Transfer Factors of Sr-90 from Corn Grown on Four Soils Typical of Bulgaria

Transfer factors of technogenic radionuclide strontium-90 were studied in vegetationexperiment in four soils typical of Bulgaria. The four soil types were – Alluvial meadow(Fluvisol), Smolnitsa (Pellic Vertisol), Cinnamon forest soil (Chromic Luvisol) and Leachedchernozem (Haplic Chernozem), respectively. The agricultural crop under study was corn.It was found the content of strontium-90 was the highest in the leaves of the plant,less in the stems and the least in the generative organs of the crop – the grain. The data of thetransfer factors obtained for the four soils typical of Bulgaria were comparable with theresults cited by other authors for soils specific for temperate environments.Higher uptake of strontium-90 was observed in corn grown on Chromic Luvisol andFluvisol compared to Pellic Vertisol and Haplic Chernozem, most probably due to the lowercontent of physical clay, exchangeable calcium and magnesium and humus in the first two soiltypes.