PEDOTRANSFER FUNCTION MODELLING OF SOIL WATER CHARACTERISTICS FOR PIGEON PEA PRODUCTIVITY IN LATERITIC, RED, AND BLACK SOILS

Abstract

Field capacity, permanent wilting point and Available water contents are the three vital hydrological properties which determine the retention and availability of water for crop growth. These properties are difficult to measure and time-consuming, but can be easily predicted from the available basic soil information like texture, organic carbon and pH.

Materials and methods: In selected geographical area of Agro climatic zones I, II & III of Karnataka, three types of soils namely Red, Lateritic and Black soils were selected for study.  Pedotransfer functions were developed for field capacity, permanent wilting point and available water content for these three types of soils. Cross-Validation of model using coefficient of determination (R2), root mean square error (RMSE) and mean error (ME) was carried out and the results were found to be satisfactory with low RMSE and higher R2. The developed PTFs are useful in predicting soil hydrological properties of respective soil types.

Result and discussion: The linear regressions for crop yield in lateritic, red and black soil series indicated that the basic soil properties viz. clay and organic carbon together contributed to the crop yield to the tune of 89.9 and 99.7 per cent in red and black soils, respectively whereas in lateritic soils sand and organic carbon together caused the 97.6 per cent variation in crop yield.