I think James is really behind the curve on this one. I'm all for producing more, better food and surely there is some truth to the kinds of assumptions made at midcentury about the importance of rising productivity of the land for the support of us all on Spaceship Earth.
But, like democracy and socialism, the principle of increased food productivity can easily be corrupted in practice. And, as many scholars have pointed out, the idea of "improvement" and rising yields is only socially beneficial if those increased yields are somehow more widely distributed. If they are locked up in a commodity culture, it does few people any good--particularly people thrown off their land by market reforms which make food so cheap it can't be sold, but still too expensive to buy without a job. I can kind of understand the principles James is espousing, but I'm much more on board with Alan above. If the choice is between increased yields or decreased commodity farming (i.e. more aid for subsistance agriculture and mandated land reform) I'd have to side with the latter in the current era. I think Michael Perelman posted this link to his list a few months ago; either way, Raj Patel seems a good source in this debate.
http://rajpatel.org/2010/02/15/green-revolution-may-have-caused-more-harm-than-good/
I'm working on a book review on his book "Stuffed and Starved" which is a good readable polemic on this issue.
s