The coming new year brings intensified shipping difficulties for barge operators on the stretch of the Mississippi River just south of St. Louis. With ice on the river's northernmost stretch reducing water levels already seriously affected by the drought, traffic on the nation's largest waterway could come to a halt by Friday of next week. "While the drought is at the core of the current issues on the Mississippi, this situation also highlights the dire need for infrastructure improvements," said National Corn Growers Association Chairman Garry Niemeyer, a grower from Auburn, Ill. "At NCGA, we have been pushing for upgrades...