The most active soybean futures on the Chicago Board Of Trade were little changed at $8.87-3/4 a bushel by 0344 GMT, having closed down 1.5 percent on Wednesday when prices hit $8.86 a bushel - their lowest since Dec. 28.
The weakness in beans came as a U.S. trade delegation began a visit to China on Thursday for the next round of negotiations to resolve a trade dispute that has disrupted U.S. soybean exports.
"The market is essentially trading on the outcome of this talks and its based on nothing more than rumour," said Phin Ziebell, agribusiness economist, National Australia Bank.
Traders also noted the prospect of farmers switching acreage from corn to later-planted soybeans because of waterlogged conditions has weighed on soybeans ahead of Friday's USDA planting estimates.
The most active corn futures were down 0.1 percent to $3.73-1/4 a bushel, having closed down 0.9 percent in the previous session when prices fell to $3.72 a bushel - the lowest since March 21.
The most active wheat futures were down 0.5 percent at $4.67 a bushel, having closed unchanged on Wednesday.
Traders continue to monitor heavy snow pack in the northern U.S. Plains which could delay planting of spring wheat if there is a sudden thaw that could cause flooding.