I live in a part of the country that grows corn and soy beans. Farmers are sticking to their normal crop rotation between corn and beans, even though corn is pushing 6 dollars a bushell in the area beans can regularly be sold for 13 or more. Farmers are, however, pushing more and more marginal land into row crop production. Land that may have previously been used for hay or grazing is now being irrigated by large organizations and put into row crop, even where this land is getting half the yield of normal row crop land it is still turning a profit.
We are not quite at the point that we are planting every nook and cranny with corn, not yet anyways, lol.