Forecasters expect good precipitation in several key soybean areas of Brazil over the next 10 days, which could boost crop germination and early development following a dry start to the planting season.
A protein shortfall in this year's US soybean crop has forced processors to cut the amount of the nutrient they can guarantee in soymeal, prompting concerns that animal feed costs and meat prices could rise. The low protein could also dent exports if buyers turn to higher-protein supplies from Brazil.
Expectations for continued demand from top importer China underpinned the market.
November soybeans struggled to rise above technical resistance at the 20-day and 200-day moving averages. The Benchmark January contract closed below its 20-day moving average.
Analysts polled ahead of the USDA's weekly crop progress report expect the US soybean harvest to be 83 percent complete.