DES MOINES — A district court judge has tossed Iowa grocers’ challenge of the Department of Natural Resources’ rule requiring retailers to redeem the nickel deposits on pop and beer containers.At the same time, a Senate committee weighing proposed changes to the “bottle bill” enacted in the late 1970s to reduce roadside littering was told the issue is dead for this legislative session.The Iowa Grocery Industry Association argued in Polk County District Court that the DNR did not have authority to require retailers to redeem deposit containers.