1.Organic farming can feed the world, U-M study shows
2.Organic agriculture and the global food supply - Abstract
NOTE: The finding that yields in developing countries could increase dramatically by switching to organic farming confirms previous findings - see, for instance: http://www.lobbywatch.org/archive2.asp?arcid=7370
1.Organic farming can feed the world, U-M study shows
University of Michigan, July 10 2007
Listen to podcast
Podcast En Espanol
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.
Researchers from the University of Michigan found that in developed countries, yields were almost equal on organic and conventional farms. In developing countries, food production could double or triple using organic methods, said Ivette Perfecto, professor at U-M's School of Natural Resources and Environment, and one the study's principal investigators. 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 from U-M.
"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 Southern Michigan.
"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:
School of Natural Resources and Environment http://www.snre.umich.edu/
See the article
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1091304 [or below]
Contact: Laura Bailey
Phone: (734) 647-1848
2.Organic agriculture and the global food supply
Research Article - Abstract
Renewable Agriculture and Food Systems (2007), 22: 86-108 Cambridge University Press doi:10.1017/S1742170507001640 Published online by Cambridge University Press 04Jul2007
Catherine Badgleya1, Jeremy Moghtadera2a3, Eileen Quinteroa2, Emily Zakema4, M. Jahi Chappella5, Katia Avilés-VÃ¡zqueza2, Andrea Samulona2 and Ivette Perfectoa2 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
a1 Museum of Palaeontology, University of Michigan, Ann Arbor, MI 48109, USA.
a2 School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109 USA.
a3 Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA.
a4 School of Art and Design, University of Michigan, Ann Arbor, MI 48109, USA.
a5 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.