Salinity and alkalinity in soils of the Arid Region of Tenerife, Canary Islands, Spain

Saline-sodic soils in the low-lying areas of the Canary Islands have limited productivity. This work is intended to further knowledge of the origin and nature of the salinity-sodicity that affects soil quality in an and zone of the Tenerife Island. The surface horizon of non-cultivated soils was sampled, and properties related to the saline-sodic state of the soils were analysed together with their relationship to diverse environmental factors: proximity to the sea, altitude, topographic position, past land use, geological formation. The results show that salinity-sodicity is related to sea-born salts, with sodicity-alkalinity derived from the presence of phonolitic ash (pumice) as the material of origin (only when salinity is low). Salinity-sodicity appears to have been influenced by the abandonment of farmland by cultivation. Sodic-alkaline soils also experience low-fertility problems.