Nothing brings in the turkeys like a cut field (of any kind) fresh spread with manure. Atleast where i'm from.
On a serious note I've heard that clover works as does chufa or a combo of rye, wheat, and oats. If you have aoks around and add in some strips of corn and/or soybeans then it will work year round, here the plots for deer will work for turkeys.
If your just thinking about the spring they need protein. thats insects and seeds (hence the reason they love fresh manure). I've never seen a dairy farm that did'nt have a strong population of turkeys. Food plots in the woods away from farms is a different game.