WASHINGTON, D.C., U.S. — China’s revisions to its grain balance sheets extending back to 2007-08 resulted in wide adjustments in world supply-and-demand estimates and forecasts for key crops as indicated in the U.S. Department of Agriculture’s monthly World Agricultural Supply and Demand Estimates report issued Nov. 8.

China’s National Bureau of Statistics (NBS) in October revised its area, yield and production estimates for corn, wheat and rice from 2007-08 through 2017-18. The USDA adjusted its world supply and demand forecasts accordingly.

The USDA noted the NBS added a cumulative 266 million tonnes to its corn production for the 2007-08-to-2017-18 period. The USDA commented, “While just over a half of the additional volume is added to stocks, total domestic consumption (throughout the period) is adjusted to reflect greater use of feed and residual disappearance and fuel ethanol.”

The USDA in its November WASDE forecast China’s 2018-19 corn ending stocks at 207.49 million tonnes, up 148.99 million tonnes compared with the October projection (made before the NBS production revisions) at 58.5 million tonnes.

The USDA forecast 2018-19 world corn ending stocks at 307.51 million tonnes, up 148.16 million tonnes from the October outlook. Without the revision to China’s projected ending stocks, the forecast for world corn ending stocks would have been 0.83 million tonnes lower than the October outlook.

The USDA in November also raised its estimate of China’s 2018 corn production to 256 million tonnes, up 31 million tonnes from the October estimate. The USDA raised its 2018-19 world corn production forecast by 30.64 million tonnes from the October outlook to 1.098.95 billion tonnes. With the exception of China, adjustments to production forecasts were minor.

Notably, there were no changes to the USDA’s forecasts for China’s corn import and export forecasts for 2018-19, at 5 million tonnes and 50,000 tonnes, respectively. China’s corn market largely is self-contained.

The USDA indicated the N.B.S. revision added a cumulative 20 million tonnes to China’s wheat production for the 2007-08-to-2017-18 period.

“Most of the increase is added to stocks, with only a small addition to feed and residual use,” the USDA commented. “Revisions were not made to food, seed and industrial use as per-capita consumption appears to be relatively stable. China’s stocks are forecast to account for over half of global wheat stocks but are generally not accessible to world markets.”

The USDA forecast China’s 2018-19 wheat ending stocks at 143.57 million tonnes, up 7.45 million tonnes from the October projection. China’s 2018 crop was estimated at 132.5 million tonnes compared with 128 million tonnes as the October estimate.

The USDA raised its forecast for 2018-19 world wheat ending by 6.53 million tonnes, to 266.71 million tonnes. Without the China revision, world wheat ending stocks would have been 0.9 million tonnes lower than the October forecast.

The USDA said the NBS revision added a cumulative 18 million tonnes to rice production for the 2007-08-to-2017-18 period.

“Most of the increase is added to stocks as rice is primarily used for food, and per-capita consumption appears to have remained relatively stable,” the USDA said. “China’s stocks are forecast to account for more than two-thirds of global stocks, which are now at a record.”

The USDA forecast China’s 2018-19 rice ending stocks at 113 million tonnes, up 7 million tonnes from the October outlook. The USDA raised its estimate of China’s 2018-19 beginning stocks of rice to 109 million tonnes, up 15.5 million tonnes from the October estimate, after the NBS revisions. The USDA also raised its estimate of China’s 2018 rice crop to 143.58 million tonnes, up 2.78 million tonnes from the October estimate.

The USDA forecast 2018-19 world rice ending stocks at a record 163.02 million tonnes, up 17.81 million tonnes from October. World rice production in 2018-19 was forecast at 490.7 million tonnes, up 2.94 million tonnes from the October projection.