Natural gas fell sharply after the Energy Department said natural gas supplies rose last week. The inventory level is 5.2 percent above the five-year average. Natural gas fell 15.3 cents, or 4 percent, to end at $3.648 per 1,000 cubic feet.Agricultural contracts were mixed. Wheat for March delivery fell 5.75 cents to end at $8.855 per bushel and March corn fell 5.25 cents to $7.5875 per bushel. January soybeans rose 1.75 cents to $14.48 per bushel.