Effects of Poultry Litter Injection On Nitrogen and Phosphorus Movement.

Poultry litter is a valuable source of nutrients in agricultural production systems and is typically applied to the soil surface or incorporated through tillage. However, no-till and forage systems are not compatible with incorporation of poultry litter through tillage, and traditional surface application leaves nutrients vulnerable to loss at the soil surface. Poultry litter injection incorporates manure with minimal soil disturbance. Manure injection has shown potential to decrease losses of nitrogen (N) and phosphorus (P) through reductions in ammonia volatilization and nutrients in runoff. While liquid manure injection is well researched, there is limited information on the impacts of injecting dry poultry litter on N and P movement. It was hypothesized that poultry litter injection would decrease N and P losses, subsequently increasing total inorganic N found in soil. We compared poultry litter injection to surface application in a) a soil incubation to determine differences in extractable soil ammonium and nitrate, b) rainfall simulations to determine total and soluble N and P losses in runoff, and c) an ammonia volatilization study using a closed chamber system to determine differences in ammonia loss. The results of these experiments will be discussed. Poultry litter injection could be a valuable tool for reducing nutrient losses from agricultural fields and increasing plant available N, when compared to traditional surface application.