Farming, like pastoralism, has suffered from negative stereotypes whose roots lie in colonial incomprehension of the ecological and economic constraints under which it must operate. Aubréville's caricature of agricultural land use in the savannas of West Africa (chapter 2) contains two of the main elements of the stereotype: first, shifting cultivation, with its partner in crime, bush-burning; and second overcultivation, exposing the soil to erosion by wind and water, thus depleting its nutrients. A third element was the practice of interplanting in crop mixtures, long thought to be inefficient in terms of labour use, technology and yields.

In this chapter the nature of risk in dryland farming is explored, in order to answer the question: can the concept of instability, or disequilibrium, be usefully applied to understanding semi-arid farming systems?

Rainfall variability

Rainfall variability – within seasons between seasons and over several years – plays as important a part in defining risk for the farmer as it does in managing the rangelands. The coefficient of variability of the rainfall tends to decrease as the average amount received each year increases. The regimes under which farmers operate are therefore subject to less extreme variability than those of the arid rangelands. However, it does not follow from this that the risk to their livelihoods is diminished, more especially as dryland farmers are not able to choose less risky environments in which to work.