Agronomic and economic aspects of integrating a winter annual cereal into a corn-soybean rotation in Michigan cropping systems

The addition of a winter annual cereal into a Michigan corn-soybean rotation had direct impacts on many agronomic and economic aspects of the cropping system. Winter wheat (Triticum aestivum L.) and rye ( Secale cereale L.) scavenged nitrogen over the fall and winter compared with having no cover crop present. With a late April glyphosate burn down of wheat or rye cover crops, the killed plants began to release nitrogen to the soil by the first week of June. Winter annual cereals were able to provide a second profitable crop to the system when harvested as forage. Insect pressure on rotational crops following winter annual cereals varied by the crop and insect, but often were dependant on rotational crop planting date. Soybean [Glycine max (L.) Merr.] yield following a wheat or rye cover crop may be increased over no cover crop, while corn grain (Zea mays L.) and corn silage yield tended to follow a pattern of higher yield with earlier corn planting date, which ultimately depended on whether the winter annual cereal was used for a cover crop, forage, or grain. Depending on the planting date of the corn or soybean rotational crop following harvest of a winter annual cereal, the economic benefit of the additional crop may increase or decrease the net profit to the system.