In shift, U.S. will focus on providing expertise, training, roads, infrastructure to boost agricultural productivity abroad rather giving emergency aid, USDA chief says. Nation is largest donor of emergency food aid - mainly crops grown by American farmers - but spends 20 times as much on food aid to Africa as it spends on programs that could boost food production. In 1980s, U.S. annual spending on African farming projects was $400 million-plus; by 2006 it had dwindled to $60 million.