Chicago Board of Trade (CBOT) grains futures closed mixed on Tuesday with the corn and soybean prices plunging due to higher official crop estimates.

The most active corn contract for December delivery dropped 6 cent, or 1.68 percent, to 3.515 U.S. dollars per bushel. December wheat delivery rose 7.25 cents, or 1.67 percent, to 4.42 dollars per bushel. November soybeans fell 9.5 cents, or 0.99 percent, to 9.505 dollars per bushel.

The U.S. Department of Agriculture (USDA) on Tuesday released its monthly report on domestic and world agricultural supply and demand. The USDA September crop report was deemed as bearish as it adjusted the U.S. corn and soybean yields upwards.

The USDA also pegged U.S. 2017-2018 corn stocks at 2.335 billion bushels compared with its August estimate of 2.27 billion.

For soybeans, the U.S. ending stocks are now estimated at 475 million bushels, compared with the average analysts' estimate of 442 million bushels.

The U.S. wheat ending stocks were estimated at 933 million bushels, the same as last month.

However, the USDA adjusted downwards its world wheat ending stocks to 263.14 million tons. The new wheat forecast pushed its futures higher, prompting a 1.69 percent increase.