Soil degradation is clearly one of the most pressing problems facing man kind. A continuation of soil degradation will eventually lead to a loss in crop productivity even though fertilizers and other inputs often result in increased yields in the short term. Soil degradation also leads to environ mental pollution. A decrease in soil quality invariably leads to a decrease in water quality, and often in air quality. While there is a clear consensus that soil degradation is a major problem, the literature on this subject leaves numerous baffling questions. If statis tics on land degradation are...