Conservation Tillage to Reduce Nutrient Losses From Surface Applied Poultry Litter On the Delmarva Peninsula.

The production benefits of no-till are well known. However, when poultry litter is surface broadcast in no-till systems nutrient losses can be significant due to incidental transfer of nitrogen and phosphorus in runoff. This study was conducted to determine whether conservation tillage could be used to partially incorporate poultry litter in order to reduce nutrient losses in runoff, while maintaining some of the production benefits associated with no-till. No-till, vertical till, strip till, and chisel-disc were evaluated in a continuous corn system for three years on Maryland’s Eastern Shore. Poultry litter was applied each year at a nitrogen based rate. Corn grain yield, residue cover, soil nitrogen and phosphorus concentrations, and total nitrogen, phosphorus, and sediments in runoff were monitored over three growing seasons (2006-2008). In the first year, yields in no till and vertical till were lower than in strip till and chisel disc. Residue cover was preserved with no till, vertical till, and strip till compared to chisel disc. There were no differences in phosphorus and sediment runoff between tillage practices. Strip-till and chisel disc reduced nitrogen losses in runoff relative to no till and vertical till, indicating that partial incorporation of poultry litter by strip till or chisel disc after surface application can reduce nutrient losses on the Delmarva Peninsula.