CBOT August soybeans settled down 14 cents at $8.87-3/4 a bushel. New-crop November soybeans ended down 14 cents at $9.06.
CBOT August soymeal slid $3.20 to $308.40 per short ton and August soyoil slipped 0.29 cent to settle at 27.99 cents per pound.
Follow-through selling weighed on prices after most-active soybeans pulled back from a one-year high on Monday, traders said.
Rains were bringing welcome moisture to crops in the Midwest, according to weather forecasters. Traders had previously worried about the risk for a heat wave threatening crops.
The USDA, in a weekly report on Monday afternoon, said 54pc of the US soybean crop was in good to excellent condition, up from 53pc last week and above analysts' expectations for 53pc.
Worries about weakened demand from China, the world's top soy importer, also hung over the market, traders said. China has reduced imports of soy to feed hogs as a fatal swine disease has spread in the country.