Changes in Soils Around Urmia Lake: Physicochemical and Mineralogical Properties

Differences in physicochemical and mineralogical properties of soils close to Urmia Lake in two groups of soils (affected and unaffected by Urmia Lake), were studied in Dizaj-Dol region. Variance analysis of physicochemical properties of these soils showed that the values of OC and CEC in these two groups of soils were significantly different (P ≤ 0.1), and the values of EC, SAR, ESP and exchangeable Na of these soils were highly significantly different (P ≤ 0.01). However, soil depth and clay content in these two groups of soils were not significantly different. Clay mineralogical studies showed the presence of smectites, illites, kaolinites, chlorites and vermiculites in both groups of soils. Illites, chlorites and kaolinites are inherited from parent material, while smectites and vermiculites have pedogenic origin and have been formed via transformation of illite. In the soils which have been affected by Urmia Lake, neoformation from soil solution is the main origin of smectites. Comparision of clay minerals in the two groups of soils showed that the rising level of Urmia Lake during 1994-1995 caused the presence of high amounts of smectite and some hydroxy interlayer vermiculite in the soils affected by Urmia Lake.