The influence of soil parameters on 137Cs+-uptake by plants from long-term fallout on forest clearings and grassland.

An attempt was made to show if and to what extent the 137Cs transfer from soil to plants (grass) in forest clearings and grassland is related closely enough to different soil parameters to make it worthwhile to develop mathematical models for the prediction of transfer coefficients for certain plants and sites based solely on soil parameters. For this reason 62 soil samples from 0- to 5-cm in depth as well as from 5- to 10-cm in depth were measured for worldwide 137Cs fallout and analyzed for exchangeable potassium content, total potassium content, clay fraction, potential exchange capacity, pH value and carbon content. For both ecosystems, large variations of the transfer coefficients were observed: between 0.01 and 0.1 for grassland and 0.05 and 6 for forest clearings . Correlations, such as has been found between soil parameters, specific activities of the plants and transfer coefficients can in principle be integrated into different calculations for the estimation of radiation burden.