Division of Soil Resource Studies, National Bureau of Soil Survey and Land use Planning (ICAR), Amravati Road, Nagpur, 440010, Maharashtra, India.
Representative paddy-growing soils of four districts in the eastern Vidarbha of Maharashtra were studied for their mineralogy and genesis. Paddy-growing soils represent relatively humid part of the eastern Vidarbha (MAR ranging from 1312 to 1551 mm) with altitude ranging from 173 to 300 m above MSL. The mineralogical investigation indicates that these soils have smectitic clay mineralogy along with smectite-kaolin (Sm/K) interstratified minerals. Smectite is transformed to Sm/K due to the weathering process. Smectite was the first weathering product of plagioclase feldspars in an earlier humid climate. The formation of Sm/K interstatification is a post-depositional clay mineral transformation. The genesis of all the minerals of all the soil indicated detachment of weathered materials of basalt and their subsequent transportation and deposition in the valleys and depressions. These soils continue to exist in the valleys. Due to poor drainage conditions the smectite minerals remained in the pedo-environment and only transformed to Sm/K interstratified minerals.