the comparison of micromorphological properties of saline – sodic and nonsaline-nonsodic soils around the urmia lake

in order to comparision of the micromorphic properties of saline-sodic and nonsaline-nonsodic soils in the west of urmia lake, four soil profiles (2profile in saline-sodic soils and 2profiles in nonsaline-nonsodic soils) were investigated. these profiles were described and sampled using standard methods. soil samples were used for physico chemical analysis and undisturbed and oriented samples were used for thin section preparation. thin sections were studied using polarizing microscope in ppl and xpl lights. thin sections studies showed that saline-sodic soils are structure less (apedal), and their voids are mostly vughs and channel and as a result, their, nonsaline-nonsodic soils are pedal with compound packing voids, vughs and planar voids and as a result, the b.fabric in these to group of soils is crystallitic. in saline sodic soils pedofeatures are illuvial clay coatings, salt accumulations including coatings and infillings of halite in channel and vughs. these pedofeatures were not seen in nonsaline-nonsodic soils. organic coatings were seen as black colored films on peds and in some cases mixed with groundmass of saline-sodic soils.calcium carbonate accumulations as nodules and coatings and nodules and coatings of iron and mn oxides were seen in both saline-sodic and nonsaline-nonsodic soils.