Bacteria Release and Transport from Livestock Manure Applied to Pastureland
American Society of Agricultural and Biological Engineers , 2003
Soupir, M.L., Mostaghimi, S., Alphin, E.F.
A comparative field investigation was conducted on release and transport of bacteria from plots treated with cowpies, turkey litter, and liquid dairy manure. Rainfall conditions were simulated and runoff samples were collected to determine concentrations of E. coli, FC, and enterococcus present in runoff. The turkey treatment had the highest percentage of source bacteria released by rainfall, ranging from 1.3% for enterococcus to 14.5% for FC. The cowpie follows with percentages ranging from 0.3 to 0.6%. Runoff samples collected from the transport plots treated with cowpies averaged 137,000 cfu/100 ml for E. coli and over 165,000 cfu/100 ml for FC during two rainfall simulations. Bacteria concentration in runoff from plots treated with liquid dairy manure decreased between the two simulations, while the bacteria concentration from the plots treated with turkey litter increased. The percent of the bacteria that is initially released by rainfall that is transported to the edge of the field in overland flow was highest for the cowpie treatment (95 to 121%), followed by the turkey (41 to 138 %) and liquid dairy treatments (32 to 86%). Results indicated that among the animal waste types investigated, cowpies have the greatest potential to contributed E. coli, FC, and enterococcus to streams and waterways.