MINERALOGICAL CHARACTE-RIZATION OF SOILS IN PLANTATION FOREST OF EAST KALIMANTAN, INDONESIA

Abstract

Soil minerals including primary mineral and (secondary) clay mineral play an important role which has greatly contributed in determining the properties of soils and availability of soil nutrient reserve in soil. The objective of the study was to identify of clay minerals and primary minerals (sand fraction) at forest plantation area in East Kalimantan, Indonesia. The mineralogical composition of fine sand fraction of soils was identified using a polarizing microscope (PM). The mineralogical composition of clay fractions was determined using X-ray diffraction analysis (XRD). The research plot is circular with an area of 0.05 ha and a radius of 12.6 m. Four soil sample from four plots collected for soil mineral analysis. The results showed that the clay fraction in plot A 45 has moderate amounts of kaolinite and vermiculite, trace amounts of goethite and illite. Plot A 34 was dominated by kaolinite, small amounts of vermiculite, trace amounts of illite. Plot A 36 was dominated by kaolinite, small amounts of vermiculite and illite, trace amounts of goethite. Plot A 33 was dominated by kaolinite small amounts of vermiculite and quartz. Compositions of Sand fraction at study area were dominated by resistant minerals (quartz).

Keywords

• quartz
• vermiculite
• primay minerals
• illit
• clay minerals
• kaolinite
• industrial plantation forest