Arsenic mitigation in soil-plant system through zinc application in West Bengal soils

The study area of the experiment was selected on the basis of a preliminary field survey and laboratory detection of accumulation, accompanied by biomagnification, of arsenic in the water-soil-plant continuum. A laboratory incubation study was conducted with soil samples from the selected areas of West Bengal with arsenic-contaminated groundwater, and from a low arsenic zone. These soils were treated with different concentrations of zinc and arsenic and incubated for 10 and 25 days. The findings from the incubation study indicate the decrement of arsenic release in the soil solution of the given soils on application of zinc, which tends to bind arsenic electrostatically in the soil matrix, thereby helping to mitigate the toxicity of arsenic to some extent in the soil-plant system. The arsenic-zinc interactions were further revalidated in the arsenic-affected fields where a similar type of moderating effect (as in the incubation study) was observed in rice-rice cropping sequence. Arsenic-zinc interactions were critically analyzed through a number of accumulation, translocation, and mobility parameters, considering soil to plant uptake in different plant parts.