Maping of micronutrient concentrations for fertility management some agricultural lands using Geostatistics, northwest Iran

The goal of research was to study the spatial structure and mapping the spatial distribution of some soil micronutrients using geostatistics. For this propose, 390 soil samples were taken from agricultural soils in Maragheh located in southwest of East Azarbayjan. Soil samples were analyzed using standard methods and the amounts of available Iron (Fe), Zinc (Zn), Manganese (Mn) and Copper (Cu) were measured. Nutrient semi-variograms were developed and then a suitable theory model was fitted to data. The information generated from the fitted models was applied to make use of ordinary kriging and estimating the value of micronutrients in unknown locations. The results revealed that distribution of micronutrient data sets had no random pattern and there was a spatial correlation between micronutrient. Zn had a strong spatial structure (Nug/Sill=10.87%), but Fe, Mn and Cu had a moderate spatial structure. Semi-variograms of all the nutrients were fitted to exponential and spherical models. The maximum and minimum ranges were found for Zn and Cu with 3540 m and 15000 m distance, respectively. Generated maps showed that the studied arable soils were suffered from Zn and Fe deficiency, had an optimum level of Mn and an excessive amount of Cu. These maps can useful for agricultural soil quality management especially in large scale.