BEIJING - China's summer grain output is down year-on-year for the first time after six straight years of growth, the National Bureau of Statistics (NBS) said on Monday.

Summer grain output stood at 123.1 million tons this year, down 0.3 percent, or 390,000 tons, from a year ago, NBS said in a statement on its website.

The drop was due mainly to drought in China's southwestern regions earlier in the year, which brought output in Guizhou and Yunnan provinces down by 1.69 million tons, according to the statement.