Soyabeans and wheat were narrowly mixed in choppy trade. As of 12:54 pm CDT (1754 GMT), Chicago Board of Trade December corn was up 2-1/4 cents at $3.87 per bushel. November soyabeans were up 1/4 cent at $9.16-1/2 a bushel and December wheat was up 3/4 cent at $4.91-1/4 a bushel.
Commodity funds hold net short positions in CBOT corn, soyabean and wheat futures, leaving the markets vulnerable to bouts of short-covering, especially in advance of the US Department of Agriculture's October 10 supply/demand report.
Analysts surveyed by Reuters on average expect the government to lower its forecasts of US yield, production and 2019/20 ending stocks for both corn and soyabeans.
Additional support in corn stemmed from forecasts for late-week snowstorms across the Dakotas and western Minnesota followed by a cold spell. Lows in northwest Iowa next weekend could dip to 28 degrees Fahrenheit (minus 2 Celsius).
In Iowa, the top US corn state, just 36% of the corn was mature by September 29, compared with the state's five-year average of 74%. The USDA was scheduled to release updated figures in its weekly crop progress report later on Monday. Analysts on average expected the USDA's weekly report to show the US corn harvest as 19% complete and the soyabean harvest as 15% complete. On the global trade front, US and Chinese officials meet in Washington on Thursday and Friday in a fresh effort to solve the trade war that has slashed US exports of soyabeans and other farm products to China.