Brazilian soybean farmers have asked their country to file a complaint against the United States at the World Trade Organization alleging that U.S. farm subsidies give an unfair advantage to the world's top soybean producer. Brasilia-based farm group Aprosoja says those subsidies might be costing Brazilian farmers $1 billion a year in lost business, according to Endrigo Dalcin, president of the association's local branch in Mato Grosso, the nation's top soy-growing state.