title: A comparison of the rhizosphere-based method with DTPA, EDTA, CaCl2, and NaNO3 extraction methods for prediction of bioavailability of metals in soil to barley.
abstract: A rhizosphere-based method was compared with DTPA, EDTA, CaCl2, and NaNO3 extraction methods for the evaluation of bioavailability of heavy metals in soil to barley. The extractable amounts of Cr, Cu, Zn and Cd analyzed by the rhizosphere-based method correlated significantly with the metal content of barley roots. The extractable metals identified by DTPA, EDTA, CaCl2 and NaNO3 methods exhibited relatively poor or no correlation with the metal content of barley roots. The stepwise multiple regression equation of the rhizosphere-based method was the simplest one, as no soil properties needed to be entered, whereas the equations for the DTPA, EDTA, CaCl2 and NaNO3 extraction methods always require those variables. The most distinct feature of the rhizosphere-based method was that the proposed method was suitable for acidic, neutral and near alkaline soils. In contrast, the other extraction methods were restricted to soil types. In summary, the rhizosphere-based method is the most robust approach for evaluation of bioavailability of metals in soil to barley.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China. xiaoquan@mail.rcees.ac.cn
authors.forename: Mu-Hua
authors.initials: MH
authors.lastname: Feng
authors.forename: Xiao-Quan
authors.initials: XQ
authors.lastname: Shan
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Zhang
authors.forename: Bei
authors.initials: B
authors.lastname: Wen
mesh_terms: D001682:Biological Availability; D002122:Calcium Chloride; D002614:Chelating Agents; D004492:Edetic Acid; D004784:Environmental Monitoring / Q000379:methods; D001467:Hordeum / Q000737:chemistry*; D008670:Metals / Q000032:analysis*; D004369:Pentetic Acid; D018517:Plant Roots / Q000737:chemistry*; D012044:Regression Analysis; D012977:Sodium Nitrite; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D002614:Chelating Agents; D008670:Metals; D012989:Soil Pollutants; D004369:Pentetic Acid; D004492:Edetic Acid; D012977:Sodium Nitrite; D002122:Calcium Chloride