Some characteristics of clay minerals of soils in the southern region (provinces of Daraa, Sweida)


Abstract in English

This study was achieved to identify some characteristics of clay minerals of soils in the southern of region (provinces of Daraa, Sweida). Several soils profiles were selected, forming a toposequence, including the western slope of Jabal Al Arab and part of Huran plateau which rise about 500-1200m a.s.L. and rainfall between 250-350mm. These soils usually are planted with rainfed crops and some trees. Three samples were collected from each profile at depth 0-25 cm, 25-50cm and 50-100cm in order to determine some physical and chemical of soli characteristics and x-ray and Differential Thermal Analysis (DTA) were applied to determine the mineralogical composition of clay minerals. Results indicated that the soils had an clayey texture (37.9 % in Tafas Dr2 to 67.5% in Tal al Haded SW2), rather high CEC (35-49.4) meq /100g soil, neutral pH in Sahwa blata SW1 soil (7.1) to slightly alkaline pH (8) in other soils, low content of organic matter (1)%. CaCO3 ranged of (3.16)% in Sahwa blata SW1 soil to (25.35)% in Tafas Dr2. Cacium was the dominant cation on the exchange complex (33.11mq/100g) in TafasDr2, and followed by magnesium (13.99 mq/100g) in Tal al Haded SW2. Mineralogical analsis by x-ray and DTA showed the presence of three main clay minerals, Smectites (montmurillonite), Kaolinite and Mica (probablly illite).

References used

Abou Nukta, F. 1982. Soil of huran basin classification. Agr. Abs. Soil. Sci. Soc. Am.USA
ACSAD. (1980). Tour guide, soil classification workshop. 2-4 April. ACSAD\SS\R28 Damascus. 170 P
Allen, B. L and D. S. Fanning. 1983. Composition and soil genesis. In: Pedogensis and soil taxonomy. I. Concept and interaction. Ed. by L. P. Wilding et al, Elsevier, Amsterdam, p. 141-192

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