China’s government last week significantly boosted the country’s corn production levels for the past decade, creating a ripple effect for global stocks in the USDA’s November World Agriculture Supply and Demand Estimates (WASDE) report.

The data overhaul raised China’s corn output in 2017 to 259 million tons, a 20 percent increase from the 215.9 million tons originally reported for the crop, Reuters reported. The USDA also revised production, domestic consumption and ending stocks of corn for China...