In greenhouse and plant factory production, improper design of the ventilation system and increasing scales will lead to a stagnant airflow zone, which could inhibit plant growth and induce physiological disease, such as tipburn.
To increase the airflow within the plant canopy, simplify the equipment complexity, and improve operation convenience, a cultivation system was designed to provide a constant airflow within the plant canopy by integrating ventilation ducts with cultivation tanks. A three-dimensional computational fluid dynamics (ANSYS Fluent 2021R2) model was developed and validated through simulating the airflow distribution within the plant canopy under different intake air velocities. According to the simulated results, an intake air velocity of 10 m s−1 showed better airflow uniformity, and the proportion of the suitable zone reached the highest value of 83% at an intake air velocity of 20 m s−1. To validate the practical effectiveness of cultivation, a cultivation experiment was conducted. Five different canopy air velocities were set at 0 (CK), 0.35 (T1), 0.5 (T2), 0.65 (T3), and 0.8 (T4) m s−1, respectively. The results showed that the photosynthetic and transpiration rate, as well as the fresh and dry weights of lettuce plants (Lactuca sativa cv. 'Tiberius'), increased by 17.8%, 21.7%, 29.6%, and 29.9%, respectively, under treatment T4 compared to those under the control, while the canopy air temperature and relative humidity decreased by 1.3 °C and 3.2%, respectively.
The above results indicate that the newly designed cultivation system can be considered an effective system for improving lettuce plant growth and its canopy environment.
Zhang, Y.; Chen, C.; Fang, H.; Tong, Y. Improving Air Distribution Within Lettuce Plant Canopy by Employing Double-Channel Ventilation Cultivation System: Simulation and Experiment Study. Agronomy 2025, 15, 2326. https://doi.org/10.3390/agronomy15102326
Source: MDPI
