Like Ray said, "Test your soil." I've been planting foodplots for years and the single most important thing to do is test your soil. Without giving your foodplot the nutrients it needs and not what you think it needs you will just be wasting your money. The one thing I learned is when it comes to liming your fields, it was a LOT cheaper to have someone do it for me and a lot less agrivation. DON'T skimp on the lime!!!!!!!
Good luck,
Brian