Rice is the staple food for at least 65 per cent of the residents on the mainland which is projected to produce 190 million tons in 2010 15 million tons more than the annual average in the past five years, Vice-Minister Wei Chao'an said.

In China, food grain includes rice, wheat, corn and others.

As its farmland is expected to continue shrinking in the years ahead, China has been seeking to improve per-unit output to provide adequate food for its growing population.

The government initiated a "national super rice hybridization project" in 1996. Yuan Longping, the world renowned "father of hybrid rice," is one of the scientists behind the project.

The resulting per-hectare yield in the first two phases of the project has reached nine tons in large areas of farmland and 12 tons in pilot farms, compared with national average of 6.7 tons, Wei said.

"We must popularize super rice varieties that show stellar performance in large-scale production, ... striving to spread them to 8 million hectares by 2010, with each hectare producing 900 kilograms more grain (compared with the yield from conventional seed)," Wei said in a document made available to China Daily last week.

The ministry did not provide a forecast of an average output for each hectare of super rice-sown farmland in 2010.

If the less optimistic level of nine tons per hectare is used to calculate the yields in the first phase of research, the 8-million-hectare super paddies are expected to produce 72 million tons in 2010, representing more than one-third of the 190 million tons of anticipated rice production that year, ministry sources say.

In the past 10 years, China's arable land has shrunk by 800,000 hectares a year. The shrinking momentum sees no signs of tailing off as urbanization continues, Wei said.

The central government's incentives offered to farmers in 2004 and 2005 had helped recover 2.33 million hectares of paddies each year, meaning it's difficult to further expand the acreage for rice, he added.

In 2010, the country will need at least 500 million tons of grain, Yang Jian, director of the ministry's Development Planning Department, said earlier.

"To realize the production goal, we must mainly rely on science and technology to improve per-unit output," Wei said.

Twenty leading super rice strains will be cultivated by 2010, he said.

Despite 10 years of research and development, most of China's 40-odd varieties of super rice are strains for only a single-season harvest and could thrive only in high-yield farmlands where natural conditions are relatively good, according to Chen Yanbin, another ministry official.

The country lacks strains that grow super in farmland under other conditions, Wei said.

Furthermore, inadequate auxiliary planting and management expertise have threatened to erode the production capacity of the super rice, he added.

So instead of focusing merely on the per-unit output on small patches of test farms, where production conditions are different from real farmland, the ministry has called on researchers to pay more attention to developing super rice seed that best meets production needs and giving technical guidance to farmers, Wei said.

Between 1999 and 2005, super rice had been planted on 13.3 million hectares, increasing rice output by 12 million tons, according to ministry statistics.

Super rice strains are mainly sown in 17 provinces, autonomous regions and municipalities in South and Northeast China.