QINGDAO -- A rice crop experiment on saline soil has beaten expectations, laying the foundation for commercialization, according to Chinese scientists Thursday.

Four types of rice registered an estimated output of between 6.5 to 9.3 tonnes per hectare, at Qingdao saline-alkali tolerant rice research and development center.

In spring, more than 200 types of rice were planted in the coastal city of Qingdao in East China's Shandong province. Diluted sea water was used on the soil to test which could survive and prosper in saline environments.

Seawater from the nearby Yellow Sea was pumped into the center, diluted to a salinity of around 0.3 percent and channeled into paddy fields, then increased to around 0.6 percent, putting the rice in a tougher environment.

Researchers had expected an output of around 4.5 tonnes per hectare, said Wang Kexiang, chief of the technology department of the center.

"The test results were way above our expectations," said Liu Shiping, professor of agriculture at Yangzhou University, who is reviewing the results.

Certain types of wild rice that have not yet been manipulated by humans, can survive salinity, but they typically have a yield of between 1.125 to 2.25 tonnes per hectare.

Yuan Longping, who led the experiment, said that he was very satisfied with the results. Known as China's "Father of Hybrid Rice," Yuan helped establish the Qingdao center in October 2016.

Rice is China's staple food, and the mission of the center is to develop commercially viable rice tolerant of saline and alkali soil.

INCREASED HEALTH BENEFITS

Yuan said the increased harvest may encourage farmers to grow more such rice in the future.

"If a farmer tries to grow some types of saline-tolerant rice now, he or she most likely will get 1,500 kilograms per hectare. That is just not profitable and not even worth the effort," Yuan said.

"Farmers will have enough incentive to grow the rice if we double the yield," Yuan said.

Increased productivity could also change the landscapes. China has about 100 million hectares of saline and alkali soil, of which about one fifth could be cultivated, Yuan said.

Millions of hectares in humid regions of South and Southeast Asia are technically suited for rice production, but are left uncultivated or have very low yields because of salinity and problem soil, according to the international rice research institute, the leading research organization dedicated to reducing poverty and hunger through rice science, based in the Philippines.

Breeding varieties with in-built salt tolerance is considered the most promising, economical and socially acceptable approach, said the institute.

Theoretically, rice on saline soils carries added benefits. Calcium and other micro-elements are abundant in salty environments, so the rice will be rich in micro-elements.

It is also difficult for pathogenic bacteria to grow on saline and alkaline land, so rice grown there is less likely to be exposed to pests, hence, there would be less use of pesticides, said Dr Yang Hongyan with the center.