Advances in the ECe prediction from EC1:5

The standard measure of soil salinity is electrical conductivity (EC) of saturated soil paste extracts (ECe). However, measuring ECe is labor and time-consuming and the accuracy of ECe is dependent on individual skill. As an alternative, the electrical conductivity of the extracts of 1:5 soil:water ratio (EC1:5) is commonly used, and thus the conversion of EC1:5 to ECe is necessary for the practical use of EC1:5. Recently, a multiple regression model for the estimation of conversion factors (CF) using clay content and exchangeable sodium percentage (ESP) has been developed: CF = 7.179 - 0.084 × Clay + 1.096 × ln(ESP). In this study, the CF model was validated using unpublished data on EC (EC1:5 and ECe), clay content, and ESP that were obtained from 50 paddy fields (n = 100 including two depth) of five reclaimed tidelands located in the coastal areas of South Korea. The CFs ranged from 5.7 to 11.9, and the measured and predicted ECe were linearly correlated (r2 = 0.81, P < 0.001) with an error of 11.2%. Despite the potential errors, we suggest that converting ECe from EC1:5 using the CF model may be a feasible method for long-term monitoring of ECe with the consideration of the time and cost and inconsistent accuracy of ECe measurement as clay content and ESP are the basic soil monitoring parameters in saline soil survey projects.Correlation between ECe measured and ECe predicted from EC1:5.