Conserving and rehabilitating Africa's lands

Africa's lands - croplands, savannah, bush and forests - are in danger. Poor land management is resulting in rapid land degradation: massive soil losses, falling yield potentials, deforestation, the disruption of water resources, and the destruction of natural pasture. The same is true in many parts of the Caribbean and Pacific. Land mismanagement usually results from removing too much, returning too little and cultivating, grazing or cutting too frequently. Land degradation is proceeding so fast that few countries can hope to achieve a sustainable agriculture in the foreseeable future; yet land degradation can be prevented and even reversed. Traditional systems of land use rarely led to rapid deterioration except where large populations were concentrated. Even there, farmers often developed sophisticated and effective conservation measures to overcome the risk of degradation, and to maintain or even raise crop and livestock yields. One such example is southern Ethiopia where the Konso people live in a steep erodible area subject to unreliable rain-fall. Over the years, the Konso have terraced most of their land and developed a complex system of agroforestry and water harvesting. Compost and manure are spread in the fields to maintain fertility, while cattle are stall-fed. The cabbage tree (Moringa stenopetala), from which young green leaves are collected as a vegetable, is planted together with fruit trees in the cropped fields. Planting density is increased on the wetter sites. On steeper slopes, terrace walls are made from double layers of rock, and the space between them is filled with soil and planted with leguminous crops. A variety of annual and perennial crops is sown in staggered or relay-cropping sequences; usually sorghum, finger millet or maize is the main crop, mixed with beans, peas, lentils, fruit trees, medicinal plants, spices, oil-seeds, firewood and timber trees, root crops and cash crops such as cotton and coffee. Another country where effective conservation measures are practiced is Rwanda, one of the most densely populated countries in Africa. Although most d the population remains dependent on agriculture, some families now have only 0.2-0.5ha of land to farm. Being a mountainous country with tropical rainfall, there is serious risk of erosion. Under these conditions Rwandan farmers have devised ways of maintaining and even increasing yields while protecting the soil from erosion. Land management is based on stall feeding a cow or several sheep to produce manure for composting. Fodder is grown on the banks of the terraces and is fed, together with vegetable waste, to the animals. The compost is spread on the terraces to in crease the organic content of the soil, thereby increasing its permeability, improving its water storage capacity, raising its fertility and hence increasing crop yields and reducing erosion. Rainwater running off roofs is trapped and stored underground for human and livestock use. Land degradation has many causes and there is no universal solution. But the problems of land degradation can be overcome if each country develops its own conservation strategies, policies and programmes tailored to its own peculiar circumstances.

Africa's lands - croplands, savannah, bush and forests - are in danger. Poor land management is resulting in rapid land degradation: massive soil losses, falling yield potentials, deforestation, the disruption of water resources, and the...