GEOSTATISTICAL ANALYSIS OF SOIL-SALINITY IMPROVEMENT WITH SUBSURFACE DRAINAGE SYSTEM

Spatial variability of soil salinity and hydraulic conductivity at Sam pla Farm of the Central Soil Salinity Research Institute (CSSRI), Karn al (Haryana), India was studied using a geostatistical approach. Measu rements were taken at distances of 50, 150, and 200 m along the X-axis and at intervals of 12.5 m for the first 300 m and then at intervals of 25 m from 300 to 375 m along the Y-axis. Variograms and autocorrelo grams were utilized to identify the degree of dependency of soil salin ity between pairs of measurements. Cross-semivariograms yielded better structured spatial variability than semivariograms for all three year s (1984, 1987, and 1990) of observation. Decreasing soil salinity was validated by the jack-knifing method. Mapping of soil salinity and hyd raulic conductivity did show the effect of drain spacing in confirmati on with varied range of hydraulic conductivity and soil texture in the region.