Studies on Salinity and Water Content of Soils - Geoelectrical Approach

Field investigations carried out using the earth resistivity meter for studying variations of salinity and water contents of soils in the vadoze zone of Delhi soils are presented. Variations in the salinity levels have been interpreted through bulk soil electrical conductivity (EC_a, measured by the resistivity meter), electrical conductivity of soil saturation extract (EC_e) and other soil-water parameters, EC_a values were also used to estimate the soil water contents in a soil profile. The spatial variation of EC_a indicates an exponential relation with the corresponding EC_e values and EC_a values in a soil profile has curvilinear correlation with soil water contents. With prior calibration, the resistivity meter can be used to estimate the soil profile water contents as well as to study the variation of soil salinity over a larger area. The method is non-destructive, rapid and gives reproducible results.