Flood Affected Soils of Brahmaputra Valley and Their Suitability for Land Use Planning

Six typical pedons representing the sotlscape of flood prone area were studied to characterize, classify and evaluate their suitability and productivity for crop production. Soils, in general, are stratified, acidic, rich in organic cariJon and fine in texture, Upland soils, slightly affected by floods, show higher chroma with Fe-Mn nodules while severely flood affected soils occupying the lower topographic positions exhibit lower colour chromas (1–3) and mottles and these variations were attributed to magnitude of change in pedo-environmenl in dry and wet season and pH-Eh relationship. Soils of upland, levee, lowland and flat land are classified as Inceptisols as they show the formation of structural B horizon while soils of flood channels and meandering scars are Entisols with least profile development Slightly flood affected (upland) soils with average productivity a Fe marginally suitable for agricultural crops due to limitations of moisture, erosion and acidity. Soils of levee and meandering scar are productive and suitable for growing abu rice and other rabi crops in flood-free season. However, soils of flat lands, lowlands and flood channel are evaluated as poorto very poor for production of crops except rice due to severe overflow in rainy season Based on suitability rating, productivity index and other factors the land use plan is proposed.