Terminating Spring Cover Crops

If you planted cover crops last fall, they protected the soil surface and improved soil health. But if they didn’t die off naturally over the winter, you’ll have to kill them soon so you can plant your cash crop. Traditionally, cover crops are terminated one-to-two-weeks before planting by rolling, tillage, or chemical control. The keys for success are finding what works for you, being timely, and on-target with the process.

Kevin Bradley is an extension weed scientist at the University of Missouri. He says there is a growing trend of “planting green” where producers plant into the cover crop and then terminate it soon after.

"They’re just leaving it there and they’re going to plant into it. Usually within a week, sometimes the exact same day as they plant, then we can go through with a herbicide application to finish that cover crop off," says Bradley. "It really does depend on what cover crop we’re talking about, but more often than not I see people doing this with cereal rye."

The cover crop is starting to die off on its own, but the herbicide provides a faster kill. Keep in mind the type of herbicide, the rate used, and the environmental conditions are factors in success.

"Be cautious of significant swings in temperature because that can affect the efficacy of most of these things that we’d be using to burn it down. And then of course I’d say the other factor is just the cover crop itself," he says.  'We find that some are pretty easy to kill, and cereal rye would certainly fall into the category of being pretty easy to deal with. However, rye grass is probably the other extreme, not so easy to deal with."