Overview of salt-affected areas in Latin America: Physical, social and economic perspectives

Abstract

In Latin América (LA), as well as in other parts of the world, salt-affected soils, both saline and sodic, are found under dryland and irrigated conditions, with negative consequences for the environment, for crop productivity and for animal and human health. Additionally, some tropical coastal and river delta areas have developed saline acid soils. Most of the salt-affected areas have extended under natural conditions. However, the development of affected areas as a result of human-induced processes, mainly associated with hydrological changes caused by irrigation and drainage practices, is increasing. This process negatively affects, sometimes irreversibly, the productive capacity of some of the best soils in many countries of LA, with important economic impacts and social consequences. Although recent estimates of the extension and distribution of human-induced salt-affected soils in LA are not available, there are clear indications that both problems, salinity and sodicity, under dryland and irrigated conditions, have been and are presently increasing in many LA countries. A country-by-country overview of soil and water salinity and sodicity is presented in this chapter, focusing mainly on irrigation and drainage problems.