I'm wondering what can be done to help the native food sources, on the land I hunt on, grow better forage for the deer that are on the land. I'm wondering about how fertilizing various oak trees (and any others I can think of) will work. Has anyone had any experience with this? Does it work? And, to further the answers, which fertilizers would work the best?

Be very careful with fertilizers. Many granulated fertilizers are salt based and will also run off into the water table. Do soil samples and follow the directions. Your on the right track.

If you do fertilize some trees, take your post hole diggers and dig a series of holes about 8" deep just inside the drip line of the trees and put some fertilizer in each hole.