Trees are also used as live fences. Live fences may serve several functions including protection of gardens against animals and wind erosion (windbreaks), and for land delimitation.

About 80 % of gardens are protected with dead wood (Yossi 2006), but this type of fence often needs repair. The live fence is on the other hand permanent. A live fence must be protected by a dead fence during the first years. Farmers choose trees to use for the live fence based on their protective capacity, the pace of establishment, the manpower required for maintenance, the value of the products, and potential nutritional or medicinal qualities (Levasseur 2004, Yossi 2006).

The trees are planted in a hole (Yossi 2006) in which 0.5 kg of manure or compost is added at the time of plantation or sowing. The space between trees on the rows may be about 0.5m. The live fence may be constituted of one or two rows. In case the fence is constituted of two rows of trees, the latter must be planted in a quincunx in order to increase the fence’s effectiveness. However, a two-line fence has drawbacks in the sense that it is difficult to weed between the lines and the risk of bush fires increases (Yossi 2006). Planting is done when the rainy season has really set in. An application of mineral fertilizer can further increase plant growth. After a year, it is recommended to add manure. ICRAF has shown that direct sowing with A. nilotica is an easy way to establish a live fence.

Maintenance after installation is very important. It is recommended to undertake two weedings during the rainy season. Two years after the installation of the fence, it is recommended to cut it back to a height of 0.5 m in order to have a thicker fence.

Local trees which are most often used are the Acacia nilotica, Acacia senegal, Bauhinia rufescens, Ziziphus mauritania, Zizyphus mucronata (Yossi 2006) and Zizyphus spina-christi. The Acacia nilotica is often used in live fences. Tannin, which is used for the production of high value leather, is produced from green pods from Acacia nilotica. The young Acacia nilotica pod is good fodder as well. The Acacia senegal provides gum while the Zizyphus spina-christi is used for various ends. 

The Ziziphus rotundifolia is also a species originating from which could be used as a live fence (source D. Paternak). This species establishes more rapidly than local species such as Acacia nilotica. It produces fruits that are highly appreciated by humans. This tree must be cut when young so that it may form a denser live fence.

Henna (photo) is another alternative as a live fence, but goats graze this tree if there is no other plant. Henna is an important species in the Sahel. It is mostly used by women for various purposes. An Indian variety has a twofold yield and a higher resistance to drought than local varieties.

More information on live fences:
http://www.worldagroforestry.org/downloads/Publications/PDFs/OP14457.PDF

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