farming produces same yields but uses less energy and no pesticides
Publication date: July 13, 2005
Posting date: August 03, 2005
Organic farming produces same corn and soybean yields as conventional
farms, but consumes less energy and no pesticides, study finds Susan
Cornell University, July 13, 2005
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
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
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
Systems Trial, the longest running comparison of organic vs. conventional
farming in the United States.
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.
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
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
to 28 percent, the equivalent of taking about 3,500 pounds of carbon
dioxide per hectare out of the air.
Among the study's
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
Organic farming reduced
local and regional groundwater pollution by not applying agricultural
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
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.