Wheat, corn and other grains may be the staff of life at the world's dinner table but when it comes to international trade they're more often the stuff of strife. U.S. farmers struggling to stay afloat financially see exports as the answer to their problems. But they're locked out of some of the worlds most lucrative markets. Trade barriers are one reason Minnesota farmers say they're in a crisis, and many have used government aid and creative financing to balance the books.