CN111280040B

CN111280040B - Green onion cultivation method under LED light modulation control

Info

Publication number: CN111280040B
Application number: CN202010196372.1A
Authority: CN
Inventors: 徐坤; 高松; 曹逼力; 刘学娜; 董宜科
Original assignee: Shandong Agricultural University
Current assignee: Shandong Agricultural University
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2021-12-03
Anticipated expiration: 2040-03-19
Also published as: CN111280040A

Abstract

The invention discloses a green onion cultivation method under LED light control, which comprises the following steps: (1) after the green Chinese onion seeds germinate, carrying out seedling culture until seedlings with 2-3 true leaves are cultured; (2) transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, and irradiating by using an LED lamp light set in the cultivation process to maintain the light intensity of the plant canopy at (301.6 +/-12.7) mu mol.m^‑2·s^‑1The illumination time is 12-14 h/d; the LED light group comprises a blue LED and a white LED. The green onion cultivated by the method has high photosynthetic efficiency and excellent product quality, and the leaf pigment, the photosynthetic efficiency, the stomatal conductance and the light energy utilization rate of the green onion are all obviously increased.

Description

Green onion cultivation method under LED light modulation control

Technical Field

The invention relates to the technical field of crop cultivation, in particular to a green onion cultivation method under LED light control.

Background

In recent years, plant factories with full artificial light sources become new intelligent equipment in facility agriculture, particularly in facility vegetable production, the main principle is to provide optimal illumination conditions for crop growth according to the light-requiring characteristics of crops, and the plant factories have the advantages of highly controllable production environment, continuous and stable production in the year round, safe and reliable product quality and the like. The light is not only an energy source for plant photosynthesis, but also an important signal source in the growth and development process of plants, and the light intensity, the light quality, the light period and the like can regulate the growth and development of plants. Researches show that compared with white light, the blue light can improve the content of photosynthetic pigments in lettuce leaves and promote the opening of pores in cucumber leaves; and the red light can improve the photosynthetic pigment content and photosynthetic rate of the leaf lettuce. In terms of quality, the content of free amino acids, soluble proteins and anthocyanin in eggplant pulp and eggplant peel treated by blue light is obviously higher than that treated by red light. The Vc content of the edible part of the cabbage mustard treated by the white light is obviously higher than that of the edible part of the cabbage mustard treated by the blue light and the red light, and the total content of phenols and anthocyanins of the edible part of the cabbage mustard is improved by the blue light treatment; however, the soluble solid and Vc content in strawberry fruits are higher by red light treatment, and the content of titratable acid and soluble protein in fruits can be improved by blue light treatment. The results show that the quality of different crops and the response of nutrient to the light quality are obviously different.

Compared with the traditional agriculture, the plant factory has higher benefit, and mainly cultivates vegetables with shorter production period. With the change of the consumption market in recent years, the white cultivation of the Chinese onions (Allium fistulosum L.) is gradually changed from the traditional Chinese onion white cultivation of one crop in a year to the cultivation of fresh green leaves (green onions) of more crops in a year, the green onions do not need to be cultivated with earth, the growth speed is high, the planting density is high, the output benefit of unit area is high, and good conditions are created for the factory production of artificial light source plants.

The application of the LED as an artificial light source or a supplementary light source in the field of plant cultivation has become a focus of attention of researchers at home and abroad. Researches find that the single or combined LED light quality controls the morphogenesis and photosynthesis of vegetables such as spinach, radish, lettuce, beet, pepper, perilla and the like to generate different effects. However, the LED light environment regulation and control technology and mechanism in the field of vegetable facility cultivation in China are still in the development stage at present, and no report is found on the green onion cultivation method under the LED light regulation and control.

Disclosure of Invention

Aiming at the prior art, the invention aims to provide a green onion cultivation method under LED light control, researches the changes of growth, quality and photosynthetic property of green onions under different light quality conditions, and provides a basis for green onion production in an LED plant factory.

In order to achieve the purpose, the invention adopts the following technical scheme:

a green onion cultivation method under LED light control comprises the following steps:

(1) after the green Chinese onion seeds germinate, carrying out seedling culture until seedlings with 2-3 true leaves are cultured;

(2) transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, and irradiating by using an LED lamp light set in the cultivation process to ensure thatThe light intensity of the plant canopy is maintained at (301.6 +/-12.7) mu mol.m^-2·s^-1The illumination time is 12-14 h/d; the LED light group comprises a blue LED and a white LED.

Preferably, in the step (1), the method for germinating the scallion seeds comprises the following steps: sowing the seeds of the green Chinese onions into a hole tray filled with a seedling culture medium, sowing 4 seeds in each hole, sowing the seeds with the depth of 0.5cm, compacting after sowing, covering a mulching film after watering, preserving heat and moisture, removing the mulching film in time when the seeds germinate, irrigating nutrient solution once every 3d, reserving 2-3 plants in each hole through thinning, and reserving 1 plant in each hole when the seedlings are 4-5cm high.

More preferably, the seedling raising substrate consists of grass carbon, perlite and vermiculite according to the volume ratio of 6:3: 1.

More preferably, the nutrient solution is 1/2Hoagland nutrient solution.

Preferably, in the step (1), the seedling raising conditions are as follows: the illumination intensity is 200-^-2·s^-1The illumination time is 12-14h/d, the temperature is 24-26 ℃, and the relative humidity is 65-70%.

The seedling culture is an important link of vegetable production, and as the morphogenesis of seedlings is an irreversible process, the robustness of the cultured seedlings directly influences the growth and development of plants and is closely related to the yield and quality of crops. By adopting the seedling culture condition of the invention, the cultured green Chinese onion seedlings grow robustly and are beneficial to improving the yield and quality of green Chinese onions.

Preferably, in the step (2), the number ratio of the blue LEDs to the white LEDs is 1: 3.

Light is used as an energy source not only to control photosynthesis, but also as a trigger signal to affect other aspects of plant growth and development. Different light intensities and light qualities can lead to distinct growth patterns, and different plant species respond differently to light. The LED is a novel LED, has the advantages of small volume, light weight, long service life, special wavelength, high light efficiency, low energy consumption, safety, difficult color fading and the like, and is gradually applied to plant cultivation in controllable facility environments. The light supplementing effect of the plant by selecting the proper LED light source can be good. But the quality of different crops and the response of nutrient pair light quality are obviously different. The research of the invention finds that the blue light LED and the white light LED in a specific proportion are combined, contain different light quality components, are complementary with each other, and have remarkable promotion effect on the pigment content of the green onion leaves, the photosynthetic efficiency, the air pore conductivity and the light energy utilization rate.

Preferably, in the step (2), the culture medium placed on the cultivation frame is grass peat, the organic matter content of the grass peat is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5. The turf used in the invention is soft in texture, easy to break, brown or black in color, flammable and breathable. Researches show that the culture medium is particularly suitable for industrial production of the green onions, has good holding performance on nutrient solution and certain antibacterial activity, and is beneficial to the rapid growth of the green onions.

Preferably, in the step (2), the planting distance of the seedlings is 2-3cm, and the row spacing is 18-20 cm. Compared with the traditional welsh onion white cultivation, the welsh onion cultivation method disclosed by the invention has the advantages that the cultivation density is greatly improved, and the yield of the welsh onion is increased.

Preferably, in the step (2), the temperature conditions for the cultivation are: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; the relative humidity of air is (65.2 +/-4.5)%.

Preferably, in step (2), the plant factory comprises: the cultivation room is internally provided with a plurality of layers of cultivation frames, the top of each layer of the cultivation frame is provided with an LED light source, and the LED light sources are connected with a light intensity regulator;

further comprising: the air inlet and the air outlet of the central air conditioner are respectively communicated with the cultivation chamber and the air chamber, the air blowing port of the fresh air system is arranged in the air chamber, and the cultivation chamber is provided with an air outlet communicated with the outside.

More preferably, a humidifying pipeline is arranged in the air chamber, and a humidifying opening is formed in the humidifying pipeline. The humidity in the air chamber can be adjusted through the arranged humidifying pipeline and the humidifying port, so that the humidity in the cultivation chamber can be adjusted.

The invention has the beneficial effects that:

the green onion cultivated by the method has high photosynthetic efficiency and excellent product quality, and the leaf pigment, the photosynthetic efficiency, the stomatal conductance and the light energy utilization rate of the green onion are all obviously increased.

Drawings

FIG. 1: the invention discloses a schematic structure diagram of a plant factory for green onion cultivation; the cultivation device comprises a cultivation room 1, a cultivation room 2, an air room 3, a communication port 4, a cultivation frame 5, an LED light source 6, a light intensity regulator 7, an automatic time control switch 8, a central air conditioner 9, a fresh air system 10, a humidification pipeline 11 and an air filtering device.

FIG. 2: spectral characteristics of different treatments.

FIG. 3: influence of different lights on the pigment content of green onion leaves.

FIG. 4: influence of different light on the photosynthesis rate and the dynamic change of the porosity conductivity of the green onion leaves.

FIG. 5: different photopic pairs of green onion leaves Pn-PFD (left) and Pn-CO₂(Right).

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

As described in the background section, the evolution of Allium fistulosum (L.) from traditional one-crop-a-year-long onion white cultivation gradually shifted to more than one-year-old green leaf (green onion) cultivation. The application of the LED as an artificial light source or a supplementary light source in the field of plant cultivation has become a focus of attention of researchers at home and abroad. The single or combined LED light quality has different regulation and control effects on the morphogenesis and photosynthesis of different crops. For the cultivation of green onions, no report on industrial production of green onions through LED light control is available at present.

Based on the method, the green onion cultivation method under the LED light control is researched. In order to examine the changes of the growth, the quality and the photosynthetic property of the green onions under different light quality conditions, the invention adopts a cleavage zone test method. The split zone test design is a classical design method, and the statistical result can analyze the difference between the processing of the main zone and the processing of the auxiliary zone respectively and also can determine whether the interaction exists between the main zone and the auxiliary zone. This paper uses the split zone experimental design, with the DPS software for multiple comparative analyses (Thangjiu. DPS data processing System (2 nd edition); Beijing: scientific Press, 2010.02). The main zone is a green Chinese onion variety, namely 'dun' green Chinese onion and 'Tianguang' green Chinese onion; the secondary region is culture room light quality, which is respectively white light (W), blue light (B), green light (G), yellow light (Y) and red light (R). "the P value in the statistical table reflects whether the interaction effect between varieties with the same light quality, or between varieties with the same light quality, and between varieties and light quality is significant, P <0.05 indicates that the difference reaches a significant level, and P > 0.05 indicates that the difference reaches a significant level.

The specific test procedure is as follows:

1.1 experimental design:

the scallion varieties adopted in the test are 'dun' scallion and 'Tianguang' scallion, and the test is carried out in 2019 in a light quality culture room of the institute of horticultural science and engineering of Shandong agricultural university. Adopting a splitting area design, wherein the main area is a green Chinese onion variety, namely a 'nutlet' green Chinese onion and a 'daybreak' green Chinese onion; the secondary regions are culture chamber light qualities of white light (W), blue light (B), green light (G), yellow light (Y) and red light (R), and the spectral characteristics are shown in FIG. 2. Adopting a tray with 72 holes for seedling culture, wherein the culture medium is turf: perlite: vermiculite (6: 3: 1). After sowing, the seedlings are watered once every 3 days with 1/2Hoagland nutrient solution, 1 seedling is left in each hole when the height of the seedling is about 5cm, the height of the seedling is about 15cm, and the seedling is cultured under LED dimming plant lamps (produced by Huizhou Kongshi Co., Ltd.) with different light qualities when the seedling has 2-3 main leaves. Different treatments are separated by black and white double-sided shading cloth.

By adjusting the light intensity of the LED light source, the light intensity of each plant canopy to be treated is maintained at (301.6 +/-12.7) mu mol.m^-2·s^-1The day/night temperature was controlled at 25 deg.C/18 deg.C, the air relative humidity was (65.2 + -4.5)%, and the illumination time was 12 h/d. The experiment was performed in 3 replicates, one replicate for each 20 plants, and 60 plants per treatment. The experimental results are the average of two independent experiments.

1.2 test indexes and methods:

UNISPECCDC manufactured by PP-SYSTEMS of UK^TMThe spectrum analyzer measures the spectral characteristics of the LED light source, the measuring wave band is 300-1100nm, and the scanning wavelength interval is 3.3 nm.

Sampling at test treatment time of 0, 10, 20, 30, and 40d, respectively, measuring photosynthetic parameters of 2 nd functional leaf on the plant with CIRAS-3 type photosynthetic apparatus produced by PP-SYSTEMS of UK, and controlling internal light source and CO₂Determination of the concentration Pn-PFD response Curve and Pn-CO₂A response curve. The chlorophyll content of the leaves is measured by a 95% ethanol extraction method. When the plants are harvested, randomly selecting 5 plants per tray, measuring the growth amount and the quality of an edible part of the plants, measuring the content of soluble sugar by an anthrone method, measuring the content of cellulose by a concentrated sulfuric acid hydrolysis sugar determination method, measuring the content of pyruvic acid by a 2, 4-dinitrophenylhydrazine chromogenic method, measuring the content of soluble protein by a Coomassie brilliant blue method, and measuring the content of free amino acid by a ninhydrin solution chromogenic method.

1.3 data processing

The test data are processed, plotted and statistically analyzed by Excel 2016, DPS software and a photosynthetic light reaction mechanism model, and the significance of the difference (P <0.05) is tested by a Duncan new double-pole difference method.

2. Results and analysis

2.1 Effect of different light quality treatment conditions on the growth of Green onion plants

As can be seen from Table 1, the plant height, pseudostem thickness, fresh leaf weight, fresh pseudostem weight, fresh root weight and individual plant weight average of the green onions were higher with white light treatment, followed by blue light treatment, but the pseudostem length was higher with blue light treatment, and there was no significant difference in the number of leaves between the two. For example, the plant height of the white-light treated green onion is increased by 4.36 percent compared with that of the blue light, while the plant heights of the red-light treated green onion, the green-light treated green onion and the yellow-light treated green onion are respectively reduced by 8.03 percent, 13.43 percent and 24.43 percent compared with the blue light, the weight of the white-light treated green onion is 26.06g, and the plant heights of the blue light, the red light, the green light and the yellow light are respectively reduced by 7.06 percent, 16.35 percent, 25.44 percent and 36.61 percent compared with the white light. The two green onion varieties have no obvious difference in stem length and leaf fresh weight, and the stem thickness, stem fresh weight, root fresh weight and single plant weight average show that 'nutting' is superior to 'dayang' green onion.

Table 1: influence on growth amount of green onion after 30 days of treatment with different light qualities

Note: the P value in the statistical table reflects the difference between varieties with the same light quality or between light qualities with the same varieties and whether the interaction effect of the varieties and the light qualities is remarkable or not, P <0.05 indicates that the difference reaches a remarkable level, and P > 0.05 indicates that the difference does not reach a remarkable level. The same applies below.

2.2 Effect of different light quality treatments on the quality of Green onions

Table 2 shows that the quality of the green onions treated by white light is remarkably higher than that of other monochromatic lights, the soluble sugar content of the green onions treated by blue light, red light, green light and yellow light is reduced by 11.67%, 24.44%, 36.67% and 58.33% respectively compared with that of the green light treatment, and the pyruvic acid content of the green onions treated by blue light, red light, green light and yellow light is reduced by 8.65%, 20.19%, 56.73% and 44.23% respectively compared with that of the green light treatment. The two green Chinese onion varieties have obvious difference in other quality indexes except soluble protein, the content of soluble sugar is obviously higher than that of 'nutting' green Chinese onion in terms of 'daytimes', and other indexes are higher in terms of 'nutting' green Chinese onion.

TABLE 2 influence of different light qualities on the quality of green onions

2.3 Effect of different light quality treatments on the pigment content of the leaves of green onion

As can be seen from fig. 3, at 30d treatment, the chlorophyll content of the 'cumulus' green onion leaves was significantly higher than that of the 'daybreak' green onions. The pigment content is higher by white light treatment, the blue light, the red light, the green light and the yellow light are sequentially reduced, for example, when the leaves are treated for 30 days, the chlorophyll content of the leaves treated by the white light reaches 1.58mg/g, and the blue light, the red light, the green light and the yellow light are respectively reduced by 9.49%, 14.56%, 22.78% and 30.38% compared with the white light treatment. The change trend of the carotenoid content is basically consistent with that of chlorophyll.

2.4 Effect of different light quality treatments on the photosynthetic parameters of the leaves of the Green onion

FIG. 4 shows that the photosynthetic rate of the green onion leaves is in an increasing trend with the increase of the treatment time, the white light treatment is higher, and the blue light, the red light, the green light and the yellow light are reduced in sequence. The net photosynthetic rate of the white-light treated leaves was 7.63. mu. mol. m when treated for 40 days^-2·s^-1Blue, red, green and yellow treatments were reduced by 10.22%, 19.40% and 28.18% and 37.35%, respectively, compared to the white treatment. Compared with two allium fistulosum varieties, the Pn of the 'nutlet' leaf is obviously higher than that of the 'Tianguang' allium fistulosum, but the Gs of the two allium fistulosum are not obviously different. The Gs of the green onion leaves treated by different light qualities are obviously different, the white light treatment is higher, the blue light treatment, the red light treatment, the green light treatment and the yellow light treatment are sequentially reduced, and if the green onion leaves are treated for 40 days, the porosity conductance of the white light treated leaves is 441.50 mmol.m^-2·s^-1Blue, green, yellow and red treatments were reduced by 2.76%, 7.29%, 10.19% and 5.02% respectively compared to white light.

2.5 different light qualities on the green onion leaves Pn-PFD and Pn-CO₂Influence of response characteristics

As can be seen from FIG. 5, the Pn-PFD and Pn-CO of the leaves of two species of green onion₂The change trends of the response curves are basically consistent, and the difference between the response curves and the response curves is small; the different light quality treatments have obvious difference, the white light treatment Pn is higher, and the blue light, the red light, the green light and the yellow light are reduced in sequence.

Photosynthetic parameters obtained through analysis of a photosynthetic light reaction mechanism model are shown in table 3, and it can be seen that the green onion leaves AQY are higher and are 0.0542 under white light treatment, and blue light, red light, green light and yellow light are sequentially reduced, which indicates that the green onion is higher under monochromatic light treatment with blue light AQY, and is inferior to red light and green light and lower in yellow light; the light saturation photosynthetic rate (Pmax) is higher with white light treatment, and reaches 13.29 mu mol.m^-2·s^-1Blue, red, green and yellow treatments were reduced by 5.12%, 8.65%, 13.47% and 17.68%, respectively, compared to white light. The green onion LSP has higher white light, the other monochromatic light treatment has no obvious difference, the LCP has higher yellow light, the green light and the red light are inferior, and the blue light and the white light are lower, which reflects the white light,The blue light energy utilization capacity is strong. The two Allium fistulosum species have significant differences in other parameters except AQY, with Pmax being significantly higher with 'cumulus' than with 'daylight' and LSP and LCP being higher with 'daylight' than with 'daylight' Allium fistulosum.

TABLE 3 Effect of different light quality treatments on the photo-physiological characteristic parameters of the leaves of green onion

Table 3 also shows that the green onion leaf CE treatment was higher with white light up to 0.0780, while the blue, red, green and yellow treatments were reduced by 7.69%, 12.44%, 17.95% and 22.18% respectively from the white light treatment. The CCP of green onion is low in white light treatment, and is 57.35 μ l.L^-1Blue, red, green and yellow light are increased by 13.38%, 30.60%, 39.98% and 53.60% respectively over white light; the CSP of scallion is significantly lower in white, blue than other monochromatic lights, while red, green and yellow treatments are not significantly different. The maximum regeneration rate of RuBP is higher than that of white light and blue light, and is 38.98 and 37.23 mu mol.m respectively^-2·s^-1The red light, green light and yellow light are respectively 36.41, 34.89 and 32.98 mu mol.m^-2·s^-1Indicating that the green onion leaves are fixed with CO under the blue light treatment₂Has stronger capability. There was also a significant difference in the photosynthetic parameters associated with the two Allium fistulosum species, with the maximum rates of CE and RuBP regeneration being significantly higher with ' cumulus ' than with ' daylight ' and with CSP and CCP being higher with ' daylight ' than with ' welsh onion.

In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions of the present application will be described in detail below with reference to specific embodiments.

The test materials used in the examples and comparative examples of the present invention are conventional in the art and are commercially available.

The scallion variety used in the examples and comparative examples of the present invention is "Tianguang" scallion.

Example 1: green onion cultivation under LED light modulation control

(1) Sowing seeds of the green Chinese onions in a plug tray filled with a seedling culture medium, and sowing and culturing seedlings by using a 72-hole plug tray medium, wherein the seedling culture medium consists of grass carbon, perlite and vermiculite according to a volume ratio of 6:3: 1; 4 seeds are sowed in each hole, the sowing depth is 0.5cm, the seeds are compacted after sowing, mulching films are covered after the seeds are watered thoroughly, the temperature and the moisture are preserved, and the mulching films are removed in time when the seeds germinate. After the green Chinese onion seeds germinate, seedling culture is carried out, wherein the seedling culture conditions are as follows: irrigating once every 3 days with nutrient solution, and reserving 2-3 plants per hole through thinning with illumination intensity of 220 μmol · m^-2·s^-1The illumination time is 14h/d, the temperature is 24 ℃, the relative humidity is 65-70%, and the seedlings with 2-3 true leaves and the height of about 15cm are cultured.

(2) Transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, wherein a culture medium placed on the cultivation frame is turf, the organic matter content of the turf is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5. The planting distance of the seedlings is 3cm, and the row spacing is 20 cm; irradiating with LED lamp to maintain the light intensity of plant canopy at (301.6 + -12.7) μmol · m^-2·s^-1The illumination time is 12 h/d; the LED lamplight group comprises a blue LED and a white LED, and the number ratio of the blue LED to the white LED is 1: 3. The temperature conditions for the culture were: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; the relative humidity of air is (65.2 +/-4.5)%. The Hoagland nutrient solution is irrigated once every 10 days, and the culture medium is irrigated thoroughly.

The plant factory used for cultivation may be a plant factory existing in the prior art, and a schematic configuration of the plant factory used in this embodiment is shown in fig. 1. Comprises a cultivation chamber 1 and an air chamber 2 communicated with the cultivation chamber 1. The air chamber 2 is arranged at the top of the cultivation room 1, the air chamber is arranged at the inner side of the top of the cultivation room, a plurality of communication ports 3 are arranged at the bottom of the air chamber 2, and the communication ports 3 are distributed and arranged, so that the gas in the air chamber 2 is dispersed and blown into all places of the cultivation room 1. Cultivation room 1 is equipped with three-layer cultivation frame 4 in, and cultivation frame 4 all cultivates the green Chinese onion seedling on every layer, and the top on every layer of cultivation frame 4 all is equipped with the LED light source 5 that is located green Chinese onion seedling top, 5 electric connection of LED light source has light intensity regulator 6, each layer of cultivation frame 4 is equipped with light intensity regulator 6 respectively, and light intensity regulator 6 on every layer controls the illumination intensity of the LED light source 5 on corresponding layer alone, sets up illumination intensity according to the green Chinese onion growth habit through light intensity regulator. The LED light source 5 is electrically connected with an automatic time control switch 7, and one automatic time control switch 7 is arranged and can control the switches of all the LED light sources 5.

Further comprising: central air conditioning 8 and new trend system 9, central air conditioning 8 set up the bottom surface in air chamber 2 inside, and central air conditioning 8's air inlet and gas outlet communicate cultivation room 1 and air chamber 2 respectively, be equipped with air filter 11 on central air conditioning 8's the air inlet for filter the air that gets into central air conditioning 8. The temperature sensing means of the central air conditioner 8 is provided in the cultivation room 1 so as to precisely control the temperature of the air inside the cultivation room 1. The air blowing port of the fresh air system 9 is arranged in the air chamber 2, external fresh air can be blown into the air chamber 2, an air exhaust port communicated with the outside is arranged on the cultivation chamber 1, and the air exhaust port is arranged on the side face of the cultivation chamber 1. Fresh air is blown into the air chamber 2 by the fresh air system, the fresh air and the air blown out by the central air conditioner 8 are mixed and then enter the cultivation chamber 1 through the communication port 3, one part of the original air in the cultivation chamber 1 enters the air chamber 2 through the central air conditioner 8, and the other part of the original air is discharged through the exhaust port, so that the air in the cultivation chamber 1 is updated.

Still be equipped with humidification pipeline 10 in the air chamber 2, it has the humidification mouth to open on the humidification pipeline 10, humidification pipeline 10 intercommunication humidifier can adjust the air humidity in the air chamber 2 to adjust the humidity in the cultivation room 1.

Comparative example 1: green onion cultivation under LED light modulation control

(1) Sowing seeds of the green Chinese onions in a plug tray filled with a seedling culture medium, and sowing and culturing seedlings by using a 72-hole plug tray medium, wherein the seedling culture medium consists of grass carbon, perlite and vermiculite according to a volume ratio of 6:3: 1; 4 seeds are sowed in each hole, the sowing depth is 0.5cm, the seeds are compacted after sowing, mulching films are covered after the seeds are watered thoroughly, the temperature and the moisture are preserved, and the mulching films are removed in time when the seeds germinate. After the green Chinese onion seeds germinate, seedling culture is carried out, wherein the seedling culture conditions are as follows: irrigating once every 3 days with nutrient solution, and reserving 2-3 plants per hole through thinning with illumination intensity of 240 μmol · m^-2·s^-1Light ofCulturing at 24 deg.C and 65-70% relative humidity for 12h/d until the height of seedling is about 15cm and the seedling has 2-3 true leaves.

(2) Transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, wherein a culture medium placed on the cultivation frame is turf, the organic matter content of the turf is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5. The planting distance of the seedlings is 3cm, and the row spacing is 20 cm; irradiating with LED lamp to maintain the light intensity of plant canopy at 340.5 + -14.2 μmol · m^-2·s^-1The illumination time is 12 h/d; the LED light group is a blue LED. The temperature conditions for the culture were: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; the relative humidity of air is (65.2 +/-4.5)%. The Hoagland nutrient solution is irrigated once every 10 days, and the culture medium is irrigated thoroughly.

Comparative example 2: green onion cultivation under LED light modulation control

(1) Sowing seeds of the green Chinese onions in a plug tray filled with a seedling substrate, and sowing and seedling by using a 72-hole plug tray substrate, wherein the seedling substrate consists of grass carbon and vermiculite according to a volume ratio of 9: 1; 4 seeds are sowed in each hole, the sowing depth is 0.5cm, the seeds are compacted after sowing, mulching films are covered after the seeds are watered thoroughly, the temperature and the moisture are preserved, and the mulching films are removed in time when the seeds germinate. After the green Chinese onion seeds germinate, seedling culture is carried out, wherein the seedling culture conditions are as follows: irrigating once every 3 days with nutrient solution, and reserving 2-3 plants per hole through thinning with illumination intensity of 230 μmol · m^-2·s^-1The illumination time is 14h/d, the temperature is 24 ℃, the relative humidity is 65-70%, and the seedlings with 2-3 true leaves and the height of about 15cm are cultured.

(2) Transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, wherein a culture medium placed on the cultivation frame is turf, the organic matter content of the turf is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5. The planting distance of the seedlings is 3cm, and the row spacing is 20 cm; irradiating with LED lamp to maintain the light intensity of plant canopy at (301.6 + -12.7) μmol · m^-2·s^-1The illumination time is 12 h/d; the LED light group is a white LED. The temperature conditions for the culture were: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; relative humidity of air is(65.2. + -. 4.5)%. The Hoagland nutrient solution is irrigated once every 10 days, and the culture medium is irrigated thoroughly.

Comparative example 3: green onion cultivation under LED light modulation control

(1) Sowing seeds of the green Chinese onions in a plug tray filled with a seedling culture medium, and sowing and culturing seedlings by using a 72-hole plug tray medium, wherein the seedling culture medium consists of grass carbon, perlite and vermiculite according to a volume ratio of 6:3: 1; 4 seeds are sowed in each hole, the sowing depth is 0.5cm, the seeds are compacted after sowing, mulching films are covered after the seeds are watered thoroughly, the temperature and the moisture are preserved, and the mulching films are removed in time when the seeds germinate. After the green Chinese onion seeds germinate, seedling culture is carried out, wherein the seedling culture conditions are as follows: irrigating once every 3 days with nutrient solution, and reserving 2-3 plants per hole through thinning with illumination intensity of 230 μmol · m^-2·s^-1The illumination time is 14h/d, the temperature is 24 ℃, the relative humidity is 65-70%, and the seedlings with 2-3 true leaves and the height of about 15cm are cultured.

(2) Transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, wherein a culture medium placed on the cultivation frame is turf, the organic matter content of the turf is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5. The planting distance of the seedlings is 3cm, and the row spacing is 20 cm; irradiating with LED lamp to maintain the light intensity of plant canopy at (301.6 + -12.7) μmol · m^-2·s^-1The illumination time is 12 h/d; the LED lamplight group comprises a blue LED and a white LED, and the number ratio of the blue LED to the white LED is 1: 1. The temperature conditions for the culture were: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; the relative humidity of air is (65.2 +/-4.5)%. The Hoagland nutrient solution is irrigated once every 10 days, and the culture medium is irrigated thoroughly.

Harvesting green onions after culturing for 70 days according to the methods of example 1 and comparative examples 1 to 3, respectively, wherein the plant factories used in comparative examples 1 to 3 are the same as those in example 1. The yield of green onions of each example and comparative example was counted and the quality of green onions was examined and the results are shown in table 4 (yield in table 4 is converted to acre yield) and table 5, respectively.

Table 4: comparison of Green onion yields

Group of	Green onion yield (kg)
		Example 1	3277.64a
Comparative example 1	2638.13d
		Comparative example 2	2876.94c
Comparative example 3	3146.62b

Table 5: comparison of Green onion quality

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A green onion cultivation method under LED light control is characterized by comprising the following steps:

(1) sowing seeds of the green Chinese onions in a plug tray filled with a seedling culture medium, and sowing and culturing seedlings by using a 72-hole plug tray medium, wherein the seedling culture medium consists of grass carbon, perlite and vermiculite according to a volume ratio of 6:3: 1; each acupoint4 seeds are sown, the sowing depth is 0.5cm, the seeds are compacted after sowing, mulching films are covered after the seeds are watered thoroughly, the temperature and the moisture are preserved, and the mulching films are removed in time when the seeds germinate; after the green Chinese onion seeds germinate, seedling culture is carried out, wherein the seedling culture conditions are as follows: irrigating once every 3 days with nutrient solution, and reserving 2-3 plants per hole through thinning with illumination intensity of 220 μmol · m^-2·s^-1The illumination time is 14h/d, the temperature is 24 ℃, the relative humidity is 65-70%, and the seedlings with 2-3 true leaves and the height of about 15cm are cultured;

(2) transplanting the seedlings bred in the step (1) to a cultivation frame of a plant factory for cultivation, wherein a culture medium placed on the cultivation frame is turf, the organic matter content of the turf is more than 30%, the specific gravity is 0.7-1.05, and the pH value is 5.5-6.5; the planting distance of the seedlings is 3cm, and the row spacing is 20 cm; irradiating with LED lamp to maintain the light intensity of plant canopy at (301.6 + -12.7) μmol · m^-2·s^-1The illumination time is 12 h/d; the LED light group comprises a blue LED and a white LED, and the number ratio of the blue LED to the white LED is 1: 3; the temperature conditions for the culture were: the day/night temperature was controlled at 25 ℃/18 ℃ respectively; the relative humidity of air is (65.2 +/-4.5)%; irrigating the Hoagland nutrient solution once every 10 days, and completely irrigating the culture medium;

the plant factory used for cultivation comprises a cultivation chamber and an air chamber communicated with the cultivation chamber; the air chamber is arranged at the top of the cultivation chamber, the air chamber is arranged on the inner side of the top of the cultivation chamber, a plurality of communication ports are formed in the bottom of the air chamber, and the communication ports are distributed so that the gas in the air chamber can be dispersed and blown into all parts of the cultivation chamber; the cultivation room is internally provided with three layers of cultivation frames, each layer of the cultivation frames is cultivated with green Chinese onion seedlings, the top of each layer of the cultivation frames is provided with an LED light source positioned above the green Chinese onion seedlings, the LED light source is electrically connected with a light intensity regulator, each layer of the cultivation frames is respectively provided with the light intensity regulator, the light intensity regulator of each layer independently controls the illumination intensity of the LED light source of the corresponding layer, and the illumination intensity is set according to the growth habit of the green Chinese onion through the light intensity regulator; the LED light sources are electrically connected with an automatic time control switch, and one automatic time control switch is arranged and can control the switches of all the LED light sources; further comprising: the central air conditioner is arranged on the bottom surface inside the air chamber, an air inlet and an air outlet of the central air conditioner are respectively communicated with the cultivation chamber and the air chamber, and an air filtering device is arranged on the air inlet of the central air conditioner and used for filtering air entering the central air conditioner; the temperature sensing device of the central air conditioner is arranged in the cultivation room, so that the air temperature in the cultivation room is accurately controlled; an air blowing port of the fresh air system is arranged in the air chamber and can blow external fresh air into the air chamber, an air exhaust port communicated with the outside is arranged on the cultivation chamber, and the air exhaust port is arranged on the side face of the cultivation chamber; the fresh air system blows fresh air into the air chamber, the fresh air and the air blown out by the central air conditioner are mixed and then enter the cultivation chamber through the communication port, one part of the original air in the cultivation chamber enters the air chamber through the central air conditioner, the other part of the original air is exhausted through the exhaust port, and therefore the air in the cultivation chamber is updated,

the air chamber is also internally provided with a humidifying pipeline, a humidifying opening is formed in the humidifying pipeline, the humidifying pipeline is communicated with a humidifier to adjust the air humidity in the air chamber, and therefore the humidity in the cultivation chamber is adjusted.