DO INCREASED COMMODITY PRICES LEAD TO MORE OR LESS SOIL DEGRADATION?

In this paper, a dynamic economic model is used to analyze the conflicting impacts of crop increasing/land degrading inputs with those of soil conserving/crop reducing inputs in problems of soil degradation in agriculture. Soil is a renewable resource that is generated naturally at a slow, essentially autonomous rate. Cultivation enhances crop production and degrades the soil, while conservation is unproductive for the crop but improves the soil resource. If the effects of cultivation dominate the effects of conservation in the soil dynamics, an increase in the price of the crop accelerates the rate of soil degradation In the short-run and decreases the long-run stock of the soil resource. On the other hand, if the effects of conservation dominate the effects of cultivation, an increase in the price of the crop decelerates the rate of soil degradation in the short run and increases the long-run stock of the soil resource. It is shown that subsidies on conservation activities or taxes on cultivation intensity may well decrease the long-run soil stock, although strong conditions must be satisfied for either of these results to hold. It also is shown that a reduction in the real discount rate or a direct per unit tax on soil losses is certain to increase the long-run soil stock and reduce the short-run rate of soil degradation