Investigation of spatial variability in some soil characteristics in Fenerköy river basin (Silivri-İstanbul) by using geostatistics

This study was carried out in Fenerköy/Silivri district to analyse the spatial variability of some soil characteristics and comparison with different geostatistical methods. Soil sampling (0-20 cm) was conducted by grid sampling method from about 1600 ha study area and 240 samples were taken. Soil texture, pH, EC, CaCO3, organic matter, available phosphorus and potassium anayses were carried out in all samples with the aim of sustainable agriculture model. According to descriptive statistics results the coefficient of variation (CV) was determined. The greatest coefficient of variation was found for avaiable phosphorus (CV= %168,52), the lowest for pH (CV= %5,15). Best fitted variogram model identified for each for parameter before kriging methods. The methods, generally used in soil science which were named as IDW (deterministic), simple kriging and ordinary kriging (geostatistics) were compared. As a result of this comparison; sand, pH, extractable potassium parameters were mapped by ordinary kriging method and the other parameters were mapped by simple kriging method. According to sustainable agriculture model of the total study area 0,03% (0,46 ha) is highly suitable, 32,73% (516,61 ha) is moderately suitable, 67,12% (1059,20 ha) is marginally suitable, 0,12% (1,87 ha) is currently not suitable for agricultural production.