Estimation of Canadian manure and fertilizer nitrogen application rates at the crop and soil-landscape polygon level

Abstract

In support of national environmental and economic modeling of agri-environmental indicators, greenhouse gases, carbon sequestration and policy assessment, fertilizer and manure nitrogen application rates were estimated for individual crops at the scale of the 1:1 m Soil Landscapes of Canada polygons. This data base provides an estimate of the amount of nitrogen applied to each crop and is based on provincial fertilization recommendations, the type and number of livestock and manure produced and reported amounts of fertilizer sold. The data base is being incorporated into ongoing programs related to international reporting, environmental performance and policy formulation at Agriculture and Agri-Food Canada. This paper describes the procedures developed to estimate fertilizer and manure nitrogen inputs for each crop type within each polygon. These procedures include:(i) the compilation of soil-specific recommended nitrogen application rates from provincial extension guidelines and experts; (ii) the calculation of total manure nitrogen production from animal numbers and excretion rates; (iii) the calculation of manure nitrogen available after land application losses and (iv) the adjustment of total fertilizer nitrogen applied to match reported sales at the provincial level. The calculation procedures were incorporated into the Canadian Agricultural Nitrogen Budget model, with provisions for transferring the data to other models and for other applications.