40+ years planting food plots in southern Al. As advised soil test a must, but if you do not plan to follow it, don't waste you time or money. I suggest you keep the plot(s) long and relatively narrow where adequate sunshine is available. Most of the ones the group I hunt with are about 1 acre, ranging from about 2.5 acres to .50 acre.
Long story short - After trying about everything out there here are the warm weather and cold weather crops that have worked the best for us.
Warm - Perennial clovers good for this zone, Sunn Hemp, RR corn, Quail Haven (planted with the Sunn Hemp to give it a bit of a chance to get going).
Cool/Cold - Tri-Mix (Grain Rye, Wheat, Forage Oats) mixed with Austrian Winter Pea and purple top turnips. We put about 1.5# of turnip per acre. Deer really hit this crop once the frost hits and the roots sugar up.
We use a planter that has multiple hoppers and can manage multiple planting depths in one pass. If you do not have access to such a machine, you can over seed the turnips and roll in with a simple cultipacker. We plant about 36 acres total. Of this about 12 stays in perennial clover. We plant about 10 acres of Sunn Hemp each year. I cannot say enough good about this crop. Deer lover it. It is very nutritious. Research this crop and I think you will be impressed. Only down side is at first frost , it is a goner!
We do not put out corn due to concerns about issues with toxic fungus.