Soil fertility influence on ¹³⁷Cs and ⁹⁰Sr transfer to the crops

Belorussian Research Institute for Soil Science and Agrochemistry, Kazintsa Str. 62, 220108 Minsk, Belarus

Abstract

The radionuclide uptake by crops strongly depends on soil fertility and biological features of plants. The soil reaction, humus content, calcium, magnesium and potassium status are the most important soil properties, which determine radionuclide transfer to plants. The evaluation of separate soil property influence on the radionuclide uptake by plants is a complex task. It was found that ¹³⁷Cs and ⁹⁰Sr transfer to plants are reduced by a factor 1.5 to 3.0 as a result of the change of sodpodzolic soil reaction from acid (pH_KCI 4,5-5,0) to neutral range (pH_KCI 6,5-7,0), of humus content from 1.0 up to 3.5 % and of exchangeable potassium content from low (< 80 mg K₂O/kg of soil) up to high range (200-350 mg/kg). The lowest transferring of radionuclides to plants was observed at the optimal range of soil fertility parameters. On the basis of compilation and processing of experimental data the transfer factors of ¹³⁷Cs and ⁹⁰Sr from soil to crop had been differentiated according to soil fertility parameters for prediction of radionuclide accumulation in plant production. The soil fertility has to be improved in such a way that proposes the significant increase of crop yields with decreasing of the risk of people internal irradiation.