By Julie Ingwersen
CHICAGO (Reuters) -U.S. soybean futures rose about 2% on Tuesday, buoyed by short-covering as the U.S. harvest winds down, hopes for export sales to China and uncertainty about the availability of South American supplies, traders said.
Wheat futures turned higher, rallying from early declines as traders focused on uncertainty about grain shipments from the Black Sea export corridor and worries about Southern Hemisphere crops. Corn followed the firm trend.
Chicago Board of Trade January soybeans settled up 28-1/4 cents at $14.47-3/4 per bushel after reaching $14.49, the contract's highest since Sept. 23.
CBOT December wheat ended up 20-1/4 cents at $9.02-1/2 a bushel and December corn finished up 6-1/4 cents at $6.97-3/4 a bushel.
Soybeans rose on chart-driven buying as the benchmark January contract surged above its trading range for the month of October.
"We are chasing out plenty of shorts with this move," said Terry Linn, analyst with Linn and Associates in Chicago, adding that roadblocks by protesters in Brazil, the world's top soy exporter, were also a worry.
The main access road to Brazil's Paranagua port, the country's second busiest for grain exports, remained blocked by protesters on Tuesday as supporters of outgoing Brazilian President Jair Bolsonaro protested against his narrow election loss to leftist Luiz Inacio Lula da Silva.
"The concern was that this could drag on and be impactful in terms of disrupting ag flows and exports," Linn said.
Soy production prospects remain strong in Brazil. StoneX commodity brokerage raised its forecast of the country's 2022/23 soybean crop to 154.35 million tonnes, from 153.8 million previously.
The U.S. soy harvest is winding down with 88% of the crop cut as of Oct. 30, the U.S. Department of Agriculture said. The corn harvest was 76% complete.
CBOT wheat notched a two-week high on uncertainty about prospects for grains shipped from war-torn Ukraine. Insurers are no longer offering new cargo insurance cover for Black Sea shipments through a U.N.-backed safe corridor after Russia suspended its participation, industry sources said.
Meanwhile, Argentina's government is set to announce measures to allow wheat exporters to delay agreed shipments after a major drought hammered the crop.
Dry conditions have also hampered the newly seeded U.S. 2023 winter wheat crop. The USDA on Monday rated 28% of the crop in good to excellent condition, the lowest for this time of year in records dating to 1987.