Chinese scientists report they've cultivated a high-yield, salt-resistant rice variety that boosts output to almost 2 1/2 tons per acre. Researchers from Hainan University planted 18 salt-resistant varieties on saline-alkali land along the sea coast in the city of Yancheng in China's eastern Jiangsu province and identified one variety matching the output of varieties growing on normal farmland, China's state-run Xinhua News Agency reported. Researchers inserted a salt-resistant gene from a wild plant into a normal rice variety six years ago, and after years of screening obtained the 18 salt-resistant varieties. Saline-alkali land is expanding by almost 5,000 acres a year in Yangcheng, experts said, and the high-yield, salt-resistant variety could mean enormous economic benefits by helping the world's most populous nation produce more rice. China has about 13.3 million hectares of saline-alkali soils with the potential to be cultivated, equivalent to one-tenth of the country's total farmland, data from the Chinese Academy of Sciences indicate. More than one-quarter of the world's land is saline-alkali soil and another 20 percent of farmland is at risk of salination, Wang Cailin, chief scientist of the rice-breeding program, said.