Study finds hotspots in U.S. agriculture with greatest potential to reduce nitrogen pollution

The prevalence of synthetic nitrogen-fertilizer use and its negative impacts on the environment are critical considerations in conversations about the future of sustainable and regenerative farming. To reduce environmental impacts of soil fertility management, organic certification prohibits the use of synthetic N-fertilizer, while non-organic farming largely depends on its application for high crop yields. A new study in the journal Environmental Research Letters has identified 20 hotspots across the U.S. that present the greatest opportunities to reduce excess synthetic N-fertilizer use and its associated nitrogen pollution, without compromising crop yield. By mapping cropland “N balances” (N inputs ­– N harvested in crops), the study identified counties that had high N balances, where N reduction would not reduce productivity (indicating areas of N excess). The study simultaneously identified other factors associated with excess nitrogen use such as environmental, economic, social and demographic factors to pinpoint the regions that have the most opportunity to improve their nitrogen management. The 20 hotspots identified by the study represent approximately 24% of cropland area in the U.S., but nearly 65% of excess nitrogen used in U.S. farming. The results of this study are important because they indicate that changes made by a few players could have a tremendous, positive impact on the sustainability of non-organic farming. As farmers improve their fertilizer management, and become less reliant on synthetic nitrogen sources, transition to additional conservation practices and organic farming will become easier.


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