Cover crops, also referred to as polycrops or cocktail crops, are receiving a lot of media hype for their potential for grazing and claims related to reduced inputs and improved soil health. Jillian Bainard, PhD, has been studying cover crop parameters like productivity, soil health, grazing nutrition, and weed control, through her research at Agriculture and Agri-Food Canada in Swift Current, SK. “A lot of people are trying cover crops so we want to understand from a research perspective what’s happening, and whether we can pinpoint some of these benefits that have been suggested,” Bainard explained during a recent webinar presentation.
Cover crops can address many problems, however they require thought and planning to optimize their potential.
Producers often look to cover crops to improve productivity. Bainard’s research demonstrated that some cover crop mixes had greater production compared to single-species crops (ie. monocultures) even under stressful conditions. Different functional groups, such as cool-season grasses, warm-season grasses, legumes, or brassicas, also had a positive effect on production; as the number of groups in a mix increased, production did as well. Bainard did caution that extreme moisture fluctuations will impact plant growth accordingly and that real-world field variables may reduce productivity. For example, a cover crop mix may yield well on lowland areas yet perform poorly on uplands within the same field. “Not all mixtures will perform the same, and success will depend a lot on how well each crop does in a specific soil and environment,” Bainard added.
Lowland and upland performance of same cover crop mixture. Photo credit Charlotte Ward, Saskatchewan Agriculture