The Ongoing Evolution of Cropping Systems in the Semi-Arid Canadian Prairies.

The Canadian Prairie region has only been growing cultivated crops for 125 years yet the crop production changes during that time are among the greatest in the world. Small grain cereals and fallow dominated the prairie landscape and there was a heavy reliance on tillage in the early years. However, the crop failure and soil erosion events of the 1930s highlighted that those agronomic practices were not sustainable. The earliest efforts on improved farming practices occurred around non-inversion tillage and fallow. Development of the Nobel blade in southern Alberta and widespread adoption of strip cropping were major advances that reduced soil erosion yet cereals remained the dominant crops and periodic erosion events still occurred. Subsequent decades-long research on no-till systems and viable production of oilseed/pulse crops set the stage for the cropping revolution that has occurred in the last 25 years. No-till is now practiced on 75% of cropland and fallow has been reduced 90%. Cereals are still important crops grown on 15 million ha but oilseeds and pulses now occupy 12 and 3 million ha, respectively. Soil erosion is nearly a thing of the past, soil quality is improving, and greater crop diversity has contributed to lower weed and pest incidence. Farmers now routinely grow 4-7 crops annually in diverse rotations as a means of reducing production risk and enhancing market opportunities. Cropping systems are now much more sustainable than in the past but further improvements will be required to meet future demands for greater and healthier food production while simultaneously protecting the environment.