OMAHA (DTN) -- After adopting no-till and mastering its challenges, many growers are ready to move to the next level in soil saving by adding a cover crop to their rotation. Cover crops also can supply winter grazing and spring haying, build organic matter, fix nitrogen, scavenge nutrients and suppress weeds.

Getting a cover crop planted after harvesting corn and soybeans is a challenge. Time is short. Farmers are busy with harvest and other fall field activities.

Farmer Paul Ackley from Bedford, Iowa, has experimented with cover crops for the past few years to develop a system for his corn and soybean rotation on the highly erodible landscape in the southwestern part of his state.

"I started working with cover crops to conserve the soil," said Ackley. "I am now interested in more opportunities for including cover crops after corn and soybeans. The more vegetation that is growing over the soil for longer periods of time means the more soil is protected, the more carbon is being sequestered, the more nitrogen is being scavenged and there will be more nutrient cycling."

Dan Gillespie is a no-till specialist with the Natural Resource Conservation Service and farms near Meadow Grove, Neb. He has planted rye after corn and soybeans. He actively promotes cover crops in Nebraska and tests them on his farm. He successfully incorporated rye after soybeans in his rotation, but is still dabbling with rye after corn.

CEREAL RYE IS EASY SOLUTION

"Cereal rye is the only easy solution for (corn and soybean) growers," said cover crop expert Steve Groff, owner of Cedar Meadows farm. "They need to plant short-season corn or soybeans. Early harvest is critical, so they can plant (rye) earlier in the fall and leave the cover longer in the spring."

Gillespie suggested farmers plant winter cereals or ryegrass after harvesting soybeans. They should be aerial seeded from mid-August to mid-September after leaf drop. If growers are interested in fall grazing, oats could be added to produce more fall growth.

Allen Dean, from Bryan, Ohio, plants annual ryegrass, because it's cheaper than cereal rye and its deep root system scavenges more nutrients, but does not produce as much top growth as rye. However, the crop needs to be seeded in late summer or early fall, then killed early before it gets to boot stage.

Gillespie recommended that after corn, farmers aerial seed rye from mid-August to mid-September. However, if a cover crop is aerial seeded in standing corn, expect a good portion of the seed to get hung up in plant material and not germinate.

Gillespie said waiting until after harvest to drill is risky because farmers won't see much fall growth. The later the crop is seeded, the less growth there is.

CHALLENGES TO START COVER CROP

Ackley acknowledged the challenges in trying to grow a cover crop are getting it started. "I have been trying to find a cover crop to go behind soybeans for several years. I had tried rye (after soybeans and) in front of corn for several years and failed. So we went with it behind corn and in front of soybeans instead where it fits better."

Dwayne Beck, agronomist and manager of the Dakota Lakes Research Farm near Pierre, S.D., said growers need to remember that it is just another crop in the rotation. It needs to be managed to get the full benefit.

Beck doesn't believe that growers can effectively use a cover crop in the corn and soybean rotation, which he considers too short and an inadequate rotation. He advocates for longer rotations that include winter cereals such as wheat to add diversity to the rotation.

Beck has planted winter cereals after corn harvest in South Dakota. "It is not ideal this far north, but it works. We do it after corn going to beans the next year."

ISSUES TO THINK ABOUT

If farmers consider planting a cover crop, there are a number of issues to think. Gillespie said the first is seed. "There are only a few species available and commercial seed is costly."

Second is planting. "Rarely is there enough time in the fall to plant a cover crop in a timely fashion and get everything else done," he said.

Third is equipment. "Farmers who no longer have (no-till) drills have to rent one. Aerial seeding is a risky proposition."

Fourth is economics. "There is the high cost of planting and no perceived economic return from the investment," Gillespie said.

Rye and wheat are the most popular cover crops for a number of reasons. They are easy to establish and fast growing, and seed is readily available and relatively inexpensive. Legumes, on the other hand, have to be planted earlier and do not provide cover as rapidly, but they do supply some nitrogen that can be used by the next corn crop.

In the midst of harvest and fall field activities, "farmers have to tool up to plant cover crops if they want to get it done and you need a dedicated man and equipment. If you don't prepare, it won't get planted." said Ed Winkle, a consultant with HyMark Consulting in Martinsville, Ohio.

Daniel Davidson can be reached at [email protected]