Soils of the Rainfed Region of West Bengal and their ProductivityPotential Appraisal

摘要

Funnel-shaped topography, severely affected by erosion and moisture stress, is the unique feature of Chhotanagpur plateau. The information on the characteristics of soils on this kind of landscape is very meager. Morphological, physical and chemical properties in six typifying pedons, three on each sides of the funnel-shaped transect were studied to bridge the gap of information. Results indicated that grades of yellow colour tended to be redder down the slope topographically in the soil profiles ofone side of the transect and the surface horizons on its other sides. Clay, pH, cation exchange capacity, base saturation and water retention both at the field capacity and wilting point followed the similar trends. Movement of finer particles from upperto the lower topographical situation was the reason for such a change. However, such relationship was not consistent between topography, macro and micronutrients. Sub-surface redder colour on one side of the transect was attributed to the extensive erosion, bringing soils of Archaean period closer to the surface. Thick and patchy argillans on the ped faces confirmed that downward movement of clays had also taken place during pedogenesis. Soil water retention characteristics indicated that the influenceof drought may be pronounced and cascading on the elevated topography. Land use change has occurred from groundnut on elevated topography to the paddy on the lower part of the landscape. Soil productivity and productivity potentiality increased topographically from upper to the lower element of the landscape. The coefficient of improvement (C.I.) varied from 1.3 to 2.3 indicating the implementation of judicious soil and water management practices to sustain crop productivity.