Effect of Interactions of Arsenic, Organic Manures and Sulphur on Arsenic Availability in Some Selected Soils of West Bengal

A laboratory incubation study was conducted to study the availability of arsenic (As) in some soils of West Bengal having As-contaminated groundwater, and also from an As-free zone. These soils were treated with sulphur (S), As and well-decomposed organic manures namely, compost and oilcakes. Results showed that application of compost in the As affected soils reduced the As extractability to the tune 38–39% while that of the same content has been reduced with lower magnitude (19 to 37%) with the application of oilcake. However, application of S coupled with or without manure increased As extractability. Application of manures coupled with the released As decreased the As concentration in soil solution. The increased extractability of As by S might be attributed to the competition of S with As for the same surface of the soil matrices, thereby moderating the toxicity of As in the soil-plant system. The interactions between As and S as well as As and compost were further revalidated in the fields growing mustard, where 2.17 and 11.2% reduction in As uptake by mustard grain was observed with a concomitant increase in yield by 5.88 and 4.58%, respectively with the application of highest doses of manure and S.