Iron Slime: An Amendment in Mitigating Arsenic Accumulation in Rice

Disposal of iron slime, the by-product of steel industry, is a matter of environmental and ecological concern. A greenhouse experiment was conducted to study the potentiality of iron slime as an amendment in mitigating arsenic (As) accumulation and yield reduction of rice. The experiment was conducted in factorial completely randomized design with three levels of arsenic spiking: 0, 5, and 10 mg kg(-1) and three doses of iron slime: 0, 10, and 20 g kg(-1) in three As status soils (< 7, 7-14, and > 14 mg As kg(-1) soil)(.) With the application of iron slime at 10 g kg(-1), the available As content in soil declined by 21.0, 14.4, and 12.1%, but increased the rice grain yield by 7.11, 5.58, and 5.16% over respective control in low, medium, and high As soil. The arsenic concentration in rice grain decreased to the tune of 38.6 to 23.8% with the application of iron slime at 10 g kg(-1) over their respective control in three As status soils. Translocation coefficients between different plant parts indicated that translocation of As within different plant parts was more a physiological trait of plant than the dose iron slime or As spiking, but their absolute concentration depended on the soil As level. Iron slime at 10 g kg(-1) (equivalent to 20 t ha(-1)) can be considered as an efficient amendment for mitigating the As concentration in rice grain besides increasing the yield in As-contaminated soils.