World’s Soil Resources

SOLONCHAKS (Salids)
Solonchaks (Figure A 8) are characterized by their high salt concentration, expressed by the electrical
conductivity of the saturation extract (ECe) that exceeds 15 dS m -1 (or > 8 dS m -1 when the pH is ≥ 8.5). The
presence of salt crystals and hydromorphic features are indicators of Solonchaks. The dominant soil processes
involved in Solonchak formation are salt accumulation and the development of hydromorphic features.
These soils generally occur in inland river basins and very flat or depressed areas which have a source of
soluble salts, such as salt-bearing parent material or a shallow saline water table. They also occur in coastal
lowlands. Generally they are formed in arid, semi-arid and sub-humid climates where rainfall is less than 500
mm yr -1 and the evaporation exceeds the rainfall. The vegetation consists of salt tolerant grassland, bushes or
mangroves.
Globally the extent of Solonchaks has been estimated at 260 million ha; they occur mainly in the drier parts
of North America, northern Africa, the Middle East and central Asia, South America and Australia.
Solochaks are typically used for livestock farming or highly adapted irrigation farming. The vegetation on
Solonchaks provides ecological services such as coast protection, grazing land and a source of wood. After
leaching the salts and with drainage, these soils can be turned into cropland.
Status of the World’s Soil Resources | Main Report Annex | Soil groups, characteristics,
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distribution and ecosystem services