News
Farmers and soils in Africa can benefit from legumes
Published: 29 October 2019
More legumes in east Africa can improve food security and soil fertility, provide feed and fuel, and also reduce soil erosion. In his thesis from SLU, Tarirai Muoni investigated the potential of legumes and what the farmers think of them. Many farms are small and it is risky for a farmer to experiment. But if they see that growing legumes works, they are prepared to change their farming system.
Most farms in east Africa are very small and have less than 2 ha of land. Many farmers practice integrated crop and livestock farming. The most common crops include maize (Zea mays), cassava (Manihot esculenta), tobacco (Nicotiana tabacum), sorghum (Sorghum bicolor) and common bean (Phaseolus vulgaris). The animals you see are often cattle, sheep, goats, and poultry.
The population is growing, that means an increasing demand of food and fuel. The rainfall patterns are affected by climate change and are now often characterized by long mid-season dry spells which reduce crop yields. The soils are often poor in nutrients and the farmers can seldom afford manure. Legumes cannot solve all these problems, but integrating more legumes into the crop-livestock farming systems would provide many benefits.
"I see legumes as a part of the future. They fulfil many purposes - more food, feed and fuel. Using legumes can improve soil fertility and reduce erosion", says Tarirai Muoni.
Interviewed farmers
He has interviewed farmers in Kenya and Democratic Republic of the Congo to find out how they perceive legumes. In general, the interviews showed that farmers appreciated legumes mostly because they provide food and income and not so much because they can provide animal feed, fuel, increase soil fertility and prevent erosion. The farmers do not grow many different legumes, mostly common beans.
But there is a great deal of interest from the farmers.
- When we conducted the experiment in Kenya, many people came and asked questions. The farms are small and farmers are reluctant to test new things. If it goes wrong it could mean that the family faces food shortage before they reach the next season harvest. So it's good if you have crops that look good and can show that it works, says Tarirai Muoni.
Legumes conttribute different things
In the experiment, Tarirai found that mixing legume crops including herbaceous and woody species in cropping systems increases soil cover, which reduces runoff and soil erosion. Mucuna as sole crop and Calliandra hedgerows in maize-common bean intercrop produced both higher soil cover and more above ground biomass compared to farmer practice (maize-common bean intercrop), which resulted in higher infiltration rates and numbers of earthworms.
It is clear that different legumes contribute different things to cropping systems. For example, lupin and pigeon pea are good for supplying nitrogen to the soil and woody species can contribute to animal feed.
Tarirai's research has improved a tool called LegumeChoice. It gives the farmer a list of legumes suitable for the growing conditions and explains, what different legumes can add to the farming system. With the help of LegumeChoice, farmers can make the right decisions for their particular farm.
Contact
Tarirai Muoni tarirai.muoni@gmail.com
Ingrid Öborn (supervisor) ingrid.oborn@slu.se