Some of the commonest methods for measuring salinization include:
- Electrical conductivity as a measure of salinity: Salinity in soils can be estimated conveniently from the electrical conductivity (EC) of a soil solution.
- Leaching fraction: Simple empirical approach developed by Shaw and Thorburn (1985) to predict salt leaching for dryland soils and which is also applicable to irrigation.
- Root zone salinity: Plants respond to salinity throughout the root zone, so it is useful to be able to convert measurements at various depths in the root zone into a single number that can be used when considering plant response.
- Sodicity in soils and waters
- ESP (Exchangeable sodium percentage), which is the proportion of sodium adsorbed onto the clay mineral surfaces as a proportion of the total cation exchange capacity
- SAR (Sodium adsorption ratio), which is the relative concentration of sodium to calcium and magnesium in the soil solution or (irrigation) water.
- Salinization mapping
Remote sensing, contact & non-contact ground-based geophysical methods to assess:
- The mass and extent of salt in the landscape can be estimated
- Areas of potential salinity hazard and salt loads likely to be mobilised under a wetter equilibrium
Commonly used remote sensing methods:
- Aerial photography
- Thematic Mapping (TM)
- Airborne multi-spectral scanner (MSS)
- Airborne geophysics.