Behaviour of Native Silicon and Phosphorus in Soil following Application of Sodic Water

A laboratory column experiment was conducted to study the effect of sodic waters on behaviour of native Si and P during reclamation of sodic soils. Three soils varying in pH i.e. reclaimed (pH 8.4), partially reclaimed (pH 9.2) and unreclaimed sodic soil (pH 10.2), were leached with 2, 4 and 8 pore volumes of sodic waters of 2.5, 5.0 and 10.0 me L⁻¹ RSC under constant water head. Silicon and P concentrations in the leachates were measured periodically. In high pH soil, infiltration rate was less and it took almost 10 times more time to pass the same volume of leachate as compared to that in low pH soils. Silicon losses increased significantly with increase in RSC of applied water irrespective of the initial pH of the soil, the extent of loss varied with the initial pH and silica content of the soil. Maximum loss of Si as well as of P occurred in unreclaimed sodic soil.