Abstract Diffuse fraction, which can be increased by using diffuse films, has been considered to influence light interception and photosynthesis of crops in greenhouses. However, quantifying the influence of diffuse films is challenging owing to the complicated optical interactions between climatic factors inside and outside greenhouses. Thus, versatile methods for evaluating the effect of diffuse films are required. The objective of this study was to evaluate the effect of diffuse films on the improvement of the light profile and photosynthesis of tomatoes in greenhouses according to film diffuseness and regional solar radiation using ray-tracing simulation. The structural and optical properties of the greenhouse components were applied in a 3D-framework combined with a ray-tracing module. The light transmission patterns of diffuse films and solar radiation properties were incorporated. The reliability of the simulation was confirmed by comparing measured and estimated irradiances inside greenhouses covered with films having different haze factors. For scenarios, the diffuse film efficiency was assessed under typically different solar radiations, a low irradiance, high diffuse radiation fraction (LIHD) and a high irradiance, low diffuse radiation fraction (HILD). The light interception was estimated through the simulation and used to calculate the photosynthesis using the Farquhar-von Caemmerer-Berry model. The simulation was found to be reliable with R2 of 0.95 and 0.94 for the two greenhouses covered with different diffuse films. The light distribution on the tomato plants were less affected by film diffuseness under LIHD than HILD. With increasing film diffuseness, carbon uptake and light use efficiency increased by 5.30% and 4.58% under HILD, but did not change under LIHD. The light distribution and photosynthesis in diffuse film-covered greenhouses under different light environments could be reasonably estimated by the simulation. Thus, this method can be used to evaluate the applicability of diffuse films to various regions with diverse meteorological characteristics.

中文翻译：

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使用光线追踪模拟评估温室番茄植株的光分布和碳同化与薄膜漫射和区域太阳辐射

摘要 漫射分数可以通过使用漫射膜来增加，被认为会影响温室作物的光拦截和光合作用。然而，由于温室内外气候因素之间复杂的光学相互作用，量化漫射膜的影响具有挑战性。因此，需要用于评估漫射膜效果的通用方法。本研究的目的是利用光线追踪模拟，根据薄膜漫射度和区域太阳辐射，评估漫射膜对改善温室番茄光分布和光合作用的影响。温室组件的结构和光学特性被应用于与光线追踪模块相结合的 3D 框架中。漫射膜的透光模式和太阳辐射特性被纳入。通过比较覆盖有不同雾度系数的薄膜的温室内的测量和估计辐照度，证实了模拟的可靠性。对于场景，漫射膜效率是在典型的不同太阳辐射、低辐照度、高漫射辐射分数 (LIHD) 和高辐照度、低漫射辐射分数 (HILD) 下评估的。光拦截是通过模拟估算的，并用于使用 Farquhar-von Caemmerer-Berry 模型计算光合作用。对于覆盖有不同漫射膜的两个温室，该模拟被发现在 R2 为 0.95 和 0.94 时是可靠的。与 HILD 相比，LIHD 下番茄植株的光分布受薄膜扩散的影响较小。随着薄膜扩散度的增加，碳吸收和光利用效率在 HILD 下分别增加了 5.30% 和 4.58%，但在 LIHD 下没有变化。通过模拟可以合理估计不同光照环境下漫射覆膜温室的光分布和光合作用。因此，该方法可用于评估漫射膜对具有不同气象特征的各个区域的适用性。通过模拟可以合理估计不同光照环境下漫射覆膜温室的光分布和光合作用。因此，该方法可用于评估漫射膜对具有不同气象特征的各个区域的适用性。通过模拟可以合理估计不同光照环境下漫射覆膜温室的光分布和光合作用。因此，该方法可用于评估漫射膜对具有不同气象特征的各个区域的适用性。