Chicago soybean futures slid for the first time in 12 sessions on Wednesday, although losses were curbed by strong Chinese demand and dryness hitting the U.S. crop.
Wheat fell for a fifth consecutive session, while corn slid after two days of gains.
"China's state-run companies are buying U.S. beans to build food reserves," said one Singapore-based trader. "That has been the key factor driving prices higher.
The most-active soybean contract on the Chicago Board Of Trade lost 0.4% to $9.69 a bushel by 0235 GMT, after climbing to its highest since June 2018 at $9.77 a bushel on Tuesday.
Wheat slid 0.1% to $5.43-1/2 a bushel, trading near a two-week low hit in the previous session, while corn shed 0.6% to $3.59-1/2 a bushel.
China has stepped up purchases of U.S. farm goods in recent weeks, taking soybeans, corn and meat.
Condition ratings for U.S. corn and soybean crops declined slightly during the last week, the U.S. Department of Agriculture (USDA) said on Tuesday.
The USDA rated 61% of the corn crop in good-to-excellent condition in its weekly crop progress report, down 1 percentage point from the previous week and matching an average of expectations in a Reuters survey of 10 analysts.
Soybean ratings declined to 65% good-to-excellent, also down 1 point from a week earlier, while analysts on average had expected a 2 point decline.
Rains over the last 10 days have helped revive Argentina's drought-hit wheat crop and improve prospects for corn planting later this month, with Southern Hemisphere spring showers expected ahead, analysts said.
Commodity funds were net buyers of CBOT corn, soybean and soyoil futures contracts on Tuesday and net sellers of wheat and soymeal contracts, traders said.