TY - JOUR AU - Hoar, Bruce AU - Atwill, Edward R. AU - Carlton, Lesa AU - Celis, Jorge L. AU - Carabez, Jennifer AU - Nguyen, Tran TI - Buffers between grazing sheep and leafy crops augment food safety JF - California Agriculture JO - Calif Agr Y1 - 2013/04/01 VL - 67 IS - 2 SP - 104 EP - 109 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://dx.doi.org/10.3733/ca.v067n02p104 L3 - 10.3733/ca.v067n02p104 AB - The presence of livestock in or near fresh-market vegetable fields has raised concerns about the potential for contaminating produce with pathogenic bacteria. To develop buffer zones for grazing near production of leafy greens, we assessed the prevalence of Escherichia coli O157:H7 and Salmonella species in sheep that were grazed on alfalfa fields during the winter in California's Imperial Valley. We found E. coli O157:H7 in 1.8% of fecal samples and 0.4% of soil samples, and Salmonella in 0.8% of fecal samples and 0.4% of soil samples. Our results indicate that sheep grazing on alfalfa in the Imperial Valley have a low prevalence of these pathogens in their feces and that these bacteria are rarely found in soil from fields with grazing sheep. The California Leafy Green Products Handler Marketing Agreement guideline of 30 feet between grazing lands or domestic animals and the crop edge is adequate to minimize potential contamination of nearby crops.