You've heard the line often -- organic farming can't feed the world because it is so inefficient, producing 50 percent less than conventional methods. Then you hear the kicker -- "that's why it's only for rich people."

As Tom Philpott over on Mother Jones points out, there's been more than a few studies exploding this myth. He links to a couple, but one influential one he didn't mention was published in Science a number of years back -- a long-running Swiss study I talked about here in relation to energy use. 

Now comes yet another, from the Leopold Center at Iowa State University, which found that yields of conventional and organic farming were largely the same in a long-running trial.  

Averaged over 13 years, yields of organic corn, soybean and oats have been equivalent to or slightly greater than their conventional counterparts. Likewise, a 12-year average for alfalfa and an 8-year average for winter wheat also show no significant difference between organic yields and the Adair County average.

What the study also found was that organic fields were far more profitable, because of the premiums paid for the crops as well as lower costs for chemicals and fertilizers. (An early study looking at this was carried out by the University of California Santa Cruz back in the 1990's on organic strawberries -- it too found organic more profitable). 

This point is crucial, for another argument often heard about organic is that rotations mean far less production of a particular crop (you can't grow corn every year for instance). For a farmer, however, that doesn't matter. What matters is making enough money to keep farming the next year. Rotations are profitable in another sense as well -- they prevent depletion of soil nutrients. 

I don't expect this yield debate to be resolved anytime soon, but in many ways it's beside the point. Yield and production won't alone solve world hunger. India, which was ground zero for the Green Revolution, currently has a malnutrition rate for children under 5 of 48 percent. That's double the rate in sub-Saharran Africa which missed out on the Green Revolution. Figures like that have nothing to do with yield. They have everything to do with policies that bring food to people who most need it.