Vol. 169, Issue 2276, Page 16
February 3, 2001
AN ORDINARY MIRACLE
Bigger harvests, without pesticides or genetically modified crops? Farmers can make it happen by letting weeds do the work
By Fred Pearce
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. "It's better than pesticides, and a lot cheaper," 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. "And it has raised farm yields round here by 60 to 70 per cent."
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 "sustainable agriculture" 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 January this year the world's 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--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 "cheap, use locally available technology and often improve the environment. Above all they most help the people who need help the most-- poor farmers and their families, who make up the majority of the world's hungry people."
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's 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. "In 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." The difference, he says, comes from "the reduction of losses due to weeds, insects and diseases and a more efficient use of the available resources of water, light and nutrients". 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. "I don't see GMs making an impact on food production in Africa within the next 10 or 15 years," says Herren. "What Africa most needs is investment in 'soft' biotechnologies such as alternative natural pesticides." ...
Pretty says: "Things 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." 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.
© Copyright New Scientist, RBI Ltd 2000