2008 Annual Report
The Cove Mountain Creek Watershed in Southern Pennsylvania was instrumented and monitored year-round to provide datasets for validation and improvement of the bacterial transport submodel in the ARS watershed model SWAT. Concentrations of both generic and potentially pathogenic E. coli were measured. Support and participation of local school and watershed community groups were established. The preliminary calibration of the SWAT model was performed.
The Patuxent lysimeter site was re-instrumented to simulate the edge-of-field input of manure-borne E. coli to vegetated buffer strips. A series of runoff experiments on clay loam and sandy loam soils was carried out to evaluate the efficiency of the vegetated filter strips to retain manure-borne E. coli, phosphorus, and manure particulates, and to provide the validation data for the mechanistic sub-model of surface transport of manure-borne coliforms at field scale.
A new laboratory setup was designed and implemented to evaluate the effect of manure particulates on soil water retention and evaporation from soils. A series of experiments has been carried out that has demonstrated that manure application may bring favorable changes to soil evaporative water losses.
A mechanistic sub-model has been developed for the USDA-ARS runoff and erosion model KINEROS to simulate the surface transport of manure-borne coliforms at field scale. Surface release, dispersion in the overland flow, attachment, size exclusion, and straining in soils and vegetation are included as the possible transport mechanisms. The submodel has been verified with the series of experiments at the Patuxent lysimeter site.
With the objective of obtaining experimental data to estimate pathogen transport characteristics, this research is aligned with Research Component "Pathogens and Pharmaceutically Active Compounds (PACs)" of the National Program 206 Action Plan in its Problem Area 2a. “Inactivation Rates and Transport Characteristics of Pathogens from Animal Agriculture.”
2. The effect of manure particulates on soil hydraulic properties. The agronomic importance of manure application is usually attributed to supply of nutrients whereas the effect of manure particulates on soil water balance and availability of water to plants is mostly unknown. The significant effect of manure particulates on soil hydraulic properties was demonstrated in laboratory experiments. Soil water retention decreased, and evaporative soil water losses decreased as manure particulates were introduced in soil. This result poses a new research question whether manure application substantially improves water economy of soils. This accomplishment aligns with the Component IIIg “Modeling Fate and Transport of Manure-borne Pathogens from “Pedon” to Watershed Scale” of the NP 206 “Manure Byproduct and Utilization.”
5.Significant Activities that Support Special Target Populations
Guber, A.K., Gish, T.J., Pachespsky, Y.A., van Genuchten, M., Daughtry, C.S., Nicholson, T.J., Cade, C.S. 2008. Temporal stability of soil water content and soil water flux patterns across agricultural fields. Catena. 73:125-133.
Pachepsky, Y.A., Karns, J.S., Yu, O., Shelton, D.R., Guber, A.K., Van Kessel, J.S. 2008. Strain-dependent variations in attachment of E. coli to soil particles of different sizes. International Agrophysics. 22:61-66.
Pachepsky, Y.A., Gimenez, D., Lilly, A., Nemes, A. 2008. Promises of Hydropedology. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 3(40):19.
Lamorski, K., Pachepsky, Y.A., Slawinski, C., Walczak, R. 2008. Using support vector machines to develop pedotransfer functions for water retention of soils in Poland. Soil Science Society of America Journal. 72:1243-1247.
Rawls, W.J., Nemes, A., Pachepsky, Y.A., Saxton, K.E. 2007. Using the NRCS National Soils Information System (NASIS) to provide soil hydraulic properties for engineering applications. Transactions of the ASABE. 50(5):1715-1718.
Nemes, A., Roberts, R.T., Rawls, W.J., Pachepsky, Y.A., Van Genuchten, M.T. 2007. Software to estimate –33 and –1500 kPa soil water retention using the non-parametric k-Nearest Neighbor technique. Journal of Environmental Modeling and Software. 23:254-255.