تهیه نقشه رقومی ظرفیت تبادل کاتیونی در خاکهای زیر کشت گندم آبی در استانهای فارس، خوزستان و گلستان

This project was carried out to investigate the status of cation exchange capacity (CEC) of soils in selected areas under irrigation wheat in Fars, Khuzestan and Golestan provinces. The project is a part of a research plan conducted in Soil and Water Research Institute of Iran, aiming to map soil physical and chemical properties. Direct laboratory measuring CEC for all study points designed in the research is very time consuming and costly. The main objective of this project was to develop alternative procedures to predict CEC from the available soil data. Clay, silt, sand, organic carbon (OC) content (% by weight) and pH were the main variable used. Regression models indicate that for Fars province: clay accounted 58% of variation in CEC for Marvdasht plain, %51 for Sarvestan and %63 for Kavar. In Koreii, %89 of variation in CEC could be explained by clay and OC. In Khuzestan: clay accounted 57% of variation in CEC for Shushtar plain, %47 for Ramhormoz, %54 for Dezful, %95 for Shoeibie, %91 for Sorkhe and %53 for Annaghche. Clay and SOC explained %79, %62 and %78 of variability in CEC for Shoshtar, Ramhormoz and Dezful, respectively. In Golestan: clay accounted 52% of variation in CEC for Bandar-e Gaz, %52 for Bandar-e Torkaman and %52 for Ali Abad. Clay and OC explained %78, %50 and %76 of variability in CEC for Bandar-e Torkaman, Gorgan and Kalale, respectively. The OC alone accounted for 61% of the variation in CEC for Bandar-e Torkaman and Kalale. Keywords: cation exchange capacity, soil properties, regression model, prediction