I saw an episode of "The Bucks of Tecomate" one evening and they discussed this during "The Management Minute". They do that during every episode and discuss QDMA. They were creating mineral sites in conjunction to their food plots. They dug a hole about a foot deep and wide enough to entrench a tray about the size of one used to buss tables at a restaurant. They dumped in somemineral stuff, mixed it around with the dirt, and then covered it back up. They then spread a little corn over the top of it to attract the deer to that area. I assume the tray was used to keep the minerals from soaking too deep into the soil. But that says something about mineral sites when one of the poster-boy ranches of QDMA uses them right next to their food plots. That would tell me that mineral sites definitely have some merit.