If you think you're going to try cover crops for the first time this fall and have 100% success, you may not be a candidate to grow cover crops. "You have to manage them," says Ron Althoff of BioTill, Effingham, Ill. "They're like anything else in farming. You need to learn how to manage them to get the benefit form them that you're after."
Dan Towery, Ag Conservation Solutions, LLC, Lafayette, agrees. He has advised many growers and organizations on what to do and not do when it comes to cover crops. Here are some basics both agronomists agree upon.
First, seed when the crop should be seeded. One farmer reports seeding cereal rye around November 1 last year and having a tremendous crop. If you tried to get by with that with some other covers, including annual ryegrass, it would probably be a disaster, they note.
Second, know why you want to grow a cover crop. If it's a compacted field, you may want to grow forage radishes, planted in the fall, Towery says. They are good at opening up big channels closer to the surface than some other cover crops. However, they tend to winterkill in most winters, the last one excluded, and can have a pungent odor when they decay.
Third, use a legume if you want to produce nitrogen for the crop. Hairy vetch is one choice and can produce a large amount of nitrogen, especially if allowed to grow until the second or third week of May, depending upon the season, Althoff says. Waiting that long to plant may or may not fit into your plans.
Austrian peas also are a good nitrogen producer, and another legume.At the field day they were tall and producing pods and seed. That was simply because Wenning planted them in the spring for identification purposes at the field day. They won't look like that if you plant them in the fall, Towery says.