Agricultural demonstration centers should focus more on grain production rather than non-edible crops and plants, China's Vice Agriculture Minister Wei Chao'an said Tuesday amid food security concerns in the country.

Wei made the statement at a seminar in Yinchuan, capital city of northwest China's Ningxia Hui Autonomous Region.

The two-day seminar focused on the development of modern agriculture and construction of modern agricultural demonstration centers in the country.

Many of China's national demonstration centers were too focused on non-edible crops and plants or tourism instead of grain production, which is a core agricultural concern, Wei said.

Agricultural demonstration centers have played an important role in the development of new technologies and crop varieties as well as improving productivity, which had helped increase grain output and farmers' income, said Wei.

However, the centers should not charge an entry fee for farmers as this would weaken the purpose of the centers, he added.

China has more than 9,000 agricultural demonstration centers in 18 provinces, municipalities or regions, totalling 1.83 million hectares, and the annual output of these centers has reached 312.7 billion yuan (45.9 billion U.S. dollars).

The ministry of agriculture released a list of 51 national modern demonstration centers in August to promote their demonstrative role.

Food security is a serious issue in China -- the world's largest producer and consumer of grain -- as climate change and limited basic resources are likely to pose great challenges in the coming years.

China's total grain demand is expected to reach 572.5 million tonnes by 2020, and to maintain a food self-sufficiency rate of 95 percent, at least 540 million tonnes of grain would be needed by then, Zhang Ping, minister in charge of the National Development and Reform Commission (NDRC) said last Thursday.