ACROSS east Africa, thousands of farmers are planting weeds in their maize
fields. Bizarre as it sounds their technique is actually raising yields by
giving the insect pests something else to chew on besides maize. 鈥淚t鈥檚 better
than pesticides, and a lot cheaper,鈥� said Ziadin Khan, whose idea it is, as he
showed me round his demonstrations plots at the Mbita Point research station on
the shores of Lake Victoria in Kenya. 鈥淎nd it has raised farm yields round here
by 60 to 70 per cent.鈥�
His novel method of fighting pests is one of a host of low-tech innovations
boosting production by 100 per cent or more on millions of poor Third World
farms in the past decade. This 鈥渟ustainable agriculture鈥� just happens to be the
biggest movement in Third World farming today, dwarfing the tentative forays in
genetic manipulation. It seems peasant farmers have a long way to go before they
exhaust the possibilities of traditional agriculture and have to place their
futures in the hands of genetic engineers.
In east Africa, maize fields face two major pests, and Khan has a solution to
both. The first is an insect called the stem borer. True to its name, its larvae
eat their way through a third of the region鈥檚 maize most years. But Khan
discovered that the borer is even fonder of a local weed, napier grass. By
planting napier grass in their fields, farmers can lure the stem borers away
from the maize鈥攁nd into a honey-trap. For the grass produces a sticky
substance that traps and kills stem borer larvae.
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The second major pest is Striga, a parasitic plant that wrecks
$10 billion worth of maize crops every year, threatening the livelihoods
of 100 million Africans. Weeding Striga is one of the most
time-consuming activities for millions of African women farmers, says Khan. But he
has an antidote: another weed, called Desmodium. 鈥淚t seems to release
some sort of chemical that Striga doesn鈥檛 like. At any rate, where
farmers plant Desmodium between rows of maize, Striga won鈥檛
驳谤辞飞.鈥�
Khan鈥檚 cheap fixes for Striga and stem borer are spreading like
wildfire through the fields of east Africa. Trials on more than two thousand
farms are finished. 鈥淚t鈥檚 out of our hands now,鈥� says Khan鈥檚 boss, Hans Herren,
who is the director of the International Centre for Insect Physiology and
Ecology in Nairobi. 鈥淭he ideas are being taken up by farmers in countries such
as Ethiopia where we have never worked.鈥� Khan, meanwhile, is going back to the
wastelands of Kenya looking for more grasses to kill common pests.
His miracle is one of dozens of different strategies transforming the lives
of millions of poor farmers on small farms across the planet. They replace
pesticides with natural predators, and fertilisers with animal dung, crop wastes
and plants that fix nitrogen from the air. They choose artful combinations of
crops that maximise nature鈥檚 bounty.
In January this year the world鈥檚 largest study into sustainable agriculture
was published. Jules Pretty of the University of Essex analysed more than 200
projects in 52 countries. He found that more than four million farms were
involved, covering an area the size of Italy鈥�3 per cent of fields in the
Third World. And, most remarkably, average increases in crop yields were 73 per
cent.
Sustainable agriculture, Pretty concludes, has most to offer to small farms
that cannot afford chemical solutions to their problems. Its methods are 鈥渃heap,
use locally available technology and often improve the environment. Above all
they most help the people who need help the most鈥攑oor farmers and their
families, who make up the majority of the world鈥檚 hungry people.鈥�
And, hardly surprisingly, many of the successful techniques are now being
adopted by agribusiness. Raising fish in rice paddies, for instance, began in
Bangladesh but is now developing into a global industry. Khan鈥檚 alternative
pesticides are likewise finding a potential market on large farms anxious to cut
the cost of conventional pesticides.
The success of sustainable agriculture is dispelling the myth that modern
techno-farming is the most productive method, says Miguel Altieri of the
University of California, Berkeley. 鈥淚n Mexico, it takes 1.73 hectares of land
planted with maize to produce as much food as one hectare planted with a mixture
of maize, squash and beans.鈥� The difference, he says, comes from 鈥渢he reduction
of losses due to weeds, insects and diseases and a more efficient use of the
available resources of water, light and nutrients鈥�. Monocultures breed pests and
waste resources, he says.
And some experts think GM crops will pale by comparison with sustainable
agriculture, at least for the time being. 鈥淚 don鈥檛 see GMs making an impact on
food production in Africa within the next 10 or 15 years,鈥� says Herren. 鈥淲hat
Africa most needs is investment in 鈥榮oft鈥� biotechnologies such as alternative
natural pesticides.鈥�
Researchers from the Association Tefy Saina, a Madagascan group working for
local farmers, were looking for ways to boost rice yields on small farms. They
decided to make the best use of existing strains rather than track down a new
breed of super-rice.
Through trial and error, Henri de Laulaine, a local Catholic priest, had
stumbled on a system that raises typical rice yields from 3 to 12 tonnes per
hectare. His trick is to transplant seedlings earlier and in small numbers so
that more survive; to keep paddies unflooded for much of the growing period; and
to help the plants grow using compost rather than chemical fertilisers.
杏吧原创s have been sceptical about the ability of poor farmers to achieve
such spectacular results, says the association鈥檚 Sebastien Rafaralahy.
Nonetheless, de Laulaine鈥檚 idea has spread like wildfire: 20,000 have adopted
the idea in Madagascar alone.
Following a collaboration with Cornell University in Ithaca, New York, the
system has been transplanted to the Asian heartland of rice cultivation. In
tests, China, Indonesia and Cambodia all managed to raise their rice yields.
Few countries have switched wholesale to sustainable agriculture. But Cuba
has. The collapse of the Soviet Union in 1990 cut off cheap supplies of grain,
tractors and agrochemicals. Pesticide use halved overnight, as did the calorie
intake of its citizens. The cash-strapped country was forced to embrace
low-input farming or starve.
Today, says Fernando Funes of the country鈥檚 Pasture and Fodder Research
Institute, teams of oxen replace the tractors, and farmers have adopted organic
methods, mixing maize with beans and cassava and doubling yields in the process,
helping average calorie intake per person rise back to pre-1990 levels.
Worldwide, one of the most widely adopted sustainable techniques has been to
throw away the plough, the ultimate symbol of the farmer. Ploughing aerates the
soil, helping rot weeds and crop residues. But it can also damage soil fertility
and increase erosion. Now millions of Latin American farmers have decided it
isn鈥檛 worth the effort. A third of Argentina鈥檚 farms no longer use the plough.
Instead, they fight weeds by planting winter crops such as black oats, or by
spraying a biodegradable herbicide such as glyphosate. 鈥淭he farmers saw results
in a short time鈥攔educed costs, richer soils, higher grain yields and
increased income,鈥� says Lauro Bassi of EPAGRI, the agricultural research
institute in Santa Catarina state, southern Brazil, which has been promoting the
idea.
Zero-tillage also benefits the planet in general. Unploughed soils hang on to
carbon that would otherwise escape into the air as carbon dioxide when organic
matter rots. A one-hectare field left unploughed can absorb up to a tonne of
carbon every year, says Pretty, making soils a vital element in preventing
global warming.
Sustainable agriculture is no magic bullet for feeding the world. It is an
approach rather than a blueprint. Small farms with low yields stand to benefit
the most and agribusiness the least. But it does offer an alternative for the
millions of small farms that have plenty of hands to work the land but not the
skills or financial resources to adopt conventional mechanised farming.
Pretty says: 鈥淭hings are happening that are very exciting. If it catches on
we can make substantial inroads in reducing the 800 million people who still go
to bed hungry every night.鈥� Perhaps the most dramatic evidence of its success so
far, he adds, is that little of the extra produce ever finds its way to distant
supermarkets while the farmers starve. Most of it is eaten by the people who
grow it.