What should I plant to attract turkeys?  Already have lots of oaks and a nearby water source.

I'm no expert, but I am a guide in Wisconsin, primarily for turkeys in western WI.  I have thought about planting for turkeys and here are my thoughs.

A strip of small gravel right next to the food sources so they don't have to go far for their grinding source.  Keep the gravel smaller than peas.

A spot for wallowing.  An area near the food of fine dust or sand so the turkeys have a place to wallow.  

For springtime, use something that greens up fast and succulent like clover red or white.  If you have equipment to do some tilling, throw out some oats as soon as the ground is warm enough.  This will help in late season.  Turkeys love oats when they are a couple of inches high.

Depending on how much land you have, corn is always a good bet.  You will lose alot to every other animal in the woods, but corn is good stuff.  It will help them through the winter and hold them till spring if you plant enough.

I always open the crops of turkeys to see what they are eating and it gives good insight on where to hunt.

Hope this helps.

Oh yeah, don't hunt over your food plot.