Spatial variation of chemical properties of colluvial-alluvial soils in central Black Sea Region

Soil spatial variation is an important factor to be regarded in land use planning and water and nutrient management in soils. In this study, spatial variation of some soil properties in an approximately 1400 ha area comprising the soils used by Black Sea Agricultural Research Institute were evaluated. One hundred soils samples were taken from 0-20 cm soil depth by random sampling scheme and analyzed for soil organic matter (SOM), cation exchange capacity (CEC), CaCO3, pH, and electrical conductivity (EC) in the laboratory. The spatial structures of soil properties were modeled by semivariograms and their surface maps were built by kriging interpolation of five soil properties, only CaCO3 exhibited normal-like distribution, and SOM and CEC were modeled with spherical, and others with Gaussion model. Lowest nugget effect occurred for EC and highest for pH, and EC and CaCO3 were strongly spatially dependent, while the others were moderately spatially dependent. Spatial pattern of soil properties were somehow similar one to another, and this was attributed to soil texture and land use, which occurred as common controlling factors of spatial variability of studied soil variables in the study area. The results have a potential to be used in sustainable land use planning and to guide growers in revising/adapting management practices (e.g. fertilizer use, irrigation, soil tillage, erc.) for mitigating land degradation, protecting environmental health, and saving resources