A method for increasing vegetable yield in a plant factory

Abstract

This invention discloses a method for increasing vegetable yield in plant factories, belonging to the field of plant factory production technology. The method includes the following steps: transplanting vegetable seedlings onto planting boards for hydroponic cultivation in a nutrient solution, and applying continuous LED red and blue light and far-red light to increase vegetable yield per unit area; the nutrient solution includes 1 / 2 Hoagland nutrient solution, polyglutamic acid, and seaweed fertilizer; during cultivation, the planting density of vegetable seedlings is 50-69 plants / m². 2 The intensity of the far-red light is 30–50 μmol / (m²). 2 This invention utilizes far-red light to regulate plant shape and increases planting density, which can improve the light energy utilization rate of vegetables. At the same time, it increases the amount of organic carbon that plants can absorb and utilize in the hydroponic nutrient solution, thereby increasing the yield of vegetables per unit area. This helps to promote plant factory production technology, reduce production costs, and achieve energy conservation and efficiency improvement.

Description

Technical Field

[0001] This invention belongs to the field of plant factory production technology, and more specifically relates to a method for increasing the yield of vegetables in plant factories. Background Technology

[0002] Currently, LEDs are the primary artificial light source in plant factories. While there is considerable research on the effects of red and blue light on vegetable growth and quality, and although LEDs have higher luminous efficacy than other light sources, they still face the challenge of high energy consumption per unit yield of vegetables. Current solutions mainly focus on optimizing the light formula (light quality, light intensity, and illumination duration), but this is limited by the inherent luminous efficacy of LED lamps. Improving light absorption and utilization by plants may be another effective approach. At appropriate planting densities, crop leaves can fully absorb light energy, improving light capture and utilization efficiency and promoting the synthesis and accumulation of photosynthetic products. However, overly dense cultivation can intensify competition for water and nutrients, affecting normal crop growth and development. Therefore, plant factories need to comprehensively consider crop growth characteristics and photosynthetic efficiency, achieving optimal crop production through technological innovation.

[0003] A plant factory is a relatively enclosed environment where crops continuously absorb and release CO2. During photoperiod, indoor green plants undergo vigorous photosynthesis, causing a sharp drop in CO2 concentration; maintaining normal plant growth often requires timely CO2 replenishment. Currently, most large-scale plant factories use boilers burning natural gas to generate CO2 to supplement the plants' CO2 needs. However, this method produces a certain amount of harmful gases, causing irreversible damage to normal plant growth, while adding air purification facilities significantly increases costs. Alternatively, multiple CO2 sensors installed inside the plant factory are connected to the factory's air conditioning vents, which are then connected to a large outdoor CO2 tank. The CO2 is mixed with air and then delivered to the workshop through a fresh air system, artificially supplying CO2 to fertilize the plants. While this method avoids the introduction of other harmful gases, it is costly and requires supporting hardware and software equipment, monitoring, and operating systems, making operation and management complex.

[0004] Therefore, it is of great significance to develop a simple method that does not require large-scale equipment and can effectively increase the yield of vegetables in plant factories. Summary of the Invention

[0005] The purpose of this invention is to provide a method for optimizing the light environment, nutrient solution, and planting density to increase the yield of vegetables in plant factories, thereby solving the problems existing in the prior art. By supplementing far-red light, increasing planting density, and supplementing organic carbon in the nutrient solution, the method achieves high yield of vegetables in plant factories and reduces production costs.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of this invention is to provide a method for increasing vegetable yield in plant factories, comprising the following steps:

[0008] Vegetable seedlings are transplanted onto planting boards for hydroponic cultivation in nutrient solution and continuously illuminated with LED red and blue light and far-red light to increase vegetable yield per unit area.

[0009] The nutrient solution comprises 1 / 2 Hoagland nutrient solution, polyglutamic acid, and seaweed fertilizer; the total volume concentration of polyglutamic acid and seaweed fertilizer in the nutrient solution is 10-15%.

[0010] During hydroponics, the planting density of vegetable seedlings is 50–69 plants / m². 2 ;

[0011] The intensity of the far-red light is 30–50 μmol / (m²). 2 ·s).

[0012] This invention reduces production costs while achieving high yields in plant factory vegetables by supplementing far-red light on top of basic red and blue light, increasing the planting density of vegetable seedlings, and adding polyglutamic acid and seaweed fertilizer to the basic nutrient solution to supplement organic carbon. Specifically, supplementing with far-red light can regulate the plant shape of vegetables, reduce competition for water and nutrients among plants, improve ventilation and light conditions, reduce the occurrence of pests and diseases, and further reduce the ineffective consumption of water and nutrients. The combination of supplementing with far-red light and increasing planting density can improve the light energy utilization rate of vegetables. Simultaneously, supplementing the basic nutrient solution with polyglutamic acid and seaweed fertilizer can provide organic carbon that is easily absorbed and utilized by vegetables, increasing the yield per unit area.

[0013] Preferably, vegetable seeds that have been germinated and have shown white tips are continuously illuminated with LED white light to cultivate strong seedlings.

[0014] Preferably, the light intensity of the LED white light used for cultivating robust seedlings is 200–250 μmol / (m²). 2 •s); The time for cultivating strong seedlings is 12 to 18 days.

[0015] Preferably, the continuous illumination time of the LED red and blue light and far-red light is 12 to 14 hours per day, which is independent.

[0016] Preferably, the illuminance of the red and blue light from the LED is 250 μmol / (m²). 2 ·s); The ratio of red light to blue light in the LED red and blue light is 1 to 3:1.

[0017] Preferably, the mass ratio of polyglutamic acid to seaweed fertilizer in the nutrient solution is 1:1.

[0018] Preferably, the pH value of the 1 / 2 Hoagland nutrient solution is 6-6.5 and the EC value is 1.8-2 ms / cm.

[0019] Preferably, the nutrient solution is applied in an intermittent cycle, with each application lasting 10 minutes and the interval between applications being 20 minutes.

[0020] The present invention discloses the following technical effects:

[0021] Compared with existing technologies for vegetable production in plant factories, this invention uses far-red light to regulate plant shape and increases planting density, which can improve the light energy utilization rate of vegetables. At the same time, it increases the amount of organic carbon that plants can absorb and utilize in the hydroponic nutrient solution, thereby increasing the yield of vegetables per unit area. This helps to promote plant factory production technology, reduce production costs, and play a role in energy conservation and efficiency improvement. Attached Figure Description

[0022] Figure 1 The changes in fresh weight (a), aboveground fresh weight (b), and underground fresh weight (c) of pak choy under different treatments and at different number of days after treatment in Example 1 are shown.

[0023] Figure 2 The changes in the dry weight (a), aboveground dry weight (b), and underground dry weight (c) of pak choi under different treatments and for different number of days after treatment in Example 1 are shown.

[0024] Figure 3 The changes in root-to-shoot ratio of Chinese cabbage under different treatments and for different number of days after treatment in Example 1;

[0025] Figure 4 The changes in the area and yield of the Xiaobai menu under different treatments and for different number of days after the treatment in Example 1;

[0026] Figure 5 The changes in leaf area of ​​Chinese cabbage under different treatments and for different number of days after treatment in Example 1 are shown. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0028] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0030] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0031] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0032] The present invention first describes the raw materials used in the following embodiments:

[0033] The 1 / 2 Hoagland nutrient solution used was prepared in-house, and the preparation method is as follows:

[0034] Preparation of Hoagland nutrient solution: Dissolve calcium nitrate (945 mg / L), potassium nitrate (607 mg / L), ammonium phosphate (115 mg / L), and magnesium sulfate (493 mg / L) in distilled water according to their respective concentrations. Add 2.5 mL of iron salt solution and 5 mL of trace element solution to obtain Hoagland nutrient solution. 1 / 2 Hoagland nutrient solution is obtained by diluting Hoagland nutrient solution with distilled water to half of its original concentration.

[0035] The iron salt solution was prepared by dissolving 2.78 g of ferrous sulfate heptahydrate and 3.73 g of disodium ethylenediaminetetraacetate in 500 mL of distilled water; the trace element solution was prepared by dissolving potassium iodide (0.83 mg / L), boric acid (6.2 mg / L), manganese sulfate (22.3 mg / L), zinc sulfate (8.6 mg / L), sodium molybdate (0.25 mg / L), copper sulfate (0.025 mg / L), and cobalt chloride (0.025 mg / L) in distilled water according to their respective concentrations.

[0036] The seaweed fertilizer and polyglutamic acid used were purchased from DeepGreenTech (Shenzhen) Co., Ltd.

[0037] Unless otherwise specified, all other raw materials are commercially available products.

[0038] Example 1

[0039] Verify the effects of different far-red light intensities and planting densities on the yield increase of Chinese cabbage:

[0040] In an experimental plant factory, plump and clean Chinese cabbage seeds were sown on a 2cm×2cm×2cm moistened sponge block and placed in a germination chamber for germination. Once the seeds showed signs of sprouting, they were placed in a 200μmol / (m²) germination chamber. 2 Seedlings were cultivated under LED white light for two weeks until they had two leaves and one bud. They were then transplanted to 0.9m × 1.2m planting boards for hydroponics. A 1 / 2 Hoagland nutrient solution (pH = 6.5, EC = 2 ms / cm) was used, applied in a cyclical manner with each application lasting 10 minutes and a 20-minute interval between applications. The baseline light intensity was 250 μmol / (m²). 2 Under the condition of LED red and blue light (red:blue light ratio R:B=1:1) supplemented with two LEDs with intensities of 30μmol / (m²) and 30μmol / (m²) respectively. 2 ·s) and 60μmol / (m 2 The far-red light (FR) of LED red and blue light (13 hours of continuous daily illumination) was denoted as FR30 and FR60, respectively. The planting density of the bok choy seedlings during hydroponics was set at 27 plants / m². 2 54 plants / m 2 and 69 plants / m 2 The specific design and the names of the Chinese cabbage seedlings treated under different conditions are shown in Table 1.

[0041] Table 1. Specific Design and Labeling of Chinese Cabbage Seedlings Under Different Treatment Conditions

[0042]

[0043]

[0044] The effects of three different planting densities and two different intensities of far-red light on the growth of Chinese cabbage at different stages, as follows: Figures 1-5 As shown. Figure 1 The changes in fresh weight (a), aboveground fresh weight (b), and underground fresh weight (c) of pak choy under different treatments and at different number of days after treatment in Example 1 are shown. Figure 2 The changes in the dry weight (a), aboveground dry weight (b), and underground dry weight (c) of pak choi under different treatments and for different number of days after treatment in Example 1 are shown. Figure 3 The changes in root-to-shoot ratio of Chinese cabbage under different treatments and for different number of days after treatment in Example 1; Figure 4 The changes in the area and yield of the Xiaobai menu under different treatments and for different number of days after the treatment in Example 1; Figure 5 The changes in leaf area of ​​Chinese cabbage under different treatments and for different number of days after treatment in Example 1 are shown.

[0045] Depend on Figures 1-5 It can be seen that, after 7, 14, 21, and 28 days of far-red light treatment, the fresh-dry weight and total leaf area of ​​pakchoi increased under high-intensity far-red light treatment (HFR) compared to low-intensity far-red light treatment (LFR). After 7 days of treatment, the pakchoi seedlings were small, and different planting densities provided sufficient growth space for the seedlings; therefore, density did not affect the growth of pakchoi at this stage. After 14 days of treatment, compared to 27 plants / m²... 2 Compared to the planting density, 54 plants / m 2 and 69 plants / m 2 Density increases the fresh and dry weight, leaf area, and yield per unit area of ​​*Xylaria heterophylla* plants, while reducing the root-to-shoot ratio. Specifically, 69 plants / m²... 2 Planting density treatment had the most significant effect on promoting the growth of pak choi. After 21 and 28 days of treatment, the growth-related indicators of pak choi under the high-density treatment (54 plants / m²) showed the best results. 2 and 69 plants / m 2 Compared to low density (27 plants / m²) 2 The yield per unit area decreased or showed no significant difference, but the yield per unit area increased.

[0046] Furthermore, the effects of different planting densities and far-red light intensities on pak choi varied considerably. Compared to low-intensity far-red light coupled with low-to-medium density (LFR-27 and LFR-54) or high-intensity far-red light coupled with low density (HFR-27), low-intensity far-red light coupled with high density (LFR-69) or high-intensity far-red light coupled with medium-to-high density (HFR-54 and HFR-69) significantly increased the per-unit area yield of pak choi at 21 and 28 days, but reduced the per-plant fresh-dry weight, root-to-shoot ratio, and leaf area. Specifically, the LFR-54 treatment showed no significant difference in per-plant fresh-dry weight and leaf area compared to LFR-27, but significantly increased the per-plant area yield. Compared to LFR-54, the HFR-27 treatment had a higher per-plant fresh weight, but a significantly lower yield per unit area. Therefore, the low-intensity far-red light coupled with medium density (LFR-54) treatment can significantly increase the yield per unit area while ensuring that the per-plant biomass of pak choi is not affected.

[0047] Example 2

[0048] Verify the effect of nutrient solution formulation on lettuce yield increase:

[0049] In an experimental plant factory, lettuce seeds were sown on a 2cm×2cm×2cm moistened sponge block and placed in a germination chamber for germination. Once the seeds showed signs of sprouting, they were placed in a 200μmol / (m) germination chamber. 2 Seedlings were cultivated under LED white light for two weeks until they reached three leaves and one bud. They were then transplanted to 0.9m × 1.2m planting boards for hydroponics. The nutrient solution used was either 1 / 2 Hoagland nutrient solution (pH = 6.5, EC = 2 ms / cm) (Group H) or 1 / 2 Hoagland nutrient solution (pH = 6.5, EC = 2 ms / cm) + polyglutamic acid + seaweed fertilizer (the total volume concentration of polyglutamic acid and seaweed fertilizer in the nutrient solution was 10%, and the mass ratio of polyglutamic acid to seaweed fertilizer was 1:1) (Group H+C). The nutrient solution was applied in a cyclical manner, with each application lasting 10 minutes and an interval of 20 minutes between applications. The light source was 250 μmol / (m²) light intensity. 2 • LED red and blue light (red:blue light ratio R:B = 1:1) (LED red and blue light continuous illumination for 13 hours daily). The planting density of lettuce seedlings during hydroponics was set at 54 plants / m². 2 Samples were taken and measured 21 days after transplanting. The results are shown in Table 2.

[0050] Table 2 Biomass of the plant species

[0051] deal with Fresh weight of the plant (g) Fresh weight of above-ground parts (g) Fresh root weight (g) <![CDATA[Leaf area (cm 2 )]]> Group H 58.06 48.99 9.07 927.46 H+C group 79.88 67.20 12.68 1140.56

[0052] Table 2 shows that after adding polyglutamic acid and seaweed fertilizer to the 1 / 2 Hoagland nutrient solution, the fresh weight of individual lettuce plants, aboveground parts, and roots increased by 37.58%, 37.17%, and 39.80%, respectively, compared with the 1 / 2 Hoagland nutrient solution treatment (Group H), while the leaf area increased by 22.98%. This indicates that adding polyglutamic acid and seaweed fertilizer to the 1 / 2 Hoagland nutrient solution can significantly increase the organic carbon that vegetables can absorb and utilize, promote vegetable growth, and increase vegetable yield per unit area.

[0053] Example 3

[0054] Verify the effects of supplementing far-red light, increasing planting density, and adding organic carbon to the nutrient solution on increasing lettuce yield:

[0055] In an experimental plant factory, lettuce seeds were sown on a 2cm×2cm×2cm moistened sponge block and placed in a germination chamber for germination. Once the seeds showed signs of sprouting, they were placed in a 200μmol / (m) germination chamber. 2 •s) Cultivate strong seedlings under LED white light. After 2 weeks, when the seedlings have grown to 3 leaves and 1 bud, transplant them to a 0.9m×1.2m planting board with a planting density of 54 plants / m². 2 The basic illumination is a light intensity of 250 μmol / (m²). 2 The LED emits red and blue light (red to blue light ratio R:B = 1:1). The base nutrient solution is a 1 / 2 Hoagland nutrient solution formula (pH = 6.5, EC = 2 ms / cm). The nutrient solution is applied in an intermittent cycle, with each application lasting 10 minutes and an interval of 20 minutes between applications.

[0056] Experimental Treatments: Transplanted lettuce seedlings were divided into three groups. The first group (CK group) received basal light and basal nutrient solution. The second group (H+C group) received basal nutrient solution supplemented with polyglutamic acid and seaweed fertilizer (total volume concentration of polyglutamic acid and seaweed fertilizer in the nutrient solution was 10%, mass ratio of polyglutamic acid to seaweed fertilizer was 1:1) and basal light. The third group received basal nutrient solution supplemented with polyglutamic acid and seaweed fertilizer (total volume concentration of polyglutamic acid and seaweed fertilizer in the nutrient solution was 10%, mass ratio of polyglutamic acid to seaweed fertilizer was 1:1) and basal light was supplemented with an intensity of 50 μmol / (m²). 2 The far-red light (·s) was denoted as group H+C+FR. LED red and blue light and far-red light were continuously irradiated for 14 hours daily. Samples were taken and measured 21 days after transplanting, and the results are shown in Table 3.

[0057] Table 3 Biomass of each plant

[0058] deal with Fresh weight of the plant (g) Fresh weight of above-ground parts (g) Fresh root weight (g) <![CDATA[Leaf area (cm 2 )]]> CK group 60.69 53.77 6.93 1232.92 H+C group 81.86 75.97 5.89 1404.77 H+C+FR group 100.64 94.93 5.71 1693.22

[0059] Table 3 shows that, after adding polyglutamic acid and seaweed fertilizer to the 1 / 2 Hoagland nutrient solution, the number of individual lettuce plants and the above-ground parts increased by 39.95%, 41.16%, and 39.80%, respectively, compared with the 1 / 2 Hoagland nutrient solution treatment (CK group), while the root fresh weight decreased by 15.00% and the leaf area increased by 13.94%. Adding polyglutamic acid and seaweed fertilizer to the 1 / 2 Hoagland nutrient solution, and further supplementing the basal light with 50 μmol / (m²) of light... 2 Under far-red light (·s), the growth rate of individual lettuce plants and the above-ground parts increased by 65.83%, 76.55%, and 39.80%, respectively, compared to the 1 / 2 Hoagland nutrient solution treatment (CK group). Root fresh weight decreased by 17.60%, while leaf area increased by 37.33%. This indicates that the present invention, by using far-red light to regulate plant type combined with increased planting density, can improve the light energy utilization rate of vegetables. Simultaneously, by increasing the amount of organic carbon that plants can absorb and utilize in the hydroponic nutrient solution, it increases vegetable yield per unit area, which helps promote plant factory production technology, reduces production costs, and achieves energy conservation and efficiency improvement.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for increasing vegetable yield in plant factories, characterized in that, Includes the following steps: Vegetable seedlings are transplanted onto planting boards for hydroponics with nutrient solution and continuously illuminated with LED red and blue light and far-red light. The nutrient solution comprises 1 / 2 Hoagland nutrient solution, polyglutamic acid, and seaweed fertilizer; the total volume concentration of polyglutamic acid and seaweed fertilizer in the nutrient solution is 10-15%. During hydroponics, the planting density of vegetable seedlings is 50-69 plants / m². 2 ; The illuminance of the far-red light is 30~50 μmol / (m²). 2 ·s); The method for cultivating vegetable seedlings includes: applying continuous LED white light to vegetable seeds that have already sprouted and turned white to cultivate strong seedlings; The light intensity of the LED white light used to cultivate robust seedlings is 200~250 μmol / (m²). 2 •s); The time for cultivating strong seedlings is 12-18 days; The continuous illumination time of the LED red and blue light and far-red light is 12-14 hours per day, which is independent. The illuminance of the LED's red and blue light is 250 μmol / (m²). 2 ·s); The ratio of red light to blue light in the LED red and blue light is 1~3:1; The mass ratio of polyglutamic acid to seaweed fertilizer in the nutrient solution is 1:

1. The pH value of the 1 / 2 Hoagland nutrient solution is 6~6.5, and the EC value is 1.8~2 ms / cm; The nutrient solution is applied in a cyclical manner, with each application lasting 10 minutes and the interval between applications lasting 20 minutes.

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