Elucidating influence of a countermeasure against radiocesium uptake on water quality in watersheds

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14561
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Nishikiori Tatsuhiro 国立研究開発法人農業・食品産業技術総合研究機構, 東北農業研究センター, 主任研究員 (10636137)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 地下水質 / 河川水質 / 農地排水 / 塩化物イオン / 放射性セシウム対策

Outline of Final Research Achievements

Countermeasures have been conducted to control radiocesium uptake by crops since the accident at the Fukushima Daiichi Nuclear Power Plant,. A highly effective countermeasure is to increase the concentration of exchangeable potassium in soil. Although potassium chloride has been used as the main source material, chloride ion, for which a water quality standard for tap water is set in Japan, have possibly been discharged from farmlands into groundwater and rivers. In this study, we investigated the concentration of chloride ion in groundwater and river water in the areas where the countermeasure had been implemented in Fukushima Prefecture. We have found that there was no significant increase in the concentration and that this countermeasure has had a low impact on the water quality in the watersheds.

Free Research Field

水質学

Academic Significance and Societal Importance of the Research Achievements

福島第一原子力発電所事故は除染や耕作規制など農地環境に劇的な変化を与えました。放射性セシウムの吸収抑制対策であるカリウム増加施肥もその一つです。様々な人間活動が関連する環境にどのように影響するのか良い面も悪い面も含めて評価していくことは、後世へ残す教訓として重要です。カリウムによる対策が周辺水系の水質に顕著な影響を及ぼしていないという結果は、農業関係者や地下水を飲用水源として利用している住民の安心に繋がるでしょう。