Estimation of Root zone salinity using SALTMOD – a case study

This study aims to estimate the Root zone salinity of salt affected areas of some parts of Gokak and Ramdurg taluks of Belgaum districts and Mudhol taluk of Bagalkot districts, Karnataka, India. The study area falls under semi-arid and drought hit areas. The hydro-salinity model ‘SALTMOD’ was applied for this study area, which computes the salt and water balance for the root zone, transition zone and aquifer zone. The model was applied to the selected agriculture plots at Gokak, Mudhol and Ramdurga taluks for the prediction of root-zone salinity and leaching efficiency. The model simulated the soil-profile salinity for 20 years under different conditions, viz. with subsurface drainage and without subsurface drainage. The salinity level shows a decline with an increase of leaching efficiency. The leaching efficiency of 0.2 shows the best match with the actual efficiency under adequate drainage conditions. However, without drainage there is a drastic increase in salinity over the years there by indicating the necessity of artificial drainage system .The model shows a steady increase, though at a slow pace over the years, reaching the levels up to 5.8 ds/m to 9.8 ds/m at the end of the 20 years period. If suitable drainage system is not provided, the study area will further get salinized thus making the land uncultivable. From the present study it is evident that it is necessary to provide proper drainage facilities to control the salinity levels in the study area.