- Organic farms are more efficient than their conventional
cousins and leave soils far healthier, researchers report today in the
journal Science. In a long-term study comparing productivity, environmental
health, biodiversity and energy consumption of organic cultivation to conventional
methods, Paul Mäder of the Research Institute of Organic Agriculture
in Switzerland and his colleagues found that the organic approach used
significantly less energy to produce the same quantity of crop. Though
organic farms typically produce lower overall yields than common plots
do, their ecological benefits are greater a larger number of pest-eating
creatures and other advantageous organisms live in soil farmed organically
and decomposition occurs more efficiently on these lands, releasing much
needed nutrients into the soil.
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- In 1978, the researchers began studying four plots of
land planted with winter wheat, potatoes, beets, grass clover and barley
(see image). Farmers cultivated two of these fields conventionally. For
the remainder, they utilized organic methods, substituting compost and
manure for synthetic fertilizers and using mechanical weeding and plant
extracts instead of chemical pesticides. The scientists found that organic
soils harbored about 50 percent fewer nutrients (because plants received
no artificial fertilizer), but yielded on average only 20 percent less
crop. Thus, plants farmed organically used available nutrients more efficiently.
How does this happen? It seems that biodiversity on organic land is far
higher than in traditionally cultivated soils. Moreover, root-colonizing
fungi that help plants absorb nutrients, as well as pest-eating spiders
and nutrient-cycling soil microbes, exist in significantly greater numbers
on organically tilled plots.
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- Detractors of organic farming point out that even though
such methods might work well in Switzerland, they may not be profitable
in countries where the government does not subsidize farmers. In addition,
such so-called natural methods may be difficult to apply on a larger scale,
as in commercial farms in the U.S. But this 21-year study suggests that
organic cultivation may be both more sustainable than traditional pesticide
and fertilizer-driven practices and as prosperous. "I think our research
could stimulate governments to encourage [organic methods] by showing long
term benefits," Mäder remarks. "These results are encouraging
for farmers, because they can see that yields are stable over time, and
that soil fertility has increased." --Rachael Moeller
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- RELATED LINKS
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- http://www.sciam.com/news/041901/3.html
- Analysis Finds Greater Profits from Organic Farming
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- http://www.sciam.com/2001/0201issue/0201postel.html
- Growing More Food with Less Water
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- http://www.sciam.com/news/092000/1.html
- Delivering Fungicides on Bee Feet
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- http://www.sciam.com/news/111600/5.html
- Combating Corn Borers
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- http://www.sciam.com/news/053102/1.html
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