MINNEAPOLIS — There are a lot of questions when you decide to plant a cover crop. As with a cash crop, you need to determine what species and variety to plant, when to plant, and what seeding rate to use. Recommendations for these practices depend on a farmer’s cropping system and goals and change with grower experience and peer reviewed research.
The Midwest Cover Crop Council’s Cover Crop Decision Tool utilizes research-based information and grower experience to guide farmers planning to seed a cover crop. Over the last year, a group of Minnesota cover crop experts reviewed and updated the tool, which can be accessed at: https://mccc.msu.edu/covercroptool/
To use the selector tool, first enter both the state and county where you farm. This brings in local weather data, which are used to determine the risk of a killing frost during the late-summer to early-fall cover crop planting season (click on each screen capture for a larger image).
Select your goals
Next, you can enter up to three goals for your cover crop. The expert panel, which included agency, farmer, and extension representatives, rated each cover crop for its ability to provide certain services. “Soil Builder” and “Erosion Fighter” will bring up a good starter species like cereal rye, while “Quick Growth” might be a good choice for a new cover crop user who wants to terminate as early as possible before cash crop planting. If you don’t enter any goals, you’ll get some establishment information for all the cover crops, but no recommendations about which one is ideal for your personal goals.
Next, you can select your cash crop, planting and harvest dates. This gives you a visual on when in the season you’d need to use interseeding technology to seed a certain cover crop species. Additionally you can select the field’s drainage and/or flooding potential to help fine-tune recommendations.
Check out your recommendations
Here, I picked “Quick Growth” and “Soil builder” in Stearns County, which generated a list of species listed in order of suitability for the location and my goals. Note the two yellow or gray boxes next to the name of the species show how each ranked for my goals. Hovering over a species name will also remind you of your goals, and displays the ranking of the species for each goal.
The main part of the table represents a calendar, which shows when you have reliable establishment, and when it’s a little risky (e.g. due to low moisture, the heat of the summer, or freezing temperatures). In this example late in the year, cereal rye looks like the best choice for my farm. A few other species might still establish, like triticale or winter camelina, but they’re not rated highly for quick growth or soil building.
Explore other cover crops
Let’s suppose you decide to go with cereal rye this year, but you want to learn more about sorghum-sudangrass to use earlier in the summer after a canning crop next year. When you click on the species, you get a menu of information, including all-important planting specifics and ratings for success under different types of stress.
There’s a lot to explore here! Using this tool is like inviting ten of Minnesota’s most experienced cover crop users to your farm and getting their recommendations on when and how to seed your cover crop.
Thanks to all those who helped review all the details in this tool. We hope you enjoy exploring options, and please get in touch if you have questions or comments.
— Anna Cates, State soil health specialist, Lizabeth Stahl, Extension educator – crops, and Axel Garcia y Garcia, Agronomist – Sustainable crop systems, University of Minnesota Extension
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