Relationship between radiocesium absorbed by paddy rice and trapped by zinc-substituted Prussian blue sheet buried in soil

ABSTRACTRice absorbs radiocesium dissolved in soil solution. However, quantitative determination of dissolved radiocesium is difficult because large volume of water should be collected from paddy soil. We investigated whether a sheet capable of effectively trapping cesium (zinc-substituted Prussian blue (ZnPB) sheet) can be used to evaluate the level of dissolved 137Cs to be absorbed by rice. A new device equipped with ZnPB sheet was invented to trap only radiocesium dissolved in soil solution, which is passed through a membrane filter covering the ZnPB sheet. A rice pot-culture experiment using three paddy soils with different 137Cs concentrations and physico-chemical properties collected from Fukushima Prefecture was conducted under different fertilization or rice-planting treatments. The results showed that 137Cs concentration in brown rice was positively correlated with the 137Cs concentration in soil solution with a contribution ratio of regression R2 of 0.91 and a p value less than 0.01, and also wi...