Africa Environment Outlook

LAND QUALITY AND PRODUCTIVITY IN CENTRAL AFRICA

Land degradation, defined as the deterioration in the quality and productive capacity of land (Benneh, Agyepong and Allotey 1990), has been identified as one of the major environmental challenges facing the central Africa sub-region. The main contributors to land degradation in this sub-region are erosion and soil compacting, as a result of extensive removal of vegetation, and exposure of the soils to heavy rainfall, increased evaporation and wind action. The main reasons for vegetation removal are commercial logging and tree cutting to provide domestic fuel, as well as clearance of forests for commercial or subsistence cultivation.

The rate of forest loss in central Africa is a cause for concern in terms of its impacts on biodiversity, atmospheric change and hydrological cycles, in addition to the concerns regarding soil erosion (UNU 1998). Chemical degradation also occurs, because of: intensive cultivation of marginal areas without sufficient fallowing; use of chemical rather than organic fertilizers; and salinization, through inundation with saltwater or irrigation with poor quality water. For example, the Congo basin has lost more than 1 million ha of original forest cover, contributing to soil erosion and the sedimentation of waterbodies (WRI 2001). The Lake Chad basin has also suffered severe vegetation loss, and potential for soil loss and desertification is high (WRI 2001).

Goat herd overgrazing fragile pasture, Chad

Vincent Dedet/Still Pictures

Declining productivity and soil structure in the Sahelian zones of Chad and Cameroon are exacerbated by unpredictable rainfall and drought, resulting in extreme degradation and desertification. Chad is currently experiencing the greatest vulnerability to desertification, with 58 per cent of the area already classified as desert, and 30 per cent classified as highly or extremely vulnerable (Reich and others 2001). There is a large area in Democratic Republic of Congo (64 per cent), which is classified as hyper-arid, and sands of the Kalahari desert have encroached on the savanna vegetation (Reich and others 2001). Central African Republic and northern Cameroon have also been experiencing desertification since the severe drought of 1972-73 (Njinyam 1998).

In the coming decades, the threat of desertification will increase, as a result of climatic changes, such as: increased evaporation; reduced rainfall and run-off; and increased frequency and severity of drought (IPCC 2001). In addition, civil unrest or conflict can result in vast movements of refugees, many of whom are settled in marginal or fragile areas. Such social and environmental pressures were clearly demonstrated in 1997, when Central African Republic (having to cope with internal disputes) received more than 50 000 refugees from Sudan, Chad, Democratic Republic of Congo, Congo Brazzaville and Rwanda. The arrival of these displaced persons put a visible strain on the already stressed food security situation (Njinyam 1998).

The consequences of land degradation, and of soil erosion and compaction, are manifest as a result of the declining ability to support natural or domesticated plant and animal production. Ultimately, this translates to reduced nutritional status of the population and to reduced export revenues. In addition, communities which are dependent on wild produce-such as fruits, nuts, animals and mushrooms, and wood for fuel-have to search further and further afield to meet their needs, and may experience food shortages or even famine during drought years. Extreme reductions in productivity may result in people abandoning their farms and migrating to urban centres, in search of improved security.

Improving land quality and productivity in Central Africa

Political and economic development policies, as well as conflicts and civil unrest, have also played a role in declining food security in parts of the sub-region, as shown by the example of Cameroon in Box 2f.6. A comprehensive, integrated approach to improving food security and land quality is, therefore, a current environmental and developmental priority for central Africa. To this end, countries of the sub-region have ratified UNCCD. Chad and Cameroon are the only countries to have so far produced national reports, however, and Chad has also produced a National Action Plan. The CILSS, which encompasses Chad, has developed a sub-regional action plan to combat desertification (UNCCD 2001).

Cameroon and Chad have also developed NEAPs, which provide an overall framework for: improvement of land use; harmonization of land use policies; and environmental management. Implementation of these plans needs strengthening through additional resources and institutional arrangements. In Cameroon, the government has also embarked on a tree-planting programme, aimed at stopping the advancing desert.

Box 2f.6 Agricultural development in Cameroon

In 1972, the government of Cameroon embarked on a 'Green Revolution', whereby agricultural production and export was promoted, in order to boost the economy.Monocropping was encouraged, in order to increase the production of cacao, coffee, cotton and rubber, which were fetching high prices on the international markets. Fertilizers and pesticides were subsidized (by up to 65 per cent and 100 per cent respectively), which attracted many farmers to this style of input-dependent agriculture.

However, in 1986, the value of cacao and coffee fell drastically, plunging the country into economic crisis. Subsidies were completely removed, and the use of agrochemicals declined, together with soil fertility. Not only did farmers suffer from lost revenue for their products but, because they had been encouraged to grow crops for export, there was a national deficit of cereal staples. The country had to import food and to request food aid, which has subsequently disrupted local production and food security. For example, imported rice was sold at a lower price than local farmers could produce it,making rice farming unviable.

Consequently,many farmers abandoned their land and migrated to urban centres, seeking greater income and food security. In 1990, the government embarked on a comprehensive research and development programme to improve food security and land management. The approach was for agricultural extension workers to engage with local farmers, and to develop affordable means of improving productivity, food security and soil fertility. A number of local level projects have been successfully implemented, encouraging farmers to use organic matter, such as animal dung, instead of expensive inorganic fertilizers, and to encourage crop diversification and rotation, and agroforestry. Some farmers have been able to produce sufficient quantities to sell in local markets, and assistance in marketing is provided through the non-governmental organization (NGO) network.

Source: SANE 1997