There are exciting reasons to be optimistic about the potential of African countries to alleviate poverty and achieve food security. Granted, at first glance, prospects of reducing hunger in Africa appear to be dire or even hopeless. The continent has grown increasingly dependent on food imports, and the world's wealthy nations seem to have abandoned efforts to reverse the trend; their aid to African agriculture has fallen by 40 percent since 1980.

Yet if such numbers are an accurate portrait of African reality, why does so much enthusiasm and hope radiate from every corner of Africa by researchers involved in the "Successes in African Agriculture" project? Agricultural specialists tell stories of successful research, innovative African farmers, and small--and sometimes not so small--booms in food production. Why are these agricultural workers so upbeat?

Set conventional wisdom aside for a moment and consider an alternative portrait of African agriculture, past and present. The farmers described in these real-life stories are creative and energetic, quickly adopting promising new crops and technologies. Most of Africa's major crops are not native to the continent. Bananas arrived from Asia many centuries ago. Plant breeders today marvel at the skill with which farmers in Uganda and surrounding countries selected offspring from these plants, which do not normally reproduce through seeds. The central highlands of Africa now hold the most genetically diverse collectionof banana trees in the world, and bananas have become an important source of food. Similarly, cassava arrived on the boats of Portuguese traders and spread rapidly among Africa's farmers. By the time Europeans began exploring the continent's interior, the hardy cassava plant was already there.

More recently, farmers in Kenya, Uganda, Zimbabwe and Zambia have begun exporting large numbers of fresh vegetables and cut flowers. Milk production, meanwhile, has become the fastest-growing source of income for small farmers in Kenya. Some 600,000 small farmers milking fewer then four cows apiece produce 80 percent of the country's milk.

Perhaps the most inspiring success stories are those that describe farmers, many of them women, banding together to accomplish things that they could not do individually and which governments proved incapable of doing. Farmer groups in Burkina Faso have constructed stone dikes, capturing water and preserving topsoil. Village associations in Liberia manage local fishing rights to prevent overfishing during spawning season, and in the Sudan, traditional leaders in the Butana Region manage grazing rights and water access. One observer wrote, after a visit to some of the powerful farmer organizations in West Africa, "I was awed by what I saw."

These successful experiences represent seeds of hope. They are signals of Africa's potential. Yet they remain too isolated from each other, supported by too few resources, and beset by too many environmental and financial pressures. The world community cannot simply walk away. These seeds need to be nurtured, so they can grow to maturity, blossom, and spread further. Because as African agriculture goes, so goes the continent. Roughly 80 percent of the continent's poor live in rural areas, and even those who do not will depend on increasing agricultural productivity to lift them out of poverty.

New technologies offer great promise. For example, rice breeders have created a radically new type of rice for Africa, one that combines the hardiness of African rice with the high yields of Asian varieties. Seeds for these hybrid rice plants are now available to African farmers. As they become more widely disseminated, they could unleash a surge in rice production. Or take the fertility of Africa's depleted soil. Researchers have identified ways to nurse the land back to health, in the process doubling the size of harvests.

These stories teach two lessons. First, agricultural research produces enormous benefits, and the world's governments need to support it more generously. Second, farmer adoption of new technologies requires favorable incentives. These in turn depend on both domestic and international policies affecting farm markets and prices. Both national governments and international fora have key roles to play.

An African green revolution won't be unleashed by a few magical inventions. Many pieces need to fall into place: new technologies, better education and social services, functioning local and national institutions, communication and transportation infrastructure that allows farmers to find markets, and government policies that allow farmers to profit from their hard work. It's a tall assignment, but that's no cause for defeatism. Success is possible. In many places, it's already happening.