Development of a model of absorption and metabolism of nutrients to support environmentally friendly hydroponics based on precision fertilizer management

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05849
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41040:Agricultural environmental engineering and agricultural information engineering-related
• Research Institution: Yamaguchi University
• Principal Investigator: Sago Yuki 山口大学, 大学院創成科学研究科, 准教授 (20648852)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 養液栽培 / 養分吸収速度 / 吸水速度 / 養分吸収モデル / 肥培管理

Outline of Final Research Achievements

Under closed hydroponics, the rate of nutrient absorption by the roots fluctuates with changes in weather conditions, and the fertilizer composition of the nutrient solution changes with time, resulting in reduced productivity. Therefore, a model-based estimation of nutrient absorption and a fertilizer management method that determines the amount of additional fertilizer based on this estimation may be effective for the long-term stabilization of the fertilizer composition of the nutrient solution. In this study, we established a practical evaluation method for water absorption rate under field conditions and a model of nutrient absorption by roots. Furthermore, it was demonstrated that a the new fertilizer management method stabilizes fertilizer composition over a long term to the same level as the method in which fertilizer concentration in the nutrient solution is measured and adjusted frequently.

Free Research Field

生物環境工学

Academic Significance and Societal Importance of the Research Achievements

環境負荷が少なく生産性の高い養液栽培を実現するためには，養分の培地―植物間における動態や植物体内での蓄積・利用を推計し，時々刻々と変化する環境に対応した最適な意思決定を支援する数理モデルを構築し，そのモデルに基づき精密肥培管理を実現する必要がある。本研究により，培地―植物間の養分動態を支配する吸水速度の現場での実用的な評価手法と根の養分吸収モデルを確立するとともに，構築した養分吸収モデルを用いることで，持続的かつ生産性の高い精密肥培管理法の確立の見通しが立った。