The Bush administration has just signed a $190 billion agriculture bill that could put millions of African farmers out of business. Government officials and independent economists say the big subsidies doled out to U.S. farmers will contribute to global overproduction of wheat, corn, cotton and other basic craps. That, in turn, will drive down world commodity prices, making it more difficult for small, unsubsidized, Third World farmers to compete. African nations will be particularly hard hit because agriculture plays such a big role in their economies, accounting for more than half of the gross domestic products in some.