Argentina's President Cristina Fernandez de Kirchner shake hands with supporters after a planned rally by trade unions and social groups to back her in Buenos Aires April 1, 2008. Farmers nationwide continue to man roadblocks to protest a tax hike on soy exports causing food shortages and disrupting grains exports. The march comes a week after thousands of middle-class Argentines banged pots and pans in the capital's streets in support of the farmers. REUTERS/Marcos Brindicci (ARGENTINA)