My experience with both corn and soybeans is that you have to plant a lot of acreage or they will be gone. Soybeans get munched before they reach a few inches in height and corn is gone by hunting season. Corn also attracts bears here in PA and once a bear moves in on your corn plot, forget it. Deer won't hang around the predator and the bear will eat up the whole thing. And then there are the coons.
If you have a lot of ground, try Eagle beans in with a stand of corn. plug the corn planter to put in half the rows and drill in the beans. The corn stalks can act as strata for the beans to climb on. These beans will resprout from nodes after they have been browsed and stay alive and growing into late summer.
I was at a biomass gowing meeting at the USDA experimental station in Big Flats NY last year and they had a demonstration of putting canola into standing corn in the late summer. The canola overwinters and grows quickly in spring to produce seed oil which the farmer then burns in his equipment the next year. Of course I was not listening because I was looking at the way the deer had browsed this canola. I would like to try this system or do the beans - corn - canola system and really go crazy. I don't have a field big enough to do this in so maybe you could try and let me know how it works.