A complete ban or restriction on the broad-spectrum herbicide glyphosate could cost Illinois corn and soybean farmers between US $300 million and $609 million per year, representing a direct revenue loss of 1.8% to 3.6% across the state.

Published in the online edition of the journal Weed Technology, the independent study provides a transparent, evidence-based assessment of how the removal of glyphosate would affect agricultural revenues through yield penalties and increased input costs.

The research was conducted by Sandy Dall'erba and Aaron Hager, professors at the University of Illinois Urbana-Champaign, alongside Corey Lacey of the Illinois Soybean Association. The findings offer operational guidance for crop producers, agronomists, and agricultural policymakers preparing for potential regulatory shifts.

Economic and Yield Impacts on Row-Crop Systems

Classified by the Weed Science Society of America (WSSA) as a Group 9 herbicide, glyphosate has been a cornerstone of commercial weed management since its introduction in 1974. Over five decades, the active ingredient has enabled widespread adoption of conservation tillage and reduced-till farming, delivering significant soil conservation benefits and operational cost efficiencies across North America.

Despite these established agronomic benefits, the authors acknowledge that escalating regulatory scrutiny, ongoing litigation, rising herbicide resistance, and public debate have heightened the possibility of future restrictions or an outright ban on the chemical.

According to the study's models, an unmitigated loss of glyphosate without operational adaptation would trigger substantial yield losses, particularly within corn production. However, researchers emphasise that total unmitigated yield loss is unlikely in practice, as commercial growers would rapidly alter weed control protocols.

Operational Complexity and Herbicide Substitution

While substitute chemical formulations exist, the research underscores that replacing glyphosate comes with measurable financial and management hurdles for agricultural operations.

Key findings regarding herbicide substitution include:

🌾 Higher Input Costs: Transitioning to alternative chemical active ingredients requires higher expenditure on crop protection inputs and application equipment.

⏱️ Tighter Application Windows: Alternative herbicides generally require narrower weather and crop-stage timing windows to achieve effective control, increasing operational risk.

🚜 Increased Operational Complexity: Most viable alternative programmes require multiple passes across fields, increasing fuel consumption, labour requirements, and machinery wear.

🌤️ Environmental Sensitivity: Alternative chemistry options demand heightened monitoring of weather conditions, soil moisture, and ambient temperatures to prevent crop injury and maintain efficacy.

The authors note that even under successful chemical substitution strategies, modest yield penalties remain likely during the transition period as farm managers refine new weed control protocols.

Integrated Weed Management

To mitigate financial losses and protect long-term soil health, the study stresses the necessity of early adaptation and integrated weed management (IWM) strategies.

The researchers advise that farm businesses that proactively diversify weed management approaches, combining targeted chemical rotation with non-chemical control methods such as cover crops, mechanical cultivation, and seed bank management, will be best positioned to absorb potential regulatory changes.

By testing alternative chemical formulations and adjusting operational practices prior to potential statutory restrictions, row-crop producers can minimise input cost spikes and safeguard crop yields across future trading cycles.