Other than glassing the fields to see the best probabilities of the trails the bucks are using and having a good wind favorible access routes to your stands there isn't much else you can do. Calls/decoys may or may not work. One thing I would try is to offer to pay the farmer to leave a few spots of standing corn/beans in your favorite areas. It wouldn't take much, just six or so rows 30 yards long and that should help concentrate the deer.