Pedo-Transfer Functions for Saturated Hydraulic Conductivity of Cultivated Soils in the Mid Hills of Sikkim

In this study, pedotransfer functions (PTFs) are developed for saturated hydraulic conductivity (K_s) using multiple linear regression (MLR) technique for the cultivated terraced land of East Sikkim district, North East India. Soil samples were collected for 29 stations and K_s values were measured using the constant head permeameter. The various combinations of measured soil properties, including percentage of sand, silt, clay, bulk density (BD), particle density (PD), porosity, organic carbon (OC) content were used for the development of the models. The K_s value varied from 0.97 to 29.38 cm/day and the mean value was 8.04 cm/day in the study area. The correlation between predicted and measured values was found to be better for the combination, including five input variables. The results indicated a negative correlation of K_s with silt, clay and BD, whereas sand, PD, OC and porosity had a positive correlation. The recommended MLR model 5 consisting of five input variables for the prediction of K_s in the study area had R² values of 0.81 and 0.83 during model development and model validation, and showed goodness-of-fit with the observed K_s value. The PTFs developed in this study would be helpful for the planning and design of water resources structures in the hilly state of Sikkim.