One of the things Michael Pollan tries desperately to do in his books (and I presume will attempt in Food Inc.) is to make organic farming appear more efficient than conventional or GMO. This he does through various argumentative tricks, some of which I listed below in the Bad Logic post. The reality is that there is no efficiency argument to be made for organic farming, at least in conventional terms. When it comes to getting the maximum out of land relative to what went into it, conventional and GMO win every time.
So let’s change the definition of efficiency say the organic crowd. And they do, by pouring more and more context (external costs like the overall economic impact of runoff and pollution) into their equations until they arrive at numbers they’re happy with. That makes a certain amount of sense, since one of the cornerstones of the organic philosophy is that everything is connected. But of course changing the math still doesn’t change what goes on at the farm level, nor increase the total amount of food that an entirely organic system would be capable of producing.