently developed identical-cylinder perfect-conductor model to solving for heat transport across the sensor with thick-walled probes. UCD developed an improved tensiometer design.<br /> <br /> Iowa State University developed an empirical model that estimates soil thermal conductivity as a function of water content, texture, and bulk density, an improved thermo-TDR sensor that measures dynamic, in situ bulk density following tillage, and an algorithm for analyzing waveforms obtained from short TDR probes. ISU developed relationships between saturated hydraulic conductivity and air permeability, based on continuum percolation theory.<br /> University of Idaho identified significant differences in oxygen diffusion thresholds in zero gravity root zones as compared to terrestrial gravity, characterized soil water storage in dryland agriculture as a function of crop rotations, and how these can be utilized to predict available soil water prior to planting, and provided the first morphological data set on soil pipes in forested watersheds to be used in future hillslope hydrological modeling.<br />

Publications

Impact Statements

1. W-3188 participants mentored >30 MS students, PhD students, and Post-doctoral researchers this year, and authored >100 peer-reviewed papers, book chapters, >100 abstracts and proceedings papers, and several technical reports in 2014.
2. USDA-ARS Conservation & Production Research Laboratory, Bushland patented down-hole waveguide-on-access-tube (WOAT) TDR instrument for soil water content and bulk electrical conductivity measurements that will provide a new tool for accurate deeper profile water content and change in storage determination to well below the root zone. The new TDR waveform analysis methods will extend the use of TDR in general and the WOAT system in particular to soils with larger bulk electrical conductivity than heretofore possible, extending management and research possibilities to more saline soils. The PALMScot model for landscape-scale simulation of spatially varying infiltration, overland flow, and soil water flux and plant growth should see use in similar landscape scale studies.
3. Washington State University?s results demonstrate that capillary fringe fluctuations are an effective means for colloid mobilization. The action of the moving air-water interfaces in the capillary fringe can scour colloidal contaminants, such as bacteria or colloidal metals from the vadose zone, thereby making these contaminants more mobile. They developed a linear regression equation that yielded useful information about variables that can influence fuel management and post-fire mitigation in Pacific Northwest forests. WSU demonstrated that bioretention systems can effectively retain Pb, Zn, and Cu from stormwater runoff. The results are useful in designing and assessment of bioretention facilities to protect surface and groundwater resources in Puget Sound.
4. Oregon State University have expanded our research objectives to be more inclusive of the interactions between geology, chemistry, biology, and physics in order that we might come to a multi-scale, multi-faceted mechanism for the development and amelioration of soil water repellency.
5. University of Minnesota showed that most metals of concern are attenuated sufficiently to meet water quality standards, as the stormwater infiltrates and percolated downward within a stormwater infiltration practice. However, the caviat here is that the sites need to be monitored for a longer period of time because migration of these contaminants can take longer than the time given for the study conducted. Their study showed that the geology underlying the surficial aquifer is not entirely conducive to ground water entry into the creek, but rather that there is a significant loss of surficial aquifer water to underlying aquifers. The implications of this are that the locations of the infiltration of the redirected stormwater need to be refined to make sure any infiltrated water will actually reach the stream
6. Montana State University shared field measurements freely with the Judith Basin Nitrogen Project for a watershed-scale study of soil and agricultural resource management
7. University of Delaware development of sampling and analysis protocols that go beyond the operational definition of colloids will allow more accurate quantification of inorganic and organic colloids in soil and water systems, thus allow better quantification and characterization of fate and transport of many substances, including (but not limited to) inorganic and organic contaminants, nutrients, OC, in surface and ground waters.
8. New Mexico State University anticipates that the vadose-zone characterization technology will produce information that will greatly improve the assessment of vadose-zone source impacts on groundwater and vapor intrusion. Specific applications for this information include decisions regarding implementation of vadose-zone remediation efforts, setting of remediation goals, optimization of remediation systems, and assessment of remediation system transition or closure. NMSU?s evaluation of produced water composition and variability supports examination of potential environmental impacts (e.g., spills) and the potential for partial treatment and beneficial use of this unconventional water source. NMSU work on growing chile with limited amounts of water by placing drips at 20 cm depth has potential for water saving. Early results on concentrate for agriculture could lead to cost-effective disposal of the reject coming out of an RO system.
9. The University of Arizona development of novel X-Ray CT segmentation algorithms aided numerous other researchers with projects that utilize X-Ray CT for soil and porous media research.
10. A hydrology extension program focusing on tribal stakeholders is a new program within the University of Arizona Cooperative Extension since 2011. . The University of Arizona Cooperative Extension presented, both through the tribal hydrology extension program and excellent university history in academic tribal programs and partnerships has the ability to address the water challenges facing tribes and through science and cultural sensitive approaches provide innovative solutions.
11. Virginia Tech developed an innovative method to quantify surface-connected macropores using shear-thinning solutions has attracted considerable attention. News magazine, and variations on the method are currently being developed by researchers at the American University of Beirut in Lebanon to study pore-size distributions and by researchers at Oregon State University to characterize fractured aquifers.
12. North Dakota State University developed analytical procedures to help close the mass balance of labile estrogenic compounds greatly increase the ability to understand the fate and transport processes of these compounds. An evaporation method for determining soil water retention was evaluated against other known procedures for soils varying in salinity, sodicity, and texture.
13. University of Wyoming developed the model capable to simulate water, heat, and carbon fluxes across a wide range of ecosystems is critically important in order to better understand the impact of global change (i.e. land use change, climate change, population increase, invasive species) on the earth system at a range of spatial scales. High temporal resolution monitoring data from different ecosystems therefore serve a critical need in validating model simulations to ensure that future predictions represent the true physics of the earth system.
14. Texas A & M showed that Iron and sulfur cycling is an important control on contaminant fate and transport. Using controlled soil column experiments we studied the effects of soil structure, specifically the presence of a soil layer, on linked biogeochemical and hydrological processes involving Fe and S cycling in the vadose zone. We developed an unmixing method, based on genetic algorithm and soil-vegetation-atmosphere transfer modeling to extract subgrid information of soil and vegetation from remotely sensed soil moisture that most land surface models use. A significant impact of our research is innovative use of satellite remote sensing as a tool to study soil moisture, soil hydraulics, and evapotranspiration. This work has impacted a wide spectrum of earth sciences including hydrology, water management, crop production, climate forecasts, drought assessment, flood prediction, groundwater recharge estimation, and pollution.
15. University of Kentucky?s major impact is the applicability of relatively simple sensors for spatial variability studies based on the fact that the spatial range of influence can overcome the small physical sphere of influence. Weather conditions, soil water dynamics and temperature dynamics alter the magnitude if CO2 respiration. However, after a period of one year, we detected a similar spatial behavior of CO2 emission in a field under grass and no-till land use. UK extended the current sensor-based nitrogen fertilization concept by a spatial variability component in the nitrogen response behavior. The outcome was a net increase of $19 per acre for the producer
16. University of California Davis measured and modeled methodologies that allow for hydrological characterization of the vadose zone across spatial scales, using inverse modeling techniques. The developed sensors will provide for alternative soil moisture sensors that are robust and simple-to-use. We work closely with companies and have a patent for in-situ soil solution nitrate measurements. In the past year, we are collaborating with various tree crop commodities in CA (almonds, pistachios, citrus, walnut) and state agencies (CDFA, FREP) in developing field monitoring protocols to assess water and nitrate leaching, and towards improved irrigation water and fertigation practices.
17. Iowa State University?s development of the improved thermo-TDR probe enables measurement of dynamic, in situ bulk density, which impacts transient water, heat, solute, and gas transport. This tool will aid numerous researchers with projects on field water, heat, solute, and gas transport
18. University of Idaho continued to developed measurement and monitoring methods addressing the characterization of mass and energy transport at the field scale using geophysical techniques easily deployable by land managers. These method aids in the characterization and forecasting of future water resources and their temporal availability and quality to the benefit of agriculture and the environment.
19. University of California Riverside focused on safe application of reclaimed wastewater, improvement of water management practices, identification of contributing sources of agrichemicals, and developing methods to mitigate non-point source pollutions. The information developed from our research has been used in presentations to local, national, international, as well as classroom instructions, promoting water conservations in various scales.
20. University of California Riverside continued supporting a large number of HYDRUS users from around the world at the HYDRUS website using various tools, such as Discussion forums, FAQ sections, and by continuously updating and expanding a library of HYDRUS projects. By 2014, over eighteen thousand HYDRUS users from all over the world registered at the HYDRUS website so that they could benefit from this activity, and HYDRUS-1D was downloaded more than ten thousand times.

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Report Information

Participants

Steve Loring, NMSU-AES, sloring@nmsu.edu
Mark Uchanski, NMSU/CSU, uchanski@nmsu.edu; mark.uchanski@colostate.edu
Lindsey du Toit, WSU, dutoit@wsu.edu
Kenny McFarland, Utah onion grower, kennymcfarlandfarms@gmail.com
Hanu Pappu, WSU Pullman, hrp@wsu.edu
Robert Ehn, CA Garlic and Onion Res. Bd, robertehn@sbcglobal.net
Steve Beer, Cornell University, svb1@cornell.edu
Diane Alston, USU, diane.alston@usu.edu
Christy Hoepting, Cornell University, cah59@cornell.edu
Sarah Pethybridge, Cornell University, sjp277@cornell.edu
Brian Nault, Cornell University, ban6@cornell.edu
Bill Dean, River Point Farms, bill.dean@riverpointfarms.com
Kerrick Bauman, L&L Ag Production (WA), kerrick@llfarms.com
David Whitwood, Crookham Company, davew@crookham.com
Ron Gitaitis, University of Georgia, dronion@uga.edu
Claudia Nischwitz, Utah State University, claudia.nischwitz@usu.edu
Tim Waters, WSU, twaters@wsu.edu
Clint Shock, OSU, clinton.shock@oregonstate.edu
Juan C. Brevis, Bayer Vegetable Seeds, juan.brevis@bayer.com
Morgan Reeder, Grower, mlreeder@yahoo.com
Curtis L. Marble, Grower, clmarblefarms@gmail.com
Lisa Marble, Grower, lisasmarble@gmail.com
Dan Drost, USU, dan.drost@usu.edu

Brief Summary of Minutes

Call to Order, Welcome, Business of the Day, Thank You

The meeting was called to order by Dan Drost, Utah State University, who organized the meeting. Dan welcomed everyone to the meeting, and thanked the sponsors of the meeting – Utah Onion Association, Western SARE, National Onion Association, and the Pacific Northwest Vegetable Association.

 

New W2008 Administrator and Working Group Update

Steve Loring was introduced as the new Administrative Advisor to W2008. He is based at New Mexico State University. Steve noted that this group needs to prepare our annual report within 30 days of this meeting (Jan. 10, 2016).

 

W2008 meeting with the National Onion Association (NOA) and National Allium Research Conference (NARC)

The next W2008 meeting will take place in conjunction with the NOA/NARC meeting in Savannah, GA on Nov. 30-Dec. 3, 2016. Appreciation was expressed to Ron Gitaitis for agreeing to organize the NARC meeting.

 

Oral State Reports:

California (given by Bob Ehn):

Production: Yields are down from 0.5 to 1.0 ton per acre in both onions and garlic. Because of the drought, growers were forced to rely upon ground water to supplement the minimal surface water allocations. As the season progressed, salt content in ground water increased with much higher levels of selenium and boron. Boron toxicity was evident in several onion fields in the Central Valley. The warm winter of 2014/2015, with reduced chilling hours/lack of cold exposure on the fall planted garlic, caused reduced bulb size. Some brooming (vegetative growth from developing cloves) was observed. Thunderstorms in late May in the Central Valley damaged some harvested onions, and garlic that were dug and windrowed experienced staining that forced fresh market fields to be rendered to dehydrators.

Pests/diseases: Thrips populations were low throughout the year in the desert, Central Valley, and northern Tulelake areas. There were reports of IYSV in the desert areas of southern California. Infected onion transplants in a nearby field that were being grown for seed seem to have been the origin of the virus, with surrounding dehydrator onion fields showing IYS symptoms on fields near the onion transplants. Only two white rot strikes were reported in the Central Valley this year. A combination of high soil temperatures and bulb development were not conducive to sclerotia infection and reproduction of the fungus. Much of the onion and garlic was grown outside of the normal production areas as processors and handlers had to source fields with reliable ground water sources. Downy mildew pressure was very severe in desert onion crops this year as above-average rainfall occurred during the growing season. Because of early summer rains and warm temperatures in the Central Valley, conditions for garlic rust infection periods were favorable, and fields were treated several times to get adequate control. Seed corn maggot/onion maggot: Severe pressure, primarily from seed corn maggot, was noted in the Tulelake area of northern California. Seed treatments with spinosad have given excellent control in the past - far superior to in-furrow treatment with chlorpyrifos. This year, the seed treatments did not provide adequate control, and in-furrow chlorpyrifos treatment was significantly better. We think the method by which seed was treated may have caused the product to wash off the seed and, thus, did not protect the seed.  

 

Georgia report (given by Ron Gitaitis):

There was an unusual amount of Botrytis leaf blight in some onions in early March. The overriding factor was that in the majority of these fields in which it was observed, there was a delay in the application of an SDHI product like Pristine, Fontelis, or Endura. Most organic fields suffered drastically from these infections as well. There was also some crop loss due to hail damage and heavy winds that laid down some foliage prematurely. There were a fair number of fields with onions experiencing some type of tip die-back. At the time it seemed that each field had something different going on (low pH, excessive Goal injury, etc.); however, they were spread over a multi-county area. Nothing was ever cultured from these onions at the UGA Plant Disease Clinic. There was a fairly severe outbreak of center rot in approximately 900 acres of onions grown in southern Georgia and northern Florida (outside of the defined Vidalia onion zone as defined by the marketing order). This outbreak occurred on new ground as well as on land previously used to produce onions. County agents made the observation that most of the onions were planted behind corn. There also was an unusual outbreak of center rot caused by Pantoea ananatis in the heart of the Vidalia onion-growing region (Toombs and Tattnall Counties). Particularly hard hit were the bulbs from the middle maturity group. Furthermore, those infections were somewhat unusual for center rot in that typical necrosis of upper leaves was absent. Instead, there generally was a reddish-colored leaf in the neck of the bulbs observed at grading, but it obviously did not originate from a dying leaf in the top foliage. A few millimeters below the discoloration in the neck, a very small area of grayish, gummy tissues developed. This discoloration and texture remained restricted and did not spread in to the rest of the bulb. It was speculated that physiological conditions initiated the syndrome resulting in secondary colonization by P. ananatis. One observation in that regard was that the middle maturity group experienced unusually high temperatures at a critical phase of bulbing when nutrients were being relocated from foliage to bulb. It was speculated that high temperatures at that critical period, in combination with P. ananatis, may have caused the unusual symptoms. Finally, there is a substantial amount of seedling blight caused by Pantoea ananatis in the seedbeds that are now being transplanted for the 2016 crop. It will be interesting to see if this plays out in to having increased center rot problems this spring.

 

Oregon Treasure Valley (report given by Clint Shock):

There have been a lot of heat units in the Treasure Valley this past season, and very little irrigation water. The season started very early. Record heat units were recorded in the 2014 season and again in the 2015 season. Onion bulbs aren’t finishing completely. The predominant symptom Clint has seen is not the dry scale reported by Lindsey, Tim, and Stuart (see below), but incomplete top end of the fleshy scales. Some cultivars seem worse affected than others, but it’s not clear if there’s a cultivar trend because of many confounding factors. They’re also seeing more bacterial bulb rots associated with this, and Fusarium proliferatum infection of these symptomatic bulbs has been very spotty. They don’t know what’s causing the dry upper end of all the fleshy scales. Some growers have shortened their rotations a lot, which may be contributing to problems. Thrips and IYSV were less severe than usual, despite the heat stress, because most growers have implemented good management programs.

 

Washington (report given by Lindsey du Toit and Tim Waters):

It was a very warm season in Washington State with high temperatures early in the season and extended periods of heat stress (22 days >100^oF in the Tri-Cities area, and the warmest temperature of 113^oF was recorded in late June). As a result, crops matured 2 to 3 weeks earlier than normal, and thrips numbers were very high early during the cropping cycle. Thrips damage was quite severe in some crops, as was IYSV incidence in some bulb crops in relatively close proximity to onion seed crops. In some fields, the early maturity resulted in smaller-than-normal bulb size and, therefore, lower-than-average yields. There was also significant damage from internal dry scale, a physiological response that appears to be triggered by extended periods of heat stress, and often is accompanied by secondary colonization of the collapsed, internal fleshy scales by bacteria and/or fungi. Some entire onion crops and bulb lots in storage were abandoned as the affected bulbs could not be culled effectively (symptoms are almost entirely internal). Fall temperatures were also warm, making good curing conditions in most onion crops. A few crops received late rain after undercutting and/or windrowing, which will likely result in decreased storage quality. Black mold incidence (exterior of bulbs) was at significant levels in some fields due to warm temperatures. The warm fall also resulted in significant damage to fall-planted, overwintering crops from onion leafminer. Normally, cool fall temperatures reduce their activity, but not this season. Some overwintering bulb crops were also damaged by fall armyworm and had to be treated for this pest. Overall, a rough year for onions in central Washington and there is concern about how bulbs will fare in storage.

Discussion ensued about heat stress and some of the other problems growers have been experiencing in the Pacific Northwest with some of the growers present at the meeting. One grower stated that onion seed alone costs ~$600/acre.

 

New Mexico (report by Mark Uchanski):

New Mexico onion growers have not reported problems with IYSV this season. They’ve had typical thrips and pink root pressure. Conditions have been moderate and slightly cooler than normal, with normal precipitation. Yields are OK. It’s been a good season overall.

 

Mark stated he would like to put the W2008 nomination in again for the Western Association of Agricultural Experiment Station Award. Seed the Open Discussion items below.

 

New York (report given by Christy Hoepting):

New York onion growers experienced a very dry start to the season (May), but June was very wet and some growers lost onion stands. It was a moderate season overall with consistent rains that resulted in good yields in general. Thrips were relatively well controlled as a result. There were a few outbreaks of downy mildew and Stemphylium leaf blight. Bulb rots were at average levels. In some grower-cooperator, bacterial rot field trials, soil fumigation with chloropicrin had no significant effect on soil populations of the three main onion bacterial bulb rot pathogens (Burkholderia cepacia, Enterobacter ludwigii, and Pantoea ananatis) or on the incidence of bulb rots at harvest. Applications of TerraClean likewise had no significant effect on the numbers of these bacteria in the soil or bulb rots at harvest. Applications of a vermicompost extract (‘worm poop tea’ as Christy’s daughter called it) had no significant effect on bulb rots when applied as a drench, but dipping transplant seedlings in the extract prior to transplanting reduced the incidence of bacterial rot by about 50%. One grower made weekly applications of ‘pool chlorine’ to half of a field of onions at a rate of 1 gal of product/1,000 gal tank of water (Steve Beer didn’t know the chlorine concentration of the product, but estimated the chlorine application was at ~100 ppm). The incidence of bulb rot at harvest was reduced 60% compared to the non-treated half of the field, and the grower estimated a 22% increase in bulb yield. The treated part of the field lodged 2 weeks later than the non-treated part of the field.

 

Clint Shock discussed the recommended use of chlorine dioxide rather than other forms of chlorine. Bill Dean noted that some growers in the Columbia Basin who use pivot-irrigation routinely apply chlorine at 1 gal/hour (~1 ppm chlorine) using a 12.5% a.i. commercial product to clean irrigation water and equipment (sometimes at every irrigation).

 

Seven onion cultivars were evaluated by Brian Nault’s program for onion thrips resistance in New York.  Six of the seven cultivars were short-day onions bred for southern production areas, while the other cultivar was bred for intermediate-day growing conditions. Unfortunately, the short-day cultivars did not grow well under western New York’s environmental conditions, and generally produced small plants and unmarketable bulbs; thrips resistance could not be assessed accurately. The intermediate-day cultivar showed signs of partial thrips resistance, but bulb yields were significantly less than standard cultivars for the region. Nonetheless, this intermediate-day onion cultivar shows promise for future thrips-resistance breeding projects.

 

Utah (report given by Dan Drost):

2015 has been a good year overall for Utah onion growers. 2015 was one of the hottest seasons on record and yet there were no days in Utah >100^oF, which was surprising. The record heat was largely a result of warm nights. Overall bulb yields and quality were good. Thrips were not excessive. IYSV came late into most fields (about the time of lifting), so there was little effect on yield. Dan has WSARE funding for a multi-year project looking at field border management for thrips and IYSV (see Focused Talks below).

 

Focused Talks

Presentations were given from 10 am to ~3 pm (excluding the lunch hour) on focused topics, as detailed in the meeting program (contact individual presenters to request copies of their presentations):

1. Progress in managing leaf diseases of onion in New York, featuring Stemphylium leaf blight - Christy Hoepting (Cornell University Cooperative Extension)


2. How fertility can affect sour skin severity and the expression of proteins associated with the plant systemic acquired resistance (SAR) pathway - Ron Gitaitis (Univ. of Georgia)


3. White rot management in garlic and onions and California’s “Water Woes” - Bob Ehn (CA Garlic and Onion Research Board)


4. Determining the presence of endophytic pathogenic bacteria in non-symptomatic onion necks or bulbs - Steve Beer (Cornell Univ.)


5. Onion internal dry scale: An emerging problem associated with climate change in the Pacific Northwest? - Lindsey du Toit (Washington State Univ.)


6. Systems Drivers for Managing Thrips/IYSV: Rotations, Borders and Nutrition Influences - Dan Drost (Utah State Univ.)


7. Controlling Insects Impacting Columbia Basin Onion Producers - Tim Waters (Washington State Univ.)


8. Onion insect pest management in onion with insecticides – the challenges ahead - Brian Nault (Cornell Univ.)

 

Open Discussion – Other Research Needs, Issues, Future Focus

• September 30, 2017 is when the current W2008 expires:
  
  
  
  • We need to write a new W3008 proposal in 2016, to be submitted before the W2008 expires.
  
  
  • The group agreed we should consider a new title that it not focused as intensely on thrips/IYSV because of the large success in managing these problems in onion and the emergence of other major issues for onion growers across the USA. An example of a suggested title is “Integrated Onion Pest and Disease Management” (with added terms such as “frontlines” or “solutions”).
  
  
  • A subcommittee of volunteers was formed to write this document: Brian Nault, Dan Drost, Hanu Pappu, and Lindsey du Toit.
  
  
  
  


• There is a need for a standing NARC planning committee to streamline the planning and succession process. This will be discussed in Savannah, GA in 2016


• Mark stated he would like to put the W-2008 nomination in again for the Western Association of Agricultural Experiment Stations Award. Steve Loring indicated the due date in the Directors’ Office is February 28, 2016.


• Brian Nault thanked Dan Drost and the Utah Onion Association for organizing this meeting in Salt Lake City.

 

Election of new W2008 secretary for 2016

Christy Hoepting from Cornell University kindly agreed to be the next Secretary. Officers for 2016:

Past Chair: Mark Uchanski

Chair: Tim Waters

Vice Chair: Lindsey du Toit

Secretary: Christy Hoepting

 

History of W1008/W2008 meetings for a historical perspective, compiled by Mark Uchanski and Chris Cramer:

2019: Internat. Soc. Edible Alliaceae with NOA, NARC, and W3008 in Madison, WI - summer

2016: NARC + NOA combined with W2008 in Savannah, GA

2015: W2008 in Salt Lake City, UT

2014: NARC + NOA and W2008 in Scottsdale, AZ

2013: W2008 in Denver, CO

2012: NARC and W2008 in Las Cruces, NM

2011: W1008/W2008 in Las Cruces, NM

2010: NARC and W1008 in Reno, NV

2009: W1008 + NOA in San Antonio, TX - Dec.

2008: W1008 in Denver, CO - Jan; NARC and W1008 in Savannah, GA - Dec.

2007: W1008 in Denver, CO - Jan.

Accomplishments

<p><strong>Objective 1. </strong><strong>Evaluate onion germplasm for greater levels of tolerance to <em>Iris yellow spot virus</em> (IYSV), other pathogens and thrips.</strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Colorado (T. Gourd)-</strong></p><br /> <p>Two onion variety trial sites were set up at Sakata Farms locations along the Front Range of Colorado. The Howard Farm averaged only 6.2 thrips per onion plant, and the Zaiss location averaged 14.8 thrips per plant. This low thrips pressure could explain why very little Iris Yellow Spot Virus (IYSV) was observed at either location in 2015.</p><br /> <p><strong>New Mexico (C. Cramer)</strong> &ndash; In the previous year, germplasm lines were identified that possessed a reduced number of thrips per plant or less severe IYS disease symptoms than most entries. Seed productions of these lines were necessary to have ample seed quantities for distribution in the future. A total of 56 germplasm lines were regenerated using a total of 123 different crossing cages.</p><br /> <p>&nbsp;</p><br /> <p>Original, intermediate, and advanced FBR-selected populations and one resistant and one susceptible check were evaluated for resistance to FBR. Both the resistant and susceptible check entries exhibited a high level of disease severity and incidence. With the high rate of disease development throughout the study, many of the selected populations did not perform well in terms of disease severity and incidence. The inoculation method of 3 x 105 sporesml-1 of FOC placed on a cut basal plate was very effective at causing disease in most bulbs. Selections were made for FBR-resistant bulbs using this method. In addition, seed was produced of FBR-resistant selections made in 2014. Seed was produced from a total of 22 different germplasm lines associated with this project. This will be used for evaluations to ascertain additional progress made for resistance to FBR.</p><br /> <p>&nbsp;</p><br /> <p><strong>New York (B. Nault, S. Beer, S. Pethybridge &amp; C. Hoepting)</strong> &ndash; Seven onion cultivars were evaluated for onion thrips resistance in New York. The short-day onion cultivars did not grow well under New York&rsquo;s environmental conditions and generally produced small plants and bulbs; thrips resistance could not be accurately assessed. The intermediate-day onion cultivar showed signs of partial thrips resistance, but bulb yields were significantly smaller than standard cultivars. Nonetheless, this intermediate-day onion cultivar shows promise for future thrips-resistance breeding projects.</p><br /> <p><strong>OREGON</strong> <strong>- (S. Reitz, C. Shock, E. Feibert, A. Rivera, &amp; M. Saunders) </strong>Early maturity and full season onion variety trials were conducted in 2015. The trials were grown under drip irrigation. All varieties were evaluated for their yield, maturity and susceptibility to thrips damage and IYSV. Varieties had significant differences in IYSV in 2015.</p><br /> <p>&nbsp;</p><br /> <p>Thrips populations and IYSV incidence were compared among four experimental breeding lines from Chris Cramer, NMSU, and three commercial cultivars. The experimental lines tended to have lower populations of thrips and IYSV severity than the commercial cultivars.</p><br /> <h4>&nbsp;</h4><br /> <p><strong>Utah (D. Drost)</strong> - Twenty-nine (29) commercially available Spanish onion cultivars were assessed for productivity, maturity and rated for IYSV. While symptom expression of IYSV in 2015 was very low, all varieties evaluated showed visual evidence of IYSV under field conditions. IYSV had little impact on onion bulb yield as summer conditions were favorable for plant growth and IYSV incidence occurred very late in the season. More work on the relation between IYSV incidence and storage is needed.</p><br /> <p>&nbsp;</p><br /> <p><strong>Washington (</strong><strong>T. Waters, L. J. du Toit, H. R. Pappu &amp; C. Wohleb</strong><strong>)</strong> - Onion genotypes (n = 35) were evaluated for resistance to stunting caused by <em>Rhizoctonia solani</em> anastomosis group (AG) 8 in a growth chamber at 15 ^oC. The trial was repeated. Resistance was defined as a lack of significant difference in plant height, root length, and/or total dry biomass between inoculated and non-inoculated plants of the same genotype. Of the 35 genotypes evaluated, 3, 16, and 3 demonstrated partial resistance to <em>R. solani</em> AG 8 for plant height, root length, and total biomass, respectively. Plant height, root length, and biomass of PX07713218 were not affected by the fungus in either trial; and R14885, R14888, and SN307 displayed partial resistance in both trials for two of the three onion growth parameters measured, and in one of the two trials for the third parameter. These four genotypes could be used in onion breeding programs to develop cultivars partially resistant to stunting caused by <em>R. solani</em> AG 8.</p><br /> <p>&nbsp;</p><br /> <p><strong>Objective 2. </strong><strong>Investigate thrips biology and IYSV epidemiology to improve management strategies</strong><strong>. </strong></p><br /> <p><strong>New York (B. Nault, S. Beer, S. Pethybridge &amp; C. Hoepting)-</strong> Co-applications of insecticides with either a non-ionic surfactant (Induce), a methylated seed oil (MSO), a mineral oil (JMS Stylet oil) or an organosilicone (Silwet L-77) were more effective for managing onion thrips than when insecticides were used alone. None of co-application treatments exacerbated the incidence of foliar diseases such as botrytis leaf blight, downy mildew, Stemphyllium leaf blight and purple blotch.</p><br /> <p>Early-season management of onion thrips continues to be most effective beginning with Movento compared with other products like Radiant.</p><br /> <p>A new product, Minecto Pro, which includes a combination of abamectin and cyantranilprole, was effective in managing onion thrips. The efficacy of Minecto Pro was similar to Exirel (cyantraniliprole), but numerically better than Agri-Mek.</p><br /> <p>Based on historical levels of onion thrips control using Radiant (spinetoram) in New York, there is a downward trend in the level of control over the past decade suggesting that resistance to spinetoram may be developing in onion thrips populations.</p><br /> <p><strong>OREGON</strong> <strong>- (S. Reitz, C. Shock, E. Feibert, &amp; M. Saunders)</strong>Two insecticide rotation trials were conducted to evaluate the effectiveness of various insecticides in managing thrips and IYSV. One trial included all foliar applied insecticides, and another trial featured insecticides applied through drip irrigation and by ground application. Movento and Agri-mek were effective in early season thrips management. Using moderately efficacious insecticides, such as azadirachtin at the beginning of a spray program, has been encouraging. This use pattern allows applications of Movento to be made later in the season so that Radiant remains the most effective insecticide for mid to late season thrips management.</p><br /> <p>&nbsp;</p><br /> <p>Programs with drip applied products performed as well as foliar applied products. Drip applications may reduce grower expenses by reducing overall application costs.</p><br /> <h4>&nbsp;</h4><br /> <p><strong>Utah (D. Alston, D. Drost &amp; C. Nischwitz)</strong> &ndash; Onion thrips and IYSV were evaluated in field and research trials from June until September. Thrips densities on plants were very low in June (10/plant), increased to moderate levels in July (36/plant) and were quite high in late August (92/plant) as the onions began to mature. There was no difference in thrips numbers between the different nitrogen levels in 2015. A likely reason is that all onion plots sampled in 2015 followed three previous years of alfalfa and one year of onion production. Alfalfa may have increased soil nitrogen levels thus negating differences between high and low nitrogen application rates. IYSV levels increased throughout the summer but did not impact productivity.</p><br /> <p>Sustainable production occurs when inputs, onion thrips, and IYSV are properly managed. Growers in Utah report little difficulty with thrips and IYSV severity was low in 2015. Growers are using USU research findings on lowering nitrogen input levels, working harder to keep field border weed free, and exploring the use of alternative crop rotations to help manage thrips numbers and IYSV incidence.</p><br /> <p>Selected weeds growing next to onion fields were sampled for IYSV and thrips in the 2015. Weeds found with thrips (adults, nymphs and eggs) include bindweed, flixweed, sowthistle, common mallow, and foxtail barley. Identification of IYSV hosts that can serve as a green-bridge from year-to-year is critical to target, treat, and remove plants with IYSV growing near onions..</p><br /> <p>&nbsp;</p><br /> <p><strong>Washington (</strong><strong>T. Waters, L. J. du Toit, H. R. Pappu &amp; C. Wohleb</strong><strong>)</strong> -Field plots of onion in Pasco, WA and grown using drip irrigation. Plots were established in a randomized complete block design with 4 replications. Foliar applications were made with a CO₂ pressurized sprayer. Sprinkler chemigation applications were made with a trailer-mounted research sprayer applying and drip applications were made by injecting insecticides into individual drip lines. Efficacy was evaluated four or five days after each application by counting the number of immature and adult thrips per plant on 10 individual plants per plot. At the end of the growing season, onion yield and size were evaluated.</p><br /> <p>&nbsp;</p><br /> <p>Using insecticides that are effective at controlling thrips increases yield and size class of dry bulb onions. Radiant and Lannate were found to be the most effective products while Movento, Verimark/Exirel and AgriMek provided good suppression of onion thrips. We also found that Radiant was more effective in the early season compared to Movento. Chemigation was an effective way to apply Lannate, Exirel and Radiant. Verimark was also effective when applied via drip injection.</p><br /> <p>&nbsp;</p><br /> <p>Acibenzolar-S-Methyl (ASM) is a functional analog of salicylic acid (SA) that activates local and systemic acquired resistance (SAR) responses in plants against a wide variety of pathogens. To explore the possibility of utilizing SAR as a control option, we first used two different hosts of IYSV, <em>Datura stramonium</em> and <em>Nicotiana benthamiana</em>, to study the ability of ASM in triggering SAR against IYSV infection. Quantitative descriptors based on both symptom expression and relative levels of IYSV nucleoprotein and viral small RNA were developed and used to determine the SAR in ASM- and buffer-treated plants. A significant reduction in virus levels in ASM-treated plants was noticed by ELISA and PCR. The level of SAR response was also assessed by measuring the IYSV lesion size and number on the inoculated leaves of ASM-treated plants. ASM-treated plants showed reduced symptoms compared to buffer-treated plants. This study could be useful in potentially developing novel SAR-based options for virus management.</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>Objective 3. Investigate the biology, ecology and epidemiology of other pathogens to improve management strategies.</strong></p><br /> <p><strong>Colorado (T. Gourd)-</strong></p><br /> <p>An evaluation of Mycorrhizal Fungi on Commercially Grown Onions in Colorado was conducted during the 2015. The objectives of this study were to use large scale on-farm test to demonstrate efficacy of MYKE Pro Specialty Crop P endomycorrhizal inoculant. The active ingredient is Glomus spp. We evaluated for enhanced seedling growth, increased pathogen resistance/protection of onions and increased onion yield (quality and quantity).</p><br /> <ul><br /> <li>The bottom line was no economic advantage was seen using a planter box application of MYKE Pro Specialty Crop P endomycorrhizal inoculant at two farm locations in 2015</li><br /> </ul><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Georgia (R. Gitaitis, B. Dutta, D. Riley, R. Srinivasan, &amp; A. Watson-Selph)</strong> &ndash;</p><br /> <p>Previously developed regression models consisting of concentrations of cations and cation ratios accurately predicted sour skin severity. In 2015 these models were used to identify healthy bulbs that had the highest and lowest levels of sour skin. RNA was extracted and used for transcriptomic analysis. Many proteins were expressed at significantly higher levels in bulbs with a higher copper to iron ratio which was also associated with reduced sour skin levels. Increased levels of important proteins that particularly have known functions in the systemic acquired resistance (SAR) pathway in plants, included: &gt;5,000 fold increase in universal stress protein A (USPA is very similar to Pto which is known to convey resistance in tomato); &gt; 4700 fold increase in B2 protein (increases hydrogen peroxide levels, a precursor for salicylic acid); &gt; 900 fold increase in enhanced disease resistance protein (EDR1 is involved in a MAP kinase cascade that regulates salicylic acid dependent defense responses); and &gt; 3900 fold increase in glutaredoxin (known to interact with non-expressor pathogenesis-related protein 1 (NPR1) which has a feedback control of salicylic acid production). The most important example of an elevated protein level of a SAR-connected protein in bulbs with a higher copper to iron ratio was a &gt; 5000 fold increase in the expression of pathogenesis-related protein 1 (PR1). PR1 is known to be regulated through the salicylic acid pathway and is a plant resistance protein whose production is regulated by NPR1. The PR1 protein identified had 85% similarity with PR1 from garlic.</p><br /> <p>&nbsp;</p><br /> <p>Field studies indicated that titanium dioxide nanoparticles doped with zinc, acibenzolar-S-methyl and cupric hydroxide had little effect on center rot. When the same treatments were evaluated in for postharvest rots due to sour skin caused by B. cepacia, cupric hydroxide applied weekly significantly reduced postharvest levels of sour skin. Evaluating acibenzolar-S-methyl in combination with different nutrients found that lowest levels of sour skin occurred in all treatments receiving gypsum. Onions with the highest levels of sour skin had all been treated with acibenzolar-S-methyl in combination with either iron, copper, manganese or zinc chelates. The highest level of sour skin occurred with the treatment of copper, calcium chloride, magnesium sulfate and acibenzolar-S-methyl and was significantly different from copper, calcium chloride and magnesium sulfate without acibenzolar-S-methyl indicating a possible negative interaction with the plant resistance inducing compound.</p><br /> <p>&nbsp;</p><br /> <p>A paper was published in the J. Econ. Entomol. entitled &ldquo;Thrips Settling, Oviposition and IYSV Distribution on Onion Foliage&rdquo;. Results from studies confirmed that distribution of thrips adults, nymphs, and eggs were skewed toward the base of the plant. The settling distributions of thrips adults and nymphs differed slightly from the egg distribution. In a field study, the results suggested that adults of different species appear to segregate along leaf length. Finally, thrips oviposition on 2-cm segments and Iris yellow spot virus positive leaf segments were quantified in the field, irrespective of thrips species. Both variables demonstrated a very similar pattern of bias toward the base of the plant and were significantly correlated.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Idaho (B. Schroeder)-</strong> The impact of curing temperature and duration on the development of storage rot caused by the bacterial pathogens Pantoea ananatis, Pantoea agglomerans, and Pantoea allii on onion bulbs was completed. As with previous studies, it was determined that curing onion bulbs with cooler temperatures for a longer duration will reduce the amount of rot caused by these pathogens if the bulbs were infected prior to storage.</p><br /> <p>&nbsp;</p><br /> <p>A DNA macroarray was developed for the detection of fungal and bacterial plant pathogens (26+) capable of causing onion bulb rot in storage. The DNA macroarray for the fungal pathogens was just evaluated for sensitivity and it appears to be able to detect ng levels of the pathogen present in a sample. It was determined that the DNA macroarray is able to detect the presence of Fusarium proliferatum in asymptomatic onion bulbs prior to curing. The DNA macroarray is being used to obtain pathogen incidence data to correlate with disease incidence in storage. A macroarray that readily detects latent infections by bulb rot pathogens will enable stakeholders to make informed storage management decisions.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>New York (B. Nault, S. Beer, S. Pethybridge &amp; C. Hoepting)-</strong> <strong>Bacterial Diseases of Onion</strong> Emphasis was placed on three bacterial pathogens,<em> Burkholderia cepacia</em>, <em>Enterobacter cloacae</em> and <em>Pantoea ananati</em>, known to cause great losses to New York onion growers. Plants were collected biweekly during the later two-thirds of the growing season from one grower in each of the three major onion-growing areas of New York State and analyzed to determine the degree of bacterial infection, infestation and susceptibility to the three bacterial pathogens.</p><br /> <p>Very little infection was detected visually in any samples until the last two collections, a few weeks prior to harvest of the crop. Infestation of bulbs varied depending on the pathogen and the location from which the plants were collected. Overall, pathogenic bacteria were isolated and identified from (4 to 24%) of symptomatic bulbs of growing plants. This suggested the hypothesis that the degree of infestation with pathogenic bacteria may indicate the extent of decay at harvest or following storage.</p><br /> <p>Generally, plants were susceptible to infection following inoculation with <em>P. ananatis</em> or <em>B. cepacia</em> at any age tested. Only 1 of 9 of the inoculated plants became symptomatic after prolonged incubation following inoculation with <em>E. cloacae</em> at the 6-leaf stage of growth.</p><br /> <p>In controlled inoculation and environment studies conducted in the laboratory, conditions were discovered that were conducive to the initiation and development of infection of growing onion plants that had reached the &ldquo;bulbing&rdquo; stage when inoculated with pure cultures of <em>B. cepacia</em>.</p><br /> <p>We evaluated four materials that may reduce bacterial rot. None of the materials had been tested rigorously previously for the control of bacterial rot of onions. The materials were: 1. Chloropicrin, 2. vermicompost extract, 3. TerraClear&reg;5, and &ldquo;Pool Chlorine&rdquo;.</p><br /> <p>Research plots were set up in 3 onion-producing regions of NY. At harvest bulbs were collected and each was cut and examined closely for evidence of bacterial decay. Based on these analyses, we concluded that the Chloropicrin fumigation did not affect rot, but vermicompost extract and TerraClear&reg;5 both reduced the percentage of rot somewhat. Treatment with sodium hypochlorite not only reduced the percentage of rot, but yields in the treated plots were substantially increased. Clearly, additional testing of the three promising materials is in order.</p><br /> <p>&nbsp;</p><br /> <p><strong>Fungal Diseases of Onion </strong>Onion production in NY is affected by a complex of foliar fungal diseases including downy mildew (<em>Peronospora destructor</em>), Stemphylium leaf blight (SLB; <em>Stemphylium vesicarium</em>) and purple blotch (<em>Alternaria porri</em>). The objectives of this research were to quantify the prevalence and incidence of foliar diseases and determine the symptoms associated with each of the pathogens in the &lsquo;target spot&rsquo; complex of onion. <em>Stemphylium vesicarium </em>was the most prevalent fungus associated with foliar disease in NY. The isolation frequency of <em>S. vesicarium </em>was not significantly affected by production type and was not significantly different in conventional and organic fields. Moreover, the frequency of the teleomorph of <em>S. vesicarium, Pleospora allii</em> was significantly higher in conventional fields than organic production. This may indicate that factors that are prevalent in conventional fields may be inducing the production of the teleomorph. The high frequency of <em>S. vesicarium </em>from foliar disease was irrespective of symptom type but most commonly with an asymmetric, necrotic lesion. In conventional fields, there was a low prevalence and incidence of <em>Peronospora destructor</em>, and <em>Botrytis </em>spp. The isolation frequency of <em>Alternaria porri</em> and <em>A. alternata</em> was significantly higher in organic than conventional production. These findings suggest the fungicides being used within conventional production are efficacious for the control of purple blotch, downy mildew and <em>Botrytis </em>spp.</p><br /> <p>In 2015, a replicated field trial evaluated the relative efficacy of currently registered and perspective fungicides for control of SLB. It was a randomized complete block design with 18 treatments and 5 replicates. An untreated control with no pesticide applications and an untreated with only onion thrips and downy mildew maintenance sprays were included.</p><br /> <p>A final SLB score was determined within each plot from six disease and plant health assessments from Aug-5 to Aug-30. A higher SLB score indicated more severe disease. All fungicide treatments had significantly lower SLB scores than the untreated (score 345), which was significantly lower than the untreated check with maintenance sprays (score 303). Maximum disease control was obtained with Luna Tranquility, Merivon, Inspire Super and Fontelis. Plots receiving fungicides belonging to FRAC 11 were not significantly different than the maintained untreated. Products with only FRAC 3 active ingredients and only FRAC 7 active ingredients provided significantly poorer disease control than Luna Tranquility, but not significantly different from Inspire Super or Fontelis, and between each other. The only product with just FRAC 9 was Scala, which provided mediocre control. SLB control was significantly improved when Scala was premixed with fluopyram (7) within Luna Tranquility. Another premix product with FRAC 9 was Switch, which performed similarly to Scala. Disease control in plots receiving Omega and Gavel were not significantly different to those receiving Scala and Switch.</p><br /> <p>In conclusion, Luna Tranquility was the most efficacious fungicide for controlling SLB in onions and this was attributed to the presence of fluopyram (7). Generally, products belonging to FRAC groups 3 and 7 provided the best control of SLB. The lack of efficacy from strobilurin products is concerning and the subject of further studies.</p><br /> <p><strong>OREGON</strong> <strong>- (S. Reitz, C. Shock, E. Feibert, A. Rivera, &amp; M. Saunders)</strong></p><br /> <p>In anticipation of the rules in the Food Safety Modernization ACT, research on onion production in relation to food safety continued in 2015 to compare the roles of wooden and plastic storage containers on contamination of onion bulbs with generic <em>Escherichia coli, </em>the FDA indicator for potential microbial contamination<em>. E. coli</em> levels of onions grown in furrow-irrigated plots using surface irrigation water with enhanced <em>E. coli </em>levels and harvested into old wooden boxes and sterilized plastic crates were compared with <em>E. coli</em> levels of onions grown under drip irrigation. After 6 weeks in storage, onions were prepared for shipment through removal of loose skin, roots and soil. Regardless of irrigation source, neither onions stored in plastic nor in wooden containers had detectable <em>E. coli </em>on the bulb exteriors or interiors. These results are consistent with our previous trials and indicate that storage container material does not affect the likelihood of <em>E. coli </em>contamination of dry bulb onions.</p><br /> <p>We repeated field studies to evaluate if surface irrigation systems reusing water may deliver bacteria to onions. We tested the potential for furrow irrigation using canal water with moderate or high levels of <em>E. coli</em> contamination and drip irrigation using canal water and well water free of <em>E. coli</em> to deliver <em>E. coli</em> to onion bulbs. The four irrigation systems applied water to onion. Water was sampled hourly for <em>E. coli</em> and the lateral movement of <em>E. coli</em> in the soil solution was tracked by soil samples. Onions were sampled for <em>E. coli</em> contamination. Consistent with previous results, furrow irrigation delivered <em>E. coli</em> to the soil immediately adjacent to the onion bulbs. <em>E. coli</em> movement under drip irrigation was mostly confined to near the drip tape and very little reached the onion bulbs, indicating that drip irrigation did not directly deliver <em>E. coli</em> to onions.</p><br /> <h4>In Oregon, surface irrigation water is commonly used for drip irrigation. We evaluated the use of chlorine dioxide to reduce bacterial loads in surface irrigation water. Growers often routinely use injections of chlorine dioxide at the end of irrigation cycles to control the growth of algae in drip irrigation lines. The current rates of chlorine dioxide for drip line maintenance (3 ppm) virtually eliminate E. coli.</h4><br /> <h4>Pennsylvania (B. Gugino) &ndash; In PA and NY, annual losses from bacteria range from 5 to 40%. However, these losses are variable, between fields and within the same field; in many cases the full extent of disease losses is not evident until harvest or after post-harvest storage. During 2015, efforts were directed towards the development of targeted research-based management strategies for reducing harvest and post-harvest losses due to bacterial bulb rots described below.</h4><br /> <h4>A replicated field trial evaluated the effect of nitrogen application timing and rate on onion bacterial disease incidence and marketable yield. The trial was a split plot randomized complete block design with nitrogen application timing as the whole plot and application rate as the sub-plot. Preliminary data analysis indicates that marketable yields were most influenced by disease pressure (inoculated vs not inoculated), the nitrogen rate (more nitrogen increased yields) rather than the timing of application.</h4><br /> <h4>Host resistance is one of the most important tools available for disease management. Identification of less susceptible cultivars that meet the marketing program criteria would provide growers with another management tool. A field trial was conducted to evaluate the susceptibility of ten onion cultivars to center rot. Each plot was subdivided and two alternate 20 ft rows were toothpick inoculated with a bacterial suspension containing a mix of three isolates of Pantoea ananatis and P. agglomerans, the two causal pathogens of center rot. Significant differences in yield between the cultivars were observed with cv. Great Western and Expression being the highest yielding and Sedona, BGS 300F1 Blush and Aruba being the lowest yielding. Cv. Aruba with the lowest yields also had the highest incidence of bacterial bulb rot at harvest as well as foliar disease symptoms during the season.</h4><br /> <h4>&nbsp;</h4><br /> <p><strong>Washington (</strong><strong>T. Waters, L. J. du Toit, H. R. Pappu &amp; C. Wohleb</strong><strong>)</strong></p><br /> <p><span style="text-decoration: underline;">Onion pink root Serenade Soil trial (L.J. du Toit):</span> A field trial was completed to evaluate Serenade Soil for management of onion pink root in a drip-irrigated, certified organic, onion bulb crop of the cv. Merenge in a commercial crop. Replicate plots of each of two Serenade Soil treatments were compared with control plots in each of two trial sites at the same field, one trial site with severe pink root pressure compared to the other site as a result of 2- vs. 4-year rotations out of onion, respectively. Serenade Soil treatments were applied after planting in a band over each double-row using a CO₂-pressurized backpack sprayer on 3 April. A second application of Serenade Soil was made on 24 April, and a third application on 22 May. In both trials, onion stands were significantly less in plots treated with Serenade Soil once or three times compared to control plots. The incidence of bulbs with pink root symptoms averaged 56.7% in the site with a 4-year rotation out of onions, compared to 100% pink root in the site with a 2-year rotation. In both trials, application of Serenade Soil once at 4 qt/acre or three times at 3-week intervals at 2 qt/acre/application did not reduce the incidence or severity of pink root.</p><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Onion stunting caused by <em>Rhizoctonia</em> spp.: (L.J. du Toit):</span> Onion stunting is an important soilborne disease on very sandy soils in the Columbia Basin. Isolates of <em>Rhizoctonia</em> spp. were obtained from soil and onion plant samples collected from inside and outside patches of stunted plants in 29 fields. Based on sequence analysis of the internal transcribed spacer (ITS) rDNA region, 13 anastomosis groups (AGs) or subspecies were detected. The most frequent was <em>Waitea circinata </em>var.<em> circinata </em>(25%), followed by <em>Rhizoctonia solani</em> AG 3 (17%), <em>R. solani</em> AG 4 (14%), <em>Ceratobasidium </em>sp. AG A (10%), <em>R. solani</em> AG 8 (7%), <em>Ceratobasidium</em> sp. AG K (6%), <em>R. solani</em> AG 2-1 (6%), <em>W. circinata </em>var. <em>zeae </em>(6%),<em> R. solani</em> AG 5 (4%), <em>Ceratobasidium </em>sp. AG G (2%), <em>R. solani </em>AG 11 (2%), and <em>R. solani </em>AG 1-1B and AG 10 (each &lt;1%). However, the distribution of AGs and subspecies varied depending on whether soil or onion plant samples were collected within or adjacent to patches of stunted onion plants. In an attempt to predict the risk of onion stunting prior to planting, DNA concentrations of AG 2-1, AG 3, AG 4, and AG 8 were quantified from bulk soil samples from nine fields. Pre-plant DNA concentrations did not correlate significantly with the amount of stunting observed during the growing season. In contrast, the frequency of isolation and DNA concentration of <em>R. solani </em>AG 8 detected in soil sampled during the growing season were greater from inside patches of stunted onion plants than from adjacent healthy areas of one but not for another onion crop. AG 2-1, AG 3, and AG 4 DNA concentrations did not differ significantly in soil sampled inside vs. outside stunted patches in the fields sampled in either year. Relationships between the number of bulbs harvested or bulb weight vs. severity of stunting were defined using correlation and regression analyses for six onion cultivars. Onion stunting reduced the average marketable bulb yield by 25 to 60% within stunted patches of the six cultivars. Stunting did not reduce onion plant stand but consistently reduced bulb size, and yield.</p><br /> <p>&nbsp;</p><br /> <p><strong>Objective 4. </strong><strong>Facilitate interaction and information transfer between W2008 participants, the onion industry and other stakeholders.</strong></p><br /> <p><strong>Colorado (T. Gourd)-</strong></p><br /> <p>The Northern Colorado Onion Variety Trials Field Tour was held on Friday, September 4.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Idaho (B. Schroeder)-</strong> The University of Idaho Plant Pathology laboratory has provided diagnostic services to the onion stakeholders throughout 2015 using the DNA macroarray and detected Fusarium proliferatum a fungal pathogen.</p><br /> <p><strong>New York (B. Nault, S. Beer, S. Pethybridge &amp; C. Hoepting)-</strong> As a result of onion growers&rsquo; following the Cornell-recommended IPM program for thrips, effective management of onion thrips was achieved with nearly 2 fewer insecticide applications. This reduction in insecticide use translated into an average savings of $50 per acre in insecticide costs. We estimated that 75% of the onion growers in New York have adopted this program, thereby saving these growers approximately $375,000 in 2015.</p><br /> <p><strong>Oregon</strong> <strong>- (S. Reitz, C. Shock, E. Feibert, &amp; M. Saunders)-</strong>The Oregon project has continued to transfer information pertinent to IYSV and thrips biology and management to growers, other onion industry parties, and the public through numerous meetings, field days, workshops, publications, and the internet. The Malheur Experiment Station hosted field days on July 8 and August 25 and a stop on the NOA tour on July 17. Results have also been presented at the Idaho-Malheur County Onion Growers Association Meeting, Pacific Northwest Vegetable Association Meeting, and the Treasure Valley Irrigation Conference.</p><br /> <p><strong>&nbsp;</strong></p><br /> <h4>Pennsylvania (B. Gugino) &ndash; In Pennsylvania the research results were disseminated at several local and regional vegetable grower meetings/conferences both in-state and out-of-state throughout 2015. Results were also disseminated throughout the season through one-on-one with the growers. We continued to disseminate the Diagnostic Pocket Series as well as the Onion Health Management and Production bulletin to interested growers and other stakeholders and wrote an article for the grower publication Onion World.</h4><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Utah (D. Alston, D. Drost &amp; C. Nischwitz)</strong> &ndash; USU hosted; winter onion meetings (56 attended) in February 2015 in Brigham City, UT; a summer field tour (52 attended) in August 2015; and Drost gave two presentations on Utah&rsquo;s systems approach to managing onion thrips and IYSV to the onion industry (220 attended) of Idaho, Oregon and Washington in November 2015 (see dissemination section). Two presentations were made at the W2008: Biology and Management of Iris Yellow Spot Virus, Other Diseases, and Thrips in Onions Regional Meetings on Dec 10 in Salt Lake City describing Utah based research findings.</p><br /> <p>&nbsp;</p><br /> <p><strong>Washington (T. Waters, L. J. du Toit, H. R. Pappu &amp; C. Wohleb) </strong>In Washington, results from the thrips insecticide efficacy results were shared at the WSU Onion Field Day, several grower meetings, and by a written report. Using the most effective insecticides improve their yields and reduce the incidence of IYSV, therefore improving yield, quality, and profitability of producers. An impact report by Washington State University (<a href="http://ext100.wsu.edu/impact/improving-insect-management-in-dry-bulb-onions-in-the-columbia-basin/">http://ext100.wsu.edu/impact/improving-insect-management-in-dry-bulb-onions-in-the-columbia-basin/</a>) cites the importance of this work and how widely adopted these practices are by Washington Onion Producers.</p>

Publications

<p>Alston, D. G., 2015. Growing cover crops for pest management. Utah Pests News, Utah State &nbsp;&nbsp; University Extension, 9(Fall). <a href="http://utahpests.usu.edu/files/uploads/UtahPests-%09Newsletter-fall15.pdf">http://utahpests.usu.edu/files/uploads/UtahPests-Newsletter-fall15.pdf</a></p><br /> <p>Asselin, J.E., J.M. Bonasera, and S.V. Beer. 2016. PCR Primers for detection of <em>Pantoea ananatis</em>, <em>Burkholderia</em> spp., and <em>Enterobacter</em> sp. from onion. Plant Disease. 100: 1-11.</p><br /> <p>Asselin, J. E., J.M. Bonasera, and S.V. Beer. 2015. New York bacterial rot research update: Critical factors. <em>Onion World</em> 31(3):20-23.</p><br /> <p>Buckland, K., Alston, D. G., Reeve, J., Nischwitz, C., &amp; Drost, D. T. Trap crops in onion to reduce onion thrips and Iris yellow spot virus: Environmental Entomology/Entomological Society of America. (Submitted).</p><br /> <p>du Toit, L.J. and Derie, M.L. 2015. 2014 Onion pink root Serenade Soil efficacy trial, Connell, WA. Research report submitted to Bayer CropScience, Feb. 2015. 4 pp.</p><br /> <p>du Toit, L.J., Waters, T., and Reitz, S. 2016. Internal dry scale and associated bulb rots of onion. Extension Bulletin PNW 686. <em>In press.</em></p><br /> <p>du Toit, L.J., Waters, T., and Reitz, S. 2015. Internal dry scale and associated bulb rots: Bane of the 2014 Pacific Northwest onion season. Onion World May/June 2015:4-7.</p><br /> <p>Gill, H.K., H. Garg, A.K. Gill, J.L. Gillett-Kaufman, and B.A. Nault. 2015. Onion thrips &nbsp; (Thysanoptera: Thripidae) biology, ecology, and management in onion production systems. J. Integ. Pest Mngmt. 6(1): 6. DOI: 10.1093/jipm/pmv006.</p><br /> <p>Gugino, B.K. and E.E. Pfeufer. 2015. Bacterial disease management of onion. 2015 Mid-Atlantic &nbsp; Fruit and Vegetable Convention Proceedings, Pennsylvania Vegetable Growers Association, Richfield, PA. pp. 79-81.</p><br /> <p>Hoepting, C.A. 2015. New top performing pesticides now registered in onions in New York. March 1, 2015 <em>Veg Edge</em>, 11(3): 136-145.</p><br /> <p>Hoepting, C.A. 2015. Onion thrips breaking spray threshold in upland transplanted onion.&nbsp; May 27, 2015, 2015 <em>Veg Edge</em>, 11(7): 9-10.</p><br /> <p>Hoepting, C.A. 2015. The conflicts of simultaneous control of onion thrips and Botrytis leaf blight in onions. June 17, 2015 <em>Veg Edge</em>, 11(10): 6-7.</p><br /> <p>Hoepting, C.A. 2015. Management of Summer Leaf Diseases in Onion: Target Spot Diseases. July 1, 2015, 2015 <em>Veg Edge</em>, 11(13): 6-7.</p><br /> <p>Hoepting, C.A. and B.A. Nault. 2015. Strategic Management of Onion Thrips in Onions. July 15, 2015, 2015 <em>Veg Edge</em>, 11(14): 4.</p><br /> <p>Hoepting, C.A. 2015. Causes of Outer and Inner Leaf Dieback in Onions. July 22, 2015, 2015 <em>Veg Edge</em>, 11(15): 5.</p><br /> <p>Hoepting, C.A. 2015. Scouting Tips for Identifying Downy Mildew in Onions. July 29, 2015, 2015 <em>Veg Edge</em>, 11(16): 5.</p><br /> <p>Hoepting, C.A. 2015. Managing Downy Mildew of Onion: Control of target Spot Diseases is Critical. August 5, 2015, 2015 <em>Veg Edge</em>, 11(17): 4-5.</p><br /> <p>Hoepting, C.A. 2015. <em>Iris Yellow Spot</em> Virus of Onion. August 12, 2015, 2015 <em>Veg Edge</em>, 11(18): 3.</p><br /> <p>Hoepting, C.A. 2015. Using Ridomil to Manage Downy Mildew in Onion. August 12, 2015,&nbsp; 2015 <em>Veg Edge</em>, 11(18): 6.</p><br /> <p>Hoepting, C.A. 2015. Managing Stemphylium leaf blight and downy mildew. <em>Onion World</em>,&nbsp; 31(7): 34-37.</p><br /> <p>Maughan, T., D. Drost and N. Allen. 2015. Vegetable Irrigation: Onion. Utah State University Cooperative Extension Bulletin. <a href="http://digitalcommons.usu.edu/extension_curall/723/">http://digitalcommons.usu.edu/extension_curall/723/</a></p><br /> <p>Nault, B.A. 2015. Onion thrips management: Crisis averted? What&rsquo;s next?, 4 pgs. Empire State &nbsp; Producers EXPO. January 22, 2015. Syracuse, NY. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <a href="http://www.hort.cornell.edu/expo/proceedings/2015/onions/Thrips%20management%25%0920crises%20averted.pdf">http://www.hort.cornell.edu/expo/proceedings/2015/onions/Thrips%20management%20crises%20averted.pdf</a></p><br /> <p>Nault, B.A. 2015. Onion maggot and onion thrips management in onion. <em>Onion World</em> 31(2): &nbsp; 16-19.</p><br /> <p>Pappu, H.R. 2015. Thrips-transmitted <em>Iris yellow spot virus</em> &ndash; A threat to onion sustainability. Agricultural Research Journal 52: 10-12</p><br /> <p>Pfeufer, E., C. Hoepting, and B. Gugino. 2015. Advances in managing onion bacterial diseases in the Northeastern U.S. Onion World 31(6): 22-27.</p><br /> <p>Rinehold, J., Bell, N., Waters, T.D., &amp; McGrath, D. 2015. Vegetable Insect Pests. In Craig Hollingsworth (Eds.), 2015 Pacific Northwest Insect Management Handbook Corvallis, OR: Oregon State University.</p><br /> <p>Sharma-Poudyal, D., Paulitz, T.C., and du Toit, L.J. 2015. Evaluation of onion genotypes for resistance to stunting caused by <em>Rhizoctonia solani </em>AG 8. HortScience 50:551-554.</p><br /> <p>Sharma-Poudyal, D., Paulitz, T.C., and du Toit, L.J. 2015. Stunted patches in onion bulb crops in Oregon and Washington: Etiology and yield loss. Plant Disease 99:648-658.</p><br /> <p>Sharma-Poudyal, D., Paulitz, T.C., and du Toit, L.J. 2016. Timing of glyphosate applications to wheat cover crops to reduce onion stunting caused by <em>Rhizoctonia solani</em>. Plant Disease 100: <em>accepted Nov. 2015 pending minor revisions, revised &amp; re-submitted Dec. 2015. </em>PDIS-10-15-1234-RE</p><br /> <p>Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders. 2015. Response of onion yield, grade, and financial return to plant population and irrigation system. HortScience 50(9):1312-1318.</p><br /> <p>Shock, C.C., J.M. Pinto, E.B.G. Feibert, and C.B. Shock. 2015. Optimal irrigation criteria for drip irrigated onions. Growing Produce. March 24, 2015.</p><br /> <p>Smith, E.A. 2016. Patters of dispersal activity of onion thrips, <em>Thrips tabaci</em> Lindeman, in onion ecosystems. Cornell University, PhD. Dissertation. Pp. 131.</p><br /> <p>Smith, E.A., M. Fuchs, E.J. Shields, and B.A. Nault. 2015. Long-distance dispersal potential for onion thrips (Thysanoptera: Thripidae) and <em>Iris yellow spot virus</em> (<em>Bunyaviridae</em>: <em>Tospovirus</em>) in an onion ecosystem. Environ. Entomol. 44(4): 921-930. DOI: 10.1093/ee/nvv072.</p><br /> <p>Vahling-Armstrong, C., Dung, J.K.S., Humann, J.L., and Schroeder, B. K. 2015. Effects of postharvest onion curing parameters on bulb rot caused by Pantoea agglomerans, Pantoea ananatis and Pantoea allii in storage. Plant Pathology, http://onlinelibrary.wiley.com/doi/10.1111/ppa.12438/epdf</p><br /> <p>Tripathi, D., G. Raikhy, and H.R. Pappu (2015). Movement and nucleocapsid proteins coded by two tospovirus species interact through multiple binding regions in mixed infections. Virology 478:143-53. doi: 10.1016/j.virol.2015.01.009</p><br /> <p>Tripathi, D., G. Raikhy, R. Dietzgen, M. Goodin, and H.R. Pappu (2015). In vivo Localization of Iris yellow spot virus (Bunyaviridae: Tospovirus)-encoded Proteins and Identification of Interacting Regions of Nucleocapsid and Movement Proteins. PLoS ONE 10(3): e0118973. doi:10.1371/journal.pone.0118973</p><br /> <p>Tripathi, D., and H.R. Pappu (2015). Evaluation of Acibenzolar-S-Methyl-Induced Resistance against Iris yellow spot tospovirus. European J. Plant Pathology 142:855&ndash;864. DOI 10.1007/s10658-015-0657-0 E.</p><br /> <p>Waters, T.D. and Skoczylas, J.C. 2015. Thrips Control in Dry Bulb Onions in Washington State, 2012. Arthropod Management Tests. Report #E70.</p><br /> <p>Waters, T.D. and Skoczylas, J.C. 2015. Thrips Control in Dry Bulb Onions in Washington State, 2014. Arthropod Management Tests. Report #E72.</p><br /> <p>Waters, T.D. and Skoczylas, J.C. 2015. Thrips Control on Dry Bulb Onions Using Overhead Chemigation of Insecticides, 2014. Arthropod Management Tests. Report #E71.</p><br /> <p>Wohleb, C.H. and Waters T.D. Yield, Quality, and Storage Characteristics of Onion Cultivars in the Columbia Basin of Washington. HortTech. <em>Submitted</em>.</p><br /> <p>Zaid, A.M., J.E. Asselin, and S.V. Beer. 2016. Detection of <em>Burkholderia cepacia</em> in onion planting materials and onion seeds. Chapter 22 in M. Fatmi and N. W. Schaad, eds. APS Manual on Detection of Plant Pathogenic Bacteria in Seed and Planting Material. 2nd Ed. APS Press. St. Paul, MN. (In Press).</p>

Impact Statements

1. The knowledge that higher curing temperatures exacerbate the development of storage rot caused by the bacterial pathogens provides stakeholders with a management decision tool. If they know that the crop is at risk for bacterial storage rot, they can choose to cure bulbs using lower temperatures. This will help to reduce losses due to onion bulb rots in storage and increase onion production efficiency and profitability.

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Report Information

Participants

Hoori Ajami, UC Riverside; Shahila Beegum, UC Riverside; Markus Berli, DRI Las Vegas; Maria Dragila, Oregon State University; Markus Flury, Washington State University; Sarah Helalia, UC Riverside; Bob Horton, Iowa State University; Yan Jin, University of Delaware; Scott Jones, Utah State University; Maziar Kandelous, UC Davis; Honeyeh Kazemi, University of Arizona; Thijs Kelleners, University of Wyoming; Jing Liang, UC Riverside; Steve Loring, New Mexico State University; Laura Rosales, Nevada State College; Javier Reyes, University of Kentucky; Hirotaka Saito, UC Riverside; Rose Shillito, DRI Las Vegas; Manoj Shukla, New Mexico State University; Jirka Simunek, UC Riverside; Ole Wendroth, University of Kentucky; Jing Yan, University of Delaware; Michael Young UT Austin; Cheng Yu, UC Riverside; Wei Zhang, Michigan State University; Xi Zhang, University of Kentucky

Brief Summary of Minutes

January 2 2017. Chair brought the house to order at 1 PM.

 

Markus Flury (Washington State University) Discussed colloid fate and transport associated with the movement of air-water interfaces in contaminated unsaturated media; Fate of pollutants moving through engineered bio-retention systems focusing on nitrates, DOC, and organically complexed copper.

Jirka Simunek (UC Riverside) presented various updates and applications of the Hydrus family of codes, including new module for furrow irrigation, development of new recommendation drip irrigation associated with FAO-56Dual Approach, incorporation of the Richard’s equation to the DSSAT crop model; collaborated in two review papers on soil modeling and Hydrus applications. Jing Liang (Graduate Student under Jirka Simunek) discussed improved models for overland flow using Hydrus-1D for more accurate generation of predictive hydrographs associated with CAFO. Sahila Beegum (Graduate Student under Jirka Simunek) Discussed integration of solute transport in Hydrus to link to Modflow.

Scott Jones (Utah State University) Discussed improvements to the heat pulse probe, and the complexities of quantifying soil water content in a rock soil system. 

Steve Loring (New Mexico State University) discussed the need to identify and emphasize the impact of our scientific activities.

 

Meeting closed for the day at 5:00 pm

 

January 3 2017. Chair brought the house to order at 8:30 AM.

 

Markus Berli (DRI, Las Vegas) Discussed their work to improve the hydrologic impact of solar panels in desert landscapes; use of remote sensing to improve characterization of desert tortoise habitat.

Maziar Kandelous (UC Davis) Discussed leaching of water and nitrate below the root zone using water balance, Darcy-Equation, and numerical modeling. 

Manoj Shukla (New Mexico State University) discussed the impact of brackish water on the timing of flowering and on the yield of chile peppers, and how to manage brackish water application to reduce detrimental impact on soil properties; field studies using zeolites to support isolated plants in highly arid ecosystems.

Maria Dragila (Oregon State University) Presented work to determine the efficacy of soil solarization as soil disinfecting method for the Pacific Northwest; investigation on the transport dynamics within microfractures in the epikarst; continuing investigation on the impact of soil biology on soil water dynamics.

Michael Young (University of Texas, Austin) He used his time to encourage the broadening of the participation of the soil physics community in global and national cross-cutting communities, to avoid duplication of effort, determine where the gaps are in soil science research and drive a new generation of collaborations. He introduced the international GEWEX network for scientific collaboration, and encouraged soil physicists to participate in the formation of the new SoilWat Panel. Michael then introduced two documents released recently by the White House. The first is a “Fact Sheet of new Steps to Advance Soil Science.” It is a summary of on-going and upcoming federal initiatives to advance soil research. The list includes several institutes that are represented in our multi-state project. The second document is a draft “Framework for a Federal Strategic Plan for Soil Science” prepared by a 15-person working group drawn from federal agencies. Nancy Cavallaro, the NIFA representative of W3188 is one of them. Michael Young has had contacts with the group and he presented to the group in November. He suggested and agreed to collect comments until January 8^th and send on behalf of this group.

 

Business meeting (led by Teamrat Ghezzehei)

 

1. The presentation by Michael Young triggered a substantive and animated discussion on the future research direction for soil physics to address the concerns listed in the draft Framework released by the White House, to increase the awareness of the relevancy of soil physics to other disciplines and to stimulate increased funding support for important advances in soil physics research. The discussion has continued via email. Topics brought out during the discussion included: Tying instrument development to questions rather than to physical properties; what frontiers should be pushed?; strengthen the continuum of discovery, development and delivery of knowledge; upscaling of function such as the relationship between soil biology and soil health; enhance collaboration between soil physics and biogeochemistry to advance understanding of carbon sequestration; soil physics feeds into agriculture, hydrology and all of environmental sciences - identify future contributions; find venues to highlight the expertize that resides at universities; increase the infrastructure of soil science research so departments are more effective.

 

2. Michael volunteered to collect the thoughts of the group and submit these to the working group responsible for the Draft Framework for a Federal Strategic Plan for Soil Science. Input to Michael should take the form of a short statement of how your research is related to the three categories of threats to soil resources identified in the framework: land-use/land-cover change, unsustainable land management practices, and climate and environmental change.

 

3. The members who were present unanimously selected Hoori Ajami to be the secretary of the project for 2017. Hoori recently joined UC Riverside as an Assistant Professor of Hydrology.

 

4. New members: Hoori Ajami (UC Riverside), Wei Zhang (Michigan State) and Maziar Kandelous (Oregon State). They are still not included in the mailing list, so please add them individually to any messages you send through the mailing list. 

 

5. Consider joining the International Soil Modeling Consortium. The mission and activities of ISMC are relevant to most members of this project.

 

6. If you have not sent your reports yet, please do so ASAP. You will hear from Maria and Hoori about planning of next year’s meeting. 

 

7. Group photograph was taken (Thank you Ole and Markus)

https://www.dropbox.com/s/vzdd16j6zvhgwbb/DSC_0314.jpeg?dl=0

 

8. Steven Loring (W-3188 Administrative Advisor, NMSU) addressed the group and answered questions regarding the future path for the group. Emphasized that attention needs to be paid to the impact of research ventures. Funding support for this research focus depends on the ability of researchers to clearly and accurately demonstrate the value of their work.

 

Hoori Ajami (UC Riverside) discussed the application of integrated groundwater-land surface model for large scale catchment simulations in order to characterize feedback processes between the land surface and subsurface.

Yan Jin ( and group, University Delaware) discussed investigation of colloid attachment to the surface of food products associated with the disinfection of commercial fruits and vegetables; using turbidity measurements to quantify the concentration of colloid fraction < 45 microns.

 

January 4 2016. Chair brought the house to order at 8:30 AM.

Bob Horton (Iowa State University) presented an algorithm to correct for deviations of the tines in TDR thermal probes; an intriguing model for a capillary barrier; production of biochar with zero-valent-iron made from lignin and magnetite via slow pyrolysis process for the purpose of degrading TCE; transportation study on the effect of concrete slurry on vegetation.

Dalia Kool (Iowa State University) Presented investigation in vineyards to study partitioning of irrigation water to plants, soil and atmosphere, focusing on the goal to maximize the proportion of water to plants over soil and atmosphere.

Ole Wendroth (University of Kentucky) presented research results on the impact of stones on soil hydraulic properties, and showed that an existing model would allow converting the soil water retention behavior known for a stone-free soil into the water retention of a soil whose volume is occupied with stones by 40 %, while a conversion algorithm for hydraulic conductivity behavior does not exist yet and is the objective of current experiments. Xi Zhang (PhD Student of Ole Wendroth) commented on the capacity of models based on soil texture, such as Rosetta, to predict field Ksat, and demonstrated that it is not possible for such models to predict Ksat because Ksat is controlled by structure rather than texture. Javier Reyes (PhD Student of Ole Wendroth) Investigated the minimum number of valid landscape subdivisions necessary to optimize the success of precision irrigation practices.

Accomplishments

<ol><br /> <li><strong> Short-term Outcomes</strong></li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong>University of Arizona</strong> <strong>(Marcel Shaap)</strong>: Developed initial (2D) version of pore-scale colloid code developed and tested for low and high ionic strengths; Wrote seven chapters of an 11-chapter textbook; Conducted first phase of comparison of drought indices and soil moisture simulations; Collaborated with Robson Armindo (Universidade Federal do Paran&aacute;) regarding development of pedotransfer functions for tropical soils; Improved hierarchical pedotransfer function to be distributed as Rosetta3 (python source-code). PTF-assisted inversion technique published.</li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Improvement of previously developed segmentation algorithms, and improved method for calculating interfacial/surface areas from X-Ray CT images; Developed a novel method to estimate the cation exchange capacity (CEC) of soils from water vapor sorption isotherms. Collaborative activities: improved method to determine the SWC from hyperspectral reflectance and to develop a new optical model (OPTRAM) for remote sensing of surface soil moisture; derived a new solution to Richards&rsquo; equation to improve NASA&rsquo;s AirMOSS P-band radar root zone soil moisture retrieval algorithm; developed and tested a new TDR array for measurement of near-surface soil moisture in 5-mm depth increments.</li><br /> <li><strong>University of California-Riverside (Laoshen Wu)</strong>: Developed new numerical methods to identify and apportion the source of heavy metal pollution in cropland; an adaptive Gaussian process-based method for efficient Bayesian experimental design in groundwater contaminant source identification problems; new methods for Data assimilation for unsaturated flow models with restart adaptive probabilistic collocation based Kalman filter; sequential ensemble-based optimal design for hydraulic model parameter estimation; and a mathematical model for the transfer of soil solutes to runoff under water scouring and raindrop impact.</li><br /> <li><strong>University of California-Riverside (Jirka Simunek): </strong>Continued to expand the capabilities of the HYDRUS modeling environment by developing specialized modules for more complex applications that cannot be solved using its standard versions, including: furrow fertigation, drip irrigated gray and desalinated water, deficit irrigation; investigated accuracy of machine learning models, Hydrological applications included: recharge into layered loess, stony soil, green roofs, permeable pavements and preferential flow through glacial deposits; fate of carbon nanotube.</li><br /> <li><strong>University of Delaware (Yan Jin): </strong>Developed method of using size-dependent turbidimetric correlations to quantify colloids in different size fractions, i.e. 0.1-0.45 and 0.45-1.0 &micro;m; Quantified the role of colloids in organic carbon (OC) retention and mobilization in agricultural, forestry, wetland and estuary systems; Improved understanding of redox oscillation on mineral organic association (MOAs) and carried out molecular characterization of organic matter (OM) in different size fractions; Quantified the fate and transport of a promising phosphorus (P) nanofertilizer-hydroxyapatite nanoparticle (HANP) in the co-presence of iron oxide colloids (goethite and hematite) under environmentally relevant conditions; Demonstrated the usefulness of measuring phosphate oxygen isotope fractionation of engineered phosphate-based nanoparticles (NPs) in assessing their physical transport and chemical dissolution processes; Measured effects of plant-growth-promoting-rhizobacteria (PGPR) on water evaporation and retention in soils.</li><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Developed a heat pulse probe method to estimate water content and bulk density simultaneously; a new de Vries-based thermal conductivity model for unfrozen and frozen soils that provides accurate and consistent thermal conductivity estimates, and performs better than other de Vries-based models; an improved, automated algorithm for analyzing waveforms of short TDR probes; designed and tested a water vapor diode to accumulate water naturally in specific soil layers.</li><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Established and improved a spatio-temporal wireless soil moisture monitoring network in a farmer&rsquo;s field; Provided advice to farmer about site-specific irrigation rate; Provided advice to engineering company to avoid over-irrigation in Arkansas; introduce simple check-book method and FAO-Penman ET0; introduce soil-specific irrigation management scheme; and, EC-based clay mapping. In progress: Delineation of management zones; and improving soil physical parameter estimation for field soil water processes.</li><br /> <li><strong>North Dakota State University (Aaron Daigh)</strong>: Improvement in brine spill site assessment methods and conservation equations to facilitate rapid and accurate assessment of brine spill sites; developed a new in situ remediation method to enable remediation specialist to remove 29 to 57% of brine salts from the soil surface within a few days; Evaluated salt and water transport properties in saline-sodic soil conditions for a range of soils prone to shrink-swell.</li><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: Demonstrated impact on chile pepper production and soil quality from irrigation with brackish groundwater, desalinated bracking groundwater and desalination concentrate, in support of national food security mission. Demonstrated use of zeolite to wick water from shallow groundwater to support natural native vegetation.</li><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Advances in scientific knowledge on estimating drainage rates from the root zone using long-term in situ soil moisture data.</li><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Developed conceptual model for the development and maintenance micro-aggregation on sandy soil, impacting irrigation methods; conceptual model for vapor sieve as a water reserve measure in semi-arid climates. In progress; experiments to quantify the partitioning of soil water into biological and capillary pools; hydro-geochemical evolution of karst microfractures; determination of feasibility of solarization for soil disinfection in Pacific Northwest.</li><br /> <li><strong>USDA-Bushland (Robert Schwartz and Steven Evett)</strong>: Characterized capability of failure modes of a prototype down-hole NMR device used to measure soil water content; compared deep percolation losses of drip irrigation and optimized sprinkler irrigation; developed and evaluated a frequency domain through transmission probe for soil water content sensing in conjunction with a VNA.</li><br /> <li><strong>USDA-USSL (Todd Skaggs, Scott Bradford, Ray Anderson, Elia Scudiero)</strong>: Developed new software to aid researchers investigating water and carbon fluxes in agroecosystems; new method for irrigation scheduling based on crop coefficients and eddy covariance flux partitioning; new findings concerning whether aerobic spores are a suitable surrogate for Cryptosporidium oocysts in groundwater; new overland flow and transport model.</li><br /> <li><strong>Utah State University (Scott Jones)</strong>: Developed and tested a new TDR array that allows measurement of near-surface soil moisture in 5-mm depth increments in (collaboration with UAZ); Derived a new solution to Richards&rsquo; equation to improve NASA&rsquo;s AirMOSS P-band radar root zone soil moisture retrieval algorithm (collaboration with UAZ, USC); develop a new optical model (OPTRAM) for remote sensing of surface soil moisture and vegetated soil profiles (Collaboration with UAZ); developed a new time efficient method to determine the SWC from hyperspectral reflectance via controlled laboratory experiments and inverse modeling (collaboration with UAZ).</li><br /> <li><strong>Washington State University (Markus Flury)</strong>: Demonstrated that compost can leach excess nitrate, phosphorus, and copper from bioretention soil mixes; showed that moving air-water interfaces can translocate polyaromatic hydrocarbons from porous media; showed that biodegradable plastic mulches degrade under composting conditions; demonstrated that water activities in the driest localities on earth are sufficient to support microbial life; showed that nanoparticles behave differently than micrometer-sized colloids at the air-water interface; and provided new insights on transport of non-spherical colloids; dynamics and quantity of leaching nutrients and metals from bioretention systems (compost); as well as how surface coal mining impacts soil hydraulic properties and erosion.</li><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: Completed a seismic survey at an experimental hillslope; A second snow lysimeter was installed at an experimental hillslope; The SNOWPACK model was calibrated to simulate snow pack dynamics at an experimental hillslope; An inverse modeling procedure was developed to estimate subsurface hydraulic parameters using time-lapse electrical resistivity tomography data; and the integrated watershed model GEOtop was tested in watersheds in Wyoming and Idaho.</li><br /> <li><strong> Outputs</strong></li><br /> <li><strong>University of Arizona (Marcel Shaap)</strong>: We published 3 journal articles and 2 abstracts. Schaap also wrote 7 chapters in a forthcoming &ldquo;Topics in Environmental Physics.&rdquo; Draft versions of these chapters are already used in the ENVS420/520 course &ldquo;Environmental Physics.&rdquo;</li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Research results were disseminated in collaboration with various involved groups through 6 peer-refereed international journal publications and 14 conference contributions.</li><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: Research findings were disseminated via 20 refereed journal publications, 22 conference proceedings, and a number of presentations at national and international meetings (see the publication section below). HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects.</li><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: Research results were disseminated through 10 peer-refereed international journal publications, 2 MS theses, 2 abstracts, presentations and classroom teaching.</li><br /> <li><strong>University of Delaware (Yan Jin)</strong>: Research results were disseminated in collaboration with various involved groups through 6 peer-refereed international journal publications, 1 Ph.D. dissertation, and 6 conference contributions.</li><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Research results were disseminated in collaboration with various involved groups through at least 12 peer-refereed publications.</li><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Research findings were disseminated through journal publications, Thesis, conference proceedings, presentations at national and international conferences, field days, and coordination of a 4-state research project and development of a smart-phone app for irrigation control.</li><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: Eight peer-reviewed manuscripts were published; three invited talks in China, and presentations at national meeting.</li><br /> <li><strong>North Dakota State University (Aaron Daigh)</strong>: 6 publications in peer-reviewed journals, 18 conference abstracts and 1 thesis.</li><br /> <li><strong>University of Oklahoma (Tyson Ochsher)</strong>: Maps of annual and long-term average drainage rates across the state of Oklahoma available online at <a href="http://soilmoisture.okstate.edu/html/drainage-map.html">http://soilmoisture.okstate.edu/html/drainage-map.html</a>. Manuscript under review describing and evaluating the new method for estimating drainage from in situ soil moisture data.</li><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Peer-reviewed manuscript that quantified gas fluxes across soil surface; conference contribution presenting proof for the existence of films on smooth surfaces of glass beads during drainage, specifically films of thickness that are below the current resolution threshold of CT scan images.</li><br /> <li><strong>USDA-Bushland (Robert Schwartz; Steven Evett)</strong>: CRADA partner introduced two new soil water sensors based on true, directly connected TDR, the model TDR-315L (low power, CMOS circuitry) and the model TDR-310S (round with should to fit into PVC pipe for installation into bore holes of indeterminate length, vertically, horizontally or at an angle); 1 Patent: O&rsquo;Shaughnessy, S.A., S.R. Evett, M.A. Hebel and P.D. Colaizzi. Multi-Band Photodiode Sensor. US Patent No. 9,451,745 B1. Issued Sept. 27, 2016. 11 peer reviewed journals, 2 proceedings full papers, 1 MS thesis, 14 invited and volunteered presentations.</li><br /> <li><strong>USDA-USSL (Todd Skaggs, Scott Bradford, Ray Anderson, Elia Scudiero)</strong>: Research findings disseminated via refereed journal publications, conference proceedings, and presentations at national and international meetings. Collaborative research is ongoing with researchers in Australia, Austria, Korea, Germany, Iraq, Sweden, and Taiwan.</li><br /> <li><strong>Utah State University (Scott Jones)</strong>: Research results were disseminated in collaboration with colleagues in the US and China through 5 peer-refereed international journal publications and 17 conference or invited talk contributions</li><br /> <li><strong>Washington State University (Markus Flury)</strong>: Published 10 peer-reviewed manuscripts and presented the research results in national and international conferences (Soil Science Society Annual Meeting, Phoenix, AZ; European Geoscience Union, Vienna, Austria), and invited talks in China and Germany.</li><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: 5 peer-reviewed manuscripts and 4 conference abstracts, 4 courses were taught: Soil physics lecture (3 credits), Soil physics laboratory (2 credits), Agroecology capstone (1.5 credits), and Modeling flow and transport (4 credits).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong> Activities</strong></li><br /> <li><strong>University of Arizona (Marcel Schaap)</strong>: (1) Developed new strategy for optimizing PTFs (pedo transfer functions) that demonstrated that while alpha-stable distributions provide a more consistent description of the estimated distributions than normal distributions, it is with modest improvement over normal distribution. The new PTFs (as well as those published by Schaap et al. 2001) will be distributed in the form of open-source python code. (2) Developed new strategy for low-parameter count PTF-assisted inversion of large heterogeneous 1D/2D/3D vadose zone domains. (3) Long-term (65 year) simulations of vadose zone moisture for drought-monitoring in the Desert-Southwest based on daily input of meteorological data for four characteristic locations with high-quality meteorological data (Tucson, El Paso, Albuquerque, and Winslow). (4) Development of lattice-Boltzmann computer code with physics-based colloid module., to establish a pore-scale model that can deal with a wide variety of colloid properties (size, charge, hydrophobicity). (5) Synthesis of Artificial Porous Media (see Tuller report). Schaap assisted the Tuller group in conducting very large-scale Lattice-Boltzmann simulations (100 million fluid voxels). (6) Currently writing a textbook for upper-level undergraduates and graduate students in the Earth and Environmental Sciences. The book is entitled &ldquo;Topics in Environmental Physics&rdquo; and contains several &ldquo;threads&rdquo; such as energy and water flow at global and local scales. Basic physical relations are presented in environmentally relevant contexts such as global change, critical zone science, drought, and pollution science.</li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: (1) <em>X-Ray Computed Tomography (CT), Synthesis of artificial porous media: </em>Refined a physical framework to generate artificial porous materials with precisely known phase distributions to test and improve previously developed 3D multiphase segmentation algorithms for X-Ray CT data. Currently publishing results and are testing the newly developed codes to make them available to the research community. (2) <em>X-Ray Computed Tomography (CT), </em><em>Surface Area Estimation from Segmented X-Ray CT Data</em>: Developed a new surface area estimator that is based on surface curvedness computed from principal curvatures. Currently publishing results and are validating the new approach for a number of CT datasets. (2) <em>Remote Sensing of Soil Moisture: </em>In collaboration with Utah State University we are developing novel measurement and remote sensing techniques for characterization of near surface soil moisture with the following outcomes. (a) <em>Advancing NASA&rsquo;s AirMOSS P-Band Radar Root Zone Soil Moisture Retrieval Algorithm via Incorporation of Richards&rsquo; Equation</em> by deriving a more realistic, physically-based SMP model containing three free parameters based on a solution to Richards&rsquo; equation for unsaturated flow in soils. (b) <em>A Novel Approach to Remote Sensing of Soil Moisture Applied to Sentinel-2 and Landsat-8 Observations</em> that overcomes a number of restrictions of present models and provides equivalent accuracy. (c) <em>TDR Array Probe for Monitoring Near-surface Soil Moisture Distribution</em> in collaboration with Utah State University. See report from Utah State University. (d) <em>Soil Water content from Hyperspectral data</em>: Developing a new time efficient method to determine the Darcy-scale SWC from hyperspectral reflectance via controlled laboratory experiments and inverse modeling that will lead to high-resolution mapping of Darcy-scale surface moisture redistribution processes with the potential for rapid estimation of soil hydraulic properties. (3) <em>A New Method to Estimate CEC from Water Vapor Sorption Isotherms<strong>: </strong></em>Based on measurements for more than 200 soils of various textures we developed a new approach to estimate CEC from water vapor isotherms considering hysteresis with superior results compared to models/methodologies based on other soil properties. Knowledge of soil cation exchange capacity (CEC) is crucial for soil fertility considerations, sorption and release of polar and non-polar compounds, engineering applications, and other biogeochemical processes.</li><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: In 2016 we offered short (three-day) courses on how to use HYDRUS models at a) Colorado School of Mines, Golden, CO, b) Czech University of Life Sciences, Prague, Czech Republic, and c) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China. About 100 students participated in these short courses.</li><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: Taught hydrology course. Presentations to various academic and non-academic groups. Converted the PCbased WatSuit, a steady-state model to assess irrigation water quality and soil response, to a web-based version. Developed a salinity management website. Received funds for three projects to support my research.</li><br /> <li><strong>University of Delaware (Yan Jin)</strong>: (1) We developed a simple and reliable method for quantification of colloids using correlations between nephelometric turbidity and mass concentrations of colloids, that for the first time, permits quantification of &lt; 1.0 &micro;m colloids in different size fractions in environmental samples, especially colloids &lt; 0.45 &micro;m, which are traditionally considered as dissolved solutes and hence underestimated. (2) Investigated colloids and colloidal OC in different size fractions from samples collected from agricultural, forestry, wetland, and estuary systems. (3) Explored the biogeochemical role of colloids in redox dynamic systems (such as the wetlands). (4) Examined the cotransport and retention of HANPs and iron oxide colloids (goethite and hematite) in water-saturated sand columns under environmentally relevant transport conditions (pH, ionic strength, and natural OM type and concentration, and flow rate). Findings offer important insights into application of HANPs as P nanofertilizer and an <em>in situ</em> amendment for the remediation of contaminated sites where iron oxides are present ubiquitously. (5) Investigated how low-molecular-weight organic acids (LMWOAs) secreted by plants in agricultural soils mediate the dissolution of HANPs and release of dissolved PO₄^3&minus;. Our results provide useful insights into understanding the dissolution kinetics and oxygen isotopic evolution of phosphate-based NPs that are relevant to plant&ndash;soil systems particularly at the rhizosphere. (6) Water is a key resource limiting agricultural production; the limitations will further intensify as agricultural activities expand to less fertile areas in order to meet the world&rsquo;s growing demands for food and fiber. In support of enhancing plant drought stress tolerance by plant growth promoting rhizobacteria (PGPR) we are investigating PGPR&rsquo;s role in mediating physiochemical and hydrological changes in the rhizospheric soil that may impact plant drought stress tolerance. (7) We continued our collaboration with colleagues Dr. Jie Zhuang (Institute of Applied Ecology, Shengyang, of the Chinese Academy of Sciences and University of Tennessee) and Dr. Chongyang Shen (China Agricultural University, Beijing) on colloid fate and transport.</li><br /> <li><strong>Iowa State University (Robert Horton)</strong>: (1) Developed a method to simultaneously determine soil bulk density and volumetric water content, _b and  from soil thermal properties measured with a heat pulse sensor. (2) Developed a simplified de Vries-based model to estimate thermal conductivity of unfrozen and frozen soil. (3) Adaptive waveform interpretation with Gaussian filtering (AWIGF) and second order bounded mean oscillation operator are TDR analysis methods based on second order differentiation. We are theoretically and experimentally evaluating the performance of AWIGF and &nbsp;on both long and short probes. (4) Diurnal soil temperature fluctuations drive subsurface cyclic water vapor fluxes. We are investigating the concept of a water diode to maintain direction-controlled vapor fluxes, and water vapor diodes can be used to accumulate or remove water in particular soil layers.</li><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Continue investigation of the spatial variability of soil hydraulic properties. Installed a wireless soil water monitoring network in farmer&rsquo;s field. Determined that EC is a very effective auxiliary variable to estimate the spatial variability of soil clay content at the field scale. Submission of CAP grant in collaboration with 5 investigators and three farms. Begun to use the Root Zone Water Quality Model to simulate soil water dynamics, crop growth and greenhouse gas emissions. Working on decision support for irrigation water management. In collaboration with visiting international scientists, progress was made on the derivation of field capacity for Kentuckian soils (published in SSSAJ), impact of stones on hydraulic properties, new concepts on the derivation of soil quality based on soil physical measurements (SSSJA). Participation in College Strategic Team, mentoring of 5 graduate students, taught 2 courses: Spatial and Temporal Statistics, and Soil Use and Water Management. Active in a number of Extension and Outreach activities.</li><br /> <li><strong>New Mexico State University (Shukla Manoj)</strong>: Taught soil physics, advanced soil physics and environmental soil science classes. Hosted three faculty members from University of Hebei, China. Field and greenhouse trips were organized to collect soil and water samples, soil moisture content, soil temperature, and other meteorological data. Experiments were planned on use of brackish groundwater and RO concentrate for looking at influence of irrigation water salinity on soil microbiological properties. Soil and plant samples were collected from Pecan orchards from Hatch, NM up to Fabens, Texas to evaluate salinity induced changes in pecan physiology. Proposals were written and submitted to various Funding agencies. Indaziflam movement through preferential flow channels was evaluated and its impact on Pecan growth and gas exchange parameters, and soil properties were evaluated. Work was started on developing a device to remotely collect soil moisture content data by commercially available sensors.</li><br /> <li><strong>North Dakota State University (Aaron Daigh)</strong>: (1) Continue development of a new method to harvest brine spill salts from the soil surface with no mechanical disturbance needed for brine spill remediation purposes. The use of a crystallization inhibitor was surface applied resulting in salt dendrites to form above the soil surface during evaporation. The method was field tested at three brine evaporation pits in northern North Dakota along wide traditional in-situ remediation methods. (2) Large soil leaching columns were constructed to monitor brine leachate over time. were constructed. (3) Ongoing field experiment monitoring soil temperature, water content and thermal properties to improve our understanding of soil heat and water processes across spatial scales leading to development of a suite of methodologies to design and execute a &lsquo;soil weather&rsquo; forecasting system.</li><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Evaluated a method for estimating drainage rates from the root zone using long-term in situ soil moisture data, and the relationship between those drainage estimates and long-term groundwater recharge rates. Calibrated a hydrologic model, Hydrus-1D, using measured meteorological data and soil moisture data from four Oklahoma Mesonet sites, and we used the calibrated model to provide independent estimates of drainage for comparison with our new method. We wrote and submitted a manuscript describing the results of this project.</li><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Initiated investigation of soil water relations in sandy agricultural soil to improve irrigation efficiency and effectiveness. Continued field and laboratory investigations associated with the evolutionary development of micro-aggregation in sandy soil. Continue investigation of biophysical mechanisms associated with the evolution of water repellency to uncover a remediation strategy. Initiated laboratory experiments to investigate the erosional evolution of microfractures in the epikarst. Completed first year field trials to determine the efficacy of using soil solarization for pest and weed disinfection in the Pacific Northwest. Continue international collaboration to identify and quantify mechanisms that drive gas exchange across the interface between vadose zone and atmosphere. Collaboration to understand the role of thin films in the redistribution of oil-water flow in porous media. Manuscript development on a number of these projects. Cranberry growers traditionally use an established matric potential range to maximize productivity. Because of the strong hysteresis exhibited by cranberry sands, we are exploring soil moisture as a more accurate control to maximize productivity.</li><br /> <li><strong>USDA-Bushland (Robert Schwartz and Steven Evett)</strong>: (1) We continued work with commercial and university partners related to a Materials Transfer Research Agreement to develop and test an NMR based down-hole device for determining soil water content. (2) We continued work with a Cooperative Research and Development Agreement partner to develop new, low-cost soil water and bulk electrical conductivity sensors based on miniaturized TDR circuitry that is directly coupled to the probe waveguide. (3) We continued work with US and Chinese partners on the Water Saving Technologies Flagship Project of the USDA-China Ministry of Science and Technology joint Science and Technology Agreement, which was renewed in 2016. (4) We continued development of sensors, sensing systems, software and hardware systems and systems integration for scheduling and control of variable rate irrigation systems. (5) We completed work with an M.S. student on comparison of deep percolation losses in cropped fields irrigated using mid elevation spray application sprinkler as compared with subsurface drip irrigation. (6) We continued long-term work comparing ET by field soil water balance to ET by weighing lysimeter. (7) We began work on relating soil available water fraction to water stress indices with the goal of developing a model to transform maps of crop water stress index (or another stress index) into maps of root zone available soil water.</li><br /> <li><strong>USDA-USSL (Todd Skaggs, Scott Bradford, Ray Anderson, Elia Scudiero)</strong>: (1) Existing subsurface flow and transport models were modified to simulate these physically non-equilibrium processes by considering overland flow and transport in: (i) mobile and immobile regions; (ii) active and passive flow regions; and (iii) and active and passive flow regions with immobile water, as well as exchange between these regions.&nbsp; The developed model improves our ability to describe non-equilibrium overland flow and transport processes, and improves our understanding of factors that cause this behavior.&nbsp;(2) Explored a new method to more rapidly determine crop coefficients for novel cultivars and cultivation practices. In this study, we partition eddy covariance ET observations into evaporation (E) and transpiration (T) components using correlation structure analysis of high frequency (10-20 Hz.) observations of carbon dioxide and water vapor (Scanlon and Sahu, 2008) at three irrigated agricultural sites. The results benefit irrigation managers, farmers, and hydrologists who rely on crop coefficients to accurately predict water demands, with a particular benefit to farmers and irrigators exploring new production systems to improve production and efficiency. (3) Investigation to compare the viability and utility of the two commonly used approaches for creating soil salinity maps. The approaches were tested using 22 fields (total 542 ha) located in California&rsquo;s western San Joaquin Valley.</li><br /> <li><strong>Utah State University (Scott Jones)</strong>: (1) Investigated the influence on soil water retention properties of stone content, which dominate forest soils. (2) Collaborated on development of a novel approach to remote sensing of soil moisture applied to Sentinel-2 and Landsat-8 observations that only requires a single universal parameterization for a given location, which is a significant advancement that opens a new avenue for remote sensing of soil moisture. (3) A TDR array was designed to provide cm-resolution measurements of soil moisture content from the surface downward. (4) During soil moisture redistribution experiments, we employed a benchtop hyperspectral line scan imaging system to generate high resolution surface reflectance maps of soil surface moisture from which, by inverse Hydrus-2D modeling, we determined the soil hydraulic function parameters during soil moisture redistribution experiments. Results demonstrate the potential for this method for rapid soil hydraulic properties determination. In addition, the experiments provide valuable basic knowledge that can be potentially applied for large scale airborne or satellite remote sensing of surface soil moisture. (5) We are collaborating on a project to advance NASA&rsquo;s AirMOSS P-Band radar root zone soil moisture retrieval algorithm via incorporation of Richard&rsquo;s equation.&nbsp; Evaluation of the new soil moisture profile model revealed that it exhibits greater flexibility for fitting measured and simulated SMPs than the currently applied polynomial</li><br /> <li><strong>Washington State University (Markus Flury)</strong>: Work on review article on colloid transport in unsaturated porous media. Organized a special section on ``Lysimeters in Vadose Zone Research&rdquo; in the Vadose Zone Journal. Organized symposium on &ldquo;Nanoparticle Fate and Transport in Soil and Groundwater Systems&rdquo; at the European Geoscience Union Annual meeting. Measured leaching of nitrate, phosphorus, and copper from compost-amended bioretention systems. Investigated transport mechanisms of polyaromatic hydrocarbons (fluorathene) in unsaturated porous media. Used numerical modeling to assess the effect of biodegradable plastic mulches on water dynamics in field soils. Performed field experiment to assess suitability of biodegradable plastic mulches for pumpkin production. Measured soil quality in field trials to check for adverse effects of biodegradable plastic mulches. Tested degradation of biodegradable plastic mulches under compost conditions. Conducted household-scale soil phosphorous (P) sampling and property owner surveys. Analyzed and obtained soil P data from 74 urban locations (511 samples) and seven agricultural locations (60 samples).</li><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: We continue to maintain a state-wide soil moisture network consisting of 17 sites in rangelands. We continue to maintain 3 snow-soil stations, 6 soil moisture stations, and 2 snow lysimeters in NoName watershed, WY. A collaboration was initiated with Stefano Endrizzi (University of Zurich) to better understand and debug the integrated watershed model GEOtop.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li><strong> Milestones</strong></li><br /> <li><strong>University of Arizona (Marcel Schaap)</strong>: Improved hierarchical pedotransfer function to be distributed as Rosetta3 (python source-code). PTF-assisted inversion technique published. Initial (2D) version of pore-scale colloid code developed and tested for low and high ionic strengths. Wrote seven chapters of an 11-chapter textbook. Conducted first phase of comparison of drought indices and soil moisture simulations.</li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Developed a new hybrid method based on surface curvedness to determine interfacial/surface areas from segmented X-Ray CT observations of multiphase porous systems. Developed a novel method to estimate the cation exchange capacity (CEC) of soils from water vapor sorption isotherms. Developed a new time efficient method to determine the SWC from hyperspectral reflectance via controlled laboratory experiments and inverse modeling. Developed a new optical model (OPTRAM) for remote sensing of surface soil moisture. Derived a new solution to Richards&rsquo; equation to improve NASA&rsquo;s AirMOSS P-band radar root zone soil moisture retrieval algorithm. Develop and tested a new TDR array that allows measurement of near-surface soil moisture in 5-mm depth increments. Refined a physical framework to generate artificial porous materials with precisely known phase distributions to test and improve previously developed 3D multiphase segmentation algorithms for X-Ray CT data.</li><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: New options were added to Hydrus-2D modeling program: coupled movement of water, vapor and energy, surface energy balance to calculate potential evaporation, effect of slope and plant shading on solar irradiation, root growth and spatial distribution, and overland flow module. Various novel applications of the existing models were implemented; publication of two review papers.</li><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: (1) Source identification and apportionment of soil cadmium in cropland, one of the most toxic heavy metals in the environment, is being performed in grower&rsquo;s fields in China. (2) Development of an adaptive Gaussian process-based method for efficient Bayesian experimental design in groundwater contaminant source identification problems. (3) Motivated by recent developments in uncertainty quantification and ensemble Kalman filter (EnKF), we proposed and investigated a restart adaptive probabilistic collocation based Kalman filter (RAPCKF) for data assimilation in unsaturated flow problems. RAPCKF was demonstrated to be more efficient than EnKF with the same computational cost. (4) Investigated Sequential ensemble-based optimal design for parameter Estimation. (5) Developed a mathematical model to quantify the transfer of soil solutes to runoff under water scouring.</li><br /> <li><strong>University of Delaware (Yan Jin)</strong>: (1) Turbidity-concentration correlations were developed from a large number of soils samples to be used as a quick and reliable method that allows quantification of colloids in different size fractions. The ability to quantify colloids in the &lt; 0.45 &micro;m fraction, which has traditionally been considered as part of the dissolved phase, in environmental samples provides the means to more accurately account for colloidal loads in natural and environmental systems. (2) We quantified the contributions of colloids and colloidal OC in various terrestrial or aquatic systems, which have important implications in differentiating OC in colloidal, nano-size and dissolved phase and thus accurately estimating the carbon inventory in different natural environments. (3) We observed that the nano size fraction (2.3-100 nm) contained the highest percentage and the most recalcitrant forms of OC compared to larger size fractions (e.g., 100-450 and 450-1000 nm) as well as had different mineral compositions. (4) We demonstrated, for the first time, that oxygen isotopic fractionation of manufactured phosphate-based NPs is insignificant during physical transport and chemical dissolution, which is useful for better understanding of the fate, transport, and transformation of engineered P-NPs in the environment. (5) We used novel experimental approaches and demonstrated that PGPR can increase soil water retention and reduce evaporation from soils.</li><br /> <li><strong>Iowa State University (Robert Horton)</strong>: We developed a heat pulse probe method to determine soil water content and soil bulk density simultaneously. We developed simplified thermal conductivity models for unfrozen and frozen soils. We developed an automated algorithm for analyzing waveforms obtained from both short and long TDR probes. We used numerical analysis to show that water vapor diodes are effective at accumulating water naturally in specific soil layers.</li><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Installed wireless sensor network for soil water content monitoring in a farmer&rsquo;s field. Substantial progress in field-scale functional soil mapping for management decision support. Progress in linking remotely sensed field information to soil processes.</li><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: (Obj 1) Quantified impacts of irrigation water salinity induced changes to evapotranspiration and yields of several chile pepper variety. Threshold soil salinity range was determined beyond which yield reductions are observed in chile. Quantified impacts of irrigation water salinity induced changes to evapotranspiration and yields of several halophytes. Quantified increases in soil salinity and several cations and anions in soil with continued irrigation with brackish groundwater and RO concentrate. Showed Clinoptilolite zeolite can be used to wick water from groundwater tables within 3 m from surface to support native vegetation. Showed Clinoptilolite zeolite or soils amended with Clinoptilolite zeolite improve hydraulic properties of soils especially sand but increase nitrate leaching. Quantified dissipation rates and half-life of indaziflam herbicide. (Obj 2) Calibration equations developed for three soil moisture sensors (CS616, Hydra probe, and TM5 sensor). Work started on developing a sensor to collect data at a location and directly transmit to central storage. (Obj 3) Dissipation rates for indaziflam were quantified that would be useful for management of Pecan orchards. Ion accumulation in soil and plant was quantified that would be a helpful for designing improved irrigation strategies for using RO for agriculture</li><br /> <li><strong>North Dakota State University (Aaron Daigh)</strong>: Developed a new method to harvest brine spill salts from the soil surface without mechanical disturbance. This method has great potential to increase brine spill remediation timelines and reduce risks to the environment. Improved our understanding of soil sodicity effects on soil pore size distributions in smectite dominated soils. Evaluated the evaporation method for determining soil water retention across a gradient of salinity, sodicity, and texture for soils containing smectite clays.</li><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Manuscript describing the soil-moisture based method for estimating drainage was submitted for peer review.</li><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Developed a cohesive conceptual framework for the development, evolution and amelioration of water repellency in coarse textured media. Quantified the governing physics responsible for film based drainage along non-textured oil-water systems. Completed laboratory installation and demonstrated that film flow instability leads to 3 distinct liquid flow regimes that coexist in natural micro-fractures. Developed dynamic (rather than static) hysteresis curves for cranberry sands.</li><br /> <li><strong>USDA-Bushland (Robert Schwartz and Steven Evett)</strong>: First season of multi-location tests in semi-arid to humid climates of the integrated Irrigation Scheduling Supervisory Control and Data Acquisition (ISSCADA) system indicated positive outcomes for the system and system components. M.S. thesis was completed by student on comparison of deep percolation losses in sprinkler irrigated versus subsurface drip irrigated fields.</li><br /> <li><strong>USDA-USSL (Todd Skaggs, Scott Bradford, Ray Anderson, Elia Scudiero)</strong>: Concluded that aerobic spores can served as a conservative surrogate of the transport behavior of oocysts over a range of environmentally relevant conditions.&nbsp;Based on these findings, the US EPA is in the process of modifying regulations associated with groundwater surface water interactions to include aerobic spores. In collaboration with USDA-ARS we have developed new capabilities for regional-scale assessments of soil salinity, including: (i.) new satellite remote sensing techniques for mapping root zone salinity at regional-scales; and (ii.) new techniques for incorporating satellite-based estimates of evapotranspiration and groundwater storage changes into land surface models.</li><br /> <li><strong>Utah State University (Scott Jones)</strong>: Developed and implemented enhanced SDI-12 commands for heat pulse sensor improvement including ambient temperature correction and in situ needle spacing calibration. Submitted 3 new proposals to advance sensor development at the state and federal levels. Developed and tested a new TDR array that allows measurement of near-surface soil moisture in 5-mm depth increments. Developed a new optical model (OPTRAM) for remote sensing of surface soil moisture. Derived a new solution to Richards&rsquo; equation to improve NASA&rsquo;s AirMOSS P-band radar root zone soil moisture retrieval algorithm. Developed a new time efficient method to determine water content and water flux during imbibition from a Shortwave Infrared Camera measurement of reflectance via controlled laboratory experiments and inverse modeling.</li><br /> <li><strong>Washington State University (Markus Flury)</strong>: (Obj. 1) Developed mechanistic understanding of interactions of colloids and hydrophobic compounds at the air-water interface. Showed that hydrophobic substances, i.e., PAHs, will preferentially partition to the air-water interface during transport through porous media. Showed that currently used bioretention soil mixes containing compost leach excess nitrate, phosphorus, and copper. We determined vapor sorption isotherms to evaluate the dry-limits of life. Preliminary data analysis showed a broad range of soil P concentrations in urban and suburban residential areas in the increasingly urbanized Puyallup Watershed, South Puget Sound. (Obj. 2) We applied a numerical modeling to analyze the effects of biodegradable plastic mulches on soil moisture. (Obj. 3) We completed a second of four field seasons to evaluate the effects of biodegradable plastic mulches on soil quality.</li><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: PhD candidate Tegenu Engda successfully defended his dissertation entitled: Soil moisture-based drought monitoring in rangeland ecosystems. Three papers were published from this work. Tegenu is now employed as a postdoc at CU Boulder.</li><br /> </ol>

Publications

<p><strong>Peer-reviewed Articles</strong></p><br /> <p>&nbsp;</p><br /> <ol><br /> <li>Anapalli, S.S., L.R. Ahuja, P.H. Gowda, L. Ma, G. Marek, S. Evett and T. Howell. Simulation of crop evapotranspiration and crop coefficient in weighing lysimeters. Agric. Water Manage. 177 (2016) 274&ndash;283. http://dx.doi.org/10.1016/j.agwat.2016.08.009. 2016.</li><br /> <li>Anderson, R.G., Alfieri, J.G., Tirado-Corbala, R., Gartung, J.L., Mckee, L.G., Prueger, J.H., Wang, D., Ayars, J.E., Kustas, W.P. 2016. Assessing FAO-56 dual crop coefficients using eddy covariance flux partitioning. Agricultural Water Management. 179:92-102. doi:10.1016/j.agwat.2016.07.027. Scudiero, T. H. Skaggs, D. L. Corwin. 2015. Regional-scale soil salinity assessment using Landsat ETM+ canopy reflectance. Remote Sensing of Environment 169: 335&ndash;343, doi:10.1016/j.rse.2015.08.026.</li><br /> <li>Armindo, R.A.2, and O. Wendroth. 2016. Physical Soil Structure Evaluation based on Hydraulic Energy Functions. Soil Sci. Soc. Am. J. 80:1167&ndash;1180, doi:10.2136/sssaj2016.03.0058</li><br /> <li>Arthur, E., M. Tuller, P. Moldrup, and L.W. De Jonge, 2016. Evaluation of Theoretical and Empirical Water Vapor Sorption Isotherm Models for Soils. Water Resour. Res., 52(1):190&ndash;205, doi:10.1002/2015WR017681</li><br /> <li>Baath G. S., M. K. Shukla, P. W. Bosland, R. L. Steiner, and S. J. Walker. 2017. Irrigation Water Salinity Influences at Various Growth Stages of Capsicum annuum. Ag Water Management. 179: 246-253.</li><br /> <li>Bohrer, S.L., R. Limb, A.L. Daigh, J.M. Volk, and A.F. Wick. 2016. Fine and coarse-scale patterns of vegetation diversity on reclaimed surface coal mineland over a 40-year chronosequence. Environ. Management. Accepted.</li><br /> <li>Bradford, S. A., and S. Torkzaban.&nbsp; 2015.&nbsp; Determining parameters and mechanisms of colloid retention and release in porous media.&nbsp; Langmuir.&nbsp; 31, 12096&ndash;12105.</li><br /> <li>Bradford, S. A., H. Kim, B. Headd, and S. Torkzaban.&nbsp; 2016.&nbsp; Evaluating the transport of Bacillus subtilis spores as a potential surrogate for Cryptosporidium parvum oocysts.&nbsp; Environmental Science &amp; Technology, 50, 1295-1303.</li><br /> <li>Bradford, S.A., and R. Harvey. 2017. Future research needs involving pathogens in groundwater.&nbsp; Hydrogeology Journal, In Press.</li><br /> <li>Brunetti, G. J. &Scaron;imůnek, and P.Piro, A comprehensive analysis of the variably-saturated hydraulic behavior of a green roof in Mediterranean climate, Vadose Zone Journal, 15(9), pp. 15, doi: 10.2136/vzj2016.04.0032, 2016a.</li><br /> <li>Brunetti, G., J. &Scaron;imůnek, and P. Piro, A comprehensive numerical analysis of the hydraulic behavior of a permeable pavement, Journal of Hydrology, 540, 1146-1161, doi: 10.1016/j.jhydrol.2016.07.030, 2016b.</li><br /> <li>Chahal, M. K., Z. Shi, and M. Flury, Nutrient leaching and copper speciation in compost-amended bioretention systems, Sci. 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Siyal, The effect of different fertigation strategies and furrow surface treatments on plant water and nitrogen use, Irrigation Science, 34(1), 53-69, doi:10.1007/s00271-015-0487-z, 2016.</li><br /> <li>Sintim, H. Y., and M. Flury, Is biodegradable plastic mulch the solution to agriculture&rsquo;s plastic problem?, Environ. Sci. Technol., 50, (in press), 2016.</li><br /> <li>Slimene, E. B., L. Lassabatere, J. &Scaron;imůnek, T. Winiarski, and R. Gourdon, The role of heterogeneous lithology in a glaciofluvial deposit on unsaturated preferential flow &ndash; a numerical study, Journal of Hydrology and Hydromechanics, 65(??), ???-???, (in press).</li><br /> <li>Song, L. W.P. Kustas, S. Liu, P.D. Colaizzi, H. Nieto, Z. Xu, Y. Mae, M. Li, T. Xu, N. Agam, J.A. Tolk and S.R. Evett. Applications of a thermal-based two-source energy balance model using Priestley-Taylor approach for surface temperature partitioning under advective conditions. J. Hydrol. 540(2016):574&ndash;587. http://dx.doi.org/10.1016/j.jhydrol.2016.06.034. 2016</li><br /> <li>Thapa, R., A. Chatterjee, R. Awale, D. McGranahan, and A. Daigh. 2016. Meta-analysis on the effect of enhanced efficiency fertilizers on nitrous oxide emissions and crop yields in major cereal systems. Soil Sci. Soc. Am. J. 80:1121-1134.</li><br /> <li>Tian, Z., Y. Lu, R. Horton, and T. Ren. &nbsp; A simplified de Vries-based model to estimate thermal conductivity of unfrozen and frozen soil. Europ. J. Soil Sci. 66:1-9.&nbsp; doi: 10.1111/ejss.12366</li><br /> <li>Tolk, J.A., S.R. Evett, Wenwei Xu and R.C. Schwartz. Constraints on water use efficiency of drought tolerant maize grown in a semi-arid environment. Field Crops Res. 186:66&ndash;77. 2016.</li><br /> <li>Tong, B., Z. Gao, R. Horton, Y. Li, and L. Wang. 2016. An empirical model for estimating soil thermal conductivity from soil water content and porosity. Hydrometeor, 17, 601&ndash;613.</li><br /> <li>Tong, B., Z. Gao, R. Horton, and L. Wang. 2016. Soil apparent thermal diffusivity estimated by conduction and by conduction-convection heat transfer models. J. Hydrometeor. doi.org/10.1175/JHM-D-16-0086.1.</li><br /> <li>Torkzaban, S., and S. A. Bradford.&nbsp; 2016.&nbsp; Critical role of surface roughness on colloid retention and release in porous media.&nbsp; Water Research, 88, 274-284.</li><br /> <li>Vereecken, H., A. Schnepf, J. W. Hopmans, M. Javaux, D. Or, T. Roose, J. Vanderborght, M. Young, W. Amelung, M. Aitkenhead, S. D. Allisson, S. Assouline, P. Baveye, M. Berli, N. Bruggemann, P. Finke, M. Flury, T. Gaiser, G. Govers, T. Ghezzehei, P. Hallett, H. J. Hendricks Franssen, J. Heppel, R. Horn, J. A. Huisman, D. Jacques, F. Jonard, S. Kollet, F. Lafolie, K. Lamorski, D. Leitner, A. McBratney, B. Minasny, C. Montzka, W. Nowak, Y. Pachepsky, J. Padarian, N. Romano, K. Roth, Y. Rothfuss, E. C. Rowe, A. Schwen, J. Simunek, J. Van Dam, S. E. A. T. M. van der Zee, H. J. Vogel, J. A. Vrugt, T. Wohling, and I. M. Young, Modeling soil processes: Key challenges and new perspectives, Vadose Zone J., 15, doi:10.2136/vzj2015.09.0131, 2016.</li><br /> <li>Wang, Z., Y. Lu, Y. Kojima, S. Lu, M. Zhang, Y. Chen, and R. Horton. 2016. Tangent line/second-order bounded mean oscillation waveform analysis for short TDR probe. doi:10.2136/vzj2015.04.0054.&nbsp; Vadose Zone J. 15:1-7.</li><br /> <li>Wang Dengjun, Shen Chongyang, Jin Yan, Su Chunming, Chu Lingyang, Zhou Dongmei. 2016. Role of Solution Chemistry in the Retention and Release of Graphene Oxide Nanomaterials in Uncoated and Iron Oxide-Coated Sand. Sci. of the Total Environ. 577, xx-xx. DOI: 10.1016/j.scitotenv.2016.11.029.</li><br /> <li>Wang, D.J., Y. Xie, D. P. Jaisi, Y. Jin. 2016. Effects of low-molecular-weight organic acids on the dissolution of hydroxyapatite Nanoparticles. Environ. Sci.: Nano. 3: 768-779, DOI: 10.1039/C6EN00085A.</li><br /> <li>Wang, Z., Y. Jin, C. Shen, T. Li, Y. Huang, B. Li. 2016. Spontaneous detachment of colloids from primary energy minima by Brownian diffusion. PLOS One, 11(1), doi.org/10.1371/journal.pone.0147368</li><br /> <li>Wang, Haizhen, Jun Lou, Haiping Gu, Xiaoyan Luo, Li Yang, Laosheng Wu, Yong Liu, Jianjun Wu, and Jianming Xu. 2016. Efficient biodegradation of phenanthrene by a novel strain Massilia sp. WF1 isolated from a PAH-contaminated soil. Environ Sci Pollut Res. 23:13378-13388.</li><br /> <li>Xiao, X., T.J. Sauer, J.W. Singer, R. Horton, J.L. Heitman, and T. Ren. Partitioning evaporation and transpiration in a maize field using heat pulse sensors for evaporation measurement. Transactions of the ASABE 59:591-599.</li><br /> <li>Xu, S., J. Qi, X.J. Chen, V. Lazouskaya, J. Zhuang, and Y. Jin. 2016. Coupled effect of extended DLVO and capillary interactions on the retention and transport of colloids through unsaturated porous media. Sci. of the Total Environ. 573: 564-572.</li><br /> <li>Yan, J., V. Lazouskaya, Y. Jin. 2016. Soil colloid release and stability affected by DOM under different redox conditions. Vadose Zone J. DOI:10.2136/vzj2015.02.0026</li><br /> <li>Yang, Y.1, O. Wendroth, and R.J. Walton. 2016. Temporal dynamics and stability of spatial soil matric potential in two land use systems. Vadose Zone J. 15, doi:10.2136/vzj2015.12.0157.</li><br /> <li>Yang, Ting, Quanjiu Wang, Laosheng Wu, Pengyu Zhang, Guangxu Zhao, Yanli Liu. A mathematical model for the transfer of soil solutes to runoff under water scouring. Science of the Total Environment. 2016, 569-570: 332-341.</li><br /> <li>Yang, Ting, Quanjiu Wang, Laosheng Wu, Guangxu Zhao, Yanli Liu, Pengyu Zhang. An Approximately Semi-Analytical Model for Describing Surface Runoff of Rainwater Over Sloped Land. Water Resources Management. 2016, 30: 1-14.</li><br /> <li>Yang, Ting, Quanjiu Wang, Laosheng Wu, Guangxu Zhao, Yanli Liu and Pengyu Zhang. A mathematical model for soil solute transfer into surface runoff as influenced by rainfall detachment. Science of the Total Environment. 2016, 557-558: 590-600.</li><br /> <li>Zeng, W., C. Xu, J. Huang, J. Wu, and M. Tuller, 2016. Predicting Near-Surface Moisture Content of Saline Soils from NIR Reflectance Spectra with a Modified Gaussian Model. Soil Sci. Soc. Am. J., 80, doi:10.2136/sssaj2016.06.0188.</li><br /> <li>Zhang, M. I. Engelhardt, J. &Scaron;imůnek, S.A. Bradford, D. Kasel, A.E. Berns, H. Vereecken, and E. Klumpp, Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils, Environmental Pollution, doi: 10.1016/j.envpol.2016.12.018, 2016. (in press)</li><br /> <li>Zhang, J., W. Li, L. Zeng, and L. Wu. 2016. An adaptive Gaussian process-based method for efficient Bayesian experimental design in groundwater contaminant source identification problems, Water Resources Research. 52(8): 5971-5984.</li><br /> <li>Zhang, M, S. A. Bradford, J. &Scaron;imůnek, H. Vereecken, and E. Klumpp, Do goethite surfaces really control the transport and retention of multi-walled carbon nanotubes in chemically heterogeneous porous media? Environmental Science &amp; Technology, 543, 892-909, doi: 10.1016/j.jhydrol. 2016.11.007, 2016.</li><br /> <li>Zhang, M., S.A. Bradford, J. &Scaron;imůnek, H. Vereecken, and E. Klumpp, Roles of cation valance and exchange on the retention and colloid-facilitated transport of functionalized multi-walled carbon nanotubes in a natural soil, Water Research, 109, 358-366, doi: 10.1016/j.watres.2016.11.062, 2017.</li><br /> <li>Zhang, Y.G, Schaap, M.G., Guadagnini, A. and Neuman S.P., 2016. Inverse modeling of unsaturated flow using clusters of soil texture and pedotransfer functions. WRR, Vol 52(10),p 7631-7644. DOI: 10.1002/2016WR019016.</li><br /> <li>Zhang, Y.G., Schaap, M.G., 2016 (accepted). Weighted Recalibration of the Rosetta Pedotransfer Model with Improved Estimates of Hydraulic Parameter Distributions and Summary Statistics (Rosetta3). To be published in 2017.</li><br /> <li>Zhang, X., H. Lei, L. Zhu, M. Qian, G. Yadavalli, J. Wu, S. Chen, From plastics to jet fuel range alkanes via combined catalytic conversions, Fuel 188, 28&ndash;38, 2016.</li><br /> <li>Zhang, X., H. Lei, L. Zhu, X. Zhu, M. Qian, G. Yadavalli, J. Wu, S. Chen, Thermal behavior and kinetic study for catalytic co-pyrolysis of biomass with plastics, Bioresources 220, 233&ndash;238, 2016.</li><br /> <li>Zhang, X., H. Lei, L. Zhu, M. Qian, X. Zhu, J. Wu, S. Chen, Enhancement of jet fuel range alkanes from co-feeding of lignocellulosic biomass with plastics via tandem catalytic conversions, Appl. Energ. 173, 418&ndash;430, 2016.</li><br /> <li>Zhang, X., H. Lei, J. Wu, S. Chen, Development of a catalytically green route to produce renewable cycloalkanes for jet fuels from diverse lignocellulosic biomasses and techno-economic analysis, Catal. Sci. Technol. 6, 4210&ndash;4220, 2016. doi: 10.1039/C5CY01623A.</li><br /> <li>Zhang, X., H. Lei, J. Wu, S. Chen, M. Chandoor, Catalytic co-pyrolysis of lignocellulosic biomass with polymers: A critical review, Green. Chem. 18, 4145&ndash;4169, 2016. doi: 10.1039/C6GC00911E</li><br /> <li>Zhang, X., H. Lei, L. Zhu, X. Zhu, M. Qian, G. Yadavalli, D. Yan, J. Wu, S. Chen, Optimizing carbon efficiency of jet fuel range alkanes from cellulose co-fed with polyethylene via catalytically combined processes, Bioresour. Technol. 214, 45&ndash;54, 2016. doi: 10.1016/j.biortech.2016.04.086.</li><br /> <li>Zhang, M., S. A. Bradford, J. &Scaron;imůnek, H. Vereecken, and E. Klumpp. 2016. <a href="https://www.pc-progress.com/Documents/Jirka/Zhang_et_al_EST_2016.pdf">Do goethite surfaces really control the transport and retention of multi-walled carbon nanotubes in chemically heterogeneous porous media?</a>Environmental Science &amp; Technology, 50, 12713-12721.</li><br /> <li>Zhang, M., S. A. Bradford, J. &Scaron;imůnek, H. Vereecken, and E. Klumpp.&nbsp; 2017.&nbsp; <a href="https://www.pc-progress.com/Documents/Jirka/Zhang_et_al_WR_2017.pdf">Roles of cation valance and exchange on the retention and colloid-facilitated transport of functionalized multi-walled carbon nanotubes in a&nbsp;natural soil</a>.&nbsp; Water Research, 109, 358-366</li><br /> <li>Zhang, M., I. Engelhardt, J. &Scaron;imůnek, S. A. Bradford, D. Kasel, A. E. Berns, H. Vereecken, and E. Klumpp.&nbsp; 2017.&nbsp; Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils. Environ. Poll., 221:470-479.</li><br /> <li>Zhi, Y., P. Li, J. Shi, L. Zeng, and L. Wu. 2016. Source identification and apportionment of soil cadmium in cropland of Eastern China: a combined approach of models and geographic information system, Journal of Soils and Sediments. 16(2): 467&ndash;475.</li><br /> <li>Zhi, Y., T. Guo, J. Shi, L. Zeng, and L. Wu. 2016. Expressing lead isotopic compositions by fractional abundances for environmental source apportionment, Environmental Pollution. DOI: 10.1016/j.envpol.2016.07.024.</li><br /> <li>Zhu, Y., H. L&uuml;, R. Horton, Z. Yu, and F. Ouyang. 2016. A modified soil moisture model for two-layer soil. Groundwater DOI: 10.1111/gwat.12387.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Theses/Dissertations</strong>:</p><br /> <ol><br /> <li>Yan, J. 2016. Quantification and Characterization of Mobile Colloids: Their Potential Role in Carbon Cycling under Varying Redox Conditions. University of Delaware.</li><br /> <li>Klaustermeier, A. 2016. Brine-contaminated soils in western North Dakota: Site assessment methodology and a new in-situ remediation method. M.S. thesis North Dakota State Univ., Fargo.</li><br /> <li>Fenix, Ashley R. Field investigation of the variation of unsaturated flow under SDI and MESA irrigated cultivated fields. Submitted in Partial Fulfillment of the Requirements for the Degree Master of Science. Major Subject: Environmental Science. West Texas A&amp;M University, Canyon, Texas, December 2016.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Patents</strong></p><br /> <ol><br /> <li>O&rsquo;Shaughnessy, S.A., S.R. Evett, M.A. Hebel and P.D. Colaizzi. Multi-Band Photodiode Sensor. US Patent No. 9,451,745 B1. Issued Sept. 27, 2016.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Multimedia</strong></p><br /> <p>Maps of annual and long-term average drainage rates across the state of Oklahoma available online at <a href="http://soilmoisture.okstate.edu/html/drainage-map.html">http://soilmoisture.okstate.edu/html/drainage-map.html</a>.</p>

Impact Statements

1. 16. University of Wyoming (Thijs Kelleners): Automated sensor measurements are combined with numerical modeling to better understand water, heat, and carbon fluxes at the plot, hillslope, and watershed scales in cold regions.

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Participants

Hoori Ajami, UC Riverside; Markus Berli, DRI Las Vegas; Maria Dragila, Oregon State University; Sarah Helalia, UC Riverside; Bob Horton, Iowa State University; Yan Jin, University of Delaware; Scott Jones, Utah State University; Morteza Sadeghi, Utah State University ; Farnaz Malekjahani, Utah State University; Thijs Kelleners, University of Wyoming; Jing Liang, UC Riverside; Laura Rosales, Nevada State College; Javier Reyes, University of Kentucky; Rose Shillito, DRI Las Vegas; Jirka Simunek, UC Riverside; Jing Yan, UC Merced; Hongxing Li, UC Riverside; Wei Zhang, Michigan State University; Xi Zhang, University of Kentucky; Samuel Araya, UC Merced; Teamrat Ghezzehei, UC Merced; Yuan Luo, DRI Las Vegas; Tobi Ewing, The Climate Corporation; Thomas Harter, UC Davis; John L. Nieber, University of Minnesota; Joan Wu, Washington State University; Ahdee Zeidman, Nevada State College; Azadeh Gholoubi, Utah State University; Markus Tuller, University of Arizona; Ebrahim Babaeian, University of Arizona; Li Chen, DRI Las Vegas; Xiaojun Shen, UC Riverside; Ian Hopman, UC Davis; Jinghui Xu, Utah State University

Brief Summary of Minutes

BRIEF SUMMARY OF MINUTES OF ANNUAL MEETING

2017 Annual Meeting of the W-3188 Multi-State Research Project:
Soil, Water, and Environmental Physics across Scales

January 2-4, 2018, Desert Research Institute, Las Vegas, NV

Maria Dragila (Chair) and Hoori Ajami (Secretary).

 

January 2 2018. Chair brought the house to order at 1:30 PM.

 

Hoori Ajami (UC Riverside) presented recent updates about the development and application of a new semi-distributed modeling framework (SMART) for catchment scale hydrologic modeling. Recent funding updates from the California Energy commission and NSF INFEWS were also discussed that focus on regional scale hydrologic model developments in California.

 

Joan Wu (Washington State University) discussed recent updates to the WEPP model by incorporating nonlinear reservoir algorithms to enhance baseflow estimation, and discussed application of the WEPP model to assess the impacts of forest treatment on water balance and sediment load. Recent updates regarding the urban projects are discussed that addressed optimizing green infrastructure in urban areas and assessing soil phosphorous levels as related to land use.

 

Toby Ewing (The Climate Corporation) discussed modeling activities at the climate corporation as well as scale dependency of van Genuchten parameters to core height.

 

Thijs Kelleners (University of Wyoming) discussed measurement and modeling of water flow at the plot, hillslope, and watershed scales using data from the NoName watershed in WY. Improved parameterization of snowmelt processes in hydrologic models and application of Time-lapse-Electrical Resistivity Tomography (ERT) data for watershed modeling are discussed.

 

Jirka Simunek (UC Riverside) presented various updates and applications of the HYDRUS family of codes for hydrological modeling, fate and transport modeling and agricultural applications. Discussed new updates regarding the improved models for overland flow estimation using HYDRUS-1D and 2D. Recent papers about the application of surrogate modeling, root growth modeling and Hydrus coupling to DSSAT are discussed.

 

Meeting closed for the day at 5:00 pm

 

January 3 2018. Chair brought the house to order at 8:30 AM.

 

Bob Horton (Iowa State University) presented recent updates about measuring transient bulk density using heat pulse and thermos-TDR, and illustrated the impact of bulk density on soil water modeling; discussed application of heat pulse sensors for quantifying sensible heat and water balance. 

 

Thomas Harter (UC Davis) discussed the issue of high nitrate concentrations in groundwater in California and presented results of multiple modeling methods to characterize nitrate sources in California groundwater using long term data records.

 

John Nieber (University of Minnesota) presented research activities related to W3188 including watershed scale hydrologic modeling, modeling subsurface erosion and evaluation of BMPs for reducing agricultural chemical inputs to surface flow. Presented development of a simplified watershed model based on the storage-discharge functions.

 

Steve Loring (W-3188 Administrative Advisor, NMSU) joined via Skype and discussed the need to identify and emphasize the impact of our scientific activities as part of the W3188 project. In addition, requirements and the timeline for submitting a renewal proposal in 2019 were discussed. The 2019 proposal needs to be submitted by the end of January 2019. 

 

Business meeting (led by Maria Dragila)

 

1. The chair discussed the group leadership and organization as well as expectations from the group members. Group members should submit their annual report to NIMSS as well as to the secretary (Hoori Ajami) to compile and submit a final report to Steve Loring by the end of January.

 

2. The members who were present unanimously selected Wei Zhang to be the secretary of the project for 2018. Wei joined the group last year and is an Assistant Professor at Michigan State University.

 

3. Location of the next year meeting is discussed and it was decided to hold the meeting in Riverside either before or after the SSSA meeting in San Diego. A Doodle poll was set-up by the Chair after the 2018 meeting to ask for the member preferences by January 15^th regarding the dates for the next meeting. Based on the poll outcome, the next year’s meeting will be held in the USDA Salinity Lab in Riverside in January 10-11, 2019.  

 

4. It was decided to invite NIFA representative to give a seminar in the next year W3188 meeting at Riverside.

 

5. Ideas for the next year proposal were discussed and groups of 4-5 members were formed to discuss emergent issues in soil science including application of remote sensing technology in soil physics, current issues related to food security and incorporating biophysical processes. A team of 6 members led by John Nieber will work on the proposal with the help of following group members: Wei Zhang (Michigan State University), Scott Jones (Utah State University), Markus Tuller (University of Arizona), Jie (Joe) Zhuang (University of Tennessee) and Ian Hopman (UC Davis).

 

6. Group photograph was taken

             https://www.dropbox.com/s/gbdcg6dftj30awm/IMG_7726.JPG?dl=0

 

Jie (Joe) Zhuang (University of Tennessee) discussed the impact of soil organic matter on pore system including pore size, porosity and connectivity. Quantitative approaches for SOM-water relation were discussed.

 Markus Berli (Desert Research Institute) presented soil moisture and flux data measurements from the SEPHAS weighting lysimeters and compared the measurements with numerical simulation results from HYDRUS-1D. The results of this work is published in a Special issue of Vadose Zone Journal, Lysimeters in Vadose Zone Research.

 

Rose Shillito (Desert Research Institute) presented a new physically based approach for quantifying the impact of water repellency on infiltration by developing a new sorptivity equation. This method will improve understanding and prediction of post-fire runoff and erosion. 

 

Yan Jin (University Delaware) discussed quantification and characterization of colloid and colloidal organic carbon concentrations. In addition, the role of plant growth promoting rhizobacteria in increasing water retention were presented.

 

Markus Tuller (University of Arizona) presented the use of variety of remote sensing products for soil moisture estimation including development of a novel approach using Sentinel and landsat observations to estimate soil moisture; utilizing data from the Maricopa TERRA-REF phenotyping scanner to quantify evapotranspiration; estimating soil properties from water vapor sorption isotherms; and modifying the ParSWMS model to accommodate nonlinear solute adsorption and to support multi-species solute simulations.

 

Morteza Sadeghi (Utah State University) presented the impact of particle size on surface reflectance and discussed development of a new analytical solution for quantifying surface reflectance and comparing the results with experimental data. In addition, brief overview of other publications related to soil moisture estimation was discussed.

 

Ebrahim Babeian (Postdoc- University of Arizona) from Markus Tuller group discussed the use of cosmic ray soil moisture observing system for validating a new remotely sensed soil moisture product using optical remote sensing data.

 

Azadeh Gholoubi (PhD student - Utah State University) discussed development of a new proximal sensing index for quantifying soil aggregate stability. 

 

Scott Jones (Utah State University) discussed the use of TDR array for near-surface soil moisture monitoring; presented recent updates about soil heat flux density sensor, and recent efforts for soil moisture monitoring and forecasting for water resource management in Utah

 

 

January 4 2018. Chair brought the house to order at 8:30 AM.

 

Javier Reyes (PhD student -University of Kentucky) from Ole Wendroth group presented the use of cluster analysis to incorporate spatial and temporal variability of soil and crop processes for delineating the irrigation management zones.

 

Xi Zhang (PhD student - University of Kentucky) from Ole Wendroth group discussed characterization of the spatial pattern of wet-range hydraulic conductivity at field scale by co-regionalization analysis. Results showed that including the electrical conductivity data in the cokriging analysis can improve prediction of spatial variability of hydraulic conductivity at a field scale.

 

Jing Yan (Post-doc UC Merced) from Teamrat Ghezzehei group discussed his recent experimental set-up to explore the impacts of spatial and temporal variability of water and nutrients on plant water uptake. Results indicated that plants are able to utilize resources from spatially segregated zones.

 

Samuel Araya (PhD student - UC Merced) from Teamrat Ghezzehei group discussed the use of machine learning methods to identify the most important soil structural variables for predicting saturated hydraulic conductivity. The new pedo-transfer function has improved hydraulic conductivity predictions compared to the ROSETTA3 model.

 

Laura Rosales-Lagarde (Nevada State College) performed analysis of sensors measuring soil temperature and volumetric water content in the SEPHAS lysimeters to identify redundant sensors and use these data for student training. 

 

Wei Zhang (Michigan State University) discussed the issue of antibiotic resistance and pathways of pharmaceuticals into vegetables; discussed the upcoming special section in the Vadose Zone Journal for advancing soil physics for securing food, water, soil and ecosystem services.

 

Meeting closed at 12:00 pm

Accomplishments

<ol><br /> <li><strong> Short-term Outcomes</strong></li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Modified the ParSWMS parallelized code for solving 3-D water and solute transport in order to accommodate nonlinear solute adsorption and to support multi-species solute simulations for optimization of soilless greenhouse substrates; Developed a method for semi-automated multiphase segmentation of 4-D Micro-Computed Tomography (mCT) data of porous media and refined a physical framework for generation of artificial porous materials with precisely known phase distributions to test and improve segmentation algorithms; Initiated field experiments with a one-of-a-kind robotic phenotyping scanner to develop physical relationships between SWIR reflectance and actual evapotranspiration in collaboration with Utah State University (Morteza Sadeghi and Scott Jones); Refined predictive capabilities for soil specific surface area based on the Guggenheim&ndash;Anderson&ndash;Boer sorption model in collaboration with Aarhus University (Emmanuel Arthur); Collaborated with Utah State University (Morteza Sadeghi and Scott Jones) to develop a new analytical radiative transfer model to explain effects of particle size on SWIR soil surface reflectance; Collaborated with Utah State University (Morteza Sadeghi, Azadeh Gholoubi, and Scott Jones) to develop new methods to measure soil aggregate stability with SWIR imaging.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong>University of California-Davis (Thomas Harter):</strong> Collaborated with California Department of Water Resources to initiate a project that reviews research knowledge and gaps on the performance of well seals in the unsaturated zone; Began collaboration with the California State Water Board to assess modeling tools for evaluation of the assimilative capacity in groundwater basins with respect to salts and nitrate; Continued work with California North Coast Regional Water Board and Siskiyou County to develop modeling tool that will support local farming community. The modeling tool is designed to develop future groundwater management tools that address important threats to groundwater dependent ecosystems; Began collaboration with the California Almond Board and a grower-cooperator to establish a long-term nutrient, soil, and groundwater monitoring site to evaluate nitrogen fluxes in an almond orchard and their response to improved irrigation and nutrient management. Almonds are now one of the dominant crops in California and have high nitrogen input requirements; Met with key stakeholder groups in the San Joaquin Valley to develop future scenarios for agriculture and urban area groundwater management and landuse under new groundwater regulations.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong>University of California-Riverside (Hoori Ajami):</strong> Extended the functionality of the semi-distributed hydrologic model (SMART) to the catchment scale; Implementing and evaluating SMART catchment scale simulations across catchments in USA and Australia in collaboration with University of New South Wales (Ashish Sharma); Developed a new approach for mapping sub-basin scale soil moisture to fine resolution using statistical methods; Developed a new ecohydrologic catchment classification framework; Developed new approaches for quantifying uncertainty in conceptual ecohydrologic models in collaboration with University of New South Wales (Lucy Marshall).</li><br /> <li><strong>University of California-Riverside (Jirka Simunek): </strong>Continued to expand the capabilities of the HYDRUS modeling environment by developing specialized modules for more complex applications that cannot be solved using its standard versions, including: developing robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches; Developing microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities. A range of applications published in 2017 include <em>Hydrological Applications</em>, <em>Fate and Transport of Various Substances (Carbon Nanotubes, Viruses, Explosives)</em>, and the <em>Use of Hydrus Models to Evaluate Various Irrigation and Fertigation Problems - Agricultural Applications. </em></li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="5"><br /> <li><strong>University of California-Riverside (Laoshen Wu)</strong>: Applied synchrotron-based X-ray microcomputed tomography and high-performance pore-scale simulations to evaluate hydraulic properties of biocharamended soil aggregates; Developed efficient evaluation of small failure probability in high-dimensional groundwater contaminant transport modeling via a two-stage Monte Carlo method; Implemented a probabilistic collocation based iterative Kalman filter for landfill data assimilation; Implemented an ANOVA-based transformed probabilistic collocation method for Bayesian data-worth analysis.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="6"><br /> <li><strong>University of Delaware (Yan Jin): </strong>Measured effects of plant-growth-promoting-rhizobacteria (PGPR) on water evaporation and retention in soils; Demonstrated the competition for retention sites when two viruses co-existed, resulting in increased transport of both viruses; Examined how the concentration of attached colloids (denoted as CAC) affect additional colloid attachment and subsequent detachment from collector surfaces; Generated data on the behavior of graphene oxide nanomaterials (GONMs), which have novel properties useful for medial and environmental applications, and in porous media under various environmentally-relevant conditions.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="7"><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Determined that a heat pulse sensor can accurately measure surface and subsurface soil heat fluxes; Developed a heat pulse probe method to estimate water content and bulk density simultaneously; Developed a method that can use a measured water retention curve (WRC) at one bulk density to estimate WRCs at other bulk density values; Developed a thermos-TDR method for estimating soil ice contents; Confirmed that soil heat pulse sensors can accurately measure daily soil water evaporation.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="8"><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Developed EC-based clay mapping based on 1 soil sample per 2 ha and EC map taken in spring; Provided advice to farmers about site-specific irrigation rate; Delineated management zones in the field; Evaluated the existing pedo-transfer functions for site-specific parameter estimation, management applications and model input; Improving soil physical parameter estimation for field soil water processes is in progress.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="9"><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: Demonstrated that irrigation with brackish groundwater and desalinated concentrate decrease chile pepper yields; Demonstrated that desalinated brackish groundwater and RO concentrate can be used to grow halophytes; Demonstrated that RO irrigation will increase soil salinity, and RO irrigation should only be applied until vegetation establishment and in non-agriculture areas; Demonstrated that zeolite can be used to wick water from shallow groundwater table located within 3 m from soil surface to support natural native vegetation especially those with rooting depth of about 60 cm or more; Disseminated research results to stakeholders.&nbsp;</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="10"><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Made progress in advancing scientific knowledge for estimating drainage rates from the root zone using long-term in situ soil moisture data.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="11"><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Obtained grower consent and finalized location selection for installation of soil moisture instrumentation in agricultural fields to assess irrigation efficiency; Commenced scientific examination of field data associated with irrigation efficiency; Began discussions with potential co-PIs for a project on deep drainage nitrate transport from sandy-soil agricultural fields; Completion of data collection for experiments on geochemical erosion of carbonate rock.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="12"><br /> <li><strong>Oregon State University (Carlos Ochoa)</strong>: Installed instrumentation to monitor soil moisture, temperature, and conductivity fluctuations in under-canopy and inter-canopy locations in juniper woodlands of central Oregon; Installed instrumentation to monitor soil moisture, temperature, and conductivity fluctuations in an irrigated pasture field in Corvallis, Oregon; Continuing data collection and analyses of soil physical properties from the two sites mentioned above.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="13"><br /> <li><strong>Nevada, Desert Research Institute (Markus Berli)</strong>: Developed a model to describe the relationship between soil hydrophobicity and infiltration; developed a model to describe water redistribution in an arid soil.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="14"><br /> <li><strong>Utah State University (Scott Jones and Morteza Sadeghi)</strong>: Initiated work on development of a Utah state-wide soil moisture-mapping and forecasting capability through a Utah Agricultural Experiment Station Seed Grant; Morteza Sadeghi developed a new analytical radiative transfer model to explain effects of particle size on SWIR soil surface reflectance in collaboration with The University of Arizona (Markus Tuller and Ebrahim Babaeian); Wenyi Sheng (Postdoc) developed and field-tested the TDR Array at the TERRA-REF in Maricopa, AZ in collaboration with The University of Arizona (Markus Tuller and Ebrahim Babaeian). The TDR Array supports remote sensing of soil moisture through measurement of near-surface soil moisture in the top 8 cm at 1-cm depth increments; Azadeh Gholoubi (visiting Ph.D. student) developed a novel means for assessing soil aggregate stability using shortwave infrared reflectance of pre-and post-wetted soil aggregates in collaboration with The University of Arizona (Markus Tuller and Ebrahim Babaeian).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="15"><br /> <li><strong>Washington State University (Markus Flury and Joan Wu)</strong>: Showed that biodegradable plastic mulches degrade under composting conditions; Demonstrated that water activities in the driest localities on earth are sufficient to support microbial life; Demonstrated that nanoparticles behave differently than micrometer-sized colloids at the air-water interface;</li><br /> </ol><br /> <p>Showed that the improved Water Erosion Prediction Project (WEPP) model can be applied to forested, mountainous watersheds where groundwater baseflow is important.</p><br /> <p>&nbsp;</p><br /> <ol start="16"><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: Obtained above and below canopy eddy covariance data from collaborators to validate the calculated canopy and energy balances of plot and watershed-scale numerical models; Progress was made towards determining hillslope subsurface hydraulic parameters using time-lapse electrical resistivity tomography data; Applied the integrated watershed model GEOtop to determine the annual water balances for snow-dominated mountainous catchments in Idaho and Wyoming.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="17"><br /> <li><strong>Michigan State University (Wei Zhang):&nbsp; </strong>Investigated the effect of irrigation methods (i.e., overhead vs soil surface irrigation) on pharmaceutical residues and changes of bacterial community and antibiotic resistance genes (ARGs) in greenhouse lettuce leaves, roots, and soils upon exposure to pharmaceuticals in irrigation water. Results showed that the level of pharmaceutical residues in lettuce shoots was greater under overhead irrigation than under soil surface irrigation. One manuscript summarizing the results is currently under review. In addition, results illustrated that pharmaceutical exposure changed the bacterial community and ARG profile. A manuscript on this result is under preparation. Characterized the amount and properties of dissolved organic carbon (DOC) in 46 biochars, and developed a UV-vis spectrophotometry method to predict the DOC concentrations in biochars. The release of DOC from biochars will likely change the sequestration of contaminants by biochars, and is thus very important to development of soil biochar amendment technique. The manuscript on this study is currently under review.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="18"><br /> <li><strong>University of Minnesota (John Nieber):</strong> Quantified the fraction of runoff that will be infiltrated into roadside swale sideslopes based on sideslope hydraulic characteristics and input runoff intensity; Developed modeling methods and sensitivity charts to assess sideslope infiltration potential based on sideslope characteristics (hydraulic conductivity, slope, slope length, and runoff input); Monitored the leaching of nitrate, phosphorus, chloride, a suite of heavy metals, and total petroleum hydrocarbon beneath stormwater infiltration facilities in the Twin Cities Metro Area; Used the HSPF model calibrated for a 9 ha forested watershed in northern Minnesota to assess the impact of potential climate change scenarios on water yield and groundwater recharge; Developed, calibrated and tested a simple dynamic hydrologic model to simulate the nonlinear behavior of groundwater contributions to streamflow for a watershed in eastern California.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong> Outputs</strong></li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Research results were disseminated in collaboration with various involved groups through 7 peer-refereed international journal publications, 1 peer-reviewed article in conference proceedings, and 15 conference contributions.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong>University of California-Davis (Thomas Harter):</strong> <a href="https://www.youtube.com/channel/UCS-mQDuWhJEw7as2XEVhK3A/featured">Video library</a> of over 100 twenty-minute videos that cover a wide range of agricultural groundwater supply and agricultural groundwater quality topics in California, North-America, and five other continents, filmed at the International Conference &ldquo;Toward Sustainable Groundwater in Agriculture, San Francisco, California, June 28-30, 2016&rdquo;; <a href="http://ag-groundwater.org/Conference_Presentations_2016/">Presentation library</a> of over 160 scientific, technical, and policy presentation given at the International Conference &ldquo;Toward Sustainable Groundwater in Agriculture, San Francisco, California, June 28-30, 2016&rdquo;; Sustainable agricultural groundwater banking index (SAGBI) developed for California and available as an online app, <a href="https://casoilresource.lawr.ucdavis.edu/sagbi/">https://casoilresource.lawr.ucdavis.edu/sagbi/</a> ; Published 10 peer-reviewed journal articles, 2 theses and dissertations, and 31 technical and extension publications that are available online (2016 and 2017); Over the two year period 7/1/2015 &ndash; 6/30/2017, gave over 160 presentations in conferences, short courses, and in meetings involving government agencies, a diversity of stakeholder, the general public, and professionals.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong>University of California-Riverside (Hoori Ajami):</strong> Published 5 peer-reviewed journal articles related to groundwater recharge processes and ecohydrology; 1 journal article is currently under review and 3 conference abstracts were published in 2017; Presented the SMART modeling framework in one of the CUAHSI webinars on incorporating hillslope processes into earth system models; Developed and taught 1 upper division undergraduate course regarding principles of groundwater science (4 units).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: Research findings were disseminated via refereed journal publications, conference proceedings, and a number of presentations at national and international meetings. HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects, which in turn have been published in peer-reviewed journals.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="5"><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: Research results were disseminated through 8 peer-refereed international journal publications, 4 presentations and classroom teaching.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol start="6"><br /> <li><strong>University of Delaware (Yan Jin)</strong>: Research results were disseminated in collaboration with various involved groups through 6 peer-refereed international journal publications and 9 conference contributions.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="7"><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Research results were disseminated in collaboration with various involved groups through 20 peer-refereed publications.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="8"><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Research findings were disseminated through 4 journal publications, and presentations.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="9"><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: Published 7 peer-reviewed manuscripts; mentored 2 MS and 5 PhD students as chair and 5 other as committee member; Graduated 1 MS student</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="10"><br /> <li><strong>University of Oklahoma (Tyson Ochsher)</strong>: Maps of annual and long-term average drainage rates across the state of Oklahoma available online at <a href="http://soilmoisture.okstate.edu/html/drainage-map.html">http://soilmoisture.okstate.edu/html/drainage-map.html</a>; Published 1 journal paper; Presented 6 invited talks.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="11"><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Published a paper on the structure of micro-aggregation in sandy soil and their hydrologic impact; Submitted for publication mathematical model describing the fraction of soil water held in the form of liquid films; Submitted for publication a manuscript describing film formation and drainage in two-phase saturated porous media.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="12"><br /> <li><strong>Oregon State University (Carlos Ochoa)</strong>: Presented preliminary findings related to soil moisture differences at different depths in under-canopy and inter-canopy locations in juniper dominated landscapes at a conference.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="13"><br /> <li><strong>Nevada, Desert Research Institute (Markus Berli)</strong>: Published a paper that focused on model development to describe the water dynamics of desert soils.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="14"><br /> <li><strong>Utah State University (Scott Jones and Morteza Sadeghi)</strong>: Research results were disseminated in collaboration with colleagues in the US and China through 7 peer-refereed international journal publications and 22 conference or invited talk contributions.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="15"><br /> <li><strong>Washington State University (Markus Flury and Joan Wu)</strong>: Published research results in peer-reviewed journals and presented the results in national and international conferences (Soil Science Society Annual Meeting, Tampa, FL; European Geoscience Union, Vienna, Austria), and invited talks in China and Germany.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="16"><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: Published 1 journal article and 1 conference abstract in 2017; Taught 4 courses: Soil physics lecture (3 credits), Soil physics laboratory (2 credits), Agroecology capstone (1.5 credits), and Forest and range soils (3 credits)</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="17"><br /> <li><strong>Michigan State University (Wei Zhang):</strong> Published 5 journal articles and presented the results in a number of national and international conferences.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="18"><br /> <li><strong>University of Minnesota (John Nieber):</strong> Published 7 refereed journal articles based on the outcomes of the project activities. Seven conference/outreach presentations (oral or poster) were made.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong> Activities</strong></li><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: <em>(1) Optimization of Soilless Greenhouse Substrates by Adoption and Modification of ParSWMS (Mohammad Gohardoust, Horst Hardelauf, Asher Bar-Tal, and Markus Tuller):</em> Modified the ParSWMS (Hardelauf et al., 2007) code to accommodate nonlinear solute adsorption and to support multi-species solute simulations. <em>(2) Semi-Automated Multiphase Segmentation of 4-D Micro-Computed Tomography (&micro;CT) Data of Porous Media (Ramaprasad Kulkarni, Jeffrey Rodriguez, and Markus Tuller): </em>Developed a new semi-automated multiphase segmentation algorithm by combining K-means (KM) clustering with a Markov random field (MRF) framework. A comparison of segmentation results with KM clustering shows that in the presence of noise inherent to X-ray CT data acquisition, KM-MRF yields fewer misclassification errors than sole KM clustering. <em>(3) Generation of Artificial Porous Materials with Precisely Known Phase Distributions (Ramaprasad Kulkarni, Jeffrey Rodriguez, Marcel Schaap, and Markus Tuller): </em>Because the exact phase (i.e., solid, liquid, and air) boundaries of an imaged porous medium are not known a priori, there is no reliable reference data for meaningful validation of porous media segmentation algorithms. To overcome this problem, a three-phase porous medium proxy with exactly known phase boundaries by using a discrete element method in conjunction with lattice Boltzmann fluid dynamics simulations were synthesized. This approach generates an artificial porous medium with known phase boundaries, comprising spherical particles along with liquid and air. <em>(4) Remote Sensing of Earth Surface Processes: </em>in collaboration with Utah State University (Morteza Sadeghi, Scott Jones, Wenyi Sheng, and Rong Zhou) novel measurement and remote sensing techniques for characterization of largescale near surface processes and basic soil properties are being developed including: <em>(4.1) High-Resolution Shortwave Infrared Imaging of Water Infiltration into Dry Soil (Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, Mahta Moghaddam, and Scott B. Jones):</em> Developed a novel proximal sensing framework for high-resolution soil water content profile retrieval under laboratory conditions. <em>(4.2.) Application of Satellite Remote Sensing for Mapping and Monitoring of Dust Emission Sources (Mohaddese Effati, Ebrahim Babaeian, Morteza Sadeghi, Scott B. Jones, and Markus Tuller):</em> Developed a framework to establish relationships between remotely sensed land surface properties such as soil moisture, soil texture, and vegetation cover and dust events to inform potential dust prevention measures and to establish thresholds for wind erosion susceptibility. <em>(4.3) A Novel Proximal Sensing Approach to Quantifying Soil Aggregate Stability (Azadeh Gholoubi, Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, Scott B. Jones): </em>Developed a framework for quantifying soil aggregate stability using wetting methods in conjunction with hyperspectral imaging. <em>(5) Estimation of Basic Soil Properties from Water Vapor Isotherms: </em>in collaboration with Aarhus and Aalborg Universities in Denmark (Emmanuel Arthur, Lis Wollesen de Jonge and Per Moldrup) further work on indirect estimation of basic soil properties from water vapor sorption isotherms were performed including application of the Guggenheim-Anderson-de Boer model to estimate soil specific surface area from water vapor sorption isotherms.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong>University of California-Davis (Thomas Harter):</strong> <em>(1) </em><em>Innovative Approaches to Understanding and Managing Groundwater-Surface Water Interactions in Agricultural Basins:</em> developed and updated an integrated hydrologic model of the Scott Valley groundwater basin to study the relationship between crop water needs, groundwater pumping for irrigation, and streamflow. The tools have been used for water rights applications to perform winter recharge, and to comply with reporting requirements related to the adjudicated portion of the Scott Valley; <em>(2) Managed Aquifer Recharge in Agricultural Basins: </em>partnered with several colleagues at the Center for Watershed Sciences, UC Water, and with the Public Policy Institute of California to implement cutting edge research that will significantly support sound future decision making by water management districts, reservoir operators, state agencies (including water rights division) to increase the amount of managed aquifer recharge using California&rsquo;s large agricultural landscape as a venue; <em>(3) Nitrate in Groundwater</em>: With funding from CDFA and SWRCB, we have expanded the groundwater nitrate analysis to the entire Central Valley. This includes the assessment of the Central Valley&rsquo;s nitrogen budget dynamics with field-scale spatial resolution and over a 60-year time-span, compilation of groundwater nitrate data, and extensive statistical and numerical modeling analyses to support our understanding of past and current impacts to groundwater, and to develop long-term solutions that will sustain groundwater quality in California&rsquo;s agricultural basins.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong>University of California-Riverside (Hoori Ajami):</strong> Continued on the development of SMART model to extend its capabilities to catchment scale simulations; Added a new uncertainty quantification framework to SMART in collaboration with Boise State University (Mojtaba Sadegh); Establishing a new soil moisture monitoring network in Riverside in collaboration with Andy Gray (UC Riverside). &nbsp;</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol start="4"><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: In 2017, offered three-day short courses on how to use HYDRUS models at a) CSIRO Land &amp; Water, Adelaide, South Australia, Australia, b) Czech University of Life Sciences, Prague, Czech Republic, c) Colorado School of Mines, Golden, CO, d) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China, and e) the Sede Boker Campus of the Ben Gurion University, Israel. Additionally, offered one-day short courses at a) the International Workshop of Soil Physics and the Nexus of Food, Energy and Water, Shenyang, China and b) North Carolina State University, Raleigh, NC. About 170 students participated in these short courses.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="5"><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: Taught hydrology course; Presentations were made to various academic and non-academic groups. Working on the following on-going projects: Decision Support for Water Stressed FEW Nexus Decisions (DS-WSND). NSF INFEWS. 01/01/2018 to 12/30/2020; Reducing Nutrient and Sediment Loss from Ventura and Santa Barbara County Macro-tunnels. California Department of Food and Agriculture. Co-PI. 04/01/2016 to 03/31/2018; Hispanic-Serving Institutions (HSI) Education Grants Program. USDA/NIFA. Co-PI. 10/01/2016 to 08/01/2020; Optimizing Water Management Practices to Minimize Soil Salinity and Nitrate Leaching in California Irrigated Cropland. UC Division of Agri. &amp; Natural Res. PI. 03/2017-02/2019.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="6"><br /> <li><strong>University of Delaware (Yan Jin)</strong>: <em>(1) A</em><em>dvancing mechanistic understanding of plant growth promoting rhizobacteria (PGPR):</em> found that all PGPR-treated soils held more water and had reduced hydraulic conductivity and accumulative evaporation, compared to their corresponding controls; <em>(2) Quantified transport and retention behaviors of a human pathogenic virus (Adenovirus 41 or Ad-41) a model bacteriophage (</em>f<em>X174) through metal oxide-removed and goethite-coated sand under saturated flow conditions</em>. The results clearly demonstrated that caution must be taken when applying laboratory results, which are generally obtained from experiments employing a single virus species to predict the mobility and environmental risks in natural systems where multiple agents are present. <em>(3) S</em><em>ystematically investigated the influence of CAC and collector surface heterogeneity on the detachment of colloids by conducting saturated sand column experiments.</em> We observed that the fraction of attached colloids that were detached (i.e., reversibly attached colloids, denoted as FRA) due to reducing ionic strength (IS) changed with the CAC. Scanning electron microscope examinations reveal that the concave regions favored irreversible colloid attachment. Reversible attachment is likely due to immobilization on flat surfaces with charge heterogeneities, retention in stagnation point regions via secondary minimum association, ripening in the acid-treated sand, and capture of colloids by protruding asperities with charge heterogeneity in the untreated sand. Findings have important implications for predicting the fate and transport of colloids in subsurface environments and design of surfaces for manipulating colloid deposition and release in engineered processes; <em>(4) </em><em>Graphene oxide nanomaterials (GONMs) have novel physicochemical properties thus a great potential to be used in medical, energy, and environmental applications:</em> Understanding the fate and transport of GONMs in the subsurface is necessary for their benign use as well as providing assessment of their environmental impacts and health risks. Our findings advance current knowledge to better predict NMs' fate and transport under various solution chemistries such as during rainfall events or in the mixing zones between sea water and fresh water where transient IS can change drastically; <em>(5) Continued collaboration with colleagues Dr. Jie Zhuang (Institute of Applied Ecology, Shengyang, of the Chinese Academy of Sciences and University of Tennessee) and Dr. Chongyang Shen (China Agricultural University, Beijing)</em> on fate and transport of colloids and viruses, and initiated new collaboration with Dr. Yan Xue of Nanjing University of Information Science &amp; Technology on ecotoxicological studies of heavy metal cadmium.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="7"><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Introduced the heat pulse method for measuring surface soil heat flux with a multi-needle heat-pulse probe (HPP); Presented a heat pulse-based method for simultaneous determination of r_b and q from soil thermal properties; Extended the van Genuchten WRC model to account for &rho;b variations; Presented and evaluated a soil thermal conductivity (&lambda;)-based approach to determine &theta;i with thermo-TDR probes; Evaluated the accuracy and precision of the heat-pulse technique using direct, continuous, and nondestructive E measurements from a weighing lysimeter. Results showed that heat-pulse technique can provide continuous daily E measurements with good accuracy and precision.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="8"><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Installed wireless sensor network for soil water content monitoring in a farmer's field; Performed functional soil mapping for management decision support; Further progress was made in linking remotely sensed field information to soil processes; Continued to use the Root Zone Water Quality Model (RZWQM) to simulate soil water dynamics, crop growth and greenhouse gas emissions; Almost completed the 3-year research project that is funded by the three main crop commodities in Kentucky; Over the next months, we will complete two Ph.D. dissertations; Worked on the decision support for irrigation water management, and at the same time coordinating group of scientists from three other states (Georgia, Tennessee, Alabama) and our 4-state research project is funded by the SSRP (Southern Soybean Research Program). Scientists involved in this project writing effort here at UK are: Chad Lee, Carrie Knott, Mike Sama, and Lloyd Murdock. A continuation of the proposal for year 3 has been submitted; Smart Phone App is being under development that will help farmers to control their irrigation system; Continued mentoring of graduate students, giving invited lectures overseas, and being active in a number of Extension and Outreach activities.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="9"><br /> <li><strong>New Mexico State University (Shukla Manoj)</strong>: Taught soil physics, advanced soil physics and environmental soil science classes; Taught a class on Natural Resources in Northwest A&amp;F University, China; Hosted one faculty members from University of Hebei, China, one faculty from Jiangxi Agriculture University of China, and one graduate student from China agriculture University; Organized field and greenhouse trips to collect soil and water samples, soil moisture content, soil temperature, and other meteorological data; Planned experiments on the use of brackish groundwater and RO concentrate for looking at the influence of irrigation water salinity on soil microbiological properties; Collected soil and plant samples from Pecan orchards from Hatch, NM to Fabens, Texas to evaluate salinity induced changes in pecan physiology; wrote multiple proposals; Evaluated Indaziflam movement through preferential flow channels and its impact on Pecan growth and gas exchange parameters, and soil properties; Started on developing a device to remotely collect soil moisture content data by commercially available sensors.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="10"><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Published a peer-reviewed paper on demonstrating how useful drainage estimates can be obtained from a large-scale soil moisture monitoring network by applying the unit-gradient assumption; Distributed drainage maps to the public and to other researchers through the website listed previously; Presented results at multiple scientific meetings and conferences.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="11"><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Investigating soil water relations in sandy agricultural soil to improve irrigation efficiency [Collaboration with M. Kleber and R. Qin (OSU)]; Continuing field and laboratory investigations associated with the evolutionary development of micro-aggregation in sandy soil; Investigating the biophysical mechanisms associated with the evolution of water repellency to uncover an effective remediation strategy [Collaboration with M. Kleber (OSU)]; Continuing laboratory investigations of water repellency development; Investigating the erosional evolution of microfractures in the epikarst; Completed experiments and initiation of final data analysis; Investigating the efficacy of using soil solarization for pest and weed disinfectation in the Pacific Northwest [Collaboration with J. Parke and C. Mallory-Smith (OSU) and S. Dollen (Grower)]; Completed second-year of field trials; Investigating how various mechanisms impact gas exchange across the interface between vadose zone and atmosphere [Collaboration with N. Weisbrod (Ben Gurion, IL)]; Investigation of film flow below the detection limit of CT scans [Collaboration with PI Dorthe Wildenschild]; Submitted one manuscript submitted, second manuscript is in progress.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="12"><br /> <li><strong>Oregon State University (Carlos Ochoa)</strong>: <em>(1) </em><em>Investigate soil water relations in irrigated pastures to assess water transport through the vadose zone and into the shallow aquifer [Collaboration with D. Godwin and S. Ates (OSU)]:</em> Field and laboratory work related with soil physical properties and water transport through the unsaturated zone; <em>(2) Investigate soil water relations in juniper-sage steppe landscapes to assess water transport through the vadose zone and into the shallow aquifer [Collaboration with T. Deboodt (OSU)]</em>: Automated field data collection at multiple locations in one watershed with juniper and one where juniper was removed 13 years ago.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="13"><br /> <li><strong>Nevada, Desert Research Institute (Markus Berli)</strong>: Developed a physically-based model to describe the relationship between soil hydrophobicity (expressed as apparent contact angle) and infiltration; Worked on an improved understanding of water infiltration, redistribution and evaporation from arid soils; Evaluated a soil test kit to assess the health of desert soils</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="14"><br /> <li><strong>Utah State University (Scott Jones and Morteza Sadeghi)</strong>: <em>(1) Effects of Particle Size on Soil Reflectance (Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, and Scott B. Jones): </em>Developed a novel algorithm and tested it for estimation of soil particle size effects on surface reflectance in the optical domain (i.e., 400-2500 nm). <em>(2) Estimation of Actual Evapotranspiration in Stony Soils (Kshitij Parajuli, Morteza Sadeghi and Scott B. Jones):</em> Extended research on stony soil water retention for actual evapotranspiration determination using measured changes in soil moisture coupled with numerical modeling. <em>(3) A Novel Proximal Sensing Approach to Quantifying Soil Aggregate Stability (Azadeh Gholoubi, Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, Scott B. Jones):</em> Developed a proximal sensing (RS) technique for quantifying soil aggregate stability. <em>(3) A TDR Array Probe for Monitoring Near-surface Soil Moisture Distribution (Wenyi Sheng, Rong Zhou, Morteza Sadeghi, David A. Robinson, Markus Tuller, and Scott B. Jones):</em> The TDR array was fully described in a Vadose Zone Journal publication in 2017. The probe was designed to provide cm-resolution measurements of soil moisture content from the surface downward. <em>(4) High-Resolution Shortwave Infrared Imaging of Water Infiltration into Dry Soil (Morteza Sadeghi, Ebrahim Babaeian, Markus Tuller, Mahta Moghaddam, and Scott B. Jones): </em>Developed a novel proximal sensing framework for high-resolution soil water content profile retrieval under laboratory conditions and results were published in Vadose Zone Journal; <em>(5) Application of Satellite Remote Sensing for Mapping and Monitoring of Dust Emission Sources (Mohaddese Effati, Ebrahim Babaeian, Morteza Sadeghi, Scott B. Jones, and Markus Tuller): </em>Developed a framework to establish relationships between remotely sensed land surface properties such as soil moisture, soil texture, and vegetation cover and dust events to inform potential dust prevention measures and to establish thresholds for wind erosion susceptibility; <em>(6) Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns and gravel lenses (H. Abdu, D. A. Robinson, J. L. Boettinger and S. B. Jones):</em> In a FASE publication, described an electromagnetic induction (EMI) mapping approach in low apparent electrical conductivity (ECa) soils under varying soil water contents to capture time invariant properties such as soil texture. Georeferenced ECa measurements were taken using a ground conductivity meter on six different days where volumetric water content (&theta;v) varied from 0.11 to 0.23. Combined maps using temporal stability analysis gave the clearest image of the textural differences. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications; <em>(7) A Utah Soil Moisture Monitoring and Forecast Network for Improved Water Resource Management and Risk Prediction. (Wenyi Sheng, Rong Zhou, Morteza Sadeghi, Rob Gillies, Markus Tuller and Scott B. Jones).</em> The Utah Agricultural Experiment Station funded a seed grant to develop a state-wide Utah Soil Moisture Map and Forecast. We are collaborating with the Utah Climate Center and the University of Arizona to develop external grant proposal in order to fully develop the capability of both mapping soil moisture as well as to forecast soil moisture into the future.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="15"><br /> <li><strong>Washington State University (Markus Flury and Joan Wu)</strong>: Synthesizing work on colloid transport in unsaturated porous media; Co-edited a special section on &ldquo;Lysimeters in Vadose Zone Research&rdquo; in the Vadose Zone Journal; Organized symposium on &ldquo;Nanoparticle Fate and Transport in Soil and Groundwater Systems&rdquo; at the European Geoscience Union Annual meeting; Measured water potentials and sorption isotherms for soil samples from Atacama desert to determine the dry limit of life on Earth; Used numerical modeling to assess the effect of biodegradable plastic mulches on water dynamics in field soils; Performed field experiment to assess suitability of biodegradable plastic mulches for pumpkin production; Measured soil quality in field trials to check for adverse effects of biodegradable plastic mulches; Tested degradation of biodegradable plastic mulches under soil and compost conditions; Improved the Water Erosion Prediction Project (WEPP) model for groundwater baseflow, and applied the model to the Upper Cedar River Watershed in western Washington.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol start="16"><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: Continue to maintain a state-wide soil moisture network for drought monitoring in rangelands (consisting of 17 sites); Continue to maintain 3 snow-soil monitoring stations, 6 soil moisture monitoring stations, and 2 snow lysimeters (measuring snowmelt rates) in a forested experimental watershed in southeastern Wyoming; Developed a novel bulk density optimization method to determine subsurface hydraulic properties for use in numerical plot, hillslope, and watershed-scale numerical models.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="17"><br /> <li><strong>Michigan State University (Wei Zhang): </strong>Investigated the effect of irrigation methods (i.e., overhead vs soil surface irrigation) on pharmaceutical residues and changes of bacterial community and antibiotic resistance genes (ARGs) in greenhouse lettuce leaves, roots, and soils upon exposure to pharmaceuticals in irrigation water; Characterized the amount and properties of dissolved organic carbon (DOC) in 46 biochars, and developed a UV-vis spectrophotometry method to predict the DOC concentrations in biochars.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="18"><br /> <li><strong>University of Minnesota (John Nieber): </strong>Conducted field experiments at highway swale sites to quantify the pattern of overland flow and the amount of infiltrated runoff on the highway swale surfaces; Developed a model for one-dimensional overland flow with vertical infiltration to simulate the infiltration of stormwater generated on highway surfaces, into the sideslopes of swales; Developed a model for infiltration from parallel strip sources to quantify the effect of strip width and strip spacing on the total infiltration over a surface, with reference to the infiltration that would occur for a condition of a completely wetted surface. The model was based on a 2-dimensional solution of the Richards equation and implemented in the COMSOL-MP software; Developed a model for turbulent flow, particle erosion, and suspended sediment transport inside of soil pipes using COMSOL-MP software. The model was for steady-state flow and for a fixed pipe geometry. The research is part of a continued collaboration with Dr. Glenn Wilson at the USDA-ARS sedimentation lab in Oxford, MS and Dr. Garey Fox at North Carolina State University; Conducted detailed laboratory studies on a large laboratory hillslope to investigate the infiltration of water where the water enters from the upper end of the flume and overland flow occurs down the slope; Monitored three stormwater infiltration practice sites in the Twin Cities Metro Area to determine the rate of mass transport for select heavy metals, nitrate, phosphorus, chloride, and Total Petroleum Hydrocarbon (TPH); Continued research on the characteristics of the vadose zone flow processes at a large area made water repellent by an oil pipeline spill that occurred in 1978; Developed the HSPF model of a 9 ha forested watershed in northcentral Minnesota. This modeling work is a collaboration with Dr. Stephen Sebestyen at the U.S. Forest Service office in Grand Rapids, MN; A calibrated GSFLOW model for the Sagehen Creek watershed (27 sq. km) located in Sierra Nevada Mountains) was used to synthetically generate baseflow recessions for a 16-year period. The generated baseflow recessions were examined to assess the effect of initial groundwater storage, groundwater recharge, and ET on recession characteristics; Using results of the Sagehen Creek watershed modeling study a simple dynamic model of watershed hydrology was developed to simulate groundwater contributions to streamflow. The developed model was calibrated for one single parameter for an 8-year period and then the calibrated model was validated using an independent 8-year record of streamflow.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li><strong> Milestones</strong></li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol><br /> <li><strong>University of Arizona (Markus Tuller)</strong>: Modified ParSWMS parallelized code to include simulation capabilities for nonlinear solute adsorption and multi-species solute simulations for optimization of soilless greenhouse substrates; Developed a method for semi-automated multiphase segmentation of 4-D Micro-Computed Tomography (mCT) data of porous media; Refined predictive capabilities for soil specific surface area based on the Guggenheim&ndash;Anderson&ndash;Boer sorption model; Developed a new analytical radiative transfer model to explain effects of particle size on SWIR soil surface reflectance; Developed new means to measure soil aggregate stability with SWIR imaging.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol start="2"><br /> <li><strong>University of California-Davis (Thomas Harter):</strong> Held the International Conference &ldquo;Toward Sustainable Groundwater in Agriculture&rdquo;, June 28-30, 2016&rdquo;, which was attended by over 350 participants from 6 continents. The conference was preceded by 2 half-day workshops on groundwater nitrogen management and on the implementation of the California Sustainable Groundwater Management Act. The conference brought together a unique diversity of speakers and attendees from water sciences, agricultural extension, agricultural organizations, NGOs, government organizations, and growers; Completed a multi-year assessment of the spatial and long-term temporal distribution of nitrogen losses to groundwater that threaten drinking water resources that most of the population in the Central Valley depends on. The assessment, for the first time, provides detailed mass balance at the one-acre scale across the 12 million acre Central Valley; Katherine Ransom completed her dissertation, a body of work that is complementary to the nitrogen mass balance analysis of the Central Valley (<a href="https://californiawaterblog.com/2017/09/17/groundwater-nitrate-sources-and-contamination-in-the-central-valley/">https://californiawaterblog.com/2017/09/17/groundwater-nitrate-sources-and-contamination-in-the-central-valley/</a>); (4) Emily Edwards completed her MS thesis, a comprehensive assessment of dry wells as tool for urban stormwater recharge.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol start="3"><br /> <li><strong>University of California-Riverside (Hoori Ajami):</strong> The SMART modeling framework was published online and is available to users; Worked on recharge estimation in the western US; Worked on ecohydrologic modeling applications</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li><strong>University of California-Riverside (Jirka Simunek)</strong>: Various novel applications of the models were implemented including: application of the machine learning method to estimate the main wetting branch of soil water retention curve based on its main drying branch; evaluation of the role of heterogeneous lithology; simulating overland flow processes, quantifying the long-term stream-aquifer exchange in a variably saturated heterogeneous environment; evaluating transport and fate of viruses under managed aquifer recharge (MAR); modifying HYDRUS-1D to consider particle dissolution to evaluate dissolution and transport of energetic constituents from the new insensitive munitions (IM) formulations IMX-101, a mixture of NTO, NQ, and DNAN, and IMX-104, a mixture of NTO, RDX, and DNAN. NTO and DNAN; Developing a root growth model, and publication of two review papers.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="5"><br /> <li><strong>University of California-Riverside (Laosheng Wu)</strong>: Improve our fundamental understanding of vadose zone physical properties and processes, and how they interact with other environmental and biogeochemical processes across various spatial and temporal scales; Apply our knowledge of scale-appropriate methodologies to enhance the management of vadose zone resources that benefit agricultural systems, natural resources and environmental sustainability.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="6"><br /> <li><strong>University of Delaware (Yan Jin)</strong>: Implemented novel experimental approaches and demonstrated that PGPR can increase soil water retention and reduce evaporation from soils; Demonstrated how co-presence of two viruses affected the retention and transport behavior of each (e.g., reduced retention hence increased transport due to competition for attachment sites); and Improved understanding of colloid behavior in porous media.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="7"><br /> <li><strong>Iowa State University (Robert Horton)</strong>: Developed a heat pulse sensor method to measure surface and subsurface soil heat fluxes; Developed a heat pulse sensor method to determine soil water content and soil bulk density simultaneously; Developed a method to estimate soil water retention curves as a function of bulk density; Developed a thermo-TDR method to measure soil ice content.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="8"><br /> <li><strong>University of Kentucky (Ole Wendroth)</strong>: Refining and troubleshooting a wireless sensor network for soil water content monitoring in a farmer&rsquo;s field; Made substantial progress in mapping zone delineation for irrigation decision support; Made progress in linking remotely sensed field information to soil processes.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="9"><br /> <li><strong>New Mexico State University (Manoj Shukla)</strong>: Quantified impacts of irrigation water salinity induced changes to evapotranspiration and yields of several chile pepper cultivars; Quantified impacts of irrigation water salinity induced changes to evapotranspiration and yields of several halophytes; Quantified increases in soil salinity and ion concentrations in soil with continued irrigation with brackish groundwater and RO concentrate; Showed Clinoptilolite zeolite can be used to wick water from groundwater tables to support native vegetation; Quantified dissipation rates and half-life of indaziflam herbicide; Quantified various airborne fungal spores along US-Mexico border; Calibrated three soil moisture sensors (Hydra probe, 5TE, and 5TM sensors); Started on developing a low cost data logger with wireless capability to collect data at a location and directly transmit to central storage; Quantified dissipation rates for indaziflam for management of Pecan orchards; Quantified ion accumulation in soil and plant for designing improved irrigation strategies</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="10"><br /> <li><strong>University of Oklahoma (Tyson Ochsner)</strong>: Explored the potential for expanding this drainage estimation method nationwide using existing soil moisture monitoring networks.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="11"><br /> <li><strong>Oregon State University (Maria Dragila)</strong>: Continuing work on water motion within sandy soils has resulted in the development of a conceptual field-scale model for the role of biofilms on water storage within the upper-soil water cycle.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="12"><br /> <li><strong>Oregon State University (Carlos Ochoa)</strong>: Established a soil moisture-monitoring network in one irrigated pasture field in the Oak Creek watershed in Corvallis, OR.;</li><br /> </ol><br /> <p>Expanded a soil moisture-monitoring network in rangeland juniper-dominated systems in central Oregon.</p><br /> <p>&nbsp;</p><br /> <ol start="13"><br /> <li><strong>Nevada, Desert Research Institute (Markus Berli)</strong>: Developed a model for water infiltration into hydrophobic soils; Developed a model to describe water redistribution in arid soils</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="14"><br /> <li><strong>Utah State University (Scott Jones and Morteza Sadeghi)</strong>: Developed a new analytical radiative transfer model to explain effects of particle size on SWIR soil surface reflectance; Developed new means to measure soil aggregate stability with SWIR imaging; Received private grant to modify the tri-needle heat pulse probe for reduced energy consumption and improved longevity of the sensor heater; Published a description and application of the TDR Array for measurement of near-surface soil moisture in cm depth increments; Published the Optical Trapezoiod Model (OPTRAM) paper for improved remote sensing of land surface moisture content using only optical satellite data; Initiated Utah state-wide soil moisture mapping and forecasting project using UAES seed grant.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="15"><br /> <li><strong>Washington State University (Markus Flury and Joan Wu)</strong>: Developed mechanistic understanding of interactions of colloids with the air-water interface; Determined vapor sorption isotherms to evaluate the dry-limits of life; Developed a numerical model to analyze the effects of biodegradable plastic mulches on soil moisture; Completed a third of four field seasons to evaluate the effects of biodegradable plastic mulches on soil quality; Incorporated nonlinear algorithms into WEPP (v2012.8) for estimating baseflow.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="16"><br /> <li><strong>University of Wyoming (Thijs Kelleners)</strong>: Soil Science MS student Mark Pleasants successfully defended his thesis entitled: Hydrologic flow paths for a snowmelt dominated, forested hillslope in southeastern Wyoming: Linking snow and subsurface hydrology. One paper was published from this work in Hydrological Processes. Mark is currently a hydrologist at the Ohio Geological Survey.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="17"><br /> <li><strong>Michigan State University (Wei Zhang): </strong>This project provided training for one undergraduate student, four graduate students, and one post-doctorate research</li><br /> </ol><br /> <p>Associate.</p><br /> <p>&nbsp;</p><br /> <ol start="18"><br /> <li><strong>University of Minnesota (John Nieber): </strong>Stormwater runoff generated on highways was observed to occur in concentrated flow patterns over the surface of highway swale sideslopes, even in the absence of rills on the surface; Developed a prediction model that facilitates the calculation of the fraction of surface wetted with overland flow based on sideslope characteristics (mainly saturated hydraulic conductivity) and applied runoff intensity; Developed overland flow model was shown to match measured runoff amounts, without calibration, using only measured sideslope characteristics; The calibrated HSPF model applied to a headwater watershed in northern Minnesota showed that with projected changes in air temperature and rainfall the runoff from the headwater watershed will be reduced during the growing season, and groundwater recharge will also be reduced; The simple dynamic hydrologic model applied to the Sagehen Creek watershed was shown to match quite well (NSE &gt; 0.85) the groundwater portion of streamflow for the creek. The model improves upon previous models by accounting for the nonlinear behavior of the storage-discharge relations in watersheds.</li><br /> </ol>

Publications

<ol><br /> <li>Abdu, Hiruy David A. Robinson, Janis Boettinger, Scott B. Jones. 2017. Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns and gravel lenses. <em> Agr. Sci. Eng.</em> 4(2): 135-145, doi: 10.15302/J-FASE-201714</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li>Aggarwal, P., R. Bhattacharyya, A. K. Mishra, T. K. Das, J. &Scaron;imůnek, P. Pramanik, S. Sudhishri, A. Vashisth, Krishnan, D. Chakraborty, and K. H. Kamble, Modelling soil water balance and root water uptake in cotton grown under different soil conservation practices in the Indo-Gangetic Plain, <em>Agriculture, Ecosystems &amp; Environment</em>, <em>240</em>, 287-299, doi: 10.1016/j.agee.2017.02.028, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li>Ajami, H., A. Sharma, L.E. Band, J.P. Evans, N. K. Tuteja, G.E. Amirthanathan, M.A. Bari. 2017. On the Non-stationarity of Hydrological Response in Anthropogenically Unaffected Catchments: An Australian Perspective, Hydrology and Earth System Sciences, doi:10.5194/hess-21-281-2017</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li>Aller, D., K. Moore, R. Hintz. D. Laird, and R. Horton. 2017. Biochar age and crop rotation impacts on soil quality. Soil Sci. Soc. Am. J. 81:1157&ndash;1167. doi:10.2136/sssaj2017.01.0010.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="5"><br /> <li>Arthur, E., M. Tuller, P. Moldrup, M.H. Greve, M. Knadel, and L.W. DE Jonge, 2017. Applicability of the Guggenheim&ndash;Anderson&ndash;Boer water vapour sorption model for estimation of soil specific surface area. Eur. J. Soil Sci., 69(1), doi: doi: 10.1111/ejss.12524</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="6"><br /> <li>Arthur, J. D., N. W. Mark, S. Taylor, J. &Scaron;imůnek, M. L. Brusseau, and K. M. Dontsova, Batch soil adsorption and column transport studies of 2,4-dinitroanisole (DNAN) in soils, <em>Journal of Contaminant Hydrology</em>, <em>199</em>, 14-23, doi: 10.1016/j.jconhyd.2017.02.004, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="7"><br /> <li>Arthur, J. D., N. W. Mark, S. Taylor, J. &Scaron;imůnek, M. L. Brusseau, and K. M. Dontsova, Dissolution and transport of insensitive munitions formulations IMX-101 and IMX-104 in saturated soil columns, <em>Science of Total Environment</em>, (in press).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="8"><br /> <li>Baath G. S., M. K. Shukla, P. W. Bosland, R. L. Steiner, and S. J. Walker. 2017. Irrigation Water Salinity Influences at Various Growth Stages of <em>Capsicum annuum</em>. Ag Water Management. 179: 246-253.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="9"><br /> <li>Baram, S., V. Couvreur, T. Harter, M. Read, P.H. Brown, M. Kandelous, D.R. Smart, and J.W. Hopmans, 2016. Estimating Nitrate Leaching to Groundwater from Orchards: Comparing Crop Nitrogen Excess, Deep Vadose Zone Data-Driven Estimates, and HYDRUS Modeling. Vadose Zone J. 15. doi:10.2136/vzj2016.07.0061.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="10"><br /> <li>Baram S., V. Couvreur, T. Harter, M. Read, P.H. Brown, J.W. Hopmans, D.R. Smart, 2016. Assessment of orchard N losses to groundwater with a vadose zone monitoring network. Agricultural Water Management 172:83-95. doi:10.1016/j.agwat.2016.04.012</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="11"><br /> <li>Brunetti, G., J. &Scaron;imůnek, M. Turco, and P. Piro, On the use of surrogate-based modeling for the numerical analysis of Low Impact Development techniques, <em>Journal of Hydrology</em>, <em>548</em>, 263-277, doi: 1016/j.jhydrol.2017.03.013, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="12"><br /> <li>Brunetti, G., H. Saito, T. Saito, and J. &Scaron;imůnek, <a name="_Toc480017519"></a>A computationally efficient pseudo-3D model for the numerical analysis of borehole heat exchangers, <em>Applied Energy</em>, <em>208</em>, 113-1127, doi.: 10.1016/j.apenergy.2017.09.042, 2017 (IF=7.18).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="13"><br /> <li>Caruso P., C. Ochoa, T. Deboodt and T. Jarvis. 2017. Influence of hydrogeology on groundwater dependent ecosystems. OSU-Research Progress Report. 16 pp.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="14"><br /> <li>Chen, Z., W. Zhang, G. Wang, Y. Zhang, Y. Gao, S.A. Boyd, B.J. Teppen, J.M. Tiedje, D. Zhu, and H. Li. 2017. Bioavailability of soil-sorbed tetracycline to Escherichia coli under unsaturated conditions. Environmental Science &amp; Technology, 51(11), 6165-6173.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="15"><br /> <li>Darzi-Naftchali, A., F. Karandish, and J. &Scaron;imůnek, Numerical modeling of soil water dynamics in subsurface drained paddies with midseason drainage or alternate wetting and drying management, <em>Agricultural Water Management</em>, <em>197</em>, 67-78, doi: 10.1016/j.agwat.2017.11.017,</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="16"><br /> <li>Diamantopoulos, E., J. &Scaron;imůnek, C. Oberd&ouml;rster, K. Hammel, B. Jene, T. Schr&ouml;der, and T. Harter, Assessing the potential risk of groundwater to pesticides &ndash; a model comparison, <em>Vadose Zone Journal</em>, <em>16</em>(11), pp. 13, doi: 2136/vzj2017.04.0070, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="17"><br /> <li>Diamantopoulos, E., J. Simunek, C. Oberdoerster, K. Hammel,B. Jene, T. Schroeder, and T. Harter, 2017. Asessing the potential exposure of groundwater to pesticides: A model comparison. Vadose Zone J. 16(11), 13 pages, doi:10.2136/vzj2017.04.0070.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="18"><br /> <li>Diamantopoulos, E., W. Durner, T. Harter, Prediction of capillary air-liquid interfacial area vs. saturation function from relationship between capillary pressure and water saturation, Advances in Water Resources, Volume 97, November 2016, Pages 219-223, ISSN 0309-1708, doi:10.1016/j.advwatres.2016.09.012.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="19"><br /> <li>Dijkema, J., J.E. Koonce, R.M. Shillito, T.A. Ghezzehei, M. Berli, M. van der Ploeg, et al. 2017. Water Distribution in an Arid Zone Soil: Numerical analysis of data from a large weighing lysimeter. Vadose Zone Journal. doi:10.2136/vzj2017.01.0035.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="20"><br /> <li>Dokoohaki, H., F.E. Miguez, D. Laird, R. Horton, and A.S. Basso. 2017. Assessing the biochar effects on selected physical properties of a sandy soil: an analytical approach, Communications in Soil Science and Plant Analysis, DOI:10.1080/00103624.2017.1358742.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="21"><br /> <li>D&ouml;rner, J., R. Horn, D. Dec, O. Wendroth, H. Fleige, and F. Zunigaugalde. 2017. Land-use-dependent change in the soil mechanical strength and resilience of a shallow volcanic ash soil in southern Chile. Soil Sci. Soc. Am. J. 81:1064-1073.</li><br /> <li>Durfee, N. and C. Ochoa. 2017. Stream temperature dynamics in a semiarid riparian system in northcentral Oregon. 2017. OSU-Research Progress Report. 14 pp.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="23"><br /> <li>Edwards, E. C., Harter, T., Fogg, G. E., Washburn, B., &amp; Hamad, H. (2016). Assessing the Effectiveness of Drywells as Tools for Stormwater Management and Aquifer Recharge and Their Groundwater Contamination Potential. Journal of Hydrology 539:539-553, doi:10.1016/j.jhydrol.2016.05.059.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="24"><br /> <li>Flores A., M.K. Shukla, B. Schutte, G. Picchioni, and D. Daniel. 2017. Physiologic response of six plant species grown in two contrasting soils and irrigated with brackish groundwater and RO concentrate. Arid land Res. and Manag. Journal. 31:182-203.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="25"><br /> <li>Flury, M., and S. Aramrak, Role of air-water interfaces in colloid transport in porous media: A review, Water Resour. Res., 53, 5247&ndash;5275, 2017. (dx.doi.org/10.1002/2017WR020597)</li><br /> <li>Gao, Y., X. Hu, Z. Zhou, W. Zhang, Y. Wang, and B. Sun. 2017. Phytoavailability and mechanism of bound PAH residues in filed contaminated soils. Environmental Pollution, 222, 465-476.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="27"><br /> <li>Gao, Z., Tong, B., Horton, R., Mamtimin, A., Li, Y., &amp; Wang, L. 2017. Determination of desert soil apparent thermal diffusivity using a conduction-convection algorithm. J. Geophysical Research: Atmospheres, 122. 9569&ndash;9578, doi.org/10.1002/2017JD027290.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="28"><br /> <li>Garcia-Serrana, M., J.S. Gulliver and J.L. Nieber, 2017. Non-uniform overland flow-infiltration model for roadside swales, J. Hydrol., 552: 586&ndash;599.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="29"><br /> <li>Garcia-Serrana, M., J.S. Gulliver and J.L. Nieber, 2017. Infiltration capacity of roadside filter strips with non-uniform overland flow, J. Hydrol., 545: 451&ndash;462.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="30"><br /> <li>Garcia-Serrana, M., J.L. Nieber and J.S. Gulliver, 2017. Infiltration flux for parallel strip water sources, Vadose Zone J., doi:10.2136/vzj2017.07.0137.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="31"><br /> <li>Gemitzi, A., H. Ajami, H. Richnow. 2017. 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Weighing lysimeter data confirm the accuracy and precision of the heat-pulse technique for measuring daily soil evaporation. Soil Sci. Soc. Am. J. 81:1074&ndash;1078, doi:10.2136/sssaj2017.02.0049n.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="110"><br /> <li>Wang, Y., X. Zhang, X. Xiao, J. Heitman, R. Horton, and T. Ren. 2017. An empirical calibration for heat-balance sap-flow sensors in maize. Agron. J. 109:1&ndash;7, doi:10.2134/agronj2016.10.0611.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="111"><br /> <li>Wang, Z., M. Ankeny, and R. Horton. 2017. The impact of water vapor diodes on soil water redistribution. J. Hydrology 552:600&ndash;608. doi.org/10.1016/j.jhydrol.2017.07.009.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="112"><br /> <li>Wang, Z., R. Schwartz, Y. Kojima, Y. Chen, and R. Horton. 2017. A comparison of second-order derivative based models for time domain reflectometry waveform analysis. Vadose Zone J. 16. doi:10.2136/vzj2017.01.0014.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="113"><br /> <li>Wendroth, O. 2017. Wilfried Ehlers &ndash; Agronomist and Soil Physicist. Editorial. Soil Till. Res. 171:A1-A2, http://dx.doi.org/10.1016/ j.still.2017.04.005.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="114"><br /> <li>Wilson, G.V., J.L. Nieber, G.A. Fox, SM Dabney, M. Ursic, and J.R. Rigby, 2017. Threshold behavior of catchments with duplex hillslope soils feeding soil pipe networks, Hydrol. Process. J., 31: 1&ndash;20.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="115"><br /> <li>Wilson, G.V., R.R. Wells, R. Kuhnle, G.A. Fox, J.L. Nieber, 2017. Sediment detachment and transport processes associated with internal erosion of soil pipes: Often overlooked processes of gully erosion, Earth Surf. Proc. Landforms, DOI: 10.1002/esp.4147.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="116"><br /> <li>Wyatt, B.M., T.E. Ochsner, C.A. Fiebrich, C.R. Neel and D.S. Wallace. 2017. Useful drainage estimates obtained from a large-scale soil moisture monitoring network by applying the unit-gradient assumption. Vadose Zone J. 16. doi:10.2136/vzj2017.01.0016.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="117"><br /> <li>Xu, S, R. Attinti, E. Adams, J. Wei; K. Kniel, J. Zhuang*, Y. Jin. 2017. Mutually facilitated co-transport of two different viruses through reactive porous media. <em>Water Res</em>. 123:40-48. doi: 10.1016/j.watres.2017.06.039</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="118"><br /> <li>Xue, Y., W. J. G. M. Peijnenbury, J. Huang, D. Wang, and Y. Jin. 2018. Tropic transfer of cadmium from Duckweed (<em>Lemna minor L.</em>) to Tilapia (<em>Oreochromis mossambicus</em>). DOI: 10.1002/etc.4076 <em>Environ Toxicol &amp; Chem</em>. (in press)</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="119"><br /> <li>Yan, J., X. Meng, and Y. Jin. 2017. Size-dependent turbidimetric quantification of suspended soil colloids. <em>Vadose Zone J</em>. 16(5). doi:10.2136/vzj2016.10.0098.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="120"><br /> <li>Yang, W., Y. Wang, P. Sharma, B. Li, K. Liu, J. Liu, M. Flury, and J. Shang, Effect of naphthalene on transport and retention of biochar colloids through saturated porous media, Colloids Surf. Physicochem. Eng. Aspects, 530, 146&ndash;154, 2017. (dx.doi.org/10.1016/j.colsurfa.2017.07.010)</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="121"><br /> <li>Ying, S., Jiangjiang Zhang, Lingzao Zeng, Jiachun Shi, Laosheng Wu. Bayesian inference for kinetic models of biotransformation using a generalized rate equation. Science of the Total Enviroment. (2017). 592: 287-296.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="122"><br /> <li>Zhang, J., Weixuan Li, Guang Lin, Lingzao Zeng, Laosheng Wu. Efficient evaluation of small failure probability in high-dimensional groundwater contaminant transport modeling via a two-stage Monte Carlo method. Water Resources Research. (2017). 53: 1948-1962.</li><br /> <li>Zhang, M., S. A. Bradford, J. &Scaron;imůnek, H. Vereecken, and E. Klumpp, Roles of cation valance and exchange on the retention and colloid-facilitated transport of functionalized multi-walled carbon nanotubes in a natural soil, <em>Water Research</em>, <em>109</em>, 358-366, doi: 10.1016/j.watres.2016.11.062, 2017a.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="124"><br /> <li>Zhang, M., I. Engelhardt, J. &Scaron;imůnek, S. A. Bradford, D. Kasel, A. E. Berns, H. Vereecken, and E. Klumpp, Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils, <em>Environmental Pollution</em>, <em>221</em>, 470-479, doi: 1016/j.envpol.2016.12.018, 2017b.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="125"><br /> <li>Zhang, X., H. Lei, L. Zhu, M. Qian, G. Yadavalli, J. Wu, and S. Chen, From plastics to jet fuel range alkanes via combined catalytic conversions, Fuel, 188, 28-38, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="126"><br /> <li>Zheng, Q., Wenjie Xu, Jun Man, Lingzao Zeng, Laosheng Wu. A probabilistic collocation based iterative Kalman filter for landfill data assimilation. Advances in Water Resources. (2017). 109: 170-180.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="127"><br /> <li>Zhang, W., Jiachun Shi, Laosheng Wu. Effects of different passivators and vermicomposting on fractionations of Cu and Zn from pig manure. Journal of Zhejiang University (Agric. &amp; Life Sci.), 2017,43(6):678-685</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="128"><br /> <li>Zhang, X., T. Ren, J. Heitman, and R. Horton. 2017. Advances in heat-pulse methods: measuring near-surface soil water content. Methods of Soil Analysis Vol. 2, doi:10.2136/msa2015.0032.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="129"><br /> <li>Zhou, H., Xiuling Yu, Cheng Chen, Lingzao Zeng, Shenggao Lu, Laosheng Wu. 2017. Application of synchrotron-based X-ray microcomputed tomography and high-performance pore-scale simulations to evaluate hydraulic properties of biocharamended soil aggregates. Soil Sci. Soc. Am. J. Accepted Paper, posted 10/12/2017. doi:10.2136/sssaj2017.02.0053</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Theses/Dissertations</strong>:</p><br /> <ol><br /> <li>Edwards, Emily Claire, 2017. Assessing the groundwater contamination risk of drywell-induced stormwater infiltration using analytical and numerical methods. University of California, Davis, 222 pages.</li><br /> <li>Ransom, Katherine Marie, 2017. Bayesian and machine learning methods for the analysis of nitrate in groundwater in the Central Valley, California, USA. Dissertation, University of California, Davis, 167 pages.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Patents</strong></p><br /> <p>Liu, G., M. Wen, R. Horton, R. Ren, B.C. Si, J. Wang, and B. Li. 2017. In situ spacing-correcting heat pulse sensor and method for measuring sap flow or water flux. U.S. Patent 9638558. Date issued: 2 May 2017.</p>

Impact Statements

1. University of Minnesota (John Nieber): The results of the research are being implemented by the Minnesota Department of Transportation and the Minnesota Pollution Control Agency in assessing the credits that highway departments will get for controlling stormwater runoff in urban districts. The use of swale sideslopes are now viewed as being a resource that can help to reduce the need (or reduced size) for downstream holding ponds and raingardens. The improved model offers an opportunity to modelers to improve the features embedded in various conceptual watershed models (e.g., HSPF, SWAT, HEC-1) used by consultants and government agencies. Work remains with this model to include surface runoff, evapotranspiration, and snowmelt algorithms.

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Report Information

Participants

Majdi Abou Najm, UC Davis; Hoori Ajami, UC Riverside; Emmanuel Arthur, Aarhus University; Ebrahim Babaeian, University of Arizona; Todd Caldwell, University of Texas at Austin; Karletta Chief, University of Arizona; Maria Dragila, Oregon State University; Markus Flury, Washington State University; Shmulik Friedman, Institute of Soil, Water and Environmental Sciences; Alex Furman, Israel Institute of Technology; Horst H. Gerke, Leibniz Centre for Agricultural Landscape Research; Teamrat Ghezzehei, UC Merced; Amir Haghverdi, UC Riverside; Shoichiro Hamamoto, The University of Tokyo; Thomas Harter, UC Davis; Robert Heinse, University of Idaho; Robert Horton, Iowa State University; Jingyi Huang, University of Wisconsin Madison; Yan Jin, University of Delware; Scott Jones, Utah State University; Tamir Kamai, The Volcani Center; Thijs Kelleners, University of Wyoming; Naftali Lazarovitch, Ben-Gurion University of the Negev; Yili Lu, China Agricultural University; David Mulla, University of Minnesota; Attila Nemes, Norwegian Institute of Bioeconomy Research; John Nieber, University of Minnesota; Carlos Ochoa, Oregon State University; Tyson Ochsner, Oklahoma Statee University; Hanna Ouaknin, UC Davis; David Robinson, Centre for Ecology & Hydrology; Morteza Sadeghi, Utah State University; Elia Scudiero, UC Riverside; Manoj Shukla, New Mexico State University; Jiri Simunek, UC Riverside; Ryan Stewart, Virginia Tech; Christine Stockert, UC Riverside; Paul Stoy, Montana State University; Markus Tuller, University of Arizona; Ole Wendroth , University of Kentucky; Laosheng Wu, UC Riverside; Michael Young, University of Texas at Austin; Wei Zhang, Michigan State University; Jie Zhuang, The University of Tennessee; Jan Hopman, UC Davis.

Brief Summary of Minutes

Hoori Ajami (Chair) and Wei Zhang (Secretary)

 

January 10, 2019. Chair brought the house to order on 9:00 AM.

 

Steve Loring (Administrative Advisor, New Mexico State University) joined the meeting through video conferencing. He provided USDA update, and discussed preparation and submission of annual report as well as project renewal proposal.

 

John Nieber (University of Minnesota) led proposal discussion.

 

Jiangyi Huang (University of Wisconsin) discussed high-resolution mapping of soil moisture in cropland using remote sensing and soil moisture probes and the role of soil moisture at various scale on digital agriculture.

 

One-hour poster session was held.

 

Thijs Kelleners (University of Wyoming) presented research on coupled water, heat and solute transport in a rangeland soil, above and below-canopy turbulent fluxes in a mountain forest, and geological impact on streamflow generation in the Rocky mountains. It was found that solute transport in semi-arid rangeland soil is limited, except perhaps during spring snowmelt.

 

Business meeting on 12:00-13:00 PM. Next annual meeting will be held on January 2-3, 2020 at Las Vegas. Ryan Stewart (Virginia Tech) was elected as Secretary. 

 

Michael Young and Todd Caldwell (The University of Texas at Austin) reported work on regional scale landscape impacts in Texas from energy development, assessment of Arctic tundra permafrost, structure from motion photogrammetry of desert ecosystems, integrated assessment modeling of natural/human environments, calibration and validation activities for NASA SMAP satellite, and sensor evaluation.

 

Robert Horton (Iowa State University) presented sensor research for measurement of bulk density, soil water content, thermal properties, and hydraulic properties. Particular attention was made on in situ correction of heat pulse sensor spacing.

 

Ryan Stewart (Virginia Tech) discussed dynamic controls on soil preferential flows, specifically the role of soil structure on transport of neonicotinoid pesticide and the simulation of preferential flow, infiltration, and overland flow in shrink-swell soils.

 

Thomas Harter’s group (University of California Davis) reported their work on the irrigation demand calculator (IDC) validation. IDC is sensitive to soil type, soil parameterization choice, and climate scenario. Irrigation and nitrogen management on almond production was discussed.

 

Karletta Chief (University of Arizona) discussed the extension programs on water management and policy, mining and environmental impacts, and tribal watershed hydrology. NSF NRT INDIGE-FEWS: Indigenous food, energy & water systems, and arsenic and lead in sediment and agricultural soil along the San Juan River on the Navajo Nation one year after the Cold King Mine Spill were discussed.

 

Hoori Ajami’s group (University of California Riverside) reported the progress on development of a semi-distributed hydrologic modeling framework for catchment scale simulations, and showed that the Soil Moisture and Runoff Simulation Toolkit (SMART) is computationally efficient. They also used multiple approaches for disaggregating soil moisture to finer spatial resolutions, and quantified uncertainty of semi-distributed hydrologic model simulations. Groundwater recharge through the critical zone to the groundwater was also discussed.

 

Scott Jones’s group (Utah State University) reported work on soil sensing depth disparity, sensor development, the need for soil moisture sensor standards, soil parametrization in land surface models, and soil moisture monitoring and forecast network for improved water resource management. An analytical approach to calculate surface water flux from near-surface soil moisture data was presented.

 

Markus Tuller and Ebrahim Babaeian’s group (The University of Arizona) discussed project on hydraulic and aeration properties of soilless greenhouse substrate mixtures, and unmanned aircraft system (UAS) for high resolution mapping of soil moisture for precision agriculture applications.

 

Ole Wendroth (University of Kentucky) reported their work on exploring spatial variability of soil properties for water management, including co-regionalizing soil clay content, mapping zone delineation, pedo-transfer functions at the field scale, and scale decomposition of soil hydraulic conductivity.

 

Meeting closed for the day at 5:30 PM.

 

January 11 2019. Chair brought the house to order at 9:00 AM.

 

Wei Zhang (Michigan State University) discussed research on emerging contaminants in soil, water and plant systems, including internalization mechanisms of silver nanoparticles by plants, and antibiotic resistance genes and microbiome in soils exposed to antibiotics load.

 

Markus Flury and Joan Wu (Washington State University) reported work on stormwater and land use management, colloid and surface properties of biochar, interfacial dynamics at aqueous-NAPL interfaces, habitability of Martian environments by Atcadama Desert Experiment, and microplastics and biodegradable mulch in soil environment.

 

Yan Jin (University of Delaware) discussed research on quantification of colloids and colloidal carbon in environmental systems, coupling of colloid/organic carbon behaviors and redox oscillations, preferential flow paths as biological hotspots, biophysical processes in the rhizosphere, and colloid/bacteria attachment/detachment on/from rough surfaces.

 

Manoj Shukla’s group (New Mexico State University) reported their work on data logger machine learning algorithms, ground water salinity, and brackish water for sustainable use.

 

Maria Dragila and Carlos Ochoa (Oregon State University) discussed work on sandy soil hydrology, soil solarization for pathogen and weed disinfection, soil aeration, and land use-environment relationships in rangeland and agriculture systems.

 

Jirka Simunek (University of California Riverside) reported on research and activities on HYDRUS including 6^th HYDRUS Conference in Japan and 5 short courses, hydrological applications using HYDRUS (e.g., freshwater, freshwater recharge and salt/fresh water interfaces, and HYDRUS Package for MODFLOW), fate and transport of various substances (carbon nanotubes, viruses, and explosives), agricultural (irrigation) applications, and new HYDRUS development.

 

Laosheng Wu (University of California Riverside) discussed leaching requirements in irrigated crop lands, how to determine leaching fraction for deficit, drip, micro-sprinkler and alternative row irrigation methods. A web tool for soil salinity and leaching management was also presented.

 

Tyson Ochsner (Oklahoma State University) reported research on groundwater recharge, large-scale soil moisture monitoring, and new applications for soil moisture information. New open educational resource was also presented.

 

Naftali Lazarovitch (Ben-Gurion University of the Negev) discussed water and solute balances for irrigation using lysimeters, and found that the lysimeter lower boundary condition affects the solute distribution in the soil, suction cup can be used for soil solution chemistry measurement and a need for transient and spatial sampling of soil and plants.

 

Tamir Kamai (Institute of Soil, Water, and Environmental Sciences) reported novel methods of using pressure waves in porous media for increasing flow and transport by creating significant local pressure gradients and abrupt pressure changes in soil water.

 

Teamrat Ghezzehei (University of California Merced) discussed the role of soil water retention characteristics on aerobic microbial respiration, and introduced a model that can predict moisture-sensitivity function without the need for measured respiration rates over wide range of moisture status.

 

Elia Scudiero (University of California) presented work on precision agriculture research including dynamic management zones to improve irrigation scheduling and integrating soil and plant spatial information for time-specific precision agriculture.

 

Meeting closed at 5:00 pm.

Accomplishments

<p><strong>Short-term Outcomes</strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p>University of Arizona (Markus Tuller and Ebrahim Babaeian): Modified the ParSWMS parallelized code for solving 3-D water and solute transport, resolved computational issues and adapted the code for &ldquo;Ocelote&rdquo;, the University of Arizona&rsquo;s high-performance computing cluster, and the modified code will be made available pending additional testing; Developed a framework for delineation of dust emission source zones based on satellite remote sensing observations; Developed approach to quantify soil vapor sorption hysteresis in collaboration with Aarhus University (Emmanuel Arthur); Conducted extensive field experiments with a one-of-a-kind robotic phenotyping scanner to develop physical relationships between SWIR reflectance and actual evapotranspiration in collaboration with Utah State University (Morteza Sadeghi and Scott Jones); Developed a framework to generate high-resolution plant available moisture maps from unmanned aircraft system (UAS) observations and ground soil moisture measurements to aid precision irrigation management in collaboration with Utah State University (Morteza Sadeghi and Scott Jones); Collaborated with Utah State University (Morteza Sadeghi and Scott Jones) to develop a new analytical model for estimation of land surface net water flux from near-surface soil moisture observations.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Hoori Ajami): Extended the functionality of the semi-distributed model (SMART) model to the catchment scale; Developed a new approach for disaggregating sub-basin scale soil moisture to fine resolution; Performing multi-objective assessment of SMART simulations across a range of catchments in Australia using discharge and remotely sensed evapotranspiration and soil moisture products, in collaboration with Ashish Sharma University of New South Wales; Developed new approaches for quantifying uncertainty of conceptual ecohydrologic models using remotely sensed vegetation products, in collaboration with Lucy Marshall University of New South Wales.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Jirka Simunek): Continued to expand the capabilities of the HYDRUS modeling environment by developing specialized modules for more complex applications that cannot be solved using its standard versions. A range of applications published in 2018 included: hydrological applications, the use of HYDRUS models to evaluate various irrigation and fertigation problems in agricultural applications, and fate and transport of various substances (carbon nanotubes, viruses, explosives).</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Laoshen Wu): Developed numerical and data analysis methods for predicting gas, water and solute transport in porous media and in groundwater; Evaluated management practices to maximize salinity leaching and minimize nitrate leaching in irrigated croplands.</p><br /> <p>&nbsp;</p><br /> <p>University of Delaware (Yan Jin): Continued progress on quantifying the effects of rhizobacteria on water physical and hydrological properties using novel experimental techniques and new modeling approaches; Demonstrated that small colloids (&lt; 0.45 &micro;m), which are conventionally considered as part of the dissolved fraction, are quantitatively significant in water samples from multiple field sites as well as in laboratory studies; Demonstrated that soil organic carbon has size-dependent properties and biological activity; Designed and used a two-dimensional setup to study preferential flow pathways as biological hotspots; Measured flow and colloid/bacteria deposition behaviors on surfaces of varied roughness via sessile drop evaporation.</p><br /> <p>&nbsp;</p><br /> <p>Iowa State University (Robert Horton) and North Carolina State University (Joshua Heitman): Developed an empirical model to determine soil thermal diffusivity from texture, bulk density and degree of water saturation; Developed a heat pulse probe method to estimate water content and bulk density simultaneously; Determined in-situ unsaturated soil hydraulic conductivity at a fine depth scale with heat pulse and water potential sensors; Demonstrated that an in situ probe‐spacing‐correcting thermo‐TDR sensor can measure soil water content accurately; Demonstrated that accounting for soil porosity improves a thermal inertia model for estimating surface soil water content.</p><br /> <p>&nbsp;</p><br /> <p>New Mexico State University (Manoj Shukla): Demonstrated that irrigation with brackish groundwater and desalination concentrate increases number of flowers but continued irrigation decreases chile pepper yields; Demonstrated that desalinated brackish groundwater and RO concentrate can be used to grow halophytes; Demonstrated that RO irrigation will increase soil salinity, therefore, RO irrigation should only be applied until vegetation establishment and in non-agricultural areas; Water and nitrogen management can be improved using numerical models; Shared results with stakeholders.</p><br /> <p>&nbsp;</p><br /> <p>Oklahoma State University (Tyson Ochsner). Key outcomes of this project during this reporting period were advances in scientific knowledge on estimating drainage rates and nutrient leaching from the root zone under crops using two methods: 1) soil water balance calculations and suction cup samplers and 2) automated equilibrium tension lysimeters. This new knowledge was generated by the project team and shared with audiences of researchers and stakeholders through peer-reviewed journal publications.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Maria Dragila): For sandy soil water cycle study, completed field experiments to assess irrigation efficiency, initiated data analysis, graduated 2 MS students, and discussed with potential co-PIs for a project on deep drainage nitrate transport from sandy soil agricultural fields; for vadose zone aeration, completed two manuscripts associated with soil and vadose zone aeration; completed field work and initiated data analysis for soil solarization study.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Carlos Ochoa): Installed three additional stations to monitor soil moisture, temperature, and conductivity fluctuations in under-canopy and inter-canopy locations in juniper woodlands of central Oregon; Installed one station to monitor soil moisture, temperature, and conductivity fluctuations in a sage steppe rangeland location in eastern Oregon; Installed instrumentation to monitor soil moisture, temperature, and conductivity fluctuations in a riparian area, a meadow pasture, a non-irrigated pasture, and an irrigated pasture in western, Oregon; Performed data collection and analyses of soil physical properties from the three sites mentioned above.</p><br /> <p>&nbsp;</p><br /> <p>Nevada, Desert Research Institute (Markus Berli): Developed a model to describe the relationship between soil hydrophobicity and infiltration; Developed a model to describe water infiltration, redistribution and evaporation for arid soil; Developed a model to simulate post-fire stream and debris flow.</p><br /> <p>&nbsp;</p><br /> <p>North Dakota State University (Aaron Daigh and Francis Casey): Evaluated the temporal response of soil microbial communities to natural cycles of water and heat transfer in agricultural fields of varying soil disturbance levels; Evaluated a thermal-desorption method, used for remediating oil-contaminated soils, effects on soil physical properties and partitioning of the surface energy balance; Evaluated hydrophobic capillary barriers to limit resalinization of remediated brine-spill soil; Developed new in-situ methods to harvest brine spill salts from the soil surface using engineered wicking materials. Limitations of the method were defined and long-term effects to crop health and soil microbial communities quantified; Evaluated the fate of halogenated 17&beta;-estradiol and estrone in the environment.</p><br /> <p>&nbsp;</p><br /> <p>Washington State University (Markus Flury and Joan Wu): Demonstrated that in the driest places on earth there lives a metabolically active, microbial community; Showed the biodegradable plastic mulches have no negative impacts on soil quality; Showed that earthworms will pull plastic mulch into their burrows, thereby distributing plastic in the soil profile; Tested methods to extract nano- and microplastics from soils, and showed that currently used methods are ineffective in quantitatively extracting nano- and microplastics from soils; Through a simulation study, we evaluated fuel reduction treatment effects in a national forest, and showed that fuel reduction treatments, such as thinning and prescribed burns to treated hillslopes, may lead to an increase in water yield and significant alterations in hydrological processes.</p><br /> <p>&nbsp;</p><br /> <p>University of Texas at Austin (Todd Caldwell and Michael Young): Created new conceptual models for evolution of ice-wedge polygons in thermokarst environments in the Alaskan tundra, near Prudhoe Bay; Develop numerical models to simulate temperature changes in ice-wedge polygons through a year of simulation period.&nbsp; The results closely matched field data collected at the site, indicating that our conceptual understanding of thermal build up is reasonable representation of natural site conditions; The CS655 soil water content sensor was tested at a soil observation network in Texas; data were used for the NASA SMAP satellite mission.&nbsp; Calibration of the sensor reduced the error of calibration to below RMSE of 0.02 m³ m^-3; Creation of soil moisture validation data sets at multiple scales (1, 3, 9 and 36 km) for integration in real time into algorithm development and retrieval validation with NASA, the European Space Agency, The Japan Aerospace Exploration Agency. The development of upscaling and downscaling routines using both simple (spatial averaging) and advanced machine learn techniques; Different observation networks and watersheds are being used in US to understand landscape and biome scale processes. A broad survey of researchers and end users indicate several challenges in ensuring that data being collected at these sites are used in Earth system models and that the models are incorporating the multiple lines of data being collected; Significant energy development in Texas (and elsewhere) is leading to degraded landscapes and species habitats. Using the Eagle Ford energy region of South Texas as a test site, we assessed landscape changes with time from 2006-2014, when hydraulic fracturing technologies were applied for oil and gas exploration. Results indicate an increased area of landscape impact from ~95 km2 to 225 km2 during the study period. Some revegetation occurred during the study period.</p><br /> <p>&nbsp;</p><br /> <p>University of Wyoming (Thijs Kelleners). Above- and below-canopy eddy covariance data from forest ecosystems were used to validate calculated canopy and surface energy balances generated by the GEOtop watershed model; Progress was made towards determining hillslope subsurface hydraulic parameters using time-lapse electrical resistivity tomography data; Soil solute transport was added to an existing soil-plant-atmosphere numerical model describing coupled water flow and heat transport in snow and soil.</p><br /> <p>&nbsp;</p><br /> <p>Texas A&amp;M University (Binayak Mohanty). Research effort has summarized available soil moisture and soil hydraulic property estimation using in situ and satellite-based sensors (Mohanty et al., 2017; Mohanty, 2013). We developed the new concept of watershed-scale subsurface connectivity (Kim and Mohanty, 2016, 2017) using probabilistic soil moisture thresholds between adjacent pixels to describe the spatial patterns of soil moisture as well as Bayesian model averaging for addressing water balance (including stream flow, ET, recharge, and root zone moisture) across hydrologic watersheds. We investigated land surface physical controls for multi-scale soil moisture distribution (Gaur and Mohanty, 2016, 2018) in various landscapes and hydroclimates and developed new physical control based scaling algorithms to downscale satellite soil moisture data (Gaur and Mohanty, 2018). Our team developed novel space-time modeling for soil moisture (Chen et al., 2017) as well as non-parametric modeling scheme (Shin et al., 2018) for linking precipitation and soil moisture spatio-temporal distributions. We formulated first-of-its-kind nonstationary geostatistical framework for fusing multi-platform (insitu, air-borne, and space-borne) soil moisture estimates and generating more reliable multi-scale soil moisture products (Kathuria et al., 2019a,b). In addition, we have developed a two-stage machine learning scheme for gap filling in satellite soil moisture data in space and time (Mao et al., 2019). Using Soil Moisture Active Passive (SMAP) satellite, we discovered the time stable features and minimum number of soil moisture ground samples necessary for calibration/validation at satellite footprint-scale as well as estimating watershed-mean soil moisture with high accuracy (Singh et al., 2019 a,b). We have investigated local-scale coupled hydraulic and thermally-driven unsaturated flow processes in the shallow subsurface and developed novel upscaling scheme to describe field-scale land-atmosphere phenomenon across diurnal to longer time scales (Sviercoski et al., 2018). Using field campaign data from Southern Great Plains region, our study showed new ways to derive transfer functions for soil water retention properties using landscape features and soil thermal properties (Bayat et al., 2019). In addition to these experimental, modeling, scaling, data fusion and conceptual soil moisture and hydraulic parameter development efforts, we participated in national and international review, synthesis, and writing vision papers, setting the stage for next-generation soil hydrologic research leading to its applications in land surface modeling leading to earth systems modeling (Rahmati et al., 2018, Fan et al., 2019).</p><br /> <p>&nbsp;</p><br /> <p>Montana State University (Paul C. Stoy): Measured the surface-atmosphere exchange of water, energy, and CO2 using the eddy covariance system at a montane grassland and organized existing eddy covariance observations from flood and pivot-irrigated and dryland cropping sequences; Developed approaches to simulate the impacts of large-scale transitions away from baresoil toward alternate cropping sequences on regional climate processes in the Northern Plains using 4 km convection-permitting Weather Research and Forecasting (WRF) model runs; Demonstrated that the 2017 Northern Plains drought was preceded by anomalously low likelihood of convective precipitation but convective precipitation itself has become far more likely over the past four decades &ndash; by up to 40% during May and June; Derived a simple model for the partitioning of solar radiation into direct and diffuse components.</p><br /> <p>&nbsp;</p><br /> <p>Virginia Tech (Ryan Stewart): Developed a new conceptual model to mechanistically describe how mineral water repellency regulates water vapor sorption and exchange in soils; Demonstrated that wildfires in southern Appalachian Mountain forests can induce soil water repellency and reduce infiltration rates for at least one year; Developed new low-cost and open-source methods (using Arduino-based sensors) to characterize water turbidity and soil microbial respiration and activity; Developed a numerical model to describe the effects of installation of permeable porous tree pit coverings on water fluxes within urban environments; Developed an analytical model that differentiates between overland flow mechanisms that is applicable to urban and reference soil profiles.</p><br /> <p>&nbsp;</p><br /> <p>University of Wisconsin Madison (Jingyi Huang): We worked with farms in Central Sands, Wisconsin on monitoring and mapping the soil water dynamics over the growing seasons from 2016 to 2018. We demonstrated that irrigation management can be improved by using soil moisture probes and remote sensing platforms; We worked with NRCS, Wisconsin on monitoring and mapping soil organic carbon stock dynamics across the whole Wisconsin from 1850 to 2050. We demonstrated that land use change, improved agricultural management and climate change are the main drivers that affect the soil organic carbon stocks; We mapped the within-field variation of soil water dynamics in Central Sands, and identified areas of irrigation inefficiencies for future improvement; We shared results with stakeholders.</p><br /> <p>&nbsp;</p><br /> <p>Michigan State University (Wei Zhang):&nbsp; Investigated the plant uptake and in-plant transformation of pharmaceuticals; Investigated the effect of overhead and soil surface irrigation on pharmaceutical residue levels in greenhouse lettuce, showing that overhead irrigation resulted in greater pharmaceutical residue levels in lettuce shoot; Assessed whether pharmaceutical exposure through soils and irrigation water could influence the survival of human pathogens in vegetables, due to competition between native bacteria and invading pathogens; Investigated the role of stomata to the internalization of silver nanoparticles into plant leaves, using Arabidopsis thaliana as model plants; Investigated novel ZnO nanowires as catalysts for photodegradation of cephalexin; Investigated metal-organic frameworks materials for sorption of Se(IV) and Se(VI); Investigated the effect of biochar amendment in soils on zinc uptake by wheat and rice; Continued collaboration with researchers in China.</p><br /> <p>&nbsp;</p><br /> <p><strong>Outputs</strong></p><br /> <p>&nbsp;</p><br /> <p>University of Arizona (Markus Tuller and Ebrahim Babaeian): Research results were disseminated in collaboration with various involved groups through 8 peer-refereed international journal publications and book chapters, and 4 conference contributions.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Hoori Ajami): Published 4 journal articles related to groundwater recharge processes, quantifying uncertainty in ecohydrologic models, catchment scale application of the new semi-distributed modeling framework, and development of a new hybrid approach for disaggregation of coarse resolution soil moisture to fine resolution; Wrote the hydrologic assessment section of California&rsquo;s Fourth Climate Change Assessment report for the Desert inlands region (<a href="http://www.climateassessment.ca.gov/regions/docs/20180827-InlandDeserts.pdf">http://www.climateassessment.ca.gov/regions/docs/20180827-InlandDeserts.pdf</a>); journal article is currently under review and 5 conference abstracts were published in 2018; 3 invited public presentations as part of California&rsquo;s Fourth Climate Change Assessment report and Riverside County Ag Expo; Taught 2 upper division undergraduate course regarding principles of Groundwater science (4 units), and Spatial analysis and remote sensing for environmental sciences (4 units); Served on 2 PhD dissertation committee and 2 PhD qualifying exams; Served as Associate Editor of California Agriculture and Hydrological Sciences Journals.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Jirka Simunek). Research findings were disseminated via refereed journal publications, conference proceedings, and a number of presentations at national and international meetings (see the publication section below). HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects, which in turn have been published in peer-reviewed journals.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Laosheng Wu): Research results were disseminated through peer-refereed international journal publications, presentations, and classroom teaching.</p><br /> <p>&nbsp;</p><br /> <p>University of Delaware (Yan Jin): Research results were disseminated in collaboration with various involved groups through 6 peer-refereed international journal publications and 21 invited and volunteered conference contributions.</p><br /> <p>&nbsp;</p><br /> <p>Iowa State University (Robert Horton) and North Carolina State University (Joshua Heitman): Research results were disseminated in collaboration with various involved groups through peer-refereed publications.</p><br /> <p>&nbsp;</p><br /> <p>University of Kentucky (Ole Wendroth): Research results were disseminated in 6 scientific peer-reviewed journal articles, during field days, and commodity group meetings, in 1 extension publication, and to audiences at scientific meetings (Kentucky Water Resources Research Institute Meeting, Congress of the International Union of soil Science Congress, and American Society of Agronomy meeting).</p><br /> <p>&nbsp;</p><br /> <p>New Mexico State University (Manoj Shukla): Seven peer-reviewed manuscripts were published or accepted for publication; Two invited talks to China Agricultural University, Beijing, China in June 2018; Four manuscripts submitted for publication to peer reviewed Journals; Mentored 2 MS and 5 PhD students as chair and 5 other graduate students as committee member; Graduated 1 MS student.</p><br /> <p>&nbsp;</p><br /> <p>Oklahoma State University (Tyson Ochsher): Paper describing soil water dynamics and nitrate leaching under corn&ndash;soybean rotation, continuous corn, and kura clover was published in Vadose Zone J.; Paper describing nitrate leaching in soybean rotations without nitrogen fertilizer was published in the journal Plant and Soil.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Maria Dragila): Presented results to growers at Columbia Basin Soil Health Potato Commission Conference for the sandy soil water cycle study; Published two manuscripts for the vadose zone aeration study; Presented results to growers and extension agents at North Willamette Research and Extension Center Solarization Workshop and published article in The Organic Farmer Magazine (west coast publication) for the soil solarization study.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Carlos Ochoa): Conference contribution presenting findings related to soil moisture differences at different depth in under-canopy and inter-canopy locations in juniper dominated landscapes; Conference contribution presenting soil moisture monitoring in three long-term, watershed-scale, study sites being established in western, central, and eastern OR locations.</p><br /> <p>&nbsp;</p><br /> <p>Nevada, Desert Research Institute (Markus Berli): Our publications focused on developing and validating models to describe the water dynamics of arid soils and their impact on desert hydrology.</p><br /> <p>&nbsp;</p><br /> <p>North Dakota State University (Aaron Daigh and Francis Casey): Research findings were disseminated via 12 publications in peer-reviewed journals, 11 research reports and 7 conference abstracts and presentations.</p><br /> <p>&nbsp;</p><br /> <p>Washington State University (Markus Flury and Joan Wu): Published our research results in peer-reviewed journals and presented the research results in national and international conferences (Soil Science Society Annual Meeting; European Geoscience Union), and invited talks in China and Germany. The highlight was a publication in the Proceedings of the National Academy of Sciences, which has led to comprehensive news coverage in Europe, USA, and South America.</p><br /> <p>&nbsp;</p><br /> <p>University of Texas at Austin (Todd Caldwell and Michael Young): Research findings were disseminated via refereed journal publications and presentations at local, national and international meetings.</p><br /> <p>&nbsp;</p><br /> <p>University of Wyoming (Thijs Kelleners): 5 journal articles were published in 2018; 5 courses were taught: Soil Physics Lecture (3 credits), Soil Physics Laboratory (2 credits), Agroecology Capstone (1.5 credits), Modeling Flow and Transport (4 credits), and Forest and Range Soils (3 credits).</p><br /> <p>&nbsp;</p><br /> <p>Montana State University (Paul C. Stoy): Published 14 manuscripts (two in open review) on topics including snow and environmental physics including the role of landcover change away from bare soil (summer fallow) on the regional climate of the Northern Plains; Gave 4 conference presentations and 6 invited presentations and contributed to eight conference presentations by postdoctoral research scientists and graduate students; Provided input to popular press articles in Science, Massive Science and The Furrow by John Deere.</p><br /> <p>&nbsp;</p><br /> <p>Virginia Tech (Ryan Stewart): Research findings were disseminated via 2 publications in peer-reviewed journals and 5 conference abstracts and presentations.</p><br /> <p>&nbsp;</p><br /> <p>University of Wisconsin Madison (Jingyi Huang): Two peer-reviewed manuscripts published or accepted for publication; Two oral presentations (one invited) in World Soil Congress, Rio de Janeiro, Brazil, 2018; Three manuscripts submitted for publication to peer-reviewed journals; 1 PhD as main advisor and 1 PhD as committee member.</p><br /> <p>&nbsp;</p><br /> <p>Michigan State University (Wei Zhang): Published 12 journal articles, gave 8 presentations (5 invited) in national and international conferences, delivered 8 invited seminars, edited a special issue &ldquo;Advancing soil physics for securing food, water, soil and ecosystem services&rdquo; in Vadose Zone Journal, and served as Secretary General for International Symposium on Agro-Environmental Quality, Nanjing, China, November 2-5, 2018.</p><br /> <p>&nbsp;</p><br /> <p><strong>Activities</strong></p><br /> <p>&nbsp;</p><br /> <p>University of Arizona (Markus Tuller and Ebrahim Babaeian)</p><br /> <p>(1) Adoption and Modification of ParSWMS (Mohammad Gohardoust, Horst Hardelauf, Asher Bar-Tal, and Markus Tuller). Simulation of three-dimensional water flow and solute transport in containerized variably saturated soilless substrates with complex hydraulic properties and boundary conditions necessitates high-resolution discretization of the spatial domain, which commonly leads to several million nodes requiring numerical evaluation. Even today&rsquo;s computational power of workstations is not adequate to tackle such problems within a reasonable timeframe. Hence, parallelization of the numerical code and utilization of supercomputers are required. The previous version of ParSWMS (Hardelauf et al., 2007), which is the parallelized version of SWMS-3D (Simunek et al., 1995) solves porous media water flow and solute transport equations considering one solute at a time and a linear adsorption isotherm. The code was modified to accommodate nonlinear solute adsorption and to support multi-species solute simulations. Computational issues were resolved and the code was adapted to run on high-performance computing clusters.</p><br /> <p>&nbsp;</p><br /> <p>(2) Remote Sensing of Earth Surface Processes. In collaboration with Utah State University (Morteza Sadeghi and Scott Jones) we continued to extensively work on the development of novel measurement and remote sensing techniques for characterization of largescale near surface processes and basic soil properties. Below are a few research highlights accomplished in 2018.</p><br /> <p>&nbsp;</p><br /> <p>(3) Application of Satellite Remote Sensing for Delineation of Dust Source Zones (Mohaddese Effati, Mohammad Gohardoust, Ebrahim Babaeian and Markus Tuller): Saline playas in arid and semiarid regions of the world are significant sources of unconsolidated sediments susceptible to aeolian transport. This causes ecosystem degradation, accelerated desertification and frequent dust storms, causing respiratory diseases and other health problems. We developed a framework for delineation of dust source zones and estimation of dust storm occurrence probability based on remotely sensed land surface properties (i.e., soil moisture and vegetation cover), soil texture, climate characteristics (i.e., wind speed) and ground visibility measurements to inform possible remediation measures. Observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) are utilized to determine the Normalized Difference Vegetation Index (NDVI) and to estimate surface soil moisture with a recently introduced optical trapezoid model. The soil textures extracted from the SoilGrids database and wind speeds obtained from local weather stations together with the estimated surface soil moisture where found to be highly correlated with dust emission probability.</p><br /> <p>&nbsp;</p><br /> <p>(3) Unmanned Aircraft System Observations for Estimation and Monitoring of Soil Moisture Variability for Agricultural Water Management (Ebrahim Babaeian, Richard Ward, Maria S. Newcomb, Morteza Sadeghi, Scott Jones, and Markus Tuller): Knowledge about the variability of soil moisture (SM) and plant available water (PAW) is crucial for precision agricultural water management. Recent advances in unmanned aircraft system (UAS) and electromagnetic in situ soil moisture sensing technology provide powerful means for irrigation management. We developed a new framework combining remote UAS and satellite observations with ground-based soil moisture measurements and numerical modeling to provide decision support for farm-scale precision irrigation management. We introduced a new trapezoidal space confined by remotely-sensed near infrared transformed reflectance (NTR) and normalized difference vegetation index (NDVI) data for estimation and mapping of SM and PAW variability.</p><br /> <p>&nbsp;</p><br /> <p>(4) A New Analytical Model for Estimation of Land Surface Net Water Flux from Near-Surface Soil Moisture Observations (Morteza Sadeghi⁠, Markus Tuller, Arthur W. Warrick⁠, Ebrahim Babaeian, Kshitij Parajuli, Mohammad R. Gohardoust, and Scott B. Jones): The accurate determination of land surface water fluxes at various spatiotemporal scales remains a challenge in hydrological sciences. It is intuitive that land surface net water flux (i.e., infiltration minus evapotranspiration) directly affects near-surface soil moisture. However, there exists no hydrological model suitable to calculate net water flux based on measured near-surface soil moisture data. This is a consequence of the mathematical structure of existing models that use &lsquo;boundary conditions&rsquo; to determine &lsquo;internal conditions&rsquo;, whereas what is needed is a model amenable to use near-surface soil moisture data (an internal condition) to determine the surface water flux (a boundary condition). To pursue the idea of utilizing remotely-sensed or in situ (i.e., sensor networks) near surface soil moisture data for estimation of net water flux, we derived an analytical model via inversion of Warrick&rsquo;s 1975 analytical solution to the linearized Richards&rsquo; equation for arbitrary time-varying surface flux boundary conditions. A major advantage of the new model is that it does not require calibration, which provides an unprecedented opportunity for large scale estimation of land surface net water flux using remotely sensed near-surface soil moisture observations.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Hoori Ajami): Continue on development of the SMART model by adding new functionalities; Adding new uncertainty quantification framework to SMART, in collaboration with Mojtaba Sadegh Boise State University.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Jirka Simunek): In 2018, we offered two- or three-day short courses on how to use HYDRUS models at a) Czech University of Life Sciences, Prague, Czech Republic, b) Colorado School of Mines, Golden, CO, c) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China, d) Tokyo University of Agriculture and Technology, Department of Ecoregion Science, Tokyo, Japan, e) WASCAL Headquarters, Accra, Ghana, NC. About 150 students participated in these short courses.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Laosheng Wu): Gave presentations to various academic and on-academic groups. &nbsp;Working on the following on-going projects.</p><br /> <p>Decision Support for Water Stressed FEW Nexus Decisions (DS-WSND). NSF INFEWS.&nbsp; Collaborator. 01/01/2018 to 12/30/2020.</p><br /> <p>Hispanic-Serving Institutions (HSI) Education Grants Program. USDA/NIFA. Co-PI. 10/01/2016 to 08/01/2020.</p><br /> <p>Optimizing Water Management Practices to Minimize Soil Salinity and Nitrate Leaching in California Irrigated Cropland. UC Division of Agri. &amp; Natural Res. PI. 03/2017-02/2019.</p><br /> <p>Enhancing site-specific turf irrigation management and developing turf deficit irrigation strategies using soil moisture sensors, smart ET-based irrigation controllers, and remote sensing. US Golf Association. Co-PI. 01/2018-12/31/2019.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p>University of Delaware (Yan Jin)</p><br /> <p>(1) We conducted measurements of water retention in several sand/soils to quantify the effects of rhizobacteria influence on water retention and evaporation using Hyprop with and with salt presence. The goal is to further evaluate the potential of this strain of bacteria in potentially alleviating drought and salt stresses on plants and to elucidate relevant mechanisms.</p><br /> <p>(2) Sampling and analyzing water and soil samples from a fresh water wetland, including three zones (upper land, transition zone, and wetland zone) for size fractionated colloid and OC concentrations, stable isotope values of C, N, and H, as well as multiple elements and environmental parameters (pH, Eh, EC, temperature, precipitation, water table depth&hellip;). The goal is to evaluate the effects of wetland hydrology (or hydroperiods) on colloid and carbon fate and transport in this redox-dynamic ecosystem.&nbsp;</p><br /> <p>(3) Conducted a laboratory study using syringe columns to measure the dynamic changes in colloid and OC concentration and composition as influenced by redox conditions.</p><br /> <p>(4) Conducted laboratory experiments using 2D chambers to demonstrate that preferential flow paths are biological hotspots where nutrients and microbial biomass tend to accumulate so that microbial activities are more intense at the interface of preferential flow paths and soil matrix.</p><br /> <p>(5) We examined wetting and de-wetting patterns of water and surfactant solution on both hydrophilic and hydrophobic surfaces and surfaces with regular and irregular roughness features; we also measured colloid attachment and detachment on these surfaces.</p><br /> <p>&nbsp;</p><br /> <p>Iowa State University (Robert Horton) and North Carolina State University (Joshua Heitman):</p><br /> <p>(1) Soil thermal diffusivity k is an essential parameter for studying surface and subsurface heat transfer and temperature changes. It is well understood that k mainly varies with soil texture, water content, and bulk density BD, but few models are available to accurately quantify the relationship. In this study, an empirical model is developed for estimating k from soil particle size distribution, BD, and degree of water saturation S. The model parameters are determined by fitting the proposed equations to heat-pulse k data for eight soils covering wide ranges of texture, BD, and S. Independent evaluations with published k data show that the new model describes the k(S) relationship accurately, with root-mean-square errors less than 0.75 x 10-7 m² s^-1. The proposed k(S) model also describes the responses of k to BD changes accurately in both laboratory and field conditions. The new model is also used successfully for predicting near-surface soil temperature dynamics using the harmonic method. The results suggest that the model provides useful estimates of k from S, BD, and soil texture.</p><br /> <p>(2) Soil bulk density (&rho;_b) and volumetric water content (&theta;) determine the volume fractions of soil solids, water and air, and influence mass and energy transfer in soils. It is desirable to monitor &rho;_b and &theta; concurrently and nondestructively. We present a heat pulse-based method for simultaneous determination of &rho;_b and &theta; from soil thermal properties. The method employs equations that relate &rho;_b and &theta; to soil volumetric heat capacity (C) and to soil thermal conductivity (&lambda;). Knowing soil texture and specific heat of soil solids a priori, a three-step calculation procedure is used to solve for &rho;_b and &theta; from heat-pulse sensor measured C and &lambda;. Laboratory evaluation on soil samples of various textures showed that the three-step method provided reliable &rho;_b and &theta; estimates at &theta; values greater than the critical water content when &lambda; started to respond significantly to &theta; change. This method provides a new way for simultaneous determination of &rho;_b and &theta; with a heat pulse sensor.</p><br /> <p>(3) Unsaturated hydraulic conductivity (K) of surface soil changes substantially with space and time, and it is of great importance for many ecological, agricultural, and hydrological applications. In general, K is measured in the laboratory, or more commonly, predicted using soil water retention curve and saturated hydraulic conductivity. In the field, K can be estimated through infiltration experiments. However, none of these approaches are capable of continuously monitoring K in-situ at fine depth scale. In this study, we propose and investigate an approach to continuously estimate fine depth-scale K dynamics under field conditions. Evaporation rate and change in water storage in a near-surface soil layer are measured with the heat pulse method. Then, water flux density at the lower boundary of the soil layer is estimated from evaporation rate, change in water storage, and rainfall or irrigation rate using a simple water balance approach. Finally, K values at different soil depths are derived using the Buckingham-Darcy equation from water flux densities and measured water potential gradients. A field experiment is performed to evaluate the performance of the proposed approach. K values at 2-, 4-, 7.5-, and 12.5-cm depths are estimated with the new approach. The results show that in-situ K estimates vary with time following changes in soil water content. The K-water content relationship is affected by depth due to the difference in bulk density. In-situ estimated K-matric potential curves agree well with those measured in the laboratory. In-situ K estimates also show good agreement with the Mualem-van Genuchten model predictions, with an average root mean square error in log10 (K, mm h-1) of 0.54 and an average bias of 0.17. The new approach provides reasonable in-situ K estimates and has potential to reveal the influences of natural soil conditions on hydraulic properties as they change with depth and time.</p><br /> <p>(4) To reduce the possibility of probe deflections, conventional thermo-time domain reflectometry (T-TDR) sensors have relatively short probe lengths (&le;4 cm). However, short probes lead to large errors in TDR-estimated soil water content (&theta;v). In this study, two new 6-cm-long probe-spacing-correcting T-TDR (CT-TDR) sensors are investigated. Compared to conventional 4-cm-long T-TDR sensors, the 6-cm-long CT-TDR sensors reduce errors in TDR-estimated &theta;v. Errors in HP-estimated &theta;v due to probe deflections are reduced when linear or nonlinear probe spacing correcting algorithms are implemented. The new 6-cm-long CT-TDR sensors provide more accurate &theta;v estimations than do the conventional 4-cm-long T-TDR sensors.</p><br /> <p>Soil thermal inertia (P), a property that controls the temporal variation of near-surface temperature, has been used to estimate surface water content (&theta;) in remote sensing studies. The accuracy of &theta; estimates, however, is affected by surface soil porosity (<em>n</em>). We hypothesize that <em>n</em> can be derived using a simple linear <em>n</em>-P relationship of a dry surface soil layer, and that accounting for <em>n</em> improves the accuracy of &theta; estimation using a P(&theta;) model. The P of a surface layer was measured by using the heat pulse method during a drying period, and the feasibility of estimating &theta; with a P(&theta;) model that included <em>n</em> was explored. The approach was also tested with published P values derived from meteorological data and MODIS data against <em>in situ</em> &theta; measurements at two field sites in Arizona, USA. The results on a partially vegetated shrubland indicated that by using the P-derived <em>n</em>, the P(&theta;) model provided more accurate &theta; estimates than by using the literature <em>n</em> values. Discrepancies between modeled &theta; and <em>in situ</em> &theta; measurements were observed at small &theta; values, which were caused in part by the fact that the modeled &theta; represented soil layers a few millimeters thick, while the <em>in situ</em> measurements represented &theta; at the 5-cm depth. The new <em>n</em>-P function has potential for estimating surface &theta; accurately using multi-scale P data on bare soils or on sparsely vegetated lands.</p><br /> <p>&nbsp;</p><br /> <p>University of Kentucky (Ole Wendroth): Mapping Zone delineation: Manuscript submitted and accepted (part of dissertation Javier Reyes); Resubmitted CAP grant research proposal to the Water in Agriculture Challenge Area was again turned down; Continued to use RZWQM2 to simulate crop growth of different crops, nitrogen management (part of dissertation Saadi Shahadha); Ongoing a four-state research project on irrigation management between Kentucky, Georgia, Alabama, and Tennessee.</p><br /> <p>&nbsp;</p><br /> <p>New Mexico State University (Shukla Manoj): Taught soil physics, advanced soil physics and environmental soil science classes; Taught a class on Natural Resources in Northwest A&amp;F University, China; Taught at summer school in Qi City, China Agriculture University; Hosted one faculty members from Jiangxi Agriculture University, one student from China Agriculture University, and another graduate student from China agriculture University started from November 2018; Field and greenhouse trips were organized to collect soil and water samples, soil moisture content, soil temperature, and other meteorological data; Experiments were planned on use of brackish groundwater and RO concentrate for looking at influence of irrigation water salinity on soil microbiological properties; Soil and plant samples were collected from Pecan orchards from New Mexico orchards to evaluate salinity induced changes in pecan physiology; Proposals were written and submitted to various Funding Agencies.</p><br /> <p>&nbsp;</p><br /> <p>Oklahoma State University (Tyson Ochsner): Objective 2 of this multi-state project was to develop and evaluate new instruments and analytical methods to connect our understanding of mass and energy transport in the vadose zone at different scales and environmental transformations. During this project period, we have analyzed, interpreted, and published new findings on the effectiveness of lysimeters and water balance approaches for understanding water and solute transport in agricultural ecosystems in the US and Brazil.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Maria Dragila): Investigating soil water relations in sandy agricultural soil to improve irrigation efficiency (Collaboration with M. Kleber and R. Qin, OSU) and continuing field and laboratory investigations associated with the evolutionary development of micro-aggregation in sandy soil; Investigating the biophysical mechanisms associated with the evolution of water repellency to uncover an effective remediation strategy (Collaboration with M. Kleber, OSU), and continuing laboratory investigations of water repellency development; Investigating the erosional evolution of microfractures in the epikarst and performing data analysis; Investigating the efficacy of using soil solarization for pest and weed disinfectation in the Pacific Northwest. (Collaboration with J. Parke and C. Mallory-Smith, OSU, and S. Dollen, Grower) and completed third and last-year of field trials and begun data analysis; Investigated how various mechanisms impact gas exchange across the interface between vadose zone and atmosphere. (Collaboration with N. Weisbrod, Ben Gurion, IL), completed data analysis and published 2 manuscripts; Investigating film flow below the detection limit of CT scans (Collaboration with PI Dorthe Wildenschild), preparing manuscript in progress and begun new set of experiments.</p><br /> <p>&nbsp;</p><br /> <p>Oregon State University (Carlos Ochoa): (1) Investigate soil water relations in irrigated pastures to assess water transport through the vadose zone and into the shallow aquifer (Collaboration with D. Godwin and S. Ates, OSU), including field and laboratory work related with soil physical properties and water transport through the unsaturated zone; (2) Investigate soil water relations in juniper-sage steppe landscapes to assess water transport through the vadose zone and into the shallow aquifer (Collaboration with T. Deboodt, OSU), including automated field data collection at multiple locations in one watershed with juniper and one where juniper was removed 13 years ago.</p><br /> <p>&nbsp;</p><br /> <p>Nevada, Desert Research Institute (Markus Berli): Developed a physically-based model to describe the relationship between soil hydrophobicity (expressed as apparent contact angle or water penetration time) and infiltration through sorptivity; Evaluated methods to measure sorptivity in the field; Worked on an improved understanding of water infiltration, redistribution and evaporation from arid soils; Validated the hydrology model KINEROS2 as a potential tool to simulate post-fire stream flow and sediment transport from watersheds in the US Southwest; Reviewed the state of knowledge on engineered nanomaterials (ENM) in soil environments.</p><br /> <p>&nbsp;</p><br /> <p>North Dakota State University (Aaron Daigh and Francis Casey). Soil temperatures, water contents, and the responses of soil microbial communities were monitored in a silty clay field plant to soybeans and subject to various levels of mechanical soil disturbance (tillage). This experiment is designed to improve our understanding of soil heat and water processes across spatial and temporal scales in agricultural fields and subsequent effects on soil biology. Surface energy balance partitioning was performed on field plots, remediated by thermal desorption, using micro bowen ratio. Water and salt transport across a hydrophobic leonardite was evaluated in the laboratory using large soil columns instrumented with three needle heat pulse probes and MPS-6 matric potential sensors. Continued to develop new methods to harvest brine spill salts from the soil surface. The use of a crystallization inhibitor ferric hexacyanoferrate and various wicking media were evaluated in the laboratory and greenhouse. The effects of soil ferric hexacyanoferrate contents on soybean and wheat plant health and soil microbial community structures were evaluated in a greenhouse study. Field-scale fate and transport of brominated estradiols as surrogates for native 17&szlig;-estradiol.</p><br /> <p>&nbsp;</p><br /> <p>Washington State University (Markus Flury and Joan Wu): Worked on water activities and water contents along an east-west transect in the Atacama desert; Worked on determining water contents in microhabitats in the Atacama desert; Conducted long-term field experiments to determine suitability of biodegradable plastic mulch; Evaluated soil quality as affected by long-term use of biodegradable plastic mulch; Conducted laboratory experiment to evaluate how earthworms interact with biodegradable plastic mulch; Tested whether earthworms will ingest biodegradable plastic mulch; Evaluated how freezing and drying cycles affect the leaching of metals from biosolids; Worked on quantifying interfacial convections at NAPL-water interfaces; Measured contact angles on colloidal biochar. Characterized colloidal properties of a variety biochar samples; Lead new group Hatch project on "Soil and Rhizosphere Processes"; Published a special section on &ldquo;Lysimeters in Vadose Zone Research&rdquo; in the Vadose Zone Journal; Organized symposium on &ldquo;Nanoparticle Fate and Transport in Soil and Groundwater Systems&rdquo; at the European Geoscience Union Annual meeting.</p><br /> <p>&nbsp;</p><br /> <p>University of Texas at Austin (Todd Caldwell and Michael Young). A numerical model is presented to test whether a hillslope diffusion approach can simulate the topographic evolution of some recently developed high-centered ice-wedge polygons south of Prudhoe Bay, Alaska. The polygons are adjacent to a highway whose construction appears to have triggered their geomorphic transition. The model is calibrated using a light detection and ranging data-set that captures both the high-centered polygons and some neighboring low-centered polygons that appear to be unaffected by thermokarst. The latter are used to represent initial conditions. Model simulations are analyzed to estimate potential fluxes of soil from polygon edges into troughs and the loss of depressional water storage during development of the high-centered polygons. Overall, a match between the topography of simulated and observed high-centered polygons suggests that diffusive hillslope processes represent a feasible mechanism driving polygon transition. Rates of soil displacement inferred from optimized simulations, moreover, are within the range previously observed in permafrost terrain with a similar climate. Direct observations of the soil velocity profile in actively transitioning polygons would help resolve whether and to what extent hillslope processes, as opposed to pure thaw-related subsidence at the polygon edges, drive the development of high-centered forms in natural systems.</p><br /> <p>&nbsp;</p><br /> <p>The goal of this research is to constrain the influence of ice wedge polygon microtopography on near-surface ground temperatures. Ice wedge polygon microtopography is prone to rapid deformation in a changing climate, and cracking in the ice wedge depends on thermal conditions at the top of the permafrost; therefore, feedbacks between microtopography and ground temperature can shed light on the potential for future ice wedge cracking in the Arctic. We first report on a year of sub-daily ground temperature observations at 5 depths and 9 locations throughout a cluster of low-centered polygons near Prudhoe Bay, Alaska, and demonstrate that the rims become the coldest zone of the polygon during winter, due to thinner snowpack. We then calibrate a polygon-scale numerical model of coupled thermal and hydrologic processes against this dataset, achieving an RMSE of less than 1.1 C between observed and simulated ground temperature. Finally, we conduct a sensitivity analysis of the model by systematically manipulating the height of the rims and the depth of the troughs and tracking the effects on ice wedge temperature. The results indicate that winter temperatures in the ice wedge are sensitive to both rim height and trough depth, but more sensitive to rim height. Rims act as preferential outlets of subsurface heat; increasing rim size decreases winter temperatures in the ice wedge. Deeper troughs lead to increased snow entrapment, promoting insulation of the ice wedge. The potential for ice wedge cracking is therefore reduced if rims are destroyed or if troughs subside, due to warmer conditions in the ice wedge. These findings can help explain the origins of secondary ice wedges in modern and ancient polygons. The findings also imply that the potential for re-establishing rims in modern thermokarst-affected terrain will be limited by reduced cracking activity in the ice wedges, even if regional air temperatures stabilize.</p><br /> <p>&nbsp;</p><br /> <p>Soil moisture sensors infer volumetric soil water content (SWC) from other properties of the bulk porous media. The CS655 water content reflectometer is a relatively new, low-frequency electromagnetic sensor that determines relative permittivity (Ka) using the two-way travel period and voltage attenuation of the applied signal along two 12-cm rods. This measured attenuation is quadratically related to bulk electrical conductivity (EC). Along with an onboard thermistor, the CS655 allows a more robust correction of propagation time and Ka, which its predecessors, the CS615 and CS616, lacked. However, with new sensors it is necessary to quantify their practical accuracy in the field. Here, we present an overview of the CS655 sensor and an evaluation under both laboratory and field conditions, using five surface soils (0&ndash;10-cm depth) in the laboratory and gravimetric samples collected in the field. Overall, a site-specific calibration using a two-term linearization of the SWC&ndash;Ka function reduced the root mean square error (RMSE) of the factory-derived SWC of 0.073 and 0.043 m³ m^&minus;3 during batch and infiltration experiments, respectively, to 0.025 and 0.028 m³ m^&minus;3. Results further indicate that a soil-specific calibration additionally reduced the RMSE to &lt; 0.02 m³ m^&minus;3. Field evaluation across the Texas Soil Observation Network found that calibration reduced the variance across the network but did not affect the arithmetic mean or the RMSE against gravimetric sampling, which remained ~0.05 m³ m^&minus;3 regardless of the SWC&ndash;Ka&ndash;EC function applied. At the regional scale, a global calibration is sufficient.</p><br /> <p>&nbsp;</p><br /> <p>Accurate soil moisture is critical to predict regional weather patterns, ecosystem status, and water resources. Many gridded products have emerged from land surface models and satellite data; however, validating such data is particular challenging. Soil moisture, for example, is highly variable in both time and space complicating our ability to upscale point measurements to satellite footprints. To this end, I built and maintain the Texas Soil Observation Network (TxSON,&nbsp;&nbsp; <a href="http://www.beg.utexas.edu/research/programs/txson">http://www.beg.utexas.edu/research/programs/txson</a>) to serve as an on-ground data product with replicated soil moisture at 1, 3, 9, and 36 km scales. This data and collaboration with NASA and the SMAP Science Team has moved soil moisture to the forefront of global hydrologic cycle.</p><br /> <p>&nbsp;</p><br /> <p>Advancing our understanding of Earth system dynamics (ESD) depends on the development of models and other analytical tools that apply physical, biological, and chemical data. This ambition to increase understanding and develop models of ESD based on site observations was the stimulus for creating the networks of Long-Term Ecological Research (LTER), Critical Zone Observatories (CZOs), and others. We organized a survey, the results of which identified pressing gaps in data availability from these networks, in particular for the future development and evaluation of models that represent ESD processes, and provide insights for improvement in both data collection and model integration.&nbsp; From this survey overview of data applications in the context of LTER and CZO research, we identified three challenges: (1) widen application of terrestrial observation network data in Earth system modelling, (2) develop integrated Earth system models that incorporate process representation and data of multiple disciplines, and (3) identify complementarity in measured variables and spatial extent, and promoting synergies in the existing observational networks. These challenges lead to perspectives and recommendations for an improved dialogue between the observation networks and the ESD modelling community, including co-location of sites in the existing networks and further formalizing these recommendations among these communities. Developing these synergies will enable cross-site and cross-network comparison and synthesis studies, which will help produce insights around organizing principles, classifications, and general rules of coupling processes with environmental conditions.</p><br /> <p>&nbsp;</p><br /> <p>Spatio-temporal trends in infrastructure footprints, energy production, and landscape alteration were assessed for the Eagle Ford Shale of Texas. The period of analysis was over four 2-year periods (2006&ndash;2014). Analyses used high-resolution imagery, as well as pipeline data to map EF infrastructure. Landscape conditions from 2006 were used as baseline. Results indicate that infrastructure footprints varied from 94.5 km² in 2008 to 225.0 km² in 2014. By 2014, decreased land-use intensities (ratio of land alteration to energy production) were noted play-wide. Core-area alteration by period was highest (3331.6 km²) in 2008 at the onset of play development, and increased from 582.3 to 3913.9 km² by 2014, though substantial revegetation of localized core areas was observed throughout the study (i.e., alteration improved in some areas and worsened in others). Land-use intensity in the eastern portion of the play was consistently lower than that in the western portion, while core alteration remained relatively constant east to west. Land alteration from pipeline construction was ~65 km² for all time periods, except in 2010 when alteration was recorded at 47 km². Percent of total alteration from well-pad construction increased from 27.3% in 2008 to 71.5% in 2014. The average number of wells per pad across all 27 counties increased from 1.15 to 1.7. This study presents a framework for mapping landscape alteration from oil and gas infrastructure development. However, the framework could be applied to other energy development programs, such as wind or solar fields, or any other regional infrastructure development program.</p><br /> <p>&nbsp;</p><br /> <p>University of Wyoming (Thijs Kelleners). We continue to maintain a state-wide soil moisture network for drought monitoring in rangelands (consisting of 17 sites). This is a collaboration with Ginger Paige, a hydrologist at the University of Wyoming. We are monitoring five snow-dominated experimental catchments in the Rocky Mountains. The focus is on the role of the subsurface in transforming snowmelt into streamflow. Geophysical measurements are combined with hydrological monitoring and hydrological modeling. A sixth site will be added in 2019. This is a collaboration with Andrew Parsekian, a hydro-geophysicist at the University of Wyoming.</p><br /> <p>&nbsp;</p><br /> <p>Texas A&amp;M University (Binayak Mohanty): Develop fundamental understanding of spatio-temporal variability and multi-scale soil hydrologic processes in various hydroclimatic conditions; Collect multi-scale field data on soil moisture and soil hydraulic properties using insitu and remote sensing tools; Design new data analysis, modeling, and data assimilation/ fusion platforms at multiple space-time scales; Develop adaptive upscaling and downscaling tools to generate multi-scale data products for various hydrologic and environmental applications.</p><br /> <p>&nbsp;</p><br /> <p>Montana State University (Paul C. Stoy): Synthesized observations of sensible and latent heat flux during snowmelt events to simplify the treatment of these processes in snowmelt models; Synthesized observations of climate extremes in the southeastern U.S. and observations of mean climate and extreme climate events in the Northern Plains to provide a baseline for regional climate modeling activities; Synthesized observations of carbon dioxide fluxes from tropical ecosystems including approaches for understanding the reasons that the surface energy balance as measured by eddy covariance remains unclosed and approaches to measure and estimate the flux of isoprene and methane from tropical ecosystems to the atmosphere; Described the means by which ongoing land cover changes in the Northern Plains interact with different elements of the food-energy-water nexus.</p><br /> <p>&nbsp;</p><br /> <p>Virginia Tech (Ryan Stewart). We performed and completed a laboratory experiment in which water repellency was induced to varying degrees in two model minerals (kaolinite and montmorillonite). We then quantified vapor sorption isotherms for the treatments, allowing us to quantify water repellency effects on water vapor sorption and exchange in soils. We collected and analyzed data from two field sites in southern Appalachian Mountain forests that were burned by wildfires in November 2016. Over a fourteen month period, we collected repeated measurements of soil water content, infiltration rates, and water drop penetration times, allowing us to quantify relationships between soil water content, repellency and infiltration. We performed a series of modeling exercises to understand the effects of urbanization on soil properties. In one study, we examined the role of permeable pavements on water fluxes within urban environments. We are also developing a modeling framework to compare hydrological processes (e.g., runoff, infiltration, drainage) in urban versus reference soil profiles. We collected samples and data to evaluate whether low-intensity prescribed fires affect soil aggregate stability, soil nutrient status, or water quality (e.g., dissolved organic carbon, turbidity) in a first-order forested watershed.</p><br /> <p>&nbsp;</p><br /> <p>University of Wisconsin Madison (Jingyi Huang): Taught soil physics at the graduate level at University of Wisconsin-Madison; Soil samples, soil and geophysical surveys conducted in various regions in Wisconsin to characterize the spatial and temporal variations in soil water and other properties; Meetings with various growers in Wisconsin on the application of proximal and remote sensing technologies in soil and land resources management.</p><br /> <p>&nbsp;</p><br /> <p>Michigan State University (Wei Zhang): Fundamental research on environmental processes and impacts of emerging contaminants (including pharmaceuticals such as antibiotics, engineered nanoparticles, and antibiotic resistance genes) in soil, water and plant systems; International collaboration in basic agricultural and environmental sciences.</p><br /> <p>&nbsp;</p><br /> <p><strong>Milestones</strong></p><br /> <p>&nbsp;</p><br /> <p>University of Arizona (Markus Tuller and Ebrahim Babaeian): Modified ParSWMS parallelized code to include simulation capabilities for nonlinear solute adsorption and multi-species solute simulations for optimization of soilless greenhouse substrates; Developed a framework for delineation of dust emission source zones based on satellite remote sensing observations; Developed approach to quantify soil vapor sorption hysteresis; Developed a framework to generate high-resolution plant available moisture maps from unmanned aircraft system (UAS) observations and ground soil moisture measurements to aid precision irrigation management; Developed a new analytical model for estimation of land surface net water flux from near-surface soil moisture observations.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Hoori Ajami): Improving runoff simulations in SMART modeling framework.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Jirka Simunek): Various novel applications of the models were implemented, and published 6 refereed articles in hydrological applications, 14 refereed articles in agricultural applications, 5 refereed papers on fate and transport of various substances, and 2 review manuscripts. Additional capabilities to rigorously consider soil processes to other models such as MODFLOW and DSSAT.</p><br /> <p>&nbsp;</p><br /> <p>University of California-Riverside (Laosheng Wu): Improve our fundamental understanding of vadose zone physical properties and processes, and how they interact with other environmental and biogeochemical processes across various spatial and temporal scales; Apply our knowledge of scale-appropriate methodologies to enhance the management of vadose zone resources that benefit agricultural systems, natural resources and environmental sustainability. Developed a model for pentachlorophenol dissipation; performed inverse modeling of hydrologic system; Evaluate salt tolerance and growth of Avocado rootstocks; Assessing salinity leaching efficiency in three Soils by the HYDRUS 1D and 2D Simulations.</p><br /> <p>.</p><br /> <p>University of Delaware (Yan Jin)</p><br /> <p>(1) We improved understanding on how rhizobacteria may cause soil structural change through EPS production and biofilm formation, which affects soil water retention.</p><br /> <p>(2) We tested the feasibility of imaging water retention and evaporation of control and bacteria-inoculated columns with x-ray tomography and neutron tomography simultaneously. Coupling the two powerful imaging equipment has the potential to give unprecedented resolution of all phases (solid, water, and air).</p><br /> <p>(3) We continue to expand our collection of data to demonstrate the importance of separating small colloidal fractions from conventionally defined dissolved phase.</p><br /> <p>(4) We demonstrated preferential pathways can be biological hotspots.</p><br /> <p>&nbsp;</p><br /> <p>Iowa State University (Robert Horton) and North Carolina State University (Joshua Heitman): Developed an empirical model to estimate soil thermal diffusivity; Developed a heat pulse sensor method to determine soil water content and soil bulk density si

Publications

<ol><br /> <li>Abolt, C.J., M.H. Young, A. Atchley, and D. Harp. 2018. Microtopographic control on the ground thermal regime in ice wedge polygons. The Cryosphere. 12:1957&ndash;1968. doi.org/10.5194/tc-12-1957-2018.</li><br /> <li>Abolt, C., T.G. Caldwell, B. Wolaver, and H. Pai (2018), Unmanned aerial vehicle-based monitoring of groundwater inputs to surface waters using an economical thermal infrared camera, Opt. Eng., 57(5), 053113, 9, 10.1117/1.OE.57.5.053113.</li><br /> <li>Adrian, Y. F., U. Schneidewind, S. A. Bradford, J. &Scaron;imůnek, T. M. Fernandez-Steeger, and R. Azzam, Transport and retention of surfactant- and polymer-stabilized engineered silver nanoparticles in silicate-dominated aquifer material, <em>Environmental Pollution</em>, <em>236</em>, 195-207, doi: 10.1016/j.envpol.2018.01.011, 2018.</li><br /> <li>Ajami, H., A. Sharma. 2018. Disaggregating Soil Moisture to Finer Spatial Resolutions - A Comparison of Alternatives, Water Resources Research, <a href="https://doi.org/10.1029/2018WR022575">https://doi.org/10.1029/2018WR022575</a></li><br /> <li>Akuoko, O., D. Kool, T.J. Sauer, and R. Horton. 2018. Surface energy balance partitioning in tilled bare soils. Agric. Environ. Lett. 3:180039. doi:10.2134/ael2018.07.0039</li><br /> <li>Arciniega-Esparza, S., J.A. Bre&ntilde;a-Naranjo, A. Hern&aacute;ndez-Espri&uacute;, A. Pedrozo-Acu&ntilde;a, B.R. Scanlon, J.-P. Nicot, M.H. Young, B.D. Wolaver. 2017. Baseflow recession analysis in a large shale play: climate variability and anthropogenic alterations mask effects of hydraulic fracturing. J. Hydro. 533:160-171. https://doi.org/10.1016/j.jhydrol.2017.07.059.</li><br /> <li>Arthur, E., M. Tuller, P. Moldrup, M.H. Greve, M. Knadel, and L.W. de Jonge, 2018. Applicability of the Guggenheim&ndash;Anderson&ndash;Boer water vapour sorption model for estimation of soil specific surface area. Eur. J. Soil Sci., 69(1):245-255, doi: 10.1111/ejss.12524.</li><br /> <li>Arthur, J. D., N. W. Mark, S. Taylor, J. &Scaron;imůnek, M. L. Brusseau, and K. M. Dontsova, Dissolution and transport of insensitive munitions formulations IMX-101 and IMX-104 in saturated soil columns, <em>Science of Total Environment</em>, <em>624</em>, 758-768, doi: 10.1016/j.scitotenv.2017.11.307, 2018.</li><br /> <li>Arya, L.M., and J.L. Heitman. 2018. Response to &ldquo;Comment on &lsquo;A Non-Empirical Method for Computing Pore Radii and Soil Water Characteristics from Particle Size Distribution&rsquo; by Arya and Heitman (2015)&rdquo;. Soil Sci. Soc. Am. J. 82:1595-1596.</li><br /> <li>Baatz, R, Sullivan, P.R., Li, L., Weintraub, S.R., Loescher H.W., Mirtl, M., Groffman, P.M., Young, M. H., and others, 2018, Steering operational synergies in terrestrial observation networks: opportunity for advancing Earth system dynamics modelling: Earth Surface Dynamics, 9:593-609, http://doi.org/10.5194/esd-9-593-2018.</li><br /> <li>Babaeian, E., M. Sadeghi, S.B. Jones, and M. Tuller, 2018. Mapping soil moisture with the OPtical TRApezoid Model (OPTRAM) based on long-term MODIS observations. Remote Sens Environ., 211:425-440, doi: 10.1016/j.rse.2018.04.029.</li><br /> <li>Bandala, E.R. and M. Berli. 2018. Nanomaterials: New agrotechnology tools to improve soil quality? In: F. L&oacute;pez-Valdez and F. Fern&aacute;ndez-Luque&ntilde;o, editors, Agricultural nanobiotechnology: Modern agriculture for a sustainable future. Springer Nature, Cham, Switzerland. p. 127-140.</li><br /> <li>Basinger, N.T., K.M. Jennings, D. Monks, W. Mitchem, J.L. Heitman, S. Chaudhari, J.L. Havlin, A.M. Howard, S.E. Spayd. 2018. Effect of Herbicide Strip Width and Postveraison Competition on Cabernet Franc, Growth, Berry Composition, and Yield. Catalyst. DOI:10.5344/catalyst.2018.17005.</li><br /> <li>Bayat, H., B. Mazaheri, and B.P. Mohanty, Estimating Soil Water Characteristic Curve using Landscape Features and Soil Thermal Properties, Soil and Tillage Research, 189, 1-14, 2019.</li><br /> <li>Beegum, S., J. &Scaron;imůnek, A. Szymkiewicz, K. P. Sudheer, and I. M. Nambi, Updating the coupling algorithm between HYDRUS and MODFLOW in the &lsquo;HYDRUS Package for MODFLOW&rsquo;, Technical Note, <em>Vadose Zone Journal</em>, <em>17</em>(1), 180034, 8 p., doi: 10.2136/vzj2018.02.0034, 2018.</li><br /> <li>Beegum, S., J. &Scaron;imůnek, A. Szymkiewicz, K. P. Sudheer, and I. M. Nambi, Implementation of solute transport in the vadose zone into the 'HYDRUS package for MODFLOW', <em>Groundwater</em>, 17 p., doi: 10.1111/gwat.12815, (accepted July 29 2018). 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Impact Statements

1. Michigan State University (Wei Zhang): Knowledge gained will improve knowledge on fate and risks of contaminants in soil, water and food crops, and contribute to better strategies for protecting ecosystem and human health.

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