Plant and Soil

, Volume 211, Issue 1, pp 131–138

Root uptake and distribution of radiocaesium from contaminated soils and the enhancement of Cs adsorption in the rhizosphere

  • A. Guivarch
  • P. Hinsinger
  • S. Staunton
Article

DOI: 10.1023/A:1004465302449

Cite this article as:
Guivarch, A., Hinsinger, P. & Staunton, S. Plant and Soil (1999) 211: 131. doi:10.1023/A:1004465302449

Abstract

Uptake by roots from contaminated soil is one of the key steps in the entry of radiocaesium into the food chain. We have measured the uptake by roots of radiocaesium and its transfer to shoots of a heathland grass, sheep fescue (Festuca ovina L.) from two contrasting agricultural soils, a sandy podzol and a clayey calcareous soil. A culture device which keeps the roots separate from the soil was used thus allowing rhizosphere soil to be obtained easily and enhancing the effect of root action. Biomass production and 137Cs in shoots and roots were recorded. Cs adsorption was studied on both the initial, nonrhizosphere soil and on rhizosphere soil in dilute soil suspension. Cs desorption was measured by resuspending subsamples of contaminated soil in solutions containing various concentrations of stable Cs. The proportion of Cs fixed, i.e. not readily desorbable, was calculated by comparison of the adsorption and desorption isotherms. Uptake by roots varied considerably between soils and did not appear to be diffusion limited. Root-to-shoot transfer did not differ for the two soils studied. Root action considerably enhanced Cs adsorption on the soils, particularly the in sandy podzol with a low Cs affinity. The value of Kd was increased by up to an order of magnitude. A large proportion of adsorbed Cs was found to be fixed, the Kd was up to seven times greater on desorption than adsorption, indicating that up to 80% of adsorbed Cs was not readily exchangeable. Root action had little effect on the fixed fraction.

adsorption Festuca ovina L. radiocaesium rhizosphere root uptake soil 

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • A. Guivarch
    • 1
  • P. Hinsinger
    • 1
  • S. Staunton
    • 1
  1. 1.Unité de Science du SolINRAMontpellier CedexFrance

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