Strategies used to reduce the risk of desertification
Desertification is not inevitable and with careful management of water resources, the soil and vegetation via tree planting we can limit the spread of deserts. We have even managed to reverse the effects of desertification. Many of the techniques used have used appropriate technology, which is suited to the needs, skills, knowledge and wealth of local people in the environment which they live.
Tree Planting - Senegal
In the Senegal region of the Sahel (a 5,000km long belt of land that separates the Southern part of Africa from the Sahara) the Food and Agriculture Organisation (FAO) of the UN is trying to help in the fight against desertification. Less than 50 years ago land in this region of the Sahel was productive Savannah, but is now dry desert because of decades of climate change and over intensive farming, forestry and land degradation. This has led to vegetation disappearing.
A project focussing on Acacia or gum trees is trying to help. The FAO and forestry service have provided nursery’s to grow seeds and seedlings. The locals were also taught how to sow and plant the Acacia trees, and how to extract and market the gum they produce.
They were also given a tractor and digger tool specially adapted to dryland conditions. It cuts half moon shaped holes which collect rainwater ensuring that the young plant roots will have enough water to survive the long dry season. This also massively reduces the amount of labour needed.
An Acacia nursery
Planting the trees reverses desertification by preventing soil erosion and providing nutrients for other plants and crops to grow. The tree is a native tree, it puts nutrients back into the soil, provides shelter for crops under its branches and provides fodder for livestock.
The knock on effects have been good for the whole community.
Tractor ploughing crescents
The Great Green Wall
The Great Green wall is a planned project to plant trees across Africa along the southern edge of the Sahara Desert to prevent the desert spreading south. It has been developed by the African Union to reduce the negative effects of desertification and land degradation on people, the environment and the economies of the countries affected.
Stone lines – Water and soil management
Desertification leads to outmigration in countries such as Burkina Faso in the Sahel. This idea was to lay stones along the contours of the land in long lines which traps the rainwater that falls. A contour stone line 25 to 30cm high with other stones behind is constructed. These stones slow down run off water and allow it time to infiltrate the ground and rich sediments to be trapped in the field. This results in less erosion and more water for the crops.
Farmers were trained in laying out contours using a simple water tube level. They marked out the contours and dug out a foundation trench. Large stones are then placed into this trench followed by smaller ones. Grasses can also be planted along the barrier. The villagers work together and it is a collective effort. The technique has spread from Burkina Faso to Mali and Niger. It is a technology that is low cost and requires skills that can be quickly learned.
Planting pits are also used to hold more water around the plant and homemade compost is used to provide a fertility boost for the soil. Barren land has been restored and vegetation re-established so the scheme has been a big success and sustained.