Effect of Geomorphology on Physical, Chemical and Mineralogical Properties of Soils in Southern Ahar

Appropriate knowledge about soil properties is essential for sustainable land management. In the present research، soil physical، chemical and mineralogical properties in southern Ahar، the area affected by different landforms، were studied. Six soil profiles on the pediment (high land) and on the floodplain landform (low land) were dug and classified according to the keys of soil taxonomy 2010. Profiles located on the pediment showed higher degree of development based on higher clay content (especially kaolinite) and greater solum depth in comparison with flood plain or low land. Carbonates in the soils of both landforms are predominantly pedogenic، but inherited carbonates were observed more frequently in the pediment soil، which increased with depth. Electrical conductivity decreased downward in soil profiles located on the pediment landform while it increased in floodplain profiles. In spite of pH increase in the soils of both landforms، organic carbon decreased in these soils. Cation exchange capacity and organic carbon content in the soils of floodplain were higher than those on the pediment. Mineralogical analysis using XRD spectrums showed that chlorite، montmorillonite، illite، kaolinite and quartz are dominant clay minerals in the soils of the study area.