WASHINGTON (February 10, 2026)—Minnesota farmers who grow corn and soybeans in rotation use far more nitrogen fertilizer than crops can absorb with the surplus wasting them money, polluting drinking water, and producing climate emissions comparable to hundreds of thousands of gasoline-powered cars each year, according to a new report by the Union of Concerned Scientists (UCS).
The report estimates that Minnesota corn–soybean producers overapplied from 170,000 to 280,000 metric tons of synthetic nitrogen fertilizer in 2023, producing avoidable heat-trapping emissions equivalent to between 400,000 and 700,000 gas-powered cars driven for a year.
Nitrogen fertilizer is currently used in quantities far greater than what crops need or can absorb, with research showing that as much as half applied by farmers to their corn-soy rotation is unnecessary. The excess runs off to waterways, leaches into groundwater, or turns into climate-heating gases such as nitrous oxide and carbon dioxide that are released into the atmosphere.
“Giant fertilizer corporations have used aggressive marketing to convince farmers that spraying more of their product will bring them greater crop yields,” said Dr. Omanjana Goswami, co-author of the report and an interdisciplinary scientist with the UCS Food and Environment Program. “As fertilizer prices continue to rise, this overdependence is lowering profit margins for farmers while boosting the revenue of the multi-billion-dollar fertilizer industry.”
U.S. farmers spend about $36 billion a year on fertilizer, and for many corn producers that cost represents one of the single largest line items in their budgets—often more than a third of their production costs.
Nitrous oxide, one of the gases emitted from commercial fertilizers, is 273 times more potent as a climate pollutant than carbon dioxide. Agriculture is the largest human-caused source of the long-lasting gas in the United States—with synthetic nitrogen fertilizer accounting for most of those emissions.
The UCS analysis found that excessive use of nitrogen fertilizer by Minnesota corn-soy farmers emits between 1.7 million and 2.9 million metric tons of heat-trapping emissions a year, and as much as 60 million metric tons of gases are released nationally.
“The rising rates of nitrogen fertilizer use have costly consequences for the health of people, our economy, and our environment,” said Dr. Precious Tshabalala, co-author of the report and a scientist with the UCS Food and Environment Program. “Applying twice as much synthetic fertilizer than necessary spews polluting emissions that further heat the climate and endanger public health in rural communities.”
The analysis recommends increased funding for U.S. Department of Agriculture conservation programs that help farmers adopt practices that reduce fertilizer overuse, which Congress can do now in the upcoming farm bill negotiations. The UCS research suggests that greater investment in these programs can benefit farmers, strengthen rural economies, and reduce climate-damaging emissions.
Dr. Tshabalala said implementing conservation practices such as nutrient management can significantly reduce climate emissions while also lowering operating costs, saving farmers an average of $30 per acre in fertilizer costs.
“Rampant overuse of synthetic nitrogen fertilizer is creating a multi-pronged pollution crisis by damaging aquatic ecosystems, contaminating drinking water, and accelerating the climate crisis,” Dr. Goswami said. “If more farmers can gain access to federal conservation resources and reduce their reliance on synthetic fertilizers, it will help to build a more sustainable, healthy and resilient agriculture system.”
Additional Resources:
Full report: “Less Fertilizer, Better Outcomes: USDA Conservation Programs Benefit Both Farmers and the Planet”
Blog post: “From Fields to Faucets: Fertilizer Overuse Threatens Drinking Water and Health”
Blog post: “Half Wasted: Fertilizer Overuse, Pollution, and the Global Nitrogen Cycle”
Blog post: “Farmers Will Pay More for Fertilizer Because of President Trump’s Tariffs”
Explainer: “What’s the Problem with Fossil Fuel-Based Fertilizer?”