Characterization of Some Aquepts Occurring in Assam Valley

Aquepts developed on the Brahmaputra alluvium in Assam valley are characterized by grey colour of the surface horizons with rusty thread-like mottles along the root channels. Gleying also appears in the subsurface B horizons. The soils are deep, slightly acidic in the surface, medium to poor in exchange capacities with higher clay in the subsurface horizon. Drainage problem as evidenced by soil characteristics, viz. gleying and mottles with high ground water table is common. All the soils overlie a sandy layer. Free iron oxides accumulate immediately above the sandy layers. The study indicates that the changes in the course of the Brahmaputra river and its tributaries could have influenced the formation of these soils.