Farmers may have opened their storage bins and sold supplies to help pay for such materials as seed and fertilizer after the price recently reached a six-month high. Futures have been rising on strong demand for inventories from the U.S., the world's biggest exporter of corn.

Shippers sold 745,800 metric tons of corn for overseas delivery in the week ended March 13, up 9% from the prior seven days, the U.S. Department of Agriculture (USDA) said in a report issued March 20.

The Chicago Board of Trade (CBOT) corn futures for May delivery fell 2.5 cents, or 0.5%, to $4.85 for a quarter bushel. And wheat also declined, after reaching a 10-month high, possibly lowering demand for inventories from the U.S., its biggest exporter. Wheat futures for May delivery declined 4.25 cents, or 0.6%, to $7.11 a half bushel on the CBOT.