Development of ammonia emission factors for the land application of poultry manure in the Lower Fraser Valley of British Columbia

An estimated 6 per cent of all Canadian ammonia emissions can be attributed to land application of poultry manure. Poultry production in British Columbia (BC) constitutes 15 per cent of the total production in Canada, most of it concentrated in the Lower Fraser Valley, generating about 300,000 tonnes of manure each year. The losses of ammonia must be quantified in order to predict local deposition, nitrogen balances and impact on air quality, particularly the formation of secondary fine particulate matter less than 2.5 mm which is often composed of ammonium nitrate and ammonium sulfate. This study investigated ammonia emissions associated with manure application from various types of poultry operations. After manure application, ammonia emission rates were determined using wind tunnels, capturing the emitted ammonia with acid traps. For all trials, the highest emissions occurred within the first day, and gradually declined over the next 2-3 weeks. Cumulative ammonia emission in all treatments did not exceed the initial amount of ammonia nitrogen present in manure. Ammonia emission rates were significantly different among the manure types. The percent total loss of ammonia with time was positively correlated with manure pH. Ammonia emission rates were typically higher in the spring trials than the fall trial. These data will be used to update ammonia emission factors for BC and Canada. 26 refs., 4 tabs., 3 figs