Fertilizer use poses environmental risks, even climate change, but state-based regulation hasn't proven effective

Orange area is annual "dead zone" in the Gulf of Mexico,
caused mainly by fertilizer in Mississippi River watershed.
(Image from four-minute video by Grist)

Fertilizer has caused more environmental problems in recent years, and regulation by states has been ineffective, Joe Wertz reports for The Center for Public Integrity's nonprofit newsroom.

"In America’s Corn Belt and around the world, some of the fertilizer applied to fields escapes the soil in new forms that contaminate and warm the planet. Some of these compounds enter the atmosphere as a potent greenhouse gas that’s now at its highest concentration in the last 800,000 years, helping fuel climate problems like the flooding that upended farmers’ lives last spring," Wertz reports. "Other fertilizer byproducts contaminate water wells, especially in agricultural areas, where the U.S. Geological Survey says one in five has levels exceeding federal health limits. These contaminants also wash into streams, rivers and lakes, where they become what the U.S. Environmental Protection Agency calls 'one of America’s most widespread, costly and challenging environmental problems.'"

Farmers are using 40 times more nitrogen than they did 75 years ago, and though EPA has advised limiting its use for years, states have most of the authority and have preferred to depend on voluntary cooperation instead of laws that enforce compliance. "An investigation by the Center for Public Integrity, Grist and The World found that when states do try to regulate farms and reduce pollution linked to fertilizer, rules are often derailed or softened after industry pushback and political pressure," Wertz reports.

The video with the report emphasizes one solution: cover crops that keep rain and snow from hitting bare soil and leaching its nutrients into streams. It says only 4 percent of U.S. cropland is planted in cover crops after harvests. It cites a cover-crop experiment in the small watershed of the William Baker Ditch in northern Indiana, which reduced runoff by half, nitrates 20% and phosphorus 70%.