Report links fuel to dead zone

As the nation’s demand for ethanol drives record corn production in the Midwest and increased fertilizer runoff into the Mississippi River, shrinking the annual "dead zone" that forms off Louisiana’s coast will be "practically impossible" without major changes, according to a report this week in the Proceedings of the National Academy of Sciences.

 

The study is one of several released in the past year that analyzes the relationship between biofuel production and nutrients that eventually flow into the Gulf of Mexico. The researchers from the University of British Columbia and the University of Wisconsin created a series of models to show how ethanol production goals set by Congress would dramatically boost the amount of nitrogen flowing into the Mississippi River system.

 

"Expanding corn-based ethanol production would make the already difficult challenges of reducing nitrogen export to the Gulf of Mexico . . . practically impossible without large shifts in food production and agricultural management," the report states.

 

Fertilizers from corn and other crops in Midwestern states wash into streams and rivers from the farmlands, funneling large amounts of nitrogen and phosphorus into the Gulf of Mexico. The same nutrients that feed corn and wheat production combine with sunlight to fuel explosive algae blooms in the Gulf that cloud waters and suck up the oxygen available for marine life. The resulting "dead zone" causes fish to either flee or perish.

 

Last year’s dead zone measured 7,915 square miles — close to the size of New Jersey, and one of the largest ever recorded.

 

Professors Simon Donner and Christopher Kucharik found that nitrogen runoff into the Gulf could increase by 10 percent to 18 percent if farmers meet the congressional goal of producing 15 billion gallons of corn-based ethanol by 2022. To reach that conclusion, they used statistics from the U.S. Agriculture Department and computer models that monitor how nitrogen leaks into river systems.

 

Although corn is not the only crop that can be used to produce ethanol, it is by far the most widely used in the United States so far. Corn requires more artificial fertilizer than other crops such as soybeans, thus producing more nitrogen runoff.

Last year the U.S. produced 6.5 billion gallons of ethanol, according to the Renewable Fuels Association, a 30 percent increase from 2006. And farmland devoted to corn surpassed 90 million acres last year, a 20 percent increase from 2006.

 

The report comes just weeks after a federal-state dead zone task force approved a plan meant to reduce the dead zone to a fraction of its size by 2015. Without targeted federal financing and tighter restrictions on nutrient pollution, many scientists say the plan is unlikely to succeed.

 

To reduce nitrogen runoff to a point that would meet the 2015 dead zone reduction goal, the report says farmers would have to make drastic changes to meet the corn production goals: installing wetland buffer zones beside every corn and soybean field in the Mississippi basin, and reducing the amount of corn used to feed livestock. Americans would thus have to change their diets to eat much less meat, requiring "a substantial change in culture."

 

"The take-home message from that is, ‘Wow, this is going to be difficult to do,’ " said Donner, a professor of geography at the University of British Columbia. "As we look at biofuels and producing food for the world, we may need to look at these land-use tradeoffs that come into play."