Chinese Minister of Construction Wang Guangtao said Friday that the construction authority had become very alert to the abusive establishment of economic development zones during the ongoing urbanization process.

Wang vowed at a national conference in Beijing that the construction sector watchdog would adopt tough measures to protect China's valuable plowland and curb the illegal occupancy of the farmland in name of setting up economic development zones.

Statistics showed that about 6.7 million hectares of Chinese arable land, or 5 percent of the country's total, was lost to industrial development or other purposes in the past seven years, as some local governments set up too many economic development zones while excessive and duplicated projects in some sectors also resulted in depletion and waste of considerable farmland resources, noted the minister.

A latest official report showed that 3,763 out of 6,015 development zones across China have been revoked, involving land of 1,600 sq km, including 1,100 sq km retrieved for farmland.

"Farmland is the basis of the security of national food supply, and the shrinking of farmland has affected the normal economic operation and food security in the country," Wang stressed.

China has only 123.4 million hectares of arable land, or 0.095 hectares per capita and less than 40 percent of the world's average, showed the statistics.

With a population of 1.3 billion, China has always put grain security high on its policy agenda, especially as grain output has declined for five years running to reach 431 million tons in 2003, lower than the set warning line of 450 million tons.

The conflict between a growing population and limited natural resources would continue getting worse, Wang warned, urging local construction departments to strengthen the treatment and protection of the Chinese rural environment and adopt economical approaches for the use of farmland.