Characterization of Soils Derived from Mica-Rich Parent Materials in Two Toposequences

Three pedons each in two distinct toposequences in old landscape of the mica-rich belt of Bihar were selected for stuqies on their morphometric features, characterization and taxonomic classification. The first toposequence having steep slope gradient indicates intense weathering while second toposequence with gentle slope gradient shows mild weathering. Soils developed in the first toposequence indicate muscovite as the dominant primary mineral and biotite was so in the second toposequence. Steep slope gradient with almost rolling physiography in a toposequence exhibited significant changes in most of the soil features. The toposequence with certain value above a critical slope gradient and associated physiography is meaningful in bringing about significant changes in soil features. In the first toposequence. the soils are classified as Udic Ustochrept in the topographic high. Fluventic Ustochrept in the mid slope and Typic Ustorthent in the lowland while in the second toposequence, the soils are Dystric Fluventic Eutrochrept in the topographic high. Oxic Haplustalf in upland and Typic Ustifluvent in lowland.