Brief Summary of Minutes of Annual Meeting

• Ripendra Awal a Water Scientist/Civil Engineer with Prairie View University, TX, was elected 2018 Secretary for the W3128 group. Dr. Rhuanito Ferrarezi and Dr. Davie Kadyampakeni become 2018 Chair and Vice Chair respectively.

• Place for next meeting in 2018 was chosen to coincide with the Irrigation Association Show on the dates of Dec. 3-7, Long Beach, CA.

• Steve Loring mentioned that W3128 project expires on September 30, 2019. Thus, there is need for a new proposal submission before current project ends. Dr. Loring suggested the need for zoom meeting in winter 2018 (Jan 2018) and that a lead person (s) should be nominated for the proposal development. Dr. Loring further indicated that he would coordinate the efforts to call for the meeting. In the group discussion regarding the proposal development, the following objectives or areas of focus were mentioned to be considered for 2019 going forward:

1) Map ET across the US

2) Assessing water reuse and alternative sources of irrigation water/use of low quality water sources.

3) Assess barriers to adoption and managing of microirrigation using plant-based technologies (Ken Shackel will send out email, and solicit volunteers).

4) Fertigation/chemigation (Freddie Lamm led this discussion)

5) Irrigation management

6) Irrigation management: technology transfer to farmers and fertigation

Current objectives of the W3128 project include:

1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.
2. Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.
3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.

Discussion on whether a virtual or face-to-face meeting is important to ensure we finalize the proposal by Winter or Spring 2018.

• Bradley Rein provided NIFA perspective and overview regarding the Water for Food Production Systems (WfPS) where $32 million will be awarded to successful multidisciplinary, multi-institutional proposals out of 88 applications. Dr. Rein call for individuals interested in reviewing grant proposals to send him an email, if they are not on an application. He also mentioned that there are RFA with Foundation proposals, and other programs such as: Applied research and extension, CARE program (short term, 3-year grants, up to $300,000-500,000).
• Water and Energy Conservation Award, nationally, was accepted by Dr. Steve Loring on Thursday Nov. 10, 2017 from Irrigation Association.
• State reports were presented from Kansas, Florida, California, Texas, Oregon, and Ohio. Members noted the low turnout for the meetings. Steve Loring would contact Directors of Experiment Stations and find out why some members do not participate in the annual meetings.
• Field Tours

The participants of the annual meeting visited 2 sites on Monday, Nov. 6, 2017 at EPCOT site and at a reclaimed water irrigation facility Conserv II site in Orlando.

Florida

Florida

The Citrus App requires information on tree spacing (in row and between rows), soil water holding capacity, irrigation system output, and ET source. Water balance estimated using day of year and phenology-based Kc to estimate irrigation quantity and frequency requirements. Evaluation was conducted at three commercial citrus orchards in central and south Florida. The experiment was arranged in a randomized complete block design with four replications at each location. Three irrigation scheduling treatments for conventional irrigation were as follows: 1) Citrus App, 2) Grower determined irrigation, 3) Current University of Florida (UF/IFAS) recommended scheduling. Use of the citrus app consistently resulted in lower water use. Note, citrus trees in Florida have become affected by Citrus Greening disease since 2005 and all trees at the three locations in this study was determined to be infected by the pathogen. Water applications were significantly lower using the citrus app (3 out of 3 locations) and UF/IFAS recommendations (1 out of 3 locations) compared with grower schedules. Thus the citrus app used an average of 24% less water than the other two irrigation schedules. Citrus tree sap flow measurements were significantly greater and stem water potential lower for trees irrigated based on schedules produced by the citrus app and current UF/IFAS recommendations compared with trees irrigated using grower’s experience. As a result of lower water stress, yields were significantly greater for the citrus app (3 out of 3 locations) than the UF/IFAS recommendations and grower applications. Average increase in yield during the three years of the study was 18%. Yields in Florida citrus orchards have declined by 33% to 50% or more during the past 10 years making the results of this study more noteworthy.

Activities: Organized and specific functions or duties carried out by individuals or teams using scientific methods to reveal new knowledge and develop new understanding.

Presentations

1. Ferrarezi, R. S.; Geiger, T. C. 2017. Greenhouse cucumber production using sensor-based irrigation. 2017 Irrigation Show & Education Conference. Orlando/FL, United States.
2. Ferrarezi, R. S.; Geiger, T. C.; Weiss, S.; Greenidge J.; Dennery, S. 2017. Microirrigation equipment for okra cultivation in the U.S. Virgin Islands. 2017 Irrigation Show & Education Conference. Orlando/FL, United States.
3. Kadyampakeni, D. 2017. Update on Irrigation and Nutrient Management Studies of HLB Affected Trees.

Presented at the Citrus Institute on April 4, 2017 at South Florida State College, Avon Park, FL.

4. Kadyampakeni, D. 2017. Water Use and Irrigation Scheduling Effects on HLB Affected Citrus Trees Grown on          Sandy Soils. Irrigation Show & Education Conference on November 5-6, 2017; Orlando/FL, United          States.

Extension Bulletins

Zekri, M., A. Schumann, T. Vashisth, D. Kadyampakeni, K. Morgan, B. Boman, and T. Obreza. Fertigation for Citrus Trees. UF/IFAS Extension Publication HS1306, Gainesville, FL. http://edis.ifas.ufl.edu/hs1306

Kadyampakeni D.M., K.T. Morgan, M. Zekri, R.S. Ferrarezi, A.W. Schumann and T.A. Obreza. 2017. Irrigation Management of Citrus Trees. In: M.E. Rogers, M.M. Dewdney and T. Vashisth (Eds) 2017-2018 Florida Citrus Production Guide. p. 49-52. Available at: http://www.crec.ifas.ufl.edu/extension/pest/PDF/2017/Irrigation_Management.pdf

Kadyampakeni, D., K. Morgan, M. Zekri, R. Ferrarezi, A. Schumann, and T. Obreza. 2017. Citrus

Irrigation Management. UF/IFAS Extension Publication SL446, Gainesville, FL.

http://edis.ifas.ufl.edu/pdffiles/SS/SS66000.pdf

Kadyampakeni, D., K. Morgan, M. Zekri, R. Ferrarezi, A. Schumann, and T. Obreza. 2017. Irrigation

Management of HLB-Affected Trees. UF/IFAS Extension Publication SL445, Gainesville, FL.

http://edis.ifas.ufl.edu/ss659

Nebraska

In 2016, Dr. Irmak installed another SDI system in eastern Nebraska (5 acres) that has 136 plots/valves that are controlled individually. The system manifold is has three mainlines with triple-stack orientation. The research project that was conducted by Dr. Irmak on SDI frequency has been published in Irrigation Science. The objectives of this research were to: (i) to evaluate the effects of subsurface drip irrigation (SDI) amount and frequency on maize production and water use efficiency, (ii) develop production functions and quantify water use efficiency, and (iii) develop and analyze  crop yield response factors (Ky) for field maize (Zea mays L.). Five irrigation treatments were imposed: fully-irrigated treatment (FIT), 25% FIT, 50% FIT, 75% FIT, rainfed and an over-irrigation treatment (125% FIT). There was no significant (P > 0.05) difference between irrigation frequencies regarding the maximum grain yield; however, at lower deficit irrigation regime, medium irrigation frequency resulted in lower grain yield. There was a decrease in grain yield with the 125% FIT as compared to the FIT, which had statistically similar yield as 75% FIT. Irrigation rate significantly impacted grain yield in 2005, 2006 and 2007, while irrigation frequency was only significant during the 2005 and 2006 growing seasons (two dry years) and the interacting effect was only significant in the driest year of 2005 (P = 0.006). For the pooled data from 2005 to 2008, irrigation rate was significant (P = 0.001) and irrigation frequency was also significant (P = 0.015), but their interaction was not significant (P = 0.207). Overall, there were no significant differences between irrigation frequencies in terms of grain yield. Ky had interannual variation and average seasonal Ky values were 1.65, 0.91, 0.91 and 0.83 in 2005, 2006, 2007 and 2008, respectively, and the pooled data (2005-2008) Ky value was 1.14.

California

UC Davis

Accomplishments

The evapotranspiration (ET) of a 2-year-old almond tree was measured lysimetrically, and compared to the ET predicted from a recently published young peach tree model.  As found in the first year, measured ET values were substantially higher (about double) than predicted by the model, and in this second year, there was a marked overestimate of the soil components by the model.  A multi-year almond water production function experiment was continued, and thus far the yield effects of reduced irrigation have been minimal (reductions of from 5 - 25%, depending on location), despite imposing a relatively wide range of irrigation amounts (from 40-60").  A multi-year study was continued to document the long-term effects on tree and root health of winter flood irrigations in almond orchards for the purpose of groundwater recharge.  Thus far, no negative effects have been observed by applying an additional 24" of water during the dormant season (December/January).  The third year of an ongoing walnut irrigation test was performed and demonstrated that plant-based measurements (stem water potential, SWP) could be used to delay the first irrigation in the spring by about 1 month, with no detrimental effects on yield, and evidence was obtained that this practice may improve root health over the long term (years).

Extension presentations to growers and other industry personnel have been made at the annual almond and walnut conferences, in addition to presentations at grower meetings that have been organized by extension farm advisors.  The following industry supported projects will be continued: 1) Almond Water Production Function, 2) Almond Winter Water Management, 3) Almond Lysimeter (ET), 4) Walnut Early Season Water Management.

Presentations

Fulton A, Lampinen B, Shackel K. 2017. Walnuts: when to begin the irrigation season. West Cost Nut, March, 4-13.

UC Riverside

Outputs

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.

Activities: In 2017, we offered three-day short courses on how to use HYDRUS models at a) CSIRO Land & 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, we also 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.

Short-term Outcomes and Milestones

Objective 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.

Objective 2: Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.

We continue 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. The standard versions of HYDRUS, as well as its specialized modules, have been used by myself, my students, and my collaborators in multiple applications described below.

1. The Use of Hydrus Models to Evaluate Various Irrigation and Fertigation Problems - Agricultural Applications
2. Phogat et al (2017) used HYDRUS-2D to evaluate crop coefficients, water productivity, and water balance components for wine grapes irrigated at different deficit levels by a sub-surface drip. The impact of deficit irrigation on berry juice composition (Brix, pH and titratableacidity) was lower than the inter-seasonal variability
3. Li et al. (2017a) used experimental field data to assess the spatial distribution of soil water, soil temperature, and plant roots in a drip-irrigated intercropping field with plastic mulch.
4. Aggarwal et al. (2017) used HYDRUS-2D to simulate soil water balance and root water uptake in cotton grown under different soil conservation practices in the Indo-Gangetic Plain. The treatments included conventional tillage (CT), zero tillage (ZT), permanent narrow beds (PNB), permanent broad beds (PBB), ZT with residue (ZT + R), PNB with residue (PNB + R) and PBB with residue (PBB + R). The authors concluded that the Hydrus-2D model may be adopted for managing efficient water use, as it can simulate the temporal changes in SWC and actual transpiration rates of a crop/cropping system.
5. Li et al. (2017b) used HYDRUS-1D to simulate soil water regime and water balance in a transplanted rice field experiment with reduced irrigation.
6. Mallants et al. (2017a) used the UnsatChem module of HYDRUS-1D to asses water quality requirements of coal seam gas produced water for sustainable irrigation. Calculations showed that the use of untreated produced water resulted in a decrease in soil hydraulic conductivity due to clay swelling causing water stagnation, additional plant-water stress, and a reduction in plant transpiration. Results further illustrated that accounting for coupled geochemical, hydrological and plant water uptake processes resulted in more accurate water balance calculations compared to an approach where such interactions were not implemented. Coupling unsaturated flow modeling with major ion chemistry solute transport using HYDRUS provides quantitative evidence to determine suitable water quality requirements for sustainable irrigation using coal seam gas produced water.
7. Mallmann et al. (2017) used HYDRUS-1D to simulate zinc and copper movement in an Oxisol contaminated by long-term pig slurry (PS) amendments. Consideration of root growth and root water uptake processes in HYDRUS-1D simulations improved the description of measured field Zn concentrations. The feasibility of using PS amendments on agricultural Oxisols will be limited by Cu because the soil Cu threshold concentration is exceeded in approximately 30 yr. Moreover, the total loads of both trace metals allowed on agricultural soils are reached very fast when large rates are used, especially for Cu (19 yr), indicating that the long-term disposal of PS on agricultural soils should be done at low doses.
8. Karandish and Šimůnek (2017) used HYDRUS-2D to simulate nitrogen and water dynamics under various N-managed water saving irrigation strategies. Various scenarios were defined by combining 11 irrigation levels (0–100%), 8 N fertilization rates (0–400 kg ha−1) and two water-saving irrigation strategies: deficit irrigation (DI) and partial root-zone drying (PRD). The authors concluded that the HYDRUS-2D model, instead of labor- and time-consuming and expensive field investigations, could be reliably used for determining the optimal scenarios under both the DI and PRD strategies.
9. Hartmann et al. (in press) developed a root growth model and implemented it into HYDRUS. The model considers root growth to be a function of different environmental stresses. The effects of temperature in the root growth module was the first part of the newly developed HYDRUS add-on to be validated by comparing modeling results with measured rooting depths in an aeroponic experimental system with bell pepper.
10. Karandish et al. (in press) applied HYDRUS (2D/3D) for predicting the influence of subsurface drainage on soil water dynamics in a rainfed-canola cropping system. The simulation results demonstrated that the groundwater table management can be an effective strategy to sustain shallow aquifers in the subsurface-drained paddy fields during winter cropping.
11. Karimov et al. (in press) used HYDRUS-1D to evaluate whether a change in cropping pattern can produce water savings and social gains. The analysis was carried out for the Fergana Valley, Central Asia. Modeling results indicate that replacing alfalfa with winter wheat in the Fergana Valley released significant water resources, mainly by reducing productive crop transpiration when abandoning alfalfa in favor of alternative cropping systems. However, the winter wheat/fallow cropping system caused high evaporation losses from fallow land after harvesting of winter wheat. Double cropping (i.e., the cultivation of green gram as a short duration summer crop after winter wheat harvesting) reduced evaporation losses, enhanced crop output and hence food security, while generating water savings that make more water available for other productive uses.

1. Hydrological Applications
2. Lamorski et al. (2017) used the machine learning method to estimate the main wetting branch of soil water retention curve based on its main drying branch.
3. Slimene et al. (2017) used HYDRUS-2D to evaluate the role of heterogeneous lithology in a glaciofluvial deposit on unsaturated preferential flow.
4. Brunetti et al. (2017) used a surrogate model, i.e., the kriging technique, to approximate the deterministic response of HYDRUS-2D, and to simulate the variably-saturated hydraulic behavior of a contained stormwater filter. Surrogate modeling focuses on developing and using a computationally inexpensive surrogate of the original model. The main aim is to approximate the response of an original simulation model, which is typically computationally intensive.
5. Mallants et al. (2017a) used various modules (e.g., UnsatChem, HP1) of the HYDRUS-1D to demonstrate possible applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. A third application uses the HP1 module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in a soil leached with coal seam gas produced water following some accidental water release scenario. The examples were selected to show how users can tailor the required model complexity to specific needs, such as for rapid screening or risk assessments of various chemicals under generic soil conditions, or for more detailed site-specific analyses of actual subsurface pollution problems.
6. Liang et al. (2017) adapted the HYDRUS-1D model to simulate overland flow and reactive transport during sheet flow deviations. A hierarchical series of models available in HYDRUS-1D to account for both uniform and physical nonequilibrium flow and transport in the subsurface, e.g., dual-porosity and dual-permeability models, up to a dual-permeability model with immobile water, were adapted to simulate physical nonequilibrium overland flow and transport at the soil surface. The developed model improves our ability to describe nonequilibrium overland flow and transport processes and our understanding of factors that cause this behavior.
7. Phogat et al. (2017) used HYDRUS-2D to quantify the long-term stream-aquifer exchange in a variably saturated heterogeneous environment. The model was first calibrated and validated using piezometric heads measured near the stream and then used a) to quantify the long-term dynamics of exchange at stream-aquifer interface and the water balance in the domain and b) to evaluate the impact of anisotropy of geological materials, thickness, and the saturated hydraulic conductivity of the low permeability layer at the streambed, and water table fluctuations on the extent of exchange.
8. Li et al. (2017) used HYDRUS-2D to simulate the effects of lake wind waves on water and solute exchange across the lakeshore. The sensitivity analysis revealed that the hydraulic conductivity of the lakeshore zone and the characteristics of the waves were important factors influencing water and chloride exchange between the lake and groundwater systems. The simulated results helped us to better understand water and solute interactions in the lake–groundwater system during windy periods.
9. Diamantopoulos et al. (in press) used various FOCUS scenarios, which are used in Europe to assess the potential risk of groundwater to pesticides, in a model comparison study, in which they compared HYDRUS (2D/3D) with PEARL and PELMO. The authors concluded that HYDRUS (2D/3D) can be used as an alternative model for pesticide assessment studies since it provides a conceptual framework consistent with PEARL and PELMO but capable of two- and three-dimensional applications as well.
10. Brunetti et al. (in press) developed a computationally efficient pseudo-3D model for the numerical analysis of borehole heat exchangers. The numerical approach combines a one-dimensional description of the heat transport in the buried tubes of the exchanger with a two-dimensional description of the heat transfer and water flow in the surrounding subsurface soil, thus reducing the dimensionality of the problem and the computational cost. The proposed model was first validated against experimental data collected at two different experimental sites in Japan (with satisfactory results) and then combined with the Morris method used to carry out a sensitivity analysis of thermal properties. Finally, the model was used to investigate the influence of groundwater and lithologic heterogeneities on the thermal behavior of the GSHP.

III. Fate and Transport of Various Substances (Carbon Nanotubes, Viruses, Explosives)

With another member of the W3188 group, Scott Bradford we worked on three aspects of the transport of pathogens in the subsurface.

1. Zhang et al. (2017a) studied the role of cation valance and exchange on the retention and colloid-facilitated transport of functionalized multi-walled carbon nanotubes in a natural soil. The findings indicated that some (more than 20%) of the released MWCNTs by IS reduction and cation exchange were associated with the released clay fraction and suggested the potential for facilitated transport of MWCNTs by water-dispersible colloids.
2. Zhang et al. (2017b) used the C-Ride module of HYDRUS-1D to evaluate the experimental data that indicated that the presence of mobile MWCNTs facilitated remobilization of previously deposited CLD and its co-transport into deeper soil layers, while retained MWCNTs enhanced SDZ deposition in the topsoil layers due to the increased adsorption capacity of the soil. The modeling results demonstrated that the mobility of engineered nanoparticles (ENPs) in the environment and the high affinity and entrapment of contaminants to ENPs were the main reasons for ENP-facilitated contaminant transport.
3. Mark et al (2017) used HYDRUS-1D to evaluate results of the column studies involving the transport of the new, insensitive, energetic compound, NTO (3-nitro-1,2,4-triazol-5-one). The miscible displacement experiments were conducted under steady state and interrupted flow conditions using eight soils having varying physical and geochemical properties. Monod-type kinetics was implemented in HYDRUS-1D to simulate the observed increase in transformation rate with time. Results indicate very low adsorption of NTO in a range of soils, but natural attenuation through transformation that, depending on soil OC content and hydraulic residence time, could result in complete removal of NTO.
4. Arthur et al. (2017) used HYDRUS-1D to evaluate the miscible-displacement column experiments. The results confirmed the impact of sorption on retardation of DNAN (explosive) during transport. It was also shown that under flow conditions DNAN transforms readily with formation of amino transformation products, 2-ANAN and 4-ANAN. The magnitudes of retardation and transformation observed in this study result in significant attenuation potential for DNAN, which would be anticipated to contribute to a reduced risk for contamination of ground water from soil residues.
5. Sasidharan et al. (in press) evaluated transport and fate of viruses under managed aquifer recharge (MAR) conditions in a carbonate aquifer. While existing MAR guidelines only consider the removal of viruses via liquid phase inactivation, our results indicated that virus attachment to the solid phase was several orders of magnitude greater than liquid phase inactivation. Therefore, the authors concluded that current microbial risk assessment methods in the MAR guideline may be overly conservative in some instances.
6. Reviews
7. Jacques et al. (in press) reviewed recent adaptations of the HPx module of HYDRUS that have significantly increased the flexibility of the software for different environmental and engineering applications. They provide an overview of the most significant changes of HPx, such as coupling transport properties to geochemical state variables, gas diffusion, transport in two and three dimensions, and the support for OpenMP that allows for parallel computing using shared memory. The authors concluded that HPx offers a unique framework to couple spatial-temporal variations in water contents, temperatures, and water fluxes, with dissolved organic matter and CO2 transport, as well as bioturbation processes.
8. Šimůnek et al. (in press) reviewed new features of the version 3 of the HYDRUS (2D/3D) computer software package. These new features include a flexible reservoir boundary condition, expanded root growth features, and many new graphical capabilities of the GUI. Mathematical descriptions of the new features are provided, as well as two examples illustrating applications of the reservoir boundary condition.

Texas

Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.

Soil moisture sensor testing is being conducted in research field plots at Texas A&M AgriLife Research locations at Bushland, and Halfway, Texas.  Soil moisture monitoring also was conducted at three commercial farm locations near Muleshoe, Bushland and Dalhart, Texas.  On-site weather stations at all these locations (research and commercial farms) for integration of ET-based irrigation scheduling tools, soil moisture monitoring, and of course on-site precipitation and other weather parameters needed to conduct and interpret the studies.

At the Halfway site, soil water sensors include AquaSpy capacitance probes (soil moisture is monitored from 1 ft. to 5 ft. depths, in 4-inch intervals); and Acclima 315L TDR sensors at 0.5 ft., 1 ft., 2 ft., and 3 ft. depths; neutron probe soil moisture measurement is being used for comparison and continuity with ongoing research trials. These sensors are located in research plots under different treatments (conventional vs. no-till; and traditional full-season irrigation strategy vs. delayed seasonal irrigation strategy). All treatments are in cotton planted into terminated wheat (cover crop). 

Sensors at the Bushland site include Campbell Scientific Inc. CSI650 TDT and Acclima 315L TDR sensors. Placement of these sensors commenced as soon as the irrigation system was functional, and the first crop (winter wheat) was established. Additional sensors are being added to expand monitoring to the additional plots, accommodate more irrigation / cropping system treatments, and to conduct intensive comparisons of different sensors and installation configurations.

Decagon GS1 sensors were installed and connected through AgSense datalogger/ telemetry systems at three commercial farms near Muleshoe, Canyon/Bushland and Dalhart, Texas. Depending upon soil depths (horizons, layers, soil depth above caliche layer) at each site, 3 or 4 sensors were placed within the top 3-4 ft. of soil (placements were either 9”, 18” and 30” depths or 6”, 12”, 24” and 36” depths, depending on soil depth).  Multiple sites at each of these locations represent different crop rotations, soils, and cover crop treatments. Additional sites will be added in the coming crop season.  Soil moisture and weather data (from on-site weather stations) are available via a password protected Internet website to the cooperators, research team and interested USDA-NRCS staff, with permission from the cooperators.

Objective 2. Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.

In an effort to evaluate effects on cotton germination, a SDI system was installed on a 1-ha area with the field experiment beginning in 2013 and continuing for the fifth year in 2017. The factors considered are SDI lateral/row position and planting date. Included are five lateral/row position treatments:  T1 - 2-m spaced laterals irrigating 1-m crop rows equidistant from the lateral (traditional),  T2 - 2-m spaced laterals with two 0.75-m spaced rows equidistant from laterals and 1.25-m distances between row pairs (30-50 inch treatment),  T3 - 2-m spaced laterals with 2-m crop rows directly over lateral,  T4 - 2-m spaced laterals with one crop row directly over the lateral, and one crop row between laterals, and T5 - 1-m spaced laterals with 1-m rows directly over each lateral. The first planting date of each year is near 10 May with planting to occur in all lateral/row position treatments regardless of soil water condition. The second date is in the period from 14 to 35 days following the first planting with the planting date determined by the occurrence of favorable soil water conditions in the T1 treatment. Irrigation of all treatments is at approximately 70% ET, limited by an irrigation capacity of 5 mm d^-1.  Pre-plant irrigations of up to 125 mm are initiated 25 days prior to each approximate planting date and will continue for up to 10 days following planting or until seed germination has occurred in all treatments within a planting date.  2013 and 2016 results showed highest yield in early planted treatments of T1, T2, and T5.  2014 results showed relative small differences in yield due to planting date or row/lateral arrangement due to higher than average season rain. 2015 harvest results were non-conclusive due to a severe hail event on August 28.  Analysis of 2017 data is currently underway. This experiment will ultimately provide economic comparisons of water value (crop yield) relative to initial irrigation system cost and management.

A SDI experiment was initiated in 2014 and continued through 2017 that focused on efficiencies of pre- and early-season irrigations of cotton with deficit irrigation capacities. Treatments include pre-plant irrigations of 2 and 4 inches and early growing season irrigation capacities of 0.0, 0.1, and 0.2 in/day resulting in six treatments plus "pre-plant only" check.  Irrigation intervals are every seven days during cotton reproductive and maturation periods.  Tests were inconclusive due to late replanting in 2014 and heavy rains and hail during the pre-plant and early season irrigation periods in 2015. Cotton was replanted to grain sorghum due to hail and wind in 2016.  Analysis of 2017 data is currently underway. The results to date indicate no significant differences in yield due to irrigation treatments, therefore, water value was highest in treatments with no or limited pre-plant and early season irrigations. By applying recent field research findings and observing the frequency of challenging early season weather conditions, we hypothesize that irrigation productivity can be increased by up to 10% over typical limited irrigation capacity SDI strategies.

Objective 3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.

The DIEM Dashboard for Irrigation Efficiency Management irrigation scheduling and management tool is being evaluated in research and commercial farm operations.  DIEM integrates soil moisture (water balance), crop ET, and irrigation system efficiency and constraints to optimize irrigation management for cotton production systems. DIEM is unique in that it provides a prescription (pre-season, and updated throughout the season) to optimize limited irrigation.  DIEM is a web-based tool; beta test accounts can be requested free of charge from diem.tamu.edu.

Microirrigation research updates and management recommendations are presented in a variety of “face-to-face” venues, including traditional Extension “CEU” meetings for agricultural producers, irrigation professionals, agency staff, agribusiness and other interested audiences.  Examples of irrigation workshops and presentations are listed in the Educational Activities section below. Professional development events (in person and webinars) were conducted for County Extension faculty, with emphasis on the Texas High Plains, Rolling Plains and West Texas where there is most producer interest in microirrigation (especially subsurface drip irrigation).  Jim Bordovsky and Dana Porter presented several invited presentations for Groundwater Conservation Districts, irrigation conferences, university classes, and other groups/venues.  These and other technology transfer activities are included below. 

Educational Activities

Seminars, workshops similar education events

Porter, Dana. 2017. High Plains Irrigation Conference and Trade Show, Amarillo, TX, February 4, 2017. CEUs provided for Irrigation Association (IA) Certified Irrigation Designers (CID), Certified Agricultural Irrigation Specialists (CAIS) and American Society of Agronomy Certified Crop Advisers (CCA).

Porter, Dana. 2017. Monthly webinar and in-person soil and water management training series for Texas A&M AgriLife Extension Agents. December 2016 - August 2017.

Papers and presentations

Invited papers, presentations, and lectures

1. Bordovsky, J.P. 2017. Deficit irrigation research. High Plains Underground Water Conservation District Board of Directors meeting. Lubbock, TX. October 10, 2017.
2. Porter, D. 2016. Dashboard for Irrigation Efficiency Management: program overview and planned field testing and evaluation. High Plains Underground Water Conservation District Board of Directors meeting. Lubbock, TX. December 13, 2016.
3. Porter, D. 2017. Agricultural Irrigation. Invited Panelist on “Planning Ahead: Groundwater Projects for Tomorrow’s Needs”; 2017 Texas Groundwater Summit, Texas Alliance of Groundwater Districts, San Marcos, TX. August 29-31, 2017.
4. Porter, D. 2017. Irrigation Management and Crop Water Management. Guest Lecture in course, Crop Stress Management.  Texas A&M University Department of Soil and Crop Sciences. October 3, 2017.
5. Porter, D. 2017. Irrigation Water Quality and Salinity Management. Guest Lecture in course, Crop Stress            (recorded presentation). Texas A&M University Department of Soil and Crop Sciences.   October 5, 2017.

Conference or symposium proceedings: papers and posters presented

1. Andales, A., J. Bordovsky, and J. Agular. 2016. Irrigation scheduling tools in the Ogallala Region. USDA-ARS Ogallala Water CAP Report /Workshop. Denver, CO. Dec. 8, 2016.
2. Bordovsky, J.P. 2017. Texas High Plains cotton irrigation research. Oklahoma Irrigation Conference. Altus, OK. March 1, 2017.
3. Bordovsky, J.P. 2017. Dashboard for irrigation efficiency management (DIEM). 2017 Irrigation Association Technical Conference. Orlando, FL. Nov. 6-10, 2017.
4. Jordan, S., Bordovsky, J.P. and Porter, D.O. 2017. Comparison of multi-sensor capacitance and TDR soil moisture measurement methods in Texas South Plains irrigated cotton. Poster presentation. 2017 Beltwide Cotton Conferences. Dallas, TX. January 3-4, 2017.
5. Porter, D., J. Bordovsky, T.Marek, C. Hillyer. 2016. Soil sensor measurement research and extension activities in the Texas High Plains. USDA-ARS CIG Reporting/Workshop. Goodwell, OK. November 22, 2016.
6. Porter, Dana. 2016. Integrated projects and activities technology transfer / outreach of the Ogallala Water Coordinated Agriculture Project. (USDA-NIFA-CAP). Denver, CO. December 8-9, 2016.
7. Porter, Dana, Kevin Wagner, Jonathan Aguilar, Dan Rogers, Thomas Marek, Gary Marek, Saleh Taghvaeian, Freddie Lamm, Amy Kremen, Meagan Schipanski, and David Brauer. Education and Technology Transfer in Agricultural Water Management: Effective Communication with Stakeholders. Annual Conference, Universities Council of Water Resources.  Ft. Collins, CO. June 13-15, 2017.

Presentations at Extension meetings 

1. Bordovsky, J.P. 2017. Optimizing limited water. 2017 Lubbock / Hale County Precision Irrigation Workshop. Abernathy, TX. March 23, 2017.
2. Porter, Dana. 2017. South Plains irrigation update. Southern Mesa Ag Conference. Lamesa, TX. January 16, 2017.
3. Porter, Dana. 2017. New and Improved Irrigation Technology. Llano Estacado Cotton Conference. Muleshoe, TX. January 30, 2017.
4. Porter, Dana. 2017. South Plains irrigation update. South Plains Ag Conference. Brownfield, TX. January 17, 2017.
5. Porter, Dana. 2017. Precision irrigation tools. Hub of the Plains Ag Conference, Lubbock, TX. February 2, 2017.
6. Porter, Dana. 2017. Irrigation scheduling, monitoring and new developments. Lubbock / Hale County Precision Irrigation Workshop. Abernathy, TX. March 23, 2017. (20 attendees)
7. Porter, Dana. 2017. Dashboard for Irrigation Efficiency Management (DIEM) training for county agent beta testers. Lubbock, TX. February 23, 2017.
8. Porter, Dana. 2017. Understanding crop water use and management, soil moisture characteristics; soil-plant-atmosphere relationships; and planning for 2017 on-farm demonstrations. Texas A&M AgriLife Extension County Agent Professional Development Series. Lubbock, TX. March 23, 2017.
9. Porter, Dana. 2017. Wastewater Irrigation Management for Dairies. Dairy Outreach Program Area meeting, Dublin TX. April 6, 2017.
10. Porter, Dana. 2017. Irrigation and Precision Agriculture Technologies. Path to the Plate County Agent training and field demonstrations. College Station, TX. June 1, 2017.
11. Porter, Dana. 2017. Irrigation Management for Cotton Production. Cotton subject matter professional development training for county agents.  Texas A&M AgriLife Extension Service. Lubbock, TX. July 26, 2017.

Field days / crop tours

1. Bordovsky, J.P. 2017. Nuffield Visiting Scholars of New South Wales, Australia toured irrigation research facilities and ongoing projects at Texas A&M AgriLife Research. Halfway, TX. June 23, 2017.
2. Bordovsky, J.P. and Dana Porter. 2017. Irrigation practices and research activities in the Southern High Plains. Site tour and on-farm instruction. Texas 4-H Water Ambassadors. Halfway, TX. July 14, 2017. (Presentations were livestreamed on the Texas 4-H Water Ambassadors Facebook page.)
3. 3Bordovsky, J.P. 2017. Deficit irrigation research and strategies. Oral presentation. West Central Research and Extension Center Water and Crops Field Day. North Platte, NE. August 24, 2017.
4. Bordovsky, J.P. 2017. Deficit irrigation research. Oral presentation. 12th Annual Texas Alliance for Water Conservation Field Day. Edmonson, TX. September 6, 2017.
5. Porter, Dana. 2016. Irrigation and Water Management for High Plains Dairies. Southwest Dairy Day. Dalhart, TX. October 20, 2016.
6. Porter, Dana. 2017. Irrigation System Capabilities and Management. Texas A&M AgriLife Research Corn Breeders Tour. Lubbock and Halfway, TX. August 16-17, 2017.

Oregon

Broad expansion of microirrigation is needed. Unless timely action is taken, it is anticipated that water supply and water quality related crises will affect economies and resources of national and international importance. Microirrigation can reduce the waste of water to a negligible amount and reduce the transport of contaminants to surface water and groundwater. Irrigation events

can be fine-tuned to spoon feed water and nutrients just in time to minimize plant water stress. Microirrigation can optimize crop production (more crop per drop) and in many cases, increase the quality of agricultural products. Successful experimental microirrigation results will be scaled up to commercial size through this project. Microirrigation information will be transferred effectively to growers through many venues.

What was accomplished under the project goals?

Objective 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.

Vineyards -  In OR, WA, and CA soil-based measurements of soil water tension (SWT) managed drip irrigation scheduling is being combined with weather-based crop evapotranspiration managed drip irrigation scheduling for vineyard production.  We envision the optimization of yield and quality of vineyard production and financial return in cooperation with SmartVineyards. Ground truth of plant water potential is also being measured. Early during the growing season there are risks of wasting water and nutrients from over irrigation when the flush of early annual vine growth can be favored by minimal or very low levels of water stress. Later in the season, the relative amount of water stress that is most beneficial for the final product increases with the grape development stage. The ideal amount and timing (trajectories) of water stress (as measured by soil, plant, or weather data) are being studied for various cultivars, weather patterns, and sites. In Oregon we seek to measure the trajectories of stress. Modification of the stress trajectory holds the promise of better water use efficiency, protection of water quality, optimization of product quality, and the realization of providing a better return on vineyard investment. The approach is to collect and evaluate automated data that is interpreted and provided in real time to growers.

Automation of data collection and delivery. The automated approach to collect SWT data in vineyards (above) is being tested on onion, potato, quinoa, and stevia.

Seed production of native plants. In Oregon fixed irrigation schedules are being compared to soil- and weather-based scheduling for seed production from native plants. Plant species required 0 to 200 mm of supplemental irrigation per year to maximize seed yield. For a given species, yield responses to irrigation varied substantially by year. We have determined that accounting for rainfall during and prior to seed production improves the accuracy of estimating the amount of irrigation required.  Species differ in the preceding time interval where precipitation needs to be counted against the irrigation requirement.

Stevia  Although drip irrigation has been used to produce Stevia rebaudiana, few people have determined the best irrigation criteria in terms of soil water tension or crop evapotranspiration. Stevia leaf production was tested using irrigation onset criteria to trigger irrigation at different levels of SWT and triggering irrigation at 10 to 20 kPa optimized leaf yield. Equivalent levels of crop evapotranspiration were calculated and are being compared to reference evapotranspiration and the crop response to SWT.

Objective 2: Develop microirrigation designs and management practices that can be appropriately scaled to site- specific characteristics and end-user capabilities.

Protection of fresh produce from human pathogens in irrigation water Many fresh fruit and vegetables grown with drip irrigation are commonly consumed raw; therefore, they are subject to the FDA's provisions of the Food Safety Modernization Act. A major portion of the Produce Rule focuses on the microbiological quality of irrigation water used in the production of raw vegetable products. We conducted multi-year studies on the effect of contaminated irrigation water applied via furrow or drip irrigation on the relative fate of generic E. coli in water, in soil, and on onions during growth, curing, harvesting, and storage.

It is very important to have in irrigation practices to this food safety modernization act to use water effectively to produce fresh vegetables for fresh consumption. We have studied actual bacterial movement in the soil from water that exited drip tape. The water sources were highly contaminated with E. coli. Experiments have repeatedly shown that the bacteria in the water entering the soil did not move appreciably towards the onion bulbs. Furthermore the E. coli did not survive long in the soil or on the surface the bulbs.

Delivery of herbicides.  Herbicides were applied through the drip irrigation system in the hopes of achieving better control of yellow nutsedge. Outlook herbicide applied through drip irrigation was successful in helping to control yellow nutsedge.  This work is designed to expand the labeled use of drip-applied Outlook herbicide to control yellow nutsedge.

Delivery of fungicides. Fungicides were applied through the drip system to try to obtain better control of root fungi. Pink root and plate rot were not significant problems in the onion fields used for the trials and the products tested were not beneficial.

Adaptation of drip irrigation for potato production. Potato production is generally conducted with sprinkler irrigation. In the US drip irrigation has not been cost effective in comparison to sprinkler irrigation. We sought to change the drip irrigation configuration so that the drip irrigation system could be more efficiently utilized. Rows of potato plants were moved so that two rows of plants could be irrigated with a single drip tape. In this way only half the length of tape was needed to grow a potato crop. Currently sprinkler irrigation is used in part to cool the environment. To try to cool the environment of the developing potato tubers, we tested production with potatoes planted into flat beds. Double rows of plants with drip tapes 72 inches apart used less drip tape and water in 2017.

Objective 3: Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.

In objective 1 above, the automatic collection, evaluation, and deliver of soil and weather data is described. The goal is to interpret and deliver results, predictions, and projections in real time to growers' smart phones and laptops based on growers' demands. Growers are gaining real time access to information from their fields for water management decision making. These emerging tools and technology for growers have the potential to simultaneously optimize economic outcomes and minimize the losses of water and nutrients.

What opportunities for training and professional development has the project provided?

Undergraduate students were trained in research protocols and learned about crop irrigation and management.

How have the results been disseminated to communities of interest?

Results were communicated to growers by means of field days, workshops, grower meetings, written, and "on-line" reports. Results were disseminated at 3 different 2016 field days, through numerous written reports and presentations for growers and the public, scientific and international presentations, and by reports published on the internet.

What do you plan to do during the next reporting period to accomplish the goals?

Continue to 1) collect and deliver soil water tension data and interpretations to vineyard managers and growers of other crops to optimize drip-irrigation scheduling, 2) determine the irrigation criteria for seed production of perennial native plants where seed is needed for restoration activities and communicate the results to growers and others, 3) examine the possibility improving product effectiveness and reducing costs by injecting herbicides and fungicides through drip irrigation systems, and 4) actively disseminate results through field days, workshops, reports to growers and researchers, and web based reports on the internet.

International invited presentations

1. Shock, C.C. 2017. Creation and adoption of smart agriculture innovations to cope with climatic uncertainty. Keynote address at the International Conference on Biodiversity, Climate Change Assessment and Impacts on Livelihood, Hotel Crown Plaza – Soaltee, Kathmandu, Nepal, 10-12 January.

2.     Shock, C.C. 2017. Irrigation management for climate-smart agriculture. Keynote address at the International Conference on Technological Advances in Climate-Smart Agriculture and Sustainability (TACSAS 2017). Shri Guru Gobind Singhji Institute of Engineering and Technology, Nanded, India, 16-18 January.

3.     Shock, C.C. 2017. Climate-smart agriculture. Jain Irrigations Systems, Jalgaon, India, 24 January.

4.     Shock, C.C. 2017. Are field experiments easy? How to design, manage, and evaluate field experiments. China Agricultural University. Beijing, China. 6 June.

5.     Shock, C.C., E.B.G. Feibert, and N.L. Shaw. 2017 Ecological restoration hurdles to use rarely cultivated plants; Developing reliable seed production technology. Society for Ecological Restoration, Iguassu Falls, Parana, Brazil, 31 August.

National presentations

1. Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for seed production of Eriogonum species for use in Intermountain West rangeland restoration. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 21 September.
2. Feibert, E.B.G., C.C. Shock, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for Intermountain West rangeland legume seed production. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 19 September.
3. Shock, C.C. and F.X. Wang. 2017. Controlling irrigation onset by soil water tension. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 22 September.
4. Foley, K., C.C. Shock, and M. Santelmann. 2017. Drivers and barriers to producers’ voluntary adoption of practices that protect water quality. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 21 September.
5. Shock, C.C., E.B.G. Feibert, and N.L. Shaw. 2017. Oregon Report to W3128, Scaling microirrigation technologies to address global water challenges. Annual meeting of the W3128 working group, 5 November, Orlando, Florida.
6. Shock, C.C., F.X. Wang, A.D. Campbell, and H. Dominguez-Aguire. 2017. Triggering drip irrigation onset by soil water tension. International Irrigation Show, Orlando, Florida, 7 November.
7. Foley, K., C.C. Shock, and M. Santelmann. 2017. Drivers and barriers to producers’ voluntary adoption of practices that protect water quality. International Irrigation Show, Orlando, Florida, 8 November.

Regional presentations

1. Shock, C.C., S.R. Reitz, E. Feibert, A. Rivera, H. Kreeft, and J. Klauzer. 2017. Overview of research on the Food Safety Modernization Act. Idaho-Eastern Oregon Onion Growers’ Association Annual Meeting, Ontario, OR. 7 February.
2. Shock, C.C. 2017. Drip irrigation for onion: growers’ adoption of innovations. Clearwater Supply Annual Drip irrigation Meeting, 8 January, Ontario, Oregon.

Annual Reports

1. In Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
2. Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Onion internal quality in response to artificial heat and heat mitigation during bulb development. p 43-53. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
3. Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Timing of Internal quality problems in onion bulbs. p 54-62. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
4. Reitz, S. R., Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Kreeft, H., and Klauzer, J. 2017. Safe production of onion – 2016, understanding the fate of Escherichia coli in the soil. p 82-92. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
5. Reitz, S. R., Noble, J., Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Thrips and iris yellow spot virus management in the Treasure Valley. p 99-119. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
6. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Kilkenny, F., and Shaw, N. L. 2017. Direct surface seeding systems for the establishment of native plants in 2016. p 123-130. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
7. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of several native wildflower species planted in the fall of 2012. p 131-139. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
8. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Native beeplant seed production in response to irrigation in a semi-arid environment. p 140-144. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
9. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for native buckwheat seed production in a semi-arid environment. p 145-152. In: Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
10. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Johnson, D. A., Bushman, B. S., Shaw, N. L., and Kilkenny, F. 2017. Prairie clover and basalt milkvetch seed production in response to irrigation. p 153-159. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
11. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of five Lomatium species in a semi-arid environment. p 160-173 In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
12. Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of five native Penstemon species in a semi-arid environment. p 174-186. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.
13. Buhrig, W., Shock, C. C., Feibert, E. B. G., and Saunders, L. D. 2017. Wireless sensor network for ‘on farm’ soil moisture data acquisition and irrigation scheduling. p 231-237. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.

Field days

1. Native Wildflower Seed Production Field Day, (all trials with subsurface drip irrigation), Malheur Experiment Station, Oregon State University, Ontario, Oregon, 18 May 2017
2. “Planting native wildflower seeds”, Erik Feibert and Clint Shock
3. “Wildflower sequence of flowering”, Clint Shock and Erik Feibert
4. “Plants supporting pollinators”, Clint Shock and Erik Feibert
5. “Irrigation needs to produce seed of native wildflowers”, Clint Shock and Erik Feibert
6. “Seed harvests and expected seed yields”, Erik Feibert and Clint Shock
7. “Drip irrigation systems”, Erik Feibert and Clint Shock

2. Summer Farm Festival and Malheur Experiment Station Field Day, Malheur Experiment Station, Oregon State University, Ontario, Oregon, 12 July 2017.

Onion and potato drip irrigation tour. We show cased a study evaluating the response of multiple onion

cultivars to the recently registered method of applying Outlook (dimethenamid-p) through drip irrigation.  Evaluation of drip irrigation and comparison to sprinkler irrigation for potato to lower the comparative cost of drip irrigation. Latest work on internal rot in onion. Joel Felix, Clint Shock, and Erik Feibert.

3. Onion Variety Day, (all trials with drip irrigation), Malheur Experiment Station, Oregon State University, Ontario, Oregon, 22 August 2017.

4. Treasure Valley Irrigation Conference, Ontario, OR. 14 December 2017.

Oklahoma

Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.

Numerous research and extension activities have been conducted at Oklahoma State University during the reporting period to promote effective irrigation scheduling methods. A multi-state (OK, TX, KS) project on promoting sensor-based technologies to improve irrigation scheduling was successfully continued. As part of this project, canopy temperature and soil moisture sensors were installed at the Oklahoma Panhandle Research and Extension Center near Goodwell, OK, where corn and sorghum plots receive variable levels of irrigation application using a subsurface drip irrigation (SDI) system. The goal is to investigate how these two different types of irrigation scheduling approaches interact and how they can be utilized in managing SDI systems. In addition, soil moisture sensors (single sensors and probes) were installed at six other locations in cooperation with local growers. Sensors were evaluated for their accuracy, sensitivity to irrigation applications, and usefulness in improving irrigation scheduling. In choosing these sites a major criteria was to cover a wide range of crops, soil textures, and soil salinities.

Objective 3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.

Dissemination of information on adoption of microirrigation systems was accomplished by presenting at numerous field days, meetings, workshops, and in-service trainings.

Presentations:

1. Stivers J, Taghvaeian S. 2016. Field Comparison of Soil Moisture Sensors. 9^th International Conference on Irrigation and Drainage. Oct. 11-14, 2016; Fort Collins, CO.
2. Taghvaeian S. 2016. Irrigation Monitoring and Evaluation. Organic Oklahoma Fall Conference. Oct. 7, 2016; Oklahoma City, OK. (Contact hours: 11)
3. Taghvaeian S. 2016. Reuse of Wastewater using Drip Irrigation. OK Onsite Wastewater Conference. Nov. 10, 2016; Stillwater, OK. (Contact hours: 130)
4. Taghvaeian S. 2017. Sensor Technologies to Improve Irrigation Water Management. Central MN Irrigation & Nitrogen Management Clinic. Feb. 2, 2017; Ottertail, MN. (Contact hours: 65)
5. Taghvaeian, S. 2017. Irrigation Management Approaches. Irrigation Association Agriculture Faculty Academy. Jun. 8-Jun. 9, 2017; Grand Island, NE. Contact hours: 73
6. Taghvaeian, S. 2017. Grape Irrigation Management. OK Grape Management Course. Jul. 6, 2017; Perkins, OK. Contact hours: 15
7. Taghvaeian, S. 2017. Pecan Irrigation Management. OK Pecan Management Course. Jul. 11, 2017; Perkins, OK. Contact hours: 34
8. Taghvaeian, S. 2017. Monitoring Soil Water Content. Soil Workshop In-Service Training. Jul. 21, 2017; Perkins, OK. Contact hours: 10
9. Taghvaeian, S. 2017. Soil Moisture Sensor Technology. Fall Crops Tour. Sep. 1, 2017; Goodwell, OK. Contact hours: 50
10. Taghvaeian, S. 2017. Using Soil Moisture Sensors to Improve Cotton Irrigation. 2017 Carnegie Co-op Gin Fall Cotton Tour. Sep. 21, 2017; Hydro, OK. Contact hours: 23

Washington

What was accomplished under the project objectives?

Objective 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.

Three field research locations are being used to col

1. Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for seed production of two Eriogonum species in a semi-arid environment. HortScience. 52(9):1188–1194. doi: 10.21273/HORTSCI12186-17
2. Zhang, Y.I., F-X. Wang, C.C. Shock, K-J. Yang, S-Z. Kang, J-T. Qin, S-E. Li. 2017. Effects of plastic mulch on the radiative and thermal conditions and potato growth under drip irrigation in arid Northwest China. Soil and Tillage Research 172:1–11.
3. Zhang, Y-L., F-X. Wang, C.C. Shock, K-J. Yang, S-Z. Kang, J-T. Qin, and S-E. Li. 2017. Influence of different plastic film mulches and wetted soil percentages on potato grown under drip irrigation. Agricultural Water Management. 180:160–171.
4. Zhang, Y-L., F-X. Wang, C.C. Shock, K-J. Yang, Z. Huo, N. Song, and D. Ma. 2017. Potato
5. performance as influenced by the proportion of wetted soil volume and nitrogen under drip
6. irrigation with plastic mulch. Agricultural Water Management 179:260–270.
7. Parris, C.A., C.C. Shock, and M. Qian. 2017. Soil water tension irrigation criteria affects Stevia rebaudiana leaf yield and leaf steviol glycoside composition. HortSci. 52(1):154–161. doi: 10.21273/HORTSCI11352-16
8. Gonzalez-Fuentes JA, Shackel K, Lieth JH, Albornoz F, Benavides-Mendoza A, Evans YA. 2016. Diurnal root zone temperature variations affect strawberry water relations, growth, and fruit quality. Scientia Hort. 203:169-177.
9. Castellarin SD, Gambetta GA, Wada H, Krasnow MN, Cramer GR, Peterlunger E, Shackel KA, Matthews MA. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth. J. Ex. Bot. 67:709-722
10. Spinelli GM, Shackel KA, Gilbert ME. 2017. A model exploring whether the coupled effects of plant water supply and demand affect the interpretation of water potentials and irrigation management. Ag. Water Management 192:271-280.
11. Zuniga, C., L.R. Khot, S. Sankaran, and P.W. Jacoby. 2017. High resolution multispectral and thermal remote sensing based water stress assessment in grapevines to evaluate subsurface irrigation technique effects. Remote Sensing 9(9):961-976; doi:10.3390/rs9090961. [(ISSN 2072-4292) Impact Factor 3.244].
12. Kisekka, I., T. Oker, G. Nguyen, J. Aguilar and Danny Rogers. 2017. Revisiting Precision Mobile Drip Irrigation under Limited Water. Irrigation Science. 1-18. DOI: 10.1007/s00271-017-0555-7.
13. Lamm, F.R. and D. H. Rogers.   Longevity and performance of a subsurface drip irrigation system.  Trans ASABE 60(3):931-939
14. Lamm, F. R. and J. Puig-Bargués.   Simple equations to estimate flushline diameter for subsurface drip irrigation systems. Trans. ASABE 60(1):185-192.
15. Lamm, F. R.   Subsurface drip irrigation and possibilities in Alfalfa.  In: Proc., 2016 California Alfalfa and Forage Symposium, Reno, NV, Nov 29‐Dec 1, 2016. UC Cooperative Extension, Plant Sciences Department, University of California, Davis, CA 95616.  pp. 79-90.
16. Oker E. Tobias and I. Kisekka. 2017. Effect of Mobile Drip Irrigation on corn yield, biomass and water productivity. 2017. Paper #: 1701494. ASABE AIM Jul 16-19, 2017 Spokane, Washington USA.
17. Slack, D.C., R. Reyes Esteves, A. Espejel, B. Oyorsaval and Y. Ma. 2017. Subsurface Drip Irrigation: A Technology for Safer Irrigation of Vegetable Crops. Engineering and Applied Science Research 44(2):111-114
18. Chaibandit, K., S. Konyai and D.C. Slack. 2017. Evaluation of the Water Footprint of Sugarcane in Eastern Thailand. Engineering Journal 21(5): 193-201. DOI:10.4186/ej.2017.21.5.193.
19. Kadyampakeni, D.M. and K.T. Morgan. 2017. Irrigation scheduling and soil moisture dynamics influence water uptake by Huanglongbing affected trees. Scientia Horticulturae 224:272-279. http://dx.doi.org/10.1016/j.scienta.2017.06.037
20. Hamido, S.A., K.T. Morgan and D.M. Kadyampakeni. 2017. The effect of huanglongbing on young citrus tree water use. HortTechnology 27(5):659-665, doi: 10.21273/HORTTECH03830-17
21. Hamido, S.A., K.T. Morgan, R.C. Ebel amd D.M. Kadyampakeni. 2017. Improved irrigation management of sweet orange with Huanglongbing. HortScience 52(6):916-921. 2017. doi: 10.21273/HORTSCI12013-17
22. 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.
23. Sharma P., M.K. Shukla, P. Bosland and R. Steiner. 2017. Soil moisture sensor calibration, actual evapotranspiration and crop coefficients for deficit irrigated greenhouse chile. Ag Wat Manag. 179: 81-91.
24. 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, http://dx.doi.org/10.1080/15324982.2016.1275068.
25. Flores A., M.K. Shukla, D. Daniel, A. Ulery, B. Schutte, G. Pichionni and S. Fernald. 2016. Evapotranspiration Changes with Irrigation Using Saline Groundwater and RO Concentrate. J. Arid Environments. 131:35-45.