LED Light Source Characteristics
Plant lighting is the development of facility agriculture to the advanced stage of the inevitable demand, but also to solve the facilities of plant production in the demand for light and the necessary means of supplying light contradictions. In the plant factory production, the traditional plant lighting is generally fluorescent lamps, metal halide lamps, high-pressure sodium lamps and incandescent lamps, these traditional light source is the outstanding shortcomings of energy consumption, high operating costs, energy costs accounted for a high proportion of the total operating costs.
In recent years, with the development of photoelectric technology, especially the high brightness of red, blue and far red semiconductor light-emitting diodes LEDs (light-emitting diodes) was born, so that the application of low-energy artificial light source in the field of agriculture has become possible. As the fourth generation of new lighting source, LED has many different characteristics from other electric light source, which also makes it become the first choice of energy-saving and environmentally friendly light source.
LED use direct current, has a high photoelectric conversion efficiency, long life, small size and high efficiency. LED using direct current, has a high photoelectric conversion efficiency, long life, small size, low energy consumption, wavelength fixed and low heat and other advantages, compared with the current widespread use of high-pressure sodium lamps and fluorescent lamps, not only the optical density, quality of light adjustable, but also low heat of the cold light source, irradiation distance is short, so that the number of cultivation of plants and the utilization of space is greatly improved.
Plant lighting applications in the field of LED also shows the following characteristics:
wavelength type rich, just with plant photosynthesis and light morphology built the spectral range of coincidence;spectral bandwidth of the narrow half-width, according to the different needs of the combination of pure monochromatic light or composite spectra;can be focused on specific wavelengths of the spectrum of the balanced irradiation of the crop;not only to control the growth of the plant and nutrient synthesis, but also regulate the crop blossoming and fruiting;due to the LED system, the light quality is adjustable, and also low heat generation cold light source, short exposure distance, so that the number of plant cultivation layers and space utilization greatly improved. Fruiting;Because the LED system generates less heat and occupies less space, it can be used in multi-layer three-dimensional cultivation combination system to realize low heat load and miniaturization of production space;
In addition, its superior durability also reduces the operating costs. Because of these remarkable features, LED in a controlled facility environment of plant cultivation has a broad application prospects, such as plant tissue culture, facility horticulture and factory nursery and aerospace ecological conservation system. Therefore, LED is considered to be the most promising artificial light source in the field of modern agriculture and biology in the 21st century, and has a good development prospect. It has a good development prospect.
Prospect of LED Application in Plant Factory Cultivation
Because the plant factory is impervious to light closed environment, so artificial lighting has become the most important part of plant production, artificial light source is the only light source for plant plant crop growth. Plant life activities are inseparable from the light environment, and the material basis for plant survival is obtained through photosynthesis. Light is not only the energy source for basic physiological activities such as photosynthesis, but also the power source for bud differentiation, flowering and fruiting.
However, the large energy consumption of artificial light has been a constraint to the large-scale popularization and application of plant factories. The power consumption in artificial light plant factory mainly includes artificial light source, air conditioner, fan, humidifier, control device and other equipment energy consumption, of which the artificial light source is the focus of energy consumption in closed plant factory, the cost usually accounts for about 50%~60% of the overall operating costs. Air-conditioning and refrigeration accounted for 15%, and others accounted for 3%. Reducing the power consumption of artificial light source can not only effectively reduce the operating cost of plant factories, but also accelerate the popularization and application of plant factories.
To reduce the energy consumption of artificial light source, on the one hand, based on the multi-parameter coupling of plant light demand research and optimization of light parameters, light mode optimization, the establishment of lighting light control technology and light control standards suitable for facility cultivation, so as to improve light energy efficiency and reduce energy consumption; on the other hand, new plant light source can be used, such as LED, compared with fluorescent lamps, the use of LED lighting, can enhance the quality of seedlings, improve seedling index, shorten the nursery cycle and reduce the number of seedlings and the number of seedlings.
Compared with fluorescent lamps, LED lighting can enhance seedling quality, improve seedling index, shorten seedling cycle and reduce energy costs, and increase service life by 10 times, save electricity by 69.7% and improve space utilization. Compared with metal halide lamps, in the ground and space plant cultivation using LED lighting energy conversion efficiency increased by about 520 times. At present, especially with the rapid development of photovoltaic technology, the development of new LED light source and supporting regulatory mechanisms emerge in an endless stream, the United States will be applied to the LED light source in the locking life support system, Japan, the Netherlands has been used in the greenhouse LED for supplemental lighting, Israel and Taiwan and other places in the LED light source in the plant plant factory and the research of the group cultivation room.
New LED light source light source are to save energy, reduce costs, suitable for plant growth for the purpose of the scale of plant factory production and commercialization is of great significance, is to improve the reduction of energy consumption of plant production, improve crop yields, as well as increase the economic benefits of plant factories is one of the most effective way.
So far, the research and application of LED in the field of plant facility cultivation in China is still in its infancy, and there is an urgent need for researchers in engineering and plant disciplines to work together to explore the application principles and characteristics of LED in plant facility cultivation, and to develop a LED plant light source in line with China's actual production.
With the development of LED technology and production costs decline year by year, especially with the launch of China's semiconductor lighting project, I believe that in the near future, LED specialized plant light source will be developed successfully, will be widely used in plant cultivation facilities in production practice.