Crop rotation is a time-tested practice based on the very sound theory that using the same soil for the same crop year after year can deplete nutrients and lead to a build-up of pests or disease.
Corn-soybeans and corn-soybeans-wheat are common crop rotations in Michigan, as there are lots of anecdotal thoughts and reasons for doing so. Yet there is little scientific data on the benefit of wheat in the rotation or the benefits of rotation vs. single-crop systems.
To expand knowledge on wheat’s value in a crop rotation, in 2016 the Michigan Wheat Program pledged $700,000 to help MSU purchase additional land at the MSU Extension Saginaw Valley Research & Education Center near Frankenmuth. The agreement required MSU to regularly include wheat in crop rotation studies, as well as committing MSU to continue wheat research for the next 25 years.
The Michigan Wheat Program has also directly funded crop rotation research to provide more information on best practices for Michigan wheat farmers, with those reports below.
MSU and the Michigan Wheat Program caution that three years of data should be reviewed to get a more complete picture of research results. Farmers also must weigh their own management style to make the best decision for their farms.
Research by Dennis Pennington
This on-farm trial by MSU wheat specialist Dennis Pennington looked at whether double-cropping (soybeans following wheat), which is popular in Kentucky and Ohio, would be effective in Michigan. The advantage could be increased farm profit by producing a second crop in the same year on the same ground.
Four wheat varieties were planted on the Henry Miller Farm in St. Joseph County, Michigan. After harvest, a single variety of soybean was planted on each of the four wheat plots to determine the benefit of harvesting wheat a bit early and potentially having drying costs for it – yet getting in a second crop of soybeans.
Overall, the one-year demonstration project saw a positive economic result for this farmer. Pennington notes the economic cost of drying early harvested wheat in order to plant soybeans, must be weighed against the soybean yield. More research would be needed to prove the somewhat weather-dependent concept in Michigan.
Click below to review the 2018 final report.
Research by Dean Baas, Dale Mutch
In years past, crop rotations were more diverse. That raises the question of whether more sophisticated crop rotations would increase wheat yields, improve soil quality and decrease pests.
This project set out to evaluate agronomic performance and changes in soil health under four different cropping regimens: 1) continuous corn, 2) continuous soybeans, 3) corn/soybean rotations and 4) corn/soybean/wheat rotations with and without cover crops. The trials were conducted at two locations.
The research suggests that diversification of the cropping system increased corn yield at one site and increased soybean yield at another. That said, building soil health is a slow process and additional years of rotation would be needed for a more definitive answer.
Click below to read the 2017 final report on the project from Baas.