By: Dr. Erin Burns, Michigan State University
Integrated weed management options for sustainable crop production can include strategies such as planting cover crops. One major barrier to cover crop adoption in Michigan and the upper Midwest is achieving the large amount of biomass necessary for weed suppression. Although interseeding into corn is an option for some to establish cover crops earlier, the cost of equipment and unpredictability of summer precipitation can make this difficult.
An alternative approach to maximizing cover crop biomass is to utilize corn breeding improvements such as those found in early maturing hybrids. This research investigates early maturing hybrids, differences in planting date, herbicide programs, cover crop species and their combined effects on weed control and crop yield.
To date, two field studies are in progress at Michigan State University. Three maturity rates are being tested – 89, 99, and 109 (Figure 1), and two cover crop species combinations will be planted this fall: winter hardy grass only, and winter hardy grass + legume mix. Spring termination of the cover crops will either be one week prior to, or at soybean planting. Stand counts, leaf number, time to tasseling and silking, and weed density data have been collected throughout the growing season.
When asked about the value of this research to farmers, Dr. Erin Burns said, “cover crop establishment is difficult with a short planting window after corn, so optimizing factors like maturity date makes it a little easier to manipulate the environment to our benefit – ultimately controlling weeds.”
Next steps: This is the second year for this research project. Upon completion, data from both years will be analyzed for trends and the results will be published in the CMPM annual research report, which will be released in early 2023.
(Figure 1: corn plot on Michigan State University campus with differences in three maturity rates visible)