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In land suitability studies the relationship between land use and its use type is determined based on sustainable principle and production content. Irrigated wheat, alfalfa and potatoes are the most important crops in Kurdistan province which maps of land suitability and predicted yield can help to select the best land unit to plant the important crops. The purpose of this study was to determine the land suitability index and predicted yield for irrigated wheat, alfalfa and potato to prepare their map through traditional and geostatistical methods. The study has area of 6500 hectares which located in Ghorveh region. At first, the land unit components map is provided by Mahler's physiographic method then based on it, 17 representative soil profiles in each land unit component were dug, described and sampled. Moreover, 105 auger samples also were taken at three depths (0-20, 20-50 and 50-100 cm). In all samples, soil texture, acidity, organic carbon, carbonat calcium, gypsum, ESP, electrical conductivity and gravel were measured. Land suitability index of irrigated wheat, alfalfa and potato were calculated using climatic, soil and topography characteristics. Then, traditional map of land suitability class of these crops was prepared based on the land unit components map. Land suitability map also was prepared using a geostatistical technique and its accuracy was compared to traditional map. In addition, potential and predicted yield of irrigated wheat, alfalfa and potatoes were calculated based on FAO model. The study area had about 34.88%, 36.61% and 39.08% N2 class (for irrigated wheat, alfalfa and potato, respectively), 21.72%, 6.22% and 60.92% N1 class (respectively for irrigated wheat, alfalfa and potato), and 43.40%, 57.17% and 0 % S3 class (for irrigated wheat, alfalfa and potatoes, respectively). The major limitations of the area for cultivation of these crops are mainly topography, gravel and pH. Potential production content (9.01, 23.32 and 51.85 t / ha) were calculated for irrigated wheat, alfalfa and potatoes, respectively. Kappa index results showed that geostatistical land suitability map (0.24, 0.23 and 0.18 for irrigated wheat, alfalfa and potato, respectively) had less accurate compared to the traditional land suitability map (0.49 0, 0.46 and 0.36 for irrigated wheat, alfalfa and potatoes, respectively. The results also showed that the highest values of land suitability index and predicted yield were observed in piedmont plain and plateau.
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