The types of facilities for horticultural facilities mainly include plastic greenhouses, solar greenhouses, multi-span greenhouses and plant factories. Due to the fact that the building construction blocks the natural light source to a certain extent, the indoor light is insufficient, which leads to crop yield reduction and quality degradation. Therefore, the fill light plays an indispensable role in the high quality and high yield of facility crops, but it also becomes a major factor in the increase of energy consumption and operating costs in the facility.
For a long time, artificial light sources used in the field of facilities and horticulture mainly include high-pressure sodium lamps, fluorescent lamps, metal halide lamps, incandescent lamps, etc. The outstanding disadvantages are high heat production, high energy consumption, and high operating costs. The development of a new generation of Light-Emitting Diodes (LEDs) has made it possible to use low-energy artificial light sources in the field of facility horticulture. LED has the advantages of high photoelectric conversion efficiency, use of direct current, small volume, long life, low energy consumption, fixed wavelength, low heat radiation, environmental protection, etc. Compared with the currently used high-pressure sodium lamps and fluorescent lamps, LEDs not only have light quantity and light quality ( The ratio of light in various bands, etc.) can be precisely adjusted according to the needs of plant growth, and because of its cold light, the plants can be irradiated at close range, thereby increasing the number of cultivation layers and space utilization, and achieving energy saving, environmental protection and space that cannot be replaced by conventional light sources. Efficient use and other functions. Based on these advantages, LEDs have been successfully applied to facilities such as horticultural lighting, controlled environment basic research, plant tissue culture, plant factory seedlings and aerospace ecosystems. In recent years, the performance of LED fill lamps has been continuously improved, prices have gradually declined, and various wavelength-specific products have been gradually developed, and its application in agriculture and biology will be broader.