One farmer attended a recent field day on cover crops because cost-share money is available in his county to establish cover crops. He hasn't tried them before, but he does no-till. He figures that with help to cover the cost of seed, it's time the tries the practice on his own farm.
Doing something just to get government money may not be the best reason, but it you're also interested in achieving other benefits at the same time, it may be an acceptable one. Years ago farmers who tried cover crops were those who were mainly sticklers for soil conservation. They didn't want their fields exposed during the winter with no live cover where the soil would be an easy target for soil erosion, especially after soybeans, since the crop leaves such little residue.
Today, more people are using them, often but not exclusively in no-till systems, to seek help in opening up the soil for deeper rooting, and to capture nitrogen, either left over from the year before, so it doesn't wind up leaching into tile lines and running off into bodies of water, or to grow nitrogen as a legume taking N out of the air.
Dan Towery, an agronomist with his own company, Ag Conservation Solutions, LLC, says it's important to know what benefits you're after before you start down the road with cover crops. What you're trying to accomplish will impact which crops you try, and perhaps which varieties of those cover crops. All annual ryegrass, for example, isn't created equal. Some varieties are much more adopted to typical winters in Indiana than others. This past winter dos not qualify as a typical winter, and cover crops that don't survive normal winters survived this past winter in some cases.
Still, even if you're not doing it primarily for soil erosion concerns and you're on rolling land, you need to keep that objective in mind, Towery says.
"You wouldn't want to plant only covers that winterkill going into winter," he says. "Then the soil would be bare and unprotected fro the rest of winter and spring. That's one reason why we often suggest mixing more than one cover crop together when you seed in the fall. You want to make sure you still have a cover crop living in the winter and spring so that the soil is protected from soil erosion."