My buddy has shot several deer in food plots no bigger then a full size truck! These were fall plots that were planted about 3 weeks before the season though. Also, 3 deer were shot on my land last year out of the same stand over an atv trail with clover planted in it (i passed on another). they devoured that stuff!!!

I've never had a plot as big as 1/2 acre. Mine are more 'hunting' plots rather then for sustaining the herd.

I'd recommend going small on your first attempt anyway,takes most people a few tries before they find out what works.