Chicago Board of Trade wheat and soybean futures all turned higher on Tuesday as a stubbornly bearish market gained support from weather issues in Brazil and a flurry of short covering as funds shift out of their huge net short positions.

Hefty global grain supplies, competition for export business anchor prices
Corn, soy firm ahead of USDA data
Corn drifted upward, soybeans declined
Exports the most likely category to see changes, analyst says
Most analysts expect USDA to lower its Brazil harvest estimate
Brazil soy harvest running ahead of schedule compared to last year
Slowing Chinese demand also weighs on prices
Weekly soybean exports on lower end of expectations -USDA