Since you can bury corpses, i thought in my mind: "why can't i bury my bag filled with guns?" At the moment, if i'm not wrong, you can actually bury items but you need a body in order to do that. I think it would be a very useful feature principally for the multiplayer, just imagine a group of rival survivors raiding a safehouse and ending up interrogating another survivor about the location of their weapon stash, or simply having your important items buried in an unknown zone. Though, as a debuff, certain items would deteriorate because of them being buried 3 meters underground.
Also, my friends buried my dead character and my favorite gun yesterday, which proves that not only this could be used as a PvP function but even as a roleplay feature! Funerals my friends, funerals.