Fundamental principles of the behavior of 137Cs in the soil and its migration into agricultural crops.

In this article, we present the results of long-term laboratory and field investigations designed to characterize the dynamics of the various forms of compounds of the radionuclide in the soil in relation to its biological accessibility to plants. The variations in the extent of migration of 137Cs from the soil into the harvested parts of agricultural crops on the most typical soils, the contribution of the processes of fixation of the radionuclide to these variations, and the role of various properties of the soil in the migration of 137Cs into plants and the possible fluctuations in the migration of the radionuclide into plants caused by the interspecific and varietal characteristics of the plants are also discussed. The quantitative characteristics of the migration of 137Cs into the crops determined in vegetation, microfield experiments, and field experiments are compared and the possibilities of extrapolating the results of the experiments of the first two types to natural conditions are demonstrated.