Train your dog to chase it away for a few days and it will eventually move on. Some people use an electric fence. Some encase the corn with chicken wire and bury it under the ground too to keep them from digging under. I have a small patch of corn and I used some of those devices that are meant to scare cats away. It activates when it detects motion. That and the dog did the trick for me. Good luck! Coons can be a real nuisance.