Relationships among 137Cs, 133Cs, and K in plant uptake observed in Japanese agricultural fields

Plant uptake of radiocesium ( 137 Cs) was investigated in consideration of the relationships with naturally existing 133 Cs and potassium (K). We first determined plant-unavailable fraction of 137 Cs in soil by batch sorption and sequential extraction methods with a radiotracer. Then, using the data obtained from the batch sorption and extraction methods, we clarified the relationships of plant-available and plant-unavailable fractions between 137 Cs, 133 Cs, and K in soil. Additionally, 137 Cs concentrations in crop were estimated using 137 Cs in soil and several factors, i.e. fixation ratio of 137 Cs in soil, cation exchange capacity, and K concentration in crop. The results implied that the fixation ratio of 137 Cs in soil was a very important key to understanding 137 Cs plant uptake.