Assessing Nutrient Content of Crops and Nutrient Removal as Affected by Management Practices

Current information on the nutrient removal from western Canadian soils using existing and proposed cropping systems is limited. Long-term nutrient depletion could have important negative impacts on soil productivity and long-term sustainability. Changes in farming practices over the past decade have influenced both yield potential and nutrient cycling, so past information on nutrient removal may not reflect the current situation. A study was initiated to identify mineral nutrient removal in the harvested portion of crops, to determine the impact of management practices on nutritional value and nutrient removal, and to identify management practices that can be used to optimize economic yield, functional food quality, and nutrient content of crops grown in western Canada.

Currently, grain samples are being evaluated from a number of long- and short-term management studies in Manitoba and Saskatchewan. These include flax and wheat samples from alternative input studies and wheat and canola samples from a phosphorus (P) fertility and tillage study. Canola seed nitrogen (N) concentration was not influenced by tillage or P rate, while grain N in wheat was reduced slightly by application of P, possibly due to dilution with increasing grain yield. Phosphorus concentration in both canola seed and wheat grain was increased by P application. Canola seed concentration of P was higher under no-till (NT) than conventional tillage at one of the trial locations, likely because seed yield was reduced by NT. Understanding the impact of nutrient management on food quality will continue to become an important consideration of best management practices. MB-14