Salination

Salination, or salinization, is the accumulation of soluble salts in soil or water, raising salinity. It can refer to the process or to the resulting condition. Salinity is the overall salt content, while salination describes salt buildup. Salination occurs naturally and through human activity and can affect agriculture, ecosystems, and water resources.

Natural processes contribute to salination through weathering of minerals and evaporation in arid regions, which concentrate salts in soils. Seawater intrusion into coastal groundwater introduces salts that can move inland. Some rocks release saline minerals over time, contributing to soil salinity.

Human activities also drive salination. Irrigation with saline or marginal water, poor drainage, and rising groundwater bring salts to the soil surface. Land clearing, mining, and high groundwater withdrawal can alter hydrology and promote salination.

The effects include reduced soil fertility and structure, stunted crop growth, and lower yields. Salinity can degrade freshwater ecosystems and water supplies. Salinity is measured by electrical conductivity and total dissolved solids in water, while soil salinity is often expressed as ECe (electrical conductivity of the soil saturation extract) or similar indices.

Management aims to prevent buildup and remove accumulated salts. Strategies include improving drainage and performing leaching with adequate quality water, applying soil amendments such as gypsum for sodic soils, selecting salt-tolerant crops, and optimizing irrigation scheduling. In some cases, desalination or water treatment is employed to reduce salinity of irrigation water or impacted water sources.