Nutrient losses in surface and subsurface flow from pasture applied poultry litter and composted poultry litter

Abstract

Over application of poultry litter may cause pollution of surface and ground water. Spatial variability in soil characteristics makes predictions difficult. Composting poultry litter could reduce the risk of pollution by creating more stable organic components. Three rates of poultry litter and compost (10 Mg ha-1 litter, 20 Mg ha-1 litter and 10 Mg ha-1 litter combined with 50 Mg ha-1 compost) to three watersheds under pasture. The watersheds were monitored for surface and subsurface flow. Nitrate-N concentrations in subsurface flow did not exceed the U.S. Environmental Protection Agency drinking water standard of 10 mg L-1. Soluble phosphorus concentrations in runoff were high, reaching a maximum of 8.5 mg L-1 under the compost treatment. These concentrations are generally lower than reported on smaller scale studies, which shows the need of studies at the correct scale.