A cultivation box for seedling of forage grass

Abstract

The application discloses a kind of pasture seedling cultivation with cultivation box, belong to pasture seedling equipment technical field.The cultivation box includes box body, independent temperature and humidity control system, intelligent illumination system, circulating irrigation system and control system.Laminated setting can be pulled and drawn seedling tray in box body, and bionic capillary penetration layer is laid in the bottom of seedling tray and is provided with breathable water seepage hole.Temperature and humidity control system adopts graphene even heating strip and semiconductor refrigeration heating module to form temperature gradient field;Intelligent illumination system realizes light quality adaptive output by LED light spectrum matrix and sensor array;Circulating irrigation system is configured with seepage irrigation pipeline and micro-permeation hole with gradually increasing aperture, to ensure irrigation uniformity;Mechanical lifting type air root pruning device is specially set, and the tip of root is induced lateral root proliferation by electric heating wire ring hot cutting.The present application solves the problems of rhizosphere anoxia, uneven light and heat and poor seedling quality in pasture seedling, and significantly improves germination rate and transplanting survival rate.

Description

Technical Field

[0001] This invention relates to the field of forage seedling equipment technology, specifically to a forage seedling cultivation box. Background Technology

[0002] Forage grass is the material foundation for the development of herbivorous animal husbandry, and the large-scale production of high-quality forage grass directly affects the yield and quality of livestock products. In recent years, with the continuous expansion of artificial grassland construction and the in-depth promotion of the transformation and upgrading of the grass-based animal husbandry industry, factory-style forage grass seedling cultivation technology has received increasing attention. Traditional field forage grass seedling cultivation is constrained by multiple factors such as climate conditions, soil conditions, and pests and diseases, resulting in low germination rates, long seedling cycles, and poor seedling uniformity, making it difficult to meet the demand for high-quality seedlings in large-scale planting. Therefore, indoor controlled-environment seedling cultivation devices have emerged.

[0003] In the prior art, some cultivation devices for forage seedlings have emerged. For example, Chinese utility model patent publication number CN223553865U discloses a novel forage planting and cultivation rack, including four sets of vertical rods, with multiple layers of placement plates between the vertical rods. A limiting component is provided at the upper end of the placement plate, and a cultivation box is installed inside the limiting component. A uniform spraying structure is provided at the rear end of the placement plate. This device can automatically and uniformly irrigate the forage, improving the labor intensity of manual watering to a certain extent. However, the device still has the following shortcomings: First, the sprinkler irrigation method easily causes water accumulation on the surface of the substrate, affecting the aeration of seeds in the early stage of germination. For forage grasses such as gramineous grasses, which have high requirements for rhizosphere aeration, sprinkler irrigation often leads to seed rot or uneven germination. Second, there is a lack of differentiated temperature and humidity control between the multi-layer structure. Seedlings at different developmental stages share the same temperature and humidity conditions, which cannot meet the differentiated environmental requirements of forage grasses at different growth stages. Third, light resources are unevenly distributed in the multi-layer structure. Seedlings in the lower layer are in a weak light environment for a long time, resulting in serious etiolation and making it difficult to guarantee seedling quality.

[0004] For example, Chinese utility model patent CN221058992U discloses a seedling cultivation box for forage planting, which adopts a detachable and assembleable two-box structure for easy internal cleaning and maintenance. However, this device is still relatively crude in terms of comprehensive regulation of environmental factors, lacking fine control over key parameters such as light spectrum, rhizosphere dissolved oxygen, and substrate moisture distribution, making it difficult to maximize the growth potential of forage seedlings.

[0005] Some existing technologies also employ hydroponics or aeroponics to cultivate forage seedlings. For example, CN111248079A discloses a staged hydroponic forage cultivation device and method. However, purely hydroponic methods face the risk of root hypoxia and root rot during the forage seedling stage. In particular, forage seedlings have fine roots that are extremely sensitive to the dissolved oxygen content in the nutrient solution. Insufficient dissolved oxygen can easily lead to root browning and rot.

[0006] In summary, how to provide equipment for forage seedling cultivation that can simultaneously solve problems such as rhizosphere oxygen supply, precise temperature and humidity distribution, and efficient light energy utilization is a technical problem that urgently needs to be solved by those skilled in the art. In other words, there is an urgent need for a cultivation box that can simulate the natural germination ecological conditions of forage and achieve synergistic optimization of the rhizosphere and canopy environments. Summary of the Invention

[0007] Based on the problems existing in the above-mentioned background technology, the present invention proposes a cultivation box for forage seedling cultivation, which solves the problems of insufficient rhizosphere oxygen supply leading to root rot, uneven temperature and humidity distribution in multi-layered structures, and large differences in seedling quality caused by the gradual attenuation of light resources in existing forage seedling cultivation devices.

[0008] The embodiments of the present invention are implemented as follows: The forage seedling cultivation box provided by this invention includes a main body, an autonomous temperature and humidity control system, an intelligent lighting system, a circulating irrigation system, and a control system. The main body consists of an outer insulation layer, an inner wall, and thermal insulation material, with a sealed door on the front. Internally, vertically arranged layers form a support structure, with each layer containing a retractable seedling tray with ventilation and drainage holes at the bottom. The autonomous temperature and humidity control system includes a temperature and humidity controller and electrically connected heating elements, a semiconductor cooling and heating module, a humidifying nozzle array, and temperature and humidity sensors; the heating elements, humidifying nozzle array, and temperature and humidity sensors are located on the inner wall, while the semiconductor cooling and heating module and temperature and humidity controller are located on the outside of the box. The intelligent lighting system includes multiple lighting components, each containing an LED spectral matrix, an adjustable light quality driver, and a light sensor array. The circulating irrigation system includes a nutrient solution tank, drip irrigation pipes, a circulating pump, a dissolved oxygen sensor, and a nutrient solution concentration sensor. The control system includes an intelligent control panel and a microprocessor, which is electrically connected to all actuators and sensors.

[0009] The core technical problem addressed by this solution is how to integrate temperature, humidity, light, water and fertilizer supply, and root management into a unified and coordinated control framework to avoid coupling interference between subsystems. In existing technologies, heat generated by light can interfere with temperature control, and changes in irrigation volume can affect rhizosphere oxygen content, but these correlations are not monitored and compensated for in real time. This invention uses a microprocessor as the central hub, integrating the temperature and humidity controller, the adjustable light quality driver, and the circulation pump into a closed-loop feedback network. This allows the temperature and humidity controller to immediately instruct the semiconductor cooling and heating module to activate cooling when the LED spectral matrix increases light intensity, causing a rise in the chamber temperature. When the irrigation circulation pump starts to increase liquid supply, the dissolved oxygen sensor monitors and provides feedback in real time, and the microprocessor can adjust the circulation pump speed or oxygenation strategy as needed. Simultaneously, the pull-out design of the support layer and seedling tray facilitates operation, and the breathable drainage holes ensure air exchange in the substrate.

[0010] This invention constructs a five-in-one synergistic control platform integrating light, temperature, water, air, and fertilizer, providing a complete hardware foundation and system architecture for the subsequent implementation of various refined features. Experiments show that after using this cultivation box, the germination rate of forage grass can be stabilized at over 95%, and the uniformity of seedlings is significantly higher than that of existing devices.

[0011] Furthermore, multiple mounting slots are vertically spaced along the inner surface of the inner chamber wall. Each slot contains a graphene heat exchanger strip as a heating element. These strips are connected to the heat exchange surface of the semiconductor cooling and heating module via flexible conductive tape, creating a temperature gradient field that decreases from top to bottom within the chamber. This design is based on the extremely high in-plane thermal conductivity of graphene (approximately 5300 W / m·K) and the rapid response characteristics of the semiconductor cooling and heating module. By connecting graphene heat exchangers of different heights to the semiconductor cooling and heating module via flexible conductive tapes of different lengths, the upper heat exchanger strips receive more heat than the lower ones due to differences in thermal resistance and the vertical temperature distribution within the module itself. This naturally creates a stable gradient with higher temperatures at the top and lower temperatures at the bottom. This gradient eliminates the need for multiple independent temperature control devices. Biological research indicates that the optimal temperature for forage seed germination is 20–25℃, gradually decreasing to 18–20℃ during the seedling stage and 16–18℃ during the root development stage. The temperature gradient set in this scheme (e.g., 22℃→18℃→16℃) perfectly matches the physiological requirements of forage seedling cultivation.

[0012] This invention achieves a zoned cultivation model of "germination in the upper zone, hardening in the middle zone, and root strengthening in the lower zone" within a single box. Users can move the seedling trays between different levels according to the seedling growth progress, eliminating the need for multiple devices and significantly reducing equipment costs and energy consumption. Simultaneously, the temperature gradient effectively suppresses condensation in the lower space, reducing the occurrence of diseases.

[0013] Furthermore, the seedling tray includes a tray bottom plate, tray side walls, and a biomimetic capillary permeation layer disposed above the tray bottom plate. The tray bottom plate is made of porous ceramic plate or sintered glass frosted plate, with uniformly distributed air and water permeability holes in a honeycomb pattern. The biomimetic capillary permeation layer is a porous elastomer formed by the composite cross-linking of plant fibers and sodium alginate, with a thickness of 8-15 mm, a porosity of 65%-80%, and a compression resilience of not less than 90%.

[0014] Traditional non-woven fabric or plastic drip trays suffer from discontinuous capillary action and uneven water and fertilizer distribution. The biomimetic capillary permeation layer utilizes a cross-linked network of sodium alginate and plant fibers to form a microporous structure similar to the hydrophobic-hydrophilic balance of the root surface, resulting in a significant capillary effect. When nutrient solution from the drip irrigation system soaks into this permeation layer from below, the liquid diffuses evenly to the surroundings and upwards through capillary action, ensuring uniform humidity across the entire tray surface. The porous ceramic base provides rigid support while ensuring gas exchange between the root zone and the underlying air through numerous pores. The honeycomb-shaped arrangement of the drainage holes prevents localized water accumulation.

[0015] During seed germination, the substrate surface does not accumulate water, reducing the mold rate by more than 70%; high porosity ensures sufficient oxygen exchange in the rhizosphere, significantly improving germination potential; and a compression rebound rate of over 90% ensures that the permeable layer can maintain a stable pore structure after multiple seed pressing and transplanting operations, with a service life of more than 20 seedling cycles.

[0016] Furthermore, the circulating irrigation system also includes a Venturi jet microbubble aeration device, which includes a Venturi tube connected in series between the outlet of the circulating pump and the drip irrigation pipeline, an air inlet pipe communicating with the throat of the Venturi tube, and an air filter installed at the inlet end of the air inlet pipe. The Venturi tube is composed of a constriction section, a throat, and a diffuser section connected in sequence. The inner diameter of the throat is 1 / 5 to 1 / 3 of the inner diameter of the inlet of the constriction section. At least one air intake hole is opened on the wall of the throat, and the air intake hole communicates with the outside atmosphere through the air inlet pipe. When the circulating pump drives the nutrient solution to flow through the Venturi tube, the flow velocity at the throat increases sharply and the pressure drops sharply to negative pressure. Outside air is drawn in through the air inlet pipe and broken into microbubbles with a diameter of 20 to 80 μm under the strong shearing action of the high-speed liquid flow, forming a gas-liquid mixture that enters the drip irrigation pipeline. The dissolved oxygen sensor monitors the dissolved oxygen concentration in the nutrient solution tank in real time and feeds it back to the microprocessor. The microprocessor adjusts the speed of the circulating pump according to the concentration value to control the air intake and bubble generation rate.

[0017] The basic principle of the Venturi jet microbubble aeration device is as follows: When the nutrient solution enters the contraction section of the Venturi tube at a certain flow rate (usually 1.5~3.0 m / s), the flow cross-section gradually decreases, and according to Bernoulli's equation, the flow velocity increases while the static pressure decreases. At the throat, where the cross-section is the smallest, the flow velocity reaches its maximum value, and the static pressure drops to a negative pressure value below atmospheric pressure (usually -20~-50 kPa). This negative pressure continuously draws in outside air through the suction port and inlet pipe. Under the strong turbulent shearing action of the high-speed liquid flow, the drawn-in air is torn and broken into a large number of micron-sized bubbles (20~80 μm). These microbubbles are uniformly dispersed in the nutrient solution, forming a milky white gas-liquid mixture. Subsequently, the mixture enters the diffusion section, where the flow velocity decreases and the pressure recovers. Under the pressure, the microbubbles are further compressed and stabilized. Compared with traditional aeration stones or labyrinth gas-liquid exchangers, Venturi jet aeration has the following hydrodynamic advantages: First, it has no moving parts, eliminating mechanical wear and clogging issues, resulting in extremely high long-term operational reliability; Second, it features small bubble size (20~80μm). According to Stokes' law, the bubble's rising velocity is proportional to the square of its diameter, and microbubbles can remain in water for tens of seconds to several minutes, making the oxygen transfer efficiency 20~50 times that of millimeter-sized bubbles (2~5mm in diameter); Third, it boasts a huge gas-liquid contact surface area—the total surface area of ​​microbubbles in each liter of nutrient solution can reach 5000~8000cm², far exceeding the 200~300cm² of labyrinth structures; Fourth, it has high energy utilization efficiency. The Venturi tube itself consumes no additional power, relying solely on the existing head of the circulating pump for operation, and under typical operating conditions, the aeration energy consumption is only 1 / 3 of that of the aeration stone method.

[0018] The microprocessor uses a PID algorithm to adjust the speed of the circulation pump based on the real-time dissolved oxygen concentration feedback from the sensor. When the dissolved oxygen concentration is below a set threshold (e.g., 6.5 mg / L), the microprocessor increases the circulation pump speed, increasing the throat flow rate, thereby enhancing negative pressure and air intake, and generating more microbubbles. When the concentration is too high (>8.5 mg / L), the speed is reduced to avoid excessive bubbles causing root zone air resistance. The air filter (0.22 μm pore size) effectively traps airborne fungal spores and bacteria, preventing contamination inside the chamber.

[0019] The beneficial effects are as follows: First, under standard operating conditions (circulating pump flow rate 8L / min, Venturi tube throat diameter 3mm), the dissolved oxygen concentration in the nutrient solution can be increased from 4.5mg / L to 7.8mg / L within 15 minutes and maintained stably at this level during subsequent operation, fully meeting the needs of forage grass roots for a high-oxygen environment (threshold 4.0mg / L), further reducing the incidence of root rot to below 1%. Second, when the microbubbles reach the seedling root zone, some bubbles adhere to the surface of the root hairs, forming a "microbubble rhizosphere layer." This layer not only provides sufficient oxygen but also inhibits the reproduction of anaerobic pathogens. Third, this device does not require an external air source or air compressor; it can operate using only the existing energy of the circulating pump, reducing the overall energy consumption of the cultivation box by 55% to 70% compared to traditional aeration methods. Fourth, with no moving parts and easily clogged micropores, the maintenance cycle is longer than 6 months, requiring only periodic cleaning of the air filter.

[0020] Furthermore, a mechanical lifting aerial root pruning device is provided at the bottom of the seedling tray (202). This device includes a guide fixedly installed below the seedling tray, a sliding lifting plate, heating wire rings fixed to the lifting plate and aligned with each ventilation and drainage hole, and a miniature electric push rod connecting the lifting plate to the tray bottom plate. The top of the guide shaft is fixedly connected to the bearing layer, and the bottom is fixedly connected to the inner wall of the box via a fixing block. The heating wire rings are connected to a pulse heating controller via flexible wires, and the miniature electric push rod and the pulse heating controller are electrically connected to a microprocessor. The lighting assembly is located below the lifting plate.

[0021] The principle of this scheme is based on the "heat-induced root control" technology in plant physiology. When the root tips of the forage seedlings emerge from the aeration and drainage holes, a microprocessor controls a miniature electric push rod to move the lifting plate upwards, causing a heating wire ring to surround the emerging root tip. Subsequently, a pulse heating controller applies a momentary current (0.3-0.8 seconds) to the heating wire ring, raising its temperature to 180-220°C, instantly severing the root tip and forming a carbonized sealing layer at the cut. This sealing layer prevents pathogen invasion and sap leakage, and simultaneously acts as a mild stress signal, triggering compensatory root growth and inducing the sprouting of numerous lateral roots above the cut. The guide mechanism employs a structure of four guide shafts and a fixing block, ensuring the smooth movement and centering accuracy of the lifting plate. The lighting components are located below the lifting plate, avoiding the influence of heat sources on the uniformity of light illumination. Compared with traditional air pruning, the incidence of root rot after thermal cutting of root tips decreased from 12% to below 2%; the number of lateral roots increased by 40% to 50%; the root-to-shoot ratio increased to over 0.75; and seedlings recovered to normal growth within 2 hours after heat stimulation, with no visible stress. Furthermore, the device is compact in structure and precise in control, making it suitable for unmanned operation in factory-scale forage seedling production.

[0022] Furthermore, the drip irrigation pipeline is arranged in a wavy or serpentine pattern along the length of the seedling tray below the biomimetic capillary permeation layer. Multiple micropores are evenly distributed on the pipe wall, with the pore size of each micropore increasing in a stepped manner from the end closer to the circulating pump to the end farther from the circulating pump. The pore size distribution satisfies the following: d ( i )= d 0 ×(1 +k×i / L ), in d ( i ) is the first i The orifice diameter of the drip irrigation pipeline is given by L, the total length of the drip irrigation pipeline is given by k, the correction coefficient is given by d0, and the orifice diameter at the starting end is given by d0, so as to achieve the gradual infiltration of irrigation water.

[0023] The principle of this scheme is based on the fluid mechanics principle of friction loss compensation. In straight, uniform-aperture drip irrigation pipes, due to friction resistance, the inlet end has high pressure and high water output, while the distal end has low pressure and low water output, resulting in uneven irrigation. This invention establishes a friction pressure distribution model and derives an optimal compensation function for increasing aperture along the flow path. This ensures that despite pressure differences at various points, increasing the distal aperture reduces local resistance, thereby making the outflow rate of each micro-perforation in the entire pipeline more uniform. The wavy or serpentine layout further increases the horizontal coverage of the drip irrigation pipe at the bottom of the tray, eliminating the "dry strips" that may occur with straight layouts. After adopting this gradient infiltration structure, the difference in substrate moisture content between any two diagonal positions in the seedling tray is reduced from 38% in traditional uniform-aperture pipes to less than 6%, the uniformity coefficient (CV value) of forage emergence decreases from 46% to below 22%, and the proportion of robust seedlings increases by 65%.

[0024] Furthermore, each lighting component is fixedly connected to the inner wall of the enclosure via a transparent mounting block, and the LED spectral matrix and adjustable light quality driver are mounted on the transparent mounting block. The LED spectral matrix consists of red, blue, green, and white LEDs driven independently in a multi-channel manner. The adjustable light quality driver has a built-in spectral database that stores standard spectral curves required for pasture seedlings at three different stages: germination, seedling, and growth. The light sensor array collects illuminance and spectral distribution data in real time, and the microprocessor dynamically adjusts the output spectrum after comparison. This solution is based on photomorphogenesis theory and feedback control technology. Different wavelengths of light have different regulatory effects on forage growth and development: red light (660nm) promotes seed germination and stem elongation, blue light (450nm) inhibits excessive growth and promotes chlorophyll synthesis, and green light (540nm) can penetrate the canopy to improve the photosynthetic efficiency of lower leaves. This invention pre-sets the optimal spectral curves required for each stage of forage growth in a database, acquires the actual spectral distribution within the enclosure through a light sensor array, and adjusts the driving current ratio of each color LED after calculating the deviation, ensuring that the spectrum within the enclosure always closely approximates the target curve. A transparent mounting block ensures unobstructed light path. The lighting components are positioned below the lifting plate, preventing collisions with the lighting components when the lifting plate moves upwards. This achieves a leap from "experience-based supplemental lighting" to "quantitative, staged light formulation," achieving a photosynthetically effective radiation uniformity of over 90%, saving approximately 22% energy compared to fixed-spectrum LED lights, increasing forage chlorophyll content by 31%, and improving seedling vigor index by 56%.

[0025] Furthermore, the sealed door is a double-layered, hollow tempered glass door, with inert gas filling the space between the two layers of glass, and magnetic sealing strips embedded around the door frame. A removable sampling operation window is embedded in the center of the door. An adjustable fresh air vent is located at the back of the chamber, equipped with an air filter and an electric damper, which is electrically connected to the microprocessor. The double-layered hollow inert gas filling reduces the heat transfer coefficient to below 2.0 W / m²·K, effectively insulating the chamber; the magnetic sealing strip eliminates the risk of leakage due to aging of traditional rubber strips; the sampling operation window allows observation and sampling without opening the entire door, maximizing the stability of the internal environment. The high-efficiency filter of the fresh air vent intercepts PM2.5 and larger particles and fungal spores, and the electric damper automatically adjusts its opening based on CO2 sensor data, ensuring the carbon dioxide concentration (380~550 ppm) required for photosynthesis. Compared to traditional fully open door designs, this reduces heat loss and humidity disturbance by 85%; the number of pathogenic bacteria colonies inside the chamber is reduced by two orders of magnitude; and the CO2 concentration remains within a suitable range.

[0026] Furthermore, the control system also includes a remote communication module and an audible and visual alarm. The remote communication module can be a Wi-Fi, Bluetooth, or 4G / 5G module, and the audible and visual alarm is located on the intelligent control panel.

[0027] The microprocessor uploads data from various sensors to a cloud server in real time or pushes it directly to the user's mobile app. When any parameter exceeds a preset threshold, the microprocessor immediately activates an audible and visual alarm and pushes the alarm information to the user's terminal via a remote communication module. Users can view data, adjust parameters, or manually deactivate the alarm remotely. This enables unattended management, allowing a single person to manage dozens of cultivation boxes simultaneously, reducing labor costs by 70%. Alarm response time is reduced from several hours of manual inspection to less than 30 seconds, effectively preventing large-scale seedling losses due to equipment failure.

[0028] Furthermore, each load-bearing layer includes two horizontally spaced fixing strips, with the length of the fixing strips pointing towards the sealing door. The outer side of the fixing strips is fixedly connected to the inner walls of the main body of the box, and sliding grooves are provided on the sides of the fixing strips. Two sliders that slide in conjunction with the sliding grooves are provided on the side wall of the seedling tray.

[0029] A simple steel or aluminum alloy fixing strip is used, with a sliding groove machined or assembled on its inner side, forming a low-friction linear motion pair with a slider (such as PTFE material) on the side wall of the seedling tray. This structure eliminates the need for complex guide rails, is low-cost, and easy to clean. The pull-out direction faces the sealed door for easy operation.

[0030] Compared with existing forage seedling raising devices, the beneficial effects of this invention are: 1. This invention creates a gradient field with decreasing temperature from top to bottom within a box by arranging graphene heat exchange strips in layers along the vertical direction and connecting them with a semiconductor cooling and heating module. This achieves zoned cultivation of "germination in the upper zone, hardening in the middle zone, and root strengthening in the lower zone", significantly reducing equipment costs and energy consumption, and effectively suppressing condensation in the lower layer.

[0031] 2. This invention uses a biomimetic capillary permeation layer composed of plant fiber and sodium alginate, combined with a honeycomb porous base plate, to achieve uniform diffusion of irrigation nutrient solution and sufficient aeration of the root zone, thereby reducing seed mold rate and improving seed germination rate.

[0032] 3. The invention features a unique mechanical lifting thermal cutting aerial root pruning device that instantly burns off the protruding root tips and seals the cut by using an electric heating wire ring, significantly reducing the incidence of root rot and increasing the number of lateral roots and transplant survival rate.

[0033] 4. The present invention adopts a gradient distribution of the pore size along the drip irrigation pipeline and a wavy / serpentine layout, which reduces the difference in substrate moisture content throughout the seedling tray and significantly improves the uniformity of seedling emergence.

[0034] 5. This invention integrates a four-color LED spectral matrix and a light quality adjustable driver, and achieves adaptive closed-loop control of the spectrum through feedback from the light sensor array, thereby improving the uniformity of photosynthetically effective radiation. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and other objects, features, and advantages of the present invention will become clearer through the accompanying drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual dimensions; the focus is on illustrating the main points of the invention.

[0036] Figure 1 This is a front view schematic diagram of a cultivation box for forage seedlings.

[0037] Figure 2 This is a schematic diagram of the rear view structure of a cultivation box for forage seedlings.

[0038] Figure 3 This is a cross-sectional structural diagram of the main body of the box.

[0039] Figure 4 This is a cross-sectional view of a seedling tray.

[0040] Figure 5 This is a schematic diagram of a recirculating irrigation system.

[0041] Figure 6 This is a schematic diagram of a Venturi jet microbubble aeration device.

[0042] Figure 7 This is a block diagram illustrating the principle of an intelligent lighting system.

[0043] Figure 8 This is a block diagram of the control system.

[0044] Figure 9 This is a schematic diagram of a mechanical lifting aerial root trimming device.

[0045] Figure 10 This is a schematic diagram of the principle of an autonomous temperature and humidity control system.

[0046] In the diagram: 1. Main body of the box; 101. Outer insulation layer; 102. Inner box wall; 103. Thermal insulation material; 104. Sealed door; 106. Magnetic sealing strip; 107. Sampling operation window; 108. Fresh air vent; 109. Air filter; 110. Electric damper; 201. Load-bearing layer; 202. Seedling tray; 203. Breathable and permeable holes; 204. Tray bottom plate; 205. Tray side wall; 206. Bionic capillary permeation layer; 207. Slider; 208. Sliding groove; 3. Autonomous temperature and humidity control system; 301. Heating element; 302. Semiconductor cooling and heating module; 303. Humidifying nozzle array; 304. Temperature and humidity controller; 305. Temperature and humidity sensor; 307. Mounting slot; 4. Intelligent lighting system; 40. Lighting component; 401. LED spectral matrix 402. Light quality adjustable driver; 403. Light sensor array; 5. Circulating irrigation system; 501. Nutrient solution storage tank; 502. Drip irrigation pipeline; 503. Circulating pump; 504. Dissolved oxygen sensor; 505. Nutrient solution concentration sensor; 506. Venturi jet microbubble oxygenation device; 510. Venturi tube; 511. Air inlet pipe; 512. Air filter; 513. Contraction section; 514. Throat; 515. Diffusion section; 516. Inhalation hole; 509. Micro-permeation hole; 6. Control system; 601. Intelligent control panel; 602. Microprocessor; 603. Remote communication module; 606. Audible and visual alarm; 8. Mechanical lifting aerial root pruning device; 803. Miniature electric push rod; 804. Guide component; 805. Lifting plate; 806. Heating wire ring. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] Example 1, such as Figures 1-9As shown in the figure, this embodiment provides a cultivation box for forage seedlings. The cultivation box includes a main body 1, an autonomous temperature and humidity control system 3, an intelligent lighting system 4, a circulating irrigation system 5, and a control system 6.

[0051] like Figure 1 and Figure 3 As shown, the main body 1 of the enclosure consists of an outer insulation layer 101, an inner wall 102, and thermal insulation material 103 filled between the outer insulation layer and the inner wall. In this embodiment, the outer insulation layer 101 is made of 0.5mm thick galvanized steel plate, the inner wall 102 is made of 1.0mm thick 304 stainless steel plate, and the thermal insulation material 103 is polyurethane rigid foam (thickness 50mm, thermal conductivity ≤0.022W / m·K). A sealed door 104 is provided on the front side of the main body 1. The sealed door 104 is a double-layer hollow tempered glass door (the gap between the two layers of glass is 12mm, filled with argon gas), and a magnetic sealing strip 106 is embedded around the door frame. A detachable sampling operation window 107 (diameter 150mm, material is high-transparency polycarbonate) is embedded in the middle of the sealed door 104, allowing operators to observe the growth of seedlings or take small samples without opening the entire door, thus maintaining the stability of the environment inside the enclosure to the greatest extent.

[0052] like Figure 2 As shown, a set of fresh air vents 108 is provided on the back of the main body 1 of the box. A HEPA-grade air filter 109 (filtration efficiency ≥99.97% at 0.3μm) and an electric damper 110 are installed at the fresh air vents 108.

[0053] like Figure 1 and Figure 4 As shown, the interior of the main body 1 has three vertically arranged load-bearing layers 201. Each load-bearing layer 201 includes two horizontally spaced aluminum alloy fixing strips, with the length of the fixing strips facing the sealing door 104. The outer sides of the two fixing strips are fixedly connected to the inner walls 102 on both sides of the main body 1 by screws, and a sliding groove 208 (T-shaped cross-section) is provided on the inner side of each fixing strip. A slider 207 (made of polytetrafluoroethylene) is fixed on each side wall 205 of the seedling tray 202. The slider 207 slides in conjunction with the sliding groove 208, allowing the seedling tray 202 to be smoothly pulled towards the sealing door 104.

[0054] The principle behind this pull-out design is that polytetrafluoroethylene (PTFE) has an extremely low coefficient of friction (0.04~0.10) and excellent corrosion resistance, preventing rusting or jamming in high-humidity environments. The clearance between the slider 207 and the sliding groove 208 is controlled at 0.2~0.5mm, ensuring smooth pulling while preventing the seedling trays from shaking under load. The pull-out direction faces the sealed door 104, allowing operators to directly pull out any layer of seedling trays for sowing, observation, sampling, or transplanting after opening the door, without needing to put their hands inside the box, thus avoiding the risk of contamination and interference with seedlings in other layers.

[0055] like Figure 4 As shown, the seedling tray 202 includes a tray bottom plate 204, tray side walls 205 surrounding the tray bottom plate, and a biomimetic capillary permeation layer 206 disposed above the tray bottom plate 204. The tray bottom plate 204 is made of porous alumina ceramic plate (thickness 3mm, bending strength ≥250MPa), on which hexagonal honeycomb-shaped air and water permeability holes 203 are evenly distributed, with a hole diameter of 2mm and a hole spacing of 5mm. This honeycomb arrangement maximizes the porosity (approximately 45%) while ensuring structural strength, providing sufficient channels for gas exchange in the root zone. The biomimetic capillary permeation layer 206 is a porous elastomer made of ramie short fibers (length 3~5mm) and sodium alginate (crosslinking agent is glutaraldehyde) by freeze-drying, with a thickness of 12mm, a porosity of 75%, and a compression rebound rate that remains at 92% after 200 cycles of testing.

[0056] The working principle of the biomimetic capillary permeation layer 206: The carboxyl groups on the sodium alginate molecular chain and the hydroxyl groups on the plant fiber surface form a three-dimensional network structure under the action of a cross-linking agent. The micropore diameter of this network is controlled between 50 and 200 μm, matching the scale of plant root hairs. Due to the hydrophilicity of sodium alginate and the existence of hydrophobic regions on the plant fiber surface, this network exhibits an alternating "hydrophobic-hydrophilic" wetting pattern, thereby generating a strong capillary effect (capillary rise height can reach over 80 mm). When the nutrient solution in the drip irrigation pipe 502 soaks into this permeation layer from below, the liquid rapidly spreads horizontally and is transported vertically within the permeation layer through capillary action, resulting in a highly uniform humidity distribution across the entire tray surface. The porous ceramic base plate 204 not only provides rigid support for the permeation layer, but its own open structure also allows free exchange of air between the root zone and the space beneath the tray, preventing oxygen deficiency caused by water accumulation. High porosity (75%) and excellent compression resilience (92%) ensure that the permeable layer is not compacted during sowing and transplanting, and its service life exceeds 20 seedling cycles.

[0057] like Figure 1 , Figure 2 , Figure 3 and Figure 10As shown, the autonomous temperature and humidity control system 3 includes a temperature and humidity controller 304, a heating element 301, a semiconductor cooling and heating module 302, a humidifying nozzle array 303, and a temperature and humidity sensor 305. Three mounting slots 307 are vertically spaced on the inner surface of the inner wall 102 (corresponding to the height positions of the upper, middle, and lower support layers 201, respectively). Each mounting slot 307 contains a heating element 301, which is a graphene heat exchange strip (dimensions: 20mm wide, 2mm thick, 300mm long, in-plane thermal conductivity ≥1500W / m·K). Each heating element 301 is connected to the heat exchange surface of the semiconductor cooling and heating module 302 located on the back of the main body 1 of the chamber via flexible conductive tapes (copper braided tape, with an outer silicone insulation layer) of different lengths. The humidifying nozzle array 303 consists of four ultrasonic atomizing nozzles (operating frequency 1.7MHz, atomization volume 300mL / h), embedded on the left and right sides of the inner wall 102. The temperature and humidity sensor 305 is installed in the middle of the inner wall 102 and is a digital integrated temperature and humidity sensor (accuracy ±0.3℃, ±2%RH). The temperature and humidity controller 304 and the semiconductor cooling and heating module 302 are both located on the outside of the main body 1 (on the back bracket) to reduce the internal heat load and facilitate heat dissipation.

[0058] The temperature gradient formation principle of this system: The graphene heat exchange strip has an extremely high in-plane thermal conductivity, enabling it to quickly and evenly distribute the heat or cold transferred from the semiconductor cooling and heating module 302 via the flexible heat exchange strip within the area of ​​the mounting slot 307. Because the flexible heat exchange strips connected to the upper, middle, and lower heating elements 301 have different lengths (the upper layer is the shortest, the lower layer the longest), and the heat exchange strip itself has a certain thermal resistance, the upper heat exchange strip receives the most heat, and the lower layer receives the least. Simultaneously, when the semiconductor cooling and heating module 302 is working, its heat exchange surface also exhibits a vertical temperature distribution (the temperature at the top of the module is slightly higher than the bottom). The combination of these two factors naturally creates a temperature gradient inside the enclosure: a higher temperature at the top, a moderate temperature in the middle, and a lower temperature at the bottom. In this embodiment, this is set as 22℃ (upper germination zone) → 18℃ (middle hardening zone) → 16℃ (lower root strengthening zone). Biological research shows that the optimal temperature for forage seed germination is 20-25℃, at which enzyme activity is highest and the radicle breaks through the seed coat most quickly. Appropriately lowering the temperature during the seedling stage can inhibit excessive growth of the above-ground parts and promote root development. Further cooling during the root-strengthening stage can induce deeper root growth and increase the root-to-shoot ratio. The temperature gradient in this scheme closely matches the physiological needs of common forage grasses such as alfalfa and ryegrass.

[0059] The humidifying nozzle array 303 uses ultrasonic atomization to atomize water into dry mist particles of 1~5μm, preventing the formation of a water film on the leaf surface and avoiding the mold and rot caused by traditional spraying. The temperature and humidity controller 304 uses a PID algorithm to dynamically adjust the power of the semiconductor cooling and heating module 302, the on / off ratio of the heating element 301, and the spraying time of the humidifying nozzle array 303 based on the feedback signal from the temperature and humidity sensor 305, so that the environmental parameters inside the chamber are stabilized within the set values ​​of ±0.5℃ and ±3%RH.

[0060] like Figure 1 and Figure 7 As shown, the intelligent lighting system 4 includes three lighting components 40, which are respectively installed on the top wall of the main body 1 and below each load-bearing layer 201. Each lighting component 40 is fixedly connected to the inner wall 102 via a transparent mounting block (acrylic material, 5mm thick, light transmittance ≥92%). The lighting component 40 includes an LED spectrum matrix 401, a light quality adjustable driver 402, and a light sensor array 403. The LED spectrum matrix 401 consists of red (660nm), blue (450nm), green (540nm), and white (400~700nm) LED beads arranged in a 16×16 array with a bead spacing of 25mm. The driving current of each group of beads can be adjusted independently. The light quality adjustable driver 402 integrates an ARM Cortex-M0 processor and a four-channel constant current drive circuit, storing standard spectral curves for alfalfa during germination (R / B=1.2:1, light intensity 80 μmol·m⁻²·s⁻¹), seedling stage (R / B=0.8:1, light intensity 180 μmol·m⁻²·s⁻¹), and growth stage (R / G / B=5:2:3, light intensity 350 μmol·m⁻²·s⁻¹). The light sensor array 403 consists of six miniature spectral sensors distributed in various corners of the enclosure (each sensor can detect irradiance in 10 bands within the 400~700nm range).

[0061] The light sensor array 403 collects illuminance and spectral distribution data at various locations in real time and transmits it to the microprocessor 602 via the I²C bus. The microprocessor 602 compares the actual spectral curve with the standard spectral curve corresponding to the current growth stage band by band, calculating the correction coefficient for the driving current of each color LED (for example, if red light is found to be less than 10%, the current in the red light channel is increased by 10%). Subsequently, the PWM signal controls the light quality adjustable driver 402 to adjust the duty cycle of the four-color LEDs, ensuring that the uniformity of photosynthetically effective radiation within the enclosure reaches over 90%. The use of a transparent mounting block ensures unobstructed light path and facilitates disassembly and maintenance. The principle of adjustable light quality is based on photomorphogenesis theory: red light regulates seed germination and stem elongation through the phytochrome system; blue light inhibits hypocotyl elongation and promotes chlorophyll synthesis through cryptochrome; green light can penetrate the canopy to reach the lower leaves, improving the overall photosynthetic efficiency of the plant. This scheme dynamically adjusts the spectrum according to different growth stages, achieving efficient utilization of light energy.

[0062] like Figure 1 , Figure 4 and Figure 5 As shown, the circulating irrigation system 5 includes a nutrient solution storage tank 501 (15L capacity, located at the bottom of the tank, made of food-grade polypropylene), drip irrigation pipeline 502, a circulating pump 503 (a miniature magnetic pump, rated flow rate 8L / min, head 4m), a dissolved oxygen sensor 504 (polarographic type), and a nutrient solution concentration sensor 505 (conductivity probe). The circulating irrigation system 5 also includes a Venturi jet microbubble aeration device 506.

[0063] The Venturi jet microbubble aeration device 506 includes a Venturi tube 510 connected in series between the outlet of the circulating pump 503 and the drip irrigation pipeline 502, an air inlet pipe 511 communicating with the throat of the Venturi tube 510, and an air filter 512 (0.22μm hydrophobic PTFE filter membrane) installed at the inlet end of the air inlet pipe 511. The Venturi tube 510 is injection molded from PVDF material and is composed of a contraction section 513, a throat 514, and a diffuser section 515 connected in sequence. The inlet inner diameter of the contraction section 513 is 10mm, the inner diameter of the throat 514 is 2.8mm (0.28 times the inlet inner diameter), the throat length is 6mm, the outlet inner diameter of the diffuser section 515 is 10mm, and the diffusion angle is 8°. Four air intake holes 516 with a diameter of 1.0mm are evenly opened on the circumference of the throat 514. The four air intake holes 516 converge into an annular air collection chamber, which is connected to the air inlet pipe 511.

[0064] The fluid dynamics principle of Venturi oxygenation: When the circulating pump 503 drives the nutrient solution into the contraction section 513 at a flow rate of approximately 2.2 m / s, the flow cross-section gradually decreases, and according to Bernoulli's equation, the flow velocity increases while the static pressure decreases. At the throat 514, where the cross-section is at its minimum, the flow velocity suddenly increases to approximately 28 m / s, and the static pressure drops to -35 kPa (relative to atmospheric pressure). This negative pressure continuously draws in outside air through the intake port 516 and the intake pipe 511. The drawn-in air is torn into numerous microbubbles with diameters of 20–80 μm by strong shear forces in the high-speed turbulence of the throat 514. These microbubbles are uniformly dispersed in the nutrient solution, forming a milky white gas-liquid mixture. Subsequently, the mixture enters the diffuser section 515, where the flow velocity decreases, the pressure recovers, and the microbubbles are further compressed and stabilized under pressure. Dissolved oxygen sensor 504 monitors the dissolved oxygen concentration in nutrient solution tank 501 in real time and feeds it back to microprocessor 602. Microprocessor 602 uses a PID algorithm to adjust the rotation speed of circulation pump 503 based on the concentration value: when the dissolved oxygen concentration is below 6.5 mg / L, the rotation speed is increased to enhance negative pressure and aeration; when the concentration is above 8.5 mg / L, the rotation speed is decreased to avoid excessive air bubbles causing root zone air resistance. In this embodiment, with a circulation pump flow rate of 8 L / min, the dissolved oxygen concentration in the nutrient solution can be increased from 4.5 mg / L to 7.8 mg / L within 15 minutes and maintained stably at this level.

[0065] like Figure 1 and Figure 9 As shown, a mechanical lifting aerial root trimming device 8 is provided at the bottom of the seedling tray 202. The device includes a guide 804 fixedly installed below the seedling tray 202, a lifting plate 805 slidably installed on the guide 804, an electric heating wire ring 806 fixed on the lifting plate 805 and arranged one-to-one with each air and water seepage hole 203, and a miniature electric push rod 803 connecting the lifting plate 805 and the tray bottom plate 204.

[0066] The guide component 804 includes four stainless steel guide shafts (5mm in diameter, 80mm in length, chrome-plated) and four aluminum alloy fixing blocks. The four guide shafts are arranged in a rectangle (the long side corresponds to the width of the seedling tray, and the short side corresponds to the length). The top of the guide shafts is fixedly connected to the lower surface of the fixing strip of the bearing layer 201 via threads, and the bottom of the guide shafts is fixedly connected to the inner box wall 102 via fixing blocks. The lifting plate 805 is made of aluminum alloy plate (3mm thick, anodized surface), with linear bearings installed at the four corners, allowing it to slide up and down along the guide shafts with a side clearance of ≤0.1mm. A heating wire ring 806 (nickel-chromium Cr20Ni80, wire diameter 0.2mm, inner diameter 2.2mm, height 2.5mm) is welded to the upper surface of the lifting plate 805 at a position directly opposite each ventilation and drainage hole 203. The heating wire ring 806 is connected to the pulse heating controller (installed on the back of the main body 1) via a high-temperature resistant silicone flexible wire (temperature resistant 250℃). The housing of the miniature electric actuator 803 (6mm stroke, 30N thrust, 2mm / s response speed) is fixed to the lower surface of the base plate 204, and the actuator head is hinged to the center of the lifting plate 805. Both the miniature electric actuator 803 and the pulse heating controller are electrically connected to the microprocessor 602. The lighting assembly 40 is installed approximately 15mm below the lifting plate 805 to ensure that the movement of the lifting plate does not interfere with the lighting.

[0067] like Figure 1 and Figure 8 As shown, the control system 6 includes an intelligent control panel 601 and an integrated microprocessor 602 (model: STM32F407, 168MHz). The intelligent control panel 601 is installed on the front right side of the main body 1, and features a 4.3-inch capacitive touchscreen display, an audible and visual alarm 606, and a USB data interface (for exporting historical data or importing new crop spectral curves). The microprocessor 602 is electrically connected to the temperature and humidity controller 304, the light quality adjustable driver 402, the circulation pump 503 driver, and various sensors via an RS485 bus. The control system 6 also includes a remote communication module 603 (ESP8266 Wi-Fi module), which communicates with the user's mobile APP via the MQTT protocol. Users can remotely view real-time data such as temperature, humidity, light intensity, dissolved oxygen, and nutrient solution concentration, receive over-limit alarm push notifications, and remotely modify setting parameters or manually perform aerial root pruning.

[0068] In this embodiment, the forage seedling cultivation box is used for raising alfalfa seedlings. Before sowing, alfalfa (variety WL168) seeds are disinfected with 0.1% potassium permanganate solution for 10 minutes, rinsed with clean water, and then evenly sown on the surface of the biomimetic capillary permeation layer 206 at a sowing density of about 800 seeds / m², and covered with a thin layer of vermiculite (3-5 mm thick). Set the seedling parameters using the intelligent control panel 601: During the germination period (days 1-4 after sowing), place the seedling trays on the upper layer, setting the temperature to 22℃, humidity to 85%, photoperiod to 16h light / 8h dark, and light intensity to 80μmol·m⁻²·s⁻¹; during the seedling stage (days 5-10), move the seedling trays to the middle layer, setting the temperature to 18℃, humidity to 75%, and light intensity to 180μmol·m⁻²·s⁻¹; during the root development stage (days 11-18), move the trays to the lower layer, setting the temperature to 16℃, humidity to 65%, and light intensity to 350μmol·m⁻²·s⁻¹. The circulating irrigation system 5 is activated every 2 hours, running for 5 minutes each time, using a 1 / 2 concentration Hogland nutrient solution (EC value 1.2mS / cm, pH 6.0). The Venturi jet microbubble aeration device 506 works synchronously with the circulating pump to maintain dissolved oxygen at 7.5±0.5mg / L.

[0069] The aerial root pruning procedure is performed once each on the 6th, 11th, and 16th days after sowing, 2 hours after the start of the photoperiod (when the seedlings are in an active metabolic state). Each pruning process is as follows: the microprocessor 602 first checks whether the relative humidity inside the box is below 65% (if it is above 65%, the operation is delayed to avoid moisture causing a short circuit in the heating wire), and then controls the micro electric push rod 803 to push the lifting plate 805 upward at a speed of 2mm / s, so that the heating wire ring 806 rises from the initial position (15mm from the lower surface of the tray bottom plate) to a position flush with the lower surface of the tray bottom plate. At this time, the root tip (extending length of about 3~6mm) extending out of the air and water seepage hole 203 is exactly in the center of the heating wire ring 806. The microprocessor 602 then sends a trigger signal to the pulse heating controller, which applies a 2.5A pulse current for 0.4 seconds to the heating wire ring 806. The heating wire ring 806 heats up to 190±5℃ within 0.3 seconds, instantly severing the root tip and forming a carbonized sealing layer approximately 0.1mm thick at the cut. After power is cut off, the heating wire ring 806 cools naturally to below 50℃ within 1 second. Finally, the microprocessor 602 controls the miniature electric push rod 803 to reset, and the lifting plate 805 descends to its initial position.

[0070] The formation of a carbonized sealing layer is the core advantage of thermal cutting: the instantaneous high temperature vaporizes water and denatures and coagulates proteins in root tip cells, forming an inert carbonized layer on the cut surface. This carbonized layer has three physiological functions: first, it acts as a physical barrier to prevent pathogens (such as Pythium and Fusarium) from invading the root tissue through the cut; second, it blocks the outflow of sap from the xylem vessels, reducing nutrient loss; and third, as a mild stress signal (rather than severe trauma), it induces a systemic defense response in the root system, promoting the germination of numerous lateral root primordia above the cut. Experiments have shown that within 24 hours after thermal cutting, lateral root primordia swelling can be observed 2-5 mm above the cut, and lateral roots emerge on the 5th day.

[0071] A seedling cultivation experiment was conducted on alfalfa using the cultivation box of this embodiment. A control group was set up using a traditional three-dimensional spray seedling rack (fixed spectrum LED, aeration stones, no aerial root pruning). Each treatment had three replicates, and 300 seeds were sown in each seedling tray. The results are as follows: germination rate: experimental group 97.2%, control group 78.6%; germination vigor (day 4): experimental group 86.5%, control group 51.3%; day 14: average seedling height 62mm, root length 88mm, root-to-shoot ratio 0.82 in the experimental group, compared to 71mm, 51mm, and 0.45 in the control group; root rot incidence: 0.9% in the experimental group, 15.3% in the control group; white root rate: 99% in the experimental group, brown root rate: 31% in the control group; survival rate 30 days after transplanting: 95.8% in the experimental group, 70.2% in the control group. The data show that this embodiment is significantly superior to existing technologies in terms of germination rate, root development, disease resistance, and transplant survival rate.

[0072] Example 2 differs from Example 1 in that the operating parameters of the Venturi jet microbubble aeration device 506 were adjusted for high oxygen-consuming forage varieties (such as oat grass, Avenasativa), and the triggering logic and thermal cutting parameters for aerial root trimming were optimized.

[0073] Oat grass seedlings have a high root oxygen requirement (critical dissolved oxygen concentration of 5.0 mg / L) and relatively thick roots (0.8-1.2 mm in diameter). To improve oxygen supply capacity, in this embodiment, the inner diameter of the throat 514 of the venturi tube 510 is adjusted to 3.2 mm (0.32 times the inner diameter of the inlet of the constriction section 513), and the rated flow rate of the circulation pump 503 is increased to 12 L / min. During operation, the microprocessor 602 sets the target dissolved oxygen value to 8.0 mg / L and adopts a variable gain PID control algorithm: when the dissolved oxygen concentration is below 7.0 mg / L, the circulation pump 503 runs at full speed; between 7.0 and 7.8 mg / L, the speed is linearly adjusted; and above 7.8 mg / L, it switches to a low-speed maintenance mode. Actual operating data shows that the system can increase the dissolved oxygen from 4.2 mg / L to 8.3 mg / L within 10 minutes, and the fluctuation range after stabilization is ±0.3 mg / L. The microbubbles have a diameter of 30-50 μm and a half-life of 120 seconds in the nutrient solution, which is much longer than that of conventional aeration bubbles (2-5 seconds).

[0074] The principle behind this parameter optimization is as follows: While a moderate increase in throat diameter (from 2.8 mm to 3.2 mm) reduces throat velocity (from 28 m / s to 22 m / s), it increases the flow area of ​​the inhalation pores, resulting in an approximately 40% increase in air intake. Simultaneously, the microbubble diameter slightly increases (from 20-80 μm to 30-60 μm), but the oxygen mass transfer coefficient of these microbubbles remains significantly higher than that of millimeter-sized bubbles. More importantly, larger-diameter microbubbles have a longer residence time in the root zone, making them more easily captured by root hairs and forming a "microbubble rhizosphere layer."

[0075] For the thicker roots of oat grass, this embodiment adjusts the thermal cutting parameters to: pulse current 3.0A, energizing time 0.6 seconds, and target temperature 205±5℃. This is because thicker root tips (0.8~1.2mm in diameter) require higher heat to be completely cut, and the carbonized sealing layer needs more thorough carbonization to form an effective barrier. However, the temperature should not exceed 220℃, otherwise it will damage the healthy tissue below the cut. The microprocessor 602 has a preset oat grass-specific pruning schedule: 5 days after sowing (when root tips begin to emerge), 9 days, and 14 days, with an average of 2~3 prunings per seedling. The pruning timing is not determined by fixed days, but rather by a miniature camera (optional) installed on the inner wall 102 combined with an image recognition algorithm. When more than 20% of the air and water perforations 203 are detected to have root tips extending ≥4mm, the pruning program is automatically triggered.

[0076] Oat grass was cultivated using this embodiment, and compared with the blank control group (alfalfa parameters) of Example 1. The results showed that when running with the optimized Venturi parameters, the dissolved oxygen concentration remained stable at 8.0±0.3 mg / L, and the root rot incidence rate was 0.5%; while when running with alfalfa parameters, the dissolved oxygen concentration could only be maintained at 6.2±0.5 mg / L, and the root rot incidence rate was 2.4%. After treatment with oat grass-specific pruning parameters (205℃, 0.6 seconds), the carbonized layer of the root tip cut was intact, with no black rot spread, and the number of lateral root sprouts increased by 52% compared to the unpruned group; however, when treated with alfalfa parameters (190℃, 0.4 seconds), due to insufficient heat, about 30% of the root tips were not completely severed, forming "stringy" semi-broken roots, which induced local infection. This indicates that the present invention achieves precise adaptation to different forage varieties through the programmability of the microprocessor 602, expanding the versatility of the cultivation box.

[0077] Example 3 focuses on illustrating the time-series coordinated control strategy of the intelligent lighting system 4 and the mechanical lifting aerial root pruning device 8, and the promoting effect of this strategy on the distribution of photosynthetic products and root development of forage seedlings.

[0078] Using Lolium multiflorum as an example, this variety is extremely sensitive to light quality during the seedling stage; too low a proportion of blue light can lead to severe etiolation. In this embodiment, a refined four-stage light formula was set for ryegrass based on the spectral database of the light quality tunable actuator 402: Germination induction period (0-48 hours after sowing): Dark conditions (simulating the dark environment of seeds in the soil), maintaining only a temperature of 22℃ and humidity of 90%, without turning on the LED spectral matrix 401, to induce uniform germination of the radicle.

[0079] Green light transition period (days 3-5): Spectral R / G / B = 3:5:2, total light intensity 120 μmol·m⁻²·s⁻¹. Principle: Green light has strong penetrating power, which can evenly illuminate the entire seedbed, avoiding the "uneven crown" phenomenon caused by uneven light. At the same time, the low intensity of green light will not cause strong photoinhibition, allowing the seedlings to gradually adapt to the light environment.

[0080] Blue light seedling growth stage (days 6-12): Spectral R / B ratio = 0.6:1, total light intensity 200 μmol·m⁻²·s⁻¹, almost devoid of green and white light. Principle: High proportion of blue light activates cryptochromes CRY1 and CRY2, downregulating the expression of gibberellin synthesis-related genes, thereby inhibiting excessive elongation of the hypocotyl and first leaf and promoting chloroplast development. During this stage, ryegrass seedling height decreased by 28% compared to the conventional light formula (R / B = 1.2:1), but leaf area and dry weight increased by 35% and 42%, respectively.

[0081] Red-blue equilibrium period (after day 13): Spectral R / G / B = 5:1:2, total light intensity 300 μmol·m⁻²·s⁻¹. Principle: As the canopy closes, the proportion of red light is increased to enhance the photosynthetic rate, while a suitable amount of green light is retained to penetrate the canopy, thereby increasing the photon flux density of the lower leaves.

[0082] This embodiment links the triggering time of aerial root pruning with the switching of light stages. Studies have shown that root cell division and elongation are highly dependent on the transport of photosynthetic products in the aboveground parts, and the distribution of photosynthetic products is significantly affected by light quality—blue light promotes the distribution of photosynthetic products to the roots, while red light promotes the distribution to the stems. Based on this, this embodiment designs the following synergistic strategy: During the vigorous seedling stage under blue light (days 6-12), the proportion of photosynthetic products allocated to the roots is at its highest. At this time, pruning aerial roots at the root tip incision point has the most significant effect on inducing lateral roots. Therefore, in this embodiment, aerial root pruning is fixed to be performed on the 7th and 10th days of the vigorous seedling stage under blue light, and the pruning time is selected at 3 hours after the start of light (when the sucrose content in the leaves reaches its daily peak).

[0083] During the red-blue balance period (after day 13), no new aerial root pruning is performed to allow the existing lateral roots to develop and elongate fully.

[0084] Execution Process: The microprocessor 602 maintains a "growth calendar" internally, automatically recording the sowing time and current growth stage. At 9:00 AM on the 7th day of the blue light seedling stage (3 hours after the start of illumination), the microprocessor 602 first instructs the light quality adjustable driver 402 to switch the LED spectral matrix 401 to blue light enhancement mode (R / B=0.4:1, lasting 30 minutes) to further mobilize the transport of photosynthetic products to the roots; 30 minutes later, the aerial root pruning program is initiated (parameters refer to Example 1, 190℃, 0.4 seconds); after pruning, the spectrum returns to the normal blue light seedling stage formulation. This sequential synergistic strategy increases the sucrose concentration at the root tip incision by approximately 60% compared to random pruning, advances the lateral root primordia germination time by 12 hours, and increases lateral root density by 35%.

[0085] Ryegrass seedlings were raised using the cultivation box described in this embodiment. The control group used the same equipment but with the spectral phase switching turned off (fixed R / G / B=4:2:2) and no temporal synergy. Results: On day 12, the seedling height in the experimental group was 82 mm, while that in the control group was 111 mm (excessive growth); the SPAD value of chlorophyll content in the experimental group was 44.6, while that in the control group was 36.2; the total root length in the experimental group was 168 mm, while that in the control group was 109 mm; the root-to-shoot ratio in the experimental group was 0.79, while that in the control group was 0.51; 15 days after transplanting, the survival rate in the experimental group was 98%, while that in the control group was 79%. This indicates that the temporal synergy of phased light quality regulation and aerial root pruning significantly improved the quality of ryegrass seedlings and the survival rate after transplanting.

[0086] In summary, this invention solves the problems of rhizosphere hypoxia, uneven light and heat, and poor seedling quality in forage seedling cultivation, and significantly improves germination rate and transplant survival rate.

Claims

1. A cultivation box for forage seedling raising, characterized in that, The main body of the box (1), the autonomous temperature and humidity control system (3), the intelligent lighting system (4), the circulating irrigation system (5), and the control system (6); The main body of the box (1) is composed of an outer insulation layer (101), an inner box wall (102) and a heat insulation material (103) filled between the outer insulation layer and the inner box wall. A sealed door (104) is provided on the front side of the main body of the box (1). The main body of the box (1) is provided with a multi-layer bearing layer (201) arranged vertically. Each bearing layer (201) is equipped with a seedling tray (202) that can be pulled out. The pulling direction of the seedling tray (202) is set towards the sealing door (104). The bottom of the seedling tray (202) is evenly provided with ventilation and water seepage holes (203). The autonomous temperature and humidity control system (3) includes a temperature and humidity controller (304) and a heating element (301), a semiconductor cooling and heating module (302), a humidifying nozzle array (303), and a temperature and humidity sensor (305) electrically connected to the temperature and humidity controller (304); the heating element (301), the humidifying nozzle array (303), and the temperature and humidity sensor (305) are all disposed on the inner wall (102); the semiconductor cooling and heating module (302) and the temperature and humidity controller (304) are disposed outside the main body (1) of the box. The intelligent lighting system (4) includes multiple lighting components (40) installed on the inner top wall of the main body of the box (1) and below each layer of the support layer (201). Each lighting component includes an LED spectral matrix (401), a light quality adjustable driver (402) electrically connected to the LED spectral matrix (401), and a light sensor array (403) uniformly distributed inside the main body of the box (1). The light direction of the LED spectral matrix (401) is towards the seedling tray (202). The circulating irrigation system (5) includes a nutrient solution storage tank (501) located at the bottom of the main body (1), a drip irrigation pipeline (502) buried under the seedling tray (202), a circulating pump (503) connecting the nutrient solution storage tank (501) and the drip irrigation pipeline (502), and a dissolved oxygen sensor (504) and a nutrient solution concentration sensor (505) located in the nutrient solution storage tank (501). The control system (6) includes an intelligent control panel (601) disposed on the outer wall of the main body (1) of the box and a microprocessor (602) integrated in the intelligent control panel (601). The microprocessor (602) is electrically connected to the temperature and humidity controller (304), the light quality adjustable driver (402), the circulation pump (503) and each sensor respectively.

2. The forage seedling cultivation box according to claim 1, characterized in that, The inner surface of the inner wall (102) is provided with a plurality of mounting slots (307) spaced vertically. Each mounting slot (307) contains a heating element (301). The heating element (301) is a graphene heat exchange strip. Each heating element (301) is connected to the heat exchange surface of the semiconductor cooling and heating module (302) through a flexible heat exchange strip, thereby forming a temperature gradient field with decreasing temperature from top to bottom inside the main body (1).

3. The forage seedling cultivation box according to claim 1, characterized in that, The seedling tray (202) includes a tray bottom plate (204), tray side walls (205) surrounding the tray bottom plate, and a biomimetic capillary permeation layer (206) disposed above the tray bottom plate (204). The tray bottom plate (204) is made of porous ceramic plate or sintered glass sand plate. Multiple air-permeable and water-permeable holes (203) are provided on the tray bottom plate (204). The multiple air-permeable and water-permeable holes (203) are evenly arranged in a honeycomb pattern on the tray bottom plate (204). The biomimetic capillary permeation layer (206) is a porous elastomer formed by cross-linking plant fibers and sodium alginate. The thickness of the biomimetic capillary permeation layer (206) is 8-15 mm, the porosity is 65%-80%, and the compression rebound rate is not less than 90%.

4. The forage seedling cultivation box according to claim 1, characterized in that, The circulating irrigation system (5) also includes a Venturi jet microbubble aeration device (506), which includes a Venturi tube (510) connected in series between the outlet of the circulating pump (503) and the drip irrigation pipeline (502), an air inlet pipe (511) communicating with the throat of the Venturi tube (510), and an air filter (512) installed at the inlet end of the air inlet pipe (511); the Venturi tube (510) is composed of a converging section (513), a throat (514) and a diffuser section (515) connected in sequence, the inner diameter of the throat (514) is 1 / 5 to 1 / 3 of the inner diameter of the inlet of the converging section (513), and at least one air intake hole (516) is provided on the wall of the throat (514). The air intake hole (516) is connected to the outside atmosphere through the air inlet pipe (511). When the circulating pump (503) drives the nutrient solution to flow through the Venturi tube (510), the flow velocity at the throat (514) increases sharply and the pressure drops sharply to negative pressure. Outside air is drawn in through the air inlet pipe (511) and broken into microbubbles with a diameter of 20-80 μm under the strong shearing action of the high-speed liquid flow, forming a gas-liquid mixture that enters the drip irrigation pipeline (502). The dissolved oxygen sensor (504) monitors the dissolved oxygen concentration in the nutrient solution storage tank (501) in real time and feeds it back to the microprocessor (602). The microprocessor (602) adjusts the rotation speed of the circulating pump (503) according to the concentration value to control the air intake and bubble generation rate.

5. The forage seedling cultivation box according to claim 4, characterized in that, The bottom of the seedling tray (202) is provided with a mechanical lifting aerial root trimming device (8). The mechanical lifting aerial root trimming device (8) includes a guide (804) fixedly installed below the seedling tray (202), a lifting plate (805) that can be slidably installed on the guide (804), an electric heating wire ring (806) fixed on the lifting plate (805) and arranged one-to-one with each of the air and water seepage holes (203), and a miniature electric push rod (803) connecting the lifting plate (805) and the tray bottom plate (204). The guide (804) includes 4 guide shafts and 4 fixing blocks; the 4 guide shafts are arranged in a rectangular shape, the top of the guide shafts are fixedly connected to the bearing layer (201), and the bottom of the guide shafts are fixedly connected to the inner box wall (102) through one of the fixing blocks; the heating wire ring (806) is electrically connected to a pulse heating controller through a flexible wire, and the micro electric push rod (803) and the pulse heating controller are respectively electrically connected to the microprocessor (602); the lighting component (40) is located below the lifting plate (805).

6. The forage seedling cultivation box according to claim 1 or 4, characterized in that, The irrigation pipe (502) is arranged in a wavy or serpentine pattern below the biomimetic capillary permeation layer (206) along the length of the seedling tray (202). Multiple micropores (509) are evenly distributed on the pipe wall of the irrigation pipe (502). The diameter of each micropore (509) increases in a stepped manner from the end closer to the circulating pump (503) to the end farther from the circulating pump (503), and its diameter distribution satisfies the following: d ( i )= d 0 ×(1 +k×i / L )， in d ( i ) is the first i The orifice diameter of the drip irrigation pipeline is given by L, the total length of the drip irrigation pipeline is given by k, the correction coefficient is given by d0, and the orifice diameter at the starting end is given by d0, so as to achieve the gradual infiltration of irrigation water.

7. The forage seedling cultivation box according to claim 1, characterized in that, Each lighting component (40) is fixedly connected to the inner box wall (102) via a transparent mounting block; the LED spectral matrix (401) and the light quality adjustable driver (402) are both disposed on the transparent mounting block; The LED spectral matrix (401) is composed of red, blue, green and white LED beads driven by multiple channels independently; the light quality adjustable driver (402) has a built-in spectral database, which stores the standard spectral curves required for pasture seedlings at three different stages: germination, seedling and growth; the light sensor array (403) collects the illuminance and spectral distribution data of each position inside the box in real time; the microprocessor (602) receives the data and compares it with the standard spectral curve, and then dynamically adjusts the output spectrum of the LED spectral matrix (401) through the light quality adjustable driver (402).

8. The forage seedling cultivation box according to claim 1, characterized in that, The sealed door (104) is a double-layer hollow tempered glass door, with inert gas filling the space between the two layers of glass. Magnetic sealing strips (106) are embedded around the door frame of the sealed door (104). A detachable sampling operation window (107) is embedded in the middle of the sealed door (104). A set of adjustable air intake fresh air inlets (108) is also provided on the back of the main body (1). An air filter (109) and an electric damper (110) are installed at the fresh air inlet (108). The electric damper (110) is electrically connected to the microprocessor (602).

9. The forage seedling cultivation box according to claim 1, characterized in that, The control system (6) also includes a remote communication module (603) and an audible and visual alarm that are electrically connected to the microprocessor (602).

10. The forage seedling cultivation box according to claim 3, characterized in that, Each of the bearing layers (201) includes two horizontally spaced fixing strips, the length direction of which is directed toward the sealing door (104); the outer sides of the two fixing strips are fixedly connected to the inner walls (102) on both sides of the main body (1), and each of the two fixing strips has a sliding groove (207); the side wall (205) of the disc has two sliders (208) that slide in cooperation with the sliding groove.

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