Organic Farming Can Feed the World, Research Finds
A new study published in the journal Renewable Agriculture and Food Systems has found that organic agriculture has the potential to contribute substantially to the global food supply (Item 1). This finding is particularly important for developing countries, where farmers can access the materials needed for organic agriculture more easily.
The researchers examined a global dataset of 293 examples, and found that on average, in developed countries, organic systems produce 92% of the yield produced by conventional agriculture. In developing countries, however, organic systems produce 80% more than conventional farms. The authors also found that organic methods could produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without putting more farmland into production.
Moreover, contrary to fears that there are insufficient quantities of organically acceptable fertilizers, the data suggest that leguminous cover crops could fix enough nitrogen to replace the amount of synthetic fertilizer currently in use.
With best wishes,
Organic agriculture and the global food supply
Research Article - Abstract
and Food Systems (2007), 22: 86-108
Published online by Cambridge University Press 04Jul2007
Catherine Badgleya , Jeremy Moghtader [a2, a3], Eileen Quintero [a2], Emily Zakem [a4], M. Jahi Chappell [a5], Katia Avilés-Vázquez [a2], Andrea Samulon [a2] and Ivette Perfecto [a2,c1]
The principal objections to the proposition that organic agriculture can contribute significantly to the global food supply are low yields and insufficient quantities of organically acceptable fertilizers. We evaluated the universality of both claims. For the first claim, we compared yields of organic versus conventional or low-intensive food production for a global dataset of 293 examples and estimated the average yield ratio (organic:non-organic) of different food categories for the developed and the developing world. For most food categories, the average yield ratio was slightly <1.0 for studies in the developed world and >1.0 for studies in the developing world. With the average yield ratios, we modeled the global food supply that could be grown organically on the current agricultural land base. Model estimates indicate that organic methods could produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without increasing the agricultural land base. We also evaluated the amount of nitrogen potentially available from fixation by leguminous cover crops used as fertilizer. Data from temperate and tropical agroecosystems suggest that leguminous cover crops could fix enough nitrogen to replace the amount of synthetic fertilizer currently in use. These results indicate that organic agriculture has the potential to contribute quite substantially to the global food supply, while reducing the detrimental environmental impacts of conventional agriculture. Evaluation and review of this paper have raised important issues about crop rotations under organic versus conventional agriculture and the reliability of grey-literature sources. An ongoing dialogue on these subjects can be found in the Forum editorial of this issue.
(Accepted June 09 2006)
Key Words: organic agriculture; conventional agriculture; organic yields; global food supply; cover crop
c1 Corresponding author: firstname.lastname@example.org
a3 Department of
a5 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Organic farming can feed the world, U-M study shows
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ANN ARBOR, Mich. - 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 findings which refute the long-standing claim that organic farming methods cannot produce enough food to feed the global population.
"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.
In addition to equal or greater yields, the authors found that those yields could be accomplished using existing quantities of organic fertilizers, without putting more farmland into production.
The idea to undertake
an exhaustive review of existing data about yields and nitrogen availability
was fueled in a roundabout way, when Perfecto and Badgley were teaching
a class about the global food system and visiting farms in
"We were struck by how much food the organic farmers would produce," Perfecto said. The researchers set about compiling data from published literature to investigate the two chief objections to organic farming: low yields and lack of organically acceptable nitrogen sources.
Their findings refute those key arguments, Perfecto said, and confirm that organic farming is less environmentally harmful yet can potentially produce more than enough food. This is especially good news for developing countries, where it's sometimes impossible to deliver food from outside, so farmers must supply their own. Yields in developing countries could increase dramatically by switching to organic farming, Perfecto said.
While that seems counterintuitive, it makes sense because in developing countries, many farmers still do not have the access to the expensive fertilizers and pesticides that farmers use in developed countries to produce those high yields, she said.
After comparing yields of organic and non-organic farms, the researchers looked at nitrogen availability. To do so, they multiplied the current farm land area by the average amount of nitrogen available for production crops if so-called "green manures" were planted between growing seasons. Green manures are cover crops which are plowed into the soil to provide natural soil amendments. They found that planting green manures between growing seasons provided enough nitrogen to replace synthetic fertilizers.
Organic farming is important because conventional agriculture - which involves high-yielding plants, mechanized tillage, synthetic fertilizers and biocides - is so detrimental to the environment, Perfecto said. For instance, 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 emission, increased pest resistance and loss of biodiversity.
For their analysis, researchers defined the term organic as: practices referred to as sustainable or ecological; that utilize non-synthetic nutrient cycling processes; that exclude or rarely use synthetic pesticides; and sustain or regenerate the soil quality.
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.
More about Perfecto, visit:
See the article
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1091304 Contact: Laura Bailey
Organic farming could feed the world
12 July 2007
A switch to organic farming would not reduce the world's food supply and could also increase food security in developing countries, say the authors of a new study.
They claim their findings lay to rest the debate over whether organic farming could sustainably feed the world. Organic farming avoids or heavily restricts the use of synthetic pesticides and fertilisers, as well as livestock feed additives.
Numerous studies have compared the yields of organic and conventional methods for individual crops and animal products (see 20-year study backs organic farming).
Now, a team of researchers has compiled research from 293 different comparisons into a single study to assess the overall efficiency of the two agricultural systems.
Perfecto points out that the materials needed for organic farming are more accessible to farmers in poor countries.
Those poor farmers may buy the same seeds as conventional farms use in rich countries, but they cannot afford the fertilisers and pesticides needed for intensive agriculture. However, "organic fertiliser doesn't cost much - they can produce it on their own farms", says Perfecto.
Using data from the UN Food and Agriculture Organization, the team then estimated what would happen if farms worldwide were to switch to organic methods today.
The world currently produces the equivalent of 2786 calories per person per day. The researchers found that under an organic-only regime, farms could produce between 2641 and 4381 calories per person per day.
Perfecto's colleague Catherine Badgley says she believes the calculations they carried out to arrive at the upper number are more realistic. These took into account the higher yields that would be obtained in developing countries, and the details of which crops are grown where.
She points out that even the lower number is sufficient to feed the world. Nutritionists recommend that people consume between 2100 and 2500 calories a day.
The debate over whether the world can produce enough organic food is misplaced, argues Perfecto: "We are producing enough food - it's a question of distribution of that food."
The researchers also found that small farms tend to produce more per hectare of land. "An increase in the number of small farms would enhance food production," they say. They also note that although organic production tends to require more labour, this labour is often spread out more evenly over the growing season, making it easier to manage.
Carl Pray, at
But, he says, "the
likelihood of all farms reverting to 'small farmerdom' is a big question
in an age in which labour is becoming more and more expensive. Take
Perfecto, however, maintains that the idea that conventional farming is cheap is a fallacy. "That is not including the real costs. Once you incorporate the cost to the health of people, once you incorporate the environment cost - then organic agriculture is a much superior system."
Pesticides are associated with a number of diseases, including cancer - a fact that was first brought to public attention in Rachel Carson's book Silent Spring. Organic farming is thought to benefit biodiversity and the environment, as well as human health.
Journal reference: Renewable Agriculture and Food Systems (vol 22, p 86)