The Effect of Soil Texture on the Conversion Factor of 1:5 Soil/Water Extract Electrical Conductivity (EC1:5) to Soil Saturated Paste Extract Electrical Conductivity (ECe)

The electrical conductivity of soil saturated paste extract (ECe) is used as an indicator for estimating soil salinity. This method is time consuming and laborious and therefore, easier and faster methods are usually used with different soil/water ratios, such as 1:5 (EC1:5), for estimating the ECe. Usually, the relationship between ECe and EC1:5 is described by a simple linear empirical equation. The value of the conversion factor (CF) of EC1:5 to ECe is affected by the particular characteristics of the soil, such as its texture. The objective of this study is to investigate models that allow the inclusion of soil texture in the calculation of the CF, in order to improve the prediction of the ECe. A total of 148 soil samples with different soil texture and salinity levels were selected from three regions of Greece, and ECe, EC1:5, as well as clay and sand contents were determined. The results show that the CF can be estimated from an equation which incorporates the clay and sand contents through the soil saturation percentage (SP) and can give a fairly good prediction of ECe from EC1:5 (R-2 = 0.9887 and RMSE = 1.39 dSm(-1)).

Automated summary

The electrical conductivity of soil saturated paste extract (ECe) is commonly used to estimate soil salinity, but this method is time consuming. This study investigates a new model that incorporates soil texture to calculate the conversion factor (CF) between EC1:5 and ECe, resulting in improved prediction of ECe.