Monsanto expert talks cover crops

ST. LOUIS — Cover crops — plants grown in the off season after corn, soybean or wheat is harvested — have numerous benefits to the soil and ecosystem.

Mike Lohuis serves as director of crop biometrics at Monsanto. He is part of the company’s environmental sustainability team.

From reduced soil compaction to increased organic matter, there are a host of reasons to consider planting them.

Mike Lohuis, director of crop biometrics at Monsanto, discussed cover crop opportunities with AgriNews.

What excites you the most about cover crops?

The thing I’m so excited about is the greenhouse gas part of it. Cover crops can do a nice job of not just soaking up water, but soaking up carbon.

If you can pull more carbon from the atmosphere, carbon dioxide will feed the cover crop and produce more organic matter. Some of that ends up in the soil long term, which becomes a sponge for carbon. It’s a way to pull more carbon dioxide from the atmosphere and store it in the soil.

What other benefits do cover crops have?

It’s one way to help control weeds. It also helps control erosion. Anything we can do to provide more protection for soil, particularly between late fall and early spring, is good.

Cover crops, at the end of the growing season, help sequester remaining nitrogen that may still be in the soil. This is particularly important in dry years when the corn crop does not take up all of the fertilizer, especially nitrogen, applied.

Why is it important to keep nitrogen in the soil?

If you have remaining nitrogen throughout the winter period, you can see some of that leeching out of the soil and ending up in the waterways. Farmers are looking at how cover crops can help reduce nitrogen losses. There are two reasons why you’d want to do that.

One is that you, as a farmer, paid for that nitrogen and you want to keep it for the next year. Secondly, from an environmental perspective, if we don’t control the nitrogen we may end up with environmental liability.

What cover crop advice do you have?

There’s a learning curve. I wouldn’t advise farmers to do their whole farm at once. You want to start slow, with a few acres that you can keep a good eye on.

What plants should farmers consider planting?

The most common grass planted is a cereal rye — it’ easier to establish and easier to terminate than some other grasses. Another grass is rye grass, an excellent cover crop that’s harder to terminate. It’s not one I’d advise farmers to start with.

Other farmers might choose to include some clovers in there, particularly if you want to boost nitrogen content the next year and save on fertilizer costs.

How do you plant cover crops?

A lot of farmers have experimented with flying on cover crop seeds before corn is harvested. In the southern part of the Corn Belt, there is more time to drill it in, which will create a better stand because there’s more seed and soil contact.

Where does Indiana stand?

Indiana was one of the leading states in terms of adoption of cover crops. Indiana’s Natural Resources Conservation Service has done a great job of educating about cover crop and no-till applications.