“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.

http://www.ns.umich.edu/htdocs/releases/story.php?id=5936