Effect of Phytoremediation on Chemical Characteristics of a Calcareous Saline-sodic Soil

A calcareous saline-sodic soil (pHs= 8.26, ECe = 9.07 dS m‾1, SAR = 37.90, CaCO3 = 8.58%, texture = sandy clay loam) packed in concrete lysimeters was tested for phytoremediation. The treatments were: No-Sesbania (SO), Sesbania-harvested (SH) and Sesbania-incorporated (SI) before flowering. Rice-wheat crop rotation was followed after Sesbania. Each crop was irrigated with high RSC water (3.1 mmolc L‾1) according to its water requirement and 20% additional water was allowed to infiltrate to carry down salts. Thirteen leachates were collected during the course of study. At termination of the experiment, pHs of soil increased while ECe and SAR decreased with all the treatments, change was more at 15-30 cm soil depth compared to that of 0-15 cm. The ECe: SAR ratio decreased with all the treatments showing an increase in Na+ hazard. It suggests that the use of water having high RSC could not be useful for reclamation without the use of a chemical amendment (Ca2+ source) and phytoremediation seems of little usefulness to improve soil under such conditions.