salinesoil

Saline soil is a soil in which soluble salts accumulate in the root zone at levels sufficient to impair plant growth. The condition is typically identified by a high electrical conductivity of soil water extract (ECe). In many soil- and crop-science classifications, saline soils have ECe above 4 dS/m (at 25°C). The pH is usually neutral to alkaline, and the exchangeable sodium percentage is low, distinguishing them from sodic soils.

Saline soils form where evaporation concentrates salts and drainage is insufficient. Natural factors include arid and semi-arid climates, saline parent materials, and coastal saline intrusions. In agriculture, improper irrigation with saline or alkaline water and rising groundwater are common causes, leading to salt accumulation in the upper soil.

Common salts include chlorides, sulfates, and carbonates of sodium, calcium, and magnesium. Because salts draw water away from roots by osmotic effects, plant water uptake is inhibited even when soil moist. Salt-affected soils may show crusting, reduced structure, and in extreme cases, surface crusts, but do not necessarily have high exchangeable sodium.

Management aims to reduce salinity in the root zone by leaching salts below the root zone, improving drainage, and using quality irrigation water. In sodic components, amendment with gypsum (calcium sulfate) can replace sodium on the exchange complex and improve soil structure. Crop selection for salt tolerance is common, and irrigation scheduling helps prevent salt accumulation.

Saline soils are part of a broader salt-affected soil category that also includes sodic soils (high exchangeable sodium) and saline-sodic soils (both high salinity and high SAR).