ABSTRACT
This paper reviews over 80 studies on food security-related impacts of soil degradation in developing countries, and predicts future degradation concerns in the context of expected changes in population and agricultural economies. The analysis concludes that soil degradation is not likely to threaten internationally traded food supplies between now and 2020, due to the global capacity for substitution and the dominance of temperate producers. But it could have significant effects on national agricultural supply and prices in many countries. The greatest impact will be dampened economic growth from lower farm incomes, especially where agriculture is the ‘engine of growth’ The greatest threats to the welfare of poor farmers will be in the densely populated marginal lands of sub-Saharan Africa and South Asia. Predicted agricultural land loss does not threaten global wealth in soil assets, however for countries with a limited land base, conserving farmland quality is essential to long-term food security. The most serious degradation-related problems will be found in densely populated marginal lands. Second in importance will be salinization and waterlogging in irrigated lands. Agricultural land quality and preservation in urban areas will become more problematic. Soil degradation in lightly populated marginal lands is unlikely to pose society-wide economic (as distinct from environmental) costs.
