Stanford University scientist Paul Ehrlich thought there was no chance to feed humanity.

"Hundreds of millions of people will starve to death in spite of any crash programs embarked upon now," wrote Ehrlich in his 1968 book "The Population Bomb."

But Norman Borlaug defused the bomb. Borlaug, a plant scientist born nearly a century ago on an Iowa farm, is obscure in the U.S., despite a Nobel Peace Prize. But he is widely known elsewhere as the father of the Green Revolution, which brought modern agriculture to the developing world.

The tools he still promotes - high-yielding seeds, fertilizer, irrigation, pesticides - have pushed food production in nations such as Mexico, India and China to outpace rapid population growth. But not Africa, which for reasons of infrastructure and geography missed out.

While some scientists credit Borlaug with saving millions of lives, if not a billion, some anti-biotechnology groups say he has done social and environmental harm by pushing a mechanized style of agriculture dominated by corporations.

The debate over the legacy of the Green Revolution cuts to the heart of the hunger issue in Africa. Proponents say hunger can be solved with higher yields - whether through the Green Revolution's toolbox of fertilizer, hybrid seeds and irrigation, or through the new techniques of biotechnology. Critics say hunger's root cause is poverty, and that modern agriculture, including biotech, will increase dependence on corporate-held technology.

Social changes

Toward the end of World War II, Borlaug began a high-yield wheat breeding program in Mexico, which was a net wheat importer. Within a decade, Mexico was exporting wheat.

The techniques spread to Asia. Populations did explode, but the food kept up. In India, for example, the population more than doubled between 1961 and 2001. In that time, India almost tripled its grain production from 87 million tons to 231 million tons, according to the United Nations Food and Agriculture Organization.

But the agricultural transformation also was a social one, with small farmers ceding their livelihoods to rich farmers and big corporations, said Eric Holt-Giminez, director of Oakland, Calif.-based Food First, a nonprofit organization that advocates organic farming. The Green Revolution required money for tractors, high-yielding hybrid seeds and pesticides.

"Yes, they gave high yields under optimal conditions. But only to the farmers who could make use," Holt-Giminez said. "The larger farmers immediately displaced the peasant farmers."

This social transformation never occurred in Africa, which today is characterized by organic, small-scale farming and the lowest crop yields in the world - yields that haven't risen in decades.

The Green Revolution never arrived for several reasons. First, Borlaug sought improved seeds for just a few varieties of wheat and rice; Africans farm hundreds of crop varieties. Second, with its drier terrain, Africa isn't as suited to irrigation. Finally, Asian roads in 1960 were better than African roads today; their terrible condition makes seed and fertilizer distribution difficult. Africans use the least amount of fertilizer in the world and pay the most for it.

What Borlaug couldn't get to happen the first time around, donors are attempting again. In September, the Rockefeller Foundation and the Bill and Melinda Gates Foundation announced a $150 million Alliance for a Green Revolution in Africa.

Some African leaders said they would welcome the social effects of more efficient agriculture. The meager harvests of small farms, they said, are unsustainable.

"Agriculture is a business," said Romano Kiome, a top Kenyan agricultural minister. "If you are farming for subsistence, just to live and eat, you are as good as a dead man."

Mountains of food

But for Mariam Mayet, of the African Centre for Biosafety, a South African anti-biotechnology group, Green Revolution-style agriculture is unsustainable. "How long can you throw poison on a small piece of land and grow one crop?" she asked.

Mayet uses the term "poison" because the overuse of pesticides can damage human health, and the overapplication of fertilizer can upset the chemistry of rivers and lakes and cause algae blooms that choke off aquatic life.

Borlaug said organic farming is a luxury.

"It's very confusing and very disgusting in the Third World when people come from the affluent nations and tell the Third World political leaders that they can produce the food that's needed for 6.54 billion people with organic fertilizer alone," he said in a speech earlier this year at the Donald Danforth Plant Science Center in Creve Coeur. Put plainly, Borlaug said, there isn't enough manure to go around.

There also was an environmental benefit to the Green Revolution, Borlaug said. Habitat that would otherwise have been farmed was saved.

Between 1961 and 2005, the worldwide area of land farmed for cereals barely increased. But on that same amount of land, farmers more than doubled cereal production from 800 million tons in 1961 to more than 2 billion tons in 2005. If farmers had to use the inefficient methods of 1961 to achieve today's yields, they would need an additional 4 million square miles of farmland - a field bigger than the entire U.S.

"You see that agriculture and high-yield technology are not necessarily an enemy of the environment. It can be a blessing," Borlaug said.

Still, producing more food doesn't solve hunger on its own, Holt-Gimenez said. Poverty causes hunger, he said, which is unrelated to how packed a nation's food stores are. He points to nations such as India, which has a third of the world's hungry people even as it exports food.

United Nations studies have shown that the hungry fall into two basic categories: farmers who can't grow enough food, and urban dwellers too poor to buy it.

Robert Horsch, a former Monsanto vice president who now heads the Gates Foundation's agricultural efforts, said Green Revolution-style agriculture can help both groups. Poor farmers can produce more on small plots of land. As yields rise and a "mountain of food" is produced countrywide, prices fall, helping the urban poor.

This seems to be happening in the long term: Food prices, along with hunger and poverty, have declined in the developing world.

That is, everywhere in the developing world except for Africa - the one place where the Green Revolution has not taken root.