Reduction in bioavailability of arsenic in contaminated irrigated soil using zinc and organic manure

The experiments were conducted to reduce the bioavailability of arsenic with application of organic and inorganic materials from contaminated soils irrigated with arsenic contaminated water. the results showed that the amount of extractable arsenic increased with submergence and decreased with application of organic material. however,amount of such decrease altered with inorganic material i.e. zinc and decrease was greater with as5zn10 (0.17 to 0.0 mg/kg) where zinc was applied at the rate of 10 mg/kg. among the different organic materials,arsenic content in soil remarkably decreased with application of farmyard manure. the decrease in arsenic content was less than upper toxic limit of arsenic in soil i.e.10mg/kg for paddy soils. other manures also showed decrease in arsenic concentration but with desorption after half interval of treatment. best remediating agents used for arsenic retention was zinc sulphate> organic compost >farmyard manure.