Some 60 percent of the hillside areas in Central America and the Andean region of South America show signs of serious soil erosion, according to a new report by the International Centre for Tropical Agriculture (CIAT), based in Cali, Colombia. Tropical hillsides, which comprise 9 percent of the world’s landmass, lose 13 billion tons of topsoil each year. CIAT is working to develop soil- and water-saving farming methods that could help boost incomes for the 200 million impoverished people throughout the world who live on tropical hillsides. The organization strives to combine the knowledge of local farmers and communities with info from international agricultural researchers and computer-based geographic information systems.