Malawi’s leaders have long favored fertilizer subsidies, but they reluctantly acceded to donor prescriptions, often shaped by foreign-aid fashions in Washington, that featured a faith in private markets and an antipathy to government intervention.

In the 1980s and again in the 1990s, the World Bank pushed Malawi to eliminate fertilizer subsidies entirely. Its theory both times was that Malawi’s farmers should shift to growing cash crops for export and use the foreign exchange earnings to import food, according to Jane Harrigan, an economist at the University of London.

In a withering evaluation of the World Bank’s record on African agriculture, the bank’s own internal watchdog concluded in October not only that the removal of subsidies had led to exorbitant fertilizer prices in African countries, but that the bank itself had often failed to recognize that improving Africa’s declining soil quality was essential to lifting food production.

“The donors took away the role of the government and the disasters mounted,” said Jeffrey Sachs, a Columbia University economist who lobbied Britain and the World Bank on behalf of Malawi’s fertilizer program and who has championed the idea that wealthy countries should invest in fertilizer and seed for Africa’s farmers.

Here in Malawi, deep fertilizer subsidies and lesser ones for seed, abetted by good rains, helped farmers produce record-breaking corn harvests in 2006 and 2007, according to government crop estimates. Corn production leapt to 2.7 million metric tons in 2006 and 3.4 million in 2007 from 1.2 million in 2005, the government reported.

“The rest of the world is fed because of the use of good seed and inorganic fertilizer, full stop,” said Stephen Carr, who has lived in Malawi since 1989, when he retired as the World Bank’s principal agriculturalist in sub-Saharan Africa. “This technology has not been used in most of Africa. The only way you can help farmers gain access to it is to give it away free or subsidize it heavily.”

“The government has taken the bull by the horns and done what farmers wanted,” he said. Some economists have questioned whether Malawi’s 2007 bumper harvest should be credited to good rains or subsidies, but an independent evaluation, financed by the United States and Britain, found that the subsidy program accounted for a large share of this year’s increase in corn production.