Saline Soil

Salinity is defined by the concentration of soluble salts in the soil solution rather than by texture, and can develop on almost any soil type given the right combination of climate, drainage, and water source. It is distinct from, though sometimes associated with, sodic soils, where high exchangeable sodium causes structural rather than primarily osmotic problems.

Osmotic effect

High salt concentration in the soil solution reduces the ability of roots to draw in water, even when soil moisture content appears adequate.

Ion toxicity

Specific ions such as sodium or chloride can be directly toxic to sensitive crops at high concentrations.

Drainage interaction

Poor drainage concentrates salts near the surface through evaporation and capillary rise, especially in low-lying or fine-textured soils.

Texture independence

Salinity can occur in soils of any texture class; the underlying cause is the salt content of the soil solution, not the mineral particles themselves.

Managing saline soils centres on moving salts below the root zone and preventing their re-accumulation, alongside matching crop choice to the salinity level present.

• Improve drainage to allow leaching of salts below the root zone
• Where water supply and drainage allow, apply enough water beyond crop needs to leach accumulated salts
• Select salt-tolerant crops or varieties suited to the local salinity level
• Where sodium accumulation is also a factor, gypsum applications are a common reclamation tool used under local agronomic guidance

Barley is among the more salt-tolerant cereal crops and is commonly grown on moderately saline soils. Sugar beet is also relatively salt-tolerant. Many other crops are considerably more sensitive and can suffer yield loss at salinity levels that barley or sugar beet tolerate well.

Soil salinity is assessed through laboratory testing of electrical conductivity, typically from a saturated paste extract or a standard soil-to-water extract. Local extension services or accredited soil laboratories provide the most reliable testing and interpretation for a given crop and region.