Soil and mineralogical characteristics of rangeland around Parishan Lake of Kazeroon, Fars province

The purpose of this research was to study the morphological, physico-chemical and mineralogical properties in different physiographic units of rangeland soils of Parishan lake  area in Kazeroon, Fars province with soil temperature and moisture regimes of ustic and hyperthermic, respectively. To this end, four representative soil profiles were selected on plateaus, hills, piedmont plain and low land physiographic units. Laboratorial studies were carried out on each soil sample after being air- dried, compacted and sieved by a two-millimeter sieve. Based on the laboratorial data, the soils of the area were classified as Entisoils and Inceptisoils with ochric epipedon and calcic and gypsic subsurface horizons. The result showed that soil factors have not had a significant impact on soil evolution and development in the lands under study in Parishan lake, which are located in four physiographic units and under rangeland use due to the low rainfall and calcareous soils.  It seems that among the five soil forming factors, topography and time have played more prominent role. The XRD data for the less than 2 μm fractions of the studied soils indicated that the soils were similar in their clay mineralogy, mainly consisted of illite, smectite, chlorite and palygorskite but were different in content. Illite and chlorite were higher in plateau and higher content of smectite was observed in low land unit due to low drainage condition. The source of smectite mineral of the  area soils can be inheritance, neoformation and transformation. Chlorite, illite and quartz are inherited and the resource of palygorskite is mainly inheritance and neoformation in the presence of gypsum and calcit. Finally, most of the soil's chemical properties, including organic matter, EC and gypsum, have had an increasing trend from the plateau physiographic unit to the low land.