Corn, wheat and soybean futures declined Wednesday on favorable South American weather.
Corn and soybean futures declined as the value of the dollar rises, cutting purchasing power for importers of grains and oilseeds.
Grains were mixed and soybeans were lower as investors weigh slack demand against a record net-short position.
Money managers increased bets on lower corn prices in the week that ended on March 8 amid declining demand for US supplies.
Corn and soybean sales in the week that ended on March 3 improved, the USDA said in its weekly export sales report.
Bets against rising corn prices jumped to a record on burdensome global inventories.
Wheat futures rose on signs of demand from Egypt as corn and soybean futures were little changed.
Soybeans sales to overseas buyers increased in the week that ended on Feb. 25, according to a USDA export sales report.
Speculative investors increased net-short positions, or bets that prices will fall, in corn futures to the highest level in almost a month, according to the Commodity Futures Trading Commission.
Export sales for corn jumped in the week ended Feb. 11 as dollar declines and prices fall.