I agree with Nick's approach, at least that's what has worked for me. Have a good idea about trails into and out of the corn and what's at the other end (cover, bedding area, etc.). Then when the farmer starts combining . . . be there! You don't have to be set up right on top of the field but you need to be on an exit trail. If you scout it and bump deer pay particular attention to the way they leave the field and head into the timber. This has been a great setup for me in the past. Good Luck!