Cover Crop Management Options to Improve Weed Control, Crop Yield and Soil Health – Kansas

Longest-running experiment in the Mid-Western U.S. demonstrates the economic and soil-health benefits of cover crops as cattle forage.

Whether you graze cover crops with livestock or you hay it, you get an economic benefit even if it impacts your next crop yield.”

—Dr. Augustine Obour, Research and Education Grantee

Crop-Livestock Integrated Systems are Economically Viable

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The Success Story

In the semiarid central Great Plains, drought conditions increasingly contribute to crop failure and soil erosion. Cover crop integration is a promising ameliorative strategy that generates harvestable forage for the region’s livestock and offsets cash crop revenue loss. As part of the only long-term (8 years in 2024) grazing cover crop experiment in the Western U.S., Dr. Obour and his research team demonstrated that replacing a fallow treatment (with herbicide application) with a crop-livestock integrated system achieves a net economic benefit while improving soil health. With data to support the benefits of this climate-smart practice, policymakers now encourage cover crop grazing and farmers are reaping the benefits.

Grantee (Researcher) Highlights

As a university-based professor, Dr. Obour is reliant on grant funding to propel his research. He has successfully sustained cover crop research at the Kansas State University Agricultural Research Center-Hays since 2015, prolifically publishing and presenting on the findings. From these activities, Dr. Obour has built a reputation as a soil management and agronomic production expert in the North Central region and in Ghana, where he first began studying crop science at the Kwame Nkrumah University of Science & Technology.

Other Stakeholder (Graduate Students, Producers, Agricultueral Service Providers, Consultants) Highlights

Dr. Obour relied heavily on a master’s degree student, Mr. Logan Simon, who collected most of the soil measurements for the project. Simon was subsequently admitted as a PhD student in Agronomy, with Dr. Obour serving as his advisor. A SARE graduate student grant is funding his research to determine the optimum amount of cover crop biomass removal to balance grazing and soil-health goals. Simon, who graduates in 2024, has already been hired as an Assistant Professor at Kansas State University. The farmers who opened their land for Dr. Obour’s on-farm research project continue to employ forage cover cropping. Trusted sources of guidance that farmers rely on, including agriculture consultants and NRCS staff, are now advocating for the practice. This has led to farmers throughout the region experimenting and adapting their plots from season to season, deepening knowledge about the timing and crop types that generate the greatest benefit in varied contexts.

Sustainability Impacts

Prior to this project, it was believed that using cover crops for forage would reduce biomass inputs to a degree that exposed the soil to erosion. By demonstrating that grazing does not cause this negative impact, more farmers are adopting the practice. Environmental sustainability impacts include reduced soil erosion, improved nutrient cycling, suppression of herbicide resistant weeds, and improved soil health. Producers employing the practice also benefit from enhanced crop profitability as they produce forage for the region’s livestock. While the project began as a cover crop experiment, it is evolving to examine crop-livestock integrated systems as a climate-smart tactic in the face of unpredictable weather. Even if the primary grain crop grown on the land fails, the cover crop can be grazed or harvested, contributing income to the enterprise while concurrently improving soil quality.

Barriers

Complex economic issues pose ongoing challenges to adoption of cover crops for cattle forage in the region. While the study demonstrated net economic gains during the grant period, the cost of cover crop seed has since increased, driven by federal subsidies. In cases where a cover crop is planted but not used for forage or hay production, the net revenue is now less than would be generated by leaving the plot fallow and applying chemical herbicides. Crop insurance is also problematic, as adjustors assume cover cropping increases the likelihood of crop failure. This is because, prior to Dr. Obour’s research, it was believed that cover crops’ water use would reduce subsequent cash crop yield and increase instances of crop failure.

Contributors

On-farm research is vital to demonstrate that research findings generated at university experimentation sites are transferrable to large-scale production settings. SARE’s unique emphasis on farmer partnerships made possible Dr. Obour’s validation of preliminary findings that have justified recommending the practice more broadly to farmers.