Dan Towery, Ag Conservation Solutions, Lafayette, Ind., has spent his career working with farmers on conservation. He says farmers with no-till and cover crop systems managed at a high level are growing 220-bushel yields using only 100 to 140 pounds of nitrogen per acre. Here’s his take on ROI with cover crops and no-till.
- Farmers who see notably lower input costs and higher yields use no-till and cover crops as part of a sophisticated management system. The system may include practices such as aerial- or high-clearance seeding of cover crops before harvest to extend soil biological activity, letting covers grow longer in the spring in the right conditions, and adding wheat to the crop rotation so a “warm-season cocktail mix” of cover crop plants can grow. The cocktail is heavy on warm-season legumes that fix nitrogen, build soil filtration, boost organic matter and help suppress weeds. This midsummer seeding allows for extended growth “and that makes a huge difference in your soil biology,” says Towery.
- If you’re just starting, don’t expect instant success, but you could be pleasantly surprised. It takes up to five years to learn how covers work best on your soils and for soil properties to change before you may see changes in yield, weed pressure, fertilizer or soil health. “One of the challenges is if you do cover crops in one field, it’s hard to make a fair comparison in terms of yield bump or yield decrease,” Towery says. “So having some strips in the same field is the only way to tell.”
- Generally you’ll see a quicker yield response (often in first year) on lower-organic-matter soils. All soils are different, and proper management must be learned. There is no one system to follow. Planting no-till soybeans into cereal rye is the best place to start.
- Don’t expect to cut fertilizer costs much, if any, in the first four years of using cover crops. And you will need popup or starter to ensure N is tied up early in the season. After time, improvement in soil organic matter and soil biology will make N, P and K more readily available to the plant, resulting in potentially lower fertilizer rates.
- Farmers who successfully developed their no-till and cover crop system over several years are seeing lower weed pressure and weed control costs. “They’re probably still spending less money on herbicides than conventional, even with a residual and burndown,” says Towery. “Because we’re not stirring up the soil and bringing up weed seeds that were buried a few years earlier.”
- In Towery’s experience, weed control costs may be cut $12 to $18 per acre by planting no-till soybeans into cereal rye. “You spray a residual, a burndown, and that’s it,” he says. “I’ve had guys who put on post-applications, but they didn’t need to, because most of the time fewer weeds germinate in that situation. So you save not just the cost of the trip over the field, but also the cost of the product.”
- If you’re planting covers after harvest and terminating them early in the growing season, you’re reducing potential benefits. The more time covers have to grow, the more soil biological activity you will see. “The guys who are more intense with their management are reaping the most rewards,” says Towery. “It may take four years, plus a higher level of management, but I have seen those guys with mature cover crop systems see higher crop yields and reduced fertilizer costs of $80 to $100 an acre.”
- Over time, cover crops will help build soil water-holding capacity. That’s important if you believe weather extremes (gully washers) have become more common today than, say, 10 years ago. “After four or more years of cover crops and no-till, you should see 3 to 5 more inches of water-holding capacity in your soil,” says Towery. “So if it’s dry in July and August, this system shines big time,” resulting in significantly higher yields in dry or drought conditions