GRAINS-Corn and soybeans fall as rain seen helping US crops, wheat firm

By Michael Hogan

HAMBURG, July 21 (Reuters) - Chicago corn and soybean futures fell on Monday on forecasts for crop-friendly rain in U.S. grain belts this week.

Wheat was firm as slow farmer selling of Russia's new crop could transfer export sales to the United States.

Chicago Board of Trade most active corn Cv1 was down 0.3% to $4.26-1/4 a bushel at 1130 GMT. Soybeans Sv1 were down 0.6% to $10.29-1/2 a bushel, while wheat Wv1 was up 0.3% to $5.48-1/4 a bushel.

All three contracts remain close to multi-month or multi-year lows due to ample supply.

Chicago corn futures rose on Friday on worries that excessive heat may threaten developing U.S. crops, but more showers are forecast in U.S. grain belts this week.

“Corn and soybeans are being weakened by forecasts of rain in the U.S., which is helping remove some of the fear seen on Friday about possible heat stress to U.S. crops,” said Matt Ammermann, StoneX commodity risk manager.

“Temperatures in U.S. corn and soybean production regions are still forecast to be high, but the combination of heat and rain may create a ‘greenhouse’ impact with optimal growing conditions.”

“The USDA (U.S. Department of Agriculture) report on U.S. crops later today is likely to be stable or show improvements in crop conditions.”

Soybeans were also weakened as soyoil prices BOc1 dipped from life-of-contract highs last week.

Smaller than expected Russian exports, despite the arrival of the new crop, were underpinning wheat.

“Wheat is being supported by late arrival of the Russian new crop with farmer selling still smaller than expected,” Ammermann said. "It is still unclear whether the slow selling is because farmers are cash-rich and can hold out for higher prices, or is it because there is concern about Russian new crop quality and yields?”

“Reduced Russian export flows open the possibility of a transfer of export business to U.S. wheat, which is looking cheap in export markets.”