Pros and cons of biofuel production

Every spring and summer, a “dead zone” of oxygen-poor waters the size of Massachusetts forms in the Gulf of Mexico. Fish, crab and shrimp catches decrease in these hypoxic waters, which lose oxygen due to massive algal blooms triggered by fertilizer runoff.

The zone has existed for at least 50 years, and the Environmental Protection Agency has set goals to shrink this massive zone. Recent federal mandates to grow more biofuels in the agricultural region that drains into the Mississippi River basin promise to hinder those efforts, according to a new report.

Researchers from the Carnegie Mellon University in Pittsburgh concluded that “meeting the biofuel goals set forth [by the federal government] will likely increase the occurrence of hypoxia … regardless of the selection of crops.”

Some biofuel advocates had suggested that growing switchgrass and other biofuel crops that need less fertilizer than corn and soybeans would help reduce the nitrate pollution. The scientists said the change to more cellulose-based crops could cut nitrate runoff by as much as 20 percent, but that is not enough to meet EPA runoff targets intended to reduce the size of the dead zone.

The scientists advocate aggressive nutrient management that includes wetland construction, vegetative buffers, tillage management and precision fertilizer application.

“Only when all the nitrogen runoff associated with the production of corn, soy, and switchgrass is reduced will the EPA goal be met,” the study said. The report will appear in the October issue of the journal Environmental Science and Technology.

Jim Dawson reports for Inside Science News Service, which is supported by the American Institute of Physics, a not-for-profit publisher of scientific journals.

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Comments (3)

  1. Submitted by Burton'Jon Blackwell on 09/21/2009 - 10:35 am.

    Here’s what I know about ethanol!…..
    It takes one energy unit to produce .78% of an energy unit from petroleum. It takes one energy unit to produce 1.78 energy units from corn. It takes one energy unit to produce 7 energy units from sugarcane, and sugarcane is the most efficient plant that be used to reclaim energy in the form of ethanol. There is a midwestern agricultural commodity that ranks second in production efficiency only to sugarcane. One unit of energy will produce 4.7 energy units from our popular sugarbeets. Our beet’s are grown predominately in river bottom land. Why not beets?
    P.S. It takes one energy unit to produce 2.9 energy units from russet patatos.


    • Submitted by Joe Smithers on 10/28/2014 - 02:03 pm.

      energy units

      Where did you get your data from? What study and year? I would like to know if you based this information on current information or on information from the 70’s like so many people like to do when bashing ethanol.

  2. Submitted by Joe Smithers on 11/05/2014 - 03:56 pm.

    energy units

    Here are the real numbers from the MDA. According to the U.S. Department of Energy, 0.74 units of fossil energy are needed to produce 1 unit of energy from corn ethanol. In comparison, one unit of gasoline requires approximately 1.23 units of fossil energy inputs. Cellulosic ethanol is projected to have an even more positive energy balance, requiring about 0.1 units of fossil energy per 1 unit of renewable energy.

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