Technical Abstract: Ammonia emissions from poultry litter results in air pollution and can cause high levels of ammonia 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, ammonia emissions, and nitrous oxide emissions, and (2) evaluate the effects of various management strategies on ammonia losses in the houses and following land application. Four tunnel-ventilated broiler houses were equipped with ammonia sensors, anemometers, and data-loggers which were used to continuously record ammonia concentrations and ventilation for two years. 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. 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 ammonia/bird. During year 2 the effects of dry and liquid alum were evaluated. Alum treatments significantly reduced ammonia 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, ammonia losses were virtually zero.