Management reduces E. coli in irrigated pasture runoff
California Agriculture 61(4):159-165. DOI: 10.3733/ca.v061n04p159.
Microbial pollutants, some of which can cause illnesses in humans, chronically contaminate many California water bodies. Among numerous sources, runoff from irrigated pastures has been identified as an important regulatory target for improving water quality. This study examined the potential to reduce E. coli contamination from cattle in irrigated pastures. During the 14 irrigation events examined, we found that E. coli concentrations were lowest with a combination of three treatments: filtering runoff through a natural wetland, reducing runoff rates, and letting the pasture rest from grazing at least a week prior to irrigation. Integrated pasture and tailwater management are required to significantly reduce E. coli concentrations in runoff.
A.K. Knox was Graduate Student in Ecology, UC Davis, and now is Ecologist, WSP Environmental Strategies, Seattle, Wash. K.W. Tate is Rangeland Watershed Specialist, Department of Plant Sciences; R.A. Dahlgren is Professor of Soil Science, Department of Land, Air and Water Resources; E.R. Atwill is Cooperative Extension Specialist and Director, Western Institute of Food Safety and Security, School of Veterinary Medicine; all at UC Davis.