|Sustaining the Future. Economic, Social, and Environmental Change in Sub-Saharan Africa (UNU, 1996, 365 p.)|
|Part 3: Environment and resource management|
|Agricultural development in the age of sustainability: Crop production|
This paper has discussed the potential for developing sustainable plant production systems for Sub-Saharan Africa. Only a small fraction of the biophysical potential for crop production in Sub-Saharan Africa is exploited. Although the constraints on plant production are many, they can be reduced to three main focus areas: rainfall, soil related issues, and human resource management.
There is a need to develop methods of conserving the available water and to invest in water storage, particularly for those semi-arid areas of Sub-Saharan Africa where there is a serious lack of moisture. This requires investment, but approaches currently used by farmers (stone and plant barriers, surface catchments, tied ridges) need to be improved and inland valleys should be exploited. All these require more research. Agro-forestry species tolerant of acid soils and adapted to the semi-arid zone should be identified and evaluated for their usefulness in alley or related systems.
In the humid forests, the Guinea and moist savannas, and the highlands of eastern Africa, agro-forestry systems, multiple-cropping systems, and surface mulching using appropriate live mulch species need to be studied further. These have elements of sustainability that require additional research prior to their wide application. Of particular importance is the interaction of live mulches with soil moisture, especially in dry areas. With the increasing cost of imported chemicals, fertilizer research should be redirected to determining the minimum levels required for sustained yields and to augment nutrients generated through biological activity.
Holistic approaches to technological developments pay off in terms of their ease of adoption. Step-wise approaches to technology development, using farmers' current systems as the base, appear to have merits for the small-scale farmers of Sub-Saharan Africa. Research into whole farm systems requires a revision of the operational approach. Farm-level research is very complex and involves many interactions; it therefore requires multidisciplinary team efforts. Less rigorous but useful analytic approaches should be devised for interpreting data. Most of the farmers in Sub-Saharan Africa are women. Their neglect in resource allocation should be redressed by gearing efforts towards enhancing their productivity.
Finally, biotechnology may be the cheapest hope if it is applied to resolving some of the constraints, for example through multiplication of improved varieties, particularly clonal materials (Zok and Nyochembeng 1992), conservation of wild and exotic species, and breeding for disease and pest resistance and much other gene-related research. Regional laboratories to handle this specialized work need to be created, staffed, and funded for the mutual benefit of the countries of Sub-Saharan Africa, and special management procedures devised for the laboratories. Some existing laboratories - for example, the Jay P. Johnson Biotechnology Laboratory, Ekona, Cameroon, and the International Institute of Tropical Agriculture Biotechnology Laboratory at Ibadan, Nigeria - could be expanded to serve parts of the region, and the possibility of establishing others needs to be evaluated. Courses in biotechnology to acquaint researchers and policy makers with its potential (similar to the one designed by Ferguson et al. 1992) could be modified to fit Sub-Saharan African conditions and videotaped for popular use. Such a course could remind researchers and policy makers of the usefulness of cell biology in agriculture and of the basic training requirements.