Ontario Grain Farmer March 2021

Cover story 6 WHEN SOIL MANAGEMENT specialist Anne Verhallen thinks of agronomy, she thinks of the Ontario Ministry of Agriculture, Food and Rural Affairs’ (OMAFRA’s) Agronomy Guide for Field Crops. It’s a comprehensive resource with specific seeding, tillage, fertility, pest management, and harvest recommendations based on more than 100 years of research. But when it comes to cover crops, limited agronomic recommendations are available because long-term agronomic research does not exist. Although cover crop species have been studied for many years, research has primarily been focused on determining and proving environmental benefits. As practice adoption continues to increase, the need for more agronomic information is also growing. “If you’re going to invest time, effort, equipment, and money, it’s time to get serious about growing cover crops,” says Verhallen. “We don’t have all of the agronomy research done — and we won’t for a while — but we do know that many of these crops behave very much like cash crops. This means we can apply the basics of field crop agronomy and use existing tools to improve management.” At the recent Ontario Agricultural Conference, Verhallen collaborated with other OMAFRA specialists, University of Guelph researchers, and farmers who were early adopters of cover crops to share experience-based recommendations during the Cover Crop Agronomy session. STEP 1: SET A GOAL(S) Laura Van Eerd, professor of sustainable soil management at the University of Guelph, says all cover crop practices should begin with setting goals. She cites wind erosion, waterway protection, weed control, and building soil carbon as examples of such objectives. The Midwest Cover Crop Council’s online decision tool (mccc.msu.edu/covercroptool) prompts users to select up to three goals before displaying recommendations. The goals listed range from interseeding with a cash crop and nitrogen growth to lasting residue and good grazing. STEP 2: CHOOSE A COVER CROP(S) Once goals have been established, farmers should select cover crop species that best fit their needs and are suitable to their location. The decision tool provides an updated list of crop recommendations by county and includes recommended planting dates. “Spring cereals like barley or oats are almost a no-brainer because they are inexpensive, we see fast establishment, they have a great root system, and we can feed them,” says Verhallen, who saw faster out-of-the-ground growth in barley compared to oats in trials last summer. When it comes to winter cereals, OMAFRA cereals specialist Joanna Follings says winter wheat is often used to improve soil health, alleviate compaction issues, and provide cover for the entire winter. Winter triticale is similar to winter wheat in hardiness but has good early season vigour and provides quick coverage. When farmers are looking for more weed suppression, allelopathic qualities, or hardiness, Follings points to winter rye. It is often recommended to farmers who want a forage crop that they can graze livestock on or use to create baleage. University of Guelph research has also shown that winter rye can reduce populations of glyphosate- resistant Canada fleabane. “Another cereal crop that is making a bit of a comeback in Ontario is winter barley,” says Follings. But winter barley is not as winter hardy as wheat or rye so it needs to be planted at least seven to 10 days before the optimal winter wheat planting date. Barley also requires an increased seeding rate because when planted late, it cannot manipulate tillers the same way winter wheat can. “Radish and other brassicas are good additions to our cover crop toolbox,” says Verhallen. These crops, including kale, mustard, and turnip, are fast growing, Cover crops AGRONOMY BASICS FOR BETTER MANAGEMENT Rebecca Hannam continued on page 8 • All cover crop practices should begin with setting goals. • Once goals have been established, farmers should select cover crop species that best fit their needs and are suitable to their location. • Understand the benefits of drilling for cover crop establishment. • Farmers should terminate a cover crop the way that works best for them and seek advice from neighbouring farmers with the same soil type. • Look for more information on cover crops in our April/May magazine with a focus on long-term research trials. WHAT YOU NEED TO KNOW