ECe prediction from EC1:5 in inland salt-affected soils collected from Khorat and Sakhon Nakhon basins, Thailand

We estimate the electrical conductivity of saturated soil paste extract (ECe) from electrical conductivity of a 1:5 soil-water dilution ratio (EC1:5) in Northeastern Thailand. Soil samples of various textures and salinity collected from Sakhon Nakhon basin were used to develop multiple regression models, from which the linear model was chosen and was validated on soil samples from the Khorat basin. Comparison with previous models indicated that most linear models gave a good fit, but the non-linear models either over or underestimated the measured values. The models performed very well for low values of ECe ((-1)), while the prediction errors increased significantly for ECe levels >35 dS m(-1). The present model performed well at various ECe levels and can be used to predict salinity levels for soils weathered from salt deposits in sedimentary rocks with similar rock formation in countries like Malaysia, Vietnam, Cambodia, and Laos.