For the first time, rice grown in diluted saltwater has yielded a crop sufficient enough to be commercially viable, according to a new study by Chinese scientists. The research team led by agricultural scientist Yuan Longping, also known as China’s “father of hybrid rice,” planted 200 types of rice in spring in the coastal city of Qingdao in eastern China’s Shandong Province and then subsequently tested their resilience to saline-alkali soil and diluted saltwater; four types of rice showed particular promise. If successful on a large scale, these salt-resistant rice varieties could turn previously non-arable space into productive agricultural land.
In order to test the rice’s resilience in saline-alkali environments, the scientists pumped in saltwater from the Yellow Sea, on which Qingdao is located. The seawater was first diluted to achieve a salinity level of .3 percent, then gradually increased to .6 percent. Although researchers expected only an output of around 4.5 tons per hectare, “the test results greatly exceeded our expectations,” according to Liu Shiping, a professor of agriculture at Yangzhou University. The four mentioned rice varieties ultimately produced yields of 6.5 to 9.3 tons per hectare. While some wild varieties of rice are known to survive in salty environments, they typically only yield 1.125 to 2.25 tons per hectare.
Increased yield from salt-resilient varieties of rice could have significant economic benefits. “If a farmer tries to grow some types of saline-tolerant rice now, they most likely will get 1,500 kilograms per hectare. That is just not profitable and not even worth the effort,” said Yuan. “Farmers will have an incentive to grow the rice if we can double the yield.” The current 100 million hectares of saline-alkali soil in China, one-fifth of which could be cultivated with the right crop, also may experience significant change as farmers move onto previously unusable land. Salt-resilient rice would prove to be an asset for South and Southeast Asia as well, regions where millions of hectare are left unused due to high salinity. The team plans to refine its rice varieties and growing techniques, so that salt-resilient rice may soon become a supplemental extension of the region’s staple crop.