Mowing the grass will help. The dew in the tall grass wets their feathers so they tend to avoid tall grass until the sun dries the dew. A wet bird can't fly.
They supposedly like Chufa. I've tried to plant it with little success. They will eat bugs off of alfalfa and clover. Not necessarily a food plot item, but I've seen a hen eating seeded, dandelion heads one after another.
Are you spring or fall hunting? Each has their own techniques.