Based on what you've said, I would set up in or near the field where they enter while it is still dark, maybe set up a pop-up blind. If you do bump them from the roost going in, there is a very good likelihood they will regroup close to the roost tree.

If they make it to the field and you aren't close enough for a shot, calling may or not work to bring them in, but it's not a given. I would try to scatter them, either by running full speed at them and yelling like a madman, or by firing a shot over their heads (obviously, you would want to make sure you aren't pointing your gun in the direction of someone's house, a treestand with a bowhunter in it, etc). They will most likely regroup in the woods closest to where they were scattered from.

Good luck & be safe!