Rediscovering the value of small-scale wasabi fields - focusing on wasabi fields in Shizuoka City

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05662
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39070:Landscape science-related
• Research Institution: Tokai University
• Principal Investigator: Takeuchi Shinichi 東海大学, 海洋学部, 教授 (30268817)
• Co-Investigator(Kenkyū-buntansha): 田中 伸彦 東海大学, 観光学部, 教授 (70353761) ; 篠崎 圭太郎 南九州大学, 環境園芸学部, 都城事務部フィールドセンター課 主任 (30842306)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: わさび田 / 水温 / 微気象 / 観光 / 石積み / 水管理

Outline of Final Research Achievements

Water shortages in winter are noticeable in the wasabi fields located at upstream of the Abe River. The water temperature distribution in the two wasabi fields ranged from 10 to 18°C. At the high-altitude survey site, the number of days per year when the temperature fell below 8°C, the minimum temperature for wasabi growth, was 50 to 80 days. At the low-altitude survey site, the number of days was stable at 11 days. The temperature difference between the two altitudes affected by the wasabi irrigation water was reversed, making it difficult to apply the Bowen heat balance method to calculate evapotranspiration rate. Sap flow rate was active during the dry season in the cypress forest at the top of the wasabi fields, suggesting competition for water with the wasabi irrigation water. The tourist structure surrounding the wasabi fields was limited in terms of the concentration of accommodation facilities and the options as a destination.

Free Research Field

農業水利学

Academic Significance and Societal Importance of the Research Achievements

わさびの正常生育に最も重要な水温情報を長期間で複数地点において得た点、わさび田の微気象環境がモザイク状に成立していることを計測事実として得た点、冬季の低温期にわさび用水が田面表層10cmの気層を加温していることを示した点は、貴重な学術的成果である。さらに本研究はわさび田の多面的な機能として、セラピー効果や観光構造などに言及した点は社会的な意義を提示した内容となっている。わさび栽培者の認識に科学的な調査結果を加えて情報を発信することで、小規模わさび栽培の価値を広く認識してもらうために有用である。