Department of Greenhouse Horticulture, Wageningen University and Research Centre Wageningen, Netherlands.
Institut de Recherche en Horticulture et Semences AGROCAMPUS OUEST, Angers, France.
Front Plant Sci. 2014 Feb 18;5:48. doi: 10.3389/fpls.2014.00048. eCollection 2014.
Reduction of energy use for assimilation lighting is one of the most urgent goals of current greenhouse horticulture in the Netherlands. In recent years numerous lighting systems have been tested in greenhouses, yet their efficiency has been very difficult to measure in practice. This simulation study evaluated a number of lighting strategies using a 3D light model for natural and artificial light in combination with a 3D model of tomato. The modeling platform GroIMP was used for the simulation study. The crop was represented by 3D virtual plants of tomato with fixed architecture. Detailed data on greenhouse architecture and lamp emission patterns of different light sources were incorporated in the model. A number of illumination strategies were modeled with the calibrated model. Results were compared to the standard configuration. Moreover, adaptation of leaf angles was incorporated for testing their effect on light use efficiency (LUE). A Farquhar photosynthesis model was used to translate the absorbed light for each leaf into a produced amount of carbohydrates. The carbohydrates produced by the crop per unit emitted light from sun or high pressure sodium lamps was the highest for horizontal leaf angles or slightly downward pointing leaves, and was less for more upward leaf orientations. The simulated leaf angles did not affect light absorption from inter-lighting LED modules, but the scenario with LEDs shining slightly upward (20(°)) increased light absorption and LUE relative to default horizontal beaming LEDs. Furthermore, the model showed that leaf orientation more perpendicular to the string of LEDs increased LED light interception. The combination of a ray tracer and a 3D crop model could compute optimal lighting of leaves by quantification of light fluxes and illustration by rendered lighting patterns. Results indicate that illumination efficiency increases when the lamp light is directed at most to leaves that have a high photosynthetic potential.
减少同化照明的能源消耗是目前荷兰温室园艺最紧迫的目标之一。近年来，许多照明系统在温室中进行了测试，但实际上很难测量其效率。本模拟研究使用自然光和人工光的 3D 光模型以及番茄的 3D 模型评估了几种照明策略。建模平台 GroIMP 用于模拟研究。作物由具有固定结构的番茄 3D 虚拟植物表示。模型中包含了有关温室结构和不同光源灯发射模式的详细数据。使用校准模型对多种照明策略进行了建模。将结果与标准配置进行了比较。此外，还结合了叶片角度的适应性，以测试其对光利用效率 (LUE) 的影响。Farquhar 光合作用模型用于将每个叶片吸收的光转化为产生的碳水化合物量。作物每单位发出的阳光或高压钠灯的光产生的碳水化合物最多为水平叶片角度或稍微向下指向的叶片，而向上的叶片方向则较少。模拟叶片角度不会影响来自照明 LED 模块的光吸收，但与默认水平发射 LED 相比，向上轻微照射（20(°)）的 LED 情景增加了光吸收和 LUE。此外，该模型表明，与 LED 串更垂直的叶片方向增加了 LED 光的拦截。光线追踪器和 3D 作物模型的组合可以通过量化光通量并通过渲染照明模式进行说明来计算叶片的最佳照明。结果表明，当灯光主要指向具有高光合潜力的叶片时，照明效率会提高。
