Monday, November 5, 2007 - 3:30 PM
121-9
Predicting Ammonia Loss from Manure in Eastern Canada.
Erin Smith1, R. Gordon2, Charles Bourque3, Allan J. Campbell4, and Philippe Rochette4. (1) PO Box 550 20 Tower Road, Nova Scotia, Dept. of Agr. & Mktg., Nova Scotia Agricultural College, Department of Agriculture & Marketing, Truro, NS B2N 5E3, CANADA, (2) Nova Scotia Agricultural College, Truro, NS B2N 5E3, Canada, (3) Forestry and Environmental Management, University of New Brunswick, P.O. Box 4440, Fredericton, NB E3B 5A3, Canada, (4) Agriculture and Agri-Food Canada, 440 University Avenue, Charlottetown, PE C1A 4N6, Canada
The land spreading of manure can result in significant nitrogen (N) losses to the atmosphere through the process of NH3 volatilization. It is estimated that agricultural activities, including the land spreading of manure contribute approximately 50% of the total global emissions. Various models have been developed to aid in predicting NH3 losses after manure spreading. Few have however, been validated with success, and no models have been evaluated under Eastern Canadian conditions. A mechanistic Volt’Air model was implemented and tested to predict NH3 loss after manure application using field wind tunnel data obtained from three locations in Eastern Canada. The model was validated using 27 trials. Good overall agreement was observed between measured results and model simulations. Short-term flux simulations within the first 24 h after spreading, however, were greatly underestimated. Sensitivity analysis revealed that Volt’Air was most sensitive to pH. It appears that this model offers potential for predicting NH3 losses within Eastern Canada , but caution should be practiced with short-term (24 h) fluxes.
Keywords: ammonia volatilization, flux, mechanistic model, pig manure, wind tunnels