Ammonia Volatilization and Crop Yield As a Function of Poultry Litter Application Method.

Continuing concerns on the environmental impacts of agricultural activities have recently focused on determining ammonia emissions and its role in the acidification and eutrophication of water bodies.  Ammonia (NH₃) is the primary neutralizing agent for atmospheric aerosols such as ammonium sulfate and ammonium nitrate. These compounds are precursors of acid rain, and when added to the soil or waterbodies in rain to the soil are rapidly oxidized to nitric and sulfuric acid. In this context, a number of factors may contribute to ammonia volatilization from poultry litter application, including the method of application. The objective of this study was to quantify ammonia losses in the field as a function of method of poultry litter application.  Poultry litter was broadcast on the surface, incorporated and injected on a silt loam soil under corn in Center-West Brazil.  Ammonia losses were greater with surface applied than incorporated or injected litter, compared with the control. The method of application of poultry litter, where it is completely covered after application (injected) without any contact to air reduces the losses of N through ammonia volatilization from the system and increases the productivity of maize and grass.  This represents a more efficient management practice when applying poultry litter in terms of N-use efficiency and loss of N to the environment.