We have an outstanding turkey population on our place and I never plant to feed adult turkey. They will eat anything that does not eat them first. I focus on poults and everything else falls into place. The biggest thing for turkey is placement. Don't focus on 2021. Think long-term. The first thing you need is nesting cover. An overgrown field, clear-cut, stream banks, etc; You need roosting sized trees proximate to that nesting cover and brooding ground nearby the nesting cover. Poults are most at risk for the first few weeks. Poults can't navigate through fescue. If that is the grass you are talking about, kill it. Bunch grasses are ok. You want a short distance between nesting cover and the brooding ground without the poults being exposed to avian or other predators. So think about travel corridors. If they have to cross a logging road or something, let the banks grow up so they have cover nearby and the exposure crossing it is minimal.
90 % of a poults diet is comprised of insects. So, you are correct to focus on bugging. I like perennial clover as it greens up early and attract bugs. Next to the bugging ground, you want some kind of canopy with bare ground under it. RR beans work. I use bicolor lespedeza, but it is a non-native and can become invasive in some conditions. I have not had a problem with it, but in some areas they do. This canopy provides great escape cover and protection from avian predators. If you want to attract turkey to your place in the summer, buckwheat is a great crops for that. They bug in it and absolutely love the seed.
All of these things are great for deer as well, so I consider turkey when I decide what to plant where, but after the above is achieved, I just plant for deer as part of a QDM program. I can't think of anything I've planted for deer that turkey don't use as well. NWTF is a big advocate of chufa, but I'm not. Unless you flood for ducks or something, I can't see planting a single species crop like chufa when turkey will use and benefit from all of the things I plant for deer.
It takes several years of this kind of habitat management for hens to give up there existing nesting grounds, but in time, they learn to move to the best habitat. Don't expect immediate results.
Thanks,
Jack