Farmers promote benefits of cover crops
J.D. Hollingsworth, soil conservation technician with the U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) in southeast Iowa, said a farmer once described to him what it’s like moving to no-tillage and cover crop conservation practices.
“Conventional till is more like high school football,” Hollingsworth said. “Once you move to no-till, that’s kind of like college football. Then once you add that cover crop, he said it just takes it one more step that you can do to help protect your soil.”
The benefits of utilizing cover crops for soil health, water quality and weed suppression were on full display at an eastern Iowa field day last month where local farmers and ag specialists gathered on a rainy afternoon at the Dennis Campbell family farm in Grand Mound.
Hosted by Iowa Learning Farms, Iowa State University Extension and Outreach and USDA-NRCS, approximately 50 individuals were on hand to discuss planting cereal rye, oats or radishes as cover crops and the rewards cover crops bring to the land.
Cover crops continue to gain in popularity in Iowa due to their many benefits, including reduced soil erosion, weed suppression potential, reduced nitrogen and phosphorous loads entering water bodies and increased organic matter in soil. When paired with no-tillage, additional benefits include increased water filtration and reduced erosion during heavy rain events.
Rye, oats, no-till rye
For Campbell and partners Ken Waechter and Will Fischer, who together operate Crystal Creek Enterprises, soil health and preservation are why they started with cover crops roughly six years ago, but they’re seeing other benefits as well such as weed suppression and water filtration.
“For us, we’re watching our erosion, watching our soil,” said Waechter.
Campbell said they plant oats in the fall, which seems to work best for their operation to maintain soil health, mitigate the effects of rainfall on the soil and for weed suppression in the spring.
“Our primary reason is to hold that soil in place for the next year’s crop,” Campbell said. “And we see soil benefits, too. We love the oats for our system; it works well.
“From our perspective, we love the fall planting of oats, and just (getting) that crop up enough to desiccate on its own over the winter.”
As for the spring rains? The oats are “catching those rain drops. One of the most destructive forces of nature is a raindrop falling on soil. If we can just slow that drop down and then let it displace, that works well for us.”
Hollingsworth said gave a visual demonstration, a slake test, showing how different soils are impacted by water.
Soils that have been tilled fare worse than those in a no-till, cover crop system — breaking up and falling apart more readily, he said.
“Think about when that rain falls on your field; what it’s doing to your soil,” Hollingsworth said. “Dislodging, it’s breaking it apart. We don’t have those biological glues holding those soil particles together to keep the soil in place.”
Mike Paustian farms in Scott County near Walcott and has utilized cover crops for eight years.
“All of our acres are cover cropped,” he said. “We go in right after harvest, right behind the combine running a 30-foot drill. The vast majority of what we’re doing is cereal rye.”
They’ve dabbled in radishes and mixed in some oats. The radishes have worked well planted in the fall, especially for compacted areas. “The next spring you could see it, it’s like somebody took a giant aerator out there,” he said. “You could just see all the holes where those had been.”
For Paustian, rye has been ideal for planting in the fall, and then watching its growth in the spring. They allow the rye to grow taller in the spring before killing it off, as it helps with weed control.
“We’re at a point where we’re pretty much planting all of it green when (the rye is) still growing, and then we’ll come back and terminate it,” he said. Cover crops could also cut down on the amount of herbicide application, he said — something they are exploring.
“We’re going to try maybe cutting back on the first spray pass and come in with the residual with the second (pass) to try and mitigate some of those real late coming weeds,” he explained.
Paustian’s general recommendation is to begin initially with cover crops before soybeans, and then consider the same process before corn.
It’s evident there are multiple ways to initiate cover crop conservation, as farmers employ different strategies and different species, he said.
The end goal is the same — to preserve soil and water quality while handling weed suppression.
“There’s more than one way to do this,” he said. “(We’re) both achieving a lot of the same goals, but we’re going at it in a slightly different manner.”
Paustian said it’s an easy argument to make that there’s a long-term value in cover crops, putting organic matter into the soil and facilitating soil aggregation.
“We want to try and figure out how close we can get to making that cover crop pay for itself in a year,” he said. “If we can do that, then those long-term benefits — that’s just gravy.”
Jason Steele, NRCS area resource scientist, said farmers interested in learning more can contact his office for a soil health assessment. They’ll be able to determine the benefits of a cover crop system and which practices would be best suited for an individual farm.
Coupled with no-till, “cover crops are the key,” he said. Tilling destroys aggregate, and soil needs aggregate material for stability and to hold the soil together, he said.
Want more news on this topic? Farm Bureau members may subscribe for a free email news service, featuring the farm and rural topics that interest them most!