Cover crop perks and pitfalls
Cover crops have been described as a Rubik’s Cube. Make one move, and you have another set of options to consider. Here are tips to guide you through those options from Joel Gruver, a Western Illinois University soil scientist.
Cover crops suppress weeds, disease, and nematodes. They improve water infiltration and alleviate subsoil compaction.
Planting legumes as a cover crop can add nitrogen (N), while nonlegume cover crops can reduce nitrate leaching at a lower cost than most other methods. However, captured N is not always available for the next crop.
Better yields occur even in high-yield environments. Gruver refers to a 2005 Maryland study in which a cover crop of radishes and radishes and rye boosted soybean yields by 6 bushels an acre.
“If you can feed your cover crop to livestock, you can make it pay,” Gruver says. “Grazing is the number one way cover crops pay.”
Cover crops can tie up N, host pests, become weeds, and suppress crop growth. Remember, too, cover crops have input costs like seed, inoculants, herbicides, and fertilizer. You’ll need to budget for operational costs like cover establishment and termination.
Bank on indirect costs, such as slow soil warming, that affect the following crop. Consider opportunity costs that include foregone income when cover crops replace a cash crop.
“Remember that cover crops require more management than broadly applied off-the-shelf technologies,” he says.
On balance, though, Gruver sees the benefits outweighing the drawbacks.
“If you are a novice, check out the cost-share programs through USDA’s Environmental Quality Incentives Program and Conservation Stewardship Program,” he says. “They are targeted to people who are just getting started, and the amount of money available in many cases will cover the full cost of seed and planting for a limited time trial.”
Gruver also recommends talking to cover crop innovators. “Seed vendors are probably the most networked with innovators and can often help if another farmer is looking for contacts,” he says.
Editor's note: Edith Munro is a freelance contributor for Successful Farming magazine.