Development of crop growth model coupled with soil water and solute dynamics model accounting for topography and light environment

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H03097
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 41030:Rural environmental engineering and planning-related
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Saito Hirotaka 東京農工大学, (連合)農学研究科(研究院), 教授 (70447514)
• Co-Investigator(Kenkyū-buntansha): 辰己 賢一 東京農工大学, (連合)農学研究科(研究院), 准教授 (40505781) ; 山下 恵 東京農工大学, (連合)農学研究科(研究院), 准教授 (70523596) ; 小島 悠揮 岐阜大学, 工学部, 准教授 (70767475)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 土壌物質動態モデル / 作物モデル / 数値解析

Outline of Final Research Achievements

The objective of this study was to construct a sophisticated integrated dynamic crop growth modelling tool by coupling the soil water and solute transport model, HYDRUS, and the canopy photosynthesis model, iRGM, which can take into account climatic conditions, surface conditions, and soil, water, and fertilizer management. The model was coupled through root water and nitrogen uptake, and the potential transpiration rate was obtained from the LAI computed by iRGM, and the actual transpiration rate was determined from soil moisture conditions. Nitrogen dynamics in the soil, including mineralization, was also computed simultaneously, and nitrogen was uptaken in accordance with water uptake. The growth process of rice plants was calculated using this coupled model and compared with observed data. The coupled model was able to calculate the growth process of the crop while precisely calculating soil moisture and nitrogen dynamics, and reproduced the measured data well.

Free Research Field

地域環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した統合動的作物成長モデルでは，土中の物質移動と作物の成長過程を同時にかつ精緻に計算できるモデルとなっており，たとえば乾燥地での最適な水・肥料の管理を最適化するためのサポートツールとして使えるとともに，地球温暖化に伴う長期的な気候変動が農作物の成長に与える影響の評価に利用することができる．また本研究により開発したモデルを仮想空間上で圃場を再現し，農業の栽培支援を行う農業デジタルツイン等への応用が今後は期待される．