A reader writes:
We shouldn't even be asking the question about the relative productivity of organic farming until we've addressed the extravagant wastefulness of consuming animal-based foods rather than plants. (By most accounts, it takes from two to ten pounds of corn to produce a single pound of meat.) If you truly want to minimize the resources that go into your diet, then eat plant-centered meals and buy your food from your local farmer's market. This is food that, for the most part, would not even be grown in the absence of local demand. It's therefore a bad-faith argument that eating local, organic food is somehow depriving poor people of their share of the earth's resources.
In response to Charles Kenny, the right metric to think about agriculture isn't some binary "organic vs. industrial" conflict, but rather "small vs. large."
As Bill McKibben has argued in Deep Economy, small farms produce more food per acre while large farms produce more food per dollar. The reason, of course, is oil; we've substituted human labor with mechanical labor on those "efficient" farms in the US and the West compared to those in Africa, and thanks to the era of cheap oil and farm subsidies, we've grown accustomed to having "cheap milk" at $2/gallon.
Kenny is making a case for GMO foods and against organic methods, but the model he's advocating for is fundamentally based (even if he doesn't mention it) on a radical expansion of fossil fuels to grow crops in these areas. If diesel is already $4/gallon in the US, and thus increasing food prices (corn and oil being the two greatest ingredients in our food economy), then what happens when we start converting the Third World to our First World large-scale practicies? Providing for fair trade, eliminating subsidies and tariffs, and promoting conservation of soil and water should be the focus of our efforts in the Third World, not GMO foods and mechanization. Those things would allow farmers to avoid the growth and debt trap of expanding their farm, only to find out they need expensive machinery, fertilizer and pesticides to service their farm land, and thus spiraling down into being farm managers instead of farmers. Which is exactly what's happened in the US.
Update from a reader:
If your reader thinks milk is $2 a gallon, s/he hasn't bought milk in the last few years. Right now the price at Hy-Vee, a Midwestern chain of grocery stores, is about $4.45. Costco is $3.35. Even Trader Joe's is $3.19.
Answers.com says $3.50 is the average.