Corn and other grain prices are closing lower as traders worry about weak exports and shipping troubles along the Mississippi River.

March corn fell 14.25 cents, or 2 percent, to settle at $7.3725 a bushel Friday.

Soybeans also fell. The January contract lost 19 cents, or 1 percent, to $14.7225 a bushel.

Sterling Smith, futures specialist at Citi in Chicago, said there was continuing fallout on corn prices from the very weak export report issued by the Department of Agriculture Thursday.

Very dry conditions have also led to restrictions on the amount of cargo that can be carried on barges on the Mississippi. Traders worry that U.S. corn is already facing tough competition from lower-priced grain from South America.

Gold and other metals prices rose. Energy prices were mixed.

Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.