Liu Anhua, Henke Michael, Li Yiming, Zhang Yue, Xu Demin, Liu Xingan, Li Tianlai
College of Horticulture, Shenyang Agricultural University, Shenyang, China.
Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China.
Front Plant Sci. 2022 Aug 23;13:966596. doi: 10.3389/fpls.2022.966596. eCollection 2022.
The non-uniform growth and development of crops within Chinese Solar Greenhouses (CSG) is directly related to the micro-light climate within canopy. In practice, reflective films are used to improve micro-light climate within plant canopy by homogenizing light distribution and so increasing total plant light interception. However, as to our knowledge, the contributions to light distribution within canopy have not been investigated for passive reflector like reflective films. Field experiments dealing with light conditions and growth behavior over time, are complicated to carry out, time-consuming and hard to control, while however, accurate measurements of how reflective films influence the micro-light climate of canopy are an essential step to improve the growth conditions for any crop. Here, we propose a supplementary light strategy using reflective films to improve light distribution within plant canopy. Based on the example of CSG, a 3D greenhouse model including a detailed 3D tomato canopy structure was constructed to simulate the influence of supplementary reflective films to improve micro-light climate. Comparison of measured solar radiation intensity with predicted model data demonstrated that the model could precisely predict light radiation intensity over time with different time points and positions in the greenhouse. A series of reflective film configurations were investigated based on features analysis of light distribution in the tomato canopy on sunny days using the proposed model. The reflective film configuration scheme with the highest impact significantly improved the evenness of horizontal and vertical light distribution in tomato canopy. The strategy provided here can be used to configure reflective films that will enhance light conditions in CSG, which can be applied and extended in different scenarios.
中国日光温室内作物生长发育不均直接与冠层内的微光照气候相关。在实际应用中，反光膜用于通过使光分布均匀化从而增加植物总光截获量来改善植物冠层内的微光照气候。然而，据我们所知，对于像反光膜这样的被动反射器对冠层内光分布的贡献尚未进行研究。处理随时间变化的光照条件和生长行为的田间试验实施起来很复杂、耗时且难以控制，然而，准确测量反光膜如何影响冠层的微光照气候是改善任何作物生长条件的关键一步。在此，我们提出一种使用反光膜的补光策略来改善植物冠层内的光分布。以中国日光温室为例，构建了一个包含详细三维番茄冠层结构的三维温室模型，以模拟补光反光膜对改善微光照气候的影响。实测太阳辐射强度与预测模型数据的比较表明，该模型能够精确预测温室中不同时间点和位置随时间变化的光辐射强度。利用所提出的模型，基于晴天番茄冠层内光分布特征分析，研究了一系列反光膜配置。影响最大的反光膜配置方案显著改善了番茄冠层水平和垂直光分布的均匀性。这里提供的策略可用于配置能增强中国日光温室光照条件的反光膜，可在不同场景中应用和推广。
