Computer Based Geostatistical Strategies in Assessing of Spatial Variability of Agricultural Phosphorus on a Sugarbeet Field

Evaluating the computer based geostatiscial methods will eliminate the unequal soil phosphorus variability on agricultural fields. These methods may commonly be useable for simulation of spatial variability of agricultural phosphorus on these areas. It will be valuable for balanced phosphorus consumption by crops and reduced environmental pollution. In this study, topsoil (0-20 cm) and subsoil (20-40 cm) samples based on 20 X 20 m grids were collected from the plots under the sugarbeet plants. Plant samples were also collected from the same plots. The soil and plant samples were prepared for analysis. The data concerning with phosphorus levels were analyzed through Kriging interpolations, which are the computer based geostatistical methods. To achieve cross-validation, distribution percentages were formed by using all Kriging methods. As a result of cross validations, the best optimal method was found to be Simple Kriging interpolation method for each data group (Ordinary RMS, plus or minus 6.38, Simple RMS, plus or minus 5.98 Universal RMS, plus or minus 6.41). By using this method, semivariogram models were tested, and exponential semivariogram model was found as the most suitable model for the experimental data group. Soil and plant phosphorus distribution faces were adequately determined by using selected simple Kriging interpolation method and suitable semivariogram model. These distribution faces were processed by software 3D analyst modul to enable three dimensional mapping.