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Abstract : |
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 (T1), Sesbania-harvested (T2) and Sesbania-incorporated (T3) 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 % extra water was allowed to infiltrate each time. Three leachate were collected during Sesbania, five during rice and four during wheat crop. One leachate was collected at pre-planting irrigation (Rouni) of rice. It was observed that the treatment from where Sesbania was harvested (T2) caused more salts leaching as compared to other treatments. Net salt removal was observed only during rice crop while during rest of the crops there was salt deposition in soil. Net CO32‾ removal increased while that of HCO3‾ decreased throughout the study period showing an increase in pH of soil solution phase. Similarly Ca2+ + Mg2+ removal remained less while that of Na+ more but similar with all the treatments than that of added through irrigation water indicating ineffectiveness of Sesbania either in the form of harvest or incorporate into the soil. It is opined that salts/ionic removal is not sufficient enough to coup with the amelioration of calcareous saline sodic soils. , A calcareous saline-sodic soil (pHs = 8.26, ECe = 9.07 dS mأƒآ¢أ‚€أ‚آ¾1, SAR = 37.90, CaCO3 = 8.58 %, texture = sandy clay loam) packed in concrete lysimeters was tested for Phytoremediation. The treatments were: No-Sesbania (T1), Sesbania-harvested (T2) and Sesbania-incorporated (T3) before flowering. Rice-wheat crop rotation was followed after Sesbania. Each crop was irrigated with high RSC water (3.1 mmolc Lأƒآ¢أ‚€أ‚آ¾1) according to its water requirement and 20 % extra water was allowed to infiltrate each time. Three leachate were collected during Sesbania, five during rice and four during wheat crop. One leachate was collected at pre-planting irrigation (Rouni) of rice. It was observed that the treatment from where Sesbania was harvested (T2) caused more salts leaching as compared to other treatments. Net salt removal was observed only during rice crop while during rest of the crops there was salt deposition in soil. Net CO32أƒآ¢أ‚€أ‚آ¾ removal increased while that of HCO3أƒآ¢أ‚€أ‚آ¾ decreased throughout the study period showing an increase in pH of soil solution phase. Similarly Ca2+ + Mg2+ removal remained less while that of Na+ more but similar with all the treatments than that of added through irrigation water indicating ineffectiveness of Sesbania either in the form of harvest or incorporate into the soil. It is opined that salts/ionic removal is not sufficient enough to coup with the amelioration of calcareous saline sodic soils., |
