In reference to the organic meta-analysis, Matthew asks:
What about crop genetics?? I read the actual Nature piece and no mention of seed or breeding.
Organic vs Conventional studies are often flawed in that they ignore that most organic farmers are using seed bred for conventional systems … The first axiom of breeding is to breed in area of intended use, and organic environments are quite different than conventional. Research from Washington State University shows evidence that when organic farmers used wheat seed that had been selected in organic systems for multiple generations there is as much as 20% increase in wheat yields, compared to when they plant conventional seed.
I think this is the research referred to.