Markets traded higher overnight and opened that way this morning, but the soy complex quickly gave way. Weather threatens shipments down the Mississippi, yields in Argentina and southern Brazil, Ukraine, and other places as well. But it is still a buyers’ market.  A decent USDA Export Sales report may, in part, show the benefits of a weaker dollar. But competition remains stiff, especially in a wheat market that stays on track despite large supplies.   Moving those supplies down the major central river systems has become difficult. Low water levels are now complicated by ice, with the Illinois River nearing impassable conditions. The result is corn basis levels jumping to 15 cents/bu in some places as exporters seek to...