Fall-seeded cover crops after dry bean and potato in Southern Alberta

Abstract

Dry bean (Phaseolus vulgaris L.) and potato (Solanum tuberosum L.) usually provide insufficient plant residue cover after harvest to protect the soil from wind erosion. Experiments were conducted at the Lethbridge Research Centre to determine the potential beneficial effects of planting cereal cover crops after Russett Burbank potato, which is harvested in late September or October, and dry bean, which is harvested in mid- to late September at Lethbridge, Alberta. Annual cereals planted after potato provided insufficient ground cover to protect the soil from erosion in the fall or spring. Winter annual cereals after potato and dry bean and annual cereals after dry bean usually provided enough residue in the spring (> 30% ground cover). However, winter cereals killed with glyphosate just before seeding spring wheat (Triticum aestivum L.) consistently reduced wheat yield. Reductions in available N and soil moisture due to winter annual cereals were small, and likely did not reduce wheat yield. None of the cover crops provided enough ground cover to reduce weed density. Additional research is required to assess the benefits of seeding annual cereals after early-maturing potato varieties and after dry bean, which matures earlier at lower elevations in southern Alberta, with more heat units. Key words: Fall rye, ground cover, soil erosion, winter triticale