Soil salinity is an important parameter in irrigation, drainage, and environmental studies. Determining the electrical conductivity of soil saturated paste extract (ECe) is a well-known method, but its use is limited because its production process is time-consuming and difficult. The 1:5 solution electrical conductivity (EC1:5) is an alternative simplified method. The aim of this study was to evaluate ECe-from-EC(1:5)conversion models. A total of 123 samples from 3 soil layers were analysed. The research was planned in two phases: 1) model evaluation in soil layers, 2) model evaluation in ECe categorized data. Results show that the linear model was the best model in the second layer (R-2= .66, mean absolute percentage error [MAPE] = 0.058), and the exponential model was the best in the other layers (R-2= .65 to 0.67, MAPE = 0.085 to 0.060). Also, exponential and linear regressions were the best ECe estimation models in the ECe < 4 and ECe > 4 categories, respectively. In addition, the conversion factor (f) for converting ECe and EC(1:5)was obtained as 3.7-13.9, 2.8-5.0, and 3.4-5.8 for three soil layers, respectively. Results show that the use of general recommendation tables forfwill lead to considerable error, and the factor must be determined specifically for each region. (c) 2020 John Wiley & Sons, Ltd.
