Tropical region free-rain type seedling raising device and seedling raising method

Abstract

The application belongs to the field of nursery stock raising, and relates to a tropical area free-leaching type nursery stock raising cultivation device and a nursery stock raising method. The cultivation device comprises a water pipeline, the two ends of which are provided with plugs, and a bearing disc for placing a nursery container is installed on the axial direction of the water pipeline. The nursery stock raising method is to lay the water pipeline on the ground of a nursery greenhouse, to add water into the water pipeline, to place a nursery cup with transplanted nursery stock to be cultivated in the bearing disc, and then to carry out cultivation management, which comprises fertilizer management and water management. According to the principle of plant transpiration and capillary water absorption of the nursery substrate, the water pipeline is continuously drawn by the bottom pores of the nursery container, so that self-provision of water is realized, water utilization is improved, the cultivation quality of the straight root system nursery stock is improved, and remarkable technical advantages are formed in water saving, quality improvement, environmental protection, environmental interference resistance and the like, and the application is suitable for the high-temperature and high-humidity nursery environment.

Description

Technical Field

[0001] This invention belongs to the field of seedling cultivation, and relates to a seedling cultivation device and a seedling cultivation method. Specifically, it relates to a tropical region-free seedling cultivation device and seedling cultivation method that utilizes plant transpiration pull and capillary water absorption of the seedling substrate to achieve self-watering. Background Technology

[0002] Seedling cultivation, as a crucial link in forestry production, is an important guarantee for achieving economic, ecological, and social benefits. Currently, intensive factory-style seedling cultivation has become the main trend in seedling production due to its space-saving, time-saving, and high-quality seedlings. Container seedling cultivation is one of the main methods of intensive factory-style seedling cultivation; however, the supporting irrigation technology still has significant shortcomings, becoming a key bottleneck restricting the industry's water-saving efficiency and green development.

[0003] Seedlings are categorized into taproot seedlings and fibrous root seedlings. Different root systems require different cultivation methods, and the choice of seedling containers also varies. Currently, for taproot seedlings, conventional top sprinkler irrigation is used for water supply. While this method has low initial investment and is convenient, it consumes a large amount of water. Furthermore, due to water trapping by the leaves and evaporation through air, most irrigation water is wasted without being utilized by the roots. Moreover, this method often results in slow water penetration, leading to water loss and low water utilization. Deep roots cannot obtain sufficient water, hindering the development of strong, deep taproots and affecting seedling growth. Additionally, the constantly moist surface of the seedling substrate in the container easily breeds weeds. Moreover, the continuous erosion and penetration of water from above can cause the seedling substrate to harden, affecting its permeability and nutrient absorption, ultimately hindering root development. While drip irrigation or micro-irrigation technologies theoretically possess water-saving potential, drip irrigation equipment is prone to clogging due to algae and impurities in high-temperature and high-humidity environments. This can easily lead to localized interruptions in water and fertilizer supply to seedlings, affecting the uniformity of seedling growth and the quality of the finished product. For example, the irrigation channels (typically only 0.5–1.2 mm) are extremely susceptible to clogging due to algae growth and impurity sedimentation. This not only significantly increases facility maintenance costs but may also cause localized water stress in seedlings, making it unsuitable for use in actual high-temperature and high-humidity production environments.

[0004] Tidal seedling cultivation is a relatively new irrigation method that has emerged in recent years. It employs a bottom-watering approach for both the plant and the container, significantly improving irrigation efficiency and preventing fertilizer runoff. However, tidal seedling cultivation involves numerous components, including a water supply system, cultivation troughs, a disinfection system, a return water system, and a storage tank, resulting in substantial investment costs. Furthermore, different seedlings require specific substrates tailored to tidal seedling cultivation methods to stabilize root systems, supply nutrients, and regulate water, nutrient, and oxygen levels; otherwise, seedling quality will be directly affected. Additionally, the containers used for taproot seedlings are typically tall, and the bottom (including the substrate) often remains waterlogged, making the seedlings prone to root rot. Summary of the Invention

[0005] The purpose of this invention is to provide a tropical seedling cultivation device that eliminates the need for irrigation, addressing the shortcomings of existing technologies. Based on the characteristics of high temperature, easy evaporation of water, and high humidity in tropical regions, this device utilizes the transpiration pull of plants and the capillary absorption of the seedling substrate to achieve autonomous water supply, solving the problem of water waste in traditional irrigation, improving water utilization, and enhancing the cultivation quality of taproot seedlings.

[0006] The technical solution adopted in this invention: A tropical water-free seedling cultivation device includes a water pipe for holding irrigation water. Both ends of the water pipe are detachably fitted with plugs to seal the pipe and prevent leakage. A straight-through support plate, connected to the interior, is installed at intervals along the axial direction of the water pipe. The inner diameter of the support plate matches the outer diameter of the seedling container to support the container. The device ensures that there are no gaps or minimal gaps between the inner wall of the support plate and the side wall of the seedling container. The bottom of the seedling container is suspended (with a certain distance between it and the water surface inside the water pipe). This design ensures that the water in the pipe evaporates into water vapor and enters the substrate from the bottom of the seedling container, condensing into water droplets (the water diffuses smoothly under the capillary action of the substrate and is utilized by the seedling roots). It also completely prevents the roots from being directly immersed in water, thus avoiding root rot. This design balances water utilization efficiency with root growth and safety.

[0007] As a preferred embodiment of the present invention, a placement frame is detachably installed on the water pipe for stable placement of the water pipe, ensuring that the support plate faces upward. Further, the placement frame is composed of a ring clamp and a support frame.

[0008] As a preferred embodiment of the present invention, a limiting ring is provided on the inner side of the bearing plate to limit the placement depth of the seedling container and ensure the distance between the seedling container and the highest liquid level in the water pipe.

[0009] As a preferred embodiment of the present invention, the water pipe is provided with an overflow pipe to maintain the highest liquid level in the water pipe and prevent the liquid level from being too high and touching the bottom of the seedling container when water is added.

[0010] As a preferred embodiment of the present invention, the device further includes a water level alarm device for monitoring the water level in the water pipe, ensuring that the distance between the water level and the bottom of the seedling container is within the management requirements. When the distance between the water level and the bottom of the seedling container exceeds a set value, the alarm device sounds an alarm, and staff replenish water in the water pipe. Further, the water level alarm device includes a water level sensor, a control processing unit, and an audible and visual alarm.

[0011] Another object of the present invention is to provide a seedling cultivation method using the above-mentioned tropical region water-free seedling cultivation device, the specific steps of which are as follows: S1. Level the ground inside the seedling greenhouse with shading, ventilation, and temperature control functions, and seal both ends of the water pipes with plugs; lay multiple water pipes parallel to each other on the ground according to the planned spacing, with the support plate facing upwards; S2. Fill the water pipe with water until the water level in the pipe reaches its maximum. Then check all the seals again to ensure that the pipe is completely sealed, with no leaks or openings. S3. Transplant the seedlings to be cultivated into seedling containers filled with seedling substrate, and then place the seedling containers in the support tray. Control the minimum height difference between the bottom of the seedling container and the liquid level in the water pipe to be 3cm. Seal the port of the support tray where no seedling container is placed to ensure that the pipe is sealed and to prevent water evaporation. S4. Cultivation Period Management Fertilizer management: According to the growth needs of seedlings, regularly sprinkle granular compound fertilizer on the seedling substrate, and then cover it slightly with the substrate, or apply water-soluble fertilizer from top to bottom. Water management: Monitor the water consumption rate and replenish water into the water pipes to maintain the liquid level in the pipes, keeping the distance between the bottom of the seedling container and the liquid surface stable at 3-5cm until the seedlings reach the standard for leaving the nursery.

[0012] As a preferred embodiment of the present invention, the seedling substrate has a large number of micropores (approximately 0.1–1 mm in diameter) forming a natural capillary network. Further, the seedling substrate is coconut coir, or a mixture of coconut coir and topsoil, or a mixture of coconut coir and peat moss, wherein the volume ratio of coconut coir to topsoil is 3–5:1, and the volume ratio of coconut coir to peat moss is 3–4:1.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Based on the characteristics of high temperature, easy evaporation, and high humidity in tropical regions, this invention utilizes the principles of plant transpiration and capillary water absorption in the seedling substrate. It relies on the continuous transpiration pull of the seedling leaves to create negative pressure inside the seedling container, continuously drawing water from the water pipes through the pores at the bottom of the container. This achieves self-watering, solving problems such as water waste in traditional irrigation, insufficient moisture for deep roots, and root rot caused by prolonged water accumulation at the bottom of the seedling container in tidal irrigation. It improves water utilization and the cultivation quality of taproot seedlings, exhibiting significant technical advantages in water conservation, quality improvement, environmental protection, and resistance to environmental interference. It is suitable for high-temperature and high-humidity seedling environments.

[0014] 2. This invention utilizes the pores at the bottom of the seedling container as a water vapor inlet. Water vapor enters the seedling substrate, condenses into water droplets, and diffuses under the capillary action of the seedling substrate. The water content of the seedling substrate at the bottom is higher than that at the top, which is conducive to the vertical downward growth of the taproot and improves the quality of the seedlings.

[0015] 3. This invention adopts a capillary water absorption mode at the bottom of the seedling container, in which water is transported upward from the bottom of the seedling container. There is no loss such as water drift in the air, leaf interception, or surface evaporation. The overall water consumption can be reduced by 60-75%, and the water resource utilization rate is greatly improved. There is no surface leaching phenomenon throughout the process, which solves the problem of water waste in traditional irrigation.

[0016] 4. This invention adopts a closed bottom water supply mode, which keeps the surface of the seedling substrate relatively dry for a long time, which is not conducive to the germination and growth of weed seeds, greatly reduces the growth of weeds during the seedling period, and reduces the amount of manual weeding and the amount of herbicides used. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the longitudinal section of the tropical region-free seedling cultivation device of the present invention.

[0018] Figure 2 This is a side view of the tropical region-free seedling cultivation device of the present invention.

[0019] Figure 3 This is a cross-sectional structural diagram of the loading disk of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the placement rack of the present invention.

[0021] Figure 5 This is a diagram illustrating the usage state of the present invention.

[0022] In the diagram, 1 is a water pipe; 2 is a plug; 3 is a support plate; 4 is a placement rack; 5 is an overflow pipe; 6 is a limiting ring; 7 is a ring clamp; 8 is a bracket; and 9 is a seedling container. Detailed Implementation

[0023] The invention will be further described below with reference to examples and accompanying drawings, but this is not intended to limit the invention.

[0024] The present invention provides a tropical seedling cultivation device that does not require irrigation, such as... Figure 1 , 2 As shown, the system includes a water pipe 1, the material of which is not limited; corrosion-resistant materials such as plastic, PVC, and metal can be used. Plugs 2 are detachably installed at both ends of the water pipe to seal it, forming a closed tubular structure to prevent leakage. Installation openings are evenly spaced at 2-8cm intervals (depending on the size of the seedlings) along the water pipe, arranged linearly along the axial direction. A straight-through support plate 3 is installed on the installation opening and sealed, ensuring the support plate 3 is directly connected to the interior of the water pipe 1. The inner diameter of the support plate matches the outer diameter of the seedling container to support it, ensuring there are no gaps or minimal gaps between the support plate and the seedling container to prevent or minimize water evaporation. A detachable mounting rack 4 is installed on the water pipe to stabilize it, ensuring the loading plate faces upwards. An upward-bending overflow pipe 5 is installed on the side of the water pipe. The overflow pipe is made of transparent material and has scale markings. Its outlet position is equal to or slightly higher than the highest point of the water pipe 1. This is used to maintain the highest liquid level in the water pipe and prevent the liquid level from being too high and touching the bottom of the seedling container when adding water. At the same time, the transparent material makes it easy to observe the liquid level in the overflow pipe 5, thereby knowing the liquid level in the water pipe 1, and finally knowing the distance (height difference) between the liquid level in the water pipe 1 and the bottom of the seedling container.

[0025] The loading disk designed in this invention, such as Figure 3 As shown, it has a straight-through structure. The upper port is used to place the seedling container, and a limiting ring 6 is set on the inner side to limit the placement depth of the seedling container, ensuring the distance between the seedling container and the highest liquid level in the water pipe. The lower port is used to connect to the installation port on the water pipe. The distance between the limiting ring 6 and the lower end (or the distance between the limiting ring 6 and the installation port of the water pipe) is a maximum of 3cm. When the water pipe 1 is closed, the overflow pipe 5 and the limiting ring 6 can be used to control the minimum distance between the liquid level in the water pipe 1 and the bottom of the seedling container (the height difference between the water outlet of the overflow pipe 5 and the limiting ring 6) to meet the requirements of seedling cultivation, that is, the minimum distance is 3cm.

[0026] The placement rack designed in this invention, such as Figure 4 As shown, it consists of a ring hoop 7 and a bracket 8. The ring hoop 7 is used to lock and fix the placement rack to the water pipe 1, and the bracket 8 is used to place it on the ground of a conventional seedling greenhouse so that the loading tray faces upward.

[0027] Because the seedling leaves continuously transpire, a negative pressure is created in the seedling substrate area (especially the bottom) inside the seedling container. Under this negative pressure, water vapor evaporated from the water pipes continuously enters the seedling substrate through the bottom of the container and condenses into water droplets. Through capillary action in the seedling substrate, the water diffuses and is ultimately utilized by the roots. The sealed water pipes reduce water evaporation. The designed suspension height (with the bottom of the seedling container suspended and a height difference between it and the water surface inside the pipes) ensures smooth transpiration and capillary action in the seedling substrate, allowing the seedling roots to receive sufficient water, while completely preventing the roots from being directly immersed in water, thus balancing water use efficiency with root growth and safety.

[0028] When using the tropical water-free seedling cultivation device of the present invention, the effect is as follows: Figure 5 As shown, irrigation water is injected into water pipe 1, and seedling containers 9 are placed in the support tray 3 for seedling cultivation. During the cultivation process, the water level in water pipe 1 should be monitored in real time to maintain the liquid level in the pipe, ensuring that the distance between the bottom of the seedling container 9 and the liquid level in the water pipe is 3-5 cm, thus ensuring a smooth water supply to the seedlings. Water level monitoring can be done by having staff periodically observe the liquid level in the overflow pipe 5 according to the water consumption rate, or by installing a water level alarm device on the water pipe to monitor the water level. When the water level in the pipe drops and the distance (height difference) between the liquid level and the bottom of the seedling container exceeds the design requirements, water needs to be added to the pipe. Nutrient (fertilizer) can be added periodically, depending on the seedling growth stage, by sprinkling granular compound fertilizer onto the seedling substrate and then slightly covering it with the substrate, or by applying water-soluble fertilizer from top to bottom.

[0029] The present invention also provides a method for cultivating seedlings using the above-mentioned tropical region-free seedling cultivation device, the specific steps of which are as follows: S1. Level the ground inside the seedling greenhouse, which has shading, ventilation, and temperature control functions, to provide a stable growth environment for seedling cultivation. Cover all water pipes and the seedling cultivation area. Seal both ends of the water pipes with plugs. Lay multiple water pipes parallel to each other on the ground according to the planned spacing. When laying the water pipes, keep them as horizontal as possible with the bearing plate facing upwards. Use bricks to build a walkway between adjacent water pipes to facilitate staff to inspect the growth of seedlings and repair the pipe equipment. S2. Fill the water pipe with water until the water level in the pipe reaches its maximum. Then check all the seals again to ensure that the pipe is completely sealed, with no leaks or openings. S3. Select matching seedling trays according to the size of the carrier tray; transplant the seedlings to be cultivated into the seedling trays filled with seedling substrate, and then place the seedling trays inside the carrier tray (ensuring that the outer wall of the seedling tray is in close contact with the inner wall of the carrier tray to reduce water evaporation), controlling the minimum height difference between the bottom of the seedling tray and the liquid level in the water pipe to be 3cm. Seal the port of the carrier tray where no seedling trays are placed to ensure that the pipe is sealed and prevent water evaporation; S4, Cultivation and Management Fertilizer management: According to the growth needs of seedlings, regularly sprinkle granular compound fertilizer on the seedling substrate, and then cover it slightly with the substrate, or apply water-soluble fertilizer from top to bottom. Water management: Replenish water into the water pipes according to the water consumption rate and the growth stage of the seedlings, maintain the liquid level in the water pipes, and always ensure that the distance between the bottom of the seedling container and the liquid surface is stable at 3-5cm until the seedlings reach the standard for leaving the nursery.

[0030] Rubber tree seedlings were cultivated at the Rubber Research Institute Cultivation and Protection Base of the Chinese Academy of Tropical Agricultural Sciences in Danzhou City, Hainan Province, in July 2025. Seedling containers were selected. Experimental seedlings included seedlings that had survived budding with similar growth, budded seedlings, and tissue culture seedlings that had been hardened off.

[0031] Experimental Groups: Experimental Group 1 (Group A): 50 seedlings grafted from seed and budded, using coconut coir as the seedling substrate. The tropical region-free seedling cultivation device and seedling cultivation method of this invention were used for cultivation.

[0032] Experimental Group 2 (Group B): 50 budded seedlings were grown using a mixture of coconut coir and topsoil as the seedling substrate, with a volume ratio of coconut coir to topsoil of 4:1. The tropical region-free seedling cultivation device and seedling cultivation method of this invention were used for cultivation.

[0033] Experimental Group 3 (Group C): 50 tissue culture seedlings were grown using a mixture of coconut coir and peat moss as the seedling substrate, with a volume ratio of coconut coir to peat moss of 4:1. The seedlings were cultivated using the tropical region-free, water-free seedling cultivation device and method of this invention.

[0034] Control group 1 (Group D): 50 seedlings grafted from seed and budded, using coconut coir as the seedling substrate. Conventional cultivation methods were used (seedling tubes were placed on the ground, with top irrigation).

[0035] Control Group 2 (Group E): 50 budded seedlings were grown using a mixture of coconut coir and topsoil as the seedling substrate, with a volume ratio of coconut coir to topsoil of 4:1. Conventional cultivation methods were used (seedling trays were placed on the ground and top irrigation was applied).

[0036] Control group 3 (Group F): 50 tissue culture seedlings were grown using a mixture of coconut coir and peat moss as the seedling substrate, with a volume ratio of coconut coir to peat moss of 4:1. Conventional cultivation methods were used (seedling tubes were placed on the ground and top-sprinkled).

[0037] The seedling cultivation period was 4–8 months. Groups A, B, D, and E were observed and statistically analyzed when the seedlings developed their first and second clumps of leaves (before transplanting). Groups C and F were observed and statistically analyzed before transplanting. Average values ​​were calculated. The results are shown in Table 1.

[0038] Table 1 Cultivation status of different seedlings

[0039] The above results show that, compared with conventional cultivation methods, the cultivation of seedlings, budded seedlings, and tissue culture seedlings using the cultivation device and seedling cultivation method provided by this invention does not show significant differences in plant height, stem diameter, canopy spacing, and number of leaves, and is suitable for the cultivation of taproot seedlings.

[0040] To investigate the survival rate of rubber seedlings after transplanting to the field, seedlings from each of the above experimental groups were selected for field transplanting. The number of transplanted seedlings and the number of surviving seedlings were observed and counted, and the survival rate was calculated. The results are shown in Table 2.

[0041] Table 2. Transplanting of seedlings after nursery.

[0042] The above results indicate that when rubber seedlings, budded seedlings, and tissue culture seedlings are cultivated using the cultivation device and method of this invention, the survival rate of transplanted seedlings after leaving the nursery is not significantly different from that of conventional cultivation methods.

[0043] 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 technical principles 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 tropical region-free seedling cultivation device, characterized in that, It includes water pipes, with plugs installed at both ends of the water pipes. Straight-through support plates that connect to the inside are installed at intervals along the axial direction of the water pipes, and the inner diameter of the support plates matches the outer diameter of the seedling container.

2. The tropical region-free seedling cultivation device according to claim 1, characterized in that: A shelf can be detachably installed on the water pipe.

3. The tropical region-free seedling cultivation device according to claim 2, characterized in that: The placement frame consists of a ring and a support frame.

4. The tropical region water-free seedling cultivation device according to claim 1, characterized in that: A limit ring is provided on the inner side of the bearing plate.

5. The tropical region-free seedling cultivation device according to claim 1, characterized in that: An overflow pipe is installed on the water pipe.

6. The tropical region-free seedling cultivation device according to claim 1, characterized in that: It also includes a water level alarm device.

7. The tropical region-free seedling cultivation device according to claim 6, characterized in that: The water level alarm device includes a water level sensor, a control processing unit, and an audible and visual alarm.

8. A method for cultivating seedlings using the tropical region-free seedling cultivation device according to claim 1, characterized in that, The specific steps are as follows: S1. Level the ground inside the seedling greenhouse with shading, ventilation, and temperature control functions, and seal both ends of the water pipes with plugs; lay multiple water pipes parallel to each other on the ground according to the planned spacing, with the support plate facing upwards; S2. Fill the water pipe with water until the water level in the pipe reaches its maximum. Then check all the seals again to ensure that the pipe is completely sealed, with no leaks or openings. S3. Transplant the seedlings to be cultivated into seedling containers filled with seedling substrate, and then place the seedling containers in the support tray. Control the minimum height difference between the bottom of the seedling container and the liquid level in the water pipe to be 3cm. Seal the port of the support tray where no seedling container is placed to ensure that the pipe is sealed and to prevent water evaporation. S4. Cultivation Period Management Fertilizer management: According to the growth needs of seedlings, regularly sprinkle granular compound fertilizer on the seedling substrate, and then cover it slightly with the substrate, or apply water-soluble fertilizer from top to bottom. Water management: Monitor the water consumption rate and replenish water into the water pipes to maintain the liquid level in the pipes, keeping the distance between the bottom of the seedling container and the liquid surface stable at 3-5cm until the seedlings reach the standard for leaving the nursery.

9. The seedling cultivation method according to claim 8, characterized in that: The seedling substrate has a large number of tiny pores inside; the seedling substrate is coconut coir, or a mixture of coconut coir and topsoil, or a mixture of coconut coir and peat, wherein the volume ratio of coconut coir to topsoil is 3-5:1, and the volume ratio of coconut coir to peat is 3-4:1.

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