Chicago soybeans rose for a second session on Wednesday, remaining close to a two-year peak due to concerns over a dry growing-season in the U.S. Midwest and following crop losses in Argentina.
Corn dipped after climbing for the past two days, while wheat edged higher, recouping some of the losses suffered in the last four sessions of decline.
The Chicago Board of Trade most-active soybean contract had climbed 0.3 percent to $11.73-1/2 a bushel by 0215 GMT. The market climbed to a two-year high of $12.08-1/2 a bushel last week.
Corn gave up 0.2 percent to $4.35-3/4 a bushel and wheat added 0.1 percent to $4.85-1/2 a bushel.
Forecasters said the La Nina weather pattern would result in dry weather across much of the U.S. Midwest, which could reduce corn and soybean production.
"The Australian Bureau of Meteorology is calling for 50 percent chances of La Nina weather which is good for crops in Australia, India and other parts of Southeast Asia," said Phin Ziebell, agribusiness economist at National Australia Bank.
"But it means less favorable conditions for the United States and South America which is supportive for corn and soybeans."
Earlier this year, unseasonal rains across Argentina's soybean belt caused widespread crop damage. Brazil, the world's second largest corn importer, turned into an importer after lower production due to a drought.
Corn has rallied despite relatively strong crop condition ratings. The U.S. Department of Agriculture late Monday rated 75 percent of the U.S. corn crop as good-to-excellent, unchanged from the previous week and above an average of analysts' expectations for 74 percent.
Rain is needed in parts of the eastern Midwest and the Mississippi River Delta.
The wheat market has faced pressure from ample world supplies and expectations of a bumper harvest of the U.S. winter crop.
The USDA said the U.S. winter wheat harvest was 11-percent complete as of Sunday, up from 2 percent the previous week.
Commodity funds were net buyers of CBOT futures contracts on Tuesday and net sellers of wheat. Trade estimates of fund selling in wheat ranged from 4,000 to 8,000 contracts, and in soybeans from even to net sellers of 5,000 contracts. Funds were seen as net sellers of 16,000 corn contracts.