Ordinary ice lamps for plants. LED lamps for plants. We fix the LEDs on the profile
Recently, in the field of indoor gardening, interest in and has been growing. Diodes have low power consumption, do not heat up as much as HPS, do not require additional devices for connection. In this article, we will try to deal with the pros and cons of this type of lamp and understand where and what is the benefit for the gardener.
LED (Light Emitting Diode) It is a semiconductor device that distorts electrical voltage into light. The spectral range of the emitted light depends on the chemical composition of the semiconductor. In appearance, it is almost an ordinary lamp with a lot of LEDs in it. These things were invented back in 1907, but for the needs of crop production they were finalized relatively recently. Despite the fact that LED plant lamps have just entered our lives, they have already managed to establish a good reputation for themselves.
How to choose LED lighting for a grow box?
- blue spectrum 430-455 nm, used for lighting during the growing season (blue-violet range helps in the creation of growth inhibitors that contribute to the formation of the plant, increase its density and strength);
- red spectrum 660 nm, used at the flowering stage of plants (the red-orange wavelength range is responsible for the development of fruits, roots, and the increase in the volume of tops).
The remaining ranges are much less effective for backlighting.
For different types of plants, as well as stages of their growth, different ratios of the blue and red components of the spectrum are needed. Therefore, when choosing an LED panel or lamp, it is necessary to take into account the emission spectrum. It is better to choose multispectral LED lamps, otherwise you will have to buy one unit for the vegetative stage of plant development and the second for flowering.
The second important characteristic when choosing an LED is power. It must be selected, starting from the required area of \u200b\u200blighting. Consider the common types of LED devices and their characteristics:
- Fitolamps with a power of 5-15 W - well suited for supplementary lighting of one or two plants, illuminate an area up to 0.5 sq. m.; Phytolamps with a power of 21-27 W - cover an area up to 0.6-0.65 square meters with light.
- A round LED phytolamp with a power of 80-150 W is perfect for additional lighting of plants.
- Rectangular LED lights from 150W to 800W will be the best solution for full lighting of plants, without the use of natural light.
- Phyto tapes are an advantageous solution in terms of price and quality, which is suitable only for supplementary lighting of plants; natural lighting cannot be replaced by them.
Benefits of LED Plant Lighting
- LED panels and phytolights are great for home greenhouses, winter gardens, grow tents, because they emit much less heat (compared to HPS). Therefore, when using them, a separate fan is not required to remove hot air, as with sodium lamps. The optimal suspension height is 30-50 cm from the upper leaves of the plant.
- LED luminaires do not require additional devices, such as ballasts and IZU, which are necessary for connecting sodium lamps. LED panels and luminaires are connected with a standard wire directly to the 220V network, thanks to which the risk of fire or short circuit practically disappears.
- Due to its design, the LED forms a strictly directed beam of light and a reflector (reflector) is not required for it.
- LED lamps consume 4-5 times less electricity than sodium lamps. The power consumption declared by the manufacturer will actually be even lower, since it only indicates the size of the crystal and its potential, and less current is supplied. For example, the actual power consumption of a lamp is 15W = 8.5W.
- Long service life - up to 50,000 hours. Provided that the lamp or lamp you have chosen will not overheat and burn out.
- Fast installation.
- It does not require constant monitoring and preliminary preparation of the area for placement.
- Diode illumination of plants is harmless to humans and the environment - it does not contain mercury and other hazardous substances.
Disadvantages of LED
The main limiting factor in the spread of this type of lighting is the price. Let's compare the cost of a lamp (power 140 W, lighting area about 60 * 60 cm) and a set of HPS 250 W (Super HPS lamp 250 W + EMPRA 1-K-250W + indoor lamp CoolMaster 100 + fan GARDEN HIGHPRO 160). LED Apollo 4 costs 15,600 rubles, a DNAT kit costs 11,700 rubles.
Well, if you purchase separate blocks of LEDs for the vegetative stage and for flowering, then, ultimately, this will lead to an even greater rise in the cost of the lighting system.
The second common problem with LEDs is overheating and, as a result, burnout. Therefore, it is better to choose a luminaire with active cooling. These include Apollo phytolamps, which we will discuss later.
It is better not to save on the purchase of LED lamps. Choose LEDs with a guarantee from reliable manufacturers, read reviews. As a rule, cheap Chinese LEDs quickly fail, and it is difficult to repair them, because few people do it.
Apollo LED lamps
Apollo is a multi-spectral, complete luminaire that illuminates plants throughout their entire life cycle. Diodes in Apollo lamps work in five spectra. Diode color per segment (nm*pcs): 660*3, 630*6, 470*3, 595*1, 6500*2. According to the manufacturer, the Apollo 4 lamp works with the same performance as a 420 W HPS lamp.
Well, to top it off, we publish the spectrogram of the Apollo 140 lamp, HPS lamps 150 W and 250 W.
As you can see, the peak in the blue area of LED Apollo 140 is much higher, which will favorably affect the vegetative development of the plant. LED Apollo 140 has a clearly defined peak in the red region, while for HPS 150 and 250 it is shifted closer to the yellow spectrum, which is less effective for plant development. The indicator of PAR (total photosynthetically active radiation) for the Apollo 140 LED and the 250 W HPS lamp is generally comparable - 161 versus 172.
Conclusion: with equally absorbed watts, the LED Apollo luminaire produces more "useful" lighting than HPS 150 and 250 W.
Hybrid Lighting - LED + HPS
When growing high-yielding plant hybrids, the combination of HPS + LED can give a significant increase in yield. Let's consider in more detail.
So. DNAT lamps with a power of 400 W and above give a powerful stream of red light, which is so important for flowering and fruiting. In addition, HPS is much more multispectral than red-blue diode lamps. LED, on the other hand, emits a minimum of heat - the working surface of a 280W LED lamp barely reaches 40 degrees compared to 200 degrees HPS, and this is a huge advantage. Thus, if you use a powerful HPS stream and illuminate the sides with LED panels, the HPS performance in lumens will increase from 60,000-95,000 to 100,000-160,000 without raising the temperature in the grow room and saving energy!
At the moment, in western growports, you can increasingly find the type of lighting: 1 HPS and several LED lamps. The result is previously unthinkable!
To consolidate the information, watch the video from our YouTube channel:
The intensity of photosynthesis under red light is maximum, but under red light alone, plants die or their development is disturbed. For example, Korean researchers have shown that when illuminated with pure red, the mass of grown lettuce is greater than when illuminated with a combination of red and blue, but the leaves contain significantly less chlorophyll, polyphenols, and antioxidants. And the Biological Faculty of Moscow State University found that in the leaves of Chinese cabbage under narrow-band red and blue light (compared to illumination with a sodium lamp), the synthesis of sugars decreases, growth is inhibited and flowering does not occur.
Rice. 1 Leanna Garfield, Tech Insider - Aerofarms
What kind of lighting is needed to get a fully developed, large, fragrant and tasty plant with moderate energy consumption?
How to evaluate the energy efficiency of a lamp?
The main metrics for assessing the energy efficiency of phytolight:
- Photosynthetic Photon Flux (PPF), in micromoles per joule, i.e., in the number of light quanta in the range of 400–700 nm, which were emitted by a lamp that consumed 1 J of electricity.
- Yield Photon Flux (YPF), in effective micromoles per joule, i.e., in the number of quanta per 1 J of electricity, taking into account the factor - the curve McCree.
HPS efficiency
Large agricultural enterprises with vast experience, counting money, still use sodium lamps. Yes, they willingly agree to hang LED lamps provided to them over the experimental beds, but they do not agree to pay for them.
From fig. 2 it can be seen that the efficiency of a sodium lamp strongly depends on the power and reaches a maximum at 600 W. Typical optimistic value YPF for a sodium lamp 600-1000 W is 1.5 eff. µmol/J. Sodium lamps 70–150 W have one and a half times less efficiency.
Rice. 2. Typical spectrum of a sodium lamp for plants (left). Efficiency in lumens per watt and in effective micromoles of commercial sodium lamps for greenhouse brands Cavita, E Papillon, "Galad" and "Reflax" (on right)
Any LED lamp with an efficiency of 1.5 eff. µmol/W and an acceptable price can be considered a worthy replacement for a sodium lamp.
Doubtful effectiveness of red-blue phytolamps
In this article, we do not present the absorption spectra of chlorophyll because it is incorrect to refer to them in a discussion of the use of the light flux by a living plant. Chlorophyll in vitro, isolated and purified, does only absorb red and blue light. In a living cell, pigments absorb light in the entire range of 400–700 nm and transfer its energy to chlorophyll. The energy efficiency of light in a sheet is determined by the curve " Mc Cree 1972» (Fig. 3).
Rice. 3. V(λ) - visibility curve for a person; RQE is the relative quantum efficiency for the plant ( McCree 1972); σ r And σ fr- absorption curves of red and far red light by phytochrome; B(λ) - phototropic efficiency of blue light
Note: the maximum efficiency in the red range is one and a half times higher than the minimum - in the green one. And if you average the efficiency over a somewhat wide band, the difference becomes even less noticeable. In practice, the redistribution of part of the energy from the red range to the green range sometimes, on the contrary, enhances the energy function of light. Green light passes through the thickness of the leaves to the lower tiers, the effective leaf area of the plant increases dramatically, and the yield of, for example, lettuce increases.
Plant lighting with white LEDs
The energy feasibility of lighting plants with common white light LED lamps was studied in the work.
The characteristic spectrum shape of a white LED is determined by:
- balance of short and long waves, correlated with color temperature (Fig. 4, left);
- the degree of spectrum occupancy, which correlates with color rendering (Fig. 4, right).
Rice. 4. Spectra of white LED light with the same color rendering but different CCT color temperatures (left) and with the same color temperature and different color rendering Ra (on right)
Differences in the spectrum of white diodes with the same color rendering and the same color temperature are barely perceptible. Therefore, we can evaluate spectrum-dependent parameters only by color temperature, color rendering and luminous efficiency - the parameters that are written on the label of a conventional white light lamp.
The results of the analysis of the spectra of serial white LEDs are as follows:
1. In the spectrum of all white LEDs, even with a low color temperature and with maximum color rendering, like sodium lamps, there is very little far red (Fig. 5).
Rice. 5. White LED spectrum ( LED 4000K Ra= 90) and sodium light ( HPS) in comparison with the spectral functions of the plant's susceptibility to blue ( B), red ( A_r) and far red light ( A_fr)
Under natural conditions, a plant shaded by a canopy of alien foliage receives more far red than near, which in light-loving plants triggers the "shade avoidance syndrome" - the plant stretches up. Tomatoes, for example, at the stage of growth (not seedlings!) Far red is needed to stretch out, increase growth and the total area occupied, and hence the yield in the future.
Accordingly, under white LEDs and under sodium light, the plant feels like under the open sun and does not stretch upwards.
2. Blue light is needed for the "tracking the sun" reaction (Fig. 6).
Rice. 6. Phototropism - turning leaves and flowers, stretching the stems to the blue component of white light (illustration from Wikipedia)
In one watt of the 2700 K white LED light flux, there are twice as many phytoactive blue components as in one watt of sodium light. Moreover, the proportion of phytoactive blue in white light increases in proportion to the color temperature. If, for example, decorative flowers need to be turned towards people, they should be illuminated from this side with intense cold light, and the plants will unfold.
3. The energy value of light is determined by the color temperature and color rendering and can be determined with an accuracy of 5% by the formula:
where is the luminous efficacy in lm/W, is the overall color rendering index, is the correlated color temperature in degrees Kelvin.
Examples of using this formula:
A. Let us estimate for the main values of the parameters of white light, what should be the illumination in order to provide, for example, 300 eff. for a given color rendering and color temperature. µmol/s/m2:
It can be seen that the use of warm white light of high color rendering allows the use of somewhat lower illumination. But if we take into account that the luminous efficiency of warm light LEDs with high color rendering is somewhat lower, it becomes clear that it is impossible to win or lose energetically significantly by choosing the color temperature and color rendering. You can only adjust the proportion of phytoactive blue or red light.
B. Assess the applicability of a typical general purpose LED grow light for microgreens.
Let a luminaire with a size of 0.6 × 0.6 m consume 35 W, have a color temperature of 4000 TO, color rendering Ra= 80 and light output 120 lm/W. Then its efficiency will be YPF= (120/100)⋅(1.15 + (35⋅80 − 2360)/4000) eff. µmol/J = 1.5 eff. µmol/J. Which, when multiplied by the consumed 35 W, will be 52.5 eff. µmol/s.
If such a luminaire is lowered sufficiently low over a microgreen bed with an area of 0.6 × 0.6 m = 0.36 m 2 and thereby avoiding light loss to the sides, the illumination density will be 52.5 eff. µmol / s / 0.36m 2 \u003d 145 eff. µmol/s/m 2 . This is about half the commonly recommended values. Therefore, the power of the lamp must also be doubled.
Direct comparison of phytoparameters of lamps of different types
Let's compare the phytoparameters of a conventional office LED ceiling lamp manufactured in 2016 with specialized phytolamps (Fig. 7).
Rice. 7. Comparative parameters of a typical 600W sodium lamp for greenhouses, a specialized LED phytolamp and a lamp for general lighting of premises
It can be seen that a conventional general lighting lamp with a diffuser removed when illuminating plants is not inferior in energy efficiency to a specialized sodium lamp. It can also be seen that the red-blue light phytolamp (the manufacturer is not named intentionally) is made at a lower technological level, since its full efficiency (the ratio of the luminous flux power in watts to the power consumed from the network) is inferior to the efficiency of an office lamp. But if the efficiency of the red-blue and white lamps were the same, then the phytoparameters would also be approximately the same!
It can also be seen from the spectra that the red-blue phytolamp is not narrow-band, its red hump is wide and contains much more far red than that of a white LED and sodium lamp. In cases where far red is required, the use of such a luminaire alone or in combination with other options may be appropriate.
Assessment of the energy efficiency of the lighting system as a whole:
Rice. 8. Phyto-lighting system audit
next model UPRtek- spectrometer PG100N according to the manufacturer, it measures micromoles per square meter, and, more importantly, the luminous flux in watts per square meter.
Measuring the luminous flux in watts is an excellent feature! If you multiply the illuminated area by the luminous flux density in watts and compare it with the consumption of the lamp, the energy efficiency of the lighting system becomes clear. And this is the only indisputable criterion of efficiency for today, in practice for different lighting systems it differs by an order of magnitude (and not by several times or even more so by percentages, as the energy effect changes when the spectrum shape changes).
Examples of using white light
Examples of illumination of hydroponic farms with both red-blue and white light are described (Fig. 9).
Rice. 9. From left to right and top to bottom farms: Fujitsu, Sharp, Toshiba, a medicinal plant farm in Southern California
The truss system is well known Aerofarms(Fig. 1, 10), the largest of which was built near New York. under white LED lights Aerofarms grow more than 250 types of greenery, harvesting more than twenty crops a year.
Rice. 10. Farm Aerofarms in New Jersey ("Garden State") on the border with New York
Direct experiments comparing white and red-blue LED lighting
There are very few published results of direct experiments comparing plants grown under white and red-blue LEDs. For example, a glimpse of such a result was shown by the Moscow Agricultural Academy. Timiryazev (Fig. 11).
Rice. eleven. In each pair, the plant on the left is grown under white LEDs, on the right - under red-blue (from presentations I. G. Tarakanova, Department of Plant Physiology, Moscow Agricultural Academy. Timiryazev)
Beijing Aviation and Space University published the results of a large study of wheat grown under different types of LEDs in 2014. Chinese researchers concluded that it is advisable to use a mixture of white and red light. But if you look at the digital data from the article (Fig. 12), you notice that the difference in parameters for different types of lighting is by no means radical.
Figure 12. The values of the studied factors in two phases of wheat growth under red, red-blue, red-white and white LEDs
However, the main focus of research today is to correct the shortcomings of narrow-band red-blue illumination by adding white light. For example, Japanese researchers have found an increase in the mass and nutritional value of lettuce and tomatoes when white is added to red light. In practice, this means that if the aesthetic appeal of the plant during growth is not important, it is not necessary to refuse already purchased narrow-band red-blue lamps, white light lamps can be used additionally.
Influence of light quality on the result
The fundamental law of ecology "Liebig's barrel" (Fig. 13) states: development limits the factor that deviates more than others from the norm. For example, if water, minerals and SO 2, but the light intensity is 30% of the optimal value - the plant will give no more than 30% of the maximum possible yield.
Rice. 13. An illustration of the limiting factor principle from tutorial video on YouTube
The reaction of the plant to light: the intensity of gas exchange, the consumption of nutrients from the solution and the processes of synthesis - is determined by the laboratory. Responses characterize not only photosynthesis, but also the processes of growth, flowering, synthesis of substances necessary for taste and aroma.
On fig. 14 shows the response of a plant to a change in the wavelength of light. The intensity of consumption of sodium and phosphorus from the nutrient solution of mint, strawberries and lettuce was measured. Peaks in such graphs are signs of stimulation of a particular chemical reaction. The graphs show what to exclude from the full spectrum for the sake of saving some ranges - it's like removing some of the piano keys and playing a melody on the rest.
Rice. 14. Stimulating role of light for nitrogen and phosphorus uptake by mint, strawberries and lettuce (data provided by Fitex)
The principle of the limiting factor can be extended to individual spectral components - for a full-fledged result, in any case, a full spectrum is needed. Withdrawal from the full spectrum of some ranges does not lead to a significant increase in energy efficiency, but the "Liebig barrel" may work - and the result will be negative.
The examples demonstrate that ordinary white LED light and specialized "red-blue phytolight" have approximately the same energy efficiency when illuminating plants. But broadband white comprehensively satisfies the needs of the plant, which are expressed not only in the stimulation of photosynthesis.
Removing green from the continuous spectrum to turn the light from white to purple is a marketing ploy for buyers who want a "special solution" but are not qualified customers.
white light correction
The most common general purpose white LEDs have poor color rendering. Ra= 80, which is primarily due to the lack of red color (Fig. 4).
The lack of red in the spectrum can be filled by adding red LEDs to the lamp. Such a solution promotes, for example, CREE. The logic of Liebig's barrel suggests that such an addition will not hurt if it is really an addition, and not a redistribution of energy from other ranges in favor of red.
Interesting and important work was done in 2013–2016 by the Institute of Biomedical Problems of the Russian Academy of Sciences: they studied how the addition of white LEDs 4000 to the light affects the development of Chinese cabbage TO / Ra= 70 light narrowband red LEDs 660 nm.
And found out the following:
- Under LED light, cabbage grows in much the same way as under sodium, but it has more chlorophyll (leaves are greener).
- The dry weight of the crop is almost proportional to the total amount of light in moles received by the plant. More light - more cabbage.
- The concentration of vitamin C in cabbage slightly increases with increasing illumination, but significantly increases with the addition of red to white light.
- A significant increase in the proportion of the red component in the spectrum significantly increased the concentration of nitrates in the biomass. I had to optimize the nutrient solution and introduce part of the nitrogen in the ammonium form, so as not to go beyond the MPC for nitrates. But in pure white light, it was possible to work only with the nitrate form.
- At the same time, an increase in the proportion of red in the total luminous flux has almost no effect on the mass of the crop. That is, the replenishment of the missing spectral components does not affect the quantity of the crop, but its quality.
- The higher efficiency in moles per watt of a red LED means that adding red to white is also energetically efficient.
Options for enriching the spectrum with red light
The plant does not know where the quantum from the spectrum of white light came from, and where the "red" quantum came from. There is no need to make a special spectrum in one LED. And there is no need to shine with red and white light from one of some special phytolamps. It is enough to use general-purpose white light and additionally illuminate the plant with a separate red light lamp. And when there is a person next to the plant, the red lamp can be turned off by the motion sensor to make the plant look green and pretty.
But the reverse decision is also justified - having selected the composition of the phosphor, expand the spectrum of the white LED glow towards long waves, balancing it so that the light remains white. And you get white light with extra high color rendering, suitable for both plants and humans.
Open questions
It is possible to identify the role of the ratio of far and near red light and the appropriateness of using the “shadow avoidance syndrome” for different cultures. It can be argued into which sections it is advisable to divide the wavelength scale in the analysis.
It can be discussed whether the plant needs wavelengths shorter than 400 nm or longer than 700 nm for stimulation or regulatory function. For example, there is a private message that ultraviolet significantly affects the consumer qualities of plants. Among other things, red-leaf lettuce varieties are grown without ultraviolet light, and they grow green, but before being sold, they are irradiated with ultraviolet light, they turn red and go to the counter. Is the new metric correct? PBAR (plant biologically active radiation) described in the standard ANSI/ASABE S640, Quantities and Units of Electromagnetic Radiation for Plants (Photosynthetic Organisms, prescribes to take into account the range of 280–800nm.
Conclusion
Chain stores choose more stale varieties, and then the buyer votes with a ruble for brighter fruits. And almost no one chooses the taste and aroma. But as soon as we become richer and start demanding more, science will instantly provide the right varieties and nutrient solution recipes.
And in order for the plant to synthesize everything that is needed for taste and aroma, lighting with a spectrum containing all the wavelengths to which the plant will react, i.e., in the general case, a continuous spectrum, will be required. Perhaps the basic solution will be high color rendering white light.
Thanks
The author expresses his sincere gratitude for the help in preparing the article to the researcher of the State Scientific Center of the Russian Federation-IMBP RAS, Ph.D. n. Irina Konovalova; Tatyana Trishina, Head of the Fitex project; company specialist CREE Mikhail Chervinsky
Literature
Literature
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In winter, there are very few sunny days, and the length of daylight hours is short. At this time, houseplants and seedlings grown by gardeners begin to experience light hunger. The light they get from ordinary room lights cannot replace the natural light of the sun. Rescue lamps equipped with LED lamps for plants, giving a luminous flux close to natural.
What lamps can be used
For fixtures suitable for use in order to additionally illuminate domestic plants or seedlings, you can take lamps of any type. At the same time, their effectiveness will be different, as well as durability. Can be considered all possible options:
The design of the LED phytolamp
The lamp itself is constructed from a set of LEDs. The human eye sees only a white glow during their work. In fact, individual light waves travel in a multi-colored stream. Those plants that are just starting to grow need a blue glow corresponding to a light wavelength of four hundred and thirty to four hundred and fifty nanometers. The same plantings that begin to bloom require a red glow (six hundred and sixty nanometers).
Phytolamps with LEDs
Such lighting fixtures have found application in homes where indoor flower lovers or gardeners grow seedlings. Vegetable crops occupy a significant space and require a large amount of light feeding. After planting in open ground during flowering, LEDs are used to help fruit set. LED grow lights have a lot of advantages that distinguish them from other lighting equipment:
With so many compelling benefits, it seems that the final choice of device is a foregone conclusion. However, many are stopped by the only drawback of a phytolamp with an LED emitter - this is its high cost. Not every amateur gardener will be able to pay two hundred dollars for a simple lighting fixture, not to mention more advanced and efficient models. A professional producer of seedlings of vegetables or flowers will go to such costs.
Illumination of plants with LEDs
To establish auxiliary lighting for plants, it is necessary to understand the mode of growth phases of future plantings. There are plants that are indifferent to the change of day to night, others are very sensitive to the untimely change of lighting regime.
If you make a mistake, then the photosynthesis of green spaces will be disrupted and their development will slow down. Therefore, the correct selection of lighting fixtures is a guarantee of the future harvest.
seedling LED
In order to take advantage of the fruits of labor in growing vegetables, you have to start when it is winter outside. It was at this time that experienced gardeners start sowing seeds and rearing of emerging seedlings.
For tiny tender sprouts, it is necessary to create a favorable microclimate, which to a large extent depends on the quality and illumination regime of the landing site. LEDs in combination with automatic equipment as part of special lighting devices make it possible not only to provide the necessary spectral wavelength, but also the length of the conditional day and night for young growth. And a slight heat release allows you to place them so close to the ground to cover the entire area occupied by the sprouts and not damage the leaves.
Greenhouse lighting
After planting a little stronger plants under the protection of greenhouse plants, the conditions of artificial lighting also change. It also requires maintaining the daily phase of growth, but in addition, to accelerate vegetative growth, it is necessary to observe changes in the range of illumination. In greenhouses, most often the microclimate is hot and humid, which is unsafe for lighting devices.
Such working conditions are not terrible for LED lighting devices. Most often, LED strip is used for such purposes. It satisfies all requirements.
In addition, due to the self-adhesive base, it is easily attached in the right place. However, this method is not very efficient. The result will be noticeable after using a special complex device for such purposes.
Principles of influence on plants
The rhythm of growth and development of plants dictates certain canons for the use of additional illumination. By the same rules you need to follow when placing LED phytolamps in your greenhouse or greenhouse:
That greenery that goes into hibernation for the winter (for example, the Decembrists), the conventional daytime is reduced to eight to ten hours. Shade-loving plants do not need bright lighting. A device with a luminous flux of three hundred lux is enough. And vice versa, for those who love light, powerful illuminators of six to seven thousand lux are bought.
Number of fixtures
The number of light sources is determined by several conditions:
Before buying, you need to determine the degree of light-loving plants planned for growing. Devices should be chosen so that they provide even illumination over the entire area of \u200b\u200bthe nursery. It is necessary to be able to adjust the suspension distance of the lamp.
Then the required total power of the light flux and the level of illumination of the area occupied by seedlings are determined. Based on these data, the design number of lamps or fixtures is calculated.
Mistakes of greenhouse lighting buyers
In a hurry to test the advantages of a new lighting system, gardeners make a typical mistake that can negate all the advantages of a purchase. This is the acquisition of Chinese non-name products. This usually happens spontaneously at numerous sales. As a rule, such goods do not withstand the specified parameters. This happens even with well-known manufacturers.
Purchase need With to carry out purposefully in stores specializing in the sale of just such products. Here you can get qualified advice on lighting plants and advice on choosing devices of the required power. In ordinary lighting stores, they may not know all the subtleties and sell the first equipment that comes across.
The main manufacturers of lamps for greenhouses
The main players in the LED lighting market are several companies.
Osram, a high-tech German lighting company, has been serving this market for a long time and not without success, having secured recognition in many countries. The quality of products is at a high level, regardless of the segment of products. The price varies depending on the class of equipment.
Devices at a low price are offered by the PRC manufacturer from China. Despite the country of origin, the products are of acceptable quality.
Led Grow Lights manufactures hydroponic lighting equipment and devices from the best American and Taiwanese components. The products are of high quality, power and, of course, rather big cost.
Uniel is an international manufacturer of LED equipment of Russian origin. Products and prices are middle class.
Today, with the widest choice of suppliers of LED phytolamps, you can choose a good set of additional illumination of flowers and seedlings. Properly selected light sources will allow you to get a good harvest in the fall.
Light is one of the necessary conditions for the normal growth of plants. And if there is enough sunlight in summer, then in winter, when the day is very short, plants experience a clear deficit of it. You can solve the problem of lack of light if you use special LED lamps for plants. This is true for those who grow seedlings, light-loving home flowers, or work in greenhouses year-round.
Why do plants need light?
Any student who is more or less familiar with the basics of botany knows the answer to this question. It's all about photosynthesis- a complex biochemical process that occurs in plant cells under the influence of sunlight. As a result, organic substances are synthesized from carbon dioxide and water. The leaves of plants contain special cells - chloroplasts, which contain chlorophyll. It is a pigment that directly absorbs light. It has a green color, which determines the color of the whole plant.
Making sure the importance of light for plants is very simple. It is enough just to remove any indoor flower in a dark room. After a short time, its leaves will first begin to turn white, then fall off. If you continue the experiment, the plant will simply die. It has been scientifically proven that photosynthesis takes place only with the participation of light. At night, this process does not take place, the plant only absorbs carbon dioxide.
Lamp instead of the sun
The use of electric lighting to replace sunlight has long been learned. This method is also used, for example, in greenhouses. However, how effectively can electric light replace sunlight? After all, for a full replacement, the light should be as close to natural as possible. Currently, fluorescent, halogen, incandescent, and more recently LED lamps are used to illuminate plants. It is LED lamps that are most qualitatively able to replace the lack of sunlight for plants.
To achieve a good effect, the spectrum of light emitted by the lamp must be as photoactive as possible, i.e. suitable for photosynthesis. LED lamps for plants (LED-phytolamps) fully meet this requirement. They are used both at home, for example, for seedlings on the windowsill, and on an industrial scale, illuminating huge greenhouses. Diode phytolamps have the following advantages over all others:
- low power consumption;
- operational safety;
- no flicker;
- long service life;
- resistance to high humidity;
- maximum phytoactive radiation in the absence of thermal radiation;
- easy adjustment of the spectrum and illumination level.
The biggest disadvantage of LED phytolamps is the high price. However, it is more than offset by all the advantages of these devices. Besides, you can do it yourself.
Homemade phytolamp
If you have time and desire, you can make this device with your own hands. This will require:
Before installation, the diodes must be checked for operability using a tester. If all is well, you can proceed with the installation. The working surface must be marked for mounting the LEDs, placing them at a distance of 7-8 mm from each other. It is advisable to mark the polarity with a red and blue marker so that you do not accidentally mix it up when soldering. Then the LEDs need to be glued to the concave side of the work surface using instant glue, alternating through three blue one red LED.
Then all the diodes must be soldered together in series, observing the polarity, with equal lengths of insulated wire. The ends of the chain are connected to the output terminals of the driver; a regular wire with a standard socket is used for the input. For soldering, a soldering iron with a power of 30-40 watts is quite enough, a more powerful one can burn an LED. It is necessary to ensure that the soldering points do not come into contact with the work surface. Just in case, under them, you can glue strips of electrical tape or adhesive tape.
It remains only to mount all structural elements on an aluminum profile using self-tapping screws. Such a lamp can be hung above the seedlings on the windowsill, and it will perform its function no worse than the purchased one.
Plants need light in addition to water and fertilizers to grow. But when grown indoors, especially in winter, the illumination is insufficient. Therefore, they need additional light. For this, phytolamps are used.
Plants need light of a certain spectrum to grow and live. Depending on the development of which parts is necessary, the spectral composition may change.
Signs of a lack of light in a plant
Effect of radiation on growth
Incandescent lamps are the least suitable for plants. In the spectrum of these lamps there is a lot of yellow light, which, like green, is poorly absorbed by plants. In addition, these lamps generate a lot of heat, which can burn the tops of flowers or seedlings.
Red light has a positive effect on the development of sprouts, flowering and the formation of ovaries. Purple and blue - promotes the development of the root system.
Variations in the light spectrum depending on the type of glow
Phytolamps use both colors. Depending on the tasks that the owner faces in different periods of plant growth, the required color ratio may vary.
Spectra of light and its characteristics
Ordinary sunlight has a continuous spectrum. In contrast, the white emitted by fluorescent and LED lamps consists of a mixture of different colors. They affect the plant in different ways:
- red - accelerates the development of sprouts from seeds, the formation of flowers and ovaries;
- orange - promotes fruit development;
- yellow and green - almost affect growth;
- purple and blue - stimulate the development of the root system and accelerate the onset of flowering;
- ultraviolet in small quantities prevents excessive growth, but in large doses causes burns.
Features of seedling lamps
In certain periods of seedling development, illumination of a different spectral composition is necessary. Fitolamps are made from LEDs of various colors, usually red and blue or special, two-color or multi-color, with white and ultraviolet LEDs.
Such lamps need a driver that allows you to adjust the color ratio and the overall brightness of the light.
Do-it-yourself LED phytolamp
Ready-made lamps and phytolamps are quite expensive. Their use is economically justified for commercial use. For the home, it is more profitable to make a phytolamp with your own hands.
It is made from the following elements:
- LEDs;
- base or radiator for their installation;
- driver for phytolamps or power supplies with dimmers;
- flexible copper connecting wires.
LED selection
LEDs in phytolamp
Four types of light sources can be used for phytolamps:
- LEDs specially designed for the manufacture of phytolamps. They are easy to install and have the ability to adjust the spectrum and radiation strength.
- Bright LEDs of the required colors, designed for installation on a radiator. You can use low-power diodes, but they will require a lot, which will increase the complexity of installation and design complexity.
- LED strips of red, with a wavelength of 630 nm, and blue, with a wavelength of 465 nm. This is close to the required 660 and 445.
- with RGB controller. If you do not connect green LEDs, then this is the easiest option to manufacture. The disadvantage is the loss of power and an increase in length - in the RGB tape, the ratio of red and blue LEDs is 1:1, and in phytolamps - 5:2, 7:3 or easier - 2:1.
Light consumption calculation
When illuminated with bulbs, plants need different amounts of light. It depends on the type, time of year, location of the window or greenhouse, and other factors.
The average power of phytolamps is 40 W / m2 on window sills, 80 W / m2 with fully artificial lighting and 150 W / m2 in grow boxes (closed boxes illuminated only by phyto lamps). More precisely, the calculation can be made by consulting with a specialist or by finding detailed instructions on specialized sites.
In any case, diode lamps should be evenly spaced over the entire surface of the beds or window sills. Distance to plants - 25 - 40 cm.
Driver calculation for LEDs
The brightness and ratio of colors in the backlight during different periods of plant development must be changed. Of course, you can choose some average value and use a conventional power supply, the voltage and power of which depend on the type of LEDs used.
Driver for LEDs
However, the ability to adjust each color individually has a positive effect on plants. This requires a driver with the appropriate capabilities. Instead of a special device, you can use adjustable power supplies, different for each color. The output voltage must match that required to power the LEDs, and the power must be chosen 20% more.
Since the ratio of red and blue colors is usually 2: 1, then the power of the power supplies should differ from each other in the same proportion.
Driver connection diagram for LED
The power of the driver is selected according to the total power of the LEDs.
The driver or dimmer can be replaced with a power supply. Each group of luminaires is individually equipped with its own switch.
Base frame for phytolamp
base for phytolamp
An old fluorescent lamp, a plastic box or other available materials can be used as a body for a phytolamp.
Frame for a phytolamp from an old lamp
Much depends on the installation location of the device - on the windowsill it is desirable that the light does not fall into the eyes of people in the room and on the street.
When using a radiator, avoid touching it.
This is especially important when connecting LEDs to a 220 V network.
The size of the LED-lamp should correspond to the size of the beds. For more efficient use of light, it is desirable to provide for the possibility of adjusting the phytolamp in height. You can install it on a bracket, stand, other holder, or hang it on a stand.
Plants under the lamp
Before installation, the LEDs are checked for operability. This must be done in order not to look for the cause of the lack of light after installation.
The LED is checked in the same way as a conventional diode - with a tester:
- when connecting the tester in one direction, it should show zero resistance, and in the opposite direction - infinite;
- if the diode is multicolor, then this procedure is repeated for each color separately.
Testing LEDs with a Tester
You can also test the LEDs for operability with a constant voltage source by connecting it through an additional resistor. Its value is calculated using Ohm's law or one of the online calculators.
The serviceability of the LED strip is checked by connecting the supply voltage to it.
We fix the LEDs on the profile
Bright high power LEDs are mounted on a radiator. It can be used as an aluminum plate or corner. Mounting method depends on the type:
- with holes for mounting - on the radiator using self-tapping screws or screws with washers and thermal paste;
- without holes - on heat-conducting glue;
- LED strips are glued with a sticky layer located on the reverse side, or with double-sided tape.
Connection diagrams
Installed LEDs are connected in series. Their number depends on the voltage of the power supply and the diodes themselves. In parallel with the LEDs, a current-limiting resistance is installed. Its value can be calculated using an online calculator.
Groups of several LEDs and a resistor, as well as segments of the LED strip, are connected in parallel.
Soldering
LEDs are connected by soldering. It is produced with a soldering iron with a power of up to 25 W, so as not to overheat the diode.
For soldering, tin-lead solder and rosin or other neutral flux are used.
Important! Acid cannot be used. This may cause a short circuit or destroy the wires.
Connectors can be used to connect the LED strip.
Correct use of LED lamp
LED lights do not heat plants, so they can be placed directly above them. The duration of illumination is determined by the time of year and the crop being illuminated. For example, lemons, other citrus fruits and orchids are illuminated from October to March.
Seedlings are illuminated depending on the stage of development - before picking, the blue-red ratio is 2: 1, after it - 1: 1, and within 2 - 3 days the brightness of the light is reduced.
Buy or make your own
The need to install a phytolamp for people caring for plants indoors is beyond doubt. The only question is whether to buy it or make it yourself.
A homemade lamp has both advantages and disadvantages.
homemade phytolamp
The main advantage is that it is much cheaper than purchased. You can buy LEDs and power supplies relatively inexpensively, especially if you order on Taobao or Aliexpress, use improvised materials for the case and radiators, and the plant owner will assemble the lamp with his own hands.
But besides the advantages, such a homemade product has disadvantages, the main of which is that its range differs from the ideal, especially if assembled from cheap components. In many commercial devices, it is much wider and consists not only of visible light, but also includes a small amount of ultraviolet.
Therefore, it is advisable to make a homemade phytolamp at home. With this approach, yield losses will be negligible.
A purchased lamp will pay off only with commercial use and large volumes of production.