Ontario’s extremely dry 2016 growing conditions provided ample evidence of the benefits of growing cover crops and lengthening rotation to improve soil health and moisture-holding capacity.
University of Guelph soil scientist Dr. Bill Deen shared some of that proof with agronomists attending the recent Ontario Certified Crop Advisor Association conference in London. For example, at the Elora Research Station in 2016, Deen noted significantly higher yields in long-term extended rotations that included wheat and other crops compared to strict corn-soy rotations. In some cases corn yields showed a 60-bushel difference.
For Deen, the dry conditions highlighted the ability of extended rotations and cover crops to reduce variability during extreme weather events. He says diversity is the key to drought-proofing soils, but how can farmers improve soil moisture-holding capacity if they are committed to strict corn-soy rotations?
In this interview, Deen discusses the challenges of planting cover crops after corn and soybeans and options for more consistent establishment. He offers insights on the benefits of allowing cover crops to overwinter as well as the challenges “planting green” into cover crops can present. He also gives his assessment of whether growers should consider planting cover crops interseeded post wheat; interseeded post silage; preleaf-drop and post soy harvest; and interseeded into corn.