Characterizing Agricultural Residue Nutrient Properties and Removal Variation in Ontario
Due to recent climate change and energy consumption concerns, several markets have emerged for agricultural biomass in the province of Ontario, Canada. Understanding variation of residue nutrient concentrations across the province and the causal factors is crucial for determining the feasibility of crop residue use in Ontario. The purpose of this study was to survey variation of Ontario winter wheat, soybean and corn residue nutrient concentrations and removals, as well as to determine the effect of altering cutting height and delaying harvest on the nutrient concentrations and removals of these residues. It was found that across-site nutrient concentration and removal variation were greater than within-site concentration and removal variation, and that site-scale climatological events, such as precipitation, are largely responsible. Concentration and removals differed significantly by year. Variation of nutrient concentration and removal did not correlate with crop grain yield, or soil characteristics such as organic matter, pH or texture. A leaching treatment significantly reduced residue nutrient concentrations and removals, but had no significant effect on the variation among residue samples. Finally, concentrations and removals differed significantly with cutting height and harvested corn component, highlighting the importance of harvest method in the system nutrient balances.