Hi,
The deer leave the trees, even though they are far away, to get to the food source. Find the nearest thick cover and see if it' s a bedding area, if not keep looking and find a bedding area or the run that the deer use to get to the feeding area. Set up there and just make sure the wind is in your favor in regards to where the deer will be coming from, not the field. You should be able to ambush them heading out to feed.
Good Luck!
Mark
http://www.buckhuntersecrets.com