IT MUST be true. We’ve been told it so many times. The over-farmed and
overgrazed soils of Africa, especially on the fringes of the Sahara, are losing
their fertility and eroding away. As the population grows, poor farmers are
mining the last goodness from their soils. Their animals graze the grasslands
away to nothing and the desert sands move in. Environmentalists say it;
development economists say it; politicians say it; soil scientists say it.
“An area the size of Somalia has become desert over the past 50 years. The
same fate now threatens more than one-third of the African continent,” says the
UN Food and Agriculture Organization, adding that “the main cause is
mismanagement of the land.” Its sister body the UN Environment Programme claims
that 900 million Africans face starvation as their soils crumble away. UNEP
masterminded a UN Desertification Convention in 1996 in an effort to reverse the
trend.
But out in the shimmering heat of arid Africa, where tens of millions of
farmers scratch a living from the soil, new research suggests that this
apocalyptic vision is little more than a mirage. Farmers are finding ways to
intensify their farming methods without destroying their soils. Farm yields are
often up, not down. Soils are often getting better, not worse. Fast-growing
populations continue to be fed. In places the desert sands are even retreating.
Indeed, for most places at most times, the whole notion of desertification
increasingly looks like a myth.
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Consider the dusty desert margins of northern Nigeria around the ancient
caravan city of Kano, for example. Here, population density has soared to levels
similar to Belgium, and some 85 per cent of the land is now cultivated. Rainfall
is declining, the availability of chemical fertiliser has fallen by 80 per cent,
and only the richest farmers can afford high-yielding grain varieties or
irrigation. The poor make do with small scraps of sandy soils. Surely these
fields should be turning to desert dust as yields plummet, hunger spreads and
refugees head for the cities?
But that’s not what I saw when agricultural scientist BB Singh, who heads the
Kano office of the International Institute of Tropical Agriculture, drove me
through the area this summer. The dusty roadsides between the closely spaced
villages were busy with fruit and vegetable stalls and behind them the fields
were already green with bushes laden with the first cowpeas.
Under the burning sun, we visited Ado, a farmer who tends a 2-hectare plot on
the outskirts of Badume village, 50 kilometres northwest of Kano. Ado was
exultant. The previous year, he had harvested just two bags of cowpeas from his
plot. This year, he got seven bags for the same effort. He took me behind the
high mud walls of his compound to an inner sanctum where the reasons for his
success were bleating. He used to let his sheep roam free. Now he had half a
dozen of the animals tethered in his backyard, munching away at straw left over
from his fields and creating a large pile of manure for fertiliser. The last
mound of muck had been shifted just a few days before to fertilise the next
cowpea crop.
Sheep manure is transforming Ado’s life. “Now I can send my three children to
school,” he said. “The boys will become farmers, but I want my daughter to
become a doctor.” His neighbour Galadima was doing the same thing on his six
hectares. “Crops grow much better with manure,” he told me. “I don’t use
chemical fertiliser at all now that I have manure.” His two wives and 18
children came running out of the house and lined up for a family photo. They all
looked well fed.
Singh’s researchers are monitoring the effects of sheep manure in Badume, and
he confirms Ado’s interpretation of his success. But there’s another reason for
Ado’s progress, Singh adds—planting leguminous crops such as cowpeas,
which fix nitrogen from the air and deposit it in the soil. Frances Harris, a
soil scientist at Kingston University in Surrey, agrees that these two
strategies work. “The zone has supported intensive cultivation for many years
without suffering from land degradation,” she says. “The key is the integration
of crops and livestock, because it enhances nutrient cycling.” Legumes and
manure put back what the grain crops take out.
As a result, the Kano region is the most agriculturally productive part of
the country and farm yields of sorghum, millet, cowpeas and groundnuts are
growing rather than dwindling. All this in a region where many experts believe
only irrigation can produce worthwhile crop yields. Back in his small office in
a back street of Kano, Singh is adamantly optimistic. “Even less than 300
millimetres of rain is enough for good crops. We can double yields here easily
and improve the environment at the same time. And this is nothing unusual. We
can do it all over Africa.”
Harris makes another point—far from being a liability, the high local
population densities are actually essential to this form of intensified farming.
In a land where tractors are rare, people provide the labour to tend fields,
feed animals and spread manure. The old environmental shibboleth that rising
populations trigger soil abuse and desertification is being turned on its head
here. As is the idea that livestock are an environmental curse. Far from it,
livestock can be an ally of better farming.
All this would be a mere curiosity if the Kano story was a one-off. But
similar stories are emerging from all along the Sahara’s edge, from Niger and
Senegal, Burkina Faso and Kenya. David Niemeijer, an environmental geographer
from Wageningen University in the Netherlands, has spent the past seven years
studying the soils of eastern Burkina Faso. “I went there expecting to find
widespread land degradation, especially in the most densely populated areas,” he
says. After all, the area had seen a decline in rainfall and a tripling of
population over 40 years. “But there was no evidence of land degradation
connected to human activities. Nor was there any decline in farm productivity.
In fact yields of many crops had risen sharply.”
Rice and maize yields per hectare have tripled and sorghum, millet and
groundnuts doubled, says Niemeijer. And when he compared soil fertility today
with data collected during a French survey in the late 1960s, he found no
evidence of declining nutrients. He looked at changes in four different
nutrients—nitrogen, carbon, phosphorus and potassium—on five
different soil types. In 14 of the 20 comparisons, there was no significant
change from the 1960s data. Of the remaining six, four showed an improvement and
two a marginal decline in nitrogen. Phosphorus levels were actually higher in
cultivated soils than in fallow land. The results were the same for areas with
high and low population densities. Almost all the variation in farm yields, it
turned out, was down to rainfall.
So, what are farmers doing right? This is no high-tech breakthrough, nor a
result of Western aid programmes. Farming methods remain mostly traditional,
with few chemical inputs. Niemeijer’s colleague, social scientist Valentina
Mazuccato, asked the farmers their secret. “They do not need to invent new
management systems as land becomes more limited. All they do is apply some of
these soil and water conservation practices more intensively,” says Mazuccato.
They erect low walls of stone and earth to keep soil from washing off sloping
land in the occasional heavy downpours. They spend more time weeding and
thinning crops to improve yields without depleting soils. But above all, they
intensify their systems of cooperation, forming gangs to tend each others’ field
during busy times, and lending and borrowing land, livestock and farm equipment.
They swap seed varieties assiduously.
Whatever they are doing, it’s working. Burkina Faso produced 36 per cent more
food in 1998 than it did just eight years earlier, and per capita food
production is 20 per cent higher than in 1970. “I am optimistic,” says
Niemeijer. “Of course life remains hard. These farmers are still never sure if
they can feed their family, and they are not always in control of their
destinies. But things are not going down the drain.”
If farmers can maintain soils as they intensify production, can they also use
such techniques to rescue their land once it has begun a slide into
desertification? The evidence is that they can. Boubacar Yamba of the University
of Abdou Moumouni in Niamey, Niger, says that 20 years ago the Maradi district
in southern Niger was facing environmental crisis after repeated droughts.
Average rainfall was down 30 per cent, the population had doubled in 25 years,
soils were crumbling and the last forests were being cut down. Yet, though the
rains have never returned to former levels, the millet farmers have fought back,
diversifying into growing vegetables, trees and nuts and tending livestock.
Desertification has gone into reverse.
But perhaps the best researched example comes from Kenya. Sixty years ago,
British colonial scientists wrote off the eroding, treeless hillsides of the
drought-prone Machakos district of Kenya, east of Nairobi. Soil inspector Colin
Mather called those bare hills “an appalling example” of environmental
degradation. The local Akamba people, he said, “are rapidly drifting to a state
of hopeless and miserable poverty and their land to a parched desert of rocks,
stones and sand”. Similar reports came in the 1950s and again in the 1970s.
There have certainly been bad times, such as last year when the rains failed
altogether. But, even though Machakos’s population has risen a staggering
fivefold since the 1930s, most years these hills are greener, less eroded and
far more productive today than before. Farm output per hectare is ten times what
it was in the 1930s and five times what it was in the 1960s. There are, on
average, 34 trees per hectare, more than for a century or more. And with tens of
thousands of kilometres of terraces dug on steep hillsides, erosion rates are
probably also at an all-time low.
What are they doing right? According to Michael Mortimore, a British
geographer with long experience in Africa who has written a book on Machakos,
the Akamba responded to the environmental crisis by switching from herding
cattle to settled farming. This gave them the incentive—and their rising
population gave them the labour—to work the land properly, digging
terraces and collecting water in ponds for irrigation and weed control.
Every farmer seems to have his or her own story of innovation. On the road
out of Machakos town, for example, I dropped in on Jane Ngei, who used an ox
plough, spade and wheelbarrow to dig her own small dam to collect rainwater
running down the road past her farm. With bucket and perforated hose, she uses
the water to irrigate a couple of hectares of vegetables, maize and fruit trees
that she grows beside her fields. The Akamba farmers are reaping the rewards of
improvements like these, selling vegetables and milk to Nairobi, mangoes and
oranges to the Middle East, green beans to Britain and avocados to France.
Machakos district, recently renamed Makueni, is just a couple of hours drive
from Nairobi, home of the UN Environment Programme, which still maps much of the
district as on the verge of desertification. Yet, strangely, it has never sent
anyone to research the reality. UNEP’s Timo Maukonen says he believes the main
reason for the Machakos success story is the proximity of a large market,
Nairobi, for the farmers’ produce. Tom Slaymaker of Britain’s Overseas
Development Institute agrees. He stands by his claim in a recent study that
“there are few examples of reversal of natural resource degradation and no
evidence of a wider trend of environmental recovery.” He insists that
“successful cases seem to be rather isolated.”
But other experts are taking a more cautious line and question the value of
sweeping claims of environmental decline made by UNEP and other UN agencies.
Camilla Toulmin, head of the drylands programme of the International Institute
for Environment and Development in London and a leading drafter of the
Desertification Convention, admits that “evidence for soil fertility decline
stems from a few highly influential studies of land degradation in Africa, which
have been quoted over and over again, in the process often losing much of the
qualification surrounding the original study.” Much of it, she says, doesn’t
stand up to detailed investigation on the ground. “Detailed field-level studies
demonstrate that the soil fertility problem is far more complex and
徱.”
One problem has been that researchers tend to visit such areas so rarely that
they have little history to back up their guesses about environmental processes.
Land that appears “degraded”—that is, highly eroded—may have been
that way long before the arrival of farming or grazing. “Every piece of degraded
land has been seen as evidence of destructive human activity,” says Niemeijer.
“But when we asked farmers about areas of degraded land near their villages,
they generally said it had been there a long time and was a natural feature. And
in some cases they were starting to reclaim these areas for farming.”
Deserts did advance in Africa during the droughts of the 1970s and 1980s. The
conventional view at the time was that farmers, at least as much as drought,
were to blame, and that the processes were irreversible. But even when, in the
early 1990s, satellite images began to show the Sahara retreating during years
of higher rainfall, the image of desertification caused by human activity stuck.
It became what Mortimore calls an “institutional fact”, too important for
careers and reputations to be lightly dropped. And it is only now that detailed
evidence of what has happened to soils and farm productivity in these supposedly
doomed regions is finally emerging. The myth of traditional African farmers as
both environmental villains and victims is finally being exposed.
The truth is not that farmers never destroy soils, nor that deserts never
advance, but that there is nothing inevitable about the process—it may be
the exception rather than the rule. And even when soils have been in decline, as
in Machakos, farmers have shown themselves quite capable of turning the tide.
Moreover, it seems that even the rapid growth of population in many African
countries can be a spur to change, rather than a curse. As Singh puts it: “There
is no reason why Africa cannot feed itself.”