Nutrient losses in field-scale surface runoff from claypan soil receiving turkey litter and fertilizer

Information is lacking on nutrient runoff losses from poultry wastes and commercial fertilizers from claypan soils such as those found in southeastern Kansas. The objectives of this study were: (i) to compare field-scale surface runoff losses of nutrients from turkey (Melleagris gallopavo) litter manure and fertilizer and (ii) to compare the influence of tillage incorporation of turkey litter with no tillage on nutrient losses in surface runoff. The experiment was conducted from 2005 through spring 2008 near Girard, KS. The soil was a low-slope Parsons silt loam overlying a claypan B horizon. A high litter rate (N-based) resulted in high flow-weighted concentrations of N and P in runoff, and also resulted in carry-over P losses. N losses were inorganic and organic, whereas P losses were mainly the soluble, ortho-P form partially influenced by low sediment losses. Nutrient losses from fertilizer-only applications were usually lower than from N-based and similar to P-based turkey litter applications. Incorporation appeared to reduce nutrient losses in runoff, but was not always significant. A high litter rate built up soil P levels, and annual P runoff losses appeared to accelerate when soil P values exceeded 30 mg kg−1 in a 0–15 cm sample.