The effect and mechanism of light environment factors such as distribution and photoperiod on the growth of plant seedlings provide a benchmark for the reasonable regulation of light environment in the nursery of factory facilities.
LED plant artificial radiation source (LED-PARS) introduction, LED plant artificial radiation source (LED-PARS) introduction
Sunlight is the source of the survival of all living things. The vitality of the planet we live in is derived from sunlight. The sunlight we see is the visible part of the sun’s electromagnetic radiation. Electromagnetic radiation is when vibration travels at the speed of light. The physical phenomenon of time.
When the wavelength of the vibration wave propagating at the speed of light is from 1 km to 10 picometers, the familiar radio waves, mobile phone communications, microwaves transmitted by televisions, military radars, medical X-rays, gamma rays, etc. are all different. In applications where wavelengths travel at the speed of light, solar radiation is only part of it.
The wavelength range of solar radiation that we can test on the earth is about 295nm-2500nm, solar radiation with wavelengths below 295nm and greater than 2500nm, due to ozone and water in the earth’s atmosphere
The strong absorption of gas and other atmospheric molecules cannot be observed on the ground. When the wavelength is in the range of 400nm-700nm, the human eye can feel the light emitted by these wavelengths, which we call visible light, and solar radiation is mainly
To concentrate on the visible light, solar radiation plays an important role in the life evolution of all living things on the earth. Scientists use spectroscopy to analyze electromagnetic radiation and visible light. We study sunlight, artificial light sources, and plant absorption
The light is inseparable from the spectrogram.
The solar spectrum is only in the range of wavelengths from 300nm to 1100nm. Usually, we divide the spectrum of this range into several parts:
1Ultraviolet: The wavelength ranges from 300nm to 400nm.
2 Visible light: wavelength from 400nm to 700nm.
3 Infrared: wavelength from 700nm to 1100nm.
In terms of agricultural planting, we mainly study the application of wavelengths ranging from 300nm to 1100nm, and the solar spectral radiation distribution curve is an important reference basis.
In the visible light range, the most sensitive light of the human eye (that is, the light we perceive the brightest) is yellow light, and the least sensitive light of the human eye is blue light. When rainbows appear in the sky, we often see yellow, red, and green, and the blue we see is a small part.
The light that plants can "see" needs to be measured by the amount of electromagnetic radiation. Because plants can not only "see" visible light from 400nm-700nm, plants can also "see" invisible light, such as ultraviolet and infrared. This is very important. We use the principle of electromagnetic radiation to study the absorption spectrum of plants, not the concept of light.
The process by which plants convert solar radiation energy into organic matter is called plant photosynthesis. To be precise, photosynthesis refers to plants, algae and certain bacteria that use light energy to convert carbon dioxide (or hydrogen sulfide) and water into photosynthetic pigments. Organic matter, and the biochemical process of releasing oxygen (or hydrogen).
The photosynthetic pigments of plants include chlorophyll a, chlorophyll b and carotenoids. According to the law of conservation of energy conversion, plants convert light energy into chemical energy and store it during photosynthesis. Plant photosynthesis
It needs carbon dioxide and water to complete the process. Under photosynthesis, plants absorb carbon dioxide and water, release oxygen and produce organic matter. Chloroplasts are the place where green plants perform photosynthesis.
The chloroplasts of most plants mainly contain chlorophyll (chlorophyll a and chlorophyll b), β-carotenoids (carotene and lutein), and photosensitizers (Pfr, Pr). Figure 6 is the absorption of light by chloroplasts
In the reflection process, chlorophyll a and chlorophyll b mainly absorb blue-violet light and red light, carotenoids mainly absorb blue-violet light, and photosensitizers mainly absorb red light and far-infrared light. The light absorbed by these pigments can be used for photosynthesis. leaf
The content of chlorophyll is the most, and chlorophyll absorbs very little green light, and most of the green light is reflected, so the chloroplast appears green. The main component of plant leaf tissue is chloroplast, so plant leaves are also green
Colored.
The effective spectral range of photosynthesis of green plants is 380nm-735nm. The photosynthesis of plants mainly absorbs red light and blue light. In addition, there are a small part of ultraviolet and infrared rays, which are the photosynthesis of plants.
Little green light is absorbed. Because the spectrum of sunlight is continuous within the range of plant photosynthesis, the spectrum of plant absorption is also continuous, but the amount of absorption is different.
By analyzing the absorption spectrum of plants, we can use artificial radiation sources with the same wavelength as solar radiation to radiate plants, so as to achieve the same effect of plant photosynthesis as sunlight. This is the basic idea of plant artificial radiation sources.
PARAMETERS
