I went round and round for years with the DNR about management of the wild life areas.
Here is my rough summary.

The State has a designation for wild life areas, recreational use and wild. The recreational designate (Delaware, Killdeer, Dillon,?etc) is where the birds are released, thus no active management to improve habitat. The wild areas (Deer Creek, Big island, ..etc) are places where there is an established wild bird population and these are managed accordingly. A lot depends on the area manager, the one who seems to do the best IMHO is Deer Creek, they rotate the fields and seem to have a good mix of nesting and winter cover. Big Island seems to be the worse, they lease the high ground to crops and in wet years the birds have a hard time nesting. But some years when the weather works out there could be good hunting.

It was explained to me that there are two main reason the state leases some of the wild life areas to farming.
1. To keep the fields from reverting back to woods, (good idea and effective if rotated properly) .
2. The cost of the leases is applied to road maintenance. (not sure about this one)

I would definitely like to see the leasing program audited just to make sure that everything is on the up and up.