Elsevier Editorial System(tm) for Journal of Environmental Radioactivity Manuscript Draft

Manuscript Number: JENVRAD-D-08-00104R1 Title: Modeling of 137Cs migration in soils using an 80-year soil archive. Role of fertilizers and agricultural amendments Article Type: Research Paper Keywords: radioactivity, Chernobyl, pollution, radiocaesium Corresponding Author: Dr Fabrice Monna, Corresponding Author's Institution: Université de Bourgogne First Author: Fabrice Monna Order of Authors: Fabrice Monna; Fokert van Oort; Philippe Hubert; Janusz Dominik; Jérome Bolte; Jean Luc Loizeau; Jérome Labanowski; Jérémi Lamri; Christophe Petit; Gaël Le Roux; Carmela Chateau Abstract: An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters:
, a proportional factor allowing the historical atmospheric 137Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudounknown is however necessary to run the model: the shape of historical 137Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of
1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0-25 cm horizon, the residence half-time is found to be
18 years (including both migration and radioactive decay). Migration rate constants are also