Greenhouse, a relatively closed production system, will play an important role in meeting the growing demand for food in the future.
Differences between high - pressure sodium lamps and LED lighting
The difference of luminescence principle and external structure
High pressure sodium lamp from inside to outside by mercury, sodium, xenon arc lamp core, glass shell, the lamp holder and so on. Due to the different ballasts of its core components, they are divided into inductor high-pressure sodium lamps and electronic high-pressure sodium lamps. For high pressure sodium lamps of different powers, ballasts of corresponding specifications should be used. Leds, also known as light-emitting diodes, emit different colors of light from purple to red when the current flows from the anode to the cathode of the LED. The intensity of light depends on the current. Its structure is mainly divided into four parts: the structure of light distribution system, the structure of heat dissipation system, drive circuit and mechanical protection structure.
Differences in exposure range and spectral range
The luminescence Angle of high pressure sodium lamp tube is 360°. Most of them must be reflected by reflector before they can illuminate to the designated area. The spectral energy distribution is roughly red orange light, yellow green light and blue violet light (only a small part). LED light source has adjustable wavelength, can emit light wave narrow monochromatic light, such as infrared, red, orange, yellow, green, blue, etc., can be arbitrary combination according to different needs.
Difference of application condition and life
High pressure sodium lamp is the third generation of lighting source. Conventional alternating current has a wide range of use, high luminous efficiency and strong penetrating ability. Its maximum life span is 24000h. Sodium lamp is a kind of thermal light source. In the process of use, there are also self-extinguishing problems. LED, as a new type of semiconductor light source of the fourth generation, is driven by dc. Its service life can reach more than 50,000h, and its attenuation is small. As a cold light source, it can be close to the irradiation of plants. Comparing LED and high pressure sodium lamp, it is pointed out that LED is safer, contains no harmful elements and is more environmentally friendly.
Difference of influence of high pressure sodium lamp and LED supplementary light on crops
A large number of production practices and scientific research in agricultural production have proved that artificial plants can not only increase crop yield and shorten planting cycle, but also effectively improve crop quality, which is an important guarantee for modern agricultural efficient production. In the process of seedling and greenhouse crop management, high pressure sodium lamp and LED are used to fill the light, which can promote the growth and development of crops and change the yield, shape and physiological indexes of crops.
Yield and quality difference
High yield and high quality of crops is the ultimate goal of cultivation. LED light supplementation can improve the quality of pepper, tomato and eggplant seedlings, and the single fruit quality and yield per plant increase significantly under the condition of 10h light supplementation. The effect of LED light supplement on increasing yield is also shown in cucumber planting. LED can improve the quality of grape fruits, among which, the blue light supplementation treatment has the fastest fruit development, the single grain quality is high, the sugar content is the highest, and the single grain quality is the largest when the ultraviolet light supplementation treatment is mature. High - pressure sodium lamp and LED supplementary light have significant effect on plant morphology. The quality of cucumber visual fruit was also improved by side lighting treatment of LED. In the sodium lamp on the basis of the increase of LED, compared with only sodium lamp processing, cucumber color is more bright.
Morphological index difference
Plant morphological index is an important index in plant growth, especially in seedling production, which determines whether the plant can grow healthily after transplantation and cultivation.
Chlorophyll content directly affects the accumulation of photosynthetic products in leaves. The chlorophyll content of rootstock cotyledon treated by LED for 9 ~ 13 days was significantly higher than that treated by natural light. LED light supplement is beneficial to the accumulation of photosynthetic pigments in Chinese cabbage, and the special spectral ratio in LED can also influence the flowering effect of some plants.
The difference of high pressure sodium lamp and LED production cost
Compared with traditional light source, high pressure sodium lamp and LED have obvious advantages. The top of the plant canopy is illuminated by high pressure sodium lamp and red and blue LED lamp. Both can achieve the same output. The LED only needs to consume 75% energy.