Concur, fertilization not very effective. You may want to determine what type oak ecosystem you are hunting in, soil type, slope, aspect, moisture, etc. White oak is the most favored of white-tailed deer. Species in the white oak group produce good acorn crops every other year providing they are not limited by weather factors such as late frost. Species in the red oak group are more sporadic. They produce good ctops every 3 to 4 years. Oaks with crowns fully exposed to sunlight produce more acorns than those partially or totally shaded. They can also cope better with insect defoliation that may kill partially or totally shaded trees. Gypsy moth has been a problem in the Harrison area. Most oaks take over 20 years before acorn production begins. As stated by Woodtick, professional forest management will favor oak mast to increase wildlife benefits. You may want to pick up the Michigan DNR publication there in the local MDNR office if you haven't already, titled "Oak,Tree of Many Faces and Values" publication #lC4009; 2/93.