Quantifying and Controlling Ammonia Losses from Broiler Manure.

Ammonia (NH₃) volatilization from poultry manure greatly reduces the agronomic value of this resource. 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 state-of-art tunnel-ventilated broiler houses were equipped with NH₃ sensors, anemometers, and data-loggers which were used to continuously record NH₃ emissions for two years. The recovery of the N mass balance was 98.6%. Nitrogen inputs were 0.60, 1.19, and 139.56 g N/bird from bedding, chicks and feed, respectively, while outputs were 78.2, 1.3, 30.8, 0.5, and 28.7 g N/bird for marketed birds, mortality, ammonia emissions, nitrous oxide emissions and litter/cake. These data indicate that a larger amount of N was lost as NH₃ via volatilization than the amount retained in the manure. Ammonia emissions from litter in the house were 37.4 g NH₃/bird. 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 ammonia/bird. During the second year of the study the effects of dry and liquid alum were evaluated; both significantly reduced NH₃ concentrations and emissions. Ammonia volatilization from litter following land application totaled 34 kg N/ha (15% of total N applied) when litter was broadcast applied to pastures, however, when litter was incorporated using a knifing technique, NH₃ losses were virtually zero.