Chicago Board of Trade (CBOT) agricultural futures settled lower on Wednesday as framers sped up collection of crops amid dry weather.

The most active December corn was down 2 cents, or 0.54 percent to close at 3.6825 dollars per bushel. December wheat was down 9.5 cents, or 1.87 percent to settle at 4.995 dollars. November soybeans were down 7.25 cents, or 0.85 percent to close at 8.5025 dollars per bushel.

CBOT corn and soybeans were lower as harvest accelerated on mostly dry weather in the U.S. Midwest. Favorable weather conditions have allowed producers to speed up collection of their crops.

The return of widespread rainfall is expected across much of the Midwest beyond the next seven or eight days, but excessive moisture is not indicated.

Wheat prices plunged on Wednesday due to worries over weak demand for U.S. wheat, with additional pressure from the rising dollar, which will make U.S. wheat less competitive in international market.

"Now wheat is the one that really broke down, the demand is just weaker and weaker and it broke through the five-dollar benchmark for the December contract," said Virginia McGathey, with McGathey Commodities.