Instead of wondering how and where an agricultural product was grown, we should be asking different questions, Navin suggested: "Is it good for the environment? Can it feed people? Is it good for the farmer?" To answer those last two questions -- can it feed people and is it good for the farmer -- you have to understand yields. Land is scarce and expensive, and if organic methods require more land (because they produce fewer calories per hectare), they will drive up food costs. That's troubling in a world where hunger is a bigger problem than obesity.
The Nature report has provoked a variety of responses. In an email to Andrew Revkin, who wrote about it at Dot Earth, author Jon Foley wrote:
The bottom line? Today's organic farming practices are probably best deployed in fruit and vegetable farms, where growing nutrition (not just bulk calories) is the primary goal. But for delivering sheer calories, especially in our staple crops of wheat, rice, maize, soybeans and so on, conventional farms have the advantage right now.
I asked Stave Savage, a scientist and industry consultant who blogs about agriculture at Applied Mythology, for his reaction. He looked at the underlying studies and told me that the evidence for the claim that organic can compete with conventional methods, even when it comes to growing fruits and vegetables, is skimpy. He told me by email:
The authors ultimately come out saying that some sort of hybrid would be a good idea. On that I agree. Organic was very ahead of its time in the early 20th century by focusing on building soil quality. No-till and cover cropping achieve the same benefits without having to haul in massive amounts of compost or manure.
The problem is that many of the avid supporters of organic have no interest in anything like a hybrid or one learning from the other. There is too much emphasis on philosophical purity and about demonizing regular agriculture rather than observing how much it has changed over time.
Less than 1 percent of US farmland is farmed organically. If farmers could improve their yields by giving up chemicals and genetically modified seeds, why wouldn't they?
I'm planning to interview Laura Batcha of the Organic Trade Association this week, and I'll ask her that question. We'll also talk about the Farm Bill, the campaign to label genetically modified foods and mad cow disease. I'll report back in a few days.