|
(38-06) New aspects of soil-to-plants transfer modeling. Goncharova, Nadezhda*,1, Albrecht, Achim2, Obolonkin, Vladimir1, Putyrskay, Vika1, Kalinkevich, Katia1, 1 International Sakharov Environmental University, Minsk, Belarus2 Swiss Federal Institute of Technology,Institute of Plant Sciences, Zurich, Switzerland ABSTRACT- Radioecological research in agroecosystems of Southern Belarus demonstrates a considerable variability among soil-to-plant transfer factors for 137Cs, regardless of the variability in soil types. The level of complexity and dynamics requires statistical approaches for modeling radiological doses caused by the consumption of crops produced in polluted zones. We propose multivariate analyses that consider aspects, which were mostly disregarded up to now, such as soil structure and plant physiology. Particularly soil structure and the resulting plant root distributions are highly different within arable soil profiles. Most of the presently used uptake models are based on uniform soil conditions, where single coefficients are used to describe the transfer of contaminants to the plant. Our model accounts for the spatial distribution of contaminants in soil profiles, conditioned by preferential flow, aggregate break-up and formation, plant root architecture. Furthermore, physiological mechanisms, which determine the dynamics and variability of soil-to-plant transfer, are considered. Processes such as bonding characteristics and "capacity" of radionuclide accumulation have been studied in hydroponic and soil culture systems. Results show that the cation-exchange capacity of plant tissues, for example, substantially determines the level of radionuclide accumulation. It is flexibly controlled and reflects delicately the functional state of the plant organisms. Key words: plant physiology, root uptake, agroecosystem, radionuclide |
