Organic farming produces same corn and soybean yields as conventional
farms, but consumes less energy and no pesticides, study finds
By Susan S. Lang
July 13, 2005

http://www.news.cornell.edu/stories/...other.ssl.html

ITHACA, N.Y. -- 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.