Optimal Rotations with Considerations for Corn in Southern Manitoba

An effective way of assessing the potential of any crop is to estimate the profitability growing it in a single year, but this ignores the impacts of previous crops. The top five crops by seeded area in southern Manitoba are canola, soybeans, spring wheat, grain corn and oats. The yearly return from these crops grown in various five year rotations is the focus of this study. This study uses 5 year average relative yield response values, a measure of the impact that one crop has on the yield of next seeded crop. Rotation options from the 5 top crops are analyzed. Returns using 5 year average yields and prices, adjusted by the estimated impacts of previous crops, are calculated and ranked to determine the top 10 performing rotations. Historical prices were applied to the top ten budgets to see if the rotation ranks survived over time as prices varied. The top rotation, corn and soybeans, remained optimal for all but 3 years in the 13 examined. Continuous cropping, even with high earning corn, is significantly less profitable than crops grown in rotation. Acknowledgement : Funding: This work is part of a multidisciplinary corn rotation project at the University of Manitoba sponsored by the Manitoba Corn Growers and Western Grain Research Fund.