With the rising number of herbicide-resistant weeds, it’s become more important to use a varied approach to weed control in order to manage resistance more effectively.
Planting the same crop in the same field year after year allows weeds to adapt and become harder to control. Learn how growing a variety of crops in rotation can reduce weed populations.
Benefits of crop rotation to decrease weed diversity
While research indicates that tillage and herbicides are the primary drivers of reducing weed density, crop rotation is a key practice to decrease the diversity of weed species since each crop has unique natural abilities to suppress weeds.¹
Planting timing also impacts weed suppression. For example, planting soybeans early gives soybeans a head start in canopy growth, increasing their competitiveness against early-season weed growth. Starting off strong with weed control is critical as research shows that early-season soybean weed control (before the V3 growth stage) has the greatest impact on corn and soybean yields.²
More crops in the rotation = better weed control
Weeds thrive in monoculture environments, so alternating between broadleaf (soybean) and grass (corn) crops opens up weed control options. Even better, incorporating new crops to the rotation, like wheat and alfalfa, can help diversify weed-management tactics.
Additionally, research conducted in the Northern corn belt found that including winter cover crops like wheat once every four years in rotation with corn and soybean produced many benefits, including increased corn and soybean yields. Further benefits include improved soil structure and, subsequently, reduced soil erosion and runoff risk.³
Rotating between warm- and cool-season crops also suppresses weeds
Rotating between two warm-season crops, such as corn or soybeans, and two cool-season crops, such as wheat or alfalfa, can provide a weed control advantage by disrupting weed life cycles.
Research showed the lowest weed density occurred when two years of cool-season crops were followed by two years of warm-season crops because weeds are forced to survive three years before they are able to grow and multiply.⁴
Increased modes of action
Generally, you should avoid making two consecutive applications of herbicides with the same mode of action in one field without adding other methods of control. Crop rotation allows for flexibility in applying various herbicide formulations specific to different cropss.
Herbicide formulations that contain multiple modes of action and have long-lasting residual control on resistant weeds like Palmer amaranth and waterhemp can be effective at keeping resistant weed populations in check.
Experts are available to help you make your decisions. 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
- Mwangi, Obadiah, et al. “Organic Farming Practices Increase Weed Density and Diversity over Conventional Practices: A Meta-analysis.” PMC Home, National Library of Medicine | National Center for Biotechnology Information, 8 June 2024, pmc.ncbi.nlm.nih.gov/articles/PMC11215295/. Accessed 16 Aug. 2026.
- Proctor, Chris. “Mid-season Weed Management in Corn and Soybean.” CropWatch, 21 Feb. 2020, cropwatch.unl.edu/2019/mid-season-weed-management-corn-and-soybean. Accessed 16 August, 2026.
- Chakravorty, Adityarup. “Benefits of Wheat in Corn-Soybean Rotations.” Soil Science Society of America, 17 May 2021, www.soils.org/news/science-news/benefits-wheat-corn-soybean-crop-rotations/. Accessed 16 August, 2026.
- Sexton, Peter. “A Look at Crop Rotation and Soybean Production.” SDSU Extension. Mar. 2020, extension.sdstate.edu/sites/default/files/2020-03/S-0004-04-Soybean.pdf. Accessed 20 Sept. 2024
