I know you don't want to but put up a gate, a camera security system (even a fake one would probably work).
Put up a "No trespassing" sign." Run an ad in the paper that trespassers will be shot and put up a sign with that message. That is legal to do in Georgia.
The ad has to run for a month at least once a year. At least it was that way in Burke County Georgia in 1984.
From that point on if there are violators you would have moving targets to improve your shooting skills.