While there are several good options for terminating cover crops, it’s important to understand which cover crop termination methods work best for your specific cover cropping system and overall operational goals.
Cover crop termination methods
Six common approaches are used by most farmers when terminating cover crops. Here’s how they work and under which conditions.
Herbicides for terminating cover crops
In most cases, cover crops should be terminated before planting corn, soybeans or other crops. In general, experts recommend terminating cover crops 10-14 days before planting corn.1 That time window is less important for soybeans, though research suggests termination within one week of planting is often ideal.2
Herbicides such as glyphosate and 2,4-D are commonly used when terminating cover crops. Contact herbicides tend to work best on small annual plants. If you plant multiple cover crop species together, you might need to use several different herbicides.
Tillage for terminating cover crops
Balance cover crop termination methods with good soil health practices. You can kill cover crops by mechanically uprooting them or disturbing the soil. Moldboard plows and chisel plowing are most effective for terminating cover crops and managing crop residue, but they can also damage soil structure, so tillage should be used mindfully.3
Mowing for cover crop termination
Although mowing can reduce cover-crop biomass, it’s not an ideal termination method. Cutting must remove all plant growing points, many of which are often below ground during the vegetative stage. Always combine mowing with other methods to ensure full termination.
Roller crimping
Roller crimping involves mechanical flattening and crimping to kill cover crops without the need for herbicide application. Work with a trusted adviser to determine when you should do this to consistently kill plants, particularly if you plant multiple cover crop species. Roller crimping is often used in conservation tillage or no till cover crop termination environments. It’s especially effective with covers such as cereal rye at the post-pollen shed stage.
Harvesting cover crop as silage
Turning cover crops into livestock feed is another viable option. Benefits of this approach include cost savings on forage, consistency of forage supply and even livestock weight gain comparable to pasture grazing.4 For maximum efficacy, time your harvest to maximize the nutritional quality and biomass. Also be aware of tradeoffs: Your soil residue cover might decline, and you’ll have less available residue to decompose and contribute to soil organic matter.
Grazing livestock on cover crops
As with silage harvesting, livestock grazing can bring benefits and tradeoffs. Benefits include the ability to quickly terminate covers and reduce biomass. Tradeoffs include reduced soil residue coverage, lower residue benefits and the need to provide proper fencing.
Importance of cover crop termination timing
You should decide when to go ahead with terminating cover crops based in part on a few key timing considerations.
Time your cover crop termination to maximize biomass benefits
When you delay termination until the right moment, often around mid-May in parts of the Midwest, you’re allowing for increased biomass compared to a late-April termination date. This can double or triple the amount of available biomass for your fields, contributing soil organic matter, nutrient cycling and erosion protection.5
How to time your cover crop termination
It’s important to terminate when the time is right, ideally 10 days to two weeks pre-plant, to mitigate several risk factors.6 First, cover crops can utilize available water, leading to soil moisture depletion. Second, pests can use cover crops as a “green bridge” to transfer into cash crops. Third, grass cover crops in particular can nab available nitrogen from your cash crop. Fourth, excessive residue in your fields can make planting a chore and require specialized equipment.
Balancing factors and adaptive strategies
With so many conditions at play when managing cover crop termination, here are some ways you can strike the right balance:
- Evaluate local soil moisture conditions and weather forecasts to terminate in a way that avoids moisture stress.
- Scout and consider earlier termination to break pest cycles.
- Consider cover crop species and residue C:N ratio to ensure plenty of nitrogen will be ready for your cash crop.
- Use equipment designed for planting into crop residue.
- Adapt termination timing and methods each year based on field conditions, crop rotation and cover crop goals.
Experts are available to help you make your decisions about terminating cover crops. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- Anderson, Meaghan, Rebecca Vittetoe, and Bob Hartzler. “Terminating Cover Crops - What’s Your Plan?” Integrated Crop Management, Iowa State University Extension and Outreach, 22 Mar. 2016, https://crops.extension.iastate.edu/cropnews/2016/03/terminating-cover-crops-whats-your-plan. Accessed 29 Sept. 2025.
- Hayley Nelson. “Terminating Cover Crops After Seeding Soybeans.” Practical Farmers of Iowa, 11 Jan. 2022, practicalfarmers.org/research/terminating-cover-crops-after-seeding-soybeans/. Accessed 17 Oct. 2025.
- Hill, Erin, and Christy Sprague. “Cover Crop Termination.” MSU Extension, Michigan State University, 22 Apr. 2024, https://www.canr.msu.edu/resources/cover-crop-termination. Accessed 29 Sept. 2025.
- “Research Shows Cover Crops’ Value as Cattle Feed.” CALS Iowa State University, 21 Aug. 2019, www.cals.iastate.edu/news/2019/iowa-state-researchers-show-cover-crops-value-cattle-feed. Accessed 16 Oct. 2025.
- Phyllis Bongard. “Strategic Farming: Let’s Talk Crops! Focused on Weed Management.” Minnesota Crop News, University of Minnesota Extension, 8 Feb. 2022, blog-crop-news.extension.umn.edu/2022/02/strategic-farming-lets-talk-crops.html. Accessed 16 Oct. 2025.
- Jenny Brhel, Chris Proctor, Katja Koehler-Cole, and Amit Jhala. “Cover Crop Termination Tradeoffs.” CropWatch, University of Nebraska–Lincoln Extension, 8 Apr. 2021 (updated 9 Apr. 2025), cropwatch.unl.edu/2021/cover-crop-termination-tradeoffs/. Accessed 16 Oct. 2025.
