Ammonia emission from dairy cow manure stored in a lagoon over summer

Abstract

It is recognized that volatilized ammonia (NH 3 ) from intensive livestock production can be a significant pathway for nitrogen (N) pollution to land and water, and can contribute to poor air quality. The objectives of our study were to document NH 3 emissions from a dairy lagoon and to assess the influence of meteorology on NH 3 emissions. Ammonia emissions were determined using a backward Lagrangian Stochastic approach using WindTrax software, an open-path NH 3 laser and a sonic anemometer. Results indicate that an average 5.1 ± 1.6 g NH 3 m -2 d -1 was released over the summer; however, the emission varied typically over 24 h between 3.6 and 8.6 g NH 3 m -2 d -1 . Wind speed and surface temperature of the lagoon had similar influences on the magnitude of the release, where their direct impact on NH 3 emission accounted for 28 and 31% of the variability, respectively. The main implication of this study is that NH 3 losses are significant from dairy lagoons, contributing to the issue of N pollution. As well, NH 3 emissions are a loss of valuable N for manure used as fertilizer, which in our study amounted to approximately 13% of the total ammoniacal N content of the manure in the lagoon. Key words: Ammonia, dairy, manure, cattle, dispersion model