Differential response of soil texture for leaching of salts receiving different pore volumes of water in saline-sodic soil column.

This study examined the leaching requirement of three saline-sodic soils in polyvinyl chloride (PVC) columns of 50 cm long and 11 cm internal diameter. Air-dried soils were packed in PVC lysimeters receiving different pore volume (PV) of water (EC 0.89 dS m/sup -1/, SAR 1.55, RSC 1.02 mmolc L/sup -1). Leaching with 2.5 PV of water removed 94 % of soluble salts and decreased EC/sub e/from 33.9 to 5.9 dS m/sup -1/ in 0-25 cm layer of sandy clay loam soil. For lowering EC/sub e/ to < 4 dS m/sup -1/ in loamy sand up to 0-25 cm soil layer, 2.0 PV water removed 67 % soluble salts. In silty clay loam soil, 2.5 PV water lowered EC/sub e/ to < 4 dS m/sup -1/only up to 0-10 cm depth with 83 % removal of salts. Relationships between EC/EC 0 and D w/Ds established were for the soils as EC/EC/sub 0/ = 0.329 (D w/D/sub S/)/sup -2.12/ with r= 0.87 for loamy sand; EC/EC/sub 0/ = 0.16sub -0.60/ with r=0.89 for silty clay loam and EC/EC/sub 0/sup = 0.06/ (Dw/D/sub s/)/sup 0.78/ with r=0.98 for sandy clay loam soil. These relationships leads to conclude that reduction in salinity of loamy sand, silty clay loam and sandy clay loam soil was 67, 83 and 94 % when leached with 1.88, 2.72 and 2.67 cm of water, respectively. (author)