Cover crops 2025: What should you plant?

By: Anna Cates, Extension soil health specialist; Liz Stahl, Extension Educator - Crops; and Axel Garcia y Garcia, Sustainable Cropping Systems Specialist 

We’re nearing the end of a pretty solid growing season for corn and soybeans, and it will soon be time for harvest and other fall activities – like planting cover crops! Given the huge soil losses we saw with wind erosion across Minnesota last winter, this is a great year to start thinking about how to protect your soil from wind and water losses. Cover crops can also help manage water by building soil structure, which you need to both store and infiltrate water…because you never know when the next drought, wind storm, or 8 inches of rain will come along.

Over the 2024-25 winter, we tested a few different combinations of cover crop species and seeding rates, and learned a few things worth sharing.

Oats

In one trial, we looked at oats at seeding rates from 10 to 60 lbs/ac, mixed with radish at 1 to 6 lb/ac. At our St. Paul research site, we found that these treatments all produced more than 850 lbs/ac of biomass, and, in Waseca, from 2,200 to 3,000 lb/ac of biomass. In Lamberton, biomass produced by the oat/radish mix ranged from 425 to 540 lb/ac, which still provided a respectable amount of ground cover over the winter. We did prioritize planting these before mid-September, and used a drill to get good establishment in a dry fall, but these results reinforce our perception of oats as a go-to quick-growing grass to build your mix around if you want something that winter-kills. (And as recently noted, it’s not a host for many small grain pests.)

Cereal rye

We also looked at cereal rye at a variety of seeding rates. At the U of MN Research and Outreach Centers in Crookston, Lamberton, and Waseca, we drilled rye at either 15 lbs or 60 lbs in fall 2024, and found no difference in total biomass produced in spring 2025 (mostly around 500 to 1000 lb, depending on seeding date and location). In another study, we found that rye seeded between 10 and 80 lbs/ac at St. Paul, Lamberton, and Waseca all yielded over 2000 lb/ac in biomass by termination at planting May 5-15. In a third study at Lamberton, Waseca, and Grand Rapids, we found that even rye seeding rates up to 135 lb/ac didn’t produce more biomass or ground cover than just 27 lb/ac. Later termination did increase biomass though. Although seeding cereal rye at 10-30 lbs/ac is too low to get cost-share from most programs, the rye seed is a very affordable replacement for fall tillage costs at these lower rates.

Other mixes

We haven’t looked a lot at different species, focusing on ones frequently used successfully by farmers, but, at Crookston, a mix of field pea, oats, buckwheat, winter rye, and hairy vetch left 500 to 1000 lb/ac biomass in the spring, consisting mostly of rye and a little vetch. Winter barley, or a mix of field pea, oats, and buckwheat, on the other hand, produced less than 100 lb/ac biomass before winter-killing.

Drone seeding

Credit: Dru Larson (Dakota County SWCD)

We experimented a little with using a drone to seed rye at 15 and 30 lbs/ac at Lamberton in the fall of 2024, but didn’t have a lot of success with this (both produced less than 200 lb/ac of biomass in the spring). Conditions were very dry before and after seeding, and a lack of moisture, combined with a lack of seed-to-soil contact, hurt establishment. Broadcasting 60 lb/ac rye and incorporating was relatively successful at Waseca and Lamberton, but not as effective as drilling. We certainly cross our fingers for some more timely rains this fall, but keep in mind aerial seeding is always a riskier practice. It might be worth it to take a field pass off your plate, but establishment is usually poorer than drilling, and higher seeding rates are justified.

Spring-planting cover crops

At a couple of sites, we also looked at spring-planting cover crops. This was very successful in one Lamberton plot where a rye/oat/flax mix planted April 10 produced more than1500 lb/ac biomass by the time it was terminated June 5. On the other hand, in Crookston, we tried seeding rye and vetch Feb 20, and produced <200 lb/ac biomass.

Cover crop economics

Of course, a key test will be to see if these cover crops and differences in biomass affect cash crop yield at the end of the season. Despite a dry fall, we saw a lot of spring growth in these plots, and sometimes that can compete with cash crop seedlings. It’s very difficult to put a dollar amount on the value of protecting your fields from topsoil losses, but cover crops should protect the long-term productivity of the soil – while hopefully breaking even in the short-term. We’ll share that data as we have it, but hopefully the sneak previews above give you some ideas about how to apply cover crops in a low-risk way that works for your operation.

Funding for these trials was provided by the Minnesota NRCS, General Mills, and the Environmental and Natural Resources Trust Fund.

Additional resources:

• On-farm research: Can a rye cover crop reduce wind erosion after sugarbeet?
• Strategic Farming webinar recap: Cover crops and nutrient interactions
• The state of Minnesota's soil health: How many farmers are doing no-till, cover crops, and more
• Video: How do cover crops, nitrogen rate and cropping system affect nitrate loss?

---

For the latest nutrient management information, subscribe to the Nutrient Management Podcast. And don't forget to subscribe to the Minnesota Crop News daily or weekly email newsletter, subscribe to our YouTube channel, like UMN Extension Nutrient Management on Facebook, follow us on X (formerly twitter), and visit our website.

If you have questions or comments, please email us at nutmgmt@umn.edu.