Effects of potassium fertilization on cesium-133 absorption by persimmon trees

Abstract

In 2011, the Fukushima Daiichi Nuclear Power Station accident released radioactive materials, such as cesium (Cs), into the atmosphere and dropped onto agricultural land soil. Reducing radioactive Cs absorption from the soil is important for crop production. Therefore, persimmons were cultivated in pots with different amounts of potassium (K) fertilizer (+0 g, +20 g (standard level), and +40 g of K sulfate/pot), and the concentration of ¹³³Cs in leaves and fruits was investigated. Additionally, the effects of phlogopite (materials expected to enhance K availability and radioactive Cs fixation in the soil) were investigated. K fertilization increased the exchangeable K concentration in the soil, and as the investigation continued, a significant difference in the K concentration in the leaves was observed. From the beginning of the ¹³³Cs measurement, the ¹³³Cs concentration in the leaves and fruits was significantly higher in the treatment without K fertilization. When the exchangeable potassium concentration in the soil was approximately 200 mg K₂O kg⁻¹ or less, the ¹³³Cs concentration in the leaves tended to increase sharply. This suggests that controlling the Cs concentration in persimmon plants is possible by maintaining the exchangeable K concentration in the soil through K fertilization.

Keywords:

• Cs-133
• exchangeable potassium
• nuclear power plant accident
• persimmon
• soil

Acknowledgments

We would like to thank Dr. Ishikawa (Institute of Crop Science, NARO), Dr. Okazaki (Institute for Agro-Environmental Sciences, NARO), Dr. Takagi (Fukushima Institute for Research, Education and Innovation, Reconstruction Agency), and Dr. Wakabayashi (Office of the President, NARO) for their support in ICP-MS analysis. We also thank Ms. R. Hasegawa and Ms. K. Sugihara of the NARO Institute of Fruit Tree and Tea Science for technical assistance. The members of the Fukushima Technical Team at the NARO Tohoku Agricultural Research Center provided support for the installation of irrigation equipment.

Disclosure statement

The authors report there are no competing interests to declare.

Funding details

This study was partly conducted under the ‘Development of countermeasure technologies against radioactive materials for the resumption of farming projects’ funded by MAFF in Japan.

Additional information

Notes on contributors

Sachie Horii

Sachie Horii Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization Division of Fruit Tree Production Research, Fruit Tree Smart Production Group, Senior Scientist, Research on radioactive cesium in fruit trees.

Hiromichi Inoue

Hiromichi Inoue Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization Division of Fruit Tree Production Research, Fruit Tree Smart Production Group, Senior Principal Scientist, Research on soil fertilizer for fruit trees.

Shinnosuke Kusaba

Shinnosuke Kusaba Agriculture, Forestry and Fisheries Research Council, Ministry of Agriculture, Forestry and Fisheries, Research Managing Director, Technology development related to high-quality stable production and labor saving of deciduous fruit trees (Japanese pear, peach, etc.).