When you visit the 2013 Farm Progress Show in Decatur, Ill., you will find some 18 plots of various cover crop combinations along with soil pits so you can see what the cover crops are doing below ground. But you won't find wheat as a cover crop – and there are some reasons for that.
Mike Plumer, former Extension specialist in Agronomy at the University of Illinois, now a farmer and private consultant, believes that there are far better choices for cover crops than wheat. Plumer designed and has overseen the plots all along.
He says wheat has some inherent problems when used as a cover crop that make it less than desirable as a choice to plant to cover the soil during the winter to prevent soil erosion, and to get growth in the fall and spring, plus rooting action, to promote soil health.
Reasons for not using wheat, Plumer says, include planting it often before the hessian fly-free date. In areas where wheat is grown as a crop, he sees that as a major issue. Second, it is the host for a fusarium fungus and other diseases that could affect crops planted into the cover. It also is more attractive to cutworm and armyworm than rye.
Third, he believes it increases the chances for Sudden Death Syndrome in soybeans if you are planting soybeans into the cover.
Finally, Plumer believes wheat causes major nutrient tie-ups at planting time. There can also be an allelopathic effect on corn as the wheat residue decays.
The bottom line is he believes that there are better, and even more economical, choices for cover crops than wheat.