Nutrient run-off following application of livestock wastes to grassland.

Three types of farm waste (cattle slurry, dirty water and farm yard manure (FYM)) were applied to hydrologically isolated grassland plots on a sloping poorly draining soil. Two applications were made, the first in October and the second in February. Application rates were 50 m(3) ha(-1) of slurry and dirty water and 50 t ha(-1) of FYM. Volumes of run-off following rainfall events and concentrations of N, P and K in run-off were measured. Losses of nutrients were higher following applications made with the soil at field capacity and rainfall soon after application. In terms of percentage loss of applied nutrients, losses were generally low. Concentration of N in run-off from the dirty water and FYM treated plots following the first application and the slurry treated plots following the second application exceeded 11.3 mg dm(-3) (a recommended limit for drinking water) although the maximum concentration recorded was 15 mg dm(-3) following FYM application. Concentration of P in run-off only exceeded 1 mg dm(-3) following the second application of cattle slurry. Concentration of K exceeded 10 mg dm(-3) following the first application of FYM and the second application of cattle slurry.