Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden. I. County of Gavleborg.
In 1986, 15 farms in the Chernobyl-affected area of the county of Gavleborg were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0-5 cm) in 1986 and the crop products in 1986-1994 were analysed. The aim was to study the impact of site and soil characteristics on sensitivity of 137Cs transfer in a long-term perspective. The transfer was much higher to grass than to cereal grain. For both crop products, however, there was a considerable annual reduction. For grass, and especially in the fallout year 1986, the transfer depended on interception capacity of the stubble and grass sward, on soil fertility and K-fertilization as well as on dilution by crop growth. In the following years, the annual reduction in transfer to grass was reduced by a factor of 2 to 100. Both ploughing through the surface layer and the mixing of radiocaesium with soil contributed to a decreased transfer of radiocaesium to crops. Thick stubble and grass sward on the grassland sites was the main reason for a lag period of high persistent transfer. The annual reduction was less on organic than on mineral soils. Measures to decrease the transfer to crops are discussed in relation to a new concept to evaluate the long-term behaviour of 137Cs in agricultural environments.
Rosen
K
K
Department of Radioecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Eriksson
A
A
Haak
E
E
D000383:Agriculture; D002588:Cesium Radioisotopes / Q000032:analysis* / Q000493:pharmacokinetics; D002523:Edible Grain / Q000737:chemistry* / Q000378:metabolism; D006109:Poaceae / Q000737:chemistry* / Q000378:metabolism; D011210:Power Plants; D011847:Radioactive Fallout; D018788:Radioactive Hazard Release; D012987:Soil / Q000032:analysis; D012990:Soil Pollutants, Radioactive / Q000032:analysis* / Q000493:pharmacokinetics; D013548:Sweden; D014455:Ukraine
D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D012987:Soil; D012990:Soil Pollutants, Radioactive