Comparison between fractionation and bioavailability of trace elements in rhizosphere and bulk soils

摘要: Rhizosphere is a microbiosphere and has quite different chemical, physical biological properties from bulk soils. A greenhouse experiment was performed to compare the difference of fractionation bioavailability trace elements Cr, Ni, Zn, Cu, Pb Cd between rhizosphere soil soil. In meantime, influence air-drying on also investigated by using wet sample as control. Soils in homemade rhizobox were divided into four zones: rhizosphere, near zones, which designated S-1, S-2, S-3 S-4. Elemental speciations fractionated water soluble, exchangeable carbonate bound (B1), Fe-Mn oxide (B2), organic sulfide (B3) sequential extraction procedure. Speciation differences observed for soils, air-dried soils well. The concentrations all six heavy metals fraction B1 followed order S-2 > S-1 S-4 B2, S3 approximate S-1. For B3, while increased elemental concentration fractions B2 20-50% decreased B3 about 20-100%. Correlation analysis indicated that correlation coefficient plants better than either or nonrhizosphere Therefore, application should be recommended future study speciation bioavailability. (C) 2002 Elsevier Science Ltd. All rights reserved.