While the benefits might be well known, so are the challenges in developing an on-farm system to work in each situation. Here area few tips to use cover crops throughout the year.
1. Time Your Cover Crop Planting Right
You don’t have to wait for harvest before putting cover crops in the ground. “We started planting cover crops this year on June 15 into 60" row corn,” says Mitchell Hora, a farmer in Washington, Iowa. “We will continue planting cover crops until the early part of December.”
In the northern Corn Belt, Jodi DeJong-Hughes, a regional extension educator with the University of Minnesota, says preharvest is an option for those worried about an earlier blast of winter. “Before the corn is harvested, when it starts to die off and you can get more sunlight down into the ground, we’re going out there with a highboy to put down the cover crops.”
Depending on the fall and the situation, it might be also be an option to establish a cover crop in late winter or early spring ahead of planting.
READ MORE Cover crops to boost soil microbial abundance by 27%
2. Aim for Good Seed-to-Soil Contact
Similar to planting cash crops, make sure cover crop seed is well incorporated if planting into standing crops. “We’ve tried it with airplanes, and most of the time you’re feeding the rodents in the field more than you’re getting that seed-to-soil contact we really need,” DeJong-Hughes says.
3. Let Cover Crops Grow Longer
Planting into a green, well-established cover crop can provide benefits at planting. “It’s another way to dry out soils,” Hora says. “It’s not only utilizing evaporation to dry off the top of the soil surface, but we’re also utilizing transpiration, where the plant can pull moisture from the roots deeper in the soil, up through the plant and exude it out into the atmosphere as water vapor.”
Weed Today, Cover Crop Tomorrow
A weed could one day serve as a new beneficial cover crop. Researchers at universities across the Midwest are working to genetically modify pennycress. The plant yields an oilseed that could be processed into biofuel, animal feed and other products.
Pennycress could produce 2,000 lb. of seed per acre or 80 gal. of oil and is suited for the 80 million acres of corn and soybean ground that typically sits dormant in the winter, says Illinois State researcher John Sedbrook. He believes pennycress, like other cover crops, could also help stem topsoil losses and nutrient runoff.
