Evaluation of 137Cs soil-to-plant transfer: Natural and model experiments

Soil and meadow grass were sampled in the whole territory of Lithuania in 1992–2000. For the laboratory experiment, spring wheat Triticum aestivum L. “Nandu” was used because its root system type is similar to that of perennial meadow grass. The 137 Cs soil-to-plant transfer factor of spring wheat was determined and the results were compared with the predicted values using a compartment model of soil-to-plant transfer and with the results of the field experiment. The results of comparing the measured and calculated transfer factor using the model show rather good coincidence, however, the calculated values were overestimated. The reason for overestimation can be that the uptake rate is not influenced only by the soil-to-plant transfer. The results of the model experiment (from 0.005 m 2 ·kg −1 to 0.053 m 2 ·kg −1 ) are close to those of the field measurements for grass (from 0.013 m 2 ·kg −1 in 1992–1995 to 0.10 m 2 ·kg −1 in 1999–2000).