CBOT grain prices also plunged as crop-favorable rain fell over the weekend in the U.S. Midwest.
Brokers estimated that funds sold 6,500 contracts of soybeans,5,200 contracts of wheat and 12,000 contracts of corn.
Following a two-day economic and trade consultations between high-ranking Chinese and U.S. officials in Beijing, the Chinese side issued a statement on Sunday.
"To implement the consensus reached in Washington, the two sides have had good communication in various areas such as agriculture and energy, and have made positive and concrete progress while relevant details are yet to be confirmed by both sides," said the statement.
"All economic and trade outcomes of the talks will not take effect if the U.S. side imposes any trade sanctions including raising tariffs," the statement added.
The lack of assurance that the U.S. would not raise tariffs against Chinese goods left CBOT traders disappointed, said market observers.
As a result, CBOT soybeans, a key agricultural product the U.S. exports to China, slid sharply.
Corn futures also suffered double-digit losses as rain fell over the weekend in the Midwest areas and temperature rose, favorable for corn growing.
On Monday, the most active corn contract for July delivery fell 10.75 cents, or 2.75 percent to settle at 3.8075 dollars per bushel. July wheat delivery went down 18 cents, or 3.44 percent to close at 5.0525 dollars per bushel. July soybeans were down 19.5 cents, or 1.91 percent to settle at 10.0175 dollars per bushel.