Don Biehle is the only far manager that the Southeastern Purdue Ag Center has ever had. He began using cover crops on some of the bulk production fields not used for research, especially those on slopes, many years ago. In fact, he was using cover crops on those Clermont and Avonburg soils long before it was 'cool' to do so.
"We started doing it to protect the soil," he says. "We've also found that a cover crop does a very good job of weed suppression. That can be a real plus."
It's only more recently that Biehle, like farmers across Indiana, have begun to recognize there can be good residual effects from using cover crops. They include improving soil quality and soil health. In certain situation in the spring, a growing cover crop, before it is burned down with chemicals, can also help dry out soils. Wet spoils in the spring that delay planting are a common problem on the heavy, gray, clay soils of southeastern Indiana.
However, Barry Fisher, agronomist for the Natural Resources Conservation Service, notes that while cover crops can be a great tool in your tool box for improving soil quality, they do bring along possible disadvantages. It takes improved management skill to work around these possible obstacles.
"The overall difference is you just need to apply more management skill," he says. "It may mean different equipment, and it may also mean adjusting to differences in timing your crop operations."
Two keys to success with cover corps are seeding at the right time, which varies with the crop, and burning down the cover at the proper time in the spring. When the proper time is can vary with the cover crop and with soil and environmental conditions that spring.
Picking which cover crops will work best to accomplish your goals can be tough, Fisher says. Several provide deep rooting. Some are better at suppressing weeds, others are better at grabbing and holding onto nitrogen. There are also huge differences in seed varieties of each cover crop. It's important to do your homework and get a variety suited to your area, he says. Don't be fooled by this mild winter. Winterkill of cover crops that are supposed to grow through spring can be a big issue most years. Varieties that aren't suited for this climate won't survive in more typical winters.