I also hunt next to a river, and the turkeys come and go as they please. We have foodplots planted with Oats, wheat, rye, & clover. They use them in the first week or two of the season then as everything greens up they move away. So, I started putting a corn feeder in a plot thats in the center of the lease with whole corn in it. My feeder is the type you can set the feed times on. I set it for about 45 mins after daylight, then 12:00, & the last time is at about 4:30. I set the run times for 1/2 - 2 seconds depending on what I see on my game camera. The game camera will also help you make adjustments on how much to feed, when, & where you might want to start hunting. I never hunt over the corn or anywhere close to it. When I go check my camera on days that I'm hunting, I unload my gun and leave the action open just incase someone is watching the bait......