"Tapping into this huge potential will help farmers raise their living standards, boost farm production and protect the environment", said Wei.

"If 1.4 tons of coal are required to make one ton of nitrogenous fertilizer, then every one percent rise in the utilization ratio of the fertilizer in China can save 2.5 million tons of coal", he said.

"Every year, China produces 600 million tons of straw and its livestock and poultry produce 2.5 billion tons of dung and droppings", he said, adding that "the waste can be used to generate a lot of clean energy".

Marsh gas currently provides 22 million rural households in China with the clean energy equivalent of 13.5 million tons of coal every year.

About 190 million households are using energy efficient cooking ranges, which saves China another 50 million tons of coal every year.

"These projects involve more people than any other energy saving project in the world", said Wei.

A "clean countryside" project initiated by the ministry in pilot areas saw 30,000 rural households improve their living conditions by treating 90 percent of household refuse and waste water and turning 90 percent of straw into energy resources.