Agricultural application of hydroponic growth lamps
Due to the impact of climate change, serious natural disasters such as dry mornings, floods and storms occur frequently, and the pests and diseases are more serious, which seriously threatens the sustainable development of agriculture. These threats, accompanied by a shortage of food supplies, have led to a turn to the agricultural production model of Controlled a young culture lighting, indoor farming and urban agriculture (such as vertical agriculture, Vertical farming). The above three agricultural methods eliminate the effects of weather conditions and can be used for annual crop production, which is important for the food supply of the assisted urban population and the future food security of the country (Yeh and Chung, 2009). Based on the photoelectric advantages of hydroponic growth lamps, the application potential of LED in agriculture is huge. The prospect is broad. Agricultural applications of hydroponic growth lamps include both farming and aquaculture. The hydroponic growth lamp can provide light of a specific wavelength, which is helpful for plant photosynthesis and photomorphology, and regulates plant growth and development, yield and nutritional quality formation. In addition, hydroponic growth lamps can regulate the growth and health of livestock and poultry. The study found that broiler chickens were irradiated with green LED or blue LED in the early stage of growth, and blue LED irradiation was used in the late growth stage to significantly promote the growth and development of broilers and improve production performance. Green LED lighting was used in the early growth of broilers to improve the broiler small intestine to varying degrees. Cat membrane structure, improve the ability of the small intestine to absorb nutrients, thereby promoting the growth and development of broilers; blue light, green LED lighting can increase the total area of retina, retinal ganglion cells (RGCs). Numerous studies have shown that through appropriate LED illumination adjustment, it can significantly promote the growth of livestock and poultry, improve its immunity and enhance the production potential of livestock and poultry farming. In short, the application of LED in facility agriculture is feasible and has a good application prospect. Facility gardening is an important part of facility agriculture and is the main industrial direction for hydroponic growth lamps. Artificial light illumination (such as LED plant lights) and greenhouse fill light are important areas of horticultural applications for hydroponic growth light facilities.
The former uses a hydroponic growth lamp as the sole light source to cultivate plants. The latter mainly has two kinds of fill light modes, namely, photoperiodic lighting and Supplemental lighting. Photoperiod fill light requires only low-intensity light (I -25moV lining.). It is applied from sunset to sunrise, including continuous fill and Cyclical lighting. Cyclic fill light refers to providing light to plants intermittently rather than continuously at night (Runkle, 2007). Fill light requires high light intensity. Photoperiod light is commonly used in rootstock plants (inhibiting the flowering of short-day plants), promoting the flowering of long-day plants and inducing early flowering of perennial. High intensity fill light is often used to increase DLI to promote plant photosynthesis. Table 2-11 gives the illumination strategies for the two fill modes. In the northern United States and Canada, the total amount of light per day, or the lack of daylight (DU), is a factor limiting the production of many horticultural crops from October to March of each year. Generally, the minimum average value of DLI should be 10-12 mol/m2·d. If it is less than this value, it will affect the growth quality of plants. For example, the rooting of cutting seedlings is slow, the rooting of plug seedlings is delayed, and the rootstocks have few branches and thin stems. It can be seen from Fig. 2-7 (see color illustration) that below the light saturation point, as the light intensity increases, the net photosynthetic rate of the plant increases, but the rate of increase continues to decrease. So the light-filling benefit is greatest in the dark or when the background light is low. Medium or strong background light intensity is low or zero. Fill light with a DU of 12 to 15 moV resistance and d. LEDs can emit light in a variety of wavelengths, especially the study of the effects of various wavelengths of light on plant growth and development. Finally, the most ideal spectrum for plant growth can be obtained. The illumination system optimizes plant growth and reduces pottery torsion. . At present, the research on the influence of hydroponic growth lamps on the growth and development of greenhouse horticultural crops has been more than 30 years old. The tomb has found out the feasibility and biological basis of LED as an artificial light source for agricultural production. At present, it has been extensively studied in the fields of intensive farming, facility horticulture (plant tissue culture, artificial light plant, seedling breeding, greenhouse light filling, etc.). In recent years, the use of artificial light and chanting to control the light environment (light intensity, light quality and photoperiod) of the horticultural production has been improved, and the photosynthesis of crops has been increased to increase the yield, the effect, the quality, and the foot. purpose. In addition, artificial lighting is one of the means of the two burial construction industry, especially the tourism control. For a long time, artificial light sources such as incandescent lamps and yellow light lamps used in the field of aquaculture have not only consumed more energy, but also difficult to achieve light quality regulation for the physiological needs of livestock and poultry, which restricts the improvement of livestock and poultry production efficiency. Hydroponics growth lamps are Solving these problems provides an opportunity.