SPATIAL DISTRIBUTION OF SOIL SALINITY AND SODICITY IN A SEMI-ARID CLOSED DEVELI PLAIN OF TÜRKİYE

Abstract

Spatial distribution of salinity and sodicity in semi-arid closed Develi basin of Turkey was investigated and assessed by geostatistical methods. Soil samples were taken in 1500 ´ 1500 m grid system from three different depth segments (D₁ = 0-30, D₂ = 31-60 and D₃= 61-90 cm). Soil saturation paste extracts’ electrical conductivity (ECe), sodium adsorption ratio (SAR) and soil reaction (pH) were determined. Classical and geostatistical parameters were obtained and kriging maps were generated to assess spatial patterns of investigated variables. The greatest coefficient of variation (CV) was identified for EC and SAR in D₁ layer (177 and 416%) and the lowest CV was identified for pH in the all depths (between 5.3 - 47%). Variation of ECe and SAR for the soil depths was not found significant, but variation of pH was found significant (p<0.05). Develi Plain was exhibited largely saline-sodic characteristics according to the kriging maps of ECe and SAR. In kriging maps, SAR and ECe exhibited similar spatial patterns in all of the soil depths and the variables exhibited a distribution with maximum values at the lower altitudes in the mid-sections of this closed basin.