Our single-engine, six-seater plane lifts off at 7:30 into a gray morning sky. Staying below heavy-looking clouds, we quickly leave Nairobi's packed urban neighborhoods. Below lie lush, green fields of coffee, tea, and pineapple. Soon the landscape begins to deteriorate. In an area of hilly farms, streams run brown as they wash away soil. Further to the north, many streams are rock dry. Kenya's desert, with few signs of life, stretches out below.
Although it is known for its soil-rich farms, Kenya is, in fact, about 85 percent arid or semiarid land. Much of that is desert. And in Kenya, as in vast stretches of Africa, deserts are spreading in ever-enlarging patches where animals have overgrazed and people have felled too many trees. A UN Food and Agriculture Organization study shows that about 43 percent of Africa's arable lands face the risk of eventually turning to desert.
A few African nations are actively fighting desert spread. And a dozen or so others are drawing up plans to do so. Some donors, especially the World Bank and the European Community - major sources of funding, are showing increasing interest in helping in this fight. But 11 years after a world conference in Nairobi at which nations pledged to tackle the very serious challenge of spreading deserts, experts admit there have been few successful projects.
But several experts on desert control said valuable lessons have been learned in those 11 years: laying lines of stones to trap moisture; planting trees as windbreaks and bushes to stabilize sand dunes and slopes; building animal pens out of growing bushes instead of chopped wood, have all proven helpful.
A key lesson, they said, is that the biggest challenge is not a lack of knowledge of successful techniques, but a lack of ``political will'' on the part of the African nations themselves and the Western world, which is the major source of funding.
``The problem is political and socioeconomic. It is not technical,'' says British ecologist Hugh Lamprey, who has worked for a number of years in the deserts of Kenya.
The Africans' lack of political will is the result of the government's fear and ignorance of the people living on these fragile lands, according to these experts. Fear, because effective action would require governments to remove people from endangered lands - at least temporarily. And it would require controlling livestock on these fragile lands. Such interference in the way people occupy and use land, says Mr. Lamprey, is the ``most likely cause of increased political instability.''
Ignorance, because African officials often drag their feet on projects to rejuvenate arid pastoral lands because they know little about the people living in these areas. Mostly nomads or semi-nomads, they are generally seen by the government as less advanced, and therefore more difficult to teach and to work with than, say, farmers. Such attitudes ``might be the biggest problem,'' says Daniel Stiles, an expert on desert control working for the UN Environment Program in Nairobi.
Kenya, host of the 1977 UN conference, has yet to adopt a national strategy to tackle the problem, says Frederic Owino, dean of forestry at Moi University in Kenya and head of a new government committee on halting deserts. There have been a number of projects that have shown ``some reasonable'' results, but they have folded because of a lack of government support, he says.
There has been a serious lack of donor commitment, Lamprey says. In 1980, a panel of experts at UNEP said it would cost $4.5 billion a year for 20 years just to get a global plan of action on desert control ``off the ground,'' Mr. Stiles says. That year, donors committed about $600 million for desert programs.
If more money were available, research has proven that the best place for it would be in small-scale efforts - carried out with local support and local labor, combined with simple farming techniques applied with sensitivity to local values and customs.
Still, says Stiles, donors have put large amounts of money into ``big projects.''
In Sudan, a very large-scale effort to reduce overgrazing by drilling many wells to spread out water resources. Instead the new water sources attracted ever-larger herds that ``devastated the range,'' he says.
Successful efforts include: A project funded by CARE in the Majjia valley in Niger. Locals planted trees as windbreaks and laid stones together along the contour lines (furrows running perpendicular to a slope) to trap silt and moisture. As a result, millet yields have increased significantly.
A Tanzanian project to reclaim land by planting trees and controlling grazing in the Kondoa district resulted in an ``almost unbelievable ecological transformation from a desolate landscape of bare ground'' to decent farm land, according to a 1985 report by the UN Environment Program.
In the l960s, with funding from the US Agency for International Development, thousands of hilly acres of farmland were terraced and crop yields increased.
A follow-up study by AID in 1983 found farmers were still getting 50 percent higher yields on the terraced lands than on the nonterraced areas. But yields had fallen from the increase experienced right after the terracing.
The terraces were deteriorating because farmers resented maintaining them. The cattle, meanwhile, were overgrazing other fragile lands, speeding the area's decline into desert.
It has become clear there are ``no instant solutions; no technical panaceas,'' in fighting deserts, according to Jeffrey Lewis, an agricultural ecologist with the World Bank in Washington.