I'd think your best bet would be to buy the land currently used to grow alfalfa and permanently fallow it rather than trying to run a program where you pay alfa

I'd think your best bet would be to buy the land currently used to grow alfalfa and permanently fallow it rather than trying to run a program where you pay alfalfa farmers not to farm. The latter program has the obvious problem of identifying would be alfalfa farmers once no one has grown alfalfa in a while.