How many cycles of spikes in demand six months out does it take to develop a futures market that spikes six months out and makes planting what's going to feed t

How many cycles of spikes in demand six months out does it take to develop a futures market that spikes six months out and makes planting what's going to feed the nation in six months profitable today? Besides which, I don't see any danger in Americans starving. We export enormous quantities of food and many food crops are, when you get right down to it, substitutes. I see zero reason to continue subsiding agriculture--big, small, cash crop, heirloom vegetable, dairy, or anything else. Whether through cash, subsidized insurance, water policy, protectionist measures, or anything else. Let the chips fall where they may.