Chicago Board of Trade (CBOT) grains futures closed mixed on Tuesday with wheat futures falling to contract lows as technical selling pressure dragged prices lower for a fifth straight session.

Corn followed wheat downward as harvesting of a bumper U.S. crop progressed, while soybeans ended nearly unchanged.

The most active corn contract for December delivery fell three cents, or 0.86 percent, to 3.4575 dollars per bushel. December wheat delivery fell 6.25 cents, or 1.47 percent, to 4.185 dollars per bushel. January soybeans rose 0.25 cent, or 0.03 percent, to 9.8475 dollars per bushel.

In the outside markets, the Brent crude oil market is 0.20 dollar higher, the U.S. dollar is lower, and the Dow Jones Industrials are 34 points higher.

U.S. Commodities grain analyst Jason Roose said the farm markets Tuesday continue to trade in a thin trading range.

"Disappointing soybean yields and solid demand are giving the soy complex mild support. But the corn market is softer with better yields. Plus, an open harvest forecast, weak dollar, and good planting conditions in Brazil continue to give the market resistance," Roose said.