Wheat supplies in the United States as of Sept. 1 were the lowest in 14 years after a poor harvest, though the country ended the crop year with slightly more soybean supplies than expected, government data showed.

Tight supplies of wheat in the United States, the world's third-largest exporter of the grain, helped lift benchmark Chicago Board of Trade wheat futures to a three-week high and signaled higher costs for millers and bakers ahead.

Stressful crop weather in Canada and Russia, the world's top wheat supplier, has further restricted wheat supplies globally.

"Supplies of quality milling wheat are tight in the world, and today's numbers reinforce that fact," Arlan Suderman, StoneX chief commodities economist, said in a note.

U.S. farmers produced 1.65 billion bushels of wheat in 2021, down from 1.83 billion a year ago, according to the U.S. Agriculture Department's small grains summary report.

Domestic wheat stocks on Sept. 1 stood at 1.78 billion bushels, USDA said in its quarterly stocks report, the smallest Sept. 1 figure since 2007.

USDA also said that Sept. 1 soybean stocks stood at 256 million bushels, down 51% from a year ago but above a range of analyst expectations.

Supplies are being further replenished with the harvest of new-crop soybeans underway. CBOT soybean futures tumbled to $12.49 a bushel after the USDA data was released Thursday. That was the lowest for a most-active contract since December.

"We're back, historically, to (soybean) supply numbers that are a lot more comfortable," said Don Roose, president of Iowa-based U.S. Commodities.

Corn stocks were reported at 1.24 billion bushels, down 36% from a year ago but above most analysts' expectations.