One of the things that stood out in USDA's May WASDE was that total U.S. exports of wheat, corn and soybeans will again be significantly lower than those of a few years ago. The result will be a U.S. export system that will be throttled back to the idle position. It will also mean the rail transportation system will have excess capacity and that shuttle train rates should trade at levels below tariff -- except, perhaps, for the harvest period. The table below shows the past six years' of wheat, corn and soybean exports.Corn certainly stands out as the big loser in this picture. There are three reasons for the plunge in corn exports: ethanol, poor consecutive corn crops and corn expansion in Brazil and Ukraine.We often hear about the loss...