Estimating solution extract salinity from soil paste electrical conductivity - an evaluation of procedures

Abstract

The electrical conductivity (EC) of a saturated soil paste extract (ECe) is the standard soil salinity measurement used to assess plant salt tolerance. Recently, a less time consuming method for the laboratory measurement of ECe was proposed that estimates ECe from EC measurements made directly in the saturated soil paste (ECp). The method uses a soil EC model and two empirical relationships developed with American soils. The empirical relationships are used to estimate the surface charge component of EC (ECs) and the water content of the continuous liquid current flow pathway (Bwc) from the saturation percentage (SP). This paper demonstrates that the same method may be successfully applied to Riverine Plain soils of S.E. Australia. The empirical relationships determined with Riverine Plain soils differed slightly from those published for American soils and gave a small improvement in accuracy. The method reduces the labour requirement of ECe measurements by approximately half.