Agriculture secretary estimates 10 percent of corn , 20 percent of soybeans lost . Remaining plantings will show reduced yields , official says . Some agricultural losses will not be covered by insurance . President Bush tours flooded areas by helicopter , for safety .
Agriculture secretary estimates 10 percent of corn , 20 percent of soybeans lost . Remaining plantings could show reduced yields , official says . Some agricultural losses will not be covered by insurance . President Bush tours flooded area by air , promises help .