The organic farm at the University of California at Santa Cruz.
Over on the Scientific American blog, Christie Wilcox set out to expose the "myths" of organic farming. Frankly, the piece was so poorly reasoned that I read it with a yawn. But people take Scientific American seriously (as they should—it's a great publication) and the piece was received with credulity on Matt Yglesias' influential blog and at my former employer, Grist. (Grist has since published a critique of the Wilcox piece by Tom Laskawy).
Since some smart people seem to be buying what Wilcox is peddling here, let's look at her central claims.
1) Organic farms are seething hotbeds of toxic pesticide use. Wilcox notes, correctly, that organic farms are allowed to use certain non-synthetic pesticides. I agree the practice is problematic. Organic farming is built on the principle of on-farm ecological balance—that crop biodiversity should provide habitat for a variety of "beneficial insects," which should in turn keep crop-eating ones under control. Use of pesticides, even non-synthetic ones, represents a breakdown of that principle, and should be avoided by organic farmers.
But how much of a problem is pesticide use on organic farms? To hear Wilcox tell it, buyers of organic food are unwittingly getting all manner of pesticide traces on their produce. To back that up, she drops this dud of a bombshell:
Furthermore, just over 1% of organic foodstuffs produced in 2007 and tested by the European Food Safety Authority were found to contain pesticide levels above the legal maximum levels—and these are of pesticides that are not organic.
Just over 1 percent, eh? That means that just under 99 percent were found to be ok. Scary! It would be interesting to see how non-organic food fared in that study; Wilcox doesn't see fit to compare the two. Meanwhile, back here in the United States, the USDA collects data on pesticide traces on produce. In 2009, reports the Organic Center, the USDA analyzed 386 samples of organic lettuce, "by far the most extensive sampling of an organic food crop for pesticide residues ever carried out in the world." Again, "just over 1 percent" of the samples contained a pesticide residue not approved for use on organic farms, the OC reports. As for pesticides approved for organic use, 78 samples carried traces of those, meaning that 20 percent of organic produce carried a residue.
By contrast, the most recent USDA data on non-organic lettuce showed that the average sample carried residues of nealy four four distinct pesticides, the Organic Center reports.
Thus, despite Wilcox's bluster, organic food is clearly consumers' best bet for avoiding pesticide traces on their food. (For more information on the pesticide-residue cocktails that coat conventional vegetables, see my analysis of Environmental Working Group's recent report on the topic.)