Assessment of countermeasure effects on ¹³⁷Cs accumulation from soil by farm crops after the accident at the Chernobyl NPP

¹ Russian Institute of Agricultural Radiology and Agroecology (RIARAE), Kievskoe Shosse, 109 km, Obninsk 249032, Russia
² Bryansk Center “Agrochemradiology”, Bryansk Reg., Sportivnaya Str. 1., Michurinsky 241524, Russia

Abstract

Using the south-western districts in the Bryansk region affected by the Chernobyl accident as an example, the dynamics has been estimated of ¹³⁷Cs transfer factors to plants and effects of countermeasures on the accumulation of this radionuclide by farm products. A significant decline with time in TF ¹³⁷Cs to plants is shown. Over the 20 years after the radioactive fallout this decline varies from 7 to 85 times for different plants, being maximum in the early years. The ¹³⁷Cs accumulation by plants is greatly influenced by the soil properties. Thus, the maximum transfer of this radionuclide to plants is reported on peaty soils, somewhat lower on sandy soils and minimum on sandy loam soil. A detailed comparative analysis of data on TF ¹³⁷Cs to plants grown on sandy and sandy loam soils has shown that on the former transfer is higher and varies between 1.2–4.5 times for different crops. An important role of mineral fertilizing and liming of soil has been proved in reducing ¹³⁷Cs accumulation in plants. On agricultural lands that saw the increased rates of mineral fertilizing, a significant (by an average factor of 3–7) reduction in TF ¹³⁷Cs was reported compared to the plots with no countermeasures.