Soilless culture method for caragana microphylla in underground three-dimensional farm

Abstract

The soilless culture method for the caragana microphylla in the underground three-dimensional farm comprises the steps that high-quality caragana microphylla seeds are selected, then the seeds are soaked and subjected to constant-temperature oxygenation treatment, then water is drained off, and under the controlled temperature, humidity and illumination conditions, seed germination accelerating treatment is conducted to promote seed germination. The germinated seeds are sown in a seedling culture medium, temperature, humidity and illumination management is conducted, and germination of the seeds is promoted. When the true leaves of the seeds grow to a certain height, the stem diameter and time are counted. According to the method, the seeds are systematically pretreated, so that the dormant state of the seeds is effectively broken, the problems of non-uniform germination and overlong germination time caused by improper environment or improper treatment are reduced, the germination rate is increased, and the germination time is shortened. Particularly, by controlling the components and proportion of the seedling culture substrate and the illumination condition of artificial light, the optimal condition can be provided for rapid growth of caragana microphylla seeds, the seedling culture period is shortened, and the seedling culture quality is improved.

Description

Technical Field

[0001] This invention relates to the field of soilless cultivation technology, specifically to a method for soilless cultivation of Caragana korshinskii in an underground three-dimensional farm. Background Technology

[0002] Caragana korshinskii, also known as hairy caragana or white caragana, thrives on sunny and semi-sunny slopes at altitudes of 900-1300 meters. It exhibits wide adaptability to environmental conditions and possesses a xerophytic structure, demonstrating strong resistance to drought, heat, cold, and salinity. Caragana korshinskii is an important tree species for soil and water conservation and sand fixation afforestation in Northwest, North, and western Northeast China, serving as an excellent plant for sand fixation and greening barren mountains, as well as a good source of forage and compost. Its roots, flowers, and seeds can all be used medicinally, acting as a yin-nourishing, blood-tonifying, menstruation-regulating, and sedative agent. Caragana korshinskii can grow normally at temperatures as low as -32℃ and with soil temperatures reaching 55℃. Direct sowing of Caragana korshinskii seeds has a germination rate of over 85%, with seedlings emerging normally within 10 days. However, the seedling emergence period is relatively long, and direct sowing outdoors may result in germination failure or seedling death, requiring replanting later, increasing planting costs.

[0003] Caragana is a drought-tolerant, deciduous shrub belonging to the genus Caragana in the legume family. It has extremely strong drought resistance, cold resistance, and tolerance to poor soil conditions. It is a core pioneer plant for windbreak and sand fixation, soil and water conservation, and desertification control in northern my country. At the same time, its tender branches and leaves are rich in nutrients such as crude protein and crude fiber, and can be used as high-quality forage. Its seeds can also be used for oil extraction and medicine, thus having both ecological benefits and economic value. Traditional Caragana cultivation mainly relies on direct seeding in open fields or seedling transplanting, depending on natural soil and climate conditions, which has obvious limitations: First, the planting area is concentrated in the arid and semi-arid regions of the north, making it difficult to promote on a large scale in areas such as urban peripheries and unsuitable arable land; Second, open-field cultivation is greatly affected by natural factors such as rainfall, temperature, and pests and diseases, resulting in unstable germination and survival rates, and a long growth cycle, making it difficult to quickly form ecological protection benefits and forage production capacity; Third, continuous cropping in the soil easily leads to soil-borne diseases, resulting in weakened growth of Caragana, while the traditional cultivation model has low water and fertilizer utilization efficiency, with prominent problems of water waste and nutrient loss; Fourth, the industrial development of Caragana is limited by the production area and supply cycle, with insufficient local supply capacity of fresh tender branches and leaves, which restricts the extension of its industrial chain such as forage and deep processing.

[0004] With the development of facility agriculture and soilless cultivation technology, plant factories have become an important direction for breaking through the bottlenecks of traditional agriculture due to their ability to precisely control environmental factors, break free from soil limitations, and achieve year-round high-efficiency crop production. Underground plant factories, relying on the advantages of stable underground space, isolation from external pests and diseases, and no occupation of arable land, can further reduce energy consumption for environmental control and improve production stability, making them particularly suitable for intensive planting in areas such as urban suburbs and surrounding industrial and mining wastelands. However, the application of hydroponics technology in the cultivation of Caragana korshinskii is still in its infancy. Existing underground plant factory cultivation systems are mainly designed for leafy vegetables, fruits, and other crops, and cannot be adapted to the growth characteristics of Caragana korshinskii shrubs. First, the physicochemical properties of existing hydroponic substrates or hydroponic systems are difficult to meet the needs of Caragana korshinskii's deep root system and vigorous respiration, which can easily lead to root hypoxia and root rot. Second, the environmental control parameters of underground plant factories, such as light, temperature, humidity, and carbon dioxide concentration, lack optimized solutions for Caragana korshinskii growth. Blindly applying the control standards for leafy vegetables will cause Caragana korshinskii to grow excessively and have insufficient lignification. Third, the structural design of underground three-dimensional cultivation racks does not take into account the plant expansion characteristics of Caragana korshinskii, resulting in low space utilization and a lack of supporting intensive management and harvesting devices. Fourth, the existing water and fertilizer integration systems of underground plant factories mostly adopt a high water and fertilizer supply mode, which is incompatible with the physiological characteristics of Caragana korshinskii's tolerance to poor soil, which not only increases production costs but also leads to nutrient waste and secondary pollution.

[0005] At the same time, my country has abundant underground space resources, and a large number of underground civil defense projects, idle underground garages, and underground factories have not been used efficiently. Transforming them into plant factories for hydroponic cultivation of Caragana korshinskii can not only expand the planting space of Caragana korshinskii, but also realize the resource utilization of idle underground space.

[0006] Therefore, developing a soilless cultivation technology for Caragana korshinskii adapted to the environment of underground plant factories, solving the limitations of traditional open-field cultivation and the compatibility problem with existing underground plant factory cultivation systems, and realizing intensive, efficient, and year-round production of Caragana korshinskii, has important practical significance and application value for promoting the integrated development of Caragana korshinskii ecological governance and industrial development. Summary of the Invention

[0007] In view of the above shortcomings, the present invention, in the environment of a plant factory, through seed germination treatment, seedling substrate and LED artificial light regulation, can shorten the germination time and seedling cycle, enhance the robustness of transplanted plants, and greatly improve the survival rate of planted plants. Caragana korshinskii requires less water during the seedling stage, and excessive irrigation should not be carried out at this stage. Caragana korshinskii seedlings can be transplanted when they grow to 8-10 cm.

[0008] To achieve the above-mentioned technical effects, the present invention employs the following technical means: This invention first discloses a method for hydroponically cultivating Caragana korshinskii in an underground three-dimensional farm, comprising: S1: Select high-quality Caragana seeds; S2: Pre-treat the seeds selected in S1, including soaking, constant temperature oxygenation and hormone treatment, to break the seed dormancy. S3: Drain the pretreated seeds and carry out seed germination treatment under controlled temperature, humidity and light conditions to promote seed germination. S4: Prepare the seedling substrate to provide a good environment for seed germination; S5: Sow the germinated seeds in the seedling substrate and manage the temperature, humidity and light to promote seed germination; S6: When the true leaves of the seed emerge from the ground at a height of 1cm, the stem diameter and time are recorded.

[0009] By systematically pre-treating the seeds, including soaking and constant-temperature aeration, the dormancy state of the seeds is effectively broken, reducing uneven germination and excessively long germination times caused by improper environment or treatment, thereby improving the germination rate and shortening the germination time. In particular, by controlling the composition and ratio of the seedling substrate and the artificial light conditions, optimal conditions can be provided for the rapid growth of Caragana korshinskii seeds, shortening the seedling cycle and improving seedling quality.

[0010] Seed germination of *Caragana korshinskii*: 400 seeds (approximately 16g) with a purity ≥90% were selected. In the experimental group, 100 seeds were soaked in 0.02% boric acid for 4 hours, then slightly dried. Afterward, they were soaked in water at 25℃ for 12 hours using a constant temperature aeration device. After 12 hours, the seeds were drained with gauze. The seeds and gauze were placed on a permeable tray, spread evenly, and covered with another damp gauze to maintain moisture. The tray was then placed in the dark at a room temperature of 25-28℃. Germination rate was recorded after 24 hours, as well as the germination time required to reach 95%. Germination data was recorded every 8-12 hours after 24 hours of germination, as follows: t0: Start germination; t+24h: First statistic (germination rate); t+32h: Second statistical analysis; t+40h: Third statistical analysis; t+48h: Fourth statistical analysis; t+60h: Fifth statistical analysis; t+72h: Sixth statistical analysis; After that, statistics were collected every 24 hours until germination ended.

[0011] Germination standard: When the true leaves of the seed emerge 1cm above the ground. Germinated seeds that have been counted should be removed promptly for transplanting.

[0012] Germination rate: Germination rate calculated after 24 hours of germination. Germination time: The germination time required to achieve a germination rate of 95%.

[0013] The beneficial effects of this invention are as follows: 1. Caragana seeds have poor germination ability. Using constant temperature and oxygenation and reagent treatment can shorten the germination time and increase the germination rate.

[0014] 2. Adjusting the seedling substrate and LED artificial light can shorten the seedling cycle, make the plants grow stronger, and improve the seedling survival rate.

[0015] 3. This invention employs a systematic pretreatment process for seeds, including soaking, constant temperature oxygenation, and hormone treatment. This effectively breaks the seed dormancy state, reduces uneven germination and excessively long germination times caused by improper environment or treatment, improves germination rate, and shortens germination time. In particular, by controlling the composition and ratio of the seedling substrate and the artificial light conditions, it provides optimal conditions for the rapid growth of Caragana korshinskii seeds, shortening the seedling cycle and improving seedling quality. Detailed Implementation

[0016] To enable those skilled in the art to better understand this solution, the following detailed description is provided in conjunction with specific embodiments. Unless otherwise specified, the process methods used in the embodiments are conventional methods; and unless otherwise specified, the materials used are commercially available.

[0017] Example 1

[0018] Seed germination of *Caragana korshinskii*: Select *Caragana korshinskii* seeds (approximately 16g) with a purity ≥90%. In the experimental group, 100 seeds were soaked in 0.02% boric acid for 4 hours, then slightly dried. Next, soaked in clean water at 25℃ for 12 hours using a constant temperature aeration device. After 12 hours, drain the seeds with gauze. Place the seeds and gauze on a permeable tray, spreading them evenly. Cover the surface with another damp gauze to maintain moisture. Place in the dark at a room temperature of 25-28℃. Germination rate was recorded after 24 hours, along with the germination time required to reach 95%. Germination data was recorded every 8-12 hours after 24 hours of germination, as follows: t0: Start germination; t+24h: First statistic (germination rate); t+32h: Second statistical analysis; t+40h: Third statistical analysis; t+48h: Fourth statistical analysis; t+60h: Fifth statistical analysis; t+72h: Sixth statistical analysis; After that, statistics were collected every 24 hours until germination ended.

[0019] Germination standard: When the true leaves of the seeds emerge 1cm above the ground, the germinated seeds that have been counted should be removed in time for transplanting.

[0020] Germination rate: Germination rate calculated after 24 hours of germination. Germination time: The germination time required to achieve a germination rate of 95%.

[0021] Control group 1 One hundred seeds were selected and soaked in 0.02% boric acid for 4 hours. The seeds were then drained with gauze, and the subsequent operation steps were the same as those of the experimental group.

[0022] Control group 2 One hundred seeds were selected and soaked in clean water at 25°C for 12 hours using a constant temperature oxygenation device. After 12 hours, the seeds were drained with gauze, and the subsequent operation steps were the same as those of the experimental group.

[0023] Control group 3 One hundred seeds were selected and soaked in water at room temperature (25-28℃) for 12 hours. After 12 hours, the seeds were drained with gauze, and the subsequent operation steps were the same as those of the experimental group.

[0024] Table 1

[0025] In summary, when treating seeds, the germination rate of seeds treated with control group 1 or control group 2 was significantly better than that of control group 3 after 24 hours, and the germination time required to reach 95% was also significantly shorter. Conversely, the germination rate of seeds in the experimental group after 24 hours was significantly better than that of control groups 1 and 2, and the germination time required to reach 95% was significantly shorter than that of control groups 1 and 2.

[0026] 2. Preparation of seedling substrate and substrate planting: When the seed germination rate reaches 95%, transplanting can be carried out.

[0027] Experimental group A1: Peat moss, perlite and vermiculite were mixed in a ratio of 1:2:1.

[0028] Experimental Group A2: Peat moss, corn cobs (particle size ≤ 0.5cm), and vermiculite were mixed in a ratio of 1:1.5:1. The corn cobs provided physical support and nutrient supply, reducing seedling costs.

[0029] Disinfect the mixed substrate and 36-cell seedling trays with carbendazim spray, and moisten the substrate until it can be squeezed into a ball and water seeps between your fingers without dripping. First, spread the substrate evenly to fill 2 / 3 of the seedling tray. Using tweezers, place 2 sprouted seeds in the center of each cell, then cover the surface with a thin layer of soil. Finally, water thoroughly until water seeps out to the bottom of the tray, and place a tray under the tray. Add water to the bottom of the tray every 4-5 days, adjusting the amount of water according to the substrate moisture.

[0030] Experimental Group B1: Placed under artificial light, with conventional seedling lighting conditions (referencing common field crop seedling cultivation): photoperiod 20 / 4 (20h light, 4h darkness), light quality ratio: red-blue-white-far-red ratio (R:B:W:FR) = 100:100:100:50 (2:2:2:1), light intensity 250μmol / m²s, temperature 20-28℃, humidity 70-85%. The time required for seeds to grow to 8-10cm and the stem diameter at the first leaf on the above-ground part were recorded.

[0031] Experimental group B2: Placed under artificial light, photoperiod 18 / 6 (18h light, 6h darkness), light quality ratio: red-blue-white-far-red ratio (R:B:W:FR) = 100:70:70:20 (3.8:2.7:2.7:0.8), light intensity 400 μmol / m² 2 / s, temperature 20-28℃, humidity 70-85%. During this period, the time required for seeds to grow to 8-10cm and the stem diameter at the first leaf of the above-ground part were recorded.

[0032] Each experimental group consists of a 36-well seed tray with 2 seedlings per hole. Under conditions A1B1, the stem diameter is calculated by randomly selecting 10 seedlings from the 36-well seed tray and calculating the average value.

[0033] Table 2

[0034] In summary, during the seedling and transplanting period, experimental group A2, which added corn cobs, and experimental group B2, which adjusted the light conditions for seedlings of common field crops by increasing light intensity and regulating light quality ratio and photoperiod, both achieved the shortest seedling period and the thickest plant stems. By adjusting the seedling substrate and artificial light control, the seedling period was shortened by one-third compared to the conventional method, and the stem diameter was twice that of conventional seedling cultivation.

[0035] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods and processes are not described in detail.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for hydroponically cultivating Caragana korshinskii in an underground vertical farm, comprising: S1: Select high-quality Caragana seeds and soak and oxygenate them at a constant temperature to obtain pretreated seeds; S2: Drain the pretreated seeds and carry out seed germination treatment under controlled temperature, humidity and light conditions to obtain germinated seeds. S3: Sow the germinated seeds in the seedling substrate and manage the temperature, humidity and light to promote seed germination; S4: When the true leaves of the seeds emerge 1cm above the ground, count the stem diameter and time. Seeds that have been counted should be removed in time for transplanting.

2. The method according to claim 1, wherein: The high-quality Caragana seeds mentioned in step S1 include Caragana seeds with a purity of ≥90%.

3. The method according to claim 1, wherein: The soaking treatment in step S1 includes: Soak in 0.02% boric acid for 4 hours.

4. The method according to claim 1, wherein: Step S1, which involves constant temperature oxygenation, includes: draining the seeds after they have been soaked in boric acid, placing them in a water tank equipped with a constant temperature oxygenation device, and setting the temperature of the device to 25°C.

5. The method according to claim 1, wherein: The controlled temperature, humidity, and light conditions described in step S2 include: Store in the shade at a room temperature of 25-28℃.

6. The method according to claim 1, wherein: The seedling substrate mentioned in step S3 is prepared by the following method: Mix peat moss, corn cobs, and vermiculite in a mass ratio of 1:1.5:

1. Disinfect the mixed substrate and 36-cell seedling trays with carbendazim, and moisten the substrate until it can be squeezed into a ball by hand with water visible between the fingers but no water dripping down.

7. The method according to claim 6, wherein: The corn cob particle size is ≤0.5cm.

8. The method according to claim 1, wherein: Step S3, which involves temperature, humidity, and light management, includes: Place the germinated seeds under a plant growth lamp and expose them to light for 18 hours, then place them in the dark for 6 hours. The relative proportions of red, blue, white, and far-red light components in the spectrum of the plant grow lamp are 100:70:70:20, with a light intensity of 400 μmol / m². 2 / s, temperature 20-28℃, humidity 70-85%.

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