I am highly skeptical of these claims. Corn is not new. Nor is wheat. Or rye or whatever. We have records of yields pre-green revolution, pre-GMO, pre-mechanization, pre-fertilizers, etc. And they aren't that great. Yes, modern agriculture is not sustainable and we should incorporate as many organic techniques as we can. But we also should be ready to take lower yields. And that's fine. We don't need that much corn. It doesn't go to human consumption, hardly any. It goes toward animal feed and high-fructose syrup production. We can survive with less Coke and less factory farmed poultry. But we should stop romantisizing our past and treat organic agriculture as something new or magical.