Old Rotation Study – Swift Current, Saskatchewan

The “Old Rotation” experiment was initiated in 1966 at the Agriculture and Agri-Food Canada Research Centre at Swift Current, Saskatchewan. The overall objectives were to evaluate the influence of rotation length, fallow substitute crops, and nitrogen (N) and phosphorus (P) fertilizers on crop yields, grain protein, N and P uptake, moisture conservation, nutrient use efficiency, incidence of disease, and long-term changes in soil chemical, physical, and biological properties. Economic returns and non-renewable energy use efficiency from changes in the rotations were also determined. Results to date indicate that increased cropping frequency in combination with appropriate fertilizer applications resulted in the highest total annualized grain production, fostered improvements in soil quality and precipitation use efficiency, and reduced the risk of nitrate-nitrogen leaching. This long-term data set has proven invaluable for developing and testing simulation models used to represent crop growth, soil organic carbon and nitrogen dynamics, soil water and temperature status.