Field Scale Soil Nutrient Variability in Beef Cattle Feedlot Operating On Karst Topography.

Movement of soil nutrients from beef cattle feedlot operations can pose environmental risks related to soil and water quality. On karst topography where geomorphic features, like sinkholes, provide passage for contaminants to reach the ground water rapidly, assessment of field scale soil nutrient variability becomes an important aspect in soil nutrient management planning. Understanding field scale soil nutrient spatial variability helps to identify proper site specific best management practices and to implement them effectively to control the soil nutrient movement from source areas. As background information for a long-term study, we assessed soil P, Cu, Zn, and Fe levels across the landscape in a small scale beef cattle feedlot from holding barn and feeder area to the lower retention basin area. We gathered this soil nutrient information as point estimates and scaled them to field level using GIS tools. Soil P, Cu, Zn, and Fe distribution in the feeder/barn area, in the adjacent grass strip area, and in the lowest retention basin area close to a sinkhole will be presented.