Farmers harvest wheat in Zaozhuang, East China's Shandong province in this June 13, 2012 file photo. [Photo/Xinhua]

BEIJING -- The output of summer grain in China reached 129.95 million metric tons this year, up 3.56 million tons, or 2.8 percent, compared to last year's output, the National Bureau of Statistics announced Tuesday.

This year's output reached a level not seen since 1997, an NBS official said.

The official attributed the output growth to the stability of acreage for growing grain crops and better yields per unit area. The total acreage for growing summer grain stood at 27.58 million hectares this year, up 0.1 percent year-on-year; meanwhile, the yield per hectare reached 4,713 kg per hectare, up 2.7 percent.

Summer grain crops mainly include wheat and early rice in China.

Government data showed that China's grain output rose to a record high of 571.21 million tons in 2011. The figure represented a year-on-year increase of 4.5 percent and marked the eighth consecutive year of growth for the country's grain output.