Different organic foods are of big nutrition.

Now there are over 30 organic farms in Shanghai. Organic vegetables, fruit, rice, barley, soybeans etc. are available at many local supermarkets and are being exported to other countries and regions.

Now large-scale farms with 1,000 mu or 2,000 mu are on the increase from previous small scales like 100 mu before the year 2005.

It was said sales of organic vegetables were rising each year. In the 19 local outlets, the sales volume of organic vegetable was 5 to 7 percent of all vegetables, while sales amounted to about 22 percent because prices were up to five times higher.

Most farms are in city suburbs such as Jiading, Qingpu and Jinshan, as the cultivation of organic food requires a clean environment.

"Soil to cultivate organic foods cannot have high content of heavy metal, and it needs to be some distance from roads. Shanghai has a strong road network compared to other cities, which puts restriction on the selection of farm sites." experts said.

Soil which had once been treated with chemical fertilizer or pesticides, needed three years before being used for organic crops.