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  • Writer's pictureAnneliese Abbott

"Nature's Acres": Misrepresentation of Research on Organic Yields

Broadbalk wheat yields
Manure-fertilized wheat (FYM) at Rothamsted has always had identical yields to chemically fertilized wheat (NPK)

Beginning in 1950, soil scientists and agronomists began to claim that organic farming couldn’t feed the world. Surprisingly, they did not base those statements on good scientific research. Their articles for the popular press were largely lacking in citations, and the studies they did cite didn’t support their arguments at all.


The first study that scientists cited to support the use of chemical fertilizers was the long-term experiments at the Rothamsted Research Station in England. Started in the 1840s, these ongoing experiments are the oldest in the world. In one of the these experiments, researchers fertilized one wheat field with chemical fertilizers and an identical wheat field with animal manure. Over the years, yields on these two fields were approximately equal.


Yes, that’s right. Chemical fertilizers and animal manure resulted in equally high yields. The chemical fertilizers did not boost yields any higher than the time-honored practice of heavy manure application. So the logical conclusion from the Rothamsted data is that good organic farming will have approximately the same yields as chemically fertilized farming. But agronomists completely ignored the actual conclusions of the Rothamsted studies. They instead continued to stubbornly insist that organic farmers could never attain as high of yields as farmers who used chemical fertilizers—even though they had no data to support that claim.


By the 1970s, organic farming was getting so popular that agronomists couldn’t disdainfully ignore it anymore. So they condescendingly designed a series of experiments to “prove” that organic yields were lower. Most of these experiments compared chemically fertilized plots to plots that received no fertilizer at all. Not surprisingly, the fertilized plots had higher yields. By calling those unfertilized plots “organic,” agronomists “proved” that organic farming couldn’t feed the world. Organic Gardening and Farming printed an article in the July 1972 issue warning about these “Nature’s Acres” plots and worked hard to educate the public that “the absence of chemical fertilizers, herbicides and pesticides does not make a garden organic.” But they didn’t succeed in convincing the agronomists.


Even after scientists did studies actually comparing organic and conventional farms, the way they presented the data reflected their bias against organic farming. When the anti-organic Council for Agricultural Science and Technology (CAST) reviewed studies comparing yields on organic and conventional farms in the late 1970s, most of the yields were fairly similar and some organic farms even out-produced their conventional counterparts. But CAST summarized the findings by saying, “Yield reductions attributed to organic farming ranged between -7 and 44 percent.” In other words, some organic farms had yields 7 percent higher than conventional farms—but CAST still claimed that organic farming always resulted in “yield reductions.”


Except for small-scale studies, which are inconsistent in their results, there is still no definitive research comparing organic and conventional crop yields. The best way to finally resolve this controversy would be if the USDA collected data on organic crop yields in its national surveys and censuses of agriculture. After all, they have a great crop yield dataset going all the way back to the 1860s! But—likely reflecting lingering anti-organic attitudes—the USDA has never separated out organic farms in its yield datasets. Maybe we can convince them to collect that data in the 2033 Census of Agriculture and finally lay this yield controversy to rest.

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