The 1960s' Green Revolution demonstrated how technological innovations can transform agriculture. High-yielding crop strains, irrigation, fertilisers and pesticides were brought into developing countries, including India and the Philippines, increasing yields by more than 250 per cent and pulling over a billion people back from the brink of starvation.

Despite its impact, criticisms of this top-down model of technology transfer included its failure to reach poorer smallholder farmers who could not always take advantage of the technologies. And today, many parts of the developing world, particularly in Africa, still have low adoption rates for agricultural technology.With smallholder farmers producing more than 70 per cent of the world's food, according to Patrick Mulvany, chair of the UK Food Group, an NGO network, calls have been made for more-sustainable, flexible and inclusive innovation systems to meet their needs.

And now, there are examples of farmer-led innovations that bring smallholders and researchers together to increase yields.

Journey from lab to farms

The International Centre of Insect Physiology and Ecology (ICIPE), based in Kenya, was established in 1970 to tackle the special problems facing developing countries in the tropics. One of these was the stemborer moth, whose larvae burrow into maize stems, causing up to 80 per cent losses. Many intervention technologies are unsuitable for smallholder farmers. For example, although pesticides could help, they are often unaffordable and could cause ecological damage.

There are other challenges regarding the uptake of pest-resistant crops. Zeyaur Khan, a principal scientist with ICIPE, explains: "Even if you breed them, the farmers don't like the taste. They generally like to eat what they have selected for a long time and gotten used to."

In 1993, Khan was tasked with developing pest control that better suited farmers' needs and would be more widely adopted. Based on the principles of natural pest control, Khan developed what is known as the 'push-pull' approach.

Push-pull involves growing plants among the crops that emit chemicals that repel the moth. These 'push' the stemborer moths out, while other types of plants sown around the field borders attract ('pull') them away.After researching nearly 600 species of grasses, Khan discovered varieties that attracted the egg-laying moths, but which did not allow their larvae to develop - what seemed like the perfect 'pull' mechanism.

But first he had to convince the farmers to plant the grasses.

"Asking the farmers to plant a grass on their farm was something I was quite hesitant of," Khan explains. "I thought I would look foolish because they know the grasses better than us. And also, what would happen if we told them to plant them, and they became a serious weed on their fields?"

Khan's fears appeared to be justified - the farmers refused to plant grasses unless he and his colleagues demonstrated an additional use for them, for example as animal fodder.

"The knowledge and innovation capacity of farmers is a big untapped resource."

(Camilla Toulmin, IIED)

So Khan's team invited the farmers back to their field station to select a better grass. Together they carried out further experiments, eventually finding a variety that made perfect fodder, while also having 'pull' properties for stemborers. And once 'pull' was in place, stemborer damage dropped to under ten per cent.

Unexpected hurdles- added benefits

Meanwhile in Nyanza, western Kenya, maize farmers faced an even bigger problem - Striga weed was wiping out fields. As a result, the district's agricultural officers refused to introduce Khan's stemborer-control technology unless it also dealt with Striga. This was a key influence in the search for an ideal 'push' mechanism, Khan says.His team found a type of legume, Desmodium, which not only repelled stemborers but also prevented Striga growth. And as a bonus, Desmodium worked as a natural fertiliser by fixing nitrogen in the soil and was a high-protein fodder.

Because of this farmer-led innovation, more than 68,000 farmers in East Africa have adopted the 'push-pull' technology and there are plans to introduce it to South American coffee and cotton farms.

"What you need is championship and ownership," explains Khan. "If the farmers don't think of this technology as theirs, they will not think about using it.

Our farmers have given a lot of good suggestions: how to modify it and adapt it to their own circumstances. They feel very proud about it. And so that feeling of ownership is very important."

Including indigenous knowledge in the innovation process not only ensures the technology is appropriate, raising adoption rates, but also keeps it flexible, because the farmers' advice adds a local context, letting the technology evolve and reinvent itself for every new situation. Khan is clear that the technology is so adaptable because it was developed in Africa, not imported.

This approach is well-suited to the millions of smallholder farmers facing a spectrum of challenges all over the continent, he says.

Farmer field schools
"The knowledge and innovation capacity of farmers is a big untapped resource," says Camilla Toulmin, an economist and director of the International Institute for Environment and Development. "Surviving in a tough, uncertain environment gives farmers many insights they've had to develop from daily practice."

Some have gone further in attempting to set up broader systems to foster and disseminate knowledge of appropriate innovations within agricultural communities.

First implemented in 1990 in Indonesia, farmer field schools responded to the challenges presented by the top-down model driving much agricultural technology dissemination in the developing world.

William Settle, a senior technical officer at the UN's Food and Agriculture Organization, was a researcher in Indonesia at the time. He says: "The idea was that certain types of technological decision-making could not successfully be prescribed through a simple 'laundry list' of activities that farmers were 'supposed' to do. Farmers were, in most cases, going to do what their fathers had done or their neighbours were doing."

Based on the principles of discovery-based learning, or 'learning-by-doing', field schools typically consist of 25 farmers meeting once a week. Each school has one training field divided into two parts: one follows a 'usual' treatment regime for the area, while the other trials treatments considered to be 'best practice'.

Participants manage the fields, make observations and discuss the results. And through involvement in these field experiments from start to finish, the farmers learn about various innovations that could be suitable for their areas.

"The first meeting involves farmers sketching out their agricultural system and discussing what their priorities and main bottlenecks are," Settle says. "Then they'll try to tailor the field school to attend to those particular needs."After running in 12 countries in South-East Asia and training millions of farmers in Indonesia and Vietnam, the first field school programme in West Africa was introduced in Ghana in 1996.

"It reinvents itself in every new context and the context in West Africa is different: instead of pests and pesticides, the biggest issues are to do with soil fertility management, quality seeds, water and natural resource management," says Settle.

By connecting communities with mutual interests and encouraging idea-sharing, the field schools' framework builds knowledge networks that harvest innovations for use elsewhere. And innovations are only adopted when trialled in a local context and found to work by the farmers.

Recently in Mali, field schools on naturally occurring pesticides helped 6,000 farmers use 47,000 litres less pesticides (a 90 per cent reduction), saving them nearly US$500,000 in total. And now field schools are turning to innovations for diversifying crops and livestock, making farms become more resilient to market price fluctuations.

The end of technology transfer?

But while these horizontal innovation systems are a promising alternative to the top-down model, fostering the developing world's capacity to develop home-grown innovations remains difficult.

"The main challenge is the investment in science," explains Khan. "Most labs are not very well equipped in Africa. And sometimes there is a 'brain drain'. People leave to work in the developed world and those who are left are pulled into administration."

Yet research investments made elsewhere could also have an impact in developing nations.

"Hundreds of international companies continue to provide a steady flow of new agricultural technologies into the developing world," says Gert-Jan Stads, one of the authors of a report published in August by the International Food Policy Research Institute, which argues that conventional technology transfer is still essential.

"So investing in research elsewhere in the world may be just as critical to technical progress in Africa as enhancing the capacity to develop home-grown technologies."

Drawing on innovation expertise from the developed world can make the most of knowledge already learnt by established and well-resourced research groups.

But harnessing indigenous expertise within appropriate innovation frameworks will ensure farmers have real choices and control over the technologies they adopt, and that local innovations are disseminated as widely as imported technologies.

This article is part of the Spotlight on Producing food sustainably.