Philip Moore Jr., USDA-ARS, PPPSRU, 1837 Overcrest St., Fayetteville, AR 72703-3030, Dana M. Miles, Genetics & Precision Ag Research Unit, USDA-ARS, 810 Hwy 12 East, MS State, MS 39762, R.T. Burns, Dept of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, and Dan Pote, USDA-ARS Southern Plains Area, Dale Bumpers Small Farms Research Center, 6883 S. State Hwy. 23, Booneville, AR 72927-9214.
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.