China's Ministry of Water Resources (MWR) said on Tuesday that it has added 400 counties to a list of those whose irrigation facilities will be improved in small-scale projects to boost farmland productivity.

The addition takes the total number on the list to 1,250 key counties, covering 78 percent of China's arable land and accounting for 86 percent of its total grain output, the MWR said in a statement on its website.

Chen Lei, minister of the MWR, said that lack of investment in China's water conservation projects in recent years has resulted in facilities falling into disrepair and farmland productivity being reduced.

"Including counties on the list for improving small-scale irrigation facilities is conducive to raising overall efficiency of facilities and boosting their resistance to natural disasters," Chen said.

The first improvement project took place in 2009. By the end of September of this year, those listed counties had increased the acreage of adequately irrigated farmland by 19 million mu (about 1.27 million hectares), and improved irrigation for 28 million mu of farmland, according to data from the MWR.