Iowa commodity groups are part of the coalition lobbying for the fix-up of the Mississippi River’s lock and dam system. John Hoffman, president of the Iowa Soybean Association’s board of directors, says 60 percent of the U-S grain that’s exported is shipped via river barge.Hoffman says the locks need to be updated because some of the older ones are too small for the chains of barges that’re common on the Upper Mississippi. He says most of the barges are 15 barges long and have to break to get through the locks.Hoffman says there are a number of reasons it’s best to ship grain by barge, it’s cheaper than trucking, and one barge holds enough grain to fill 870 semi-trailers.Hoffman is urging farmers to lobby their Congressmen and U-S Senators to support the “Water Resources Development Act” which will be considered this summer as that bill calls for modernizing the locks and dams.