Study identifies areas with significant potential to reduce downstream water pollution from nitrogen fertilizers

Regions are ranked by total nitrogen surplus. (Civil Eats map, University of Vermont data, Rural Blog label)

Nitrogen pollution from fertilizer is a significant—and difficult to solve—environmental issue: runoff contaminates drinking water and causes dead zones and toxic algae blooms in lakes and oceans, and nitrogen released into the air as the potent greenhouse gas nitrous oxide.

A new study from the University of Vermont's Nutrient Cycling and Ecological Design Lab, published in the journal Environmental Research Letters, "identified 20 nitrogen 'hotspots' across the U.S. The clusters of counties not only represent areas where a large proportion of surplus nitrogen is being applied; they are also places where researchers say there is significant potential to reverse the trend—to the benefit of farmers, local residents, and the environment," Lisa Held reports for Civil Eats. "The study comes at an opportune time, as the Biden administration turns its focus to agriculture’s role in fighting climate change, and conversations about scaling up and targeting farm conservation programs are increasing."

The study identifies regions and ranks them by total nitrogen surplus. The first three are not surprising; they are in the corn-and-soybean-growing areas of the Midwest most often identified with nitrogen pollution. Less often identified with the problem are No. 4, the lower Ohio and mid-Mississippi river valleys, and No. 5, which includes parts of four northern Rocky Mountain states.