Over two million farmers and herdsmen in China's far western Xinjiang, or nearly one fourth of the autonomous region's total rural population, are using marsh gas rather than wood for cooking, a local government official said Tuesday.

With government subsidies, 580,000 rural households in Xinjiang have built marsh gas facilities, said Azizi Keyum, director of the Xinjiang Regional Agriculture Bureau.

In 2011 alone, 80,000 households became new marsh gas users, the official told an agricultural work conference.

In the past, most of the rural households used wood for cooking and heating, often proving very detrimental to the fragile ecosystem by worsening desertification.

The regional authorities started to promote the use of marsh gas in rural areas in 2003 and have since then invested 1.03 billion yuan (163 million U.S. dollars) in the program.

In some poverty-stricken regions, each family can get 2,500 yuan (396 U.S. dollars) in government subsidy for the construction of marsh gas facilities.

The program helped to save 520,000 tonnes of coal and reduce the emission of 1.9 million tonnes of greenhouse gases last year, Azizi Keyum said. It also improved the local ecosystem by curbing deforestation and desertification.

The regional government plans to help 350,000 more rural households get access to marsh gas in the next four years, according to Azizi Keyum.