日本地球惑星科学連合2022年大会

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[J] 口頭発表

セッション記号 M (領域外・複数領域) » M-TT 計測技術・研究手法

[M-TT46] Introducing metaverse to agriculture. Are we ready?

2022年5月26日(木) 10:45 〜 12:15 202 (幕張メッセ国際会議場)

コンビーナ:二宮 正士(国立大学法人東京大学大学院農学生命科学研究科)、コンビーナ:高橋 幸弘(北海道大学・大学院理学院・宇宙理学専攻)、座長:成瀬 延康(滋賀医科大学 医学部医学科)

11:15 〜 11:30

[MTT46-03] Numerical simulations of photosynthesis for 3-D soybean canopy based on Farquhar model

*友部 遼1、田中 佑2 (1.東京工業大学 環境・社会理工学院、2.京都大学 大学院農学研究科)

キーワード:Farquhar モデル、3次元数値シミュレーション、ダイズ

It is necessary to design crop varieties that are adapted to an environmental condition prior to physically access there, in order for humans to live on multiple planets as well as on this planet. The rates of carbon assimilation of a crop canopy are the primary factor that determines whether or not the canopy can be grown in a given environment.

We have developed a virtual experimental field with a rule-based 3D modeller of crop canopies and a virtual 3D light environment to design well-adapted crops to a given environmental condition. The proposed model uses the well-known Farquhar model and its empirical parameters for the calculation of photosynthesis. For simplicity, only direct radiation was considered.

The following simulations were conducted in order to identify optimal leaf and petiole phenotypes under a typical light environment. A rectangular plot with 70 cm row width and 15 cm plant spacing was created under the following conditions: light intensity of 1000 μmol/s/m^2, solar altitude of 90°, and atmospheric CO2 concentration of 380 ppm.

As a result, the larger the leaf blade angle and the smaller the petiole angle, the greater the amount of the carbon assimilation under the same Leaf Area Index of (LAI = 3.0). Canopies with the most optimal phenotype of petiole angle, petiole length, leaf shape, and leaf length had about four times larger carbon assimilation ratio than the most unsuitable ones, even though they had exactly the same LAI. It is known that the response of the carbon assimilation rate to the rate of increase in LAI tends to slow down when LAI>3.0. However, the photosynthetic rate continued to increase even when the LAI increased above 3.0 in cases that canopies have upright leaves and horizontally arranged petioles. Among the results, the effect of petiole angle is suggested for the first time, although it is consistent with the empirical finding that upright leaves are advantageous.

Furthermore, it is suggested that the computational cost is significant to find the optimal stem structure and spacing conditions based on the present scheme, which necessitates development of faster photosynthesis simulation schemes. Also, it is necessary to take into account diffuse radiation, considering natural light environments.