As cover crops continue to grow in use, the best advice for those looking to adopt the practice is to try and fail and learn from it.
“Anyone who has ever used cover crops has a story of one thing they’ve done wrong,” said Mark Licht, cropping systems specialist with Iowa State University.
“I’ve talked to a lot of producers and they say you just have to be willing to look in the field and scout and have an open mind. You have to be willing to adjust because what works well one year could totally throw you off the next.”
Cereal rye continues to be the top-planted cover crop in the Midwest, and that doesn’t figure to change much, Licht said. One shift in trend is planting green. The longer covers grow in the spring, the more early-season weed control they can provide, as well as finding a use in livestock grazing which can have multiple benefits.
For those working with small grains, such as wheat, there may be different cover crop options along with other benefits, said Morgan Jennings, field crops viability coordinator with Practical Farmers of Iowa.
“Incorporating a small grain into a typical corn and soybean rotation allows producers to break insect pest and disease cycles that often create problems in corn and soybean rotation systems,” she said. “The disruption of these cycles, even for just a single year out of three, can bring yield benefits to subsequent cash crops.”
The earlier planting opportunity following wheat opens the possibilities for cover crops such as buckwheat, sunflowers, sunn hemp, hairy vetch and radishes, which bring various benefits to soil. Some are able to scavenge nitrogen while others are good for alleviating compaction.
“Once you figure out what you are trying to achieve, you can select cover crops that can help meet those goals,” Jennings said. “Some can produce nitrogen, others are good for forage.”
If forage is the goal, something like pearl millet or sorghum-sudangrass may work well.
“Pearl millet is a good grazing option that can be used for dry hay,” she said. “There is no acid risk so you don’t have to worry about the cattle grazing that.”
There are disadvantages to these more unusual mixes, such as a higher seed cost for the longer-term cover crops as well as increased residue, more management and various sizes of seed which can be difficult to plant.
Termination in the spring can also be a challenge, Licht said. Using the right glyphosate rate is important.
“Herbicidal termination is going to be the most effective method available to most farmers, and despite substantial research into alternatives, glyphosate remains the most consistent product to kill grass species,” Licht said.
