2007 Annual Report
A mechanistic model to simulate transport of manure-borne E. coli in variably saturated soil has been developed and partially tested. Surface release, attachment, size exclusion, and straining in soils, the effect of the concurrently release manure particulates and ionic strengths can be analyzed using standard weather data as well as custom data on surface water supply, evaporation and transpiration through the distributed root system. The graphic user interface has been designed and a preliminary agreement on the programming work was reached.
Demonstration of differential attachment of E. coli attachment to soils and soil particles using DNA fingerprinting techniques. Attachment of E. coli to soil particles affects the rate and extent of transport in overland flow and in soil. Using rep PCR, we have shown that the preferential attachment of different E. coli strains to particles of different size classes exists and may be quantified using DNA fingerprinting methods. This result poses a new research question whether DNA fingerprinting can be used to elucidate differences in the attachment to mineral surfaces for pathogenic and non-pathogenic E. coli strains. This accomplishment aligns with the “Pathogens” component of the NP 206 Action Plan in its Specific Focus Area 2e “Modeling Fate and Transport of Manure-borne Pathogens from “Pedon” to Watershed Scale.”
The first dataset on size distribution of manure particles released concurrently with E.coli. Manure particles are known to affect transport and retention of microbial pathogens in soil and in overland flow as they may serve as carriers, abode, and nutritional source for microorganisms. However, nothing is known so far about the amounts and sizes of manure particles released during rainfall. We applied the state-of-the-art laser diffractometry-based size distribution measurement technology to obtain the first dataset on sizes of bovine manure particles released during simulated rainfall. The developed technique can be used for further accumulation of data on suspended manure particulates as a factor of fate and transport of manure-borne microbial pathogens. This accomplishment aligns with the “Pathogens” component of the NP 206 Action Plan in its Specific Focus Area 2e “Modeling Fate and Transport of Manure-borne Pathogens from “Pedon” to Watershed Scale.”
Pachepsky, Y.A., Sadeghi, A.M., Bradford, S.A., Shelton, D.R., Guber, A.K., Dao, T.H. 2006. Transport and fate of manure-borne pathogens: modeling perspective. Agricultural Water Management. Online-(doi:10.1016/j.agwat.2006.06.0l0.)
Pachepsky, Y.A., Devin, B.A., Polyanskaya, L.M., Shelton, D.R., Shein, E.V., Guber, A.K. 2006. The limited entrapment model to simulate the breakthrough of arthrobacter and aquaspirillum in soil columns. International Agrophysics. 20(3):207-218.
Pachepsky, Y.A., San Jose Martinez, F., Rawls, W.J. 2007. Fractional Advective-Dispersive Equation as a Model of Solute Transport in Porous Media. In: Sabatier, J., Agrawal, O., Machado, J., editors. Advances in Fractional Calculus: Theoretical Developments and Applications in Physics and Engineering. Dordrecht, The Netherlands:Springer Verlag. pp. 218-231.
Pachepsky, Y.A., Guber, A.K., Shelton, D.R., Yu, O.T. 2007. Effect of Manure on Fecal Coliform Attachment to Soil and Soil Particles of Different Sizes. Applied and Environmental Microbiology. 73(10):3363-3370.
Devin, B.A., Pachepsky, Y.A., Shein, E.V., Polyanskaia, L.M., Shelton, D.R., Guber, A.K. 2006. Model of Aquaspirillum and Arthrobacter transport in soils. Transactions of the Institute of Ecological Soil Science. 20(3):207-218.
Nemes, A., Rawls, W.J., Pachepsky, Ya. A., van Genuchten, M. Th. 2006. Sensitivity analysis of the nonparametric nearest neighbor technique to estimate soil water retention. Vadose Zone Journal. 5:1222-1235.
Guber, A.K., Karns, J.S., Pachepsky, Y.A., Sadeghi, A.M., Van Kessel, J.S., Dao, T.H. 2007. Comparison of release and transport of manure-borne E. coli and Enterococci under grass buffer conditions. Letters in Applied Microbiology. 44(2):161-167.
Benham, B.L., Baffaut, C., Zeckoski, R.W., Pachepsky, Y.A., Mankin, K.R., Sadeghi, A.M., Brannan, K.M., Soupir, M.L., Habersac, M.J. 2006. Modeling Pathogen Fate and Transport in Watersheds to Support TMDLs. American Society of Agricultural and Biological Engineers. 49(4):987-1002.