Rewarding fertilizer pollution with crop subsidies
A new study follows the money to nitrate hot spots in the U.S. Midwest.
U.S. taxpayers are, in effect, subsidizing the Gulf of Mexico’s dead zone, an area of coastal waters where dissolved-oxygen concentrations fall to less than 2 parts per million every summer, according to a paper published today on ES&T’s website (DOI: 10.1021/es070179e). These findings don’t bode well for the Gulf, as more and more acres of land are planted with corn to meet the growing U.S. demand for alternative fuels.
Scientists studying nutrient inputs that feed the Gulf’s hypoxic zone have known that certain intensively farmed areas in the upper Midwest leak more nitrogen derived from fertilizers than others. Now, there’s a new twist. Farmers in areas with the highest rates of fertilizer runoff tend to receive the biggest payouts in federal crop subsidies, says Mary Booth, lead author of the paper and a former senior scientist with the Environmental Working Group. What’s more, they have fewer acres enrolled in conservation programs compared with other parts of the Mississippi River basin (MRB).
Modeling the major sources of nitrate in the MRB, Booth and her colleagues found that fertilizer runoff is responsible for 59% of springtime nitrate loading to the Gulf, atmospheric deposition for 17%, animal waste for 13%, and municipal wastewater for 11%. In addition, almost half of the fertilizer losses come from an intensively farmed region—primarily Illinois, Iowa, and southern Minnesota—that constitutes just 5% of the entire MRB.
These findings are consistent with earlier analyses but go a step further by homing in on the seasonal aspects of nitrogen flux rather than annual loading, says Richard Alexander, a research hydrologist with the U.S. Geological Survey. “Spring flux is what matters most in predicting the formation of the [Gulf’s] hypoxia zone,” he adds.
Booth’s team added data from federal commodity support and conservation programs to their model. The output shows that a large proportion of the commodity subsidy payments from 1995 to 2002 went to the areas with the most runoff and the least amount of land enrolled in conservation programs.
This paper “points out that a modest shift in federal agricultural spending priorities could help bring about large-scale increases in the type of conservation efforts necessary to restore ecological stability in the Gulf,” says Donald Boesch, president of the University of Maryland’s Center for Environmental Science. That finding correlates with what the U.S. EPA’s Science Advisory Board is recommending in a draft reassessment [PDF size: 3.6 MB] of the state of the science about the Gulf’s hypoxia.
Booth maintains that agricultural nitrate loading could be reduced substantially if farmers took just 3% of the most intensively farmed land out of production. Accomplishing this target, she adds, wouldn’t require a large increase in overall federal funding, but monies would have to be shifted from commodity to conservation programs under the Farm Bill set to expire in September.
Legislation to reauthorize the Farm Bill proposed in January by the Bush Administration moves in that direction. Commodity spending would fall by nearly $4.5 billion, and conservation spending would rise by $7.8 billion over the next 10 years. “That’s a substantial increase over the 2002 Farm Bill for conservation funding,” says Jim Brownlee, a spokesperson for the U.S. Department of Agriculture (USDA). He admits, however, that the growing demand for ethanol is driving up the number of acres planted with corn and could cause land currently in conservation programs to be pulled back into production.
Ethanol production capacity is being ramped up quickly to meet renewable-fuel targets set with the federal Energy Policy Act of 2005 [PDF size: 3.1 MB]. Currently, 114 ethanol refineries produce more than 5.6 billion gallons annually, according to the Renewable Fuels Association. Another 80 refineries are under construction, and 7 are expanding to add more than 6 billion gallons of capacity. To fuel this expansion, USDA predicts, a record 90.5 million acres of corn will be planted this year, 15% more than last year.
“As long as we talk about more corn to serve as feedstock for ethanol, we’ve got some significant problems with nitrogen—no question about it,” says Gyles Randall, a soil scientist at the University of Minnesota.
