PAR (Photosynthetically Active Radiation) Performances in Greenhouses: A Climate-Based Investigation Across China
Abstract
Photosynthetically Active Radiation (PAR) is critically required for sustaining plant and vegetable growth. This study investigated the PAR performances in two typical large-scale greenhouses using an advanced method of climate-based solar modelling in China. Eight Chinese locations defined in terms of daylight zones and latitudes were studied. The solar simulation was conducted via RADIANCE (ray-tracing solar and light simulation package). Key findings are: 1) In general, PAR availability in the greenhouses is significantly linked to both locations and daylight zones in China. Compared with the daylight zone, PAR variations expressed a higher sensitivity to the location. 2) At most locations, A-frame greenhouse can deliver a relatively higher PAR availability than Barrel-vault model, especially for the locations within the daylight zones of I, II and III. These results could be considered when planning a passive solution for greenhouse constructions in China or regions with similar climate conditions.