Genesis of Non-vertic Deep Black Soils in a Basaltic Landform of Maharashtra

Deep black soils (> 1 m) are developed in the narrow entrenched valley floor in the Jamni/Tamasvada watershed of Wardha district of Maharashtra. Despite their physical, chemical and mineralogical properties being similar to those of Vertisols in the basaltic landscape, the soils lack vertic characters, especially the slickensides. Lack of slickensides is attributed to the young nature of the soils as evidenced by the poor plasma separation. Role of factors that are hitherto known to impair the swelling of smectite is discounted. It appears that the shrinking and swelling of clay smectite need to continue at least for 550 years after the stabilization of the valley. The study thus points out the importance of time factor in the pedogenesis of Vertisols.