BEIJING - Arable land contaminated by heavy metals across China will be withdrawn from agricultural production, said a senior Chinese agricultural official on Wednesday.

Agricultural land with high levels of heavy metals will no longer be used, said Chen Xiwen, deputy director of the central agricultural work leading team, the top agriculture authority.

Farm land near river sources, especially drinking water sources, will also retreat from production if use of fertilizers and pesticides may cause pollution, he added.

China will start pilot restoration of contaminated farmland this year, according to the "No 1 Central Document", the first policy document of 2014, issued on Sunday.

A comprehensive plan to address prominent agricultural and environmental obstructions to sustainable development is also in the pipeline.

The "No 1 Central Document" stressed improvement to the national food security system. In recent years, excessive use of fertilizer, pesticides and plastic film combined with industrial heavy metal and chemical pollution, have hindered the sustainable development of agriculture, said Zheng Fengtian, an agriculture professor at Renmin University of China.

Excessive and improper use of resources has also affected food safety, he added.

China has an estimated 50 million mu (3.3 million hectares) of moderately or severely polluted soil, most of which is in developed and grain-producing regions, said Wang Shiyuan, vice minister of land and resources in December.

The polluted areas account for about 2 percent of total arable land which stands at some 2 billion mu.

Every year, some 12 million tons of grain are polluted by heavy metals in the country, according to the Environmental Protection Ministry.