*JITHYA NAWODI WIJESINGHE¹, Jun Koarashi², Mariko Atarashi Andoh², Yoko Saito Kokubu³, Noriko Yamaguchi⁴, Takashi Sase⁵, Mamoru Hosono⁶, Yudzuru Inoue⁷, Yuki Mori¹, Syuntaro Hiradate¹ (1.Soil Science Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan, 2.Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki 319-1195, Japan, 3.Tono Geoscience Center, Japan Atomic Energy Agency,Gifu 509-5102, Japan, 4.National Agriculture and Food Research Organization, Institute for Agro-environmental Sciences, 3-1-3 Kan-nondai, Tsukuba, Ibaraki 305-8604, Japan, 5.Boreal Laboratory for Phytolith Research, Iwate 028-7302,Japan, 6.Tokyo Natural History Research Structure,Tokyo 162-0052, Japan, 7.Faculty of Applied Information Technology, Nagasaki Institute of Applied Science,Nagasaki 851-0193, Japan )

*Taiga Okumura¹, Noriko Yamaguchi², Terumi Dohi³, Kenso Fujiwara³, Kazuki Iijima³, Toshihiro Kogure¹ (1.The University of Tokyo, 2.National Agriculture and Food Research Organization, 3.Japan Atomic Energy Agency)