Soil Fertility Evaluation Based on Soil K, P and Organic Matter Factors for Wheat by Using Fuzzy Logic-AHP and GIS Techniques

Nowadays, fuzzy technique is used to prepare the map in different sciences, extensively. With due attention to important role of soil fertility in modern agriculture, the preparation of soil fertility map seems to be necessary to plan for appropriate using of fertilizers for crops. This study was conducted to prepare a distinct map for evaluating soil fertility according to soil available K and P, and soil organic matter factors in Shavor region in Khuzestan province. The fuzzy technique and the Analytic Hierarchy Process (AHP) were used for mapping soil fertility into Geographic Information System (GIS). For this, the amount of soil organic matter, and available soil phosphorus and potassium obtained form 282 profiles of soil, as the input data, were used. In the first stage the interpolation of data was done by Inverse Distance Weighting (IDW) model into GIS. Then a membership functions was defined for each factor. Finally, the map of soil fertility was prepared by using AHP technique into program of Expert Choice with adjustment rate of 0.05. Results showed that 51, 26, 12 and 11 percentage of lands were classified base on soil fertility into groups of very weak, weak, moderate and suitable, respectively. As a final result, this types of distinct soil fertility map can able us to manage the appropriate using of fertilizer.