DETERMINING THE SOIL QUALITY INDEX IN THE BATUMI DELTA, GEORGIA

Abstract

The soil quality index is a quantitative assessment concept and it is used in the evaluation of ecosystem components. Because of the high potential for agriculture and biodiversity, deltas are the most valuable parts of the ecosystem. This study aimed to determine the soil quality index (SQI) in the Batumi Delta, Georgia. For this purpose, the study area was divided into five plots due to their morphological positions (L1, L2, L3, L4, and L5). A total of 125 soil samples were taken for analysis including clay content (CC), silt content (SC), sand content (SaC), mean weight diameter (MWD), aggregate stability (AS), amount of water retained under -33 kPa (FC) and -1500 kPa (WP) pressures and organic matter content (OM). These properties were used as the main criteria, and the Analytic Hierarchy Process (AHP) and Factor Analysis were used for weighting them. Sub-criteria were scored using expert opinion and the linear score functions, such as “more is better” and “optimum value”. For determining SQI, the additive method (SQIA), the weighted method with AHP (SQIAHP), and the weighted method with factor analysis (SQIFA) were used. The resulting SQI scores of the three methods were ordered as SQIAHP>SQIA>SQIFA, but these differences were not significant. However, the SQI scores of the plots (p≤0.01) showed statistically significant differences and were ordered as L5>L4>L3>L2>L1.