Genesis and Classification of Soils in Segzi Plain (Iran)

A study was carried out to investigate the genesis and classification of soils in Segzi plain in the eastern of Isfahan province (center of Iran). Due to its specific geographic condition, Iran is located in the dry and semidry climatic zone. Aridisols are soils of the aridic moisture regime which occur normally in arid climates. For this study, a sum of 15 profiles was studied. Soil colors were defined using the Munsell soil color chart. Electrical conductivity, soil reaction, organic matter (OM) and the percentage of gypsum and calcium carbonate were measured. Mineralogical properties of the soils were analysed. The evidence provided by this experiment indicated that most of the soils were classified as Gypsic Aquisalids sub groups according to the Soil Taxonomy and as in Hypersalic Solonchaks soil units according to WRB classification systems. According to micromorphological analysis the studied soils have clay coatings (clay film), calcite infillings and gypsic infillings in selected soil profiles. Mineralogical properties showed that there were Mica, Palygorskite, Smectite, Vermiculite, Chlorite, Kaolinite, irregular mixed layer Mica?Smectite mineral, irregular mixed layer Chlorite?Vermiculite mineral, irregular mixed layer Chlorite?Smectite mineral and Quartz in the soils of Segzi plain.