Potassium applications reduced cesium uptake and altered strontium translocation in soybean plants

ABSTRACT

After the Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Plant accident in 2011, radioactive cesium (RCs) was released in greater concentrations than radioactive strontium (RSr) in the surrounding environment. Most of the countermeasures were developed to mitigate the RCs transfer from the soil to plants. However, to avoid what has happened after the Chernobyl and Mayak accidents, preventing the transfer of RSr from soil to plants should be a priority. Although the application of potassium (K) fertilizers is the most effective method for preventing agricultural crops from absorbing RCs in contaminated fields, this implementation increases the cost and labor requirements. Considering the preparedness for nuclear accidents, it remains unclear how this countermeasure will be affected if RCs and RSr are released simultaneously. We aimed to explore the effect of K applications on cesium (Cs) and strontium (Sr) uptake and their interaction with and correlation to other elements in the soybean plants and soil. The field experiments were conducted in Fukushima Prefecture, Japan, using different K applications (i.e., no, normal, and high K applications). The dry weight and mineral concentrations of K, Cs, Sr, calcium (Ca), magnesium (Mg), and nitrogen (N) concentration in plants and exchangeable K (ExK), exchangeable Cs (ExCs), exchangeable Sr (ExSr), exchangeable Ca (ExCa), exchangeable Mg (ExMg), NH₄+ (ammonium), and NO₃- (nitrate) concentrations in the soils were evaluated. This study revealed that K application reduced Cs, Ca, and Mg uptake but did not affect the ExSr, ExCa, and ExMg concentrations in the soil and did not change the uptake of Sr. On the other hand, K concentration of the plant especially at later growth stage, which indicates re-translocation of Sr was negatively regulated by K concentration.

KEYWORDS:

• Soybean
• cesium
• strontium
• countermeasure
• potassium

Acknowledgments

We are grateful to Mr. Shigeto Fujimura for management of the fields, Ms. Tomoko Saito, Ms. Yuko Abe, Ms. Michie Mimori, and Ms. Yurie Yoshida for supporting sample preparation for the analysis (the Agricultural Radiation Research Center, NARO Tohoku Agricultural Research Center). We would like to thank Ms. Hisae Fujimoto (Graduate School of Agriculture, Hokkaido University) and Mr. Satoshi Asaeda (Graduate School of Agriculture, Hokkaido University and Hama Agricultural Regeneration Research Center, Fukushima Agricultural Technology Center) for helping us with the analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00380768.2023.2166776.

Additional information

Funding

This study was supported by a scheme to Revitalize Agriculture, Forestry and Fisheries in the Disaster area of Fukushima Prefecture through Deploying Highly Advanced Technology (MAFF) and the Coordinated Research Project of IAEA (CRP D15019, Remediation of Radioactive Contaminated Agricultural Land).