Fertile soil – thanks to participatory research


Florian Blumber, Biovision editor

Ten years ago, the fields of Patrick Maive and Joyce Wangari hardly yielded anything. That all changed when they set out to make their soil fertile again, with the help of Kenyan researchers.
Gemeinsam begutachten die Bäuerin Joyce Wangari und der icipe-Forscher Felix Matheri die Pflanzen auf ihrem Feld.
Together it works! Farmer Joyce Wangari and icipe researcher Felix Matheri in conversation. (Picture: J. Bastmeijer)

Joyce Wangari stands in the middle of her cabbage field in Kianjugu, Kenya, and points around with a sweeping arm movement. “These are the fruits of an organic farmer’s labour!” she says with a beaming smile.

Joyce, a mother of three whose husband works away from home, cultivates the vegetable field covering about a third of a hectare next to her house. A good ten years ago, she decided to stop feeding her family pesticide-laden, unhealthy vegetables and to convert her field to organic farming.

After that, it just took patience. As Felix Matheri, researcher and doctoral student at the International Research Institute icipe in Nairobi, explains: “The first soil analysis we carried out was sobering: the soil in the fields was lifeless, dry and poor in nutrients. Joyce had to compensate with artificial fertiliser – otherwise she would hardly have harvested anything.”

Scientists and farmers research together

Since 2005, icipe has been part of the long-term research programme SysCom, a project supported by Biovision and several partner organisations, run by the Swiss Research Institute of Organic Agriculture FiBL. SysCom stands for “farming systems comparisons” – comparing organic farming with conventional methods. A special feature of this project is that the researchers work closely with farmers. This ensures that research is carried out in a practical manner and that farmers can benefit directly from the existing and newly acquired knowledge of the researchers – and vice versa.

Assisted by Felix Matheri, Joyce Wangari began to build up compost, optimise the use of manure and diversify her crops. Within five years, her soil had recovered. “The cabbages are smaller than before,” she says. “But they are healthy and taste better. My customers at the market appreciate that.”

Onions to combat cabbage pests

She was also able to solve the problem of pest infestation in collaboration with Felix Matheri and his colleagues at icipe. The fermented plant and herb extracts that she made according to a traditional recipe and applied to the cabbage plants worked as a natural fertiliser, but not against pests. Laboratory tests revealed why: fermentation took away the pest deterrent effect of the extract. So from then on, Joyce Wangari applied it directly – which meant that she had an effective biological pesticide at her disposal.

The method of mixed cultivation was also optimised thanks to intensive exchanges between the smallholder farmer and the scientists. Like other farmers in the area, Joyce Wangari knew that onions could help against cabbage pests, so she grew onion plants around her cabbage field. The researchers discovered in experiments that the cabbages are much better protected when the onions are grown in rows between them. Joyce Wangari continued to experiment in her field and fine-tuned the ideal way to position the onions – which was highly beneficial to the researchers as well. “When it comes to using onions as accompanying plants, Joyce is now more of an expert than we are!” says Felix Matheri appreciatively.

Edward Karnja trägt auf dem Portraitbild eine Brille und ein gestreiftes Hemd.
Three questions to Dr. Edward Karanja

Why is the soil of many farmers in Kenya in such poor condition?

Many farmers don’t know what their soil is like and what would help it. To counteract a decline in crop yields, they use more and more artificial fertiliser – the soil becomes acidic and the diversity of soil organisms decreases. This means that it continues to lose fertility as well as the ability to keep pests and diseases under control. To remedy this, they treat the soil with synthetic pesticides, which damages it even more.

Has the participatory research approach proved its worth?

Our experience has shown that the POR trials – participatory on-farm research – are indeed the best way to communicate scientific knowledge in a simple and concise way. Again and again, we researchers make false assumptions. On the other hand, when we work directly with farmers, we hit the mark. As a result, many more farmers are able to apply our results.

What do you wish for the future?

I would like to see more research on agroecology in Kenya, more POR and more support from the government and development partners. We need to change direction in our food policy and improve soil fertility – otherwise we are putting the future of our agriculture at risk.

Exuberant plant diversity – nutrient-rich soil

The researchers were also able to learn from family man Patrick Maive, who runs a farm in the Kangari region that is similar in size to Joyce Wangari’s. Just like the cabbage farmer from Kianjugu, he decided about ten years ago to drastically reduce the use of synthetic pesticides and fertilisers – due to health concerns but also for financial reasons: agrochemicals are expensive. Patrick Maive’s soil was also completely exhausted and hardly yielded anything without artificial fertiliser.

That has since changed. “The soil is loose everywhere now, and there are no more compact, hard spots. I can even smell my ground!” he says. The fact that Patrick Maive now has healthy soil again is thanks partly to tips from the icipe researchers – and partly to his own ideas and drive. When Felix Matheri and his colleagues advised him to make conventional compost and add it to his soil, he came up with the idea of working with worm compost. This has a high microbial content and can be used rapidly. Felix Matheri explains how he immediately took up Patrick Maive’s idea and recommended it to other farmers.

Avocados and Honey

Felix Matheri is enthusiastic about Patrick Maive’s farm in general. Previously he was only able to grow maize and beans: “We recommended that he should adopt greater crop diversity – but what he achieved as a result exceeded our wildest expectations!” In fact, the results have little in common with a conventional vegetable field: banana palms grow next to cassava plants, bean bushes alternate with maize plants, and tree-high sunflowers can be seen everywhere. And there are even 23 beehives hiding in the shade of avocado trees. This diversity of crops also brings diversity of food for the soil. And it increases resilience to crop failures, which are becoming more frequent due to climate change: if the bean harvest is bad, Patrick Maive can still harvest cassava.

“My favourite plant is the avocado,” he says. “It sells best at the market.” His honey is also hugely popular. With the income, the innovative farmer has been able to build an additional house and a new well on his farm. The better availability of water in turn helps him to withstand adverse weather conditions even more effectively. Patrick Maive is as motivated as ever: he is currently undergoing training at icipe in the organic maize cultivation method Push-Pull in order to perfect his organic cultivation and further increase his harvests.

“Be patient and wait and see: it’s worth it!”

He is keen to pass on what he has learned – his neighbour rapidly expressed interest. Joyce Wangari also says: “I tell my neighbours how well organic farming works and show them the methods I have learned. When they don’t believe me, I tell them to be patient and wait and see: it’s worth it.” The enthusiastic organic farmer hopes that the cooperation with the SysCom employees will continue for a long time. They are currently working with her on a joint solution to combat moth scale insects in beans. Unfortunately, as trials have shown, onions work very well as accompanying plants for cabbages, but not for beans. While chilli, coriander or tagetes produce good results with other plants, the farmers and the researchers are still looking for the optimal solution for beans.

Despite the many insights that SysCom has already brought, research into biological solutions in Kenya and other tropical countries is still in its infancy. Felix Matheri is convinced that there are many treasures yet to be unearthed: “We have only scratched the surface.”



“Organic is the right way to go”

Portrait of the smallholder Josephine Ithiru from Chuka, Kenya: She knows for herself that organic farming is the right way. After all, the long-term comparison of organic farming methods shows that in the long term organic methods are more financially successful for women farmers like Josephine.

Josephine Ithiru and her Toggenburger Goats

The seventy year old farmer Josephine Ithiru from Chuka (Kenya) participates in a scientific long-term study. Organic and conventional cultivation methods are being compared and Ithiru is testing different fertilisers. After the first test phase it has already become clear that organic cultivation is the better solution.