July 2007
Organic farming can yield up to
three times as much food on individual farms in developing countries as
low-intensive methods on the same land, according to new research that
refutes the long-standing claim that organic farming methods cannot
produce enough food to feed the global population.
Researchers from the University of Michigan said Friday that in developed
countries, yields were almost equal on organic and conventional farms.
But in developing countries, food production could double or triple using
organic methods, said Dr. Ivette Perfecto, professor at the university's
School of Natural Resources and Environment, and one the study's principal
investigators.
"My hope is that we can finally put a nail in the coffin of the idea that
you can't produce enough food through organic agriculture," Perfecto said.
Catherine Badgley, research scientist in the Museum of Paleontology, is a
co-author of the paper along with several current and former graduate and
undergraduate students.
The idea to undertake an exhaustive review of existing data about yields
and nitrogen availability began as Perfecto and Badgley visited farms in
Southern Michigan as part of a class about the global food system.
"We were struck by how much food the organic farmers would produce,"
Perfecto said.
The researchers compiled data from published literature on the chief
objections to organic farming - low yields and lack of organically
acceptable nitrogen sources.
The authors found that the higher yields could be accomplished using
existing quantities of organic fertilizers, without putting more farmland
into production, by using green manures - cover crops plowed into the soil
to provide natural soil amendments.
Perfecto said the idea that people would go hungry if farming went organic
is "ridiculous."
"Corporate interest in agriculture and the way agriculture research has
been conducted in land grant institutions, with a lot of influence by the
chemical companies and pesticide companies as well as fertilizer
companies. All have been playing an important role in convincing the
public that you need to have these inputs to produce food," she said.
Some critics of organic agriculture, including American agricultural
scientist and Nobel Peace Laureate Norman Borlaug, argue that adopting
organic farming methods on a global scale would be more detrimental to the
environment than conventional farming.
Borlaug asserts that if organic farming is to feed the globe, it will
require a large increase in cropland area, and says that achieving this
goal will ultimately lead to wide-scale deforestation.
In the early 1960s, Borlaug developed high yielding, disease resistant
wheat plants and sent trained farmers to spread the technology to more
than 20 nations. He has supported the use of pesticides and genetic
modification of food crops.
The University of Michigan study provides additional evidence for a
growing acceptance of the ability of organic farming to feed the world
without reliance on chemicals and genetic modifications.
"Organic agriculture is no longer a phenomenon in developed countries
only, as it is commercially practiced in 120 countries, representing 31
million hectares and a market of US$40 billion in 2006," the UN Food and
Agriculture Organization, FAO, said at an international conference on
Organic Agriculture and Food Security in Rome in May.
The FAO paper cites recent models of a global food supply grown
organically which indicate that organic agriculture could produce enough
food on a global per capita basis for the current world population.
In a separate study government scientists with the U.S. Department of
Agriculture's Agricultural Research Service, ARS, found that organic
farming can build up soil organic matter better than conventional no-till
farming.
Announcing the results on Tuesday, ARS plant physiologist John Teasdale
said he was surprised to find that organic farming was a better soil
builder than no-till.
No-till has always been thought to be the best soil builder because it
eliminates plowing and minimizes even light tillage to avoid damaging
organic matter and exposing the soil to erosion.
Organic farming, despite its emphasis on building organic matter, was
thought to actually endanger soil because it relies on tillage and
cultivation instead of herbicides to kill weeds.
But Teasdale's nine-year study at the ARS research center in Beltsville,
Maryland showed that organic farming's addition of organic matter in
manure and cover crops more than offset losses from tillage.
"It is one of a few long-term studies comparing organic farming with
no-till," says Teasdale, who heads the Sustainable Agricultural Systems
Lab at Beltsville. "Most others compare organic with conventional
plow-tillage cropping systems."
From 1994 to 2002, Teasdale compared light-tillage organic corn, soybean
and wheat with the same crops grown with no-till plus pesticides and
synthetic fertilizers.
In a followup three year study, Teasdale grew corn with no-till practices
on all plots to see which ones had the most-productive soils. He found
that the organic plots had more carbon and nitrogen and yielded 18 percent
more corn than the other plots did.
Teasdale learned that adding more kinds of crops to the organic rotation
helped control weeds in another long-term experiment begun in 1996.
In an ongoing experiment called the Farming Systems Project, Teasdale and
ARS soil scientist Michel Cavigelli showed that after 10 years, corn
yields were higher in diverse organic rotations that included a perennial
legume.
"This is one of a few studies that consider the effects of rotation length
and crop complexity on organic grain yields," Teasdale says.
The FAO paper agrees, saying, "By managing biodiversity in time
(rotations) and space (mixed cropping), organic farmers use their labour
and environmental services to intensify production in a sustainable way."
"Organic agriculture also breaks the vicious circle of indebtedness for
agricultural inputs which causes an alarming rate of farmers' suicides,"
the FAO paper says.
For instance, more than 2,400 farmers have committed suicide over the past
two years in India's Vidarbha region in the northeastern region of
Maharashtra state. The region's complex problems center on falling cotton
prices, and the farmers' need to purchase high-priced seeds and chemicals.
Organic farming is important, Perfecto said, because conventional
agriculture, which involves high-yielding plants, mechanized tillage,
synthetic fertilizers and biocides, is so detrimental to the environment.
Fertilizer runoff from conventional agriculture is the chief culprit in
creating dead zones - low oxygen areas where marine life cannot survive.
Proponents of organic farming argue that conventional farming also causes
soil erosion, greenhouse gas emissions, increased pest resistance and loss
of biodiversity.
Critics argue that organic food could be less safe than other foods,
because it might increase the risk of exposure to biological contaminants
and food-borne diseases. Critics point out that manure used to fertilize
organic crops might contain human pathogens, mycotoxins from molds, and
antibiotics fed to livestock.
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