I have a 50 acre hay field on my property as well. Did the same thing as you are talking about in terms of putting a food plot on a hidden back side next to some woods. I planted a mix of four seeds this last year in the plot and the deer wore it out. I mixed two types of clover, red and white(ladina), I then mixed alfalfa, and chicory. Alfalfa was 10 pounds per acre, Chicory 3 pounds per acre, and both cloverw were 4 pounds per acre. You can get these numbers from any seed dealer. I play with mine a little, by adding more of some and less of others. The whole thing cost me less than 40 dollars an acre. Not too bad I guess for something that you don't have to plant every year. Hope this lasts about 4 or 5 years actually. Hope that helps a little maybe.
Hunting, fishing, drawing, and music occupied my every moment. Cares I knew not, and cared naught about them. --John James Audubon