The idea of double cropping soybeans and wheat has been the subject of three research projects in recent years.
The first is a 10-year project run by Bruce MacKellar, MSU Extension, in southwest Michigan that looks at successive double-cropping – planting wheat after soybeans are off the land. The Michigan Wheat Program helped fund the 2013 year of this project.
The second project by The Ohio State University looks at interseeding, which allows both crops to be in the ground simultaneously. This may help make up some time to ensure the soybean crop is more likely to reach maturity by the end of the season.
More recently, Dr. Kim Cassida, MSU Extension forage crops specialist, completed a four-year study of the impact on double cropping with common cover crops on soil health.
Note: 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 input costs under high-management against the apparent improved performance.
Research by Dr. Kim Cassida
This report by Dr. Kim Cassida, MSU Extension forage crops specialist, and her research team covers two cycles of corn-wheat rotations with a double crop planting of cover crops at an East Lansing location. The project looked at nine potential cover crops planted after wheat harvest and before corn was planted the following spring, to determine the level of soil benefits provided by each crop, and whether partial removal of the cover crop was detrimental.
The study found that in these two observation cycles, cover crops did not affect soil carbon or nitrogen levels, had varying nutritive qualities, in one case reduced corn yield, and posed some challenges in chemical termination. Summer-seeded cover crops double-cropped after wheat can be harvested as forage with no negative impact on future corn yields, although the economic benefit may be questionable.
Click below to read the final report from this four-year project, and a more complete look at the advantages and disadvantages of the cover crops used in this study.
Research by Laura Lindsey, The Ohio State University
Concluding a two-year project in 2015, Dr. Laura Lindsey and Eric Richer of The Ohio State University looked into another aspect of double cropping wheat and soybeans. Their work focused on interseeding soybeans into wheat to mitigate concerns about an early winter damaging a soybean crop.
In 2013, the project began to look at planting wheat in 15-inch row widths rather than the traditional 7.5 inches. In the 15-inch row, Lindsey and Richer looked at the optimal seeding rate of wheat for interseeding, settling upon 1 million seeds per acre in this three-site trial.
Click below to read the 2015 final report to the Michigan Wheat Program by Dr. Laura Lindsey and Eric Richer, as well as a crop bulletin summarizing the research, which took place just across the Michigan border in northern Ohio.
This research continues. MSU wheat specialist Dennis Pennington has a Michigan research plot, which complements the Ohio work.
Research by Bruce MacKellar
Bruce MacKellar, MSU Extension educator in VanBuren County, has run a double cropping program with wheat and soybeans on land in St. Joseph County, located in southwest Michigan. The project goal is to determine whether soybeans may be planted after wheat is harvested, and successfully matured before a killing winter frost.
In short, results of the research show that second crop soybeans could have been successfully raised in 70-80 percent of the growing seasons since 2004, based on the weather in south central St. Joseph County. While soybean yields are impacted, the second crop on the same land in the same year may balance the financial picture.
Click below to read MacKellar’s final report from the 2013 year of this project, which was supported by the Michigan Wheat Program.