tThis study investigated the effectiveness of 6 different types of naturally occurring manganese, aluminumand iron oxides for stabilization of As and Sb in a calcareous soil spiked with 50 mg kg−1of As or Sb andtwo dosages of treatments (2% and 5%). The resulting contaminated soils were subjected to a series ofchemical extraction studies including sequential extraction, single step extraction with DTPA and Sim-plified Bioaccessibility Extraction Test (SBET) for estimation of bioaccessible fraction of As and Sb in soiland a greenhouse experiment using barley as the test crop. The results showed that Fe-associated andcarbonate-bound fraction of As and Sb were predominant fractions. However, the amounts of labile frac-tions were higher in As contaminated soils, whereas the percentage of Sb associated with crystallineFe-oxide and residual fractions were higher. The results revealed that application of natural metal oxidesreduced DTPA and SBET extractable amounts and plant uptake of As and Sb. After application of amend-ments, the exchangeable fraction of As decreased dramatically by up to 82% while Sb exchangeablefraction decreased by up to 60% depending upon the additive. The results of chemical extractions andplant uptake confirmed that Sb had lower bioavailability, compared with As.

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