Pedotransfer Functions for Predicting Soil Hydraulic Properties in Semi-Arid Regions of Karnataka Plateau, India

Soil hydraulic properties are important for irrigation scheduling and proper land-use planning. Field capacity, permanent wilting point and infiltration rate are the three vital hydraulic properties which determine the availability and retention of water for crop growth. These properties are difficult to measure and time-consuming, but can be easily predicted from the available information like soil texture, bulk density, organic carbon content, etc. through pedotransfer functions (PTFs). PTFs were developed for field capacity and permanent wilting point for two different regions of Karnataka, viz. Northern Karnataka Plateau (512 soil samples) and Southern Karnataka Plateau (228 soil samples), separately. PTF for infiltration rate was developed using 100 soil samples for the entire Karnataka. Cross-validation techniques were used to validate the PTFs, and the results are satisfactory with low RMSE and higher R². The developed PTFs are useful in determining soil hydraulic properties of the semi-arid regions of southern India.