Hi Nathan,
Since your just doing this to attract wildlife, why are you using just wheat?
I'm no expert on this, bur variety is extremly important to bring in more animals and to keep them around.
You could do it a coupld of different ways. Split up the five acres into half or 3/4 acre plots and plant each one seperate with something different.
Find a good mix of seeds and do it all in a mixture of plants that will bring them in and keep them there.
For my food plot this year, I'm just putting out bird seed from Walmart. A fifty pound sack costs under $10 and should do half an acre pretty good. The bird seed has about a dozen different types of plants it grows real easy around my bird feeders.
I know that's just a wild idea I'm gonna try without knowing if it will work or not. You could try some crazy ideas too. Just have fun with it and see what works.
Across the nation, there are programs called CRP where the goverment pays landowners to plant there fields with native grasses and plants to help the wildlife. You wouldn't qualify, but you can do some searching to see what they plant and maybe find out where to get it.
I've seen some of the biggest deer and elk in CRP fields before hunting season. Of course, I've never been able to get permision to hunt those fields, but I know for a fact that wildlife use them allot!!!
Good luck,
Eddie