Legume Cover Crops in Dryland no-till Cropping Systems.
Martin Entz1, Guy LaFond2, William May3, and Sumithira Nagulswaren1. (1) University of Manitoba, Winnipeg, MB R3T 2N2, Canada, (2) Indian Head Research Farm, Box 760, Indian Head, SK S0G 2K0, Canada, (3) Indianhead Agri Research, PO Box 156, Indian Head, SK S0G 2K0, Canada
Dryland farmers in the Canadian prairie region are concerned with high N fertilizer costs. In wetter growing regions such as Ontario and the NE USA, farmers sometimes use legume cover crops to supplement soil N from biological sources. Few dryland farmers have considered using there techniques. However, the move to no-till cropping may offer an opportunity to grow legume cover crops outside the main growing season since no-till soils often contain more water during spring and autumn. This research was aimed at testing the agronomic benefits of several legume cover crop systems: 1) self-regenerating medics in grain-based systems; 2) various small-seeded forage legumes in winter wheat systems; 3) various small-seeded forage legumes in canola systems. Self-regenerating medics increased soil N supplying power after 5 years in continuous no-till wheat-oat-flax rotations located in Saskatchewan and Manitoba. Spring seeded legumes with winter wheat resulted in a fertilizer N replacement value in a following oat crop of between 0 and 75 kg/ha. Establishment success and failure of small-seeded legumes in winter wheat and canola systems will be discussed.