Land suitability evaluation has been carried out for irrigated wheat, barley and cotton in an area of about 15000 ha in Eshtehard region 60 km from Karaj. In order to have more dependable soil data, particularity to control soil boundaries and update the soil information, the soil reports were studied and four soil series (being the most important soils with regard to the coverage, agricultural activity and climatic conditions) namely, Eshtehard, Abdolabad, Jafarabad and Shoorghaleh were selected for more detailed soil survey. Nine soil profiles were studied and their morphological, and physicochemical characteristics determined. Climatic data from Karaj synoptic meteorological station as well as some other closeby meteorological stations have been used for climatological evaluation. Based on coverage, yield and climatic conditions, wheat, barley and cotton have been considered and compared in the present land suitability evaluation on the basis of an irrigated agricultural system. In this region, the most important limiting land characteristics are: microrelief, texture and structure, soil depth, coarse fragments, gypsum content, soil reaction, drainage as well as salinity and alkalinity. In the survey area climate classes determined for wheat and barley are suitable (S1) while for cotton moderately suitable (S2). Analysis of rainfall and ETO data reveals that the growing period is about 135 days, starting on November 2nd until 3rd March. Using the two parametric methods (storie and square root) for determination of land indices for the three crops, land indices for barley were always higher than those for wheat and cotton with the square root method being revealed to be more applicable of the two methods.
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