Evaluation of Ammonia Emissions from Broiler Litter

Abstract

Ammonia (NH3) emissions from poultry litter results in air pollution and can cause high levels of NH3 in poultry houses, which negatively impacts bird performance. The objectives of this study were to: (1) conduct a nitrogen (N) mass balance in broiler houses by measuring the N inputs (bedding, chicks, and feed) and N outputs (birds marketed, mortality, litter/cake, NH3 emissions, and nitrous oxide (N2O) emissions, and (2) evaluate the effects of various management strategies on NH3 losses in the houses and following land application. Four tunnel-ventilated broiler houses were equipped with NH3 sensors, anemometers, and data-loggers which were used to continuously record NH3 concentrations and ventilation for two years. Nitrogen inputs from bedding, chicks and feed were 0.60, 1.19, and 139.56 g N/bird, respectively, while outputs for marketed birds, mortality, NH3 emissions, N2O emissions and litter/cake were 78.2, 1.3, 30.8, 0.5, and 28.7 g N/bird. Percent N recovery in the mass balance was equal to 98.6%. Ammonia emissions from litter in the house were 37.4 g NH3/bird, which corresponds to 14.5 g/kg bird marketed (50 day old birds). Emissions during storage and after land application were equal to 0.17 and 7.91 g NH3/bird, respectively. The total NH3 emission factor was 45.5 g NH3/bird. During year 2, the effects of dry and liquid alum were evaluated. Alum treatments significantly reduced NH3 concentrations and emissions. Ammonia losses from poultry litter following land application when litter was broadcast applied to pastures totaled 34 kg N/ha (15% of total N applied), however, when litter was incorporated using a knifing technique, NH3 losses were virtually zero.