EUROSOIL 2021, Geneve, İsviçre, 23 - 27 Ağustos 2021, ss.90
As increasing food need is considered, the importance of Alluvial soils, which have high productivity potential in agricultural production and develop on Fluvial terrains, put these soils forward. Since variability of soil properties in fluvial terrains occurs in short distances, this situation induces some problems in the management of these soils whose properties are not completely determined. The objective of this study was to determine the spatial variability of soil quality by considering the productivity levels of the soils located in the lower zone of Aksu River in Antalya province under the Mediterranean climate. Solak village lands in Aksu district where Aksu River deposits spread are selected as the study area. In the study area, three different physiographies, namely; flood plains, river ridge, and lateral river alluvials connecting to flood plains were identified. Disturbed soil samples were randomly collected from 75 points at 0-20 cm soil depth on 1625.3 hectares land which were previously surveyed. In soil samples, sand, silt, clay, pH, electrical conductivity, lime, organic matter, cation exchange capacity, available phosphorus and extractable potassium were analyzed. Soil quality indicators were scored using Standard Scoring Functions and were combined in a Soil Quality Index (SQI) by giving weight to the quality indicators with the Analytic Hierarchy Process. The spatial variability of SQI was modeled geostatistically with GS+ and mapped with ArcGIS. “Spherical” model was chosen as the best model as it gave the highest R2 (0.801). The spatial dependence was determined as 32.4% by using the Nugget (42.5) and Sill (131.0) values. Soils with low quality were determined with 50.1% at most in the study area soils evaluated in five classes in terms of SQI levels. As the quality level increased, distribution areas of the soils decreased and medium quality soils with 44.8% and high quality soils with 5.1% were obtained, respectively. As a result, it was concluded that current management methods affected soil fertility levels adversely and changes should be made in the management methods.