Switchgrass might be a good idea. The Western countries produce too much grain anyways, so converting high-input grain lands to low-input grass might actually make some profit for farmers, without needing subsidies. You might be able to extract a protein concentrate from the grass, too, depending on how you make it into fuel.
The excess grain production has politcal effects, too, because prices are depressed. This puts farmers out of business, so in certain countries they might choose to grow drugs instead, which supports criminal gang activity around the world (terrorists).
Growing grass also causes almost zero soil erosion, so it's more sustainable. I'm not sure of the economics, though.