[Mb-civic] Organic Farming Produces Same Corn and Soybean Yields as Conventional Farms, but Consumes Less Energy and No Pesticides, Study Finds

[Michael Butler]

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    Organic Farming Produces Same Corn and Soybean Yields as Conventional
Farms,
    but Consumes Less Energy and No Pesticides, Study Finds
    By Susan S. Lang
    Cornell University

    Wednesday 13 July 2005

    Ithaca, NY - Organic farming produces the same yields of corn and
soybeans as does conventional farming, but uses 30 percent less energy, less
water and no pesticides, a review of a 22-year farming trial study
concludes.

    David Pimentel, a Cornell University professor of ecology and
agriculture, concludes, "Organic farming offers real advantages for such
crops as corn and soybeans." Pimentel is the lead author of a study that is
published in the July issue of Bioscience (Vol. 55:7) analyzing the
environmental, energy and economic costs and benefits of growing soybeans
and corn organically versus conventionally. The study is a review of the
Rodale Institute Farming Systems Trial, the longest running comparison of
organic vs. conventional farming in the United States.

    "Organic farming approaches for these crops not only use an average of
30 percent less fossil energy but also conserve more water in the soil,
induce less erosion, maintain soil quality and conserve more biological
resources than conventional farming does," Pimentel added.

    The study compared a conventional farm that used recommended fertilizer
and pesticide applications with an organic animal-based farm (where manure
was applied) and an organic legume-based farm (that used a three-year
rotation of hairy vetch/corn and rye/soybeans and wheat). The two organic
systems received no chemical fertilizers or pesticides.

    Inter-institutional collaboration included Rodale Institute agronomists
Paul Hepperly and Rita Seidel, U.S. Department of Agriculture's Agricultural
Research Service research microbiologist David Douds Jr. and University of
Maryland agricultural economist James Hanson. The research compared soil
fungi activity, crop yields, energy efficiency, costs, organic matter
changes over time, nitrogen accumulation and nitrate leaching across organic
and conventional agricultural systems.

    "First and foremost, we found that corn and soybean yields were the same
across the three systems," said Pimentel, who noted that although organic
corn yields were about one-third lower during the first four years of the
study, over time the organic systems produced higher yields, especially
under drought conditions. The reason was that wind and water erosion
degraded the soil on the conventional farm while the soil on the organic
farms steadily improved in organic matter, moisture, microbial activity and
other soil quality indicators.

    The fact that organic agriculture systems also absorb and retain
significant amounts of carbon in the soil has implications for global
warming, Pimentel said, pointing out that soil carbon in the organic systems
increased by 15 to 28 percent, the equivalent of taking about 3,500 pounds
of carbon dioxide per hectare out of the air.

    Among the study's other findings:

    * In the drought years, 1988 to 1998, corn yields in the legume-based
system were 22 percent higher than yields in the conventional system.
    * The soil nitrogen levels in the organic farming systems increased 8 to
15 percent. Nitrate leaching was about equivalent in the organic and
conventional farming systems.
    * Organic farming reduced local and regional groundwater pollution by
not applying agricultural chemicals.

    Pimentel noted that although cash crops cannot be grown as frequently
over time on organic farms because of the dependence on cultural practices
to supply nutrients and control pests and because labor costs average about
15 percent higher in organic farming systems, the higher prices that organic
foods command in the marketplace still make the net economic return per acre
either equal to or higher than that of conventionally produced crops.

    Organic farming can compete effectively in growing corn, soybeans,
wheat, barley and other grains, Pimentel said, but it might not be as
favorable for growing such crops as grapes, apples, cherries and potatoes,
which have greater pest problems.

    The study was funded by the Rodale Institute and included a review of
current literature on organic and conventional agriculture comparisons.
According to Pimentel, dozens of scientific papers reporting on research
from the Rodale Institute Farming Systems Trial have been published in
prestigious refereed journals over the past 20 years.