Click on “Download PDF” for the PDF version or on the title for the HTML version. If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options. Attachment of bacterial indicators to particulates in runoff from various soilsPublished by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org Citation: 21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings, 29 March - 3 April 2008, Concepcion, Chile 701P0208cd.(doi:10.13031/2013.24295)Authors: Michelle L Soupir, Saied Mostaghimi Keywords: Bacterial partitioning, indicator organisms, E coli, enterococci, nonpoint source pollution Association of E. coli and enterococci with particulates present in runoff from highly erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial transport. A field study was conducted to examine the fate of E. coli and enterococci transport from three bare soil types receiving cowpat treatments. Soil boxes (100-cm 20-cm 7.5-cm) were packed with loamy fine sand, silty loam and silty clay loam soils to simulate runoff from poorly managed erosive soils. A rainfall simulation was conducted 24-hours after application of a standard cowpat, followed by a second rainfall simulation approximately 80 days later. Runoff samples were analyzed for E. coli, enterococci, TSS, phosphorous, organic phosphorous and organic carbon. E. coli and enterococci partitioning coefficient (PC) and particulate associated fraction (PAF) were calculated to compare fecal indicator attachment in runoff from the different soil types and between two pathogen indicators, E. coli and enterococci. Partitioning varied by indicator and by soil type. In general, enterococci had a higher percent attached to the silty loam (49%) and silty clay loam (43%) soils while E. coli had a higher percent attached to the loamy fine sand soils (43%). Findings from this study suggest that high concentrations of total suspended solids in runoff leads to higher bacterial attachment than previously reported. (Download PDF) (Export to EndNotes)
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