Hedging your bets
Dead wood is usually seen as good for little more than fuel for fires but, throughout the Sahelian region of West Africa, dead wood is much more than that. It is also a precious resource that farmers use to protect their income-generating gardens during the long and difficult dry season. They may walk many miles and use weeks of their precious time and energy to find the material they need to build the fences used to keep livestock from eating the fruits and vegetables grown for sale at local markets. But much of this 'dead wood' comes from living trees that the Sahel can ill afford to lose. Some farmers also use millet and sorghum stalks to construct these fences, but this deprives the fields of enriching organic matter. So the pressure is on to find an alternative solution for fencing.
Coming to life
In a small village in Burkina Faso the fences are coming alive. In a country where deforestation and soil erosion are having a disastrous impact on the environment, live fences, are a simple but effective agroforestry practice. Not only do they protect the fragile countryside but they also bring enormous benefits to farmers by improving farm productivity and income. With the help of the International Centre for Research in Agroforestry (ICRAF) farmers are planting a variety of tree species to form thick, thorny, live fences as a protective, permanent barrier around their gardens. With their produce protected from roaming livestock, farmers are able to sell the surplus fruit and vegetables they grow at local and large urban markets, bringing in valuable income during the months of drought, which can number up to nine months in the semi-arid lowlands of West Africa.
Additional value
Konki Ipala is the small village, 37 km west of Ouagadougou where
the first on-farm trials have taken place to test the agroforestry
techniques 
involved
in live fences. The collaborative project between IRBET (Institut de
Recherche en Biologie et Ecologie Tropicale) and ICRAF has linked up
with the farmers in the village to ensure that the species used in the
live fences, and the practices used to establish the plants, meet
farmers' needs in a variety of ways. The species selected for use
in the trials were: Acacia senegal, Ziziphus mauritiana, Acacia
nilotica and Bauhina rufescens. All the species, with the
exception of Bauhina, have thorns to prevent livestock from
pushing through fences. They also all provide valuable, additional
products that farmers can use: Acacia senegal provides Gum
Arabic and fodder; Acacia nilotica provides medicinal products
and is also used in tanning; Ziziphus mauritiana provides
fruits which can be sold at the market and the leaves, as with Bauhina
rufescens, are used for animal fodder.
Elias Ayuk, an agro-economist with ICRAF who is currently involved in the live fence trials with the farmers of Konki Ipala, says the reason for having a mixture of trees is that "they provide a service function - protection - and a productive function - providing additional products for use by farmers." Another advantage, he continues, is that, "In the case of any parasitic attack of one particular species, the other species can still provide protection." A final bonus is that the variety of species increases biodiversity in a country where deforestation is common and species are in danger of disappearing.
Clever construction
To form an effective barrier against livestock the four species are planted in a continuous, but staggered double row. 50 cm is left between the plants in the same row and 25 cm between the rows of plants. The outside row of plants consists entirely of Acacia nilotica and other species: Acacia senegal, Ziziphus mauritiana and Bauhina rufescens are planted in equal numbers to form the inner line of trees.
To give the trees the best possible chance of becoming established, a trench is dug around the garden to a depth of about half a metre. The plant roots are then placed in the trench and it is simply refilled. This allows the roots to develop and for the soil around the trees to absorb water more easily. After only two seasons, the fences are solid and thick enough to keep out wandering livestock. Farmers who have found that it is too expensive to buy the seedlings have tried direct sowing of seeds into the trenches. The fence takes a little longer to become established but the overall costs are dramatically reduced.
Dead or alive?
Despite the attractions of live fences it cannot be denied that much work is involved in establishing them: the trenches take several days to dig and the seedlings have to be weeded. The hedge may also have to be pruned to cause branches to grow at the base of the plants so that the barrier is effective from ground-level.
But farmers who have successfully established their live fences have more time to spend on their market gardens, saving the 8-10 days at the beginning of the dry season - days which were traditionally used to find material and repair dead fences. And productivity has increased to provide farmers in Konki Ipala with an extra US $60-100 per season. In a country where average annual income is less than US $300, that is a lot of money. The success and appeal of the technology can also be demonstrated by its spread: in this small village alone another 15 farmers in the past year have planted live fences by direct seeding. Live fences are already being used in Mali. Indeed, this simple technology has the potential of branching out across much of West Africa and beyond.
