Uptake of radionuclides by spring wheat and barley from cultivated soils supplemented by contaminated sewage sludge

Authors

• Marketta Puhakainen Finnish Centre for Radiation and Nuclear Safety, Box 268, SF-00101 Helsinki, Finland
• Toivo Yläranta Agricultural Research Centre of Finland, Institute of Environmental Research, SF-31600 Jokioinen, Finland

DOI: https://doi.org/10.23986/afsci.72427

Abstract

After the accident at the Chernobyl nuclear power station in April 1986, large amounts of fallout radionuclides originating from Chernobyl were measured in sewage sludge in Finland. Field experiments were performed to evaluate the amount of activity of fallout nuclides transferred from soil to spring wheat and barley grown in fields supplemented by contaminated sewage sludge and further to calculate the soil-grain transfer factors. The experiments were conducted in southern Finland on clay, clay loam and sandy loam soil. The digested sludge was spread on fields, at a ratio of 22 tons of dry matter per hectare. The sludge formed in 1986 was spread in spring 1987 on ploughed fields before the preparation of the seedbed, or in autumn 1987 prior to ploughing. The different plots were fertilized with NPK fertilizer so that the amount of available nutrients was about equal in all treatments. Application of sludge increased the concentration of 137Cs in grain 2-12 times as compared with crops grown in plots without sewage sludge addition. The transfer factor of 137Cs from soil to plant defined as Bq ha-1 in plant (grain and straw) per Bq ha-1 in soil (and sludge) varied in the first experimental years (1987 and 1988) from 20 x 10-6 to 150 x 10-6 and in the second experimental years (1988 and 1989) from 6 x 10-6 to 50 x 10-6 for sludge treated soil and from 10 x 10-6 to 60 x 10-6 and from 8 x 10-6 to 50 x 10-6 for soil without sludge addition, respectively.