In recent years, the global sunshine time has been decreasing. Take Taiwan, China as an example, the recent sunshine time is less than 61 years. Reduced sunshine time is very detrimental to agricultural development. With the continuous development of production technology and the increasing demand for increasing plant yield and shortening the planting cycle, artificial light sources have begun to be applied in the field of plant cultivation.
"Artificial Sunshine" Creates Miracles
Studies have found that many plants only need red and blue light in their growth process. LEDs emit light at all wavelengths. Compared with full-spectrum sunlight, researchers can "distribute" light so that they only receive "artificial sunlight" in certain wavelength ranges. Therefore, in this 200 square metre "plant factory", the researchers only irradiate the plants with blue and red light. LED lasts 24 hours, and plants continue to photosynthesize even at night. Under such circumstances, the growth rate of plants has been greatly increased. Vegetables that originally took 52 to 60 days to grow ripened 20 days after using LED plant growth lights.
Replacing sunlight with LED lamps increases the production cost of plants, but it does not mean that farmers benefit less. Because there is no need to eat by day, in the laboratory, plants are vertically distributed into 2-5 layers, each layer has LED light source, this design mode, so that the unit yield of crops is greatly increased. Researcher Li Yuanzhi said that the increase in output value could offset the increase in costs and ultimately benefit farmers.
Japan's central government and local autonomous bodies (prefectural roads) have been counseling local agricultural practitioners since 2011 to develop plant factories to compensate for the lack of sunshine through LED lighting. Japan has also studied the use of LED lighting in poultry farming facilities. Studies have found that using yellow LED lighting can save costs and reduce the aggressiveness of poultry. In the Netherlands, where "multi-layer cultivation" is actively promoted, the LED auxiliary light source is often seen in the cultivation of lettuce seedlings and tulips. Because the lower layer is harder to get sunlight than the upper layer in multi-layer cultivation, Dutch farmers mostly use LED lights to supplement the lack of sunlight.
Advantages of LED Plant Lighting
Compared with traditional plant lighting, the advantages of LED plant lighting are high efficiency and energy saving. For example, the experiment of adding light by LED in Greenhouse in the Netherlands shows that compared with traditional high-pressure sodium lamp and metal halogen lamp, LED can save 50%~80% energy. In plant factories, using traditional light sources requires 0.5 kilowatts of light per square metre, whereas LED only needs 0.27 kilowatts. In the field of tissue culture, the total area of tissue culture in China is more than 20 million square meters. If the light time of tissue culture is 16h/d and the production day is 300 days per year, the total annual power consumption caused by fluorescent lamp is more than 107.5 billion degrees; after using LED, the total annual power consumption is about 51.8 billion degrees, and the total annual power saving is more than 56 billion degrees. In addition to acting as "light fertilizer", LED lighting also has great application space in other areas of agriculture.
For physical control of agricultural pests, special wavelength LED light source can be used to induce and kill pests and reduce the dosage of pesticides; for animal breeding, specific wavelength LED light can be used to promote animal productivity and reduce the use of feed additives and hormones according to different breeding purposes; For marine fishing, the specific wavelength of LED light source can be used to induce seafood and improve the fishing capacity; for microorganisms, the specific wavelength of LED light can be used to promote the proliferation of beneficial microorganisms to achieve high efficiency and intensive production of microbial reaction process.
The Prospect of LED Plant Lighting
At present, plant lighting is mainly used in plant factories, plant landscape and breeding lighting. Plant factories are the main and relatively mature market for plant lighting. Taking Shenzhen as an example, five plant factories can supply daily vegetable, melon and fruit consumption throughout Shenzhen. Plant landscape is in the initial stage of entering the market. Although the market potential of breeding lighting is huge, the market has not been developed at present.
China is the fourth largest plant factory country in the world. In the future, the prospect of LED plant lighting is considerable. The plant factory seedling industry alone provides a huge consumer market for LED light source. The export of seedlings alone has reached nearly 10 billion plants. The annual consumption of the mainland is even greater. If the traditional electricity is replaced by LED in plant factory seedling breeding, the annual consumption of the mainland will be greater. The total one-off market of light source will reach 200 billion yuan.
As the Japanese market is leading in plant lighting progress, technology and enthusiasm, Japan has estimated that by 2020, the output value of plant LED lighting market will reach 300 billion yen a year (equivalent to about 23.6 billion yuan), and the output value of plant breeding as a whole will reach 3 trillion yen, which can not be underestimated. The attraction of the market attracts many manufacturers at home and abroad to enter agricultural lighting. By the end of June 2012, there were about 40 LED plant lighting enterprises with a certain scale in China. In 2009, there were only two or three enterprises engaged in LED plant lighting in China.
Domestic market needs to be opened up urgently
Despite the bright prospects, there is still a long way to go to achieve it. According to the statistics of GLII, the output value of LED plant lighting in China in 2011 was only 300 million yuan. Compared with the output value of hundreds of billions of ordinary lighting, this figure can only be described as "small witches see big witches". Of the output value of 300 million yuan, more than 90% are exports. The sales market is mainly concentrated in Japan, Korea, China, the United States, Europe and other countries and regions which are less engaged in agriculture. The domestic market of plant lighting is expanding.
