Dispersive and sodic soils

Dispersive or sodic soils are common in the south-west agricultural area of Western Australia where they occur mainly as duplex or gradational profiles. Sodic duplex soils are particularly susceptible to waterlogging, as they are commonly on broad, flat landscapes with poor drainage. Other problems on these soils include reduced plant growth, increased erosion risk, and poor trafficability when wet. These soils are difficult to manage, and can have multiple constraints to crop and pasture growth. There are several options that improve soil structure, and potentially improve crop and pasture growth.

Articles

  • It is not always easy to identify the degree of dispersion or sodicity in soils. The choice of suitable management depends on knowing the soil sodicity and whether dispersion is a problem.

  • Dispersive (sodic) soils are common in the south-west agricultural area of Western Australia, where they occur mainly as duplex or gradational profiles.

  • Dispersive soils are common in the agricultural area of Western Australia, where they occur mainly as duplex or gradational profiles.

  • This page explains the terms and importance of soil structure (aggregate stability), cation exchange capacity, calcium to magnesium ratio and exchangeable sodium percentage.

  • Waterlogging causes soil structure collapse in sodic soils, because the clay particles holding soil particles together disperse.

  • Soil aggregate stability is the ability of a soil to regulate the movement and storage of air and water throughout the soil profile, and the profile is determined by the soil make up of sand, silt