Millions of acres of farmland worldwide are underused because of high salt levels. Ceres, a company in Thousand Oaks, California, has developed a genetic trait that allows certain plants to tolerate high levels of salt. Ceres uses genetic engineering to embed the salt-tolerance trait in switchgrass, a plant that has shown promise as a source of biofuel such as ethanol. The company, which received a $5 million grant from the Department of Energy in 2009, has been testing the plants in greenhouses in California. Next, it plans to conduct field trials in natural settings, with the goal of bringing the seeds to market by 2015. Ceres also plans to conduct field trials of salt-tolerant rice plants in Asia this spring.