Soil management practices to prevent soil acidification and base cation loss in tea plantation

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06308
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41030:Rural environmental engineering and planning-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Hirono Yuhei 国立研究開発法人農業・食品産業技術総合研究機構, 果樹茶業研究部門, グループ長補佐 (10391418)
• Co-Investigator(Kenkyū-buntansha): 中村 公人 京都大学, 農学研究科, 教授 (30293921)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 茶 / 酸性化 / 硝化 / 有機質肥料 / 窒素肥料

Outline of Final Research Achievements

The objective of this study was to clarify the balance of proton and base cations in tea gardens to develop appropriate soil management and to utilize organic materials in tea cultivation. We evaluated the accumulation and balance of fertilizer components in tea garden soil and the water quality in the surrounding water systems. From lysimeter experiments and investigations in tea gardens, it was revealed that the balance of Ca and Mg might be negative in general tea garden. Based on our surveys conducted in tea growing areas in two prefectures, it was confirmed that soil pH decreases with the planting years. This imbalance in fertilizer components also caused the acidification of surrounding water systems.

Free Research Field

土壌肥料

Academic Significance and Societal Importance of the Research Achievements

茶園への窒素施肥が引き起こす土壌酸性化について基礎的な知見を得た。現在の世界の窒素利用は地球システムの許容レベルを超える水準に達しており、水質汚染、温室効果ガス発生量の増大、土壌の酸性化等の問題が顕在化している。特に農業の生産性を考える場合、農地土壌の酸性化による生産性の低下は世界的に重要な問題であり、本研究成果を、適切な施肥管理に活用することで、茶園土壌の化学性を適正に保ち、茶の生産性の向上および持続的な茶生産へとつながることが期待される。