C. Systems approach

Although general principles may be the same, technological packages (systems) for the sustainable management of soil and water resources are site-specific and depend on farming/cropping systems, farm size, the availability of essential inputs, and socio-economic factors. Locale specific and on-farm synthesis of packages is needed on the basis of the components and sub-systems described above. The agronomic productivity, economic profitability, and ecological compatibility of such packages need to be assessed through research. The systems research is conducted preferably on ,benchmark" soils of "ecological regions". By so doing, the agro-economic productivity of different production systems can be related to soil and climatic characteristics. Systems research necessitates a pan-disciplinary approach involving scientists with expertise in soil science, hydrology, climatology, agricultural mechanization, agronomy, plant improvement, pest management, economics, sociology, and anthropology. Results obtained from field experimentation can be validated against predictive models. The latter may be biophysical models, economic-productivity models based on linear programming, or statistical models based on systems analysis of, empirical data. The alternate agronomic approach is field experimentation on a step-by-step gradual improvement level, by substituting the component that is the major constraint to crop and animal production. Identification of, the major constraint and alleviation through technological options are once again topics of on-farm research. The agronomic approach is a long-term strategy aimed at transforming low-input subsistence farming into science-based commercial agriculture. Researchable priorities in this approach involve an assessment of the components or subsystems outlined in three stages (i.e.. traditional farming, improved farming, and commercial agriculture). In addition, specific research priorities should be given to soil and crop management practices that increase the efficiency of water and fertilizer use, and restore eroded and degraded lands. There is also a need for more research into the development of high-yielding crops/cultivars through biotechnology.