سهیلا سادات هاشمی

The salinity and alkalinity of soils is a major problems in arid and semi-arid that it’s considered. These soils including un arable land that it’s need identified for their reclamation. However, the purpose of this study is investigation of physical, chemical and micro-morphological properties of alkalin soils in Shoshab region. After sampling of eight profiles, physical, chemical and micro-pedological analyses were performed and the profiles were classified based on Keys to Soil Taxonomy 2014. The result showed that soil gypsum and calcite are increasing with soil depth increase. Soil pH was high but don’t change with soil depth. The presence of gypsum induce to change of soil texture toward silt and sand. The sodium content is more in surface horizons and it’s reducing with increase of soil depth. The high evaporation is cause to accumulation it in soil surface. Micromorphological observations including hypocoating, coating, loose continuous, dense complete and dense incomplete infilling of gypsum in voids and channels walls. Lenticular, prismatic, and allabasrtin of gypsum crystals observed in thin section. gypsum lenticular form was common in all thin sections because of xeric moisture regime in the region. The presence of gypsum and sodium in the area induce to angular and sub angular blocky micro-structures and weakly accommodate of aggregates. The common observed b-fabric in all thin sections was crystallitic form and in some case detected as undifferentiated.