Turkeys are broad feeders... alot of the time when you see them in green fields, they are feeding on worms and insects and not the green shoots... but tilling and planting freshly over-turned soil can be a good attractant... oats, rye and wheat are good options as are various other grains and bean crops. You will find that the birds forage naturally throughout the woods more than out in the open... they are just more visible in the open.