Focusing attention on subsistence cultivators is one of the logical starting points for examining rural Africa from a geographical perspective. Such farmers, functioning within a physical setting that provides both opportunities and constraints, must depend for survival on a familiarity with environmental qualities and contend with extreme conditions. Within this situation an agricultural system must be designed to provide for current food consumption plus a surplus that will vary with local circumstances.
Both agricultural practices and environmental characteristics impinge, in turn, on systems of settlement and mobility. Neither the individual nor the farm family is static, but circulates within a defined area and may eventually relocate when circumstances require. When land is actually allocated, not only subsistence needs are taken into account, but also social regulations such as those concerning the distribution of homesteads relative to the distribution of fields.
Thus, this overview of the rural African will be concerned with a sequence of four interrelated factors: (1) the dominant mode of food production, (2) the environmental setting, (3) a scheme for organizing terrestrial space at a local scale, and (4) a systematic approach to migration. Within the context of these spatial and environmental factors, the process of change can be superimposed; operating gradually at first and then accelerating, especially during the last hundred years. As population density has increased, as land has become more scarce, and as the commercialization of agriculture has spread, the basic relationship of environment, production, settlement structure, and mobility have been modified. Simultaneously, the cultivator has been evolving into a peasant.