Journal of the Indian Society of Soil Science

Leaching requirement of three salt-affected soils belonging to Typic Chromustert, Vertic Ustochrept and Patalithic Ustochrept, and occurring in the Bhal region of Gujarat was studied in PVC columns of 0.35 m length and 0.108 m internal diameter. Air-dried soils, ground and passed through a 2 mm sieve, were packed to a bulk density of 1.5±0.2 Mg m⁻³ in the PVC columns, and different amounts of water were passed through them. Leaching with 2.3 pore volumes of water removed 94 per cent of total salts and brought down ECe below 4 dS mol⁻¹ in 0 to 30 cm layer of the Vertic Ustochrept. For bringing down ECe below 4 dS m⁻¹ in 0 to 30 cm layer of the Typic Chromustert, leaching with 2.8 pore volumes of water was required. The leaching treatment removed 97 per cent of total salt from the soil layer. Leaching with 2.6 pore volumes of water tried in Paralithic Ustochrept brought down ECe below 4 dS m⁻¹ in the 0 to 25 cm layer only by removing 97 per cent of total salt from there. Following relationships between EC/ECo (ECo and EC are electrical conductivity of saturation extracts of the soils before and after leaching,respectively) and Dw/Ds (Dw and Ds are the depth of water and soil, respectively) were established for the soils as EC/ECo=O.1045 (Dw/Ds)^−1.7096, r = -0.8486 for Typic Chromustert; EC/ECo=0.1450 (Dw/Ds)^−1.4551, r = -0.9658 for Vertic Ustochrept; and EC/ECo = 0.113 (Dw/Ds)^−1.5496, r = -0.9339 for Paralithic Ustochrept. These relationships suggest that to accomplish 80 per cent reduction in salinity, each cm of Typic Chromustert, Vertic Ustochrept and Paralithic Ustochrept should be leached with 0.64, 0.80 and 0.69 cm water, respectively.