By ROBERT GEHRKE Associated Press Writer WASHINGTON (AP) -- A severe drought has prompted the federal government to open reserve land in seven states for emergency grazing. "The extreme drought has devastated many farmers and ranchers, especially in Western states,'' Agriculture Secretary Ann Veneman said Wednesday in announcing she would allow grazing on acreage held as part of the Conservation Reserve Program. The program pays farmers and ranchers not to use portions of their land that are susceptible to erosion or have other wildlife or vegetation concerns. Wednesday's announcement will allow ranchers in Colorado, Kansas, Montana, Oklahoma, Texas, Utah and...