I can't imagine too many deer wanting to chance a tilled cornfield during daylight hours... Especially if there's been any hunting pressure (don't know when your season opened)
If it was VERY recently harvest and tilled, there will be plenty of forage for them to pick, but they'll do it after dark. You might be able to lay in wait adjacent to the field and catch some making their way to it, but it'll be awfully close to dark (if they behave like PA deer.)
The farm I hunt has 20' of clover & chicory around the hay and corn fields, and they'll graze that, working the edges, during the day, even after things have been cut & harvested, but you don't see them brave the open field except the late overnight hours, and only then if there's little to no moon.
I'd hunt the oaks as my primary, and move to a location near a corner of the cornfield for the last light of the day if I saw nothing moving all day. (last resort)