Delineation and characterization of salt-affected soils in Varanasi district of Uttar Pradesh

Abstract

Salt affected soils are primarily widespread over Uttar Pradesh especially in irrigated areas of the vast middle Indo-Gangetic alluvial plain of shallow water table depth and hot and dry moisture regions. Soil salinity and alkalinity are two of the main constraints present in these irrigated agricultural lands and the problem of salinity and alkalinity increases every year as a result of secondary salinisation and as a result of which the fertile productive land is gradually becoming unproductive. Varanasi district of Uttar Pradesh have been identified to the intensive area study site for this research work. Study area is a part of the vast alluvial expanse popularly known as Indo Gangetic plains. The study area lies in hot semi arid eco region 4.3, between geo-coordinates 25o 18’’ N and 83o 03’’ E covering 1, 535 sq km area a part of the vast Indo-Gangetic alluvial plain having sandy soil, which also coincides with low rainfall. The result indicated that the soil reaction is moderately to strongly alkaline. The organic carbon was reported to vary from 0.11 to 0.88%. Under saturation extract analysis, sodium ion was observed as dominant cation, followed by Calcium, Magnesium and Potassium and alkali soil having high pH are deficient in both soluble and exchangeable calcium.