I suggest trying a few different types of food plots,there are perennials (plants that will continue growing and last for several years) and the others that are Seasonal and usually on last thru 1 growing period!

Plants I would suggest to plant if You want something that will last for several years and the Wildlife will be able to use almost all year long to some extent!
Clover (Ladino,White,Red...etc)
Alfalfa
Rye Grass

Plants that are usually good for a single growing Season and most can be planted in the Spring,Summer or Fall depending on which You choose and for what purpose!Here's just a few that come to mind.

Early Spring:
Clovers
Oats
Foraging Oats
Wheat

Summer:
Soybeans
Corn
Milo

Fall:
Wheat
Brassicas
Rape
Turnips
Raddishes
Sugar Beets