A version of this post originally appeared on U.S. Food Policy.

Photo by Alternative Heat.

The journal Nature recently had an interesting meta-analysis -- or quantitative literature review -- about yields from organic agriculture. It's called "Organic farming is rarely enough," and the accompanying summary says, "Conventional agriculture gives higher yields under most situations." This is probably true.

Yet even environmentalists are overreacting to the study. A recent article by Bryan Walsh at TIME magazine's Ecocentric blog is titled, "Why Organic Agriculture May Not Be So Sustainable."

The evidence Walsh presents fails to support the headline, though the article does begin with two good points: Organic agriculture does often produce less food per acre (see the Nature article above). And environmentalists should care about efficiency. Getting more output for lower resource cost is good environmentalism.

Mostly, though, Walsh repeats common overstatements of the advantages of conventional agriculture. He writes, "Conventional industrial agriculture has become incredibly efficient on a simple land to food basis. Thanks to fertilizers, mechanization and irrigation, each American farmer feeds over 155 people worldwide."

But environmentalists discussing conventional agriculture should also remember several key themes.

The USDA says to eat more of this stuff.Every five years, the USDA formulates new dietary guidelines -- advice for Americans on what to eat. And every five years, the guidelines are greeted with a chorus of derision. Critics like Michael Pollan and Marion Nestle have long argued that the agency backs away from directly challenging the food industry -- instead of focusing on actual food, the agency fixates on the vague concept of nutrients. For example, rather than "eat less meat," the agency has been more inclined to trot out abstractions like, "reduce consumption of saturated fat." In that …

The New York Times published a front-page exposé by Michael Moss on Nov. 6 about the federal government's efforts to get us to eat more cheese, even working with Domino's Pizza to make it happen. (Grist's Tom Philpott lauded it here.) Could this be Dairy Management's next campaign?The government's semi-public commodity checkoff programs are a big deal, collecting more than $600 million each year to promote a variety of products [PDF]. These programs support many advertising campaigns you may know, for example: "Beef. It's what's for dinner," "Pork. The other white meat," "Ahh, the power of cheese," and "Got milk?" …