A method for reducing the oxalic acid content of spinach and increasing yield in a plant factory

Abstract

The present application relates to the technical field of plant factory planting, in particular to a plant factory planting method for reducing the oxalic acid content of spinach and increasing yield, which provides a brand-new light formula method for planting spinach, uses a certain proportion of far-red light, also uses a certain proportion of yellow-green light, controls the light quantum ratio range of far-red light (700-780 nm) and yellow-green light (500-599 nm) in the light spectrum to be 0.60-1.18, and matches other light spectrum ratios, combines light time and light intensity to form a brand-new light environment regulation scheme, which can effectively reduce the oxalic acid content in the spinach of the plant factory and appropriately increase the yield of the spinach.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plant factory planting technology, in particular to a plant factory planting method for reducing the oxalic acid content of spinach and increasing yield. BACKGROUND

[0002] Spinach, also known as Persian spinach, red-rooted spinach, parrot spinach and red spinach, is a chenopodiaceae plant. It has been cultivated in China for more than 2,000 years and is a world vegetable crop. It is rich in nutrients and is deeply loved by consumers. Spinach contains a large amount of plant fiber, which can promote intestinal peristalsis, help digestion, and promote the secretion of the pancreas. The carotene contained in spinach can be converted into vitamin A in the human body, which can maintain normal vision and the health of epithelial cells, increase the ability to prevent infectious diseases, and promote the growth and development of children. The iron and vitamin E contained in spinach can provide the human body with a variety of nutrients, and the iron contained in spinach has a good auxiliary treatment effect on iron deficiency anemia. Eating a large amount of spinach can reduce the risk of stroke.

[0003] The market demand for spinach is huge, but the traditional field planting has a long cycle, low yield, and insufficient supply, which leads to high prices of spinach. In addition, spinach is cold-tolerant but not heat-tolerant, and temperature has a great influence on spinach planting. The relatively strict planting environment requirements lead to the fact that traditional field planting of spinach cannot be produced throughout the year. Plant factory is a high-level stage of modern facility agriculture and is the main trend of future agricultural development. Because the light, temperature, humidity and fertilizer in the plant factory can be controlled as needed, the plant production cycle is greatly shortened, the yield is improved, and the plant factory can produce throughout the year to meet the market demand in each season. As a high-value vegetable, spinach is one of the main planting varieties in the future plant factory.

[0004] Controlling light in the environmental conditions has a certain influence on the growth and oxalic acid content of spinach. Photosynthesis is one of the key processes for spinach to synthesize nutrients, and the synthesis of oxalic acid is also related to light. Controlling light helps to reduce the oxalic acid content of spinach:

[0005] Light intensity: appropriate light intensity helps to reduce the oxalic acid content. Generally, the light intensity of spinach should be controlled between 8000-12000 lux, too weak light will affect photosynthesis, and too strong light will also cause plant stress, thereby promoting the synthesis of oxalic acid.

[0006] Light time: appropriate light time also helps to reduce the oxalic acid content. Spinach needs light for growth, but too long light time will cause spinach to appear bolting problem in advance. Therefore, generally speaking, it is more appropriate to control the light time between 10-12 hours per day.

[0007] The effect of different wavelengths of light on the content of oxalic acid is different. Qilian Dong et al. found that monochromatic red and blue light can help reduce the synthesis of oxalic acid, while yellow light can promote the synthesis of oxalic acid. Therefore, the quality of light can be adjusted by controlling the color and combination of light sources to reduce the content of oxalic acid.

[0008] The far-red wavelength with biological effects on plants is between 700-780nm, which belongs to the part of infrared spectrum. Generally, the industry recognizes that the photosynthetically active radiation range is 400-700nm, and the far-red waveband range is not considered to have a positive effect on plants. Patent CN106069144A discloses a method for planting spinach in artificial light type plant factory, which cancels the use of far-red waveband range during the vegetative growth and harvest periods of spinach, which can reduce the content of oxalic acid in spinach. Red light wavelength is between 600-699nm, which has an important influence on the photosynthesis of spinach. Red light can promote the production of chlorophyll and carotenoids and other pigments in spinach, promote the growth and development of plants, and enhance the disease resistance of plants.

[0009] Blue light wavelength is between 400-499nm, which has an important influence on the growth and flowering of spinach. Blue light can promote the growth and flowering of spinach, increase the yield and quality of plants, and also can inhibit the elongation of plants, increase the tightness of plants. The content of oxalic acid in spinach under blue light irradiation is significantly lower than that under other light quality irradiation. This may be related to the promotion of blue light on the growth and photosynthesis of plants, thereby reducing the accumulation of oxalic acid. At the same time, blue light can also regulate the morphology and growth rhythm of plants, and improve the yield and quality of plants. The effect of blue light on the content of oxalic acid in spinach may be influenced by the light time and intensity.

[0010] Under the mixed light irradiation of red and blue light, the content of oxalic acid in spinach decreases, and the effect of red light is more obvious. This may be related to the fact that red light can promote the photosynthesis of spinach, increase the accumulation of photosynthetic products of plants, and thus reduce the content of oxalic acid. At the same time, red light can promote the growth and flowering of spinach, thereby improving the yield and quality of plants. Yellow-green light wavelength is between 500-599nm, which has relatively small influence on the growth of spinach. Yellow-green light can promote the growth and development of spinach, but it is not as obvious as the influence of red light and blue light on plant growth. At present, the research on the influence of yellow-green light on the content of oxalic acid in spinach is still limited, but some studies have shown that yellow-green light may have some influence on the content of oxalic acid. Qilian Dong et al. found that the use of yellow-green light irradiation during the growth of spinach increased the content of oxalic acid in spinach leaves, which may be related to the fact that yellow-green light reduced the photosynthesis of spinach and reduced the activity of some enzymes required for the degradation of oxalic acid.

[0011] In addition, there may be interactions between different light qualities, affecting their influence on oxalic acid content. It is necessary to develop and innovate in terms of light source selection, light intensity and time control, etc. Therefore, selecting the appropriate light quality ratio and irradiation conditions is the key to improving the yield and quality of spinach. However, as mentioned above, yellow-green light and far-red light may increase the accumulation of oxalic acid in spinach. In order to reduce the oxalic acid content of spinach, yellow-green light and far-red light should be avoided as much as possible. At the same time, far-red light has a relatively weak effect on spinach plant growth, and the person skilled in the art also tries to use as little as possible or even not to use it during the cultivation of spinach. SUMMARY

[0012] However, the use of traditional white light or red and blue light in plant factory cultivation of spinach not only has low yield, but also has high oxalic acid content. Therefore, the present inventors have overcome the above technical biases, and the present application provides a brand new light formula method for cultivating spinach, which not only uses a certain proportion of far-red light, but also uses a certain proportion of yellow-green light. The light quantum ratio range of far-red light (700-780 nm) and yellow-green light (500-599 nm) is controlled in the range of 0.60-1.18, and other light spectrum ratios are matched, combined with light time and light intensity to form a brand new light environment regulation scheme, which can effectively reduce the oxalic acid content in plant factory spinach and appropriately increase the yield of spinach.

[0013] To achieve the above-mentioned purpose, the present application provides a plant factory cultivation method for reducing the oxalic acid content of spinach and increasing the yield, comprising:

[0014] (1) Germination;

[0015] (2) Seedling;

[0016] (3) Planting; characterized in that, during the process of (2) seedling and (3) planting, the light quantum ratio range of far-red light (700-780 nm) and yellow-green light (500-599 nm) is controlled in the range of 0.60-1.18, and the light quantum ratio of yellow-green light (500-599 nm) in the range of 380-780 nm is controlled in the range of 15-26%, the light quantum ratio of far-red light (700-780 nm) in the range of 380-780 nm is controlled in the range of 12-20%, the light quantum ratio of blue light (400-499 nm) in the range of 380-780 nm is controlled in the range of 16-20%, and the light quantum ratio of red light (600-699 nm) in the range of 380-780 nm is controlled in the range of 42-48%; the photoperiod is 10-13h / d, and the light intensity range is 180-250μmol / ㎡·s.

[0017] Further, in the (1) seed germination step, the seeds are soaked in warm water at 28-32 DEG C for 6-8 hours, then sowed in sponge blocks with one seed per hole, and placed in a 23-25 DEG C germination box for germination, and after the seeds are white, moved to a light culture rack for growth in the seedling stage.

[0018] Further, in the (2) seedling stage, the EC value of the nutrient solution during the treatment is 1.2-1.5 mS / cm, the pH value is 6.0-7.0, the light spectrum meets the light quantum distribution proposed in the application, the photoperiod is 12-13 h / d, and the light intensity is 200-250 μmol / m 2 ·s.

[0019] Further, in the (3) planting step, when the spinach seedlings grow to 4-5 true leaves, cultivation and planting are carried out, moved to a planting plate, and placed in a nutrient solution tank for culture, and during the planting period, the EC value of the nutrient solution is controlled at 1.7-2.0 mS / cm, the pH value is 6.0-7.0, the nutrient solution temperature is 20-22 DEG C, the dissolved oxygen content is 5-6 mg / L, the environmental temperature conditions are 20-23 DEG C during the day and 18-20 DEG C at night, the air humidity is 70-85%, the CO2 concentration is 400-1000 ppm, the light environment is controlled, the light spectrum meets the light quantum distribution proposed above, the photoperiod is 10-11 h / d, and the light intensity is 180-220 μmol / m 2 ·s.

[0020] The above technical solution has the following beneficial effects:

[0021] The application overcomes the technical bias in the technical field, controls the light environment in the spinach plant factory seed method, uses a certain proportion of far-red light, also uses a certain proportion of yellow-green light, controls the light quantum ratio range of the far-red light (700-780 nm) and the yellow-green light (500-599 nm) at 0.60-1.18, and matches other light spectrum ratios, combines light time and light intensity to form a new light environment regulation scheme, which can effectively reduce the oxalic acid content in the spinach plant factory, and appropriately increase the spinach yield. DETAILED DESCRIPTION

[0022] To illustrate the technical content, structural features, purposes and effects of the technical scheme in detail, the following will be described in detail with specific examples.

[0023] Examples 1-7

[0024] Experimental purposes: in order to verify the technical scheme adopted in the present application can reduce the content of oxalic acid in spinach while effectively improving the yield of spinach, which has made significant progress. The following methods and conditions are used in examples 1-7, and control examples 1-11 are provided for examples 1-7. Through the comparison between examples 1-7 and control examples 1-11, the practicability and market value of the light formula used in the present application are proved.

[0025] The spinach plant factory planting method in examples 1-7, wherein the nutrient solution ratio, light intensity in (1) germination step, (2) seedling and (3) planting steps are the same, the seeds of full grain shaw spinach are selected, the seeds are soaked for 6h, then 1 grain is planted in each hole, and then placed in a 23℃ germination box for germination. After the seeds are white, they are moved to the water culture nutrient solution for seedling management, the EC value of the nutrient solution is 1.2-1.5mS / cm, the pH value is 6.0-7.0, and the cultivation is carried out until 4-5 true leaves are grown. The uniform and consistent seedlings with 4-5 true leaves are selected and transplanted to the planting plate and placed in the nutrient solution tank for culture, the EC value of the nutrient solution is controlled between 1.7-2.0mS / cm, the pH value is 6.0-7.0, and the nutrient solution temperature is controlled at 21℃ during the whole planting period, the dissolved oxygen is 5-6mg / L, the environmental temperature conditions are 21℃ during the day and 19℃ at night, the air humidity is 70-85%, and the CO2 concentration is 1000ppm. The light intensity is 200μmol·m -2 ·s -1 , and the light period is 10.5h / d.

[0026] The difference between the 7 examples is that 7 kinds of example spectra are set for LED light source, (2) seedling and (3) planting period respectively adopts different light formula environment, and the spectral quantum distribution range of the light formula environment is controlled to meet the following conditions: the light quantum proportion range of far red light (700-780nm) and yellow green light (500-599nm) is controlled in 0.60-1.18, and the light quantum proportion of yellow green light (500-599nm) in 380-780nm is controlled in 15-26%, the light quantum proportion of far red light (700-780nm) in 380-780nm is controlled in 12-20%, the light quantum proportion of blue light (400-499nm) in 380-780nm is controlled in 16-20%, and the light quantum proportion of red light (600-699nm) in 380-780nm is controlled in 42-48%. The light period is 10-13h / d, and the light intensity range is 180-250μmol / ㎡·s.

[0027] Control examples 1-11

[0028] The control examples 1-11 are also spinach plant factory cultivation methods, wherein (1) the germination step, (2) the seedling and (3) the planting steps have the same nutrient solution ratio and light intensity, full seed of the spinach is selected, the seed is soaked for 6h, and then 1 seed is planted in each hole of a sponge block, and then placed in a 23°C germination box for germination. After the seed is white, it is moved to the water culture nutrient solution for seedling management, the nutrient solution EC value is 1.2-1.5mS / cm, the pH value is 6.0-7.0, and it is cultivated until 4-5 true leaves are grown. The uniform and consistent seedlings with 4-5 true leaves are selected and transplanted to the planting plate and placed in the nutrient solution tank for culture, the nutrient solution EC value is controlled between 1.7-2.0mS / cm, the pH value is 6.0-7.0, and the nutrient solution temperature is controlled at 21°C during the whole planting period, the dissolved oxygen is 5-6mg / L, the environmental temperature condition is 21°C during the day and 19°C at night, the air humidity is 70-85%, and the CO2 concentration is 1000ppm. The light intensity is 200μmol·m -2 ·s -1 The light period is 10.5h / d, and the light spectrum of the 11 control examples does not meet the light spectrum quantum distribution range of the light formula environment controlled in the above examples.

[0029] The spinach is cultivated according to the above cultivation method in the examples 1-7 and the control examples 1-11, and after 17d of cultivation, the related morphological data of each example and control example are counted, and the net photosynthetic rate Pn parameter test is performed using a Li-6800 photosynthetic instrument. The test results are shown in Table 1.

[0030] Table 1

[0031]

[0032] Test result analysis: the control examples 1-3 are conventionally selected white light or red and blue light, and the use of appropriate red and blue light ratio can reduce the oxalic acid content of spinach compared with white light, and it has been disclosed by researchers that the use of yellow-green light or the use of far-red light will increase the oxalic acid content of spinach, so the professional technical personnel in the field will mainly select from red and blue light when selecting light spectrum for spinach planting. Compared with the 11 control examples, the examples 1-7 adopt the proportion mode of far-red light combined with yellow-green light, and combine the application of some other light spectrum, which breaks the technical bias of the prior art means, and the oxalic acid content of the spinach in the examples 1-7 is greatly reduced, and the yield is obviously improved, which achieves unexpected technical effects.

[0033] As described in the background of the present disclosure, the use of yellow-green light and far-red light can increase the accumulation of oxalic acid in spinach. In order to reduce the content of oxalic acid in spinach, the use of yellow-green light and far-red light should be avoided as much as possible. At the same time, the role of far-red light in the growth of spinach plants is relatively weak, and in the process of spinach planting, those skilled in the art also try to use as little or even no far-red light. In the present scheme, the above technical biases are overcome by adopting a brand new light formula method for planting spinach. Not only a certain proportion of far-red light is used, but also a certain proportion of yellow-green light is used, and the light quantum ratio range of far-red light (700-780 nm) and yellow-green light (500-599 nm) is controlled in the range of 0.60-1.18, and other light spectrum ratios are matched, combined with light time and light intensity to form a brand new light environment regulation scheme. The net photosynthetic rate of spinach under the light spectrum scheme of embodiments 1-7 is significantly higher than that of control examples 1-11. The appropriate proportion of far-red light and yellow-green light combined with other light spectrum excites the photosynthetic capacity of the plant itself. Compared with control examples 1-11, the photosynthesis of spinach under the light spectrum of embodiments 1-7 is stronger, which may also promote the increase of oxalic acid decarboxylase activity and accelerate the degradation of oxalic acid in spinach, thereby effectively reducing the content of oxalic acid in the plant factory spinach. At the same time, the net photosynthetic rate of spinach under the treatment of embodiments 1-7 is higher, thereby appropriately increasing the yield of spinach.

[0034] It should be noted that, in this document, the terms such as first and second are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or terminal device. Without more limitations, the elements defined by the statement "comprising" or "including" do not exclude the presence of other elements in the process, method, article or terminal device including the elements. In addition, in this document, "greater than", "less than", "exceed" and the like are understood as not including the number itself; "above", "below", "within" and the like are understood as including the number itself.

[0035] Although the above embodiments have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic creative concept, so the above description is only an embodiment of the present application, and does not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation made by using the present application specification, or directly or indirectly used in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield, characterized by, It comprises (1) germination; (2) seedling; (3) planting; characterized in that, In the process of (2) seedling and (3) planting, the ratio of far-red light (700-780 nm) to yellow-green light (500-599 nm) is controlled in the range of 0.60-1.18, and the proportion of yellow-green light (500-599 nm) in the range of 380-780 nm is controlled in the range of 15-26%, the proportion of far-red light (700-780 nm) in the range of 380-780 nm is controlled in the range of 12-20%, the proportion of blue light (400-499 nm) in the range of 380-780 nm is controlled in the range of 16-20%, and the proportion of red light (600-699 nm) in the range of 380-780 nm is controlled in the range of 42-48%; the photoperiod is 10-13 h / d, and the light intensity is 180-250 µmol / ㎡•s.

2. The plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield according to claim 1, characterized by, In the (1) germination step, the seeds are soaked in warm water at 28-32℃ for 6-8h, then sowed in sponge blocks with one seed per hole, and placed in a 23-25℃ germination box for germination, and then moved to a light culture rack for seedling growth after the seeds are white.

3. The plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield according to claim 1, characterized by, In the (2) seedling step, the EC value of the nutrient solution during treatment is 1.2-1.5 mS / cm, the pH value is 6.0-7.0, the photoperiod is 12-13 h / d, and the light intensity is 200-250 µmol / ㎡•s.

4. The plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield according to any one of claims 1 to 3, characterized by, In the (3) planting step, when the spinach seedlings grow to 4-5 true leaves, they are planted and moved to the planting plate and placed in the nutrient solution tank for culture, and the EC value of the nutrient solution during planting is controlled in the range of 1.7-2.0 mS / cm, and the pH value is 6.0-7.0; the nutrient solution temperature is 20-22℃, the dissolved oxygen content is 5-6 mg / L, the environmental temperature conditions are 20-23℃ during the day and 18-20℃ at night, the air humidity is 70-85%, the CO2 concentration is 400-1000 ppm, the photoperiod is 10-11 h / d, and the light intensity is 180-220 µmol / ㎡•s.

5. The plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield according to claim 1, characterized by, The photoperiod during the planting of spinach is 10.5 h / d.

6. The plant factory cultivation method for reducing the oxalic acid content of spinach and increasing yield according to claim 1, characterized by, The EC value of the nutrient solution during the planting of spinach is controlled in the range of 1.7-2.0 mS / cm.

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