Soybeans declined on Friday, posting the highest loss since July 2005, after China canceled some contracts for buying soybean oil.
Soybean futures for May delivery decreased by 3.4 percent, 50 cents, to $14.0875 a bushel.
Soybean futures more than doubled last year after U.S. farmers planted few acres.
Soybean-oil futures for May delivery dropped by 3.1 percent, or 2 cents, to 63.33 cents a pound.
Oil prices had increased to 72.69 cents on March 4 and the futures more than doubled last year following an increase in demand for alternative fuels and cooking oil.
Chinese soybean importers canceled the deals after vegetable oil prices dropped.
Soybean oil in China declined by 5.7 percent this week.
China's soybean imports increased by 41 percent, to 3.4 million tons in January, and soybean-oil decreased by 20 percent to 150,732 tons.
China is the world's largest buyer of soybeans and vegetable oils.
Soybeans are the second-largest U.S. crop valued at $26.8 billion after corn which was valued at $52.1 billion.