Chicago soybean futures fell nearly 2 percent on Monday to give back most of their gains from an export-fueled rally in the previous session, as attention turned back to favorable crop prospects in the U.S. Midwest.
Corn fell in step with soybeans as growing conditions in the United States also remained favorable for the feed grain. Wheat edged higher as it consolidated above a near 10-year low touched on Friday against a backdrop of hefty global inventories.
The most active soybean futures contract on the Chicago Board of Trade fell 1.9 percent to $9.83-3/4 a bushel by 1204 GMT.
The contract had climbed 2.6 percent on Friday to reach a one-week high but still ended July with a 13 percent monthly loss.
Soybeans had drawn support last week from three large sales of U.S. soybeans but analysts said good signs for the U.S. soybean harvest later this year were maintaining supply pressure.
"The market is trying to breakout of this downward trend but when you look at the supply picture, there just isn't enough demand to change the fundamentals," said Phin Ziebell, agribusiness economist at National Australia Bank.
Regular rainfall in most of the Midwest and the absence of extreme heat have allayed sporadic fears about weather threats to U.S. crops.
Investors will get a new indication about the state of soybean, corn and spring wheat crops from a weekly U.S. Department of Agriculture (USDA) progress report released after the market close on Monday.
The most active corn contract fell 1.0 percent to $3.39-1/2 a bushel, having gained 1.2 percent in the previous session.
CBOT wheat rose 0.5 percent to $4.09-3/4 a bushel, having closed down 0.6 percent on Friday when prices hit a low of $4.03-1/2, their lowest since September 2006.
Despite expectations of weather damage to the wheat harvest in western Europe, notably France, big-looking crops rolling in across the United States and eastern Europe have kept global markets well supplied and export competition stiff.
In a potential setback to U.S. exports, the USDA said on Friday that unauthorized genetically modified wheat was recently found growing in Washington state.
(Reporting by Colin Packham in Sydney and Gus Trompiz in Paris; Editing by Tom Hogue and David Evans)