W1188: Characterizing Mass and Energy Transport at Different Scales

(Multistate Research Project)

Status: Inactive/Terminating

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SAES-422 Reports

Annual/Termination Reports:

[03/10/2005] [03/04/2006] [03/28/2007] [02/26/2008] [02/27/2009] [11/11/1111]

Date of Annual Report: 03/10/2005

Report Information

Annual Meeting Dates: 01/03/2005 - 01/05/2005
Period the Report Covers: 01/01/2004 - 12/01/2004

Participants

Ahuja,L. USDA-ARS CO; Blanco-Romero,A. USDA-ARS USSL; Bradford,S. USDA-ARS USSL; Butters,G. Colorado State Univ.;Draglia,M. Oregon State Univ.; Ewing,T. Iowa State Univ.; Gee,G. PNNL WA; Holcom,R. California State Fresno; Hopmand,J. CA Davis; Jin,Y. University of Delaware; Jones,S. Utah State Univ.; Kluitenberg,G. Kansas State Univ.; Leising,J. NV Water Authority; Miller,W. University of Nevada; Meadows,D. Desert Research Institute NV; Nielson,D. CA Davis; Ochsner,T. USDA-ARS MN; Or,D. University of Connecticut; Prunty,L. North Dakota State Univ.; Schaap,M. USDA-ARS USSL; Schwartz,R. USDA-ARS TX; Shouse,P. USDA-ARS USSL; Simunek,J. CA Riverside; Skagg,T. USDA-ARS USSL, Stoffregen,H. CA Riverside; Tuller,M. University of Idaho; van Genuchten,R. USDA-ARS USSL; Warrick,A. University of Arizona; Wierenga,P. University of Arizona; Wu,J. Washington State Univ.; Young,M. Desert Research Institute NV; Yates,S. USDA-ARS USSL; Zhang,F. PNNL WA; Caldwell,T. Desert Research Institute NV; Hong,S. New Mexico Tech; Iwama,K. Japan; Kelleners,T. USDA-ARS USSL; Pagliarin,C. Italy; Robinson,D. Utah State Univ.; Zhu,J. Desert Research Institute NV; Zhuang,J. University of Tennessee; Allen Mitchell University of Alaska (AA), Knighton,R. USAD-CSREES Washington DC.

Brief Summary of Minutes

Minutes:The annual meeting was held at the Circus Circus Hotel & Casino Las Vegas, NV January 3-5, 2005. Chairperson Yan Jin called the meeting to order and reviewed the previous year's annual report. Allen Mitchell (AA) gave the administrtive report including the renewal of the project through 09/30/2009. Ray Knighton gave the the CSREES representative's report. The W1188 business meeting followed where the 2004 annual report was approved unanimously. Scott Bradford USDA-ARS USSL was elected secretary for 2005. Next year's meeting was discussed and the membership voted to hold it at the Desert Research Institute (Accomodations at the Hard Rock Hotel and Casino). Technical presentation followed the morning coffee break. A total of 35 presentation were made on the three objectives of the 1999-2004 project outline. The presentations covered all aspects of the project including: geochemical modeling using the HYDRUS software, preferential flow and transport, water repellency, vadose zone flow and transport spatial and time scales, soil microbial biophysics, methodology of soil heat flux measurement, TDR calibration, relationship between soil anisotropy coefficient and saturation, infiltration into a layered soil with structured one-deminsional heterogeneity for binary or a tertiary system, improved hydraulic funtions of structured soils, soil hydromechanics, soil dialectric measurements, universal scaling law for soil water retention curves,and at low water contents, and other vadose zone models. The committee also presnted new instrumentation and methodologies for the study of soil flow and transport characteristics including a multifunctional heat probe for simultaneous measurement of water heat and solute transport, introduction of root zone water quality model, GPFARM and whole farm decision support system, IFARM DSS, and modification of tension infiltrometers to measure low flow rates.
A complete set of minutes is attached.

Minutes Attachment:

Attachment

Accomplishments

Objective 1: To study relationships between flow and transport properties or processes and the spatial and temporal scales at which these are observed: Researchers at the USDA-Salinity Lab (USDA-USSL) addressed processes governing colloid transport and retention in water saturated, physically heterogeneous systems. Colloid transport studies were conducted in water saturated physically heterogeneous systems to gain insight into the processes controlling transport in natural aquifer and vadose zone (variably saturated) systems. Modeling of the transport data indicated that straining was sometimes an important mechanism of colloid retention. Colloid retention in the heterogeneous systems was also influenced by spatial variations in the pore water velocity. The straining model typically provided a better description of the effluent and retention data than the attachment model, especially for larger colloids and finer-textured sands. Consistent with previously reported findings, straining occurred when the ratio of the colloid and median grain diameters was greater than 0.5%. In another project, USDA-USSL researchers worked on processes governing fate and transport of Cryptosporidium oocysts in saturated porous media. Accurate knowledge of the transport and deposition behavior for pathogenic Cryptosporidium parvum oocysts is needed to assess contamination and protect water resources. A physically realistic description of the data was obtained by modeling attachment, detachment, and straining. Dramatic differences in the predicted oocyst breakthrough curves were observed at greater transport distances for the various model formulations. At UC-Riverside, work was conducted on nitrogen best management practices (BMPs) for fertilizing turfgrass. Slow-release N and water soluble, fast-release N was applied at the same three rates. Several preliminary observations are: 1.Minimalist irrigation reduces the potential for nitrate leaching. However, sufficient irrigation is needed to promote healthy turfgrass. 2.An annual N rate of 4 to 6 lb/1000 ft2 produces an acceptable to good quality tall fescue lawn. Higher rates are not necessary and increase the risk of nitrate leaching. 3. Slow-release N sources (Nutralene, Milorganite, and Polyon) cause less nitrate leaching than a fast-release N source (ammonium nitrate). 4. The amount of nitrate leaching from a fast-release N source can be drastically reduced if N rates of individual applications do not exceed 1.5 lb/1000 ft2. UC-Riverside was also involved in a nursery runoff study. Because many nurseries are situated in urban environments, nursery runoff generally enters nearby streams and eventually enters large creeks or ocean estuaries. The overall purpose of this project is to prevent contamination of coastal waters from runoff from production nurseries. This will be achieved through the following objectives: (1) to minimize irrigation runoff from agricultural properties. This would allow growers to comply with the Basin Plan Objectives, Clean Water Act requirements, and future TMDL requirements from those currently in progress. (2) to reduce inputs to irrigation water, improve irrigation/fertilizer use efficiency, and reduce the potential of runoff that contributes to the non-point source pollution problems in the area; (3) to demonstrate effectiveness of BMPs and improved technologies in reducing runoff and leaching; and (4) To extend information gleaned from the project to growers in the Region as well as in the state. UC-Davis looked at the parameterization of large-scale hydrology models that may be hampered by the tremendous spatial heterogeneity of the subsurface, as well as the spatial and temporal variations in boundary conditions. An example of this approach is the Shuffled Complex Evolution Metropolis global optimization algorithm, SCEM-UA. It presents the multi-criteria calibration of a regional distributed subsurface water flow model for a 1,400 km2 irrigated agricultural area in the western San Joaquin Valley of California. Model parameters that were subjected to calibration included irrigation efficiency, effective drain depth and conductance, crop evapotranspiration correction coefficient, saturated hydraulic conductivity and specific yield values of coarse and fine fractions, and saturated hydraulic conductivity values defining water fluxes. There is a general lack of experiments that study the effects of soil structure and pore space characteristics on air and water permeability. Measurements showed large differences between disturbed and undisturbed samples, confirming the enormous impact of soil structure and pore space characteristics on flow. Regardless of soil disturbance, the researchers showed that the tortuosity/connectivity parameter, for the water permeability and air permeability were different. At Iowa State University, several studies were conducted. Through nondestructively monitoring coupled heat and water transfer in laboratory soil columns during a series of experiments, the researchers expect to gain insight into the coupled processes in unsaturated soils. Preliminary tests on Hanlon sand indicate that the new heat exchangers are able to establish and maintain desired temperature gradients with minimum heat loss from the soil columns. Scientists at Montana State University were active in a project where the focus was on microbial biophysics. Desaturation of soils results in fragmentation of aqueous soil microbial habitats, and increased tortuosity of liquid phase nutrient and metabolite mass transfer via diffusion. Montana State University and the University of Connecticut are collaborating on experimental and theoretical aspects of research to quantify the impacts of pore-scale physical conditions on soil microbial activities. Flat surfaces having matric potential-dependent-thickness water films were contrasted to grooves that remained water-filled at both matric potentials, thus creating a contrast in diffusion potential. Extensive areas (multiple locations and depth slices) of flat sections and grooves were included, for replicate coupons. Both Yellowstone National Park (Ragged Hills) soil and positive control Pseudomonas aeruginosa inocula produced relatively high cell densities for flat surfaces and grooves at -0.5 cm matric potential, while cell densities were much lower for flat surfaces than for grooves at -5 cm. This is consistent with expected similar diffusion potentials for both regions at the very wet -0.5 cm level, but lower diffusion potential in flat regions having only thin water films than for the still water-filled grooved regions at -5 cm matric potential. At North Dakota State University, field and laboratory studies were conducted related to the fate and transport of manure-borne hormones. The sorption, transformation, and mobility of two reproductive hormones, 17b-estradiol and testosterone have been studied in both field and laboratory settings. Both 17b-estradiol and testosterone are naturally present in animal manures and can be found in manures at concentrations that are potentially detrimental to aquatic organisms. Field experiments using lysimeters identified the fate of natural occurring 17b-estradiol and testosterone in manures. Subsurface water was analyzed for hormones beneath plots treated with hog lagoon material, raw manure, and compost materials. Hormones were detected at 0.6 m depth at concentration that may cause endocrine disruption. Hormones associated with the manure plots were at the lowest concentrations, while hormone concentrations found in the control plot were found to be highest. This result provided information that these compounds are antecedently present in the environment. Also, manures facilitate the degradation of hormones. The same research group at North Dakota State University worked on study on fate and transport of dioxins in soil-water systems. Dioxins are toxins that are produced from low-temperature combustion usually from anthropogenic sources, but can be produced from natural forest fires. They enter the ecosystem and little is know about the fate and transport of these potent chemicals in the soil. The three dioxin isomers that were used were nontoxic and behaved as true dioxins in the soil. These compounds were found to be strongly sorbed to soils and the strength of sorption was correlated to the organic matter content of the soil. If these chemicals can be transported to the lower depths of soil and if they are persistent; then the probability of subsurface water contamination increases. Experimental results can improve the understanding of contamination of surface and subsurface water and soil by these chemicals. Also, it can improve the remediation technologies used to clean contaminated areas. At the University of Minnesota, research emphasis was on analytic element modeling of two-dimensional, steady-state unsaturated flows. The analytic element method was applied to the solution of the steady-state Richards equation, transformed into the modified Helmholz equation using the Kirchhoff transformation and a space variable transformation. Results appeared to show that the analytic element solution is more accurate than the finite element solution. The finite element solution will also be used in 2005 to analyze the assumptions made in deriving the modified Helmholz equation. Colorado State University researchers conducted experimental studies that continue to investigate fundamental understanding of soil water hysteresis. Studies are focused on i) resolving an apparent relationship between wetting function parameters and degree of saturation, and ii) clarifying non-equilibrium effects in structured and non-structured soil. Utah State University participated within a project related to the effects of reduced gravity on porous media physical properties. Follow up imbibition experiments and novel water retention and saturated hydraulic conductivity experiments in different porous media were conducted. Experiments occurred during the 20 seconds of microgravity provided by the KC-135s parabolic flight. Experimental observations of measured water content and matric potential showed dynamic response to the parabolic flight. Reduced matric potentials compared to 1-g measurements were observed in a number of different porous media. Saturated hydraulic conductivity measurements were also carried out revealing no differences between Ks values at varying gravity levels except where density was reduced allowing significant quantities of free-floating particles. These data will provide valuable insight to advance the understanding of porous media soil physics in extra-terrestrial environments such as the International Space Station, the Moon or Mars. PNNL is developing better ways to assess the saturation dependent anisotropy of the hydraulic conductivity function. Soil anisotropy has been found to be a key in properly simulating flow and transport at the Hanford Site, where layered soils dominate the subsurface. The results show that the anisotropy coefficient, A, is independent of soil water retention properties. The model was tested using directional measurements of unsaturated hydraulic conductivity of undisturbed soil cores. Results show that the TCT model can describe different types of soil anisotropy, previously ignored in other models. Research at the University of Delaware has been centered on fate and transport of colloids (including viruses and other types of colloids) in porous media. Preliminary x-ray microtopography analysis suggests that viruses bypassed reaction sites in the matrix due to preferential flow heterogeneous medium (mixed glass beads), examination of the mechanisms responsible for deposition and transport of amphiphilic colloids with a wide range of particle sizes (20 420 nm) through variably saturated porous media. Results showed that decreasing water saturation enhanced colloid immobilization. This study highlights the importance of including size effect and surface properties in modeling or predicting deposition during transport of polydispersive colloids that often occur in natural environments, and investigation of the mechanisms of colloid retention on the air-water interface and air-water-solid interface at the pore scale. At Washington State University (WSU) the focus this year was on (1) studying colloid fate and transport in saturated and variably-saturated sediments, (2) synthesis and characterization of colloids formed under hyperalkaline conditions, (3) determining temporal dynamics of hydraulic conductivities in natural soils as affected by management practices. Using thermodynamic considerations the researchers showed that colloids likely attach to the solid-liquid-gas interface rather than the liquid-gas interface. In collaboration with the University of Delaware a study was initiated to compare the effects of a conservation tillage and chemical fallow on soil temperature and moisture regimes. Measured near-surface soil temperatures under conservation tillage were several degrees lower than under chemical fallow, but the chemical fallow plot stored the same or more water than the conservation tillage plot, reflecting the different characteristics of the two cropping systems. SHAW can be an effective modeling tool for evaluating the effects of cropping systems on soil temperature and water distributions. This information will help in the design of clean-up strategies for contamination at the Hanford site. At the University of Wyoming, studies focused on root length density (RLD). The RLD is an important parameter to model water and nutrient movement in the vadose zone and to study soil-root-shoot-atmosphere interactions. A generalized function was established to characterize the NRLD distributions versus normalized root depths. To verify the generalized function, the researchers measured RLD distributions of winter wheat (Triticum aestivum L.) using laboratory and field experiments for different soils, growing stages of wheat, atmospheric conditions, and water supplies. Using the generalized function, the researchers predicted winter wheat RLD and compared the predicted results with the experimental data and with results using other NRLD functions. A field experiment was conducted to measure distributions of soil water content, soil-plant osmotic potential, and root length density of winter wheat (Triticum aestivum L. cv. Nongda 186). The results showed that the inverse method was reliable and useful to estimate Lnrd distributions and simulate soil water flow with root-water-uptake continuously and effectively in field settings, without requiring any measured root density data. Objective 2: To develop and evaluate instrumentation and methods of analysis for characterization of flow and transport at different scales: USDA-USSL scientists were active in a number of areas including the search for a permanent storage facility for the geological disposal of high-level nuclear waste has motivated extensive research during the past several decades to characterize and predict fluid flow into and through unsaturated fractured rock. The researchers constructed several prototype instruments from porous stainless steel membrane, stainless steel casing, acrylic tubing, several pressure transducers, solenoid valves, and a data logger for automated control and data acquisition. An automated refill system was developed to facilitate long unattended equilibration periods typical for infiltration experiments on unsaturated fractured rock. Results show that the improved design reduces temperature effects on the infiltration rate, allows for much longer periods of unattended operation (auto-refill), and reduces evaporation from the infiltrometer. They also developed a method for the measurement of soil water content with capacitance probe sensors: Capacitance probe sensors are an attractive electromagnetic technique for estimating soil water content. At UC-Riverside, scientists worked on developing a potential hazard index for nitrate in states of the southwest in response degradation of aquifers under agricultural lands. A Nutrient Technical Advisory Committee (TAC), appointed by the California State Water Resources Control Board, recommended a hazard index approach to assess vulnerability of groundwater from agricultural nutrient contamination. Scientists are developing an interactive, web-based system where growers on irrigated lands in California, Arizona, or Nevada can assess their relative risk of contaminating groundwater. A database of over 500 soils and 150 crops in the three states has been compiled. The soils and crops were ranked for their leaching potential and rankings were reviewed by experts. An interactive website that calculates nitrate leaching potential and provides growers with best management practices was developed. Iowa State University scientists worked on field measurements related to surface soil chemical transport properties. The dripper-TDR method allows rapid field assessment of surface chemical transport properties. The researchers deployed a combination of drip-emitters and TDR to measure near-surface water content and chemical concentration, which in turn were used with CXTFIT for inverse prediction of soil chemical transport properties. Treatments included: No-till/no traffic, No-till/traffic, Chisel plow/no traffic, and Chisel plow/traffic. Several thermo-TDR probes were installed vertically from the soil surface, and heat-pulse and TDR measurements were recorded before a gravimetric sample was collected. Preliminary results indicate some success with the TDR portion of the measurement, but some difficulties with the heat-pulse measurements may impose some constraints. Montana State University researchers focused on three areas: (1) Impedance analysis approach for measuring dielectric spectra. The technique provides excellent agreement with the known dielectric constant of solvents, and evaluation in porous media is continuing, (2) Mutual interference by TDR signal multiplexers in electrical conductivity measurements, and (3) Temperature affects on TDR travel time measurements. TDR travel-time measurement for all soils and sand-clay mixtures are consistent with the earlier interpretations that these represent an interplay between the dielectric responses of free and bound water. The researchers consider that this phenomenon may now be confidently exploited, for example, to estimate specific surface area of soils and porous media. This will be highly useful in a number of soil management applications. In collaboration with Thomas J. Sauer (National Soil Tilth Laboratory) and Robert Horton (Iowa State University), University of Minnesota scientists have completed three field experiments to evaluate methods for measuring soil heat flux in surface energy balance studies. The researchers hope to demonstrate 1) the magnitude and frequency of errors in the plate method, 2) the likely causes of these errors, and 3) some alternatives to the plate method. The three needle gradient method the researchers utilized in this study is one promising alternative to the traditional plate method. The self-calibrating plate method which the researchers used at the soybean site also appears to give accurate readings. Both of these alternatives merit further research and development. Utah State University are continuing collaboration with University of Connecticut to improve water content determination using electromagnetic measurement techniques in saline and clayey soils. The major accomplishments for 2004 were the development of techniques to determine the permittivity of soil minerals, which greatly aids the modeling effort, a model was developed to describe the response of the Enviroscan in saline and clay soils. The Enviroscan is perhaps the most commonly used soil moisture sensor system currently used in agriculture, a number of articles have been accepted for publication, that begin to examine the application of sensor technology to spatial soil moisture content, and a methodology for characterizing electromagnetic sensors was developed. University of Connecticut and Utah State University in conjunction with Space Dynamics Laboratory, USU (Bingham) have developed a gas diffusion characterization measurement system for the International Space Station. University of Connecticut and Utah State University conducted experiments using Ground Penetrating Radar (GPR) with a suspended horn antenna to measure wheat and corn canopy properties and soil water content dynamics over bare and electrically terminating surfaces. University of Connecticut and Montana State University, are developing methods to estimate specific surface area of soils using the TDR thermo-dielectric response. To avoid measurement artifact in lossy soils, the researchers are quantifying the Maxwell-Wagner dielectric relaxation resulting from fragmentation polarization and DC electrical conductivity. University of Connecticut, Montana State University, and Utah State University researchers in collaboration with Volcani Center, Israel (S.P. Friedman) are evaluating the role of soil physical properties and water distribution characteristics on soil microbial behavior (activity, distribution and community composition). New methods to measure specific surface area, matric potential, and water retention will improve abilities to manage spatially variable soil and water resources efficiently and profitably. University of Idaho researchers investigated hydraulic and swelling properties of clays, visualization and quantification of spatial phase arrangement in bentonite-sand mixtures with x-ray computed tomography, developed observations of microstructure of clay-sand mixtures at different hydration states with scanning electron microscopy (with University of Connecticut), and developed a universal scaling law for soil water characteristic curves at low water contents (with University of Connecticut). Objective 3: To Apply scale-appropriate methodologies for the management of soil and water resources. Scientists at the USDA-USSL worked on two projects: 1. Application of soil fumigants with drip irrigation systems: Soil fumigants are used to control a wide variety of soil-borne pests in high-cash-value crops. Application of soil fumigants through drip irrigation systems is receiving increasing attention as a method to improve the uniformity of fumigant application. Little information is available on the emissions and soil distribution of fumigants following subsurface drip application, or the effect of plastic tarp on fumigant emissions in these systems. In these experiments, the fumigant compounds 1,3-dichloropropene (1,3-D), Vapam (a methyl isothiocyanate (MITC) precursor), and propargyl bromide (PrBr) were applied to soil beds via drip irrigation at 15 cm depth. Beds were tarped with either standard 1-mil high-density polyethylene (HDPE) or a virtually impermeable film (VIF). Cumulative emissions of 1,3-D, MITC, and PrBr in these tarped bedded systems was very low, amounting to <10% of the applied mass. Cumulative emissions of MITC and 1,3-D from a sandy loam field soil were decreased by ³80% by tarping the bed with VIF rather than HDPE. Monitoring the fumigant distribution in soil indicated that tarping the bed with VIF resulted in a more effective containment of fumigant vapors compared to use of a HDPE tarp. 2.Methyl bromide alternatives: Propargyl bromide (3-bromo-propyne, 3BP) is a potential replacement for the soil fumigant methyl bromide. A study was conducted to compare the volatilization and movement of 3BP in the soil profile for different irrigation treatments. Volatilization was about three times greater from non-irrigated soil. Irrigation and higher initial soil moisture content were more effective in controlling 3BP volatilization than the use of a HDPE tarp. At UC Riverside, research was also directed at ion diffusion in diffuse double layers. Ion diffusion and exchange in soil are usually treated as two independent processes. Ion diffusion is described by Ficks first and second laws without considering the influence of electrical field, while ion exchange is described by adsorption and desorption processes without considering the dynamic nature of ion distribution in the diffuse double layer (DDL). Researchers at UC-Davis analyzed water and sediment of irrigation and associated tail waters of a 30 ha corn field in the Central Valley in California, in order to quantify the sediment and carbon budget of a furrow-irrigated field. This field was monitored to assess the effects of minimum tillage versus standard tillage on soil C sequestration and greenhouse gas emissions. No differences were found between compositions of waters or sediments regarding tillage treatments. The measured soil C increase is approximately equal to 20% of the reported yearly carbon sequestration rates in long-term soil carbon sequestration experiments, that report C sequestration values of about100 kg C ha-1 y-1. To reduce the harmful effects of irrigated agriculture on the environment, the evaluation of alternative irrigation water management practices is essential. Micro-irrigation offers a large degree of control, enabling accurate application according to crop water requirements, thereby minimize leaching. Furthermore, fertigation allows the controlled placement of nutrients near the plant roots, reducing fertilizer losses through leaching into the groundwater. The presented two-dimensional modeling approach provides information to improve fertigation practices using four different micro-irrigation systems. The researchers found that seasonal leaching was the highest for coarse-textured soils, and conclude that fertigation at the beginning of the irrigation cycle tends to increase seasonal nitrate leaching. In contrast, fertigation events at the end of the irrigation cycle reduced the potential for nitrate leaching. At Montana State University, belowground mechanisms of invasive plant success were studied. The researchers hypothesized that C. maculosa (spotted knapweed), may succeed through a superior ability to access soil water. Researchers compared soil water uptake patterns under monocultures of the invasive C. maculosa resident perennial grasses, and a native perennial late-season forb, Rudbeckia hirta (blackeyed Susan), at two semiarid rangeland field locations. The Utah State University soil physics group is in the process of developing and testing a mobile sensor platform that can be integrated with agricultural machinery to provide mapping of soil water content, temperature, bulk electrical conductivity and other key properties of field soils. A prototype mobile sensor platform has been constructed based around an all terrain vehicle. Nevada is continuing research to better understand the linkages between soil morphology and soil hydrology. During 2004, Nevada focused on a new method to study the unsaturated hydraulic properties of individual soil peds (Meadows et al., 2004). Nevada has been seeking to apply concepts of time dependency on soil properties, to waste disposal practices. Waste disposal in Nevada, and other arid and semi-arid areas, often rely on evapotranspiration processes as a means of removing water that could otherwise percolate through soil and into the waste. The researchers hypothesize that these ET covers are also landforms that will be subject to environmental change over time. The researchers found good evidence for increased perennial plant cover, both from live and dead shrubs, at progressively older analog sites to about 10,000 years in the area of study; after 10,000 years, it appears that the plant cover decreased. The results support the hypothesis that ET covers are dynamic landforms that will evolve with time, and that environmental processes that influence landscape development are intimately linked to each other. At Washington State University, researchers have studied the scale-dependence of saturated and near-saturated hydraulic conductivity measurements. A 30-cm long soil core was taken from the topsoil of an agricultural field and hydraulic conductivities were measured with a constant head setup (tension infiltrometer). The core was dissected in 5-cm increments and hydraulic conductivities were measured after each dissection. Continued efforts were devoted to examining the uncertainty associated with water flow and solute transport through the variably-saturated, heterogeneous field at the Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Engineering and Environmental Laboratory (INEEL). The uncertainty in water and solute movement was related to the uncertainty in (i) categorization of the subsurface media into basalt and interbedding sediments; (ii) the spatial location of the interbeds; and (iii) estimated parameters in the geostatistical model. The US Department of Energys TOUGH2 model was used as the core deterministic model and the model predictions of flow and solute transport in response to changes in the aforementioned three factors were analyzed.

Publications

Abbasi, F., J. Feyen, and M. Th. van Genuchten. 2004. Two-dimensional simulation of water flow and solute transport below furrows: Model calibration and validation. J. Hydrol. 290: 63-79. Abbaspour, K. C., C. A. Johnson, and M. Th. van Genuchten. 2004. Estimating uncertain flow and transport parameters using a sequential uncertainty fitting procedure. Vadose Zone J. 3: 1340-1352. Abdou, H. M. and Flury, M., 2004. Simulation of water flow and solute transport in free-drainage lysimeters and field soils with heterogeneous structures. Eur. J. Soil Sci., 55: 229-241. Abriola, L., M, S. A. Bradford, J. Lang, and C. L. Gaither. 2004. Volatilization of binary nonaqueous phase liquid mixtures in unsaturated porous media. Vadose Zone Journal, 3, 645-655. Albright, W. H., C. H. Benson, G. W. Gee, A. C. Roesler, T. Abichou, P. Apiwantrangoon, B.F. Lyles, and S. A. Rock. 2004. Field Water Balance of Landfill Final Covers. J. Environ. Qual. 33:2137-2332. Al-Jabri, S.A., J. Lee, A. Gaur, R. Horton and D.B. Jaynes. 2004. A dripper-TDR method for in situ determination of hydraulic conductivity and chemical transport properties of surface soils. Adv. Water Resour. (in press). Allaire, S.E., Yates, S.R. and Ernst, F.F. 2004. Effect of soil moisture and irrigation on propargyl bromide volatilization and movement in soil. Vadose Zone J. 3: 656-667. Al-Mulla, Y., Wu, J. Q., Stöckle, C. O., Huggins, D. R., Schillinger, W. F., and Flury, M. 2004. Predicting soil water and temperature for conservation tillage and chemical fallow practices in the Pacific Northwest Dryland region. Trans. ASAE. (in preparation) Bachmann, J., S. K. Woche, M.-O. Goebel, M. B. Kirkham, and R. Horton. 2003. Extended methodology for determining wetting properties of porous media. Water Resour. Res. 39:10.1029/2003WR002143. Bakker, M. and J.L. Nieber, 2004. Analytic element modeling of cylindrical drains and cylindrical inhomogeneities in steady two-dimensional unsaturated flow, Vadose Zone J., 3: 1038-1049. Bakker, M. and J.L. Nieber, 2004. Two-dimensional steady unsaturated flow through embedded elliptical layers, Water Resour. Res., 40: W12406, woi:10.1029/2004WR0032995 Berli, M. and D. Or, 2004. Deformation of pores in viscoplastic soil material. International Journal for Numerical and Analytical Methods in Geomechanics (in press) Berli, M., M. Accorsi, and D. Or, 2004. Size and shape evolution of pores in a viscoplastic matrix under compression. International Journal for Numerical and Analytical Methods in Geomechanics (in review) Bittelli, M., Flury, M. and Roth, K., 2004a. Use of dielectric spectroscopy to estimate ice content in frozen porous media. Water Resour. Res., 40: W04212, doi:10.1029/2003WR002343. Bittelli, M., Flury, M., Campbell, G. S. and Schulz, V., 2004b. Characterization of a spiral-shaped time domain reflectometry probe. Water Resour. Res., 40: W09205, doi:10.1029/2004WR003027. Børgesen, C.D., and M.G. Schaap. 2005. Point and Parameter Pedotransfer Functions for Water Retention Predictions for Danish Soils. Geoderma, In Press. Bradford, S. A. M. Bettahar. 2004. Straining, attachment, and detachment, of Cryptosporidium oocysts in saturated porous media. Journal of Environmental Quality, In Press. Bradford, S. A., M. Bettahar, J. Simunek, and M. Th. Van Genuchten. 2004. Straining and attachment of colloids in physically heterogeneous porous media. Vadose Zone Journal, 3, 384-394. Brevik, E. C., T. E. Fenton, and R. Horton. 2004. Effect of daily soil temperature fluctuations on soil electrical conductivity as measured with the Geonics® EM-38. Precision Agriculture 5: 143-150. Brevik, E. C., J. Lee, T. E. Fenton, and R. Horton. 2003. The influence of soil water content, calcite content, and temperature on bulk electrical conductivity. J. Iowa Acad. Sci. 110(3-4): 56-60. Buchan, G. D. and Flury, M., 2004. Pathogen transport by water. In: B. A. Stewart and T. A. Howell (Editors), Encyclopedia of Water Science. Marcel Dekker, New York, pp. 1-4, doi: 10.1081/E-EWS 120021169. Casey, F.X.M., G. L. Larsen, H. Hakk, and J. SÇimÚunek. 2004. Fate and Transport of Testosterone in Agriculturally Significant Soils. Environ. Sci. Technol. 38(3):790-798. Casey, F.X.M., J. Lee, J. SÇimÚunek. 2004. Sorption, Mobility, and Transformation of Estrogenic Hormones in Natural Soil. J. Envrion. Qual. (In Review). Casey, F.X.M., N.E. Derby, D.W. Franzen, and D.V.P. Ralston. 2004. Lessons learned from a four-year precision agriculture study. In Annual Meetings Abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Chang, J.S., M. Radosevich, Y. Jin and D.K. Cha. 2004. Enhancement of phenanthrene solubilization and biodegradation by trehalose lipid biosurfactants. Environmental Toxicology and Chemistry (in press) Chaudhary, A., T.S. Colvin; T. 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Young, J. Vrugt and W.W. Wallender, 2004. Multi-criteria optimization of a regional spatially-distributed subsurface water flow model. J. Hydrology. In Press. Serbin, G. and D. Or, 2004. Ground-penetrating radar for measurement of crop and soil water content dynamics. Remote Sens. Environ. (in press) Serbin, G. and D. Or, 2004. Ground-penetrating radar measurement of soil water content dynamics using a suspended horn antenna. IEEE TGARS (in press) Serbin, G. and D. Or, 2004. Suspended ground-penetrating radar measurement of soil water content dynamics and implications for radar remote sensing. Water Resour. Res. (in review) Shafer, D.S., M.H. Young, S. Zitzer, E.V. McDonald, T.G. Caldwell. 2004. Coupled environmental processes: Implications for landscape development in the northern Mojave Desert. DRI Publication No. 45203. Singleton, M. J., E. L. Sonnenthal, M. E. Conrad, D. J. DePaolo, and G. W. Gee. 2004. Multiphase reactive transport modeling of seasonal infiltration events and stable isotope fractionation in unsaturated zone pore water and vapor at the Hanford Site. Vadose Zone J. 3: 775-785. Skaggs, T.H., T.J. Trout, J. Simunek, and P.J. Shouse. 2004. Comparison of HYDRUS-2D Simulations of Drip Irrigation with Experimental Observations, J. Irrig. Drain. Eng. ASCE, 130:304-310. Souza, C.F., D. Or, and E. E. Matsura, 2004. A variable-volume TDR probe for measuring water content in large soil volumes. Soil Sci. Soc. Am. J. 68:25-3 Staggenborg, S. A., G. J. Kluitenberg, and L. R. Stone. 2005. Estimating spatial soil water content to improve spatial yield predictions. In Proc. 7th International Conference on Precision Agriculture, St. Paul, MN. July 25-28, 2004. ASA, CSSA, and SSSA, Madison, WI. (in press). Steenhuis, T. S., A. G. Hunt, J.-Y. Parlange, and R. P. Ewing. 2004. Assessment of the application of percolation theory to a water-repellent soil. Aus. J. Soil Res. (in press). Steinberg, S., G. Kluitenberg, S.B. Jones, N. Diadzic, L. Reddi, M. Xiao, M. Tuller, R. Newman, D. Or, and I.D.Alexander. 2004. Physical and Hydraulic Properties of Baked Ceramic Aggregates Used For Plant Growth Medium. J. Am. Soc. Hort. Sci.. (in press) Steppuhn, H., M. Th. van Genuchten and C. M. Grieve. 2004. An index for the tolerance of agricultural crops to root-zone salinity. In: Proc. 41th Annual Alberta Soil Science Workshop, Alberta, Canada, Feb. 1-19, 2004. Sukop M.C., and D. Or, 2004. Lattice Boltzmann method for homogeneous and heterogeneous cavitation. Phys. Rev. Letters (in review). Sukop M.C., and D. Or, 2004. Lattice Boltzmann method for modeling liquid-vapor interfacial configurations in porous media. Water Resour. Res. 40 (1), 1509,10.1029/2003WR002333. Talbot, C.A., F.L., Ogden, and D. Or. 2004. Comment on Layer averaged Richards equation with lateral flow by Praveen Kumar (Adv. Water Resour. 27(5):521-31, 2004). Adv. Water Resour. (in press). Tuli, A.M., and J.W. Hopmans. 2004. Effect of degree of saturation on transport coefficients in disturbed soils. European Journal of Soil Science. 55:147-164. van Genuchten, M. Th., and J. Simunek. 2004. Integrated modeling of vadose-zone flow and transport processes. In: R.A. Feddes, G. H. de Rooij and J. C. van Dam (eds.), Unsaturated-Zone Modeling; Progress, Challenges and Applications, Wageningen UR Frontis Series, Vol. 6, Chapter 2, pp. 37- 69, x-xi, Kluwer Academic Publishers, Dordrecht, The Netherlands. van Genuchten, M. Th., and M.G. Schaap. 2004. Improved description of the hydraulic properties of unsaturated structured media near saturation. In: B. Faybishenko and P. A. Witherspoon (eds.), Proc. 2nd Int. Symp. on Dynamics of Fluids in Fractured Rock, Feb. 10-12, 2004, pp. 255-259, LBNL-54275, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA. van Genuchten, M. Th., J. Simunek, M. G. Schaap and T. H. Skaggs. 2004. Unsaturated zone parameter estimation using the HYDRUS and Rosetta software packages. In: T. J. Nicholson, J. E. Babendreier, P. D. Meyer, S. Mohanty, B. B. Hicks, and G. H. Leavesley (eds.), Proc. Int. Workshop "Uncertainty, Sensitivity, and Parameter Estimation for Multimedia Environmental Modeling", August 19-21, 2003, Rockville, MD, NUREG/CP-0187, pp. 41-43, U.S Nuclear Regulatory Commission, Rockville, MD. Vaughan, P.J., P.J. Shouse, S. Goldberg, D.L. Suarez, and J.E. Ayars. 2004. Modeling boron transport within and agricultural field: Uniform flow versus mobile-immobile water model simulations. Soil Sci.169(6):401-412. Vrugt, J.A., G.H. Schoups, Jan W. Hopmans, C. Young, W.W. Wallender, T.H. Harter and W. Bouten. 2004. Inverse modeling of large-scale spatially-distributed vadose zone properties using global optimization. Water Resourc. Res. 40:W06503, doi:10.1029/2003WR002706. Wang, K., R. Zhang, and F. Wang. 2004. A continuum fractal model for unsaturated soil hydraulic conductivity. Advanced in Water Science 2:206-210 (in Chinese). Wang, K., R. Zhang, and F. Wang. 2004. A fractal model for soil water retention function. Journal of Water Conservancy 5:1-6 (in Chinese). Wang, K., and R. Zhang. 2004. Testing the Pore-Solid Fractal Model for the Soil Water Retention Function. Soil Science Society of America Journal (in press). Wang, Q., M. Shao, and R. Horton. 2004. A simple method for estimating water diffusivity of unsaturated soils. Soil Sci. Soc. Am. J. 68: 713-718. Weisbrod, N., M. R. Niemet, M. L. Rockhold, T. J. McGinnis, and J. S. Selker. 2004. Infiltration of saline solutions into variably saturated porous media. J. Contam. Hydrol. Wendling, L. A., Harsh, J. B., Palmer, C. D., Hamilton, M. A. and Flury, M., 2004. Cesium sorption to illite as affected by oxalate. Clays Clay Miner., 52: 375-381. White, M. D. and M. Oostrom. 2004. STOMP Subsurface Transport Over Multiple Phases, Version 3.1., Users Guide. PNNL-14478. Pacific Northwest National Laboratory, Richland, Washington. White, M.D., M. Oostrom, and R.J. Lenhard. 2004. A practical model for mobile, residual, and entrapped NAPL in porous media. Groundwater. 42:734-746/ Wildenschild, D., J.W. Hopmans, M.L. Rivers and A.J.R. Kent 2004. Quantitative analysis of flow processes in a sand using synchrotron x-ray microtomography. Vadose Zone Journal. In Press. Williamson, T.N., B.D. Newman, R.C., Graham, and P.J. Shouse. 2004. Regolith water in zero-order chaparral and perennial grass watersheds four decades after vegetation conversion. Vadose Zone J. 3: 1007Ó1016. Williamson, T.N., R.C., Graham, and P.J. Shouse. 2004. Effects of a chaparral to grass conversion on soil physical and hydrologic properties after four decades. Geoderma. (In press) Woche, S. K., M.-O. Goebel, M. B. Kirkham, R. Horton, R. R. van der Ploeg, and J. Bachmann. 2004. Contact angle of soils as affected by depth, texture, and land management. European J. Soil Sci. (in press). Wraith, J.M. 2004. Review of Soil Water Dynamics, First Edition, by A.W. Warrick. Vadose Zone J. 3:1490. Wraith, J.M., D.A. Robinson, S.B. Jones and D. Long. 2004. Spatially characterizing apparent electrical conductivity and water content of surface soils with time domain reflectometry. Comp. Electron. Agric.(In Press). Wraith, J.M., D.A. Robinson, S.B. Jones, and D.S. Long. 2004. Spatially characterizing bulk electrical conductivity and water content of surface soils using TDR. Comput. Electron. Agric. Special Issue: Applications of electrical conductivity measurements in precision agriculture. (invited, in press) Wu, J. Q., Yang, L., Rossi, R., Schafer, A. L., Hull, L.C., Fairley, J. P., 2004. Uncertainty analysis of flow and transport through heterogeneous, variably-saturated field at INTEC, INEEL. Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract H11B-0298. Wu, L. Surface and Ground Water Quality. In (Fugerson ed.) Citrus Production Manual. UCDANR. Oakland, CA. (In press, 16 manuscript pages) Xue, X., R. Zhang, S. Gui. 2004. An improved disc infiltrometer method for calculating soil hydraulic properties. Canadian Journal of Soil Science, 84:265-273. Yang, L., Wu, J. Q., Rossi, R., Schafer, A. L., Hull, L.C., Fairley, J. P., 2004. Uncertainty analysis of flow and transport through heterogeneous, variably-saturated field at INTEC, INEEL. J. Hydrol. (in preparation) Young, M.H. E.V. McDonald, T.C. Caldwell, S.G. Benner, D.G. Meadows. 2004. Hydraulic properties of a desert soil chronosequence in the Mojave Desert, USA. Vadose Zone J. 3:956-963. Young, M.H., W. Albright, W. Zachritz, D.S. Shafer, K.D. Pohlmann, M. Cablk, S. Zitzer, E.V. McDonald. 2004. Alternative Cover Design for Edwards Air Force Base, California: Data Collection, Monte Carlo Modeling, and Design Sensitivity Analysis. DRI Publication No. 41192. Yu, G.R., J. Zhuang, K. Nakayama, and Y. Jin. 2004. Root water uptake and soil water profile as affected by rooting depth and root clustering. Plant, Cell and Environment. (in review) Zhang, F., S. Kang, J. Zhang, R. Zhang, and F. Li. 2004. Nitrogen fertilization on uptake of soil inorganic phosphorus fractions in the wheat root zone. Soil Science Society of America Journal 68:1890-1895. Zhang, N., G. Fan, K. H. Lee, G. J. Kluitenberg, and T. M. Loughin. 2004. Simultaneous measurement of soil water content and salinity using a frequency-response method. Soil Sci. Soc. Am. J. 68:1515-1525. Zhang, Z. F., A. L. Ward and G. W. Gee. 2004. A combined parameter scaling and inverse technique to upscale the hydraulic parameters for heterogeneous soils. Water Resour. Res. 40, W08306, doi:10.1029 /2003 WR002925, 2004 (13 pp). Zhang, Z. F., A. L. Ward and G. W. Gee. 2004. A parameter scaling concept for estimating field-scale hydraulic functions. J. Hydraulic Res. 42:93-103. Zhao, H., Deng, Y., Harsh, J. B., Flury, M. and Boyle, J. S., 2004. Alteration of kaolinite to cancrinite and sodalite by simulated Hanford Tank Wastes and its impact on cesium retention. Clays Clay Miner., 52: 1-13. Zheng, W., Papiernik, S.K., Guo, M. and Yates, S.R. 2004. Remediation of methyl iodide in aqueous solution and amended soils with thiourea. Environmental Science and Technology. 38:1188Ó1194. Zheng, W., Yates, S.R., Guo, M., Papiernik, S.K., and Kim, J.H. 2004. Transformation of chloropicrin and 1,3Ódichloropropene by metam sodium in a combined application of fumigants. Journal of Agricultural & Food Chemistry. 52(10):3002Ó3009. Zheng, W., Yates, S.R., Papiernik, S.K. and Guo, M. 2004. Effect of Combined Application of Methyl Isothiocyanate and Chloropicrin on Their Transformation. Journal Environmental Quality. 33: 2157-2164. Zhu, J., B. P. Mohanty, A. W. Warrick, and M. Th. van Genuchten. 2004. Correspondence and upscaling of hydraulic functions steady-state flow in heterogeneous soils. Vadose Zone J. 3: 527-533. Zhuang, J., Jin, Y. and Flury, M., 2004. Comparison of natural colloid and kaolinite transport in porous media. Vadose Zone J., 3: 395-402. Zhuang, J. J. Qi, and Y. Jin. 2004. Retention and transport of amphiphilic colloids under unsaturated flow conditions: Effect of particle size and surface property. Environ Sci. & Technol. (in review) Zhuang, J., Y. Jin, and M. Flury. 2004. Comparison of Hanford colloids and kaolinite transport in porous media. Vadose Zone J. 3: 395-402. Zuo, Q., J. Feng, R. Zhang and L. Meng. 2004. A generalized function of wheat's root length density distributions. Vadose Zone Journal 3: 271-277. Zuo, Q., L. Meng, and R. Zhang. 2004. Simulating soil water flow with root-water-uptake applying an inverse method. Soil Science 169: 13-24.

Impact Statements

W1188 scientists continue to significantly enhance the disciplines of soil physics and hydrology by creating new knowledge and methodologies for the next generation of scientists.
Disease outbreak from water-borne pathogens, viruses, and toxins is impacted by their fate and transport in soil systems. USDA-ARS scientists developed fundamental models of colloid and microbial transport in saturated soil systems that describe retention (straining) and deposition behavior that is necessary to assess contamination of surface and groundwater supplies and to protect the environment.
Disease outbreak from water-borne pathogens, viruses, and toxins is impacted by their fate and transport in soil systems. USDA-ARS scientists developed fundamental models of colloid and microbial transport in saturated soil systems that describe retention (straining) and deposition behavior that is necessary to assess contamination of surface and groundwater supplies and to protect the environment.
USDA-ARS scientists are studying multiple replacements for the ozone depleting fumigant methyl bromide in high-cash-value crops. They found significant reductions (as much as 80%) in volatilization of replacement compounds Vapam, PrBr, and 1,3,D by applying through drip irrigation and tarping with virtually impermeable film (VIF).
Utah collaborated with CT, KS, and ID scientists to study effects of reduced gravity on porous media properties utilizing NASAs KC-135 aircraft for parabolic flight. Data will provide valuable insight in understanding porous media soil physics in extraterrestrial environments on the International Space Station, moon, and Mars.
Washington State University and University of Delaware scientists collaborated in a study of conservation tillage and chemical fallow effects on soil temperature and moisture and developed a Simultaneous Heat and Water (SHAW) model which is an effective tool for evaluating the effects of cropping system on soil temperature and water distribution.
In the search for permanent storage for the geological disposal of high level nuclear waste, USDA-ARS scientists developed an improved tension infiltrometer for measuring fluid flow in fractured rock at very low flow rates and long infiltration times. This infiltrometer is capable of measuring fluid flux as low as 10 mm per year.
Degradation of aquifers under agricultural lands is a growing problem. UC-Riverside scientists developed an interactive website for assessing nitrate hazard index (HI) on farms in CA, NV, and AZ. This site calculates nitrate leaching potential and provides BMPs for growers and will reduce aquifer contamination.
Pacific Northwest National Laboratory scientists developed a sparse vegetation evapotranspiration model for the Subsurface Transport Over Multiple Phases (STOMP) simulator. It is being used to study the performance of surface barriers in containing subsurface migration of contaminants and protecting groundwater at the Hanford nuclear waste site. It is capable of assessing candidate barrier design and performance and has been judged a critical tool in protecting subsurface waters at the site.
W1188 scientists at UC Davis studied water and sediment of irrigation and associated tail waters of a 30-hectare cornfield to quantify the sediment and carbon budget. They monitored effects of minimum versus conventional tillage on soil C and greenhouse gas emissions. The measured soil C increase is approximately 20% of annual carbon sequestration rates reported in long-term carbon studies in the literature. The carbon in the organic matter of the sediment accounted for about two thirds of th

Date of Annual Report: 03/04/2006

Report Information

Annual Meeting Dates: 01/02/2006 - 01/04/2006
Period the Report Covers: 01/01/2005 - 12/01/2005

Participants

Warrick,A.,University of Arizona; Wierenga,P University of Arizona;
Rasmussen,W. University of Arizona; Ferre,P. University of
Arizona; Bradford, Scott, CA George E. Brown, Jr. Salinity Lab,USDA-ARS;
Ghodrati,M ,University of California; Hopmans, J., University of
California Davis, Jury,W. University of California; Leij,F. CA, George E. Brown, Jr. Salinity Lab, USDA-ARS; Nielsen, D. University of
California Davis; Rolston, D., University of California; Shouse, P, CA George E. Brown, Jr. Salinity Lab USDA-ARS, Simunek,J., University of California, Skaggs, T.,CA, George E. Brown, Jr. Salinity Lab USDA-ARS; van Genuchten,M., CA, George E. Brown, Jr. Salinity Lab USDA-ARS; Wang, Z., California State University, Wu, L. Dept. of Environmental Sciences, University of California; Ahuja,L., CO, USDA-ARS; Green, T., CO, USDA-ARS; Butters, G. Colorado State University; Or,D., University of Connecticut; Jin, D. Univ. of Delaware;
Sisson, J.,Idaho NEL; Hubbel, J., Idaho NEL.; Tuller, Markus, Univ. of Idaho; Ellsworth, T., University of Illinois; Cushman, J., Purdue University; Rao, P., Purdue University, Horton, R. Iowa State University, Ames, IA 50011
D. Jaynes, National Soil Tilth Lab, USDA-ARS, Kluitenberg, G., Kansas State University; Nieber,J., University of Minnesota; Ochsner,T., MN, USDA-ARS; Wraith, J., Montana State University; Tyler,S., University of Nevada, Reno;
M.H. Young, Desert Research Institute, University of Nevada, Hendrickx, J. New Mexico Tech; Casey,F., North Dakota State University, Fargo; Lee, J., University of Tennessee; Perfect,E. University of Tennessee; Evett, S.,TX, USDA-ARS-CPRL; Schwartz,R.,TX, USDA-ARS-CPRL; Jones, S., Utah State University, Flury, M., Washington State University, Wu, J., Washington State
University; Gee, W., WA, Battelle Pacific Northwest; Meyer,P.,OR, Battelle Pacific Northwest, Portland; Oostrom, M., WA, Battelle Pacific Northwest, Richland; Rockhold, M.,WA, Battelle Pacific Northwest Richland,
Ward, A., WA, Battelle Pacific Northwest, Richland, Zhang, Z. WA, Battelle Pacific Northwest, Richland; Zhang, R Dept. of Renewable Resources, University of Wyoming,
CSREES R. Knighton, USDA-CSREES, Washington, DC 20250-2200
Adm. Adv. G.A. Mitchell, Palmer Research Center, 533 E. Fireweed, Palmer, AK
99645

Brief Summary of Minutes

The annual meeting was held January 2-4, 2006 at the Desert Research Institute near Las Vegas, NV.The meeting was called to order by Mart Oostrom at 8:00 am on Monday January 2, 2006. CSREES representative Ray Knighton presented his agency report and announced current RFP's. The committee elected a new secretary Thomas Harter of UC Davis. The remainder of the sessions were devoted to rersearch presentations by the participants and a lengthy discussion of what models are appropriate for studies at the watershed scale. Details of the minutes as well as the complete annual report may be found on the W1188 website at http://www.soilsci.ndsu.nodak.edu/W188/W-188.html

Accomplishments

Objective 1: To develop an improved understanding of the fundamental soil physical properties and processes governing mass and energy transport and the biogeochemical interactions these mediate. Researchers from Washington State University (WSU) focused on (1) elucidating mechanisms of colloid fate and transport in unsaturated porous media, (2) colloid-facilitated contaminant transport, and (3) sorption of the radionuclide Cs on mineral surfaces. They completed studies on colloidal stability in vadose zone pore waters and colloid-facilitated Cs transport under unsaturated flow conditions. WSU researchers also conducted a study focusing on detailed field monitoring and WEPP modeling of runoff and erosion under two drastically different management practices at the PCFS near Pullman, WA, over the 20032004 winter season . Two main mechanisms causing runoff and erosion were observed in the field. First, runoff and erosion may result solely from soil thawing and snowmelt. Second, when rain fell on a snow-covered frozen ground, runoff would start as a consequence of the rain input and snowmelt. We determined relative mineral labilities under alkaline conditions representative for Hanford tank farm leaks. Cs sorption experiments on micaceous clays as affected by rhizosphere processes showed that bacterial exudates can enhance Cs desorption from minerals and alter Cs availability. WSU results have revealed important processes in colloid and colloid-facilitated contaminant transport, namely preferential colloid attachment to solid-water interfaces near the gas-solid-water interface and contaminant stripping from colloidal carriers. We have also demonstrated that over long time scales of months to years, colloidal suspensions in the vadose zone are likely not stable. At North Dakota State University, field and laboratory experiments included identification of fate, mobility, occurrence and persistence of bioactive chemicals. 17²-Estradiol and its primary metabolite estrone were evaluated to identify the dynamic processes of fate and transport as 17²-estradiol undergoes transformations in the soil. First, 17²-estradiol was continuously applied to a soil column and effluent was collected from the water moving through and out of the column. The metabolism of 17²-estradiol was identified as well as its simultaneous transformation. Second, a series of incubation studies were done to identify the degradation process of 17²-estradiol and whether it is an aerobic and/or aerobic process and whether microorganisms govern it. 17²-estradiol were only degraded under aerobic conditions and only by microorganisms. A series of soil sorption and column transport experiments were also done using non-toxic dioxins isomers of the most toxic dioxin, 2378-TCDD. TCDD dioxins were strongly bound to the soil, but their transport was possibly facilitated by colloidal transport. Lastly, a field plot study was done where manure was applied to three different plots where lysimeters were installed (60 cm below the surface) which were compared to a control. In all the lysimeter there were relatively high levels of 17²-estradiol detected in the leachate collected by the lysimeter and that there concentrations persisted throughout the collection period. These results did not agree with laboratory results, where it was expected there would be little or no mobility and very high metabolism rates. USU contribution to W1188 included an ongoing NASA-funded flight experiment focused on basic soil physics principles in reduced gravity. A flight experiment is scheduled to launch to the International Space Station in the summer of 2006. Second, part of an Inland Northwest Research Alliance (INRA)-funded Ph.D. fellowship project evaluated electromagnetic induction sensor performance. Third, ongoing work is underway for development of a field-scalewater content mapping system. NASAs Advanced Life Support (ALS) program anticipates plant growth as part of any long-term, bio-regenerative, life-support system in microgravity (e.g. ISS, Lunar or Mars mission). In order to insure reliable plant-growth, the porous-media rooting environment needs to be well controlled and monitored to support plant growth under the intense energy, mass, and volume constraints of space flight. Limited, costly and infrequent opportunities for long-duration experiments on orbit and the cost and limitations of short-term microgravity (¼g) opportunities on earth have limited progress toward quantifying unsaturated hydraulic properties of porous media under reduced gravity conditions. Scientists at the USDA-ARS National Soil Tilth Laboratory and Iowa State University developed methodology for predicting thermal conductivity at low water contents. They hypothesized that the addition of small amounts of water to a dry soil increases thermal conductivity by increasing the contact between mineral grains. University of Iowa and Minnesota scientists performed studies of coupled heat and water transfer in unsaturated soil for a series of conditions including 2 soils, 2 water contents, 3 mean temperatures, 3 constant imposed temperature gradients, and 3 oscillating temperature gradients. Thermo-TDR sensors (combined heat-pulse and TDR) were installed within closed soil cells for observing transient temperature and moisture conditions throughout the experiments. Boundary temperature gradients were applied using programmable water baths and heat exchangers. Temperature conditions approaching steady state were achieved within 4-5 days. The nondestructive techniques used in these experiments allow new insights into coupled heat and water movement with repeated and transient measurements of moisture and temperature for a given volume of soil under a variety of conditions. Preliminary work has been conducted to measure thermal and hydraulic properties of hydrophobic soil materials for the next series of experiments. Results indicate increasing water redistribution with increasing mean temperature and temperature gradient. Little thermally driven water redistribution was observed for sand at high water contents. The results will provide a comprehensive data set suitable for testing and developing coupled heat and water flow models. In the arid west, turfgrass is an intensively managed biota due to the high visual quality requirement. The high nitrogen (N) fertilizer inputs in golf-course turfgrass have raised some concerns regarding the potential for nitrate to leach into groundwater. A University of California Riverside study was conducted to investigate the amount of nitrate leaching on an overseeded bermudagrass fairway during the cool and warm season. consisting of 5 metal cylinders. Results showed that nitrate concentration and mass of the leachate in the the volume (R3-1) of leachate was collected from lysimeter assemblies each sand was lower than in the sandy loam. The difference was attributed to N immobilization through plant uptake and clipping removal since both clipping yield in the early stage and the root density after the completion of the 3-yr experiment in the sand were significantly higher than in the sandy loam. The leaching volume was greater in the sand than in the sandy loam that followed the same irrigation management practices due to the higher water holding capacity of the latter. It was further shown that the average nitrate concentration of the leachate was lower than that of the irrigation water in 5 out of the 6 seasons, implying that if the turfgrass is properly managed, it may provide an opportunity to mitigate nitrate loading to surface and ground waters, even when N application rate is high. In other work at Riverside, degradation of four commonly used pesticides diazinon, chlorpyrifos, chlorothalonil, and pendimethalin in waters from two nursery recycling ponds were investigated at an initial pesticide concentration of 50 ¼g/L. Results showed the persistence of diazinon and chlorpyrifos appeared to be prolonged in recycling pond waters as compared to surface stream waters, possibly due to decreased contribution from biotic transformation, while degradation of chlorothalonil and pendimethalin was enhanced. Activation energies of biotic degradation of all four pesticides were lower than abiotic degradation, indicating microbial transformation was less affected by temperature than chemical transformation. Overall, the pesticide degradation capacity of recycling ponds was better buffered against temperature changes than in surface stream waters. The University of Idaho contribution in 2005 were primary focused on development and improvement of understanding of the fundamental soil physical properties and processes governing mass and energy transport, and development and evaluation of instrumentation and methods of analysis for characterizing mass and energy transport in soils at different scales. We continued studies on hydraulic and swelling properties of clays. To gain better understanding regarding initiation and evolution of surface crack networks in active clay soils we performed well controlled dehydration experiments in conjunction with X-Ray Computed Tomography (CT) observations. A collaborative project with the University of Connecticut yielded an analytical model for prediction of seepage into subsurface tunnels and cavities. In addition we concluded a collaborative NASA project (USU, UConn, UI, KSU, USRA, and NCSER) on liquid behavior in porous media under reduced gravity conditions. Oregon State University activities focused on elucidating the mechanisms that govern the movement of liquid and solutes when cracks are present in a soil profile. In 2005 we completed the first stage toward the development of a numerical model to simulate water and solute redistribution within a soil profile with cracks. The model investigated the effect of the crack on (1) evaporative flux from the profile, (2) salt flux and salt accumulation towards the crack surface, and (3) the effect of crack presence on net downward flux of solute through the vadose zone. As part of this project we proposed a mechanism for enhanced evaporation consisting of thermally driven nighttime convective venting of the fractures. Convective venting leads to evaporative fluxes that can be far greater than those driven by diffusive venting. This project has brought to light a very important mechanism of evaporation that has not calculations of land-atmospheric water fluxes, or for the impact this has on salt redistribution and transport within the vadose zone. The project has further developed a strong infrastructure of expertise and tools, which provides a solid foundation for future theoretical, numerical, laboratory and field investigations. OBJECTIVE 2: To develop and evaluate instrumentation and methods of analysis for characterizing mass and energy transport in soils at different scales Washington State University tested fiberglass wicks for their suitability to sample colloids from vadose zone pore water. It has been possible so far to coat silica sand with aluminum and iron oxides and humic acid, but no method for clay coating was available. Our methodology allows the generation of a clay-based porous matrix, with hydraulic properties that can be varied by adjusting the grain size of the inert silica support. Impact: Our efforts on testing fiberglass wicks for colloid sampling provide the first systematic data on colloid sampling from vadose zone pore water. In situ colloid sampling in the subsurface is a challenging, but important, endeavor. Good and reliable tools are needed to assess colloid transport in situ. The technique developed to coat silica sand with aluminosilicate clays provides the tool to conduct dynamic flow experiments with clays, something that has not been possible before, because clays have such a low hydraulic permeability. Cal State Fresno University developed a transparent permeameter was designed and constructed for fast measurement of saturated hydraulic conductivity Ks. This device allows direct reading of water levels from the side of the tank, quick start/stop of batch measurements, and individual uses of the cells in a small tank or glass beak. Impact: This new design and construction of permeameter provide convenient and fast measurement of saturated hydraulic conductivity which is one of the most often needed parameters for characterizing water flow and contaminant transport in variably saturated soils and other porous media. North Dakota State developed a method for predicting field-scale transport was developed and evaluated An in situ method was used to estimate field soil preferential flow properties for a surface soil. These preferential flow soil properties were then used to calibrate a mechanistic-stochastic stream tube model to predict field-scale solute transport. To evaluate this prediction, a field-scale leaching study was done and solute redistribution was monitored over a period of nearly 40 days. This method reasonably predicted the field-scale transport over this time period. Utah State University conducted a study to determine the effect of variable temperature environments on instrumental drift as well as to compare the bulk soil electrical conductivity (ECa) depth relationship between the DUALEM 1-S and Geonics EM38-DD instruments. Soil mapping in water sheds using electromagnetic induction for electrical conductivity measurements was also explored as a means of characterizing soil properties. Measurements are related to soil texture and other properties of interest from distributed sampling. A vertical 2m deep by 1x1m instrumented plot was established with TDR probes and thermocouples for characterization of the vertical profile measurement character of the EMI instrument. The instrument comparison paper will provide users with valuable information regarding instrument and environmental factors affecting measurement quality. Ongoing work is utilizing EMI measurements for determination of texture and other soil properties. University of Arizona reports from last year were published. Included were the affect of variations in waterheads on infiltration in borders and basins and predominantly vertical flow through a spherical inclusion using the analytic element method. Also published were results for effective unsaturated hydraulic conductivity through a repeating, 1-D layered system. Objective 3: To develop and evaluate scale-appropriate methodologies for the management of soil and water resources. WSU conducted a study to investigate the effects of digital elevation models (DEMs) on deriving topographic and hydrologic attributes, and on predicting watershed erosion using WEPP v2005. A 3D-distributed watershed model was developed to simulate catchment-scale hydrological process like runoff, infiltration, plant water uptake, and discharge. The model directly interfaces with GIS data. We tested the model by comparing: (a) simulated and observed soil water contents for a laboratory experiment on one-dimensional infiltration in a soil slab, (b) simulated and observed soil water contents for a field experiment with one-dimensional flow, and (c) three-dimensional simulated and observed stream flow data for a 0.75-km2 hilly catchment in Central Italy. Cal State Fresno conducted a preliminary study to develop a Sequentially Activated Micro-Flood Irrigation System (SAMFIS). The practical purpose is to reduce agricultural runoff and deep percolation for ecosystem restoration in Central Valley and the Bay-Delta area of California. Irrigation efficiency can be significantly improved if control of water flow is engineered into the system and not left to human control, such as in the center pivot sprinkler systems. Flood irrigation mechanization has met with limited success, partly due to the complex physics involved in predicting the simultaneous surface sheet flow and unsteady infiltration in the soil, and balancing hydraulic parameters and the volume of runoff and deep percolation. We attempted to incorporate a computer program for surface irrigation simulation and design with innovative water delivery system that results in an automated surface irrigation system in which a low cost Sequential Irrigation Valve (SIV) will be used as the critical water-flow control device. The new concept of surface irrigation will result in a scientifically designed and technically programmed system that can be achieved without changing the existing field layouts and without arbitrary human intervention. University of California Riverside developed a new comprehensive simulation tool HP1 (HYDRUS1D-PHREEQC) that was obtained by coupling the HYDRUS-1D one-dimensional variably-saturated water flow and solute transport model with the PHREEQC geochemical code. The HP1 code incorporates modules simulating (1) transient water flow in variably-saturated media, (2) transport of multiple components, and (3) mixed equilibrium/kinetic geochemical reactions. The program numerically solves the Richards equation for variably-saturated water flow and advection-dispersion type equations for heat and solute transport. The program can simulate a broad range of low-temperature biogeochemical reactions in water, soil and ground water systems including interactions with minerals, gases, exchangers, and sorption surfaces, based on thermodynamic equilibrium, kinetics, or mixed equilibrium-kinetic reactions. We have released a new version 3.0 of HYDRUS-1D, a software package for simulating water, heat and solute movement in one-dimensional variably saturated media. The new features include a) flow equation that may consider dual-porosity-type flow with a fraction of water content being mobile, and fraction immobile, b) the transport equations that include provisions for kinetic attachment/detachment of solute to the solid phase and it can be thus used to simulate transport of viruses, colloids, or bacteria, c) modules for simulating carbon dioxide and major ion solute movement, d) new model of hysteresis, e) new analytical models for the soil hydraulic properties, and f) compensated root water uptake. North Dakota State University performed a statistical study to identify the interactions of nitrogen, weather, soil type, and irrigation on corn yield (Derby, 2005b). The significant interactions on yield were from nitrogen amounts and weather. Several zone delineation methods for precision management of nitrogen at the field scale were also compared (Franzen, 2005). Also, the six-year water quality history under irrigate corn production was reported (Derby, 2005a), where there was strong evidence for in-situ nitrate reduction as a result of denitrification. The statistical study on the interactions of various factors on corn yield can help to develop methods that conserve nutrient application. Potentially, in years that have poor growing weather, nutrient requirements can be adjusted so that maximum yields can be achieved while minimizing economic inputs. The zone management comparison study will lead to a more efficient use of nitrogen fertilizer and less environmental impacts from its use. Utah State University is continuing to develop and test TDR-based water content measurements in a mobile system that can be integrated with agricultural machinery to provide mapping of soil water content, temperature, bulk electrical conductivity and other key properties of field soils. The ability to obtain field scale water content distribution maps is an important goal for improving management of irrigated and rain-fed agriculture within watersheds as well as to rangeland and forestry. The goal is to develop field-scale water content and soil property mapping approaches using statistical models that lead to linkages between infield measurements and remotely sensed data for improved resource management. The automation and incorporation of this technology will facilitate improved monitoring and mapping of saline soils. Current research in Nevada is focusing on a multifaceted approach to investigating soil hydrology at a variety of scales, from the micron to the landscape. At the meso-scale, we have developed a modified evaporation experiment (Meadows et al., 2005c) to examine the hydraulic properties of individual soil peds. Significant variability (2 orders of magnitude) in hydraulic properties was shown to exist at the scale of tens of cm on older, well-developed desert pavements. Research from Nevada seeks to define effective hydraulic parameters for various large scale hydrologic processes in heterogeneous fields. The study of Zhu and Mohanty (2005a) investigated the effective hydraulic parameters for transient infiltration in terms of the optimal averaging schemes for the input fields of hydraulic and environmental parameters. The optimal effective p-norm derived for the random (input) parameters defines an optimal averaging scheme for the random input fields Nevada has also been examining whether an organic-based emulsion, used to stabilize environmental contaminants near the soil surface, may produce undesired impacts on local desert ecosystems The examination included potential hydrologic impacts as well as its impact on dust emission potential. The Encapco emulsion used in this study is a blend of organic esters, surfactants, water, and a proprietary chelating agent. The emulsion was tested on desert alluvial soils at the Yuma Proving Ground (YPG), Yuma, AZ, USA, and on controlled soil materials near Las Vegas, NV, USA. At YPG, triplicate tension infiltrometer measurements and rainfall simulation experiments were conducted to examine the temporal dynamics (~0 mo, 3 mo, 6 mo, 12 mo), dilution ratio (control, 4:1, 6:1), geomorphic effects (young vs. old soils), and surface disturbance (raked vs. natural) impact to the soils hydrologic properties. Results at YPG showed that the emulsion significantly reduced (~1 order of magnitude) the saturated hydraulic conductivity of the soil and decreased the time to ponding immediately following application. However, six months after treatment, few plots differed statistically from the pretreatment values, indicating a relatively short-lived hydrologic effect. Additional studies and details may be found in the complete annual report found on the W1188 website (see minutes).

Publications

Abdu, H., D.A. Robinson and S.B. Jones. 2005. A Complex Permittivity Model for a Coated Coaxial TDR Probe in Saline Solutions. Agronomy Abstracts, ASA, Madison, WI. Al-Jabri, S.A., J. Lee, A. Gaur, R. Horton, and D.B. Jaynes. 2006. A dripper-TDR method or in situ determination of hydraulic conductivity and chemical transport properties of surface soils. Adv. Water Resour. 29(2):239-249. Bahaminyakamwe, L., J. `imunek, J. Dane, J. F. Adams, and J. W. Odom, Copper mobility in soils as affected by sewage sludge and low molecular weight organic acids, Soil Sci., (in press). Beresnev, I. A., R. D. Vigil, W. Li, W. D. Pennington, R. M. Turpening, P. Iassonov, and R. P. Ewing. Elastic waves push organic fluids from reservoir rock. Geophys. Res. Lett. 32: L13303, 2005 Blonquist, J.M., S.B. Jones and D.A. Robinson. 2005. A Low Cost Time Domain Transmission Sensor with TDR Performance Characteristics for Determining Water Content in Soils. J. Hydrology 314:235-245. Blonquist, J.M., S.B. Jones, and D.A. Robinson. 2005. Standardizing Characterization of Electromagnetic Water Content Sensors: Part II. Evaluation of Seven Sensing Systems. Vadose Zone J. 4:1059-1069. Blonquist, J.M.Jr., S.B. Jones, and D.A. Robinson. 2005. Precise Irrigation Scheduling Using a Subsurface Electromagnetic Soil Moisture Sensor. Agronomy Abstracts, ASA, Madison, WI. 10 Boivin, A., J. `imunek, M. Schiavon and M. Th. van Genuchten, A comparison of pesticides transport processes in three contrasting field soils using Hydrus-2D, Vadose Zone Journal, (in press). Bradford, S. A., and M. Bettahar. 2005. Straining, attachment, and detachment, of Cryptosporidium oocysts in saturated porous media. Journal of Environmental Quality, 34, 469-478 (Log # 156114). Bradford, S. A., and M. Bettahar. 2006. Concentration dependent colloid transport in saturated porous media. Journal Contaminant Hydrology, 82:99-117. Bradford, S. A., J. `imunek, M. Bettahar, Yadata Tadassa, M. Th. van Genuchten, and S. R. Yates, Straining of Colloids at Textural Interfaces, Water Resources Research, 41, W10404, doi:10.1029/2004WR003675, 17 pp, 2005. Bradford, S. A., M. Th. van Genuchten, and J. Simunek. 2005. Modeling of colloid transport and deposition in porous media. Workshop on HYDRUS: Advanced modeling of water flow and solute transport in the vadose zone, University of Utrecht, Utrecht, The Netherlands, October 17-19, pp. 1-5. Bradford, S. A., Y. F. Tadassa, and Y. Pachepsky. 2006. Transport of Giardia and manure suspensions in saturated porous media. Journal of Environmental Quality, In Press. Caldwell, T.G., E.V. McDonald, and M.H. Young, 2005b. Soil water balance, seedbed microclimate, and the revegetation of arid lands in the Mojave Desert, In, The Mojave Desert: Ecosystem Processes and Sustainability, (Eds) R.H. Webb, L.F. Fenstermaker, J.S. Heaton, D.L. Hughson, E.V. McDonald, D.M. Miller, Submitted. Caldwell, T.G., E.V. McDonald, and M.H. Young. 2005c. Soil disturbance and hydrologic response at the National Training Center, Ft. Irwin, California, J. Arid Environs., revised. Caldwell, T.G., E.V. McDonald, and T. Bullard. 2005a. Linking Soils, Landscape and Geomorphology: Catalina Island, CA. Oak Researchers Workshop, Long Beach CA, March 22. Casey, F. X. M., J. `imunek, J. Lee, G. L. Larsen, and H. Hakk, Sorption, mobility, and transformation of estrogenic hormones in natural soil, J. of Environ. Quality, 34, 1372- 1379, 2005. Casey, F.X.M., J. Lee, and S. J. 2005. Sorption, Mobility, and Transformation of Estrogenic Hormones in Natural Soil. J. Envrion. Qual. 34:1372-1379. Chaplot, V.; A. Saleh, and D.B. Jaynes. 2005. Effect of the accuracy of spatial rainfall information on the modeling of water, sediment, and NO3-N loads at the watershed level. J.Hyrol. 312(1-4): 223-234. Chen, G. and Flury, M., 2005. Retention of mineral colloids in unsaturated porous media as related to their surface properties. Colloids Surf. Physicochem. Eng. Aspects, 256: 207- 216. Chen, G., Flury, M., Harsh, J. B. and Lichtner, P. C., 2005. Colloid-facilitated transport of cesium in variably-saturated Hanford sediments. Environ. Sci. Technol., 39: 3435-3442. Chen, L. and M.H. Young. 2005. Green-Ampt model for sloping surfaces. Water Resour. Res. Under revision. Coquet, Y., C. Coutadeur, C. Labat, P. Vachier, M. Th. van Genuchten, J. Roger-Estrade, and J. `imunek, Water and solute transport in a cultivated silt loam soil: 1. Field Observations, Vadose Zone Journal, 4, 573-586, 2005. Coquet, Y., J. `imunek, and J. Roger-Estrade, Modelling the effects of soil tillage on water and solute transport: the HYDRUS-2D/SISOL coupling, In: S. Torkzaban and S. M. 11 Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90-39341125, 78-81, 2005. Coquet, Y., J. `imunek, C. Coutadeur, M. Th. van Genuchten, V. Pot, and J. Roger-Estrade, Water and solute transport in a cultivated silt loam soil: 2. Numerical analyses, Vadose Zone Journal, 4, 587-601, 2005. Czigany, S., Flury, M. and Harsh, J. B., 2005a. Colloid stability in vadose zone Hanford sediments. Environ. Sci. Technol., 39: 1506-1512. Czigany, S., Flury, M., Harsh, J. B., Williams, B. C. and Shira, J. M., 2005b. Suitability of fiberglass wicks to sample colloids from vadose zone pore water. Vadose Zone J., 4: 175- 183. Das, B. S., J. M. Wraith, G. J. Kluitenberg, H. M. Langner, P. J. Shouse, and W. P. Inskeep. 2005. Evaluation of mass recovery impacts on transport parameters using least-squares optimization and moment analysis. Soil Sci. Soc. Am. J. 69:1209-1216. Decker, D. L., Ch. Papelis, S. W. Tyler, M. Logsdon, and J. `imunek, Arsenate and arsenite sorption on carbonate hosted precious metals ore, Vadose Zone Journal, (in press). Decker, D. L., J. `imunek, S. W. Tyler, Ch. Papelis, and M. Logsdon, Variably saturated reactive transport of arsenic in heap leach facilities, Vadose Zone Journal, (in press). Derby, N.E., and Casey, F.X.M. 2005a. Six-Year Water Quality History under Irrigated Corn Production. In Annual Meetings Abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Derby, N.E., Steele, D.D., Terpstra, J., Knighton, R.E. and Casey, F.X.M. 2005b. Nitrogen, Weather, Soil and Irrigation Effects and Interactions on Corn Yield. Agron. J. 97:1342- 1351. Du, B., A. Saleh, D.B. Jaynes, and J.G. Arnold. 2005. Evaluation of SWAT in simulating atrazine losses in stream discharge for Walnut Creek watershed (Iowa) [CD-ROM]. Watershed Management Conf. Proc. Atlanta, Georgia. Du, B., J.G. Arnold, A. Saleh, and D.B. Jaynes. 2005. Development and application of SWAT to landscapes with tiles and potholes. Trans. ASAE 48(3):1-13. Evett, S.R. 2005. International Soil Moisture Sensor Comparison. In Irrigation Insights No. 1, Second Edition, SOIL WATER MONITORING, P. Charlesworth (ed.). Land & Water Australia, Braddon, Australia. Pp. 68-71. (Chapter)Evett, S.R., Howell, T.A. and Tolk, J.A. 2005b. Time domain reflectometry calibration in terms of travel time, bulk electrical conductivity, and effective frequency. ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005) (Abstract) Evett, S.R. and Parkin, G.W. 2005. Advances in Soil Water Content Sensing: The Continuing Maturation of Technology and Theory. Vadose Zone J 2005 4: 986-991. Special Section: Soil Water Sensing. doi:10.2136/vzj2005.0099 Evett, S.R., Tolk, J.A. and Howell, T.A. 2005a. TDR laboratory calibration in travel time, bulk electrical conductivity, and effective frequency. Vadose Zone Journal 4:10201029 (2005). Special Section: Soil Water Sensing. doi:10.2136/vzj2005.0046 Evett, S.R., Tolk, J.A. and Howell, T.A. 2006. Sensors for Soil Profile Moisture Measurement: Accuracy, Axial Response, Calibration, Precision and Temperature Dependence. Submitted to the Vadose Zone Journal. Fan, Z., F.X.M. Casey, G.L. Larsen, and H. Hakk. 2005a. Fate and transport of 1278-TCDD, 1378-TCDD, and 1478-TCDD in soil-water systems. Chemosphere (In review). 12 Fan, Z., F.X.M. Casey, G.L. Larsen, and H. Hakk. 2005b. Persistence and fate of 17ß-estradiol and testosterone in agricultural soils. Environ. Sci. Technol. (In review). Fares, A., J. `imunek, L. R. Parsons, M. Th. van Genuchten, and K. T. Morgan, Effects of Canopy Shading and Irrigation on Soil Water Content and Temperature, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90- 39341125, 6-10, 2005. Franzen, D., Nanna, T., Gautam, R., Casey, F., Derby, N., Staricka, J., Panigrahi, S., Long, D., Sims, A. and Lamb, J. 2005. Evaluation and Effectiveness of Nitrogen Zone Delineation Methods. In Annual Meetings Abastracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. French, C., L. Wu, T. Meixner, D. Haver, J. Kabashima and W. A. Jury. 2005. Modeling nitrogen transport in the Newport Bay/San Diego Creek watershed of Southern California. Agricultural Water Management. (in press). Fuentes, J.-P. and Flury, M., 2005. Hydraulic conductivity of a silt loam soil as affected by sample length. Trans. ASAE, 48: 191-196. Furman, A. and A. W. Warrick. 2005. Unsaturated flow through spherical inclusions with contrasting sorptive numbers. Vadose Zone J., Vol. 4, 255-263. doi:10.21.36/vzj2004.0076. Gärdenäs, A., Hopmans, J. W., B. R. Hanson, and J. `imunek, Two-dimensional modeling of nitrate leaching for various fertigation scenarios under micro-irrigation, Agric. Water Management, 74, 219-242, 2005. Gaur, A., R. Horton, and D. B. Jaynes. 2006. Measured and predicted solute transport in a tile drained field. Soil Sci. Soc. Am. J. (in press). GEBRENEGUS, T., and M. TULLER, 2005. Quantitative Characterization of Surface Crack Networks in Sand-Bentonite Mixtures with X-Ray Computed Tomography. INRA Environmental & Subsurface Science Symposium, September 19-21, 2005, Big Sky, MT. GEBRENEGUS, T., and M. TULLER, 2005. X-Ray Computed Tomography for Qualitative and Quantitative Characterization of Surface Crack Networks in Clay Soils. SSSA Annual Meeting Abstracts, Nov. 6-10, Salt Lake City, UT. Gonçalves, M. C., J. `imunek, T. B. Ramos, J. C. Martins, M. J. Neves and F. P. Pires, Using HYDRUS to simulate water and solute transports in soil lysimeters, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90- 39341125, 38-41, 2005. Grant, S.A. and M.H. Young. 2005. Modification of general model of infiltration to include the effects of temperature and soil texture. Water Resour. Res. Submitted. Green. R., L. Wu, D. Berger. 2005. Development of BMPs for fertilizing lawns to optimize plant performance and nitrogenuptake while reducing the potential for nitrate leaching. CDFA Fertilizer Research & Education Program Conference Proceedings. Pp. 8-13. Greer, R.C., J.Q. Wu, P. Singh, and D.K. McCool, 2005. WEPP simulation of observed winter runoff and erosion in the Pacific Northwest, USA, Vadose Zone J., (in press). Hanson, B., J. W. Hopmans, J. `imunek, and A. Gärdenäs, Effect of fertigation strategy on nitrate availability and nitrate leaching under micro-irrigation, Conf. Proc. 2005 California Plant and Soil Conference, Science & Policy in California Agriculture, 13 California Chapter of the Amer. Soc. Of Agronomy, February 1-2, Modesto, CA, 107- 110, 2005. Haws, N. W., P. S. C. Rao, J. `imunek, and I. C Poyer, Single-porosity and dual-porosity modeling of water flow and solute transport in subsurface-drained fields using effective field-scale parameters, J. of Hydrology (in press). Heinse, R., S.B. Jones and D. Or. 2005. Inverse Modeling of Porous Media Unsaturated Hydraulic Properties in Microgravity. Agronomy Abstracts, ASA, Madison, WI. HEINSE, R., S.B. JONES, S.D. HUMPHRIES, R.W. MACE, S.L. STEINBERG, M. TULLER, R. NEWMAN, and D. OR, 2005. Measurement of Porous Media Water Retention during Parabolic Flight Induced Microgravity. Abstracts of the 33rd International Conference on Environmental Systems (ICES), 11-14 July, Rome, Italy. HEINSE, R., S.B. JONES, S.D. HUMPHRIES, R.W. MACE, S.L. STEINBERG, M. TULLER, R. NEWMAN, and D. OR, 2005. Measurement of Porous Media Water Retention during Parabolic Flight Induced Microgravity. Proceedings of the 33rd International Conference on Environmental Systems (ICES), July 2005, Rome, Italy. SAE Technical Paper 2005- 01-2950. Heinse, R., S.B. Jones, S.D. Humphries, R.W. Mace, S.L. Steinberg, M. Tuller, R. Newman, D. Or. 2005. Measurement of Porous Media Water Retention during Parabolic Flight Induced Microgravity. SAE Technical Paper no. 2005-01-2950. Helmke, M.F., W.W. Simpkins, and R. Horton. 2005. Simulating solute transport in fractured till: comparison of three common models. Ground Water 43: 877-889. Helmke, M.F., W.W. Simpkins, and R. Horton. 2005. Fracture-controlled transport of nitrate and atrazine in four Iowa till units. J. Environ. Qual. 34: 227-236. Hendrickx, J. M. H., G. Rodriguez, R. T. Hicks, and J. `imunek, Modeling Study of Produced Water Release Scenarios, Regulatory Analysis and Scientific Affairs Department, API Publication Number 4734, 146 pp., 2005. Heng, L.K. and S.R. Evett (Eds.). 2006. A Practical Guide to Soil Water Sensing. International Atomic Energy Agency. Vienna, Austria. (In Press). Chapters include:Field estimation of soil water content (Hignett, C. and Evett, S.R.); Gravimetric and volumetric direct measurement of soil water content (Evett, S.R.); Neutron moisture meters (Evett, S.R.); Conventional time domain reflectometry systems (Evett, S.R. and Heng, L.K.); Capacitance sensors for use in access tubes (Evett, S.R. and Cepuder, P.); Electrical resistance sensors for soil water tension estimates (Hignett, C. and Evett, S.R.). Horton, R. 2005. Soil physics. In: Lerner and Trigg (eds.) Encyclopedia of Physics. (in press). Horton, R. and A. Globus. 2005. Heat and moisture transport. In: D. Hillel et al. (eds) Encyclopedia of Soil and the Environment, p. 169-175, Elsevier Ltd. Jacques D., J. `imunek, D. Mallants, and M. Th. van Genuchten, Coupled reactive transport modelling based on the new biogeochemical code HP1, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90-39341125, 15-17, 2005. Jacques, D., and J. `imunek, User Manual of the Multicomponent Variably-Saturated Flow and Transport Model HP1, Description, Verification and Examples, Version 1.0, SCK"CENBLG- 998, Waste and Disposal, SCK"CEN, Mol, Belgium, 79 pp., 2005. 14 Javaux, M., Z. Wang, J. Feyen, D. Elrick, and M. Vanclooster. Correction to Prediction of fingering in porous media, Water Resour. Res., 41, W04005, doi:10.1029/2004WR003831, 2005. Jaynes, D.B., and D.L. Karlen. 2005. Sustaining soil resources while managing nutrients. In: Proc. Upper Mississippi River Sub-Basin Hypoxia Nutrient Committee Workshop, September 26-28, 2005, Ames, Iowa. Available: http://www.umrshnc.org/files/Hypwebversion.pdf. Jaynes, D.B., T.S. Colvin, and T.C. Kaspar. 2005. Identifying potential soybean management zones from multi-year yield data. Computers Electronics Agricult. 46:309-327 Jerez, J. and Flury, M., 2005. Humic acid, ferrihydrite, and aluminosilicate coated sands for column transport experiments. Colloids Surf. Physicochem. Eng. Aspects, (in press). Jerez, J., Flury, M., Shang, J. and Deng, Y., 2005. Coating of silica sand with aluminosilicate clays. J. Colloid Interface Sci., 294: 155-164. Johnson, D.W., J.F. Murphy, R.B. Susfalk, T.G. Caldwell, W.W. Miller, R.F. Walker, and R.F. Powers. 2005. The effects of wildfire, salvage logging, and post-fire N fixation on the nutrient budgets of a Sierran forest. Forest Ecology & Management 220:155-165. Jones, S.B., J.M. Blonquist, D.A. Robinson, V.P. Rasmussen, and D. Or. 2005. Standardizing characterization of electromagnetic water content sensors: Part I. methodology. Vadose Zone J. 4:1048-1058. Jones, S.B., M. Tuller and D. Or. 2005. Characterizing Liquid Imbibition in Porous Media under Microgravity. Agronomy Abstracts, ASA, Madison, WI. JONES, S.B., M. TULLER, and D. OR, 2005. Characterizing Liquid Imbibition in Porous Media under Microgravity. SSSA Annual Meeting Abstracts, Nov. 6-10, Salt Lake City, UT. Jones, S.B., R. Heinse, G.B. Bingham and D. Or. 2005. Modeling and Design of Optimal Growth Media from Plant-Based Gas and Liquid Fluxes. SAE Technical Paper no. 2005-01-2949. Kaleita, A.L., J.L. Heitman and S.D. Logsdon. 2005. Field calibration of the Theta Probe for Des Moines Lobe Soils. Appl. Eng. Agric. 21(5):865-870. Karlen, D.L., D.L. Dinnes, D.B. Jaynes, C.R. Hurburgh, C.A. Cambardella, T.S. Colvin, and G.R. Rippke. 2005. Corn response to late-spring nitrogen management in the Walnut Creek watershed. Agron. J. 97(4):1054-1061. Kelleners, T. J., R. W. O. Soppe, J. E. Ayars, T. H. Skaggs, and J. `imunek, Inverse analysis of upward water flow in a groundwater table lysimeter, Vadose Zone Journal, 4, 558572, 2005. Kelleners, T.J., D.A. Robinson, R.W.O Soppe, J.E. Ayars, and T.H. Skaggs, 2005. Frequency dependence of the complex permittivity and its impact on dielectric sensorcalibration in soils, Soil Sci. Soc. Am. J., 69:6776. Kelleners, T.J., R.W.O Soppe, J.E. Ayars, T.H. Skaggs, and J. Simunek. 2005. Inverse analysis of upward water flow in a groundwater table lysimeter, Vadose Zone J., 4:558572. Kluitenberg, G.J. 2002. Heat capacity and specific heat, p. 1201-1208, In J. H. Dane and G. C. Topp, eds. Methods of Soil Analysis. Part 4. Physical Methods. Soil Science Society of America, Madison, Wisconsin. Knight, J. H., and G. J. Kluitenberg. 2005. Analytical solutions for sensitivity of well tests to variations in storativity and transmissivity. Adv. Water Resour. 28:1057-1075. Kodeaová, R., J. Kozák, J. `imunek, and O. Vacek, Single and dual-permeability models of chlorotoluron transport in the soil profile, Plant, Soil and Environment, 51(7), 310-315, 2005. 15 Kodeaová, R., M. Kocárek, J. `imunek, and J. 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Köhne, and J. `imunek, Bromide transport at a tile-drained field site: experiment, one- and two-dimensional equilibrium and non-equilibrium numerical modeling, J. Hydrology, (in press). Köhne, S., J. `imunek, J. M. Köhne, and B. Lennartz, Simulating simultaneous nitrification and denitrification with a modified 2D-mobile immobile model, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90-39341125, 65-68, 2005. Kung, K.J.S., M. Hanke, C.S. Helling, E.J. Kladivko, T.J. Gish, T.S. Steenhuis, and D.B. Jaynes. 2005. Quantifying pore-size spectrum of macropore-type preferential pathways. Soil Sci. Soc. Am. J.69(4):1196-1208. Langergraber, G. and J. `imunek, Modeling Variably-Saturated Water Flow and Multi- Component Reactive Transport in Constructed Wetlands, Vadose Zone Journal, 4, 924- 938, 2005. Langergraber, G. and J. `imunek, The multi-component reactive transport module CW2D for subsurface flow constructed wetlands, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90-39341125, 18-21, 2005. Lazarovitch, N. J. `imunek, M. Th. van Genuchten, and U. Shani, Numerical Analysis of Soil Limiting Flow from Subsurface Sources, In: S. Torkzaban and S. M. Hassanizadeh (eds.), Proc. of Workshop on HYDRUS Applications, October 19, 2005, Department of Earth Sciences, Utrecht University, The Netherlands, ISBN 90-39341125, 53-56, 2005. Lazarovitch, N., J. `imunek, and U. Shani, System dependent boundary condition for water flow from subsurface source, Soil Sci. Soc. Am. J., 69(1), 46-50, 2005. Lee, J., and F.X.M. Casey. 2005. Development and Evaluation of a Simplified Mechanistic- Stochastic Method for Field-Scale Solute Transport Prediction. 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ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005) (Abstract) Schwärzel, K., J. `imunek, H. Stoffregen, G. Weselek, and M. Th. van Genuchten, Estimation of the unsaturated hydraulic conductivity of peat soils: laboratory versus field data, Vadose Zone Journal, (in press). Shafer, D.S., M.H. Young, S.F Zitzer, T.G. Caldwell, E.V. McDonald. 2005. Impacts of coupled pedogenic, hydraulic, biotic and abiotic processes during the past 125,000 years of landscape evolution in the northern Mojave Desert, Nevada, U.S.A. J. Arid Env. Submitted. Sharma, S. M., Mohanty, B. P., and Zhu, J., Including Topography and Vegetation Attributes for Developing Pedo Transfer Functions in Southern Great Plains, SSSAJ, revised, 2005. Shira, J. M., Williams, B. C., Flury, M., Czigany, S. and Tuller, M., 2005. Sampling silica and ferrihydrite colloids with fiberglass wicks under unsaturated flow conditions. J. Environ. Qual., (in press). SHIRA, J.M., S. CZIGANY, B. WILLIAMS, M. FLURY, M. 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Th. van Genuchten, Contaminant Transport in the Unsaturated Zone: Theory and Modeling, Chapter 22 in The Handbook of Groundwater Engineering, Ed. Jacques Delleur, Second Edition, 2006. `imunek, J., D. Jacques, M. Th. van Genuchten, and D. Mallants, Multicomponent geochemical transport modeling using the HYDRUS computer software packages, In: Institutions for 19 Sustainable Watershed Management: Reconciling Physical and Management Ecology in the Asia-Pacific, Proceedings of the AWRA (American Water Resources Association) Summer Specialty Conference, June 27-29, 2005, Honolulu, HI, American Water Resources Association, Middleburg, VA, 7 p., 2005. `imunek, J., M. Th. van Genuchten, and M. `ejna, The HYDRUS-1D software package for simulating the one-dimensional movement of water, heat, and multiple solutes in variably-saturated media. 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Rhizosphere effects on cesium fixation sites of soil containing micaceous clays. Soil Sci. Soc. Am. J., 69: 1652-1657. Wendling, L. A., Harsh, J. B., Ward, T. E., Palmer, C. D., Hamilton, M. A., Boyle, J. S. and Flury, M., 2005b. Cesium desorption from illite as affected by exudates from rhizosphere bacteria. Environ. Sci. Technol., 39: 4505-4512. Woche, S. K., M.-O. Goebel, M. B. Kirkham, R. Horton, R. R. van der Ploeg, and J. Bachmann. 2005. Contact angle of soils as affected by depth, texture, and land management. European J. Soil Sci. 56: 239-251. Wu, L., J. Letey, C. French, Y. Wood, and D. Birkle. 2005. Nitrate leaching index for irrigated agriculture. J. of Soil & Water Conservation. 60: 90A-95A. Ye, M., Schaap, M. G., Khaleel, R., and Zhu, J., Characterizing Variability in Soil Hydraulic Properties Using Cokriging and Artificial Neural Network, AGU Fall Meeting, San Francisco, USA, December 5 9, 2005. Young, M.H., T.G. Caldwell, J.O. Goreham, D.G. Meadows, D.S. Shafer, J.J. Miller, E.V. McDonald. 2005. Hydrologic impacts of a surface-applied, organic emulsion on arid soils. Presented at the Fall AGU Meeting, San Francisco, CA. Young, M.H., W. Albright, K.F. Pohlmann, G. Pohll, W.H. Zachritz, S. Zitzer, D.S. Shafer, I. Nester, L. Oyelowo. 2005. Incorporating parametric uncertainty in the design of alternative landfill covers in arid regions. Vadose Zone J. Under revision. Zerihun, D. Furman, A., Warrick, A.W., and Sanchez, A.C. 2005. A coupled surface-subsurface flow model for improved basin irrigation management . J. Irrig.Dr. Eng. 131:111-128. DOI: 10.1061/(ASCE)0733-37(2005)131:2(111). 22 Zerihun, D. Furman, A., Warrick, A.W., and Sanchez, A.C. 2005. A coupled surface-subsurface solute transport model for irrigation borders and basins. I. Model development. J. Irrig. Dr. Eng. 131:396-406. DOI: 10.1061/(ASCE)0733-9437(2005)131:5(396). Zerihun, D. Furman, A., Warrick, A.W., and Sanchez, A.C. 2005. A coupled surface-subsurface solute transport model for irrigation borders and basins. I. Model evaluation. J. Irrig. Dr. Eng. 131:407-419. DOI: 10.1061/(ASCE)0733-9437(2005)131:5(407). Zhang, J.X., K-T Chang, J.Q. Wu, 2005. Effects of DEM resolution and source on soil erosion modelling: a case study using the WEPP model, Int. J. Geogr. Info. Sys., (in review). Zhou, J., J. L. Heitman, R. Horton, T. Ren, T. E. Ochsner, L. Prunty, R. P. Ewing and T. J. Sauer. 2005. Method for maintaining one-dimensional temperature gradients in unsaturated, closed soil cells. Submitted to SSSAJ. Zhu, J., and B. P. Mohanty, 2005a. Effective scaling factor for transient infiltration in heterogeneous soils, Journal of Hydrol., in press. Zhu, J., and B.P. Mohanty. 2005b. Effective Soil Hydraulic Parameters for Land-atmosphere Interaction, Water Resources Research, submitted. Zhu, J., and M.H. Young, 2005. Correspondence of hydraulic functions and its implication on upscaling for large scale flux and surface soil moisture in heterogeneous soils, AGU Fall Meetings, December 5 9, San Francisco, California. Zhu, J., B. P. Mohanty, and N. N. Das, 2005a. On the effective averaging schemes of hydraulic properties at the landscape scale, Vadose Zone J., in press. Zhu, J., M.H. Young, C.A. Cooper, and D.A. Devitt, 2005b Modeling Tritium Vapor Transport in Soil Profiles and Subsequent Tritium Uptake by Plants, ASA-CSSA-SSA International Annual Meeting, Salt Lake City, Utah, November 6 10. 23 7. SIGNATURES Mart Oostrom, Chair Technical Committee, W-1188 Date G.A. Mitchell Administrative Advisor, W-1188 Date

Impact Statements

The development of field-scale models by W1188 scientists is a simplified means to identify how solute, such as a pollutant, can transport through a soil and enter the groundwater. Future applications of these techniques will include the identification of aquifer vulnerability.
W1188 scientists continue to enhance the disciplines of soil physics and hydrology by creating a new knowledge base for the next generation of scientists.
Results have revealed important processes in colloid and colloid-facilitated contaminant transport near the gas-solid-water interface and contaminant stripping from colloid carriers and that over long time scales of months and years, colloidal suspensions in the vadose zone are not stable.
The laboratory and field fate and transport studies on various estrogens for following movement of these highly potent hormones and their potential spread through our environment. Our studies are the first to identify how hormones are bound, tranformed, or transported and allow an understanding of how these potentially dangerous substances enter the water supply.
Our data and modeling efforts provide valuable insight toward advancing our understanding of porous media fluid physics in extra-terrestrialgravity environments such as on space craft orbiting earth or traveling to the moon or mars. Fundamental porous media fluid physics research has been a key element of NASAs Advanced Life Support Program for designing plant growth facilities that are part of bioregenerative life support systems for microgravity situations.
This work adrresses a long standing puzzle in soil thermal conductivity as a function of water content and will lead to improved estimates of soil thermal regimes.
In California nurseries, pesticide degradation in recycling ponds is key to protecting the environment from toxic buildup. The committees research found that microbial transformation of pesticides studied was less affected by temperature that by chemical transformation. Overall, the pesticide degradation capacity of recycling ponds was better buffered against temperature changes than in surface stream waters.
We studied tillage effects on bare soil evaporation and near surface soil water and temperature dynamics. The results demonstrated that tillage, independent of residue cover, increases soil water depletion near the surface through accelerated vapor transport and elevated surface heating. Reduction of evaporation vis decreased capillary flow to the surface after shallow tillage is either unimportant or not operative in these soils of west Texas.
Research in Iowa showed mid-season N application was beneficial for recovering some of the potential corn yield but the practice does not benefit water quality compared to single application at emergence. This information will help Midwest farmer make economic decisions on using and timing of fertilizer application that maximize yields and minimize effects on water quality.
A number of improvements in istrumentation under Objective 2 reached fruition in 2005: Fiberglass wicks for colloid sampling from the vadose zone, new design of and construction of permeameter that will provide convenient and rapid measurement of hydraulic conductivity, a new soil cell design to allow improvement in studies measuring coupled heat and moisture transfer, and improved flexibility and accuracy of conventional TDR measurements using variable cable lengths.

Date of Annual Report: 03/28/2007

Report Information

Annual Meeting Dates: 01/02/2007 - 01/04/2007
Period the Report Covers: 10/01/2005 - 09/01/2006

Participants

A.W. Warrick, Department of Soil, Water and Environmental Science,
University of Arizona;W. Rasmussen, Department of Soil, Water and Environmental Science,University of Arizona, Tucson, AZ; P. Ferre, Department of Hydrology and Water Resources, University of Arizona,Tucson, AZ; Marcel Schaap, Dept. of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ;S. A. Bradford, George E. Brown, Jr. Salinity Lab - USDA-ARS, Riverside, CA;T.Harter, Dept. of LAWR, Hydrologic Science, University of California Davis,
CA ; J.W. Hopmans, Dept. of LAWR, Hydrologic Science, University of California
Davis, CA; W.A. Jury, Dept. of Environmental Sciences, University of California, Riverside; D.R. Nielsen, Dept. of LAWR, Hydrologic Science, University of California Davis; P.J. Shouse, George E. Brown, Jr. Salinity Lab - USDA-ARS, Riverside, CA;Z. Wang, Department of Earth and Environmental Sciences, California State University, Fresno, CA; L.Wu, Dept. of Environmental Sciences, University of California, Riverside, CA;L.R. Ahuja, USDA-ARS, Great Plains System Research Unit Fort Collins, CO;T. Green, USDA-ARS, Great Plains System Research Unit Fort Collins, CO;G. Butters, Dept. of Agronomy, Colorado State University, Ft Collins, CO;Y. Jin, Dept. of Plant and Soil Sciences,Univ. of Delaware, Newark, DE;Idaho Markus Tuller, Dept. of Plant, Soils & Environ. Sci. Univ. of Idaho, Moscow, ID;T.R. Ellsworth, University of Illinois, Urbana, IL; J. Cushman, Mathematics Dept., Purdue University, W. Lafayette, IN;P.S.C. Rao, School of Civil Engineering, Purdue University, W. Lafayette, IN;R. Horton, Dept. of Agronomy, Iowa State University, Ames, IA; D. Jaynes, National Soil Tilth Lab, USDA-ARS, Ames, IA; G. Kluitenberg, Dept. of Agronomy, Kansas State University, Manhattan, KS; J. Nieber, Dept. Biosystems and Agricultural Eng., University of Minnesota,St. Paul, MN; . Ochsner, USDA, Agricultural Research Services, St. Paul, MN; J. M. Wraith, Land Resources and Environ. Sciences, Montana State University,Bozeman, MT; T. Caldwell, Desert Research Institute, University of Nevada, Las Vegas, NV; S.W. Tyler, Hydrologic Sciences Graduate Program, University of Nevada, Reno,NV; M.H. Young, Desert Research Institute, University of Nevada, Las Vegas, NV; J.H.M. Hendrickx, New Mexico Tech, Dept. of Geoscience, Socorro, NM;F. Casey, Dept. of Soil Science, North Dakota State University, Fargo, ND; Maria Dragila, Oregon State University, Dept. of Crop and Soil Science,Agriculture and Life Aciences, Corvallis, Oregon;
Tennessee J. Lee, Biosys Engin & Envir Sci., University of Tennessee,Knoxville, TN; E. Perfect, Dept. of Geo. Sciences, Univ. Tennessee Knoxville, TN;S.R. Evett, USDA-ARS-CPRL, P.O. Drawer 10, Bushland, TX; R.C. Schwartz, USDA-ARS-CPRL, P.O. Drawer 10, Bushland, TX; S. Jones, Dept. of Plants, Soils & Biomet., Utah State University, Logan, UT; Washington M. Flury, Dept. of Crop & Soil Sciences, Washington State University, Pullman,WA; J. Wu, Dept. of Biological System Engineering, Washington State University,Pullman, WA; P. D. Meyer, Battelle Pacific Northwest Division, Portland, OR; M. Oostrom, Battelle Pacific Northwest Division, Richland, WA;M. L. Rockhold, Battelle Pacific Northwest Division Richland, WA; A. L Ward, Battelle Pacific Northwest Division, Richland, WA;Z. F. Zhang, Battelle Pacific Northwest Division, Richland WA; Wyoming Thijs Kelleners, Dept. of Renewable Resources, University of Wyoming,
Laramie, WY; CSREES R. Knighton, USDA-CSREES, Washington, DC;Adm. Adv. Jeff Jacobsen, Dean and Director, College of Agriculture, Montana State University, Bozeman, MT

Brief Summary of Minutes

The meeting described in its entirety is located on the website at North Dakota State University: http://www.soilsci.ndsu.nodak.edu/W188/W-188.html

It was discussed that we would hold one more meeting (2008) in Las Vagas and then choose another location (2009).

Accomplishments

To see the complete report with tables: please see our website at: http://www.soilsci.ndsu.nodak.edu/W188/W-188.html Theoretical Re-analysis of Unstable Flow in the Upward and Horizontal Directions and theEffect of Soil Water Repellency: We have continued our studies on unstable flow in porous media. In an early paper by Wang etal., (1998), theoretical derivations of fluid displacement involving immiscible oil, water and air/gas in a porous medium by Chuoke et al. (1959) were generalized. Twenty-four specific criteria for the onset of unstable flow were developed. The downward water flow displacing air in the vadose zone was predicted to be unstable (producing fingers) when the infiltration rate I is< Vgrav -Vcap, where Vgrav is fluid velocity driven by gravity (Vgrav = Ks|cos²|), ² is the angle between the direction of flow and the direction of gravity, Vcap is fluid velocity driven by the capillary forces [Vcap = (0.00015 ~ 5.7)Ks, the coefficient value varies with soil texture ranging from coarse sand to silt clay]. The upward flow was predicted to be unstable when the flow is too fast or if I is > Vgrav+Vcap. The horizontal flow was predicted to be unstable if I is > Vcap. Our reexamination of the complex derivations and parameter definitions by Chuoke et al. (1959) led to a new set of 24 criteria (Javaux et al., 2005). For the upward and horizontal flow of waterdisplacing air in soils, the new criteria predicted unconditional stable flow (unstable only if infiltration rate is negative), consistent with Philips prediction. Further more, we realized that the occurrence of unstable flow is only related to two factors: (i) the position of the heavier fluid in the system (either above or blow the lighter fluid), and (ii) the relative viscosity of the driving fluid (either more or less viscous than the displaced fluid), see the specific criteria in Table 1. Soil water repellency was not a factor influencing the instability criteria. Tests are still needed to verify some of the new criteria. In addition, a review paper on finger flow studies was published in a Chinese journal SOIL (Li et al., 2006). This will promote awareness of theoretical and experimental studies in China. Further studies are being proposed. Characteristic Curves of Two Wettable Soils and Matched Hydrophobized counterparts: Accomplishments. A study was performed to examine the dry end of the soil water retention curve where surface adsorption is the critical component in determining the amount of water retained. Two naturally hydrophilic soils were used. Two additional soils were studied by hydrophobizing the two naturally hydrophilic soils with dichloromethylsilane. Two methods were used to measure wetting and drying curves of the soils. The vapor equilibration method was applied to soil samples contained in air space above salt(NaCl) solutions to achieve equilibrium at selected osmotic potentials. Soil samples were allowed to equilibrate starting with relatively dry (wetting curves) or wet (drying curves) conditions. The second method is known as the controlled water content method. Water was either added to soil samples to achieve known water content (wetting curves), or initially saturated soil samples were dried by evaporation to obtain the desired water content (drying curves). The equilibrium water potentials associated with the different soil watercontents were measured with a Decagon WP4 DewPoint Potentiometer. Outcome. Overall, soil water hysteresis was not observed. We hypothesize that a decrease in osmotic potential occurred during the hydrophobizing process due to mineral dissolution.Water droplets were visible on the surface of the hydrophobic soil samples indicating not only their hydrophobicity but also the impact of solute. Surface and subsurface solute transport properties at row and inter-row positions: Accomplishments. Although numerous studies have investigated the effects of crop production practices on soil water dynamics, not much information is available on the impact of row position on solute transport. A field experiment was carried out to evaluate surface and subsurface solute transport properties in plant-row, non-trafficked inter-row, and trafficked interrow positions. For this purpose, a plot of 14- by 14-m in a strip-cropped field with soybean (Glycine max L. Merr ), corn (Zea mays L.), and oat (Avena L.) was selected. After harvesting the crops, surface (top 2 cm) electrical conductivity measurements were made by time domain reflectometry (TDR) at 45 locations during a chloride pulse leaching experiment. At the conclusion of the pulse leaching experiment, 120-cm deep soil cores were collected at the 45 locations in order to measure the soil profile chemical distributions. Outcome. No crop or rowposition effects were observed for surface determined pore water velocities (v), while profile determined v was greater in plant row vs. inter-row positions when averaged over all crops. Overall, the profile determined v was slightly greater than the surface determined v, probably because of lower effective or mobile water contents. The profile determined dispersion oefficient (D), was smaller in row positions than inter-row positions in soybean and corn,perhaps because of surface ponding in the inter-row positions of the crops resulting in macropore flow. Profile determined D was greater in the inter-row positions of soybean than oat, againreflecting possible macropore flow. Overall, the mean soil profile dispersivity (³ = 2.97 cm) was larger than the surface soil ³ (1.02 cm). Impact. The local surface solute transport varied by row positions while profile solute transport was affected by both row position and crop perhaps due to surface ponding producing macropore flow in the trafficked and non-trafficked inter-rows of soybean and the trafficked inter-rows of corn. Thus, a one-dimensional solute transport modelwith a spatially distributed flux or potential controlled upper boundary condition must be used to model this system. Field Gas Transport Processes: A fundamental understanding of the gas transport processes in soils, and their coupling to the atmosphere, is crucial for assessing the aeration properties of soil profiles, and for investigation of sequestration/release phenomena important to greenhouse gases. Soil gas transport properties are chiefly determined by the effective diffusion coefficient (Ds). Many models exist relating Ds to physical and environmental soil properties, such as the soil volumetric water content, texture,and structure. However, these models may not be applicable in field conditions, due to the heterogeneity of soil profiles, or to other conditions such as the seasonal presence of a snow cover. Outcome: Montana is engaged in a comprehensive field project to investigate the evolution and emission of greenhouse gases in a forested mountain watershed environment. The first part of the project seeks to evaluate different methods for measuring and/or monitoring the gaseous diffusion coefficients for soils and associated snow cover in the field, and the resulting gas efflux to the atmosphere. Characteristics of both soil and snow which affect their diffusional gas transport properties change in space and with time, including the temperature and wetness which also impact microbial activities critical to production and consumption. Optimizing a Root Zone Soil System: Rigorous management of restricted root zones utilizing coarse-textured porous media greatly benefits from optimizing the gas-water phase balance within plant-growth media. Geophysical techniques can help to quantify root-zone parameters like water content, air-filled porosity,temperature and nutrient concentration to better address the root systems performance. Due to 26 the high root densities and limited volumes of restricted root zones the efficiency of plant growth is critically linked to maintaining favorable water content/air-filled porosity balance while considering adequate fluxes to replenish water at decreasing hydraulic conductivities during uptake. The supply of nutrients to the volumes adjacent to roots also needs to be optimized to provide adequate supplies during each period of the plants life cycle avoiding build-up of excessive nutrient concentrations. Our objectives were to (1) design and model an optimized root zone system using optimized porous media layers, (2) verify our design by monitoring the water content distribution and tracking nutrient release and transport within the porous medium. We developed a unique root zone system using layered Ottawa sands promoting more uniform water content (and air-filled porosity) within the column profile. Watering was achieved by maintaining a shallow saturated layer at the bottom of the column and allowing capillarity to draw water upward, first through coarser particle sizes in the bottom layer with finer particles sizes forming the layers above. The depth of each layer was designed to optimize water content based on measurements and modeling of the wetting water retention curves. Layer boundaries were chosen to maintain saturation between 50 and 85 percent. The vertical water content distribution was verified by dual-probe heat-pulse water content sensors and finally bydestructive sampling. The nutrient experiment involved embedding slow release fertilizer in theporous media in order to detect variations in electrical resistivity versus time during the release, diffusion and uptake of nutrients. The experiment required a specific geometry for the acquisition of ERT data using the heat-pulse water-content sensors steel needles as lectrodes. ERT data were analyzed using the sensed water contents and deriving pore-water resistivities using Archies law. The proposed plant-growth medias design and monitoring capabilities offers an efficient means to describe the effects of the root systems performance on plant growth and links porous media physics with in-situ monitoring.The effect of a hydrophobic layer on the upward movement of water during freezing:Accomplishments: Laboratory experiments were performed to compare upward watermovement from a fixed water table during freezing for soils with and without a hydrophobic Content (g g-1)Height (cm)untreated soilhydrophobic layerFig 1. Water content distributions for soil with and without a hydrophobic layer after 30 d freezing conditions at the upper boundary.30 layer. A 20-cm length soil column was developed to enable one-dimensional vertical heat flow by including a column-within-a-column design that minimizes radial heat transfer. Upperboundary temperature was maintained at -6 °C with a heat exchanger; transient temperature distributions and water uptake were measured for 30 d. Ice and water distributions were determined by sampling at the conclusion of the experiment. Outcome. The hydrophobic layer had a significant effect on liquid water movement during freezing (Fig. 4). Some water redistribution occurred above the hydrophobic layer, but little water was drawn upward from the water table. The reduced water movement resulted in deeper freezing but less frost heave. Surface and subsurface solute transport properties at row and inter-row positions:Accomplishments. Although numerous studies have investigated the effects of crop production practices on soil water dynamics, not much information is available on the impact of row position on solute transport. A field experiment was carried out to evaluate surface and subsurface solute transport properties in plant-row, non-trafficked inter-row, and trafficked interrow positions. For this purpose, a plot of 14- by 14-m in a strip-cropped field with soybean(Glycine max L. Merr ), corn (Zea mays L.), and oat (Avena L.) was selected. After harvestingthe crops, surface (top 2 cm) electrical conductivity measurements were made by time domain reflectometry (TDR) at 45 locations during a chloride pulse leaching experiment. At the conclusion of the pulse leaching experiment, 120-cm deep soil cores were collected at the 45 locations in order to measure the soil profile chemical distributions. Outcome. No crop or row position effects were observed for surface determined pore water velocities (v), while profile determined v was greater in plant row vs. inter-row positions when averaged over all crops.Overall, the profile determined v was slightly greater than the surface determined v, probably because of lower effective or mobile water contents. The profile determined dispersion coefficient (D), was smaller in row positions than inter-row positions in soybean and corn,perhaps because of surface ponding in the inter-row positions of the crops resulting in macropore flow. Profile determined D was greater in the inter-row positions of soybean than oat, again reflecting possible macropore flow. Overall, the mean soil profile dispersivity (³ = 2.97 cm) was larger than the surface soil ³ (1.02 cm).

Publications

Abdu, H. D.A. Robinson and S. B. Jones. 2006. Comparing Bulk Soil Electrical Conductivity Determination Using the DUALEM 1-S and EM-38DD EMI Instruments. Accepted in Soil Sci. Soc. Am. J. Albright, W.H., C. H. Benson, G. W. Gee, T. Abichou, E. V. McDonald, S. W. Tyler, and S. A. Rock. 2006. Field Performance of a Compacted Clay Landfill Final Cover at a Humid Site, J. Geotech. and Geoenvir. Engineering. 132:1393-1399 Albright, W.H., C. H. Benson, G. W. Gee, T. Abichou, S. W. Tyler, and S. A. Rock. 2006. Al-Jabri, S.A., J. Lee, A. Gaur, R. Horton and D.B. Jaynes. 2006. A dripper-TDR method for in situ determination of hydraulic conductivity and chemical transport properties of surface soils. Adv. Water Resour. 29: 239-249. Bachmann, J., G. Arye, M. Deuer, S. K. Woche, R. Horton, K. H. Hartge, and Y. Chen. 2006. Universality of a surface tension contact angle relation for hydrophobic soils of different texture. J. Plant Nutr. Soil Sci. 169: 745-753. Bahaminyakamwe, L., J. `imonek, J. Dane, J. F. Adams, and J. W. Odom, Copper mobility in soils as affected by sewage sludge and low molecular weight organic acids, Soil Sci., 171(1), 29-38, 2006. Bakhsh, A., R. Kanwar, D.B. Jaynes, T.S. Colvin, and L.R. Ahuja. 2005. Modeling precision agriculture for better crop productivity and environmental quality. Asian Assoc. Agricult. Eng. 14:235-243. Berli, M and Or, D., 2006. Deformation of spheroidal pores in viscoplastic soil material. International Journal of Geomechanics, 6(2), 108-118. Berli, M. Eggers, C.G., Accorsi, M. and Or, D., 2006. Theoretical analysis of mechanical behavior of fluid inclusions for in-situ measurements of soil stress and deformation. Soil Science Society of America Journal, (in press). Berli, M., Accorsi, M.L. and Or, D., 2006. Size and shape evolution of pores in viscoplastic matrix under compression. International Journal for Numerical and Analytical Methods in Geomechanics, (in press). Blonquist, J.M. Jr., S.B. Jones and D.A. Robinson. 2006. Water Conservation from Precise Irrigation Scheduling Using a Subsurface Electromagnetic Soil Moisture Sensor. Ag. Water Management 84:153-165. Blonquist, J.M. Jr., S.B. Jones, I. Lebron and D.A. Robinson. 2006. Micro-structural and phase configuration effects determining water content: Dielectric relationships of aggregated porous media. Water Resour. Res. 42(5), W05424, doi:10.1029/2005WR004418. Boivin, A., J. `imonek, M. Schiavon and M. Th. van Genuchten, A comparison of pesticides transport processes in three contrasting field soils using Hydrus-2D, Vadose Zone Journal, 5, 838849, 2006. Boivin, A., J. `imonek, M. Schiavon, and M. Th. van Genuchten. 2006. Comparison of pesticide transport processes in three tile-drained field soils using HYDRUS-2D. Vadose Zone J. 5(3): 838-849. Bondarenko, S., Zheng, W., Yates, S.R., and Gan, J. 2006. Dehalogenation of halogenated fumigants by polysulfide salts. Journal of Agricultural & Food Chemistry. 54:5503-5508. 77 Bradford, S. A., and M. Bettahar. 2006. Concentration dependent colloid transport in saturated porous media. J. Contaminant Hydrology, 82:99-117. Bradford, S. A., J. `imonek, and S. L. Walker, Transport and straining of E. coli O157:H7 in saturated porous media, Water Resour. Res., 42, W12S12, doi:10.1029/2005WR004805, 12 pp., 2006. Bradford, S. A., J. Simunek, and S. L. Walker. 2006. Transport and deposition of E. coli O157:H7 in saturated porous media. Water Resources Research, 42, W12S12, doi:10.1029/2005WR004805. Bradford, S. A., J. Simunek, M. Bettahar, M. Th. van Genuchten, and S. R. Yates. 2006. Significance of straining in colloid deposition: Evidence and implications. Water Resources Research, 42, W12S15, doi:10.1029/2005WR004791. Bradford, S. A., J. `imonek, M. Bettahar, M. Th. van Genuchten, and S. R. Yates, Significance of straining in colloid deposition: evidence and implications, Water Resour. Res., 42, W12S15, doi:10.1029/2005WR004791, 16 pp., 2006. Bradford, S. A., Y. F. Tadassa, and Y. Jin. 2006. Transport of coliphage in the presence and absence of manure suspension. Journal of Environmental Quality, 35, 1692-1701. Bradford, S. A., Y. F. Tadassa, and Y. Pachepsky. 2006. Transport of Giardia and manure suspensions in saturated porous media. Journal of Environmental Quality, 35, 749-757. Bradford, S.A., Simunek, J., Bettahar, M., van Genuchten, M.Th., S.R. Yates. 2006. Significance of straining in colloid deposition: Evidence and implications. Water Resources Research. 42 (12): Art. No. W12S15 Cable-Rains, M., G. E. Fogg, T. Harter, R. A. Dahlgren, and R. J. Williamson, 2006. The role of perched aquifers in hydrological connectivity and biogeochemical processes in vernal pool landscapes, Central Valley, California. Hydrol. Process. 20, 11571175. Caldwell, T.G. E.V. McDonald, M.H. Young. 2006. Soil disturbance and unsaturated hydraulic response at the National Training Center, Ft. Irwin, California. J. Arid Env. 67:456-472. Caldwell, T.G., E.V. McDonald, and M.H. Young. Soil water balance, seedbed microclimate, and the revegetation of disturbed lands in the Mojave Desert, In R. H. Webb, et al., eds. The Mojave Desert: Ecosystem Processes and Sustainability. University of Nevada Press, Reno, NV. In Press Carrillo-González, R., J. `imonek, S. Sauve, and D. Adriano, Mechanisms and pathways of trace element mobility in soils, Advances in Agronomy, 91, 111-178, 2006. Casey, F.X.M., G.L. Larsen, H. Hakk, and Z. Fan. 2006b. The Fate of Manure-Borne, Land- Applied Hormone. In Annual Meetings Abstracts, Division S11 Symposium [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Casey, F.X.M., N.E. Derby, and D.W. Franzen. 2006a. Comparison of nitrogen management zone delineation methods for corn grain yield 8th International Conference on Precision Agriculture and Other Precision Resources Management. July 2006, Minneapolis, MN. Castiglione, P., P.J. Shouse, and J.M. Wraith. 2006. Multiplexer-induced interference in TDR measurements of electrical conductivity. Soil Sci. Soc. Am. J. 70:1453-1458. Chen, L. M.H. Young. 2006. Green-Ampt model for sloping surfaces. Water Resour. Res., Vol. 42, No. 7, W07420. Chuoke, R. L., P. van Meurs, and C. van der Poel, The instability of slow, immiscible, viscous liquid-liquid displacements in permeable media, Trans. Am. Inst. Min. Metall. Pet. Eng., 216, 188-194, 1959. 78 Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. Cotton production with SDI, LEPA, and spray irrigation in a thermally-limited climate. International Water & Irrigation. 26(1):10-12, 14. Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. Crop emergence and near-surface soil temperature for SDI, LEPA, and spray irrigation. In: Proceedings of the ASABE Annual International Meeting, July 9-12, 2006, Portland, Oregon. 2006 CDROM. Paper No. 062278. Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. Near-surface soil water and temperature for SDI, LEPA, and spray irrigation. In: Irrigation Association Conference Proceedings, November 5-7, 2006, San Antonio, Texas. 2006 CDROM. Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. SDI bed design comparison for soybean emergence and yield. In: Proceedings of the ASABE Annual International Meeting, July 9-12, 2006, Portland, Oregon. 2006 CDROM. Colaizzi, P.D., Evett, S.R., Howell, T.A., Tolk, J.A. 2006. Comparison of five models to scale daily evapotranspiration from one-time-of-day measurements. Transactions of the ASABE. 49(5):1409-1417. Colaizzi, P.D., Evett, S.R., Howell, T.A., Tolk, J.A., Li, F. 2006. Evaluation of a two-source energy balance model in an advective environment. In: Proceedings of the World Water and Environmental Resources Congress. Examining the Confluence of Environmental and Water Concerns, May 21-25, 2006, Omaha, Nebraska. 2006 CDROM. Colaizzi, P.D., Lamm, F.R., Howell, T.A., Evett, S.R. 2006. Crop production comparison under various irrigation systems. 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Cady, Information content and complexity of simulated soil water fluxes, Geoderma, 134, 253-266, 2006. Pachepsky, Y., A. Guber, D. Jacques, J. `imonek, M. Th. van Genuchten, T. Nicholson, and R. Cady. 2006. Information content and complexity of simulated soil water fluxes. Geoderma 134: 253-266. Panagopoulos, G., and N. Lambrakis. 2006. The contribution of time series analysis to the study of the hydrodynamic characteristics of the karst systems: Application on two typical karst aquifers of Greece (Trifilia, Almyros Crete). J. Hydrol. 329:368-376. Pang, L. and J. `imonek, Evaluation of Bacteria-Facilitated Cadmium Transport in Gravel Columns using the HYDRUS Colloid-Facilitated Solute Transport Model, Water Resour. Res., 42, W12S10, doi:10.1029/2006WR004896, 2006. Pang, L., C. Nokes, J. `imonek, H. Kikkert, and R. Hector, Modeling the impact of clustered septic tank systems on groundwater quality, Vadose Zone Journal, 5, 599-609, 2006. Persson, M., J.M. Wraith, and T. Dahlin. 2006. A small-scale matric potential sensor based on time domain reflectometry. Soil Sci. Soc. Am. J. 70:533-536. Peters, R.T., Evett, S.R. 2006. A fully automated center pivot using crop canopy temperature: Preliminary results. Ground Water and Surface Water Under Stress: Competition, Interaction, Solutions. A USCID Water Management Conference, October 25-28, 2006, Boise, Idaho. p 139-148. Peters, R.T., Evett, S.R. 2006. Center-pivot automation using crop canopy temperature to eliminate irrigation guesswork. Resource Engineering and Technology for a Sustainable World. 13(2):9-10. Pieri, L., Bittelli, M., Wu, J.Q., Dun, S., Flanagan, D.C., Rossi Pisa, P., Ventura, F., and Salvatorelli, F., 2006. Using the Water Erosion Prediction Project (WEPP) model to simulate field-observed runoff and erosion in the Apennines Mountain Range, Italy, J. Hydrol. (accepted) Pikul Jr, J.L., Schwartz, R.C., Benjamin, J.G., Baumhardt, R.L., Merrill, S.D. 2006. Cropping systems influences on soil physical properties in the great plains. Renewable Agriculture and Food System. 21(1):15-25. Poch, R.M., J.W. Hopmans, J. Six, D.E. Rolston, J.L. MacIntyre. 2006. Considerations of a field-scale carbon budget for furrow irrigation. Agriculture, Ecosystems and Environment 113:391-398. Raats, P.A.C., and M. Th. van Genuchten. 2006. Milestones in soil physics, Soil Sci. 171S1: S21-S28. Ramos, T. B., M. C. Gonçalves, J. C. Martins, M. Th. van Genuchten, and F. P. Pires. 2006. Estimation of soil hydraulic properties from numerical inversion of tension disk infiltrometer data. Vadose Zone J. 5: 684-696. Ritchie, J.T., and J.E. Adams, Field Measurement of Evaporation from Soil Shrinkage Cracks, Soil Science Society of America, 38, 131134, 1974 Robinson, D.A., S.B. Jones and S.P. Friedman. 2006. Modeling Structural and Thermal Effects on TDR Measurements in Granular Porous Media. 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Impacts of coupled pedogenic, hydraulic, biotic and abiotic processes during the past 125,000 years of landscape evolution in the northern Mojave Desert, Nevada, U.S.A. J. Arid Env. Accepted. Sharma, S. M., Mohanty, B. P., and Zhu, J., Including Topography and Vegetation Attributes for Developing Pedo Transfer Functions in Southern Great Plains, Soil Science Society of America Journal, 70, 1430-1440, 2006. SHIRA J.M., B.C. WILLIAMS, M. FLURY, S. CZIGANY, and M. TULLER, 2006. Sampling silica and ferrihydrite colloids with fiberglass wicks under unsaturated conditions. J. Environ. Qual., Vol. 35, No. 4, 1127-1134. Shira, J. M., Williams, B.C., Flury, M., Czigany, S. and Tuller, M., 2006. Sampling silica and ferrihydrite colloids with fiberglass wicks under unsaturated flow conditions. J. Environ. Qual., 35: 11271134. Shouse, P.J., Goldberg, S., Skaggs, T.H., Soppe, R.W.O., Ayars, J.E., 2006. 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Impact Statements

Our optimized design for plant rooting media is being considered for a 500 day Mars Mission Chamber test to be carried out by the Russian Space Agency. The benefit of our design is that it provides water content levels more closely related to the expected microgravity root zone environment expected in space. This approach has potential benefit for water and fertilizer savings in greenhouse and horticultural industries.
The local surface solute transport varied by row positions while profile solute transport was affected by both row position and crop perhaps due to surface ponding producing macropore flow in the trafficked and non-trafficked inter-rows of soybean and the trafficked inter-rows of corn. Thus, a one-dimensional solute transport modelwith a spatially distributed flux or potential controlled upper boundary condition must be used to model this system.
Most current measurement and estimation methods for gas transport and emission from soils are based on assumed uniform soils having uniform moisture distribution, and with negligible concurrent production or adsorption of gas. We are analyzing the effective gas transport properties of field soil and snow cover profiles using conventional in situ and laboratory measurement approaches. We are also investigating the potential impacts of non-uniform soil conditions and concurrent biotic activity through numerical simulation of gas evolution and transport processes. For the latter we utilize field and laboratory measurements as well as the Hydrus 1-D code to simulatetransport phenomena under different field scenarios.
Our results have revealed important processes that may help identify unstable displacement during water/oil flow and contaminant transport in the vadose zone and variably saturated aquifers.
Further research is needed to separate the osmotic effects and wettability effects on the water retention for the hydrophobic soils.

Date of Annual Report: 02/26/2008

Report Information

Annual Meeting Dates: 01/02/2008 - 01/04/2008
Period the Report Covers: 10/01/2006 - 09/01/2007

Participants

Bradford, Scott USDA-ARS, Salinity Lab, Riverside, CA
Dragila, Maria Oregon State University, OR
Harter, Thomas Univ. of California, Davis, CA
Hopmans, Jan Univ. of California, Davis, CA
Horton, Bob Iowa State University, Ames, IA
Jacobsen, Jeff (Advisor W-1188) Montana State University, Bozeman, MT
Jones, Scott Utah State University, Logan, UT
Kelleners, Thijs Univ. of Wyoming, Laramie, WY
Kluitenberg, Gerard Kansas State University, Manhattan, KS
Knighton, Ray CSREES-USDA, Washington, DC
McGlynn, Brian Montana State University, Bozeman, MT
Nieber, John Univ. of Minnesota, St. Paul, MN
Nielsen, Donald R. Univ. of California, Davis
Ochsener, Tyson USDA-ARS, St. Paul, MN
Schaap, Marcel Univ. of Arizona, Tucson, AZ
Simunek, Jirka Univ. of California, Riverside, CA
Tuli, Atac Univ. of California, Davis, CA
Tuller, Marcus Univ. of Arizona, Tucson, AZ
van Genuchten, Rien USDA-ARS, Salinity Lab, Riverside, CA
Warrick, Art Univ. of Arizona, Tucson, AZ
Wendroth, Ole Univ. of Kentucky, Lexington, KY
Wraith, Jon Montana State University, Bozeman, MT
Wu, Laosheng Univ. of California, Riverside, CA
Young, Michael Desert Research Institute DRI, Las Vegas, NV
Zhang, Fred Batelle Pacific NW National Lab, Richland, WA

Guests:
Botros, Farag Univ. of California, Davis, CA
Arye, Gilboa Univ. of California, Riverside, CA
Ochiai, Naoyuki Oregon State University, OR
Chief, Karletta Desert Research Institute DRI, Las Vegas, NV
Ghezzehei, Teamrat Lawrence Berkeley Natl. Lab., CA
Hou, Zhenan Univ. of California, Riverside, CA
Iassonov, Pavel Univ. of Arizona, Tucson, AZ
Leising, J.F. Southern Nevada Water Authority, NV
Segal, Eran USDA-ARS, Salinity Lab, Riverside, CA
Siyal, Altaf Ali USDA-ARS, Salinity Lab, Riverside, CA
Kamai, Tamir Univ. of California, Davis, CA
Torkzaban, Saeed Univ. of California, Riverside, CA
Twarakavi, Navin Univ. of California, Riverside, CA
Yang, Changbing Utah State University, Logan, UT
Zhu, Jianting Desert Research Institute DRI, Las Vegas, NV

Brief Summary of Minutes

The budget was signed by the President on Dec. 26, 2007. The CSREES budget fared pretty well. The Hatch budget stayed the same which means a net decrease of 0.65 % after an across-the-board recission. Approximately $150 M in special grants were added to the budget after being deleted last year. NRI funding will be the same as last year, i.e., $ 190 Mio. The NRI water program will again have $4.5 M, the 406 Integrated water program will have about $12.5 M, the soil program about $4 M, and 5 Mio-$ will be available in the Air Quality program (topics are related to: soil atmosphere exchange with gases). The Air Quality program had a success rate of 26 % in 2007. In order to obtain more focused and problem-specific proposals, there is a tendency in many programs to ask investigators to submit letters of intent prior to the main proposal application. There is no Farm bill, yet. It is proposed that CSREES will undergo changes in the next farm bill. CSREES will probably be renamed to the National Institute of Food and Agriculture.

Thomas Harter Chair, Year 2007 Business meeting: Jan Hopmans moves to approve the report for the year 2006 and the minutes of the meeting in 2007, Mike Young seconds, workgroup unanimously approves the annual report for the year 2006 and minutes for the meeting in 2007. Committee nominates two candidates for becoming the next secretary: Marcus Tuller (8), Arizona, and Scott Jones (6), Utah. Markus was approved by the committee, and he accepts.

Jeff Jacobsen, Administrative Report: The current project phase will expire in 2009. Therefore, this will be a writing year. In general, one or two year extensions of project would be possible. Plan ahead necessary with core group. The objectives will need to be addressed in project presentations. For reviews of the projects, accomplishments and impacts need to be specifically addressed. Besides publications, investigators should tell the differences, as a result of their research. Other funding than through this project should be identified and clearly mentioned in project reports. Others have access and use the databases, now. In the future, more people will be looking for accountability. A long list of publications may not necessarily be satisfying. Impact statements may in some cases be valued rather than pure numbers of publications. Ray Knighton: An important criterion will be, how many new technologies were developed and adopted besides publications. Currently, Experiment Station Directors think of hiring staff that is able to write those impact statements.

Laosheng Wu, Objective is to evaluate fate and transport of pharmaceutical products, especially DBPs and PCCPs in reclaimed water which is used for turfgrass irrigation. A lysimeter was established in the center of each of 12 plots. Water with 11 selected compounds was applied at two rates, approximately 1.15 and 1.55 ET0, irrigation with sprinklers, free drainage bottom boundary, leachate collected and analyzed (solid phase extraction) twice a week. Recovery of compounds in water samples between 75 and 122 %. Future work will be directed towards adsorption of PPCBs and DBPs in soil, and their interception by turfgrass.

Tyson Ochsener, Soil heat flux so far has mainly been quantified under unfrozen soil conditions. This study should show whether heat flux sensing is also possible during freezing/thawing processes. This focus is relevant for many locations in the U.S., and its implications regard the surface energy balance, hydrologic processes, gas emissions, and land surface schemes on global climatic models. This leads to the apparent heat capacity equation, and the apparent heat capacity Ca and apparent thermal conductivity »a, the latter including latent heat flux due to thermally-driven liquid water flow. When the ambient temperature approaches the freezing point, the temperature increase will be lower because most of the heat goes into the phase change. The time tm to the maximum temperature increase Tm is determined from heat pulse curves in frozen soils. The heat capacity C is inversely related to Tm, the thermal diffusivity ± is inversely related to tm, and the thermal conductivity is of course the product of C and ±.

Michael Young, The pedologic development of desert soils dominated by pavement and dust deposition causes a substantial temporal change of soil hydraulic conductivity K. Hydraulic conductivity in the surface soil decreases by about two orders of magnitude whereas in the subsurface it remains rather constant. As a consequence of decreasing surface layer K, the surface runoff potential increases. The questions underlying this project were whether we can use our knowledge of pedology and hydrology to better predict surface runoff potential on arid alluvial fans, and whether a site-specific characterization approach based on pedo-transfer functions would help predicting runoff from individual alluvial fans or groups of fans. A project was established in the Windmill watershed (Bunkerville, NV) where an example area was mapped and the DEM was established. For dry bulk density (BD) and saturated hydraulic conductivity Ks, four statistical groups were derived from the results: The young soils (Qf1/2) resulted in the largest BD and Ks-values. Dissected and eroded pavements (QTt) yielded the lowest BD but higher Ks-values. The lowest Ks-values were observed in the intact pavements (Qf4). In the future, other alluvial fans will undergo the same analysis, soil surface and geomorphic properties will be applied for water resource management, and regionally relevant PTFs will be developed.

Marcel G. Schaap, The motivation of this study was to simulate fluid behavior in porous media at scales between 1 cm to 1 km. Usually, macroscopic transport characteristics such as the water retention curve, hydraulic conductivity function and diffusion-dispersion and partitioning coefficients are applied in the Darcy, Richards, and advection-dispersion equation. The main underlying questions were (referring to the Water Resources Research paper on simulating the soil water retention curve using Lattice Boltzmann model): How applicable is this concept at a larger scale? This problem was addressed in a study at the Hanford site, at which single-walled tanks are stored containing waste material with high pH values. A salt was injected and its migration studied. How are macroscopic properties related to pore-scale physics. Using CT fluid behavior at the pore scale, the pressure-saturation relationship as well as the interfacial area, curvature, and contact angle should be observed.

Naoyuki Ochiai, Most of the studies on transport of Phytophtora zoospores (somewhat larger than bacteria) through porous media being conducted in the 1950s and 60s were performed under water-saturated conditions. In this project transport of zoospores should be performed under real-world, i.e., unsaturated soil conditions. The ideal colloid and zoospore transport behavior, and that of motile and immotile zoospores should be investigated in paired column and micromodel column experiments. Results are interpreted that those colloids exploring low-velocity zones become severly retarded and contribute to tailing, while those moving in high-velocity zones move at greater than average velocity and contribute to early breakthrough. Questions addressed by the investigators for the future regard whether 2D models would reflect 3D geometry adequately, whether these pore-scale processes could be upscaled to explain breakthrough behavior at the macro-scale, and what other mechanisms may result in exclusion.

Eran Segal, In this study, the transport behavior of nitrate and pathogens at a dairy lagoon application site should be investigated as it is relevant for understanding contaminant and bacterial behavior in the environment. The objectives were to derive experimental site characteristics for being used as input for CDE- and MI-transport models. Solute transport parameters measured at the core scale should be validated at the field plot scale. The impact of channels created by decaying roots on transport parameters should be evaluated. In an undisturbed plot with four access rings (1 m diameter) in each corner, 48 tensiometers, 10 neutron access tubes, 48 solution and microbe samplers, and eight four-probe sensors (ECa) were installed. Soil is characterized as a sandy loam with an undulating sand layer underneath, followed by clay lenses.

Scott Bradford, The advectivion-dispersion equation is considered with a first-order deposition and release which can be applied to filtration theory if the release coefficient is considered 0. By solving the flow field using the Navier Stokes equation, the colloid interaction with the solid surface is manifested by the ±-term in the equation which is a chemical interaction term. Alternatively, the DLVO theory describes the chemical interaction between colloids and the solid surface where the magnitude of the energy barrier decreases with decreasing colloid size. Filtration theory neglects the balance of applied and adhesive torques on colloids affecting deposition, and it neglects pore space geometry. The flow field around a single solid grain is considered here: Only a certain fraction of the solid surface will contribute to the retention of the colloid, resulting in a different flow field. The surface area available or favorable for attachment increases with the adhesive force and the resulting torque. Due to the flow field in pore space, a single sphere causes unfavorable conditions for colloid retention, and two spheres unfavorable or even highly unfavorable conditions. Micromodel experiments reveal that the current model does not adequately describe colloid retention.

Scott Jones, Over a temperature range between -10 and 30 °C, three TS1 sensors and soil moisture sensors were tested in a sand column and under constant water content conditions in time. These tensiometers are supposed to purge and refill themselves. The purging simply did not work. All 24 of these 1st generation sensors needed a variety of repairs and updates, and all those three that were tested here were repaired and updated. The main motivation behind this project was to tie an EC map of a 41-ha-watershed into the ecohydrology of that watershed and a vegetation map. A mosaic of trees, shrubs and grasses was digitized, and soil texture was sampled at 40 points. An EC map and 312 TDR soil surface water contents were obtained with a portable instrument within one day. The vegetation distribution to a large extent depends on the local moisture conditions and water content distributions, which again depends on soil texture. The coefficient of determination between EC and both clay and water content was 0.73. The question whether the clay and water content on EC could be sorted out, was answered with the suggestion to map EC at different times and water contents during the year.

Ole Wendroth, Impact of timing of salt or chemical application relative to subsequent rainfall and rainfall amount and intensity on solute leaching has not been studied intensively at the field scale. A pilot study was performed where a KBr tracer was applied to the soil surface in the field. Soil cores taken every 25 cm in horizontal distance were divided into 10-cm-depth increments and samples analyzed for soil water content and total anion concentration. The objective was to study spatial autocorrelation behavior, and spatial relations across different depths with crosscorrelation. Through prior irrigation, initial soil water content differed systematically in the profile. Except for the uppermost compartment (0-10 cm depth) anion concentrations were spatially autocorrelated to a distance of 1 m down to 40 cm soil depth. Below, anion concentrations were very low, and bromide had probably not moved that deep. Anion concentrations were spatially crosscorrelated across 1 m for subsequent soil depths above 50 cm.

Fred Zhang, The motivation for this study was the fact that the soil of the Hanford formation is spatially anisotropic (vertical/horizontal), and this anisotropy is water-saturation dependent. Isotropic soil field-scale hydraulic conductivity can be described using a geometric mean or an upscaled value. Layered soils may be described in the horizontal dimension by the arithmetic mean, and in the vertical dimension with the harmonic mean, whereas stratified soils can be represented in stochastic approaches. In this study, anisotropy should be described using a tensorial connectivity-tortuosity (TCT) concept. The vertical conductivity is user-defined, and the horizontal is the product of the vertical and a connectivity coefficient C. Depending on the degree of anisotropy, C varies. This concept was applied in an injection experiment in a 16 by 16 m experimental field with four transect crossing each other in the central point and having an angle of 45, 90 and 135 ° to each other. For future research, critical knowledge gaps would be upscaling methodologies of the hydraulic conductivity function, and the directional measurement of the hydraulic conductivity function.

Saeed Torkzaban, The problem considered in this study is related to transport of pathogenic bacteria in the subsurface, and riverbank filtration. The colloid filtration theory is based on above-mentioned work of Scott Bradford on colloid (or bacteria) retention (DLVO theory). With increasing distance from the solid surface, the interaction energy increases, however, in close proximity to the surface, unfavorable conditions for bacteria retention exist. Mechanisms for bacteria retention under unfavorable conditions should be investigated in column experiments and under different ionic strengths. Breakthrough curves after a pulse input indicated the strongest retention under highest ionic strength. Hence, if the secondary minima are eliminated, deposited bacteria will be released. However, mass balance calculations in elution experiments showed, that deposition in a secondary energy minimum is not the only mechanism. Bacteria retention in porous media strongly depends on solution chemistry, pore structure, and system hydrodynamics. How does the region change with velocity, does it go up with velocity or not? Under laminar flow conditions, the size of the region does not change. However, the assumption of laminar flow may not be valid. Moreover, attention to streaming potential might become necessary.

Jianting Zhu, Based on the previous years findings, effective hydraulic parameters can be outside of arithmetic and harmonic mean. Here, the question of interest was, if the effective saturated hydraulic conductivity is assumed to be either arithmetic or harmonic mean, depending on the flow direction, will the arithmetic or harmonic mean still work for unsaturated flow? In the underlying theory for local scale considerations, constant capillary pressure head is assumed on top, and zero capillary pressure head at the bottom. Effective hydraulic properties and the joint log-normal distribution for Ks and ± are given. For coarse textured and more heterogeneous landscapes, the effective hydraulic conductivity would move away from the geometric mean. In vertically heterogeneous soils, the effective hydraulic conductivity is between the geometric and the harmonic mean.

Jirka `imonek, New features of the HYDRUS-1D software are coupled water, vapor, and energy transport, support for HP1 (HYDRUS and PHREEQC), nonequilibrium flow and transport including dual permeability, potential evapotranspiration using Penman-Monteith and Hargreaves formula, water content dependence of degradation constants, and full compatibility with Vistas. The options of non-equilibrium solute transport models include uniform flow, mobile-immobile water flow, dual porosity, dual permeability, and dual permeability with mobile-immobile approach within the matrix domain. Chemical nonequilibrium transport includes the options of one-site kinetic model, two-site model (kinetic and instantaneous sorption), two-site kinetic model, dual porosity with one-site kinetic model, and dual permeability with two-site kinetic model. Furthermore, geochemical modeling will soon be possible with two HYDRUS-1D-based programs, i.e., UNSATCHEM, and PHREEQC (HP1). Results obtained in HYDRUS 2D revealed that thermal properties of the HPP needed to be taken into account, as long as thermocouples are installed midway to the heater needle, measurements are less sensitive to experimental setups, and sensor needles can be shorter. For coupled water-vapor-energy transport, larger heat pulses can be used, and flux measurements are more sensitive, i.e., smaller fluxes can be measured.

Jan Hopmans, A critical zone observatory should be established in the Sierra Nevada. One of the main objectives is to deploy wireless networks for soil moisture and energy balances. A number of wireless networks have been put out in Sequoia National Park. In this study, three networks were installed, i.e., the Isaacs link (Radio transmitter, receiver and repeater) with water mark resistance meters for soil water potential, the Decagon link with the ECH2O water content sensor and the Crossbow link combined with Isaacs Watermark sensors. The objective was to monitor soil temperature and soil water. For the Isaacs Watermarks, calibration in the lab is necessary prior to the field installation, and the temperature is a critical factor. A sensor transect was established. The Mote Crossbow Systems configuration was presented, with a base station (Omni antennae) with various nodes distributed across the landscape. The different motes interact with each other to guarantee that the signals from the sensors arrive at the base station. The system is extremely energy efficient, and includes solar panels. First results show time series of continuous water potential and temperature data recorded over a time period of approximately two months.

Navin Kumar, Soils are usually grouped according to their particle size distributions, hydraulic characteristics, and morphological descriptions or any kind of lab testing. The most commonly used and accepted system is the USDA soil classification which divides soils into 12 groups, presented in the soils textural triangle. Why are there straight lines between the classes, what is the justification for using 12 classes? The objectives of this study were to evaluate whether the USDA soil classification system provides the optimal grouping with respect to soil hydraulic characteristics, and if not, what system would provide a better grouping, and what would be the optimum number of classes with respect to soil hydraulic properties. Moreover, what would be average parameter estimates for each of these hydraulic classes? The optimum number of clusters appeared to be 12 (9-14), which is interestingly the same as the number of textural classes. However, the soil hydraulic classes differ from the textural classes. The differences occur mainly where capillary pressures play a dominant role. In this numerical study, dry bulk density was not entered as an independent parameter to derive soil hydraulic properties, but it was incorporated being a function of sand, silt, and clay content. In the future, probably sand should be divided into more fractions.

Gerard Kluitenberg, Especially in Kansas but in many regions of the U.S., low streamflows are an increasing problem in the U.S., caused by consumption of ground water by phreatophytes among other reasons. An approach that is base on daily ground water table fluctuations seems to be applicable for quantifying ground water consumption. The objective of this study was to investigate major controls in phreatophyte-induced ground water table fluctuations, to sue diurnal water table fluctuation measurements to quantify water consumption by phreatophytes, and ground water savings accomplished through control measures. Diurnal fluctuations in the riparian zone and adjacent pasture vary with respect to both amplitude and phase. The heavily vegetated riparian zone can be considered as a strip-sink with finite water use, whereas outside this strip, water use is zero. According to Townley (1955) the strip-sink is solved for, resulting in normalized amplitude of fluctuations, phase lag between ETGp and hp, and head fluctuations and phase lags relative to the position and the period (L2S/(TP). Using the solution presented here, would allow to identify the optimum location for measurements necessary for the procedure presented here. Unlike existing methods, ETG estimation is effectively estimated by the well hydrograph phase-lag information. Storativity and transmissivity will be estimated in the future. In addition, diurnal fluctuations of pressure head in the unsaturated zone will contribute to a better understanding of root water uptake causing diurnal water table fluctuations.

The chairman Thomas Harter thanked Mike Young in the name of the entire group for the excellent organization and infrastructure of this meeting as well as the interesting tour to DRIs research facility, the lysimeter station.

Brian McGlynn, The objective of this study is to link topography, geomorphic form, and landscape structure to water, energy, solute, and gas fluxes from the plot to watershed scale. A new DEM-driven flow direction algorithm was developed, because topography information steadily improves. Therefore, topographically-driven distribution of water should be evaluated. Area is chosen as a surrogate for water and flow accumulation. The Tenderfoot Creek experimental watershed was intensively instrumented with hydrological measurement facilities (27 transects with wells and piezometers, flumes, 2 Eddy covariance H20/CO2 towers, 600 m2 plot with water content and snow temperature measurements, stream and groundwater sampling facilities) across nested catchments to focus on water and carbon research. The result is that topographically driven lateral distribution of water drives upland-stream connectivity, transient connectivity drives runoff generation, a high degree of heterogeneity remains in spite of adequate time integration of space-time behavior. Watershed carbon distribution and water flux should be studied across environmental gradients in order to determine associations between soil temperature, water content, substrate, and biological controls on CO2 at the watershed scale. Results show that there is a relation between topotgraphy, topology and process patterns. Hydrological and biogeochemical processes reveal an organized heterogeneity.

Farag Botros, The objective of this study was to characterize the heterogeneity of a deep alluvial vadose zone, to model nitrate transport in the deep vadose zone, and to compare different modeling approaches to describe soil heterogeneity. The study site wasan orchard with nitrogen fertilizer application varying between 0 and 365 kg N/(ha year). For the modeling, long-term fertilizer records were available, fruit yields were recorded, and in 1997, geologic stratification was obtained from 62 continuous soil cores drilled to the water table. From 120 small cores taken from these drilled cores, 96 hydraulic property data sets were obtained to be good data. Denitrification which was not supported by field measurements, and preferential flow might explain the discrepancy of the N stoage. None of the model approaches managed to explain the small amount of stored N in the deep vadose zone. Preferential flow allowed in the two heterogeneous models did not reflect the differences in the stored N mass sufficiently. Perhaps, the 100 cores being taken were not sufficient to characterize the small scale heterogeneity. Would 3-D modeling help? Perhaps, pruning of trees caused the discrepancy in the mass balance, nitrous gas emissions might have caused nitrogen losses, and perhaps cover crop (grass) between the trees might contribute to the diverging balance.

Thomas Harter, This work directly relates to the previously presented. How good is scaling as a simple representation of a hierarchical medium, how well does it represent actual variability of K(h) and q(h), and how well does it contribute to appropriate modeling of q, h, q, c? Miller scaling was applied in this study, based on an algorithm of Clausnitzer et al. (1992). Simultaneous scaling of h and ln K and of ln h and ln K was performed. Two different data quality levels were considered, i.e., high only for 70 samples in multi-step outflow experiments and inverse modeling, and high plus regular with 27 samples form water retention curve. Transient multistep versus steady-state multistep had no significant influence on the quality. Simultaneous scaling of ln h and ln K yielded the best results. Ungrouped scaling caused results comparable to facies scaling, hence scaling across different geological layers does is ok.

Ron Amundson, The suggestion was to broaden up the soil physics group, and to include Pedology. Several past discussions and Don Nielsens presentation at the previous meeting Jan. 2007 had resulted in the strong demand, that our group should communicate with pedologists. On the other hand, some pedologists think in the same way that they needed to interact with other soil science disciplines so that the valuable pedologic description of soils compiled in soil data bases could be linked to processes occurring in soils. If both sides can get together , this would be very stimulating for the further progress of our group and the next proposal, led by Mike Young.

Initially, Ron and other soil scientists (Jan Hopmans and others) had met on the UC Davis campus with a brainstorming on how the soil science programs in California could be better integrated. An ignition for his presentation was Don Nielsens presentation from last year, and the dilemma of soil science having no reliable quantitative measures of spatially distributed soil properties across the landscape. Pedology and Soil Physics? Many students in pedology have backgrounds in physics, mathematics, ecology, etc.. Why is there not a more visible interface so far? Why is pedology not integrated better? Pedology deals with soil properties, soil physics with processes resulting in soil properties vs. processes, Soil system vs. soil, and observational vs. experimental soil science. But in fact, here exist the real opportunities for process-based, integrated soil science.

How soil physics can play a role in pedology? How can observational and experimental science be bridged? In situ geophysical processes and biology are at the cutting edge of earth sciences. Field observations can inspire new experimental approaches. Information in field trips and joint symposia, graduate education in field methods and soil physics. Opportunities for process-based integrated soil science: NSF programs (Low temperature geochemistry and geomicrobiology, critical zone observatories)NASA planetary geology, and
Transformative efforts in SSSA.

The discussion following up Ron Amundsons presentation was directed towards a vision for future activities of the W1188 group. The discussion of the new project proposal and the next meeting in 2009 were very closely related. Ron Amundsons presentation was received by the group as a great success and igniting contribution to the question what the role soil physics can play in related disciplines and vice versa, and how soil physicists, pedologists and others can start interacting with each other. There is a small group of soil pedologists who began looking at soil processes across landscapes.

The next meeting will be held over a 3-day period with beginning on Monday, January 5, 09 at noon time, and the end on Thursday noon, January 8, 09. These 3 days will be divided into two days with presentations, and one day of brainstorming sessions including presentations of invited speakers. The format of sessions will probably be a hybrid type, including think tanks. Sufficient discussion time needs to be provided for invited speakers to discuss and comment our proposal. First suggestions on names for invited speakers were: Ron Amundson, Marc Parlange, Henry Lin, Jon Chorover &(could not catch all names in the short time period and might have missed one or two. Please add any eventually missing ones).

The next steps in writing the new proposal for the time period 2009-2014:
The new proposal will have to be submitted to the Board of Western Directors in January 2009. The core committee will write a first draft of the proposal during the next 2 to 3 months, circulate it to the group, include comments from the group, and then have a first version of the proposal ready in summer of 2008. At this point it needs clarification whether this first version of the proposal needs further approval.

The group writing the proposal will be: Mike Young (head), Scott Jones, John Neiber, Markus Tuller, Marcel Schaap, and Ole Wendroth. The vision documented in this new proposal will have strong impact on the focus and the format of the next meeting in January 2009. The questions of the relevance of soil physics and whether or not to go for esoteric soil physics were discussed. During the discussion, focus on either one or several objectives was debated with no strong opinion on particular objectives but with emphasis on broadening the focus of the group and opening it to related disciplines while not loosing the identity of a soil physics group. The link of soil physics to other disciplines will be a driving force for the coming meeting and project period.

Accomplishments

OBJECTIVE 1: To develop and improved understanding of the fundamental soil physical properties and processes governing mass and energy transport, and the biogeochemical interactions these mediate. Interrelated, biotic and abiotic processes were examined at four sites in the northern Mojave Desert by University of Nevada. Infiltration through Av horizons evolves from a matrix-dominated process on the younger soils to a preferential flow-dominated process on older surfaces. USDA Salinitiy Lab worked on models for colloid and microorganism transport and retention in porous media. Experiments and models demonstrated that much greater retention is possible in the smallest regions of the pore space that are associated with lower flow rates. Washington State University showed that transient flow mobilized more colloids than steady-state flow. Mechanical straining of colloids was partly responsible for the smaller colloid mobilization in the fine than in the coarse sands. Larger flow rates led to increased colloid mobilization and europium elution. Wyoming developed a new model based on a noniterative solution of the Richards equation. It calculates soil water flow heat transport, and soil water freezing for grid cells at the watershed level. The fate and transport of 17b-estradiol (E2) and testosterone (T) in soils were investigated by North Dakota. Soil water content and organic matter were significant in explaining hormone distributions in the soil. Soil humic substances can immobilize the majority of hormones. UC Riverside initiated an investigation on the fate of pharmaceutical products applied to turfgrass with reclaimed wastewater. A new equilibrium equation was derived to predict the ion distribution between the exchanger and solution phases. Scientists from the Batelle Pacific Northwest Division compared different model approaches to the saturation-dependent anisotropy. The tensorial connectivity-tortuosity (TCT) model had the smallest average error. Iowa scientists tested diffusion-based coupled soil heat and water transfer theory. Work is planned on coupled water and heat transport under transient conditions. Near-surface soil heat fluxes account for as much as 80% of net radiation as the evaporation zone proceeds below the surface. A lattice-Boltzmann model approach was chosen by Tucson to simulate microscopic liquid-air interphase processes. Moreover, dehydration studies on initiation and evolution of surface crack networks in active clay soils were performed in conjunction with X-Ray Computed Tomography (CT) observations. Mixing bentonite with sand- or silt-like materials reduces susceptibility to formation of desiccation cracks. UC Davis combined field experiments and numerical simulations to study effects of various irrigation and fertigation systems. Soil salinity measurements showed considerable leaching around drip lines due to spatially-varying soil wetting patterns that occur under drip irrigation. Utah State tested water retention and gas diffusion in 3 different particle-sized media. Their focus is on maintaining plant health in the absence of gravity. Highly localized non-uniform water contents may lead to potential problems with oxygen supply to plant roots within zones of higher water content. Oregon proposed a mechanism for enhanced evaporation consisting of thermally driven convective venting of the fractures occurring at night. Salt is depositing in the smaller pores and surface precipitation occurs over the area of small pores. Thus, the surface patchiness is associated with the location of smaller pores. California State University characterized groundwater flow in the fractured granite aquifers in the foothill areas of western Sierra Nevada, Madera County of California. Variations in the results suggested that both the flow patterns and the model parameters were scale-dependent and related to heterogeneity within the aquifer. Montana works on the critical drivers that govern catchment water, carbon, and gas behavior and movement and how they are integrated by larger-scale measurements. This research will address the landscape controls on riparian buffering of the quantity, quality, and timing of water delivered from alpine headwater watersheds. OBJECTIVE 2: To develop and evaluate instrumentation and methods of analysis for characterizing mass and energy transport in soils at different scales Nevada has been examining Raman Spectra Fiber Optic Distributed Temperature Sensing. They analyzed dual-probe heat-pulse (DPHP) data for estimating volumetric water content of near-surface materials. The variability of ET rate for moderately dense desert shrubland contributed to over 78% of the variance in total ground-water discharge. Washington State University determined the effective vapor diffusion coefficients and the diffusive resistances through wheat residue layers. They also evaluated the effect of wildfire on soil water repellency. Remotely sensed hyperspectral imagery was collected to map post-wildfire ground cover and soil condition. An electric circuit model was developed by Wyoming for the Hydra probe sensor measuring real permittivity, imaginary permittivity and temperature. The real permittivity can be converted into soil water content by using a soil-specific calibration. USDA-ARS, Minnesota, contribute to a better understanding of the surface energy balance by measuring apparent thermal conductivity (la) and apparent volumetric heat capacity (Ca) which permits accurate monitoring of soil heat flux under freezing and thawing conditions. UC Riverside found that humic substances and dissolved organic matter reduce the surface tension at the liquid-air interface. Capillary pressure is lowered at the same water content in soils containing DOM. HYDRUS now considers the concentration dependence of surface tension and the contact angle dependence of capillary pressure. Pacific Northwest Division performed experiments to study the behavior of radioactive contaminants that escape from corroded tanks. Experimental installations included continuous soil water content monitoring devices. Iowa state examined the effect of low connectivity of intra-granular pores on diffusion and retardation of an inert conservative tracer. Most of the study of systems is completed, starting from equilibrium, and some follow-up studies on dynamic systems have started. UC Davis used the multi-functional heat pulse probe (MFHPP) for measuring coupled water, heat, and solute transport simultaneously. Neutron computed tomography was applied successfully in a single root water uptake experiment showing spatially-variable soil water content gradients in the rhizosphere. University of Arizona conducted a preliminary image binarization study suitable for CT data. The various methods considerable deviate from each other, some of them underestimating and some of them overestimating measured porosities. Utah State University evaluated the Penta-needle Heat Pulse Probe (PHPP): It can provide good estimation of 2-D soil water fluxes. Evaluation of self filling tensiometers showed that they were not suitable for forest soil application under freeze/thaw conditions. California State University contributed to a better understanding of the San Joaquin River regional hydrology. Stable isotope analysis in different groundwater zones revealed that groundwater collected near to the river showed more depletion than samples taken form the river. Montana developed a software to generate synthetic Time Domain Reflectometry (TDR) waveforms for evaluating probes, and predicting travel time analysis. Montana is evaluating flood generation, streamwater residence times, sources and pathways of runoff, riparian buffering of hillslope runoff, water quality dynamics, and the heterogeneity of CO2 generation and flux across watersheds. Kansas State University contributed to the volumetric characterization of the spatial sensitivity of the DPHP method. Moreover, diurnal water-table fluctuations observed in shallow wells in vegetated riparian zones are a diagnostic indicator of groundwater consumption by evapotranspiration (ETG). OBJECTIVE 3: To develop and evaluate scale-appropriate methodologies for the management of soil and water resources Nevada contributed to the restoration of disturbed lands in the Mojave Desert; particularly re-vegetation of military lands. The optimal macroscopic hydraulic conductivities for both horizontally and vertically heterogeneous soils depended on the pressure head conditions at the land surface. USDA Salinity Lab implemented a nutrient management plan using cyclic and blending irrigation strategies for dairy lagoon water application (interagency project with EPA). Contaminant concentrations (salts, heavy metals, nutrients, hormones, and antibiotics) were quantified in various lagoon water samples. Washington State used DEMs to calculate topographic and hydrologic parameters that served as inputs to WEPP. The model results of sediment yields and runoffs were compared with field observations, and showed that different resolutions cause considerable differences in erosion modeling results. Wyoming scientists initiated a study on the leaching potential of trace elements like Arsenic and Selenium from Coalbed Methane water disposal ponds. Coalbed Methane extraction involves pumping from coal seams to reduce the water pressure and release the gas. The marginal quality water is generally released into streams and surface ponds. Three different methods for delineating nitrogen management zones were tested by North Dakota. Even though this field site had significant variation in soil ECa, topography, and soil color, zone management seemed to result in uniformity of yield across the site. UC Riverside investigated metal uptake of corn in biosolid-treated sand media. The effect of particle-size distribution on uptake of Cu and Ni was less pronounced than that on Cd and Zn, while the uptake of Cr and Pb were dominated by their chemical speciation of the biosolids. Pacific Northwest Division investigated the saturation-dependent anisotropy of unsaturated hydraulic conductivity. The model showed that the anisotropic coefficient of any one of the fluids depends only on the saturation of the fluid being considered but not on saturation of other fluids. Iowa State estimated the distribution and extent of drainage across the U.S. Long-term simulations suggest that at least half of the N loss reduction goal could be met by reducing N application rates. Model simulations demonstrated how to reduce losses of NO3-N in subsurface drainage. No-till practice significantly increased SOC storage and reduced nitrateN leaching rate, but slightly decreased crop yield and increased N2O emissions. Arizona integrated easily obtainable data with hydraulic property data to generate heterogeneous soil hydraulic parameters for a field injection test and 3-D modeling of a contaminant plume. The parameter estimates were used to simulate a field injection experiment. Good agreement was obtained between the simulated and observed moisture contents. UC Davis predicted the water-content dependent soil moisture variability by stochastic analysis of the unsaturated Brooks-Corey flow in heterogeneous soils for eleven textural classes. The b parameter, which describes the pore-size distribution of soils, controls the maximum value of the soil moisture standard deviation. Utah State University developed a methodology to describe the process of obtaining soil properties from maps of electrical conductivity. Correlating vegetation maps with the EMI map to link hydrological properties with vegetation community structure is further pursued. UC Riverside coupled a geochemical modeling code with HYDRUS to simulate a broad range of low-temperature biogeochemical reactions in water, soil and ground water systems. A new module CW2D for biochemical transformation and degradation processes in subsurface flow constructed wetlands has been released. A model that can consider transport of solutes facilitated by the presence of colloids has also been developed. Numerical models were applied to simulate transport of various contaminants. A major upgrade of HYDRUS-2D/MESHGEN-2D software package called HYDRUS (2D/3D) was released. California State University applied remote sensing information and the DEM for estimating spatio-temporal snow depth behavior for the Upper San Joaquin River watershed above Friant Dam. Montana found that a vegetated cap system designed to prevent leaching of meteoric water failed to function as desired during both years of available data. A method was developed to examine the impact of geographic location and spatial distribution of land use/land cover change on the spatial, seasonal, and temporal patterns of streamwater nitrogen (N). Upon KBr tracer application, Kentucky identified spatial correlation lengths for anion concentration of approximately 1 m. At the landscape scale, surface soil water content is spatially closely associated with profile water storage. Relations between soil texture and surface soil moisture strongly vary with spatial scale, support, and distance. Texas A&M adopted a multi-facet approach to field soil hydraulic property characterization including: a bottom-up approach, a top-down approach, and an artificial neural network approach. UC Davis initiated an extensive characterization and geostatistical analysis of the geology, hydraulic properties, and nitrogen distribution in a 16 m deep vadose zone across a nectarine orchard. Unsaturated flow and transport simulations for both types of heterogeneity representations of the vadose zone were implemented with HYDRUS. The flow velocity distribution in the MPHR-based simulations is more variable than in the SFA-based simulations.

Publications

Abdu, H., D.A. Robinson and S. B. Jones. 2007. Comparing bulk soil electrical conductivity determination using the DUALEM 1-S and EM-38DD EMI instruments. Soil Sci. Soc. Am. J. 71:189-196. Baker, J.M., T.E. Ochsner, R.T. Venterea, and T.J. Griffis. 2007. Tillage and carbon sequestration--What do we really know? Agr. Ecosyst. Environ. 118:1-5. Berli, M., A. Carminati, T.A. Ghezzehei, and D. Or. 2007a. Unsaturated hydraulic conductivity of aggregated soils under compression. Water Resour. Res. (Special Issue). In revision. Berli, M., T. Caldwell, E.V. McDonald, and D.A. Gilewitch. 2007b. Modeling desert pavement deterioration due to heavy vehicle traffic. J. Terramechanics. In review. Børgesen, C.D., B.V. Iversen, O.H. Jacobsen, M.G. Schaap. 2007. Pedotransfer functions estimating soil hydraulic properties using different soil parameters. Hydrol. Proc. In press. Bradford, S. A., and N. Toride. 2007. A stochastic model for colloid transport and deposition. J. Environ. Qual. 36: 1346-1356. Bradford, S. A., and S. Torkzaban. 2008. Colloid transport and retention in unsaturated porous media: A review of interface, collector, and pore scale processes and models. Vadose Zone J. In press. Bradford, S. A., E. Segal, W. Zheng, Q. Wang, and S. R. Hutchins. 2008. Reuse of CAFO waterwater on agricultural lands: Potential environmental contaminants, transport pathways, and treatments. J. Environ. Qual. In press. Bradford, S. A., S. Torkzaban, and S. L. Walker. 2007. Coupling of physical and chemical mechanisms of colloid straining in saturated porous media. Water Res. 41: 3012-3024. Butler, J. J., Jr., G. J. Kluitenberg, D. O. Whittemore, S. P. Loheide, II, W. Jin, M. A. Billinger, and X. Zhan. 2007. A field investigation of phreatophyte-induced fluctuations in the water table. Water Resour. Res. 43:W02404 doi:10.1029/2005WR004627. Caldwell, T.G., E.V. McDonald, and M.H. Young. 2007b. The seedbed microclimate and active revegetation of disturbed lands in the Mojave Desert. J. Arid Environ. In revision Caldwell, T.G., E.V. McDonald, S.N. Bacon, and G. Stullenbarger. 2007a. The performance and sustainability of vehicle dust courses for military testing. J. Terramechanics. In press. Casey, F.X.M., P. Odour, H. Hakk, and G.L. Larsen. 2007. Transport of 17ß-Estradiol and Testosterone in a field lysimeter. In Annual Meetings Abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Chen, W., A.C. Chang, and L. Wu. 2007. Assessing long-term environmental risks of trace elements in Phosphate fertilizers. Ecotoxicol. Environ. Safety 67:48-58. Chen, W., A.C. Chang, L. Wu, L. Li, S.-I. Kwon, and A.L. Page. 2007. Probability distribution of Cd partitioning coefficients of cropland soils. Soil Sci. 172:132-140. Chen, W., L. Li, A.C. Chang, L. Wu, S.-I. Kwon, and R. Bottoms. 2007. Modeling the uptake kinetics of cadmium by field-grown lettuce. Environ. Pollut. doi:10.1016/j.envpol.2007.05.004. Chief, K., T.P.A. Ferré, and A. C. Hinnell. 2007b. The effects of anisotropy on in situ air permeability measurements. Vadose Zone J. Accepted. Chief, K., T.P.A. Ferré, and B. Nijssen. 2006. Field testing of a soil corer air permeameter (SCAP) in desert soils. Vadose Zone J. 5:1257-1263. Chief, K., T.P.A. Ferré, and B. Nijssen. 2007a. Predicting saturated hydraulic conductivity from air permeability in unburned and burned soils. Soil Sci. Soc. Am. J. Accepted. Conrad, M. E., D. J. DePaolo, K. Maher, G. W. Gee, and A. L. Ward. 2007. Field evidence for strong chemical separation of contaminants in the Hanford vadose zone. Vadose Zone J. 6:1031-1041. Corwin, D. L., J. D. Rhoades, and J. `imonek. 2007. Leaching requirement for soil salinity control: Steady-state vs. transient-state models. Agric. Water Manage. 90:165-180. Covino, T.P., and B.L. McGlynn. 2007. Stream gains and losses across a mountain-to-valley transition: Impacts on watershed hydrology and stream water chemistry. Water Resour. Res. 43, W10431, doi:10.1029/2006WR005544. Das, N.N., and B.P. Mohanty. 2007. Dynamics of PSR-based soil moisture in a large agricultural landscape during SMEX02: A wavelet approach wavelet analyses. Rem. Sens. Environ. Das, N.N., B.P. Mohanty, M.H. Cosh, and T.J. Jackson. 2007. Modeling and assimilation of root zone soil moisture using remote sensing observations in Walnut Gulch watershed during SMEX04. Rem. Sens. Environ. Derby, N.E., F.X.M. Casey, and D.W. Franzen. 2007. Comparison of Nitrogen management zone delineation methods for Corn grain yield. Agron J. 10.2134/agronj2006.0027 99:405-414. Devitt, D.A., M.H. Young, M. Baghzouz, and B.M. Bird. 2007. Surface temperature, heat loading, and spectral reflectance of artificial turfgrass. J. Turfgrass Res. In press. Dousset, S., M. Thevenot, V. Pot, J. `imunek, and F. Andreux. 2007. Evaluating equilibrium and non-equilibrium transport of bromide and isoproturon in disturbed and undisturbed soil columns. J. Contam. Hydrol. 94, 261-276. Doyle, T.E., D.A. Robinson, S.B. Jones, K.H. Warnick and B.L. Carruth. 2007. Modeling the permittivity of two-phase media containing monodisperse spheres: Effects of microstructure and multiple scattering. Physical Review B 76 (5), 054203. Dragila, M. I. 2007. Improved characterization and quantification of flow and transport processes in soils. W-1188 Regional Project Annual Report for 2007. Eggers C.G., M. Berli, M.L. Accorsi, D. Or. 2007. Permeability of deformable soft aggregated earth materials: From single pore to sample cross section. Water Resour. Res. 43. Art. No. W08424. Ewing, R. P., and R. Horton. 2007. Thermal conductivity of a cubic lattice of spheres with capillary bridges. J. Phys. D Appl. Phys. 40: 4959-4965. Fan, Z. 2007. Measuring and modeling fate and transport of natural hormones in soil-water systems. Research Dissertation, North Dakota State University, Fargo. Fan, Z.S., F.X.M. Casey, H. Hakk, and G.L. Larsen. 2007a. Persistence and fate of 17²-estradiol and testosterone in agricultural soils. Chemosphere 67:886-895. Fan, Z.S., F.X.M. Casey, H. Hakk, and G.L. Larsen. 2007b. Discerning and modeling the fate and transport of testosterone in undisturbed soil. J. Environ. Qual. 36:864-873. Farahbakhshazad, N., D.L. Dinnes, C. Li, D.B. Jaynes, and W. Salas. 2008. Modeling biogeochemical impacts of alternative management practices for a row-crop field in Iowa. Agricult. Ecosys. Environ. 123:3048. Flury, M. and J. Mon. 2007. Dyes as hydrological tracers. In: The Encyclopedia of Water, edited by J. H. Lehr, J. Keeley, and J. Lehr, John Wiley, New York. In press. Flury, M., and H. Qiu. 2007. Modeling colloid-facilitated contaminant transport in the vadose zone. Vadose Zone J. In press. Flynn, E.S., C.T. Dougherty, and O. Wendroth. 2007. Assessment of Grassland Condition with the Normalized Difference Vegetation Index. Agron. J. (accepted, in press). Gargiulo, G., S. A. Bradford, J. Simunek, P. Ustohal, H. Vereecken, and E. Klumpp. 2007. Bacteria transport and deposition under unsaturated conditions: the role of the matrix grain size and the bacteria surface protein. J. Contam. Hydrol. 92: 255-273. Gargiulo, G., S. A. Bradford, J. `imonek, P. Ustohal, H. Vereecken, and E. Klumpp. 2007. Transport and deposition of metabolically active and stationary phase Deinococcus Radiodurans in unsaturated porous media. Environ. Sci. Technol. 41:1265-1271. Gaur, A., D. B. Jaynes, R. Horton, and T. E. Ochsner. 2007. Surface and subsurface solute transport properties at row and inter-row positions. Soil Sci. 172:419-431. Gee, G. W., M. Oostrom, M. D. Freshley, M. L. Rockhold, and J. M. Zachara. 2007. Hanford site vadose zone studies: An overview. Vadose Zone J. 6:899-905. Hanson, B. R., J. `imonek, and J. W. Hopmans. 2008. Leaching with subsurface drip irrigation under saline, shallow ground water conditions. Vadose Zone J. In press. Hanson, B.R., J.W. Hopmans, and J. Simunek. 2007. Leaching with subsurface drip irrigation under saline, shallow groundwater conditions. Vadose Zone J. In press. Haruta, S., W. Chen, J. Gan, J. Simunek, A. Chang, and L. Wu. 2007. Leaching risk of N-nitrosodimethylamine (NDMA) in soil receiving reclaimed wastewater. Heinse, R., S.B. Jones, S. Steinberg, M. Tuller, and D. Or. 2007. Effects of variable gravity on liquid behavior in particulate porous media: Measurements and modeling. Vadose Zone J. In press. Heinse, R., S.B. Jones, S. Steinberg, M. Tuller, and D. Or. 2007. Uncovering the challenges of watering plants in space. Crops, Soils, Agronomy (CSA) News. 52(12):1-4. Heinse, R., S.B. Jones, S.L. Steinberg, M. Tuller, and D. Or, 2007. Measurements and modeling of variable gravity effects on water distribution and flow in unsaturated porous media. Vadose Zone J. 6:713-724, doi:10.2136/vzj2006.0105. Heitman, J.L., A. Gaur, R. Horton, D.B. Jaynes, and T.C. Kaspar. 2007. Field measurement of soil surface chemical transport properties for comparison of management zones. Soil Sci. Soc. Am. J. 71:529-536. Heitman, J.L., R. Horton, T. Ren, and T.E. Ochsner. 2007. An improved approach for measurement of coupled heat and water transfer in soil cells. Soil Sci. Soc. Am. J. 71:872-880. 10.2136/sssaj2006.0327. Heitman, J.L., R. Horton, T.J. Sauer, and T.M. DeSutter. 2008. Sensible heat observations reveal soil-water evaporation dynamics. J. Hydromet. In press. Hopmans, J.W. 2006. Plant water and nutrient uptake in soil-root systems. 5.1. Rhizosphere Models. In Handbook of Methods used in rhizosphere research. COST. Swiss Federal Research Institute WSL, Birmensdorf, pg. 495-96. Hopmans, J.W. 2007. A plea to reform soil science education. Commentary. Soil Sci. Soc. Am. J. 71:639-640. Huang, H., D.T. Thorne, M.G. Schaap, and M.C. Sukop. 2007. A priori determination of contact angles in Shan-and- Chen-type multi-component multiphase lattice Boltzmann models. Phys Rev E., 76, 066701 Hyatt, J., O. Wendroth, D.B. Egli, and D.M. TeKrony. 2007. Soil Compaction and Soybean Seedling Emergence. Crop Sci. 47:24952503. Istok, J.D., M.M. Park, A.D. Peacock, M. Oostrom, and T.W. Wietsma. 2007. An experimental investigation of nitrogen gas produced during denitrification. Ground Water 45:461-467. Jacques, D., J. `imonek, D. Mallants, and M. Th. van Genuchten. 2008. Modeling coupled hydrological and chemical processes in the vadose zone: a case study on long term uranium migration following mineral P-fertilization. Vadose Zone J. Special Issue Vadose Zone Modeling. In press. Jana, R., B.P. Mohanty, and E.P. Springer. 2007. Multi-scale pedo-transfer functions for soil water retention. Vadose Zone J. 6:868-878. Jaynes, D.B., D.C. Olk, T.S. Colvin, T.C. Kaspar, and D.L. Karlen. 2007. Response to Comments on Need for a soil-based approach in managing nitrogen fertilizers for profitable Corn production and soil organic nitrogen enrichment following Soybean in an Iowa Corn-Soybean rotation. Soil Sci. Soc. Am. J. 71:255. Jones, S.B., and K. Shenai. 2007. Subsurface measurement needs for ecological, hydrological and agricultural applications. Proc. 50th IEEE Int. Midwest Symp. on Circuits and Systems (MWSCAS). August 5-7, Montreal, CA, Invited. Kaspar, T.C., D.B. Jaynes, T.B. Parkin, and T.B. Moorman. 2007. Rye cover crop and gamagrass strip effects on NO3 concentration and load in tile drainage. J. Environ. Qual. 36:15031511. Khaleel, R., M. D. White, M. Oostrom, M. I. Wood, F. M. Mann, and J. G. Kristofzski. 2007. Impact assessment of existing vadose zone contamination at the Hanford Site SX tank farm. Vadose Zone J. 6:935-945. Kim, S.B., H.S. On, D.J. Kim, W. A. Jury, and Z. Wang. 2007. Determination of bromacil transport as a function of water and carbon content in soils. J. Environ. Sci. Health Part B 42:529537. Kluitenberg, G.J., T.E. Ochsner, and R. Horton. 2007. Improved analysis of heat pulse signals for soil water flux determination. Soil Sci. Soc. Am. J. 71:53-55. 10.2136/sssaj2006.0073N. Knight, J.H., W. Jin, and G. J. Kluitenberg. 2007. Sensitivity of the dual-probe heat-pulse method to spatial variations in heat capacity and water content. Vadose Zone J. 6:746-758. Kodeaová, R., M. Koárek, V. Kodea, J. `imonek, and J. Kozák. 2008. Impact of soil micromorphological features on water flow and herbicide transport in soils. Vadose Zone J. Special Issue Vadose Zone Modeling. In press. Last, G. V., C. J. Murray, D. A. Bush, E. C. Sullivan, M. L. Rockhold, R. D. Mackley, and B. N. Bjornstad. 2007. Standardization of borehole data to support vadose zone flow and transport modeling. Vadose Zone J. 6:906-912. Lazarovitch, N., A. Ben-Gal, J. `imonek, and U. Shani. 2007. Uniqueness of soil hydraulic parameters determined by a combined Wooding inverse approach. Soil Sci. Soc. Am. J. 71, doi:10.2136/sssaj2005.0420, 860-865. Lazarovitch, N., A. W. Warrick, A. Furman, and J. `imonek. 2007. Subsurface water distribution from drip irrigation described by moment analyses, Vadose Zone J. 6:116-123. Lebron, I., M.D. Madsen, D.G. Chandler, D.A. Robinson, O. Wendroth, and J. Belnap. 2007. Ecohydrological controls on soil moisture and hydraulic conductivity within Pinyon-Juniper Woodland. Water Resour. Res. 43, W08422, doi:10.1029/2006WR005398. Lee, K. H., N. Zhang, and G. Kluitenberg. 2007. A frequency-response permittivity sensor for simultaneous measurement of multiple soil properties: Part I. The frequency-response method. Trans. ASABE 50:2315-2326. Lewis, S.A., P.R. Robichaud, B.E. Frazier, J.Q. Wu. and D.W. Laes. 2007. Using hyperspectral imagery to predict post-wildfire soil water repellency. Geomorphol. In press. Li, H., and L. Wu. 2007. A generalized linear equation for non-linear diffusion in external fields and non-ideal systems. New J. Physics 9:357. Li, H., and L. Wu. 2007. A new approach to estimate ion distribution between the exchanger phase and solution phase. Soil Sci. Soc. Am. J. 71:1694-1698. Li, H., H. Li, W.-J. Shi, and Z. Wang. 2007. Research of finger flow in porous media - Summary and perspective. Soils. Liu, G., B. Li, T. Ren, and R. Horton. 2007. Analytical solution of heat pulse method in a parallelepiped sample space. Soil Sci. Soc. Am. J. 71: 1607-1619. Loescher, H.W., J. Jacobs, O. Wendroth, D.A. Robinson, G.S. Poulos, K. McGuire, P. Reed, B.P. Mohanty, J.B. Shanley, W. Krajewski. 2007. Enhancing water cycle measurements for future hydrologic research. Bulletin of American Meteorological Society (BAMS) 88:669-676. DOI:10.1175/BAMS-88-5-669. Lu, S., T. Ren, Y. Gong, and R. Horton. 2007. An improved model for predicting room temperature soil thermal conductivity versus water content. Soil Sci. Soc. Am. J. 71:8-14. Ma, L., R.W. Malone, P. Heilman, D.B. Jaynes, L.R. Ahuja, S.A. Saseendran, R.S. Kanwar, and J.C. Ascough II. 2007. RZWQM simulated effects of crop rotation, tillage, and controlled drainage on crop yield and nitrate-N loss in drain flow. Geoderma 140:260271. Meadows, D.G., M.H. Young, E.V. McDonald. 2007. Influence of surface age on infiltration mechanisms of desert pavements, Mojave Desert. Catena 72:169-178. Moffett, K., S. Tyler, T. Torgersen, M. Menon, J. Selker and S. Gorelick. 2007. Distributed temperature sensing of thermal trends and anomalies in the bed of an intertidal salt marsh and channel: The tidal thermal blanket effect. Environ. Science Tech. In press. Mohanty, B. P., and J. Zhu. 2007. Effective hydraulic parameters in horizontally and vertically heterogeneous soils for steady-state landatmosphere interaction. J. Hydrometeorol. 8: 715-729. Murray, C. J., A. L. Ward, and J. L. Wilson. 2007. Influence of clastic dikes on vertical migration of contaminants at the Hanford Site. Vadose Zone J. 6:959-970. Nachshon, U., N. Weisbrod, M.I. Dragila. 2007. Quantifying air convection through surface-exposed fractures. Vadose Zone J. Submitted. Ochsner, T.E., T.J. Sauer, and R. Horton. 2007. Soil heat storage measurements in energy balance studies. Agron. J. 99:311-319. 10.2134/agronj2005.0103S. Oostrom, M., J.H. Dane, and T.W. Wietsma. 2007. A review of multidimensional, multifluid intermediate-scale experiments: Flow behavior, saturation imaging, and tracer detection and quantification . Vadose Zone J. 6:610-637. doi:10.2136/vzj2006.0178 Oostrom, M., M. L. Rockhold, P. D. Thorne, M. J. Truex, G. V. Last, and V. J. Rohay. 2007. Carbon Tetrachloride flow and transport in the subsurface of the 216-Z-9 trench at the Hanford Site. Vadose Zone J. 6:971-984. Oostrom, M., M.J. Truex, P.D. Thorne, and T.W. Wietsma. 2007. Three-dimensional multifluid flow and transport at the Brooklawn site near Baton Rouge, LA: A Case Study. Soil Sediment Contamin. 16:109-141. Oostrom, M., T.W. Wietsma, M.A. Covert, and V.R. Vermeul. 2007. Zero-valent iron emplacement in permeable porous media using polymer additions. Ground Water Monit. Remed. 27:122-130. Or, D., B.F. Smets, J.M. Wraith, A. Duchesne, and S.P. Friedman. 2007. Physical constraints affecting bacterial habitats and activity in unsaturated porous media - a review. Adv. Water Resour. Special Issue: Biological processes in porous media: from the pore scale to the field. 30:1505-1527. Pan, F., M. Ye, Y.-S. Wu, B.X. Hu, J. Zhu, and Z. Yu. 2007. Uncertainty assessment of unsaturated flow and tracer transport in heterogeneous fractured media. J. Contam. Hydrol. In revision. Pang, L., M. McLeod, J. Aislabie, J. `imonek, M. Close, and R. Hector. 2008. Modeling transport of fecal coliforms and Salmonella bacteriophage in ten undisturbed New Zealand soils under dairy shed effluent irrigation. Vadose Zone J. In press. Riveros-Iregui, D.A., R.E. Emanuel, D.J. Muth, B.L. McGlynn, H.E. Epstein, D.L. Welsch, V.J. Pacific, and J.M. Wraith. 2007. Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content. Geophys. Res. Lett. 34. L17404. doi:10.1029/2007GL030938. Robinson, D.A., S.B. Jones, T. Doyle, J.M. Blonquist, H. Abdu, V. Urdanoz, R. Aragues. 2007. Hydrological processes and properties of soil using electromagnetic measurement. Proc. Int. Conf. Microwaves Optoelectronics 2007 (ICMO), December 17-20, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, India. Saito, H., J. `imonek, J. W. Hopmans, and A. Tuli. 2007. Numerical evaluation of the heat pulse probe for simultaneous estimation of water fluxes and soil hydraulic and thermal properties. Water Resour. Res. 43: W07408, doi:10.1029/2006WR005320. Saleh, A., E. Osei, D.B. Jaynes, B. Du, and J.G Arnold. 2007. Economic and environmental impacts of LSNT and cover crops for nitrate-nitrogen reduction in Walnut Creek watershed, Iowa, using FEM and enhanced SWAT models. Trans. ASABE 50: 1251-1259. Sansoulet, J., Y.-M. Cabidoche, P. Cattan, S. Ruy, and J. `imonek. 2008. Spatially distributed water fluxes in an Andisol under banana plants: experiments and 3D modelling. Vadose Zone J. Special issue Vadose Zone Modeling. In press. Sauer, T.J., T.E. Ochsner, and R. Horton. 2007. Soil heat flux plates: Heat flow distortion and thermal contact resistance. Agron. J. 99:304-310. 10.2134/agronj2005.0038s. Schaap, M.G, M.L. Porter, B.S.B. Christensen, and D. Wildenschild, 2007a. Comparison of pressure-saturation characteristics derived from computed tomography and lattice Boltzmann simulations. Water Resour. Res. 43, W12S06, doi:10.1029/2006WR005730 Segal., E., S. A. Bradford, P. Shouse, N. Lazarovitch, and D. Corwin. 2008. Integration of hard and soft data to characterize field-scale hydraulic properties for flow and transport studies. Vadose Zone J. In press. Seibert J., and B.L. McGlynn. 2007. A new triangular multiple flow-direction algorithm for computing upslope areas from gridded digital elevation models. Water Resour. Res. 43, W04501, doi:10.1029/2006WR005128. Shafer, D.S., M.H. Young, S.F. Zitzer, T.G. Caldwell, E.V. McDonald. 2007. Impacts of interrelated biotic and abiotic processes during the past 125,000 years of landscape evolution in the northern Mojave Desert, Nevada, U.S.A. J. Arid Environ. 69:633-657. `imonek, J. 2007. Models for soil pollution risk assessment, Proc. of NATO Advanced Research Workshop Air, Water and Soil Quality Modelling for Risk and Impact Assessment, Eds. A. Ebel and T. Davitashvili, NATO Security through Science Series C: Environmental Security, Springer, ISBN-10 1-4020-5876-4 (PB), 221-233. `imonek, J., and M. Th. van Genuchten. 2008. Modeling nonequilibrium flow and transport with HYDRUS. Vadose Zone J. Special Issue Vadose Zone Modeling. In press. `imonek, J., M. Th. van Genuchten, and M. `ejna. 2007. Modeling subsurface water flow and solute transport with HYDRUS and related numerical software packages, In: Garcia-Navarro & Playán (eds.), Numerical Modelling of Hydrodynamics for Water Resources, An International Workshop, Centro Politecnico Superior, University of Zaragoza Spain, June 18-21 2007. Taylor & Francis Group, London, ISBN 978-0-415-44056-1, 95-114. `imonek, J., M. Th. van Genuchten, and M. `ejna. 2008. Development and applications of the HYDRUS and STANMOD software packages, and related codes. Vadose Zone J. Special Issue Vadose Zone Modeling. In press. Smucker, A., and J.W. Hopmans. 2007. Soil biophysics. doi:10.2136/vzj2007.0057. Vadose Zone J. 6:267-268. Srivastava, P., K. W. Migliaccio, and J. `imunek. 2007. Centennial manuscript: Terrestrial models for simulating water quality at point, field, and watershed scales, Trans. ASAE 50:1683-1693. Suarez, F., J. Bachmann, J.F. Munoz, C. Ortiz, S. Tyler, C. Alister and M. Kogan. 2007. Transport of Simazine in unsaturated sandy soils and prediction of leaching under field conditions. J. Contam. Hydrol. 94(3/4):166-177. Thornton, E. C., L. Zhong, M. Oostrom, and B. Deng. 2007. Experimental and theoretical assessment of the lifetime of a gaseous-reduced vadose zone permeable reactive barrier. Vadose Zone J. 6:1050-1056. Thorp, K.R., R.W. Malone, and D.B. Jaynes. 2007. Simulating long-term effects of nitrogen fertilizer application rates on corn yield and nitrogen dynamics. Trans. ASABE 50:1287-1303. Torkzaban, S., S. A. Bradford, and S. L. Walker. 2007. Resolving the coupled effects of hydrodynamics and DLVO forces on colloid attachment to porous media. Langmuir 23: 9652-9660. Torkzaban, S., S. A. Bradford, M. Th. van Genuchten, and S. L. Walker. 2007. Colloid transport in unsaturated porous media: The role of water content and ionic strength on particle straining. J. Contam. Hydrol. In press. Torkzaban, S., S. S. Tazehkand, S. L. Walker, and S. A. Bradford. 2008. Transport and fate of bacteria in porous media: Coupled effects of chemical conditions and pore space geometry. Water Resour. Res. In press. Tumlinson, L.G., J.W. Hopmans, Liu, and W.K. Silk. 2008. Thermal neutron computed tomography of soil water and plant roots. Soil Sci. Soc. Am. J. In press. Twarakavi, N. K. C., H. Saito, and J. `imonek. 2008. A new approach to estimate soil hydraulic parameters using only soil water retention data. Soil Sci. Soc. Am. J. In press. Twarakavi, N. K. C., J. `imonek, and H. S. Seo. 2008. Evaluating interactions between groundwater and vadose zone using HYDRUS-based flow package for MODFLOW. Vadose Zone J. Special Issue Vadose Zone Modeling. In press. Tyler, S.W., S. Burak, J. McNamara, A. Lamontagne, J. Selker and J. Dozier. 2007. Fiber optic measurement of distributed base temperatures of two snowpacks. Journal of Glaciology. Submitted Vereecken, H., T. Kamai, T. Harter, R. Kasteel, J. Hopmans, and J. Vanderborght (2007), Explaining soil moisture variability as a function of mean soil moisture: A stochastic unsaturated flow perspective. Geophys. Res. Lett. 34, L22402, doi:10.1029/2007GL031813. Wang, Q., and R. Horton. 2007. Boundary layer theory description of solute transport in soil. Soil Sci. 172:835841. Wang, X.-P., M.H. Young, Z. Yu, and Z.-S. Zhang. 2007 Long-term effects of restoration on soil hydraulic properties in revegetation-stabilized desert ecosystems. Geophys. Res. Lett. doi:10.1029/2007GL031725. Ward, A. L., and Z. F. Zhang. 2007. Effective hydraulic properties determined from transient unsaturated flow in anisotropic soils. Vadose Zone J. 6:913-924. Watanabe, K., N. Toride, M. Sakai, and J. `imonek. 2007. Numerical modeling of water, heat, and solute transport during soil freezing. J. Jpn. Soc. Soil Physics, 106, 21-32. Wehrhan, A., R. Kasteel, J. `imonek, J. Groeneweg, and H. Vereecken. 2007. Transport of sulfadiazine in soil columns experiments and modeling approaches, J. Contam. Hydrology, 89(1-2), 107-135. Wendroth, O. and D.A. Robinson. 2007. Scaling processes in watersheds. Encyclopedia of Water Science 2. Taylor and Francis. In press. Wendroth, O., and N. Wypler. 2007. Unsaturated hydraulic properties: Laboratory evaporation. In: M.R. Carter and E.G. Gregorich (Eds.) Soil sampling and methods of analysis. Canadian Society of Soil Science, 2nd ed., CRC Press, Boca Raton, FL, pp. 1089-1106. Winowiecki, L., E. Somarriba, P. McDaniel, M. Tuller, J. Jonson-Maynard, and A. Falen, 2007. Biogeochemical cycling of base cations in a cacao agroforestry system in the Cabecar Indigenous Territory, Talamanca, Costa Rica. Proc. 15th Int. Cocoa Res. Conf. VOL I, pp. 423-429. Wondzell, S.M., M. 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Res. 43, W07413, doi:10.1029/2006WR005030). Yin, J., M.H. Young, Z. Yu. 2007. Effects of Paleoclimate and time-varying canopy structures on Paleo-water fluxes. J. Geophysical Res. Atmospheres. In press. Young, C., W. Wallender, G. Schoups, G. Fogg, B. Hanson, T. Harter, J. Hopmans, R. Howitt, T. Hsiao, S. Panday, K. Tanji, S. Ustin, and K. Ward. 2007. Modeling shallow water table evaporation in irrigated regions. Irrig. Drain. Syst. 21:119-132. DOI.1007/s10795-007-9024-4. Young, M. H., H. Lin, and B. P. Wilcox. 2007d. Introduction to special section on Bridging Hydrology, Soil Science, and Ecology: Hydropedology and Ecohydrology. Geophys. Res. Lett., 34, L24S20, doi:10.1029/2007GL031998. Young, M.H., E.A. Moran, Z. Yu, J. Zhu, D.M. Smith. 2007b. Reducing saturated hydraulic conductivity of soil with polyacrylamide. Soil Sci. Soc. Am. J. Submitted. Young, M.H., G.S. Campbell, J. Yin. 2007a. Correcting dual-probe heat-pulse readings for ambient temperature fluctuations. Vadose Zone J. In press. Young, M.H., J.J. Tappen, R.B. Susfalk, G.C. Miller. 2007c. Characterizing the risk of using linear anionic polyacrylamide (LA-PAM) to reduce seepage from unlined water delivery canals. J. Soc. Risk Assess. In revision. Yu, Z., Q. Lu, J. Zhu, and E. A. Sudicky, 2007. Spatial and temporal scale effect in simulating hydrologic processes in a watershed. Water Resour. Res. Submitted. Zachara, J M., J. Serne, M. D. Freshley, F. M. Mann, F. Anderson, M. I. Wood, T. Jones, and D. Myers. 2007. Geochemical processes controlling migration of tank wastes in Hanford's vadose zone. Vadose Zone J. 6:985-1003. Zhang Z. F., M. Oostrom, and A.L. Ward. 2007. Saturation-dependent hydraulic conductivity anisotropy for multifluid systems in porous media. Vadose Zone J. 6:925-934. Zhang, J.X., K.-T. Chang, and J.Q. Wu. 2007. Effects of DEM resolution and source on soil erosion modelling: a case study using the WEPP model. Int. J. Geogr. Info. Syst. In press. Zhang, Y., J. Lu, L. Wu, A. Chang, and W.T. Frankenberger Jr. 2007. Simultaneous removal of Chlorothalonil and nitrate by bacillus cereus Strain NS1. Sci. Total Environ. 383: 383-387. Zhao, B., J. Zhang, M. Flury, A. Zhu, Q. Jiang, and J. Bi. 2007. Groundwater contamination with NO3-N from an intensive agriculture system in the North China Plain. Pedosphere. In press. Zheng, W., S. R. Yates, and S. A. Bradford. 2007. Analysis of steroid hormones in dairy manure and wastewaters. Environ Sci. Technol. In press. Zhu, J. 2007. Equivalent parallel and perpendicular unsaturated hydraulic conductivities: arithmetic mean or harmonic mean? Soil Sci. Soc. Am. J. In revision. Zhu, J., and D. Sun. 2007a. Tension-dependent hydraulic conductivity anisotropy of unsaturated soils. Geophysical Res. Lett. Submitted. Zhu, J., and D. Sun. 2007b. Effective soil hydraulic parameters for transient flows in heterogeneous soils. Vadose Zone J. Submitted. Zhu, J., and M.H. Young. 2007a. Uncertainty and sensitivity of evapotranspiration estimates for semi-arid shrublands. J. Am. Water Resour. Assoc. Submitted. Zhu, J., and M.H. Young. 2007b. Sensitivity of unlined canal seepage to hydraulic properties of Polyacrylamide (PAM) treated soil. Soil Sci. Soc. Am. J. Submitted. Zhu, J., M.H. Young, and M.Th. van Genuchten. 2007. Upscaling schemes and relationships for Gardner and van Genuchten hydraulic functions for heterogeneous soils. Vadose Zone J. 6:186-195. Zhuang, J., J.F. McCarthy, J.S. Tyner, E. Perfect, and M. Flury. 2007. In-situ colloid mobilization in Hanford sediments under unsaturated transient flow conditions: Effect of irrigation pattern. Environ. Sci. Technol., 41: 3199-3204. Zlotnik, V. A., T. Wang, J. Nieber, and J. `imonek. 2007. Verification of numerical solutions of the Richards equation using a traveling wave solution. Adv. Water Resour. 30:1973-1980. Abstracts Arora, Bhavna, Binayak Mohanty, Jennifer T. McGuire, J. M. Köhne, and Paolo Castiglione. 2007. Comparison of two-domain models for simulating bromide transport in three different column setups. ASA abstracts, ASA, Madison, WI. Bradford, S. A., S. Torkzaban, F. J. Leij, N. Toride, and J. Simunek, Modeling the coupled effects of pore space geometry and velocity on colloid and nanoparticle transport and retention, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H54C-04, 2007. Bradford, S. A., S. Torkzaban, S. L. Walker, and J. Simunek, Colloid retention in porous media at different scales: Processes and models, American Chemical Society, 81st ACS Colloid and Surface Science Symposium, University of Delaware, Newark, Delaware, June 24-27, 2007. Buchner, J., J. `imonek, J. H. Dane, A. King, J. Lee, D. Rolston, and J. W. Hopmans, Using a process-based numerical model and simple empirical relationships to evaluate CO2 fluxes from agricultural soils, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H13F-1654 INVITED, 2007. Castiglione, P., and J.M. Wraith. 2007. ConvTDR: Software for numerical convolution of time domain signals. ASA abstracts, ASA, Madison, WI. Castiglione, Paolo, Yongping Chen, Jon M. Wraith and Dani Or. 2007. Temperature effects on soil dielectric permittivity. ASA abstracts, ASA, Madison, WI. Conde, K, V. Pacific, B.L. McGlynn, and D. Welsch. 2007. Relationship between soil CO2 concentrations and soil water alkalinity. Posters on the Hill, Counsel for Undergraduate Research and the American Chemical Society. Conference on Capitol Hill, Washington DC. Conde, K., V. Pacific, D. Riveros, B.L. McGlynn, and D. Welsch. 2007. Relationship between soil CO2 concentrations and soil water alkalinity. Undergraduate Scholars Research Conference, Montana State University, Bozeman, Montana. Deng, H, Ye, M, Schaap, M.G., and R. Khaleel, 2007. Uncertainty Assessment of Soil Hydraulic Parameter Estimated From Cokriging and Artificial Neural Network, AGU Fall meeting San Francisco, H23B-1316. Dinwiddie, C., D. Or, S. Stothoff, R. Fedors, J. Pohle, and M. Tuller, 2007. Sensors and Monitoring Techniques for the Deep Unsaturated Zone: Reducing Uncertainty Related to Seepage and Transport in Fractured Rock. Unsaturated Zone Interest Group (UZIG) Meeting, Los Alamos, New Mexico, August 27-30, 2007. Dinwiddie, C.L., D. Or, S.A. Stothoff, R.W. Fedors, J.A. Pohle, and M. Tuller, 2007. Sensors and Monitoring Techniques for the Deep Unsaturated Zone: Reducing Uncertainty Related to Seepage and Transport in Fractured Rock. AGU Fall Meeting, San Francisco, CA, December 10 14, 2007. Dontsova, K., J. `imonek, J. Pennington, and C. Price, Facilitated transport of high explosives in mineral soils, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 283-9, ASA, Madison, 2007. Fayer MJ, and JM Keller. 2007. Recharge Data Package for Hanford Single-Shell Tank Waste Management Areas. PNNL-16688, Pacific Northwest National Laboratory, Richland, WA Forkutsa, I., M. Gribb, J `imonek, J. McNamara, and D. Chandler, Effect of different soil hydraulic properties estimates on soil water content predictions, Dry Creek Experimental Watershed, Idaho, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 183-8, ASA, Madison, 2007. Forkutsa, I., M. Gribb, J. `imonek, J. McNamara, D. Chandler, Estimation of effective soil hydraulic properties at Treeline site, Dry Creek experimental watershed, Idaho, Environmental Sensing Symposium, October 25-26, 2007, Boise State University, Boise, Idaho, 52, 2007. Freedman VL, ZF Zhang, JM Keller, and Y Chen. 2007. Development of Waste Acceptance Criteria at 221-U Building: Initial Flow and Transport Scoping Calculations . PNNL-16585, Pacific Northwest National Laboratory, Richland, WA. Fuentes, R., J. `imonek, L. Cáceres, Mauricio Escudey, Simulacion y modelacion matematica del perfil de temperatura de suelos derivados de materiales volcanicos afectados por un impacto termivo mediante la aplicacion del software HYDRUS -1D, XVII Congreso Latinoamericano de la Ciencia del Suelo, Leon Guanajuato, Mexico, Septiembre 17 al 21, 2007. Gardner, K. and B.L. McGlynn. 2007. Spatio-Temporal Controls of Stream Water Nitrogen Export in a Rapidly Developing Watershed in the Northern Rockies. American Geophysical Union Fall Meeting, 2007. Gebrenegus, Th., B.E. Lassiter, N. Araki, and M. Tuller, 2007. Evaluation of Global and Local Image Binarization Techniques for Quantitative Analysis of X-Ray CT Images of Geological Materials. SSSA International Annual Meeting, New Orleans, LA, November 4-8, 2007. Guber, A. K., Ya. A. Pachepsky, D. Jacques, M. Th. van Genuchten, J. `imonek, T. J. Nicholson, and R. E. Cady, Multimodel prediction of water flow in field soil using pedotransfer functions, AGU Spring meeting, Acapulco, Mexico, 2007. Hanson, B. R., D. M. May, J. Hopmans, and J. Simunek, Drip Irrigation As A Sustainable Practice Under Saline Shallow Ground Water Conditions, USCID Fourth International Conference, Sacramento, CA, 715-725, September 30- October 6, 2007. Hardelauf, H., M. Javaux, M. Herbst, S. Gottschalk, R. Kasteel, J. Vanderborght, H. Vereecken, and J. `imonek, PARSWMS: a parallelized model for simulating 3-D water flow and solute transport in soils, EGU Annual meeting, April, 2007. Jencso, K, B.L. McGlynn, M.N. Gooseff, S.M. Wondzell, K.E. Bencala, and R.A. Payn. 2007. Topographic controls on hillsloperiparian water table continuity in a set of nested catchments, Northern Rocky Mountains, Montana. American Geophysical Union Fall Meeting. Fall, 2007. Jones, S. B., R. Heinse, J. `imonek, M. Tuller and D. Or, Numerical modeling of porous-media hydrodynamics in variable-gravity during parabolic flight, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H53E-1471, 2007. Jones, S.B., R. Heinse, J. Simunek, M. Tuller, and D. Or, 2007. Numerical Modeling of Unsaturated Flows in Variable Gravity During Parabolic Flight. AGU Fall Meeting, San Francisco, CA, December 10 14, 2007. Kleissl, J., J. M. H. Hendrickx, and J. `imonek, HYDRUS Simulations of Surface Temperatures, SPIE, 2007. Kleissl, J., J. M. H. Hendrickx, H. Moreno, and J. `imonek, HYDRUS Simulations of Soil Surface Temperatures, SPIE, 2007. Knight RJ, JD Irving, P Tercier, EJ Freeman, CJ Murray, and ML Rockhold. 2007. "A Comparison of the Use of Radar Images and Neutron Probe Data to Determine the Horizontal Correlation Length of Water Content ." In Subsurface Hydrology: Data Integration for Properties and Processes: Geophysical Monograph Series, vol. 171, ed. David W. Hyndman, Frederick D. Day-Lewis, Kamini Singha, pp. 31-44. American Geophysical Union, Washington, DC. Köhne, J. M. and J. `imonek, Modeling surface runoff and infiltration in soil with mobile and immobile water regions, EGU Annual meeting, April, 2007. Kuroda, S., H. Saito, T. Okuyama, M. Takeuchi, J `imonek, and M. Th. van Genuchten, Quasi 3D model construction of artificial recharge through the vadose zone using time-lapse zero-offset profiling of cross borehole radar, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H41H-06, 2007. M.G. Schaap, M. Porter, and D. Wildenschild, 2007b. Simulating Water Retention Characteristics with Lattice Boltzmann Methods. ASA-CSSA-SSSA meetings in New Orleans, November 4-8, 2007. Poster 183-4, Tuesday November 6, 2007. M.G. Schaap, M. Tuller, A. Guber, and Y. Pachepsky, 2007c. Observing and Simulating Macropore Flow with Computed Tomography and Lattice Boltzmann Methods. ASA-CSSA-SSSA meetings in New Orleans, November 4-8, 2007. Poster 184-7, Tuesday November 6, 2007. Martín, M.A., M. Tuller, A. Guber, C. García-Gutiérrez, F. San José, Y. Pachepsky, and J. Caniego, 2007. CT Data and Analysis for Large Soil Columns. International Meeting on X-ray Computed Tomography of Soil, University of Guelph, Guelph, Canada August 19-22, 2007. Martin, M.A., M. Tuller, A.K. Guber, C. García-Gutiérrez, F. San Jose Martinez, Y.A. Pachepsky, and J.F. Caniego, 2007. Pore Space Statistics From the X-ray CT of Large Undisturbed Soil Columns. AGU Fall Meeting, San Francisco, CA, December 10 14, 2007. McGlynn, B.L., K. Jencso, R. Payn, M. Gooseff, T. Covino, and J. Seibert. 2007. Conceptualizing, testing, and transferring watershed characteristic-runoff generation relationships. Fall AGU [Invited]. McGlynn, B.L., Riveros-Iregui, D.A., Emanuel, R.E., Muth, D.J., Epstein, H.E., Welsch, D.L., Pacific, V.J., and Wraith, J.M., Diurnal Hysteresis between Soil CO2 and Soil Temperature is controlled by Soil Water Content. American Geophysical Union Fall Meeting, 2007. McNamara, R., B.L. McGlynn, K. Gardner, and P. Jenkins. 2007. In-Stream Nitrate Immobilization Across Development Gradients and Stream Network Position in a Rapidly Developing Mountain Watershed, West Fork of the Gallatin River, Big Sky, Montana. American Geophysical Union Fall Meeting, 2007. Muth, D.J., H. Epstein, R. Emanuel, B.L. McGlynn, D. Welsch. 2007. Net Ecosystem Exchange in a Forested Montane Watershed: Trends and Trials in Complex Terrain. Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract B21D-06. Oostrom M, PD Thorne, GV Last, and MJ Truex. 2007. Modeling of Carbon Tetrachloride Flow and Transport in the Subsurface of the 200 West Disposal Sites: Large-Scale Model Configuration and Predicted Future Carbon Tetrachloride Distribution beneath the 216-Z-9 Disposal Site. PNNL-17181, Pacific Northwest National Laboratory, Richland, WA. Pacific, V.J., D.A. Riveros-Iregui, B.L. McGlynn, D.L. Welsch, and H.E. Epstein. 2007. Comparison of soil CO2 concentrations and surface CO2 efflux across riparian-hillslope transitions: wet versus dry growing seasons. American Geophysical Union Fall Meeting. Fall, 2007. Pang, L., M. McLeod, J. Aislabie, J. `imonek, M. Close, and R. Hector, Removal rates of faecal bacteria and phage viruses in 10 NZ soils under dairy-shed effluent irrigation, Proc. of New Zealand Hydrological Society Conference, Rotorua, New Zealand, 20-23 November 2007. Payn, R., M. Gooseff, B.L. McGlynn, K.E. Bencala, and S.M. Wondzell. 2007. Multiple spatial scales of surface water - groundwater exchange in a headwater stream in Montana, USA. 2007 Geological Society of America Annual Meeting, Denver. Payn, R., M. Gooseff, B.L. McGlynn, S. Thomas. 2007. Sensitivity of whole-stream metabolism estimates to fully characterized stream-groundwater exchange. North American Benthological Society Annual Meeting. #497. Payn, R.A., M.N. Gooseff, B.L. McGlynn, K.E. Bencala, S.M. Wondzell, K. Jencso. 2007. Relationships between stream ground water exchange and topography of the channel, valley, and watershed. American Geophysical Union Fall Meeting. Fall, 2007. Peterson RE, RJ Serne, PD Thorne, MD Williams, and ML Rockhold. 2007. Uranium Contamination in the Subsurface Beneath the 300 Area, Hanford Site, Washington . PNNL-17034, Pacific Northwest National Laboratory, Richland, WA. Pontedeiro, E. M., J. `imonek, M. van Genuchten, and R. Cotta, Performance assessment modeling of a radioactive mining waste disposal site, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 184-5, ASA, Madison, 2007. Pontedeiro, E., M. Cipriani, M. Th. van Genuchten, and J. `imonek, Evaluation of the transport of natural radioactive materials in large lysimeters using Hydrus-1D, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H53F-1496, 2007. Porter, M.L, D. Wildenschild, and M.G. Schaap, 2007. Investigating Interfacial Area in a Multiphase Porous System Using Computed Microtomography and Lattice-Boltzmann Simulations, AGU Fall meeting San Francisco, H43J-04. Riveros-Iregui, D.A., McGlynn, B.L., Epstein, H.E., Welsch, D.L., Pacific, V.J., Muth, D.J., Emanuel, R.E., Jencso, K.G., Wraith, J.M., 2007. Tenderfoot Creek Experimental Forest, Montana: Measuring and modeling carbon and water fluxes from point to watershed scales (Part I). AmeriFlux Annual Meeting, October 17-19, Boulder, CO. Riveros-Iregui, D.A., McGlynn, B.L., Pacific, V.J., Epstein, H.E., and Welsch, D.L, Soil CO2 Efflux Variability in Complex Terrain: Towards Estimation of Watershed-Level Rates. American Geophysical Union Fall Meeting, 2007. Riveros-Iregui, D.A., McGlynn, B.L., Pacific, V.J., Epstein, H.E., Welsch, D.L. and Jencso, K.G. Soil CO2 Efflux from a Subalpine Catchment. National Center for Atmospheric Research "Regional Biogeochemistry: Needs and Methodologies." June 2007, Boulder, CO. Saito, H., J `imonek, A. Tuli, and J. W. Hopmans, Improving heat pulse probe sensitivity without changing its geometry, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H53F-1477, 2007. Saito, H., J. `imonek, J. W. Hopmans, and A. Tuli, Numerical evaluation of alternative heat pulse probe designs and analyses, 2007 Environmental Sensing Symposium, October 25-26, 2007, Boise State University, Boise, Idaho, 119-123, 2007. Saito, H., K. Seki, and J. `imonek. Variably-saturated water flow in kriged hydrological parameter fields, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 282-5, ASA, Madison, 2007. Schaap, M., M. Tuller, A. Guber, and Y. Pachepsky, 2007. Observing and Simulating Macropore Flow with Computed Tomography and Lattice Boltzmann Methods. SSSA International Annual Meeting, New Orleans, LA, November 4-8, 2007. Schaap, M.G, M. Tuller, A. Guber, M.A. Martin, F.S. Martinez, and Y. Pachepsky, 2007. Macropore Flow in Soil Columns: Investigations with Computer Tomography and Lattice Boltzmann Simulations. AGU Fall Meeting, San Francisco, CA, December 10 14, 2007. Schaap, M.G. 2007. Hydraulic Functions, Lecture in Vadose Zone Modeling Course (Lead J.W. Hopmans), University of California, Davis. April 26, 2007. Schaap, M.G. 2007. Lattice Boltzmann Methods for Interfacial Processes in Porous Media. Invited presentation. Workshop on Modelling, Analysis, and Simulation of Multiscale Nonlinear Systems, Oregon State University, Corvallis, June 25-29, 2007. Schaap, M.G. 2007. Soil Physics and Micro-Meteorology at the Soil-Atmosphere Interface. Invited lecture for the Atmospheric Sciences Department, University of Arizona. October 18, 2007. Schaap, M.G., M. Tuller, A. Guber, M.A. Martin, F.S. Martinez, and Y. Pachepsky, 2007d. Macropore Flow in Soil Columns: Investigations with Computer Tomography and Lattice Boltzmann Simulations. AGU Fall meeting San Francisco, H53E-1457. `imonek, J., K. Dontsova, J. Pennington, and H. Saito, Implementation of new physical and chemical nonequilibrium models into the HYDRUS-1D software package and their application to column experiments with explosives under saturated and unsaturated conditions, Army Research Office Meeting, Springfield, Virginia, January 31-February 1, 2007. Schuh, M. F.X.M. Casey, and H. Hakk. 2007. Farm-scale reconnaissance of Estrogens in subsurface waters. In Annual Meetings Abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Seo, H. S., J. `imonek, and E. P. Poeter, Documentation of the HYDRUS Package for MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model, GWMI 2007-01, International Ground Water Modeling Center, Colorado School of Mines, Golden, Colorado, 96 pp., 2007. `imonek, J., H. Saito, J. W. Hopmans, and A. Tuli, Numerical evaluation of alternative heat pulse probe designs and analyses, Environmental Sensing Symposium, October 25-26, 2007, Boise State University, Boise, Idaho, 35, 2007. `imonek, J., K. Dontsova, and J. Pennington, Implementation of colloid and colloid-facilitated solute transport module into the HYDRUS-1D software package: numerical verification and applications, ARO meetings, September 23-24, 2007, Vicksburg, MS, 2007. Tartakovsky AM, AL Ward, and P Meakin. 2007. Pore-scale Simulations of Drainage of Heterogeneous and Anisotropic Porous Media. PHYSICS OF FLUIDS, vol. 19 (10), pp. NIL 240-NIL 247. Truex MJ, VR Vermeul, PE Long, FJ Brockman, M Oostrom, S Hubbard, RC Borden, and JS Fruchter. 2007. Treatability Test Plan for an In Situ Biostimulation Reducing Barrier . PNNL-16424 Rev. 1, Pacific Northwest National Laboratory, Richland, WA. Tuli, A., T. Kamai, H. Saito, J. Hopmans, and J. `imonek, Experimental and numerical sensitivity analyses of heat pulse probe designs, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 88-8, ASA, Madison, 2007. Tuller, M., and Th. Gebrenegus, 2007. Assessment of the Impact of Physico-Chemical Factors on Initiation and Evolution of Dessication Cracks in Bentonite-Sand Mixtures with X-Ray Computed Tomography. SSSA International Annual Meeting, New Orleans, LA, November 4-8, 2007. Tuller, M., and Th. Gebrenegus, 2007. Evaluation of Local and Global Segmentation Techniques for Quantitative Analysis of X-Ray CT Images of Geological Materials. AGU Fall Meeting, San Francisco, CA, December 10 14, 2007. Twarakavi, N. K. C., J. `imonek, and M. Schaap, New pedotransfer functions for estimating soil hydraulic parameters using the Support Vector Machines method, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 180-9, ASA, Madison, 2007. van Genuchten, M., Th., F. J. Leij, N. Toride, and J. `imonek, Analytical solute transport modeling using the STANMOD computer software package, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 284-2, ASA, Madison, 2007. Vermeul VR, MD Williams, BG Fritz, RD Mackley, DP Mendoza, DR Newcomer, ML Rockhold, BA Williams, and DM Wellman. 2007. Treatability Test Plan for 300 Area Uranium Stabilization through Polyphosphate Injection. PNNL-16571, Pacific Northwest National Laboratory, Richland, WA. Wang, T., V. A. Zlotnik, J. `imonek, and D. Wedin, Using process-based models and pedotransfer functions for soil hydraulic characteristics to estimate groundwater recharge in semi-arid regions: Is this a right approach? Paper #128602, GSA Denver Annual Meeting, 2831 October, 2007. Ward AL, SO Link, CE Strickland, K Draper, and RE Clayton. 2007. 200-BP-1 Prototype Hanford Barrier Annual Monitoring Report for Fiscal Years 2005 Through 2007 . PNNL-17176, Pacific Northwest National Laboratory, Richland, WA. Ward AL. 2007. Geotechnical, Hydrogeologic and Vegetation Data Package for 200-UW-1 Waste Site Engineered Surface Barrier Design . PNNL-17134, Pacific Northwest National Laboratory, Richland, WA. Wellman DM, EM Pierce, M Oostrom, and JS Fruchter. 2007. Experimental Plan: 300 Area Treatability Test: In Situ Treatment of the Vadose Zone and Smear Zone Uranium Contamination by Polyphosphate Infiltration . PNNL-16823, Pacific Northwest National Laboratory, Richland, WA. Winowiecki, L., E. Somarriba, P. McDaniel, J. Johnson-Maynard, M. Tuller, and A. Falen, 2007. Biogeochemical Cycling of Base Cations in a Diverse Cacao Agroforestry System, Cabécar Indigenous Territories, Talamanca, Costa Rica. 2nd International Symposium on Multi-Strata Agroforestry Systems with Perennial Crops: Making Ecosystem Services Count for Farmers, Consumers and the Environment, CATIE, Turrialba, Costa Rica, 17-21 September 2007. Zhang ZF, JM Keller, and CE Strickland. 2007. T Tank Farm Interim Surface Barrier Demonstration--Vadose Zone Monitoring Plan . PNNL-16538, Pacific Northwest National Laboratory, Richland, WA. Zhang, Z.F., and R. Khaleel. 2007. Comparison of models of saturation-dependent anisotropy in unsaturated hydraulic conductivity. PNNL-16886, Pacific Northwest National Laboratory, Richland, Washington.

Impact Statements

*Models for colloid retention, release and transport under unsaturated flow conditions in provide a better understanding of colloid fate in the vadose zone. *Better understanding on the fate of hormones in soils is useful in developing management methods for handling hormones in animal manures or from waste treatment facilities. *Determined crack porosity values indicate that samples saturated with lower concentrated solutions are more susceptible to cracking.
*Under high soil salinity levels caused by saline waters, subsurface drip irrigation of processing tomatoes is highly profitable. *Critical gaps in our knowledge are filled concerning emerging issues of water availability in space and time and watershed processes controlling stream biogeochemistry, carbon cycling, global change ecology, and greenhouse gas emissions. *Ash cover, both measured on the ground and remotely, was the variable most significantly correlated to strong water repellency after the Hayman Fire enabling estimates of sediment load and water quantity.
*A statewide soil moisture network for the State Climatology Office is upgraded by Wyoming scientists creating better estimates for fire, drought and water availability estimates.. *Heat pulse sensors can be used to obtain accurate measurements of apparent thermal conductivity and apparent volumetric heat capacity which, together with soil temperature data and permit accurate monitoring of soil heat flux under freezing and thawing conditions. *Dissolved organic matter acts as a surfactant and facilitates water transport.
*The portable TDR circuit facilitated rapid mapping of water content in rugged terrain and has potential benefit for field use for anyone with TDR100 and datalogging instrumentation. *Integrating field studies and landscape analysis will be valuable for the refinement of hydrological and water quality models on the catchment scale *Accurate estimates of the extent and location of drained land are important for determining the effect of agricultural practices on water quality at local, regional, and national scales.
*Simulation results suggest that if DWM can be practically implemented on a large scale, particularly in the southern states of the region, the amount of NO3-N entering surface waters from agricultural systems can be significantly reduced. *Process-based models can play an important role in quantifying the comprehensive effects of management alternatives on agricultural production and the environment. *Work will lead to improved functionality of disposal pond caps, representing critical inputs to environmental aspects of energy production. *Incorporating land use/land cover and topography data provides critical insight for land managers, planners and consulting agencies is developed to examine the potential impacts of human alteration of natural landscapes on stream water quality.

Date of Annual Report: 02/27/2009

Report Information

Annual Meeting Dates: 01/05/2009 - 01/07/2009
Period the Report Covers: 01/01/2008 - 12/01/2008

Participants

The participating project members and visitors are listed as follows:

Members:
1. Barnes, Dave (new member) Univ. of Alaska, Fairbanks, AK
2. Berli, Markus (new member) Desert Research Institute DRI,
Las Vegas, NV
3. Casey, Frank North Dakota State University,
Fargo, ND
4. Chief, Karletta (new member) Desert Research Institute DRI,
Las Vegas, NV
5. Evett, Steve USDA-ARS, Bushland, TX
6. Ferre, Ty Univ. of Arizona, Tucson, AZ
7. Green, Tim USDA-ARS, Fort Collins, CO
8. Harter, Thomas Univ. of California, Davis, CA
9. Hopmans, Jan Univ. of California, Davis, CA
10. Horton, Bob Iowa State University, Ames, IA
11. Jacobsen, Jeff (advisor W1188) Montana State University,
Bozeman, MT
12. Jones, Scott Utah State University, Logan, UT
13. Kelleners, Thijs Univ. of Wyoming, Laramie, WY
14. Kluitenberg, Gerard Kansas State University,
Manhattan, KS
15. Nieber, John Univ. of Minnesota, St. Paul, MN
16. Ochsener, Tyson Oklahoma State Univ.,
Stillwater, OK
17. Skaggs, Todd USDA-ARS, Salinity Lab,
Riverside, CA
18. Schaap, Marcel Univ. of Arizona, Tucson, AZ
19. Schwartz, Robert USDA-ARS, Bushland, TX
20. Simunek, Jirka Univ. of California, Riverside,
CA
21. Tuller, Markus Univ. of Arizona, Tucson, AZ
22. Warrick, Art Univ. of Arizona, Tucson, AZ
23. Wendroth, Ole Univ. of Kentucky, Lexington, KY
24. Wu, Laosheng Univ. of California, Riverside,
CA
25. Young, Michael Desert Research Institute DRI,
Las Vegas, NV
26. Zhang, Fred Batelle Pacific NW National
Lab, Richland, WA
27. Zhu, Jianting Desert Research Institute DRI,
Las Vegas, NV

Guests:
28. Bell, Jourdan USDA-ARS, Bushland, TX
29. Berger, Phyllis Univ. of Arizona, Tucson, AZ
30. Chorover, Jon (inv. speaker) Univ. of Arizona, Tucson, AZ
31. Crimmins, Mike (inv. speaker) Univ. of Arizona, Tucson, AZ
32. Dontsova, Katerina Univ. of Arizona, Tucson, AZ
33. Gallo, Pamela Univ. of Arizona, Tucson, AZ
34. Heckman, Kate Univ. of Arizona, Tucson, AZ
35. Huxman, Travis (inv. speaker) Univ. of Arizona, Tucson, AZ
36. Iassonov, Pavel Univ. of Arizona, Tucson, AZ
37. Meding, Mercer Univ. of Arizona, Tucson, AZ
38. Rasmussen, Craig (inv. speaker) Univ. of Arizona, Tucson, AZ
39. Rushforth, Richard Univ. of Arizona, Tucson, AZ
40. Sakai, Masaru Univ. of California, Riverside,
CA
41. Silvertooth, Jeffrey Univ. of Arizona, Tucson, AZ
42. Stumpp, Christine Univ. of California, Riverside,
CA
43. Troch, Peter (inv. speaker) Univ. of Arizona, Tucson, AZ
44. Wierenga, Peter Univ. of Arizona, Tucson, AZ

Brief Summary of Minutes

The annual meeting of the Multi-State Regional Soil Physics Research Project W-1188 was called to order by Ole Wendroth (Chair) at 8:00 am on Monday, January 5, 2009. The participating project members and visitors are listed as follows:

MONDAY, JANUARY 5, 2009
8:00 am: Ole Wendroth, W1188 chair, welcomes the participants and presents the meeting theme. Five speakers from ecology (Travis Huxman), geochemistry (Jon Chorover), pedology (Craig Rasmussen), meteorology (Mike Crimmins), and hydrology (Peter Troch) were invited to present their views and opinions on potential contributions of the W1188 group to their respective disciplines. Jeffrey Silvertooth, SWES Department Head, welcomes the participants on behalf of the University of Arizona and the SWES Department.
8:30 am: Jon Chorover - Keynote Presentation
After introducing meeting attendees, Dr. Jon Chorover presented an overview of his research on co-occurrence of organic and inorganic weathering processes. Throughout the presentation, Jon provided linkage between weathering processes and changes of physical and hydraulic properties of soils.
9:45 am: Student Poster Presentations
During the break graduate students from the UA SWES and HWR Departments took the opportunity to present and discuss their research projects with W-1188 members.
10:15 am: Technical Presentations
Thomas Harter (UCD) introduced a new concept to derive effective hydraulic parameters from simple patterns. Fred Zhang (PNNL) presented the computer code STOMP-WNE-R for simulating the transport of water and multi-component gas and energy transport. Jan Hopmans (UCD) introduced new designs for heat pulse probes for measurement of water fluxes, and gave an overview of the newly established California NSF Critical Zone Observatory. Marcel Schaap (UA) showed recent advances in Synchrotron Tomography that he utilized in conjunction with lattice Boltzmann modeling to directly predict the pressure-saturation relationship. Scott Jones (USU) presented recent work on the frequency-dependence of soil complex permittivity as key to determination of soil properties from EM measurements.
1:00 pm: Craig Rasmussen - Keynote Presentation
After a short lunch break, Dr. Craig Rasmussen provided an interesting talk about interrelations between ecosystem patterns and soil water dynamics along climatic gradients and pointed to the many opportunities for collaborative research between pedology and soil physics.
2:15 pm: Technical Presentations
Francis Casey (NSU) gave an overview of two recent research projects on nitrate mobility below center pivot irrigation and on the effect of soil properties on fate and transport of Estradiol. Markus Berli (DRI) presented a Microtomography and modeling study on soil compaction by plant roots. Todd Skaggs (US Salinity Lab) introduced a new root zone modeling approach to estimate groundwater recharge from irrigation of vegetable crops, and reported about performance of traditional subsurface irrigation systems with clay pots in India.
4:05 pm: Peter Troch - Keynote Presentation
Dr. Peter Troch provided an excellent talk illustrating the application of isotope chemistry for estimation of travel times through catchments. He emphasized the importance and impact of soil physics for hydrology.
5:15 pm: Technical Presentations
Karletta Chief (DRI) introduced the capabilities of the new DRI SEPHAS Lysimeter facility. Michael Young (DRI) continued to present the first measurements obtained with the heavily instrumented lysimeters. Jianting Zhu (DRI) presented results on hydraulic conductivity of layered soil systems with structured heterogeneity. Thijs Kelleners (UW) reported measurement and modeling results for the water and energy balance of vegetated areas with snow accumulation.
7:00 pm: Dinner, Social, and Group Discussion

TUESDAY, JANUARY 6, 2009
8:00am Business Meeting
Ole Wendroth (chair) called the business meeting to order at 8:00 am and requested approval of the 2007 activity report and 2008 meeting minutes. Jan Hopmans moves to approve the report and the minutes, Ty Ferre seconds, and the group unanimously approves the activity report for the year 2007 and 2008 meeting minutes.
Michael Young nominates Karletta Chief and Markus Berli (both DRI) as new W1188 members. After Karletta and Markus introduce themselves, Markus Tuller moves to approve, Scott Jones seconds, and the committee unanimously approves Karlettas and Markuss membership. Ole Wendroth asks Jeff Jacobsen (Administrative Supervisor) to consider the new members. Jeffs agreement is required because both are not affiliated with an Experiment Station.
The committee nominates two candidates for becoming the next secretary: Marcel Schaap (UA) and Scott Jones (USU). After consultation between Marcel and Scott, Marcel prefers Scott to take over this responsibility in 2009. Scott was unanimously approved by the committee, and he accepts.
Jan Hopmans proposed changes to the W1188 webpage to create a platform for information exchange among group members. After discussion the group agreed to setup a protected ftp site. This will streamline submission of activity reports in the coming years. Jan Hopmans moves to setup the site, Scott Jones seconds, and the committee unanimously approves. Frank agreed to setup the site at NDSU.
Thijs Kelleners proposed to discontinue distributing paper copies of the activity reports. A poll showed that the majority of group members prefer to have hardcopies. The committee agrees to distribute hardcopies at future meetings.
Ole Wendroth and Jeff Jacobsen suggest providing more focused activity reports with emphasis on accomplishments and impacts. Shorter reports will significantly reduce the workload for the secretary and the administrative supervisor, who is responsible for submission of the report to CRIS. Jan Hopmans moves to change the report format to a shorter version, Ole Wendroth seconds, and the committee unanimously approves. It was agreed that each state/institution submits a one- to two-page report with accomplishments and impacts. Jeff Jacobsen will provide more details regarding the preferred format (CRIS) prior to the next meeting.
Mike Young provided an update on the status of the W1188 renewal proposal and requested contributions from group members and the writing committee.
Jeff Jacobsen (MSU) provided the administrative report. Jeff pointed to the many changes occurring within USDA associated to changes to the farm bill. Based on his knowledge these changes wont impact multistate research projects, but there will be transformations to the Cooperative State Research, Education, and Extension Service (CSREES). There will be a new National Institute for Food and Agriculture (NIFA) that is authorized to direct more funding towards competitive research including basic and applied research and extension and education. There are a number of upcoming deadlines that W1188 should not miss. Jeff is working with the writing team to get the renewal proposal submitted in time. Gerard Kluitenberg on behalf of the group thanked Jeff for his continued service to W1188.
Jan Hopmans and Michael Young suggest to more closely work with other multistate groups (e.g., W1007, W1045) and maybe organize a joint annual meeting or send W1188 ambassadors to meetings. Jan Hopmans will attend the next W1007 meeting in June in Las Cruces, NM. The committee unanimously agreed to actively pursue closer collaborations with other multistate groups.
9:15 am: Mike Crimmins - Keynote Presentation
Dr. Mike Crimmins provided the forth keynote lecture on Strategies for Integrating Soil and Climate Sciences. He pointed to the many opportunities for W-1188 to collaborate and provide expertise for drought monitoring and climate change projects.
11:00 am: Technical Presentations
Laosheng Wu (UCR) presented a diffusion/raindrop-dispersion model for predicting dissolved chemical transfer between soil surface and overland flow. Tim Green (USDA) showed recent results for scaling of spatial soil structures to link structural patterns to soil water dynamics. Jiri Simunek (UCR) provided his annual update on new applications and modifications to the HYDRUS 1D and 2D/3D numerical codes.
1:00 pm: Technical Presentations
Ty Ferre (UA) presented a study regarding the sampling area (resolution) of environmental sensors. Art Warrick (UA) presented a computationally efficient approach to calculate infiltration from 2D/3D sources.
2:15 pm: Travis Huxman - Keynote Presentation
The meeting commenced with the final keynote lecture by Dr. Travis Huxman. Travis illustrated how the landscape water balance and associated biotic/abiotic interactions change with respect to shifts in ecology and climate.
4:00 pm: Technical Presentations
Steve Evett (USDA) provided an overview of newly constructed weighing lysimeter facilities in Jordan and China. Robert Schwartz (USDA) presented a study on calibration of TDR using the complex dielectric mixing model. Tyson Ochsner (OSU) presented a new approach to measure profile soil water dynamics with coated waveguides. After a moment of silence in memory of Sasha Globus, Robert Horton (ISU) presented new ways for insitu determination of soil water evaporation with heat pulse probes. Gerard Kluitenberg (KSU) introduced a new project aimed at establishing a database with field-measured physical and hydraulic data and corresponding soil descriptions for testing pedotransfer functions. John Nieber (UM) presented a new approach for multi-scale quantitative hydrologic analysis of water resources sustainability. Ole Wendroth (UK) presented a recent study on effects of rainfall timing and intensity on field-scale solute transport.
6:45 pm: Synthesis and Discussion
After the final technical presentation, Ole Wendroth reads an encouraging message from Don and Joanne Nielsen, who were greatly missed at this years meeting. Jon Nieber nominates Dave Barnes (Univ. of Alaska Fairbanks) as a new member of the W1188 group. After a brief introduction of Dave, Gerard Kluitenberg moves to approve, Scott Jones seconds, and the committee unanimously approves Daves membership. The meeting continued with a discussion about the new meeting format and the venue for the 2010 meeting. There was unanimous agreement among group members that the new format with invited speakers and graduate student involvement was very successful and should be kept for future meetings. Several locations including Bushland (TX), Fort Collins (CO), Riverside (CA), Tucson (AZ), and Las Vegas (NV) were proposed for the 2010 meeting. A formal vote was not conclusive, but narrowed potential locations to Bushland and Las Vegas. Due to the advanced time, the decision and revote was tabled for Wednesday. Jan Hopmans also suggested a future meeting in Hawaii. He proposed to invite Ali Fares (Univ. of Hawaii) to join the W-1188 group to have a local organizer.
7:15pm Dinner and Social

WEDNESDAY, JANUARY 7, 2009
8:15 am: Introduction of the Biosphere 2 Project
Travis Huxman, director of the B2 Earthscience Institute presented an overview of the B2 outreach, education, and research infrastructure. Of specific interest for the W1188 group was a planned long-term experiment (currently in the design stage) focused on the fate of water on landscapes. The experiment comprises construction and instrumentation of three large hillslopes within the B2 facility to investigate how precipitation is partitioned upon the land surface into evaporation, transpiration, infiltration, deep percolation, run-off and stream flow, and how weathering processes and vegetation dynamics modify hillslope hydrology with time.
After a lively discussion, W1188 members had the opportunity to tour the facility with its rainforest, marine, savannah, and desert biomes and the construction site for the hillslope experiment.
11:45 am: Concluding Remarks
After the behind-the-scene tour of B2 the group gathered for final remarks and discussions. Another attempt to settle on a location for the 2010 meeting failed and it was decided to conduct an email poll. The meeting was officially adjourned at 12:30 pm.

Respectfully submitted,

Markus Tuller
Secretary

*The poll conducted after the meeting showed that the majority of members prefer to go back to Las Vegas for the 2010 meeting.

Accomplishments

OBJECTIVE 1: To develop and improved understanding of the fundamental soil physical properties and processes governing mass and energy transport, and the biogeochemical interactions these mediate. Nevada applied synchrotron X-ray microtomography to study effects of physical rhizosphere properties on root growth, water and nutrient uptake. Air permeability measurements were tested as a viable alternative to water- and textured-based methods to rapidly map changes in saturated hydraulic conductivity due to soil development and land use. A study on application of polyacrylamide (PAM) to reduce seepage losses in earthen water delivery canals was completed. The U.S. Salinity Laboratory conducted studies to characterize surface chemistry and transport behavior of pathogenic E. coli. Cell surface macromolecules, steric stabilization, cell-cell interactions, and pore structure were found to play important roles in cell retention behavior in the sand. UC Riverside examined fate and transport behavior of pharmaceutical and personal care products (PPCPs) and endocrine disrupting compounds (EDCs) through observations in experimental turf fields irrigated with EDCs and PPCPs. Pollution risk screenings identified six compounds with potential to contaminate groundwater under irrigated turf grass. UC Davis in collaboration with UC Riverside developed a new mathematical model SOILCO2 built into the HYDRUS-1D code to assess impact of agricultural management practices and land use on soil carbon storage and greenhouse gas emissions. Field-scale CO2 emissions measured in the Sacramento Valley were evaluated with SOILCO2. Another study at UC Davis revealed the dominant role of soils controlling the physical and chemical hydrology of contrasting vernal pools. Vernal pools are small depressional wetlands found in California. They are among the few ecosystems still dominated by native flora and are critical habitat for numerous rare species. The University of Arizona conducted theoretical and experimental studies with X Ray CT to investigate applicability of polypropylene fiber amendments to alleviate initiation and evolution of desiccation cracks in bentonite liners. Already a small amount of fibers improved mechanical liner stability and led to significant reduction of cracking. These findings are important for advanced and cost-efficient barrier design. Utah State University successfully launched a second experiment for optimization of root zone substrates to the International Space Station (ISS) and measurements in long term microgravity are currently being carried out. This second experiment monitors water retention and oxygen diffusion to determine the impact of microgravity on fluid distribution and transport in porous media. The University of Delaware conducted novel pore-scale experiments with laser scanning confocal microscopy to quantify and model colloid retention behavior in saturated and unsaturated porous media. Washington State University studied insitu colloid mobilization in Hanford sediments under transient flow conditions with column batch experiments and used the ADE with first-order colloid release reaction to analyze the experimental data. They found that capillary forces are controlling colloid release. The University of Wyoming developed a distributed model for calculation of the water and energy balance in mountainous areas prone to snow accumulation. Calibration and validation was conducted using data from a Northeast facing slope in the Dry Creek experimental watershed in Idaho. North Dakota State University conducted research on nitrate mobility below center pivot irrigation and on the effect of soil properties on fate and transport of Estradiol. Iowa State University performed a series of field studies to determine insitu soil-water evaporation dynamics from heat balance. Three-needle heat-pulse probes were installed at multiple depths in the upper centimeters of bare and cropped field plots. The probes provided temporal measurements of soil temperature, thermal properties, and water content, which allowed calculation of the subsurface sensible heat balance. PNNL developed a new module (STOMP-WNE) for the Subsurface Transport over Multiple Phase (STOMP) numerical simulator to model gas transport with one or more components in variably saturated geologic media. The University of Kentucky established field experiments to quantify leaching behavior of FBA (Fluor-Benzoic-Acid) and Bromide under different irrigation scenarios. OBJECTIVE 2: To develop and evaluate instrumentation and methods of analysis for characterizing mass and energy transport in soils at different scales. Researchers from Nevadas universities constructed a weighing lysimeter facility in Boulder City. Four well-instrumented weighing lysimeters with a live mass of approximately 28,000 kg and a resolution of ± 100g are devoted to investigate near-surface interactions of soil, water, biota, and atmospheric processes that affect desert environments. USDA-ARS Bushland (TX) designed and constructed a large weighing lysimeter facility in the Jordan River valley as part of the Middle Eastern Regional Irrigation Management Information Systems (MERIMIS) project of the USDA-ARS Office of International Programs. USDA-ARS Fort Collins (CO) further enhanced their Object Modeling System (OMS) to better support visual assembly of spatially distributed models for different space-time scales. The U.S. Salinity Lab developed new cell preparation methods for studying transport and retention of Escherichia coli D21g. For a given ionic strength condition, it was found that cells prepared by filtration were more negatively charged and hydrophobic, and exhibited greater transport potential than cells prepared by centrifugation. UC Riverside developed a new analytical method for simultaneous determination of pharmaceuticals and personal care products (PPCPs), endocrine disrupting compounds (EDCs), and estrogenic compounds in wastewater irrigated soils by means of Gas Chromatography-Mass Spectrometry. UC Davis in collaboration with Kansas State University designed an innovative button heat pulse probe (BHPP) for accurate soil water content measurements. The BHHP is highly sensitive to soil moisture because of the central placement of the thermistor. In addition, heat pulse methodology was further improved for accurate water flux density (WFD) measurements with a resolution of 1 cm/day. The University of Arizona developed new procedures for segmentation of X-Ray CT images of natural porous media, which is a significant contribution to microporous media research with objectives ranging from theoretical aspects of fluid and interfacial dynamics to practical applications such as (D)NAPL transport and dissolution. Another project was focused on the development of sample preparation and operation procedures for particle size analysis with laser diffractometry. Utah State University in collaboration with the University of Arizona applied geophysical measurement techniques (ERI and EMI) to determine their effectiveness for mapping of mine tailings. They further advanced geostatistical analysis of soil maps in collaboration with Stanford University. Washington State University tested suitability of centrifuges for studying colloid transport in saturated porous media. Theoretical predictions of colloid deposition in a porous medium agreed well with experiments. Kansas State University initiated a new project in collaboration with NRCS aimed at establishing a database with field-measured physical and hydraulic data and corresponding soil descriptions for testing pedotransfer functions. Oklahoma State University developed and tested a new TDR system with 1-m, coated waveguides for measuring soil profile water storage at the plot scale. The system is easier to install, uses fewer sensors, provides more spatial replication, and produces less site disturbance than common TDR systems. Iowa State University used laboratory and field experiments to evaluate the performance of a new, perforated heat flux plate to reduce flow distortion for environmental applications. Accurate measurement of heat flux is essential to optimize structural and process design and to improve understanding of energy transfer in natural systems. OBJECTIVE 3: To develop and evaluate scale-appropriate methodologies for the management of soil and water resources. Nevada contributed to the restoration of military lands. They evaluated the seedbed microclimate associated with the restoration of disturbed lands in the Mojave Desert. Results show that under prevailing hot and dry climatic conditions, soil microclimate is a hostile environment. Although seedlings germinated, survival after three months was negligible. The U.S. Salinity Lab implemented nutrient management plans (NMP) for dairy lagoon water application at three sites. They monitored fate and transport of salts, nutrients, and indicator microorganisms to develop management recommendations for improved NMP performance to protect groundwater from microorganism contamination. In another project they developed design and operation criteria for subsurface irrigation with baked clay pipes, a cost-efficient alternative to drip irrigation systems, which are not affordable for rural farming communities in developing countries. UC Riverside shifted research focus from water quantity issues towards water quality and has developed a number of new numerical HYDRUS codes for chemical transport, preferential/nonequilibrium flow and transport, contaminant transport, and coupled transport of water, vapor and energy. UC Riverside in collaboration with UCs Irvine, Merced, Berkeley, and Santa Barbara, established a new NSF funded Critical Zone Observatory in the Southern Sierra to answer forefront questions at the cross-roads of hydrology, geomorphology, soil science, geophysics, ecology, and geochemistry. Soil moisture, sap flow, and leaf potential measurements around a white fir are used to investigate how soil environmental stresses impact forest ecosystems across the rainfall-to-snow-dominated transition zone. UC Riverside developed a novel conceptual model for flow and transport of bio-colloids/pathogens through macroporous soils to assess potential risks of groundwater contamination with Cryptosporidium parvum. The University of Wyoming conducted a study to determine leaching potential of trace elements from Coalbed Methane production water disposal ponds. Analysis of a pond in Wyomings Powder River Basin suggests that the leaching potential from the unlined pond is low. North Dakota State University used sand column experiments to examine atrazine removal by Agrobacterium radiobacter immobilized in phosphorylated-polyvinyl alcohol compared to free J14a cells. The atrazine breakthrough results indicated that the immobilized dead J14 cells retarded atrazine transport, and that atrazine degradation capacity for the immobilized cells was not significantly different from the free cells. Kansas State University in collaboration with the Kansas Geological Survey measured water-table fluctuations to estimate the impact of various salt-cedar control activities on the ground-water resources of the Cimarron River alluvial aquifer. The University of Kentucky performed experiments to improve the understanding of nitrogen fertilizer response of winter wheat. Application treatments were not varied randomly in space but in a continuous sinusoidal pattern. It was obvious that nitrogen response is not unique but varies systematically across the landscape. USDA-ARS Bushland conducted the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2008. The objective of the campaign was to evaluate, compare and regionally integrate evapotranspiration flux estimates made at different scales and with different instrumentation, using ground truth from the four large weighing lysimeters. OUTCOMES: New measurements of soil water movement has increased efficiency and applicability associated with soil development and land use changes. PAM, a synthetic compound, has decreased water seepage losses in earthen canals. A new heat pulse probe was designed, refined and evaluated in multiple collaborations to ehance accurate soil water measurements. OUTPUTS: Extensive number and quality of refereed publications remain a hallmark of this multistate project (see publication section). In addition, a special ediction of the Vadose Zone Journal was created and populated with scientific efforts from this project and others. International training programs were conducted on the use, adaptation and applicablility of fate and transport models useful in agricultural and environmental modeling and monitoring programs. ACTIVITIES:New knowledge and partnerships were present as exemplified by multi-institution collaborations on scientific journals, co-creation and use of computer training sessions and models globally, increasing number of visiting scientists and growth of graduate student from other countries. Improved sealing of bentonite liners were established through use of polypropylene fiber amendments which reduce cracking and help to maintain the designed barrier. Collaborative geophysical measurement techniques were developed and tested to map and monitor mine tailings and their landscape-scale impacts. MILESTONES: New measurement devices have been developed, evaluated and compared for their use in characterizing or monitoring solute, compounds and energy transport in highly engineered matices, natural and managed ecosystems. The quality of their data generated coupled with new statistical techniques have bee on-going and are being standardized for uniform applications. Allied disciplines have been a new addition to the annual meeting and subsequent discussions and research collaborations needed to shape and expand the applicability and relevance of the next 5-year project proposal (review mintues and meeting agendas for the last two years, and new project proposal).

Publications

Abdu, H., D. A. Robinson, M. Seyfried, and S. B. Jones. 2008. Geophysical imaging of watershed subsurface patterns and prediction of soil texture and water holding capacity. Water Resour. Res., 44, W00D18, doi:10.1029/2008WR007043. Akay, O., G. A. Fox, and J. `imonek. 2008. Numerical simulation of water flow during macropore/subsurface drain interaction using HYDRUS, Vadose Zone J. 7(3):909-918. Anapalli, S.S., L.R. Ahuja, D.C. Nielsen, T.J. Trout, and L. Ma. 2008. Use of Crop Simulation Models to Evaluate Limited Irrigation Management Options for Corn in Semi-Arid Environment. Water Resour. Res. 44, W00E02. Baumhardt, R.L., O.R. Jones, and R.C. Schwartz. 2008. Long term effects of profile-modifying deep plowing on soil properties and crop yield. Soil Sci. Soc. Am. J. 72:677-682. Berli, M., A. Carminati, T.A. Ghezzehei, and D. Or. 2008. Evolution of unsaturated hydraulic conductivity of aggregated soils due to compressive forces. Water Resour. Res. 44:W00C09. Bradford, S. A., and S. Torkzaban. 2008. Colloid transport and retention in unsaturated porous media: A review of interface, collector, and pore scale processes and models. Vadose Zone J. 7:667-681. Bradford, S. A., E. Segal, W. Zheng, Q. Wang, and S. R. Hutchins. 2008. Reuse of CAFO waterwater on agricultural lands: Potential environmental contaminants, transport pathways, and treatments. J. Environ. Qual. 37:597-615. Buchner, J. S., J. `imonek, J. Lee, D. E. Rolston, J. W. Hopmans, A. P. King, and J. Six. 2008. Evaluation of CO2 fluxes from an agricultural field using a process-based numerical model, J. Hydrology, doi: 10.1016/j.jhydrol.2008.07.035, 361(1-2):131143. Caldwell, T.G., E.V. McDonald and M.H. Young. 2008. The seedbed microclimate and active revegetation of disturbed lands in the Mojave Desert. J. Arid Environs. doi:10.1016/j.jaridenv.2008.12.008 Caldwell, T.G., M.H. Young, J. Zhu and E.V. McDonald. 2008. 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Page, and A.C. Chang. 2008. Fertilizer Application and Trace Element Contents in Vegetable Production Soils of California. Water, Air & Soil Pollution 190:209-219. Chen, W.P., L.S. Wu, W.T. Frankenberger, Jr., and A.C. Chang. 2008. Soil Enzyme Activities of Long-term Reclaimed Wastewater Irrigated Soils. J. Environ. Qual. 37:536-542. Chief, K., T.P.A. Ferré, and A. C. Hinnell. 2008. The effects of anisotropy on in situ air permeability measurements. Vadose Zone J. 7:1-7. Chief, K., T.P.A. Ferré, and B. Nijssen. 2008. Examination of correlation between air permeability and saturated hydraulic conductivity in unburned and burned desert soils. Soil Sci. Soc. Am. J. 72:1-9 Corwin, D. L., and S. A. Bradford. 2008. Environmental Impacts and Sustainability of degraded water reuse. J. Environ Qual. 37:51-57. Das, N.N. B.P. Mohanty, M.H. Cosh, and T.J. Jackson. 2008. Modeling and Assimilation of Root Zone Soil Moisture Using Remote Sensing Observations in Walnut Gulch Watershed During SMEX04. 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International Atomic Energy Agency, Vienna, Austria. ISSN 10185518. Hendrickx, J. M. H., H. Xie, J. B. J. Harrison, B. Borchers, and J. `imonek. 2008. Global Prediction of Thermal Soil Regimes, SPIE. Jacques, D., J. `imonek, D. Mallants, and M. Th. van Genuchten. 2008. Simulation of the effect of time-variable water flow on the speciation and mobility of reactive elements in soil, In: J. `imonek and R. Kodeaová (eds.), Proc. of The Second HYDRUS Workshop, March 28, 2008, ISBN: 978-80-213-1783-3, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 85-92. Jones, S.B., R.M. Estevez and D.A. Robinson. 2008. Frequency-Dependent Permittivity for Soil Water Content Determination. Second Workshop for Applications of Electromagnetic Techniques in Environmental Monitoring. Proceedings of Workshop II, Applications of Electromagnetic Techniques for Environmental Monitoring. August 26-27. Department of Civil Engineering University of Taubate (UNITAU), Brasil. Pontedeiro, E. M., M. Th van Genuchten, R. M. Cotta, and J. `imonek. 2008. The impact of preferential flow on the risk assessment of a radioactive mining waste disposal site, 2nd International Conference on Engineering for Waste Valorisation WasteEng 08, June 3-5, Patras, Greece. Saito, H., M. Sakai, J. `imonek, and N. Toride. 2008. Numerical Analysis of Coupled Water, Vapor, and Heat Transport in Soils using HYDRUS, Proc. Soil Moisture Workshop, Tamachi, Tokyo, Japan, March 26-27, pp. 6. Sakai, M., J. `imonek, and H. Saito. 2008. Evaluating Evapotranspiration from Meteorological Data Using HYDRUS-1D, In: J. `imonek and R. Kodeaová (eds.), Proc. of The Second HYDRUS Workshop, March 28, ISBN: 978-80-213-1783-3, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 93-97. Sakai, M., J. `imonek, and H. Saito. 2008. Evaluating Evapotranspiration from Meteorological Data Using HYDRUS-1D, In: Saito, H., M. Sakai, N. Toride, and J. `imonek, (eds.), Proc. of The Third HYDRUS Workshop, June 28, Dept. of Ecoregion Science, Tokyo University of Agriculture & Technology, Fuchu Tokyo, Japan, ISBN: 978-4-9901192-5-6, pp. 3-14. Sansoulet, J., Y.-M. Cabidoche, P. Cattan, S. Ruy, and J. `imonek. 2008. Spatially distributed water fluxes in an Andisol under banana plants: Experiments and 3D modeling, abstract 246,13th IWRA 13th World Water Congress, Montpellier, France, 1-4 September, pp. 12. Schuh, M.C., and F.X.M. Casey. 2008. Farm-scale Reconnaissance of Estrogens in Subsurface Waters. ND Water Resour. Res. Insti. North Dakota State Univ. Report: ND08-06. Project: 2006ND145B. Period: 3/1/06-2/29/08. `imonek, J., M. `ejna, and M. Th. van Genuchten. 2008. New Features and New Developments in HYDRUS Software Packages, In: J. `imonek and R. Kodeaová (eds.), Proc. of The Second HYDRUS Workshop, March 28, ISBN: 978-80-213-1783-3, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 3-12. `imonek, J., M. `ejna, and M. Th. van Genuchten. 2008. New Features and New Developments in HYDRUS Software Packages, In: Saito, H., M. Sakai, N. Toride, and J. `imonek, (eds.), Proc. of The Third HYDRUS Workshop, June 28, Dept. of Ecoregion Science, Tokyo University of Agriculture & Technology, Fuchu Tokyo, Japan, ISBN: 978-4-9901192-5-6, pp. 3-14. `imonek, J., M. `ejna, H. Saito, M. Sakai, and M. Th. van Genuchten. 2008. The HYDRUS-1D Software Package for Simulating the Movement of Water, Heat, and Multiple Solutes in Variably Saturated Media, Version 4.0, HYDRUS Software Series 3, Department of Environmental Sciences, University of California Riverside, Riverside, California, USA, pp. 315. Twarakavi, N. K. C., and J. `imonek. 2008. A coupled modeling approach for incorporating variably-saturated water flow and solute transport in ground water models, Proceedings of a conference MODFLOW and More, Golden, CO. Twarakavi, N. K. C., J. `imonek, and S. Seo. 2008. A HYDRUS based approach for coupled modeling of vadose zone and ground water flow at different scales, In: J. `imonek and R. Kodeaová (eds.), Proc. of The Second HYDRUS Workshop, March 28, ISBN: 978-80-213-1783-3, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 47-53. Published Abstracts Araújo, J. B., S. A. Bradford, J. Simunek, H. Vereecken, and E. Klumpp. 2008. Transport of metabolically active bacteria in porous media: The effect of substrate, age, and grain size, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract H43C-1022. Berger, P.A., M.S. Meding, M. Tuller, M.G. Schaap, and C. Rasmussen. 2008. Particle Size Analysis with Laser Diffractometry Comparison to Standard Methods. SSSA International Annual Meeting, Houston, TX, October 5-9, 2008. Berger, P.A., R. Heinse, H. Abdu, M. Tuller, S.B. Jones, M.G. Schaap, and J.F. Artiola. 2008.Geophysical Characterization of Inactive Mine Tailings A First Step for Economical Design of Vegetative Covers. AGU Fall Meeting, San Francisco, CA, December 10-19. Berger, P.A., R. Heinse, M. Tuller, S.B. Jones, M.G. Schaap, and J.F. Artiola, 2008. Physical and Hydrological Characterization of Mine Tailings - A First Step for Revegetation with Native Plant Communities. SSSA International Annual Meeting, Houston, TX, October 5-9. Casey, F.X.M., H. Hakk, G. Larsen, T. DeSutter, E. Khan, and P.G. Oduor. 2008. Reproductive Hormones in the Environment. In Annual Meetings Abstracts [CD-ROM]. Joint Annual Meetings of Geol. Soc. Am. Agron. Soc. Am., Crop Sci. Soc. Am., and Soil Sci. Soc. Am., Houston, October 5-9. Casey, F.X.M., T. DeSutter, E. Khan, P. Oduor, H. Hakk, and G.L. Larsen. 2008c. Fate and Transport of Reproductive Hormone. National Science Foundation Poster Session. In Annual Meetings Abstracts [CD-ROM]. Joint Annual Meetings of Geol. Soc. Am. Agron. Soc. Am., Crop Sci. Soc. Am., and Soil Sci. Soc. Am., Houston, October 5-9. Chen Lopez, J.C., P. Waller, G. Giacomelli, and M. Tuller, 2008. Physical Characterization of Greenhouse Substrates for Automated Irrigation Management. ISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, Tucson, AZ, October 20-24. Cheyns, K., J. Mertens, J. `imunek, E. Smolders and D. Springael, Describing pesticide degradation using Monod kinetics: information from batch and column data, The Second HYDRUS Workshop, March 28, 2008, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 12. De Wilde, T., J. Mertens, J. `imonek, K. Sniegowksi, P. Spanoghe, J. Ryckeboer, P. Jaeken, and D. Springael, Evaluating sorption and degradation characteristics of pesticides using column displacement experiments, The Second HYDRUS Workshop, March 28, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 11. Derby, N.E., and F.X.M. Casey. 2008. Occurrence of Hormones in Leachate and Shallow Groundwater Under a Concentrated Swine Feeding Operation. In Annual Meetings Abstracts [CD-ROM]. Joint Annual Meetings of Geol. Soc. Am. Agron. Soc. Am., Crop Soc. Am., and Soil Sci. Soc. Am., Houston, October 5-9. Guber, A.K., M. Tuller, M.A. Martin, F. San Jose Martinez, and Y.A. Pachepsky. 2008. Using X-Ray Computed Tomography Visualizations of Large Soil Columns to Study Hydropedologic Relationships at the Horizon Scale. 1st International Hydropedology Conference, University Park, Pennsylvania, July 28-31. Heinse, R., S.B. Jones, D. Or, M. Tuller, T.S. Topham, I. Podolsky, and G. Bingham, 2008. Challenges of Watering Plants in Space: Water Retention and Distribution What Have We Learned? 37th Committee on Space Research (COSPAR) Scientific Assembly, Montreal, Canada, 13-20 July. Hicks, R. T., D. T. Hamilton, and J. `imonek, Using APIs AMIGO Produced Water Release Decision Tool, 15th annual International Petroleum & BioFuels Environmental Conference (IPEC), Albuquerque, New Mexico, November 11-13. Hopmans, J. G. J. Kluitenberg, J. `imonek, B. Shaw, G. Pasternack, A. Tuli, and T. Kamai, Development of multi-functional heat pulse probe for soil monitoring of natural and managed ecosystems, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 699-22, ASA, Madison, WI. Iassonov, P., and M. Tuller. 2008. Evaluation of Segmentation Techniques for Quantitative Analysis of X-Ray CT Images of Geological Materials. XVII International Conference on Computational Methods in Water Resources (CMWR), San Francisco, CA, July 6-10. Iassonov, P., and M. Tuller. 2008. Recent Advances in Quantitative Image Processing. Synchrotron Environmental Science IV (SESIV) Meeting, San Francisco, CA, December 11-13. Iassonov, P., and M. Tuller. 2008. Segmentation of X-Ray Computed Tomography Images: A Crucial Step for Quantitative Analysis of Porous Structures. SSSA International Annual Meeting, Houston, TX, October 5-9. Jacques, D., J. `imonek, D. Mallants, and M. Th. van Genuchten, Simulation of the effect of time-variable water flow on the speciation and mobility of reactive elements in soil, The Second HYDRUS Workshop, March 28, 2008, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 21. Jones, S.B., M. Tuller, and D. Or. 2008. Liquid Imbibition in Particulate Porous Media in Microgravity. 37th Committee on Space Research (COSPAR) Scientific Assembly, Montreal, Canada, 13-20 July. Kodeaová, R., M. Ko árek, J. Kozák, V. Kodea, J. `imonek, N. Vignozzi, and M. Pagliai, Impact of soil micro-morphological features on character of water flow and solute transport, The Second HYDRUS Workshop, March 28, 2008, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 9. Lazarovic, N., and J. `imonek. 2008. Models for estimating root water uptake, WIMEK-NUPUS-PE&RC Workshop Roots - an interdisciplinary link, September 10 12. WICC, Wageningen, The Netherlands. Martin, M.A., F. San Jose Martinez, F.J. Caniego, M. Tuller, A. Guber, C. Garcia-Gutierrez, and Y. Pachepsky. 2008. Macroporosity of 2-D Cross Sections of Soil Columns via X-ray CT: Multifractal Statistics and Long Range Correlations for Assessing 3-D Soil Pore Structure. XVII International Conference on Computational Methods in Water Resources (CMWR), San Francisco, CA, July 6-10. Matthees, H., D.G. Hopkins, and F.X.M. Casey. 2008. Soil Properties Influencing Restoration of Oil Access Roads in Western North Dakota. In Annual Meetings Abstracts [CD-ROM]. Joint Annual Meetings of Geol. Soc. Am. Agron. Soc. Am., Crop Sci. Soc. Am., and Soil Sci. Soc. Am., Houston, October 5-9. Moreno, H., J. M. H. Hendrickx, H. Xie, and J. `imonek. 2008. Global prediction of thermal regimes in bare soils, SPIE Defense and Security Conference, March. Pachepsky, Ya., A. Guber, M. T. Van Genuchten, J. `imonek, T. Gish, T. J. Nicholson, and R. E. Cady. 2008. Multimodeling and concurrent use of models for flow and transport in vadose zone, NGWA (the National Ground Water Association) 2008 Ground Water Summit, Memphis, Tennessee, March 30 - April 3. Saito, H., M. Sakai, J. `imonek, and N. Toride. 2008. Numerical Analysis of Simultaneous Movement of Water, Vapor and Heat in Soils in Deserts using HYDRUS, Desert Technology 9, Douz, Tunisia, Nov. 13-16. Saito, H., M. Sakai, J. `imonek, N. Toride. 2008. Numerical analysis of one-dimensional coupled water, vapor and heat transport in the unsaturated zone using HYDRUS, Japan Geoscience Union Meeting, Makuhari, May 25-30. Saito, H., N. K. Twarakavi, and J. `imonek. 2008. Characterizing spatial variability of soil hydraulic properties using pedotransfer function and geostatistics, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 577-3, ASA, Madison. Sakai, M, J. Simunek, and H. Saito. 2008. Boundary Conditions at the Soil-Atmosphere Interface from Meteorological Data Using HYDRUS-1D, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract H13A-0872. Sakai, M., J. `imonek, and H. Saito. 2008. Evaluating Evapotranspiration from Meteorological Data Using HYDRUS-1D, The Second HYDRUS Workshop, March 28, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 22. Sakai, M., K. Nakano, J. `imonek, and N. Toride. 2008. Numerical analysis of water flow in root zone using meteorological data, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 783-2, ASA, Madison. Sansoulet J., F. Feder, J. `imonek, V. Bochu, A. Findeling, and E. Doelsch. 2008. Transport of Reactive Anions and Cations in a Volcanic Soil: Experiments and Modelling, ECSSS EUROSOIL 2008, Control No. 2008-A-101-EUROSOIL, Vienna, Austria, August 25-29. Sansoulet, J., Y.-M. Cabidoche, P. Cattan, S. Ruy, and J. `imonek. 2008. Spatially distributed water fluxes in an Andisol under banana plants: Experiments and 3D modeling, abstract 246,13th IWRA World Water Congress, Montpellier, France, 1-4 September. Schuh, M., F.X.M. Casey, and H. Hakk. 2008. Farm-Scale Reconnaissance of Estrogens in Subsurface Waters. In Annual Meetings Abstracts [CD-ROM]. Joint Annual Meetings of Geol. Soc. Am. Agron. Soc. Am., Crop Sci. Soc. Am., and Soil Sci. Soc. Am., Houston, October 5-9. Seshadri, S., R.C. Anderson, M. Schaap, V. Baker, J. Dohm, M. Tuller, K.B. Chin, and M. Buehler. 2008. Detecting Water/Ice in Planetary Regoliths Using Electrical Impedance Spectroscopy. 39th Lunar and Planetary Science Conference (LPSC), League City, Texas, 10-14 March. `imonek, J. and J. W. Hopmans, Compensated water and solute root water uptake, Invited presentation, Proceedings of the XVII. International Conference Computational Methods in Water Resources, July 6-10, San Francisco. `imonek, J., M. `ejna, and M. Th. van Genuchten. 2008. New Features and New Developments in HYDRUS Software Packages, The Second HYDRUS Workshop, March 28, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 6. `imonek, J., M. Th. van Genuchten, and M. `ejna. 2008. Modeling nonequilibrium and preferential flow and transport with HYDRUS, Invited presentation, Geophysical Research Abstracts, Vol. 10, EGU2008-A-01730, SRef-ID: 1607-7962/gra/EGU2008-A-01730, EGU General Assembly. `imonek, J., M. Th. van Genuchten, and M. `ejna 2008. Modeling nonequilibrium and preferential flow and transport with HYDRUS, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 783-3, ASA, Madison. Siripattanakul, S., W. Wirojanagud, J.M. McEvoy, F.X.M. Casey, and E. Khan. 2008. Atrazine Removal in Agricultural Infiltrate by Bioaugmented Polyvinyl Alcohol Immobilized and Free Agrobacterium radiobacter J14a: A Sand Column Study. Chemosphere 74:308-313. Epub Oct 10. Torkzaban, S, S. Bradford, J. Simunek. 2008. Factors Influencing Colloid Transport and Retention in Saturated Porous Media, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract H52A-06 (Invited presentation). Tuller, M., and Th. Gebrenegus, 2008. Polypropylene Fiber Amendments to Alleviate Initiation and Evolution of Dessication Cracks in Bentonite Liners. SSSA International Annual Meeting, Houston, TX, October 5-9. Tuller, M., P. Iassonov, and Th. Gebrenegus. 2008. Advanced Techniques for Segmentation of X-Ray Computed Tomography Images of Geomaterials. AGU Fall Meeting, San Francisco, CA, December 10-19. Twarakavi, N. K. C. and J. Simunek. 2008. A coupled modeling approach for incorporating variably-saturated water flow and solute transport in ground water models, MODFLOW and More: Ground Water and Public Policy, The International Ground-Water Modeling Center (IGWMC), Colorado School of Mines, Golden, Colorado, May 19-21. Twarakavi, N. K. C., and J. `imonek. 2008. A coupled modeling approach for incorporating variably saturated water flow and solute transport in ground water models, Proceedings of the XVII. International Conference Computational Methods in Water Resources, July 6-10, 2008, San Francisco. Twarakavi, N. K. C., J. `imonek, and S. Seo. 2008. A HYDRUS based approach for coupled modeling of vadose zone and ground water flow at different scales, The Second HYDRUS Workshop, March 28, 2008, Dept. of Soil Science and Geology, Czech University of Life Sciences, Prague, Czech Republic, pp. 14. Twarakavi, N. K.C. and J. `imonek. 2008. A coupled approach to modeling vadose zone and ground water flow and solute transport at different scales, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 783-4, ASA, Madison. van Genuchten, M. Th., and J. `imonek. 2008. On the characterization and inverse estimation of the unsaturated soil hydraulic properties, Soil Science Society America annual meeting, Agronomy Abstracts, published on a CD-ROM as abstract 575-9, ASA, Madison. Viola, R., P. Macini, E. Mesini, and M. Tuller, 2008. Non-Darcy Flow: Correlation between Inertial Coefficient and Particle Size Distribution of Unconsolidated Porous Media. SSSA International Annual Meeting, Houston, TX, October 5-9.

Impact Statements

New sensors for mass and energy transport measurements have been evaluated, improved through engineering and statistical efforts and applied to laboratory and field applications. Our ability to construct improved liners from different materials for storage of societal wastes, energy development contaminants, mine tailings, irrigation water transport and tailwater recovery, and so on has been greatly improved.
Multistate collaborations have jointly and indivdually secured tens of millions of external funding support from state and local water, environmental and agricultural agencies to evaluate alternatives and provide science-based alternatives for policymakers to evaluate and implement. In addition, competitive grants have been secured by participants from USDA, DOE, DOD, NSF, NIH, Commerce, EPA and NASA in support of key scientific and societal challenges. In addition, scientists from national laboratories and the USDA ARS are regular and highly regarded collaborators and participants in this project.
Advances in heat pulse technology for soil water flux determination opened new opportunities for agricultural and environmental research and enhanced monitoring capabilities in multiple ecosystems.
Establishment of lysimeter facility in Nevada opened new avenues for climate change and drought research in semi-arid environments. In addition, a shared instrumentation and training facility is now available for applications of W-1188 members at the University of Arizona. This is a highly unique facility and is a direct result of the high level of colloboration of these scientists.
Participants in this project are some of the world‘s leaders in measuring mass and energy transport. International scientists and students have recently been established with Russia, Japan, Korea, Turkey, China, Spain, Brazil, Pakistan, and Jordan.

Date of Annual Report: 11/11/1111

Report Information

Annual Meeting Dates: 01/04/2009 - 01/07/2009
Period the Report Covers: 11/11/1111 - 11/11/1111