BEIJING, Jan. 5 (Xinhua) -- Chinese Premier Li Keqiang on Monday said protecting farmland would ensure the country's grain supply.

For a country with such a large population, China has a shortage of farmland and the "red line" must be preserved, said Li.

Protected farmland, also known as controlled environmental agriculture, refers to farming with intensive facilities, such as green houses and aquatic farming. Protected agriculture is necessary and supervision should be stepped up and violations on land uses should be punished, Li said.

Local governments should strictly protect farmland alongside rural land reform and urbanization, Li said.

Although the country has a red line on its cultivated area at 120 million hectares, pressure on arable land is still great, mainly due to rapid urbanization.