Over half of the 696 cities and counties under a national monitoring program experienced acid rain last year due to sulphur dioxide pollution, the administration said in a report.

"The effects of acid rain on China is going to be much worse than in the United States and Europe when they had acid rain problems in the 1970s," Paul Harris, a China expert monitoring the nation's environment from Lingnan University in Hong Kong told AFP.

"China's soils are already in bad shape after being depleted following centuries of farming. Soil scientists will tell you that things are already on the edge in China."

Deteriorating soils will mean the loss of the protective vegetative cover over croplands, which eventually could lead to desertification as winds and rains further erode planting areas, he said.

"What acid rain means is that chemical reactions are taking place. These reactions are having different effects on different types of soil. Although you may have an unsure outcome, it is going to make things more difficult for farmers," Harris said.

"Forests could also be impacted and China is already having problems with forests and have banned logging."

China's farmlands are already shrinking due to rapid urbanization -- a phenomenon that is threatening the nation's capacity to grow food, Yang Jian, a senior official at the Ministry of Agriculture said on Friday.

"The amount of land dedicated to grain production is expected to continue shrinking in the years ahead, but (farmlands) will still have to produce a minimum of 500 million tons to feed China in 2010," the official said.

With shrinking acreage, falling water tables, environmental degradation and a growing population, some grain experts have predicted that China will remain a net food importer for the coming decades.

"If China does not take effective measures to curb rising coal use, then the acid rain will get worse as the economy grows and people get richer and buy even more electric appliances and vehicles," Friend of the Earth's Lau said.

"China needs to move into alternative energies like wind power, use more natural gas which is cleaner than coal and implement desulphurization technology at energy plants."