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Cover Crops Create Savings
When Jack Thornton planted a 15-acre cereal rye cover crop in 2011, his goal was to stop erosion and runoff on sandy hills in his Reed City, Michigan, fields. Five years later, he planted 300 acres of cover crops on sandy and clay soils and committed to “keep a living root in the soil 365 days a year.”
“Cover crops are something I’m always going to be planting because of the benefits of (improved) soil structure and soil health – and also for livestock feed,” Thornton says.
His farm operation has reduced costs and harvested higher yields due to management practices he has incorporated since he started farming in 2008. For example, one field was ready for corn harvest when he started farming. It yielded less than 80 bushels per acre. In 2015, the same field averaged about 150 bushels per acre of corn. Implementing no-till, paying attention to soil pH, and using the right fertilizers are part of that, but Thornton emphasizes that cover crops are essential to the overall management plan.
Thornton saw the positive difference the first cover crop made, and he wanted more. He connected with Natural Resources Conservation Service (NRCS) and Extension services, and the following year he planted cover crop mixes between rows of corn and soybeans in mid-July with a drill he modified. The fourth year, he stepped up his program and modified a high-boy sprayer by adding an air seeder to plant cover crops and to side-dress fertilizer or spray at the same time.
“It broadcasts through drop tubes to get through the canopy of the row crop,” Thornton says, noting that he starts to plant cover crops around July 1.
He broadcasts red clover seed in his oat and wheat fields earlier when spraying herbicides in the spring.
Moisture is always a concern on nonirrigated ground, but Thornton says the cover crop seems to hold moisture in the root zone and benefit row crops. To ensure that a cover crop survives through extremely dry weather, he always includes drought-hardy varieties in his eight- to 12-way cover crop blends.
The blends also vary slightly between sandy and clay soils.
“For clay, I add more pounds per acre of radish and turnip; they are the deep penetrators,” he says. “I try to keep the cost around $30 per acre.”
Other than the cost of seed, cover crops don’t add management expenses, because the seed is planted the same time Thornton fertilizes or sprays. He says there are three reasons the cover crops save more money than they cost.
- Thornton’s long-term goal to build organic matter is an alternative to more expensive options such as adding irrigation or tiling. Incorporating management practices that focus on the soil will hopefully eliminate the need for the costly options. “By adding 1% organic matter, it adds 27,000 gallons – or 1 acre-inch of water-holding capacity to help through dry spells,” he says.
- Thornton has eliminated pesticides with crop rotations because he’s growing multispecies plants (including row and cover crops). Better soil microbiology creates a more natural cycling of nutrients and pest control.
- Instead of killing the 2017 cover crop next spring, Thornton plans to add another level of management to his operation: livestock. After the crops come off this fall, 40 cow/calf pairs will graze the fields using the paddock system.
“I won’t let them graze down to the dirt, but with radish and turnip roots 30 inches deep or so, there are still roots in the ground even if they eat the tops. The manure brings in biology.”
After grazing the cover crop, Thornton plans to set up bales in the fields for bale grazing, which will put even more nutrients from manure directly on the fields. “If I can produce an easy 2,000 pounds of dry matter per acre for cattle to eat for $30 per acre (the cost of cover crop seed), why wouldn’t I do that?” Thornton asks.
Thornton credits all of his management practices (including cover crops) for positive changes in just a few years.
“The soil is getting darker, and the soil is warming up faster now than the neighbor’s field,” he notes. Extension staff checked the temperatures in fields that had a blanket of clover from the cover crop mix, and they were 1˚ to 2˚ warmer than other fields.
With no-till, Thornton doesn’t need to spend a week preparing fields, and he usually gets into his fields sooner. “I can feel the difference in the clay, heavy soils,” he says. “I can tell at harvesttime – in part, from the mat – that I’m not getting the ruts and the ponding of water. The equipment floats better.”
An unexpected benefit of exploring cover crops and other management practices is a new sideline business. Thornton Agriculture offers cover crop consultation services, seed sales, and management. In 2017, Thornton is contracted to plant cover crops on 3,000 acres, in addition to his own 300 acres.
Thornton has come a long way since planting that first cereal rye cover crop, but he highly recommends it for producers interested in growing cover crops.
“For a single-species plant, cereal rye is very flexible, easy to manage, and good for the soil,” Thornton says. “It overwinters and dies with tillage or herbicides. It can be planted any time of the year as long as there is sun and moisture in the soil, but usually fall works the best.”
By working with Extension and NRCS, he has tried different mixes and planting times. Including species that survive dry weather (such as Sudan grass, millet, and cowpeas) is crucial, he says.
“The other challenge is overall management,” Thornton adds.
In the past, he had success killing the cover crop by spraying just before, during, or right after planting the row crop. In 2016, crimson clover and turnips made him modify that idea.
“I was nervous when they didn’t die right away. They died in time, but I thought they would be brown in 10 days. It took an extra week,” he says.
The lesson is, Thornton says, some cover crops need to be sprayed sooner rather than later. “It’s all part of the learning curve,” he says.
Though he lists many benefits of cover crops, for Thornton, organic matter is the top focus. Improving soil health means it will release nitrogen and other nutrients to plants, which reduces input costs. It takes time to make those gains, but Thornton’s soils are now close to 3% organic matter, up from low to mid 2%.
“I’m working toward 6% organic matter,” he says. “In years past, it was said that’s not possible. But I’m learning from other farmers that I can attain that and have 120 to 150 pounds of nitrogen available to a crop.
“That’s the main purpose,” he notes. “The other purpose is to stop soil erosion so that I hold the nutrients I have in the soil right now.”