I got this recipe from the Missouri Sportsmen's Information Network and I'd like to pass it on as I have had success with it. You can buy this at your local grain elevator or feed store in town.
Ingredients: Makes 200 lbs. for about $23.00 (you can't beat that)
1 part Di-calcium phosphate (this is a dairy feed additive that comes in a 50 lb bag at around $11.00, you need one bag)
2 parts Trace Mineral Salt ( the red and loose kind without the medications this comes in a 50 lb bag at around $5.00, you need two bags)
1 part Stock Salt ( ice cream salt this comes in a 50 lb bag at around $2.00, you need one bag)
Use a 3 lb or similar size coffee can to use as your measure for each part of the mix.
Mix all together well but not until ready to use, keep ingredents separate until ready to put to use.
Dig or tear up a circle in the soil about 36 inches wide and about 6 inches deep.
Mix your mineral mixture in with the soil.
Replenish in 6 months with fresh supply of mineral, and then each year there after.