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.

Agriculture Minister Han Changfu warned last month that severe drought in the southwest and the extremely cold weather in the north earlier this year had damaged the country's summer grain harvest.

In April, the government unveiled funding plans worth more than 2.4 billion yuan to support the summer grain harvests, which account for about one quarter of China's annual food yield, according to the Ministry of Agriculture.

Summer grain output rose six years in a row to top 123 million tons last year, 2.6 million tons more than the previous year.

Despite a slight expansion of the planting area, which rose 0.1 percent to 27.42 million hectares, the yield per hectare this year dropped 0.4 percent year on year to 4,48 tons per hectare, NBS said.