Systematic Soil Survey to Identify Potential Sodicity Areas in Parts of Tawa Command, Madhya Pradesh

Detailed soil survey was carried out in parts of Tawa Command area which lies in the flood plain of Narmada and Tawa rivers. The soils belong to Vertisols and associated shrinkswell soils. Properties of two soil series, viz. Rohana-1 (Rb1) and Rohana-2 (Rb2) are described; the former being cultivated and the latter uncultivated. Clay content of the two soils is comparable, through RbI soils have higher clay content. Infiltration rate is lower in RbI than in Rh2 soils. There is an increasing trend of Na, Mg/Ca ratio and ESP values with depth for Rb1, but usually insignificant for Rb2. Well water (W1) has higher values of pH, Na, Mg/Ca ratio, residual sodium carbonate (RSC) and SAR than canal irrigation water. It is thus envisaged that use of such ground water with lower EC and higher Na values (which is potentially sodic), may deteriorate the soil structure and decrease the infiltration rate by causing dispersion of clays. Moreover, systematic soil survey helped to identifY and show that for shrink-swell deep black soils, irrigation even with slightly poor quality water may be hazardous for soil environment in the Tawa Command region.