Microbes influence the fractionation of arsenic in paddy soils with different fertilization regimes

Abstract

Sequential extraction procedures were used to investigate the influence of the microbes on the distribution of arsenic in a Chinese paddy soil under different long-term fertilization treatments. The paddy soil with four long-term fertilization treatments (CK, M, NPK and NPK + M) and three levels of arsenate addition (0, 50, 100 mg As kg- 1 dry soil), were selected to construct microcosms for laboratory incubation. After the incubation, soil samples were sequentially extracted to determine As in various fractions, i.e. water soluble (F0), exchangeable (F1), bound to carbonates (F2), bound to Fe and Mn oxides (F3), bound to organic matter and sulfides (F4), and residual (F5, mineral matrix). R..