Desert soil temperature and humidity regulation and control system and method for rhizome plant planting

Abstract

The invention discloses a desert soil temperature and humidity regulation and control system and method for rhizome plant planting, and belongs to the technical field of soil improvement and desertification control. The composite structure with temperature regulation and control, water retention, wind prevention and sand fixation and long-term stability is needed, so that the efficiency of ecological management of the sand land is improved. The structure comprises a weather-proof surface layer, a phase-change sandy soil layer and a water-permeable supporting layer which are sequentially arranged from top to bottom; the weather-proof surface layer is a composite high-reflection phase-change coconut shred blanket and / or a radiation film, and preparation raw materials of the high-reflection phase-change coating at least comprise a coating matrix and a reflection filler; the phase-change sandy soil layer takes sandy soil as a matrix and contains phase-change microcapsules, the phase-change microcapsules comprise heat-exchangeable shell layers, and phase-change filler is arranged in the heat-exchangeable shell layers. The method does not need external energy consumption, can provide a long-term stable growth environment for rhizome plants in an arid desert environment, and has wide application prospects in desertification control, ecological restoration and arid agriculture.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement and desertification control technology, specifically relating to a desert soil temperature and humidity control system and method for planting rhizomatous plants. Background Technology

[0002] In desert and sandy environments, loose soil particles and drastic temperature fluctuations lead to high water evaporation, making it difficult for vegetation to survive. Traditional mulch materials, chemical amendments, or water-retaining agents suffer from poor durability, environmental pollution, or high costs. Phase change materials (PCMs) can absorb or release latent heat during phase change, thereby stabilizing soil temperature and reducing water evaporation. However, directly applying PCMs to sandy soils still presents challenges such as material leaching and insufficient environmental durability.

[0003] The cultivation of fruits and vegetables in deserts remains a hot research topic. Rhizomatous plants complete photosynthesis through their leaves, transporting the produced organic matter underground for root and tuber enlargement and storage. However, exposure to sunlight can lead to fibrosis and toxins in the tubers. While rhizomatous plants thrive in arid environments due to their underground roots not relying on sunlight, they still require stable hydrothermal conditions for development and yield. Existing desertification control and agricultural improvement measures are mostly single-function, failing to simultaneously meet the needs of temperature and humidity regulation and plant growth. Therefore, a composite structure is needed that combines temperature regulation, water conservation, windbreak and sand fixation, and long-term stability to improve the efficiency of desert ecological management. Summary of the Invention

[0004] To address the need for a composite structure in existing technologies that combines temperature regulation, water retention, windbreak and sand fixation, and long-term stability to improve the efficiency of desert ecological management, this invention provides a desert soil temperature and humidity control system and method for planting rhizomatous plants. The aim is to provide a desert soil temperature and humidity control system that utilizes microcapsule phase change materials and a high-reflectivity coating to form a dual heat and humidity control mechanism. Combined with a layered structure to optimize root growth conditions, it provides a stable hydrothermal environment for the growth of rhizomatous plants in arid environments, thereby improving vegetation survival rate and agricultural yield.

[0005] The technical solution adopted in this invention is as follows:

[0006] A desert soil temperature and humidity control system for planting rhizomatous plants includes a weather-resistant surface layer, a phase change sand layer, and a permeable support layer arranged from top to bottom.

[0007] The weather-resistant surface layer is a composite high-reflection phase change coconut fiber blanket and / or a radiation film. The composite high-reflection phase change coconut fiber blanket includes a coconut fiber blanket and a high-reflection phase change coating disposed on the coconut fiber blanket. The raw materials for preparing the high-reflection phase change coating include at least a coating matrix and a reflective filler.

[0008] The phase change sand layer uses sand as a matrix and contains several phase change microcapsules. Each phase change microcapsule includes a heat-exchangeable shell layer and a phase change filler is disposed within the heat-exchangeable shell layer.

[0009] With this technical solution, the present invention uses a permeable support layer as the bottom layer, which combines structural stability, drainage capacity and root penetration. A phase change sand layer is set on the permeable support layer, which provides a planting environment for plants. The weather-resistant surface layer on the phase change sand layer is used to reduce water evaporation. The reflective filler inside the phase change sand layer can reflect solar radiation to reduce heat exchange between the phase change sand layer and the outside world. Phase change microcapsules are set in the phase change sand layer. The phase change filler in the phase change microcapsules absorbs or releases latent heat through the phase change process, which stabilizes the diurnal temperature difference of the soil and slows down water evaporation.

[0010] As a preferred option, phase change microcapsules are also incorporated into the composite high-reflectivity phase change coconut fiber blanket.

[0011] Preferably, the phase change microcapsules have a particle size of 10-50 μm, and the doping amount of the phase change microcapsules is 4-8 wt% of the total weight of the sand and the phase change microcapsules.

[0012] After adopting this technical solution, the doping amount of phase change microcapsules is 5-8 wt% of the sandy soil mass to maintain soil permeability and plantability.

[0013] Preferably, the phase transition temperature of the phase change microcapsules is 28-35℃.

[0014] Preferably, the heat exchangeable shell is a composite shell of sodium alginate and chitosan or a PMMA shell, the phase change filler is one or two of lauric acid, palmitic acid or stearic acid, the filling amount of the phase change filler is 70%-80% of the total volume of the heat exchangeable shell, and the thickness of the heat exchangeable shell is 2.8–3.5 μm.

[0015] After adopting this technical solution, the phase change filler is one or two of lauric acid, palmitic acid or stearic acid because these phase change materials have good thermal cycling performance. When two phase change materials are used in combination, the required phase change temperature can be adjusted by adjusting the mixing ratio. The heat exchange shell is a composite shell of sodium alginate and chitosan, which has good mechanical strength and environmental adaptability. It can keep the sand particles completely covered and is not easy to break or leak.

[0016] As a preferred option, the amount of high-reflectivity phase change coating used is 3-4.5 kg per square meter of coconut fiber blanket.

[0017] Preferably, the reflective filler is one or more of silicon dioxide, titanium dioxide, and boron nitride, and the particle size of the reflective filler is 20-30 nm.

[0018] Preferably, the coconut fiber blanket has a thickness of 5-10 mm and is provided with several planting holes, the diameter of which is 5-15 mm and the depth is 10-20 mm, and the total cross-sectional area of ​​all the planting holes accounts for 5-20% of the total cross-sectional area of ​​the coconut fiber blanket.

[0019] As a preferred option, the thickness of the phase change sand layer is 10-25cm, and the thickness of the permeable support layer is 200-300mm.

[0020] Preferably, the permeable support layer comprises, from top to bottom, a first geotextile layer, a first gravel layer, a second gravel layer, and a second geotextile layer. The first gravel layer has a thickness of 100-150 mm and the gravel particle size in the first gravel layer is 5-10 mm. The second gravel layer has a thickness of 100-150 mm and the gravel particle size in the second gravel layer is 15-30 mm. The thickness of the first geotextile layer and the second geotextile layer is 0.5-2.0 mm, and the areal density is 300-400 g / m³. 2 The apparent opening size is 0.10-0.30 mm.

[0021] After adopting this technical solution, the thickness of the first gravel layer is 100-150 mm, and the gravel particle size in the first gravel layer is 5-10 mm. This layer has moderate porosity and can retain some water through capillary action, slowing down water infiltration and playing a role in "slow-release water source". The thickness of the second gravel layer is 100-150 mm, and the gravel particle size in the second gravel layer is 15-30 mm. This layer can quickly drain excess water during heavy rainfall or excessive irrigation, preventing the upper layer from becoming too wet and causing oxygen deficiency in plant roots. At the same time, the coarse-particle skeleton structure can significantly improve the overall compressive and shear strength, forming a stable load-bearing foundation. The thickness of the first geotextile layer and the second geotextile layer is 0.5-2.0 mm, and the areal density is 300-400 g / m³. 2 The apparent opening size is 0.10-0.30mm to ensure the retention of fine particles and long-term filtration and reinforcement functions.

[0022] Preferably, the phase change sand layer is also mixed with organic fertilizer, and the mass of the added organic fertilizer is 3-5 wt% of the total weight of the sand and organic fertilizer.

[0023] After adopting this technical solution, organic fertilizer can be biomass waste residue. For example, straw, weeds, fallen leaves, etc. can be crushed into residue and then mixed with animal manure and potato starch waste residue to obtain organic fertilizer.

[0024] A method for controlling temperature and humidity in desert soil for planting rhizomatous plants includes the following steps:

[0025] S1: Install the desert soil temperature and humidity control system for planting rhizomes in the desert;

[0026] S2: Root plants are planted on the weather-resistant surface. During the plant growth process, the high-reflectivity phase change coating reflects solar radiation and absorbs or releases latent heat through the phase change process of the phase change filler in the phase change microcapsules in the phase change sand layer, thus easing the diurnal temperature difference of the soil and slowing down water evaporation.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] This invention achieves a passive temperature regulation mechanism based on the natural circulation of solar radiation and surface heat flow by introducing phase change microcapsules with a phase change temperature of 28-35℃ into a phase change sand layer and setting a high-reflectivity phase change coating and coconut fiber blanket composite layer on top. During the high-temperature period of the day, the high-reflectivity phase change coating can significantly reduce the surface solar radiation absorption rate and reduce the conduction of incident heat to the lower layers; at the same time, the phase change microcapsules in the phase change sand layer absorb latent heat and undergo a solid-liquid phase change, converting part of the heat into an energy storage form, effectively weakening the rate of temperature rise of the sand. When the temperature drops at night, the microcapsules release the stored latent heat, achieving heat reversal compensation, keeping the sand temperature within a stable range suitable for root growth, thus constructing a diurnal self-balancing heat flow circulation system.

[0029] This invention utilizes a heat flow orientation and latent heat coupling mechanism between a high-reflectivity coating and a phase-change sand layer to achieve passive temperature control by storing heat during the day and releasing it at night. This reduces temperature fluctuations in the modified sand layer by 30%–50%, stabilizing the temperature difference within the range of 3–6°C. Simultaneously, the system works in conjunction with the capillary moisture conduction and water retention properties of coconut fiber blankets to create a synergistic thermo-humidity regulation effect. This system requires no external energy consumption and can provide a long-term, stable growth environment for rhizomatous plants in arid desert environments, demonstrating broad application prospects in desertification control, ecological restoration, and arid agriculture. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the desert soil temperature and humidity control system for planting rhizomatous plants in this invention;

[0031] Among them, 1-weather-resistant surface layer, 2-phase change sand layer, 3-permeable support layer, 301-first gravel layer, 302-second gravel layer, 303-first geotextile layer, and 304-second geotextile layer. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] Example 1

[0035] like Figure 1 As shown, a desert soil temperature and humidity control system for planting rhizomatous plants includes a weather-resistant surface layer 1, a phase change sand layer 2, and a permeable support layer 3 arranged from top to bottom.

[0036] The weather-resistant surface layer 1 includes a composite high-reflection phase-change coconut fiber blanket, which comprises a coconut fiber blanket and a high-reflection phase-change coating disposed on the coconut fiber blanket. The composite high-reflection phase-change coconut fiber blanket has a thickness of 10 mm and several planting holes are provided on the coconut fiber blanket. The diameter of the planting holes is 5-15 mm (10 mm in this embodiment), and the depth is 10-20 mm (15 mm in this embodiment, i.e., the planting hole extends from the coconut fiber blanket to the underlying phase-change sand layer 2). The total cross-sectional area of ​​all the planting holes accounts for 5-20% of the total cross-sectional area of ​​the coconut fiber blanket. 0% (15% in this embodiment), the raw materials for preparing the high-reflectivity phase change coating include a coating matrix and a reflective filler; the preparation method of the weather-resistant surface layer 1 in this embodiment is as follows: the coating matrix (in this embodiment, the coating matrix is ​​composed of PDMS (polydimethylsiloxane) and a curing agent) and the reflective filler (in this embodiment, boron nitride with a particle size of 20-30nm) are mixed, and the mass ratio of PDMS (polydimethylsiloxane), curing agent, and BN (boron nitride) is 1:0.1:0.6. After mixing, the mixture is evenly sprayed onto the surface of a 10mm thick coconut fiber blanket. Then, it is heated in an oven at 40℃ for 24 hours to form a film for use; the amount of high-reflectivity phase change coating used in this embodiment is 3kg per square meter of coconut fiber blanket;

[0037] The phase change sand layer 2 uses sand as a matrix, and the sand contains several phase change microcapsules. Each phase change microcapsule includes a heat-exchangeable shell layer, within which a phase change filler is disposed. In this embodiment, the sand particle size is 0.1-0.5 mm, and the porosity is 40%-50%. In this embodiment, the heat-exchangeable shell layer of the phase change microcapsules is made of PMMA, the phase change filler is tetradecane, the phase change temperature is 28℃, the enthalpy is 120 J / g, the tetradecane filling amount is 80% of the total volume of the heat-exchangeable shell layer, and the thickness of the heat-exchangeable shell layer is 3 μm. The phase change filler filling amount is 70%-80% of the total volume of the heat-exchangeable shell layer, and the thickness of the heat-exchangeable shell layer is 2.8–3.5 μm. In other embodiments, where the phase change microcapsules are non-toxic and do not affect the effectiveness of plant cultivation, phase change microcapsules within the same temperature range can be used for equivalent replacement. The preparation method of phase change sand layer 2 is as follows: sand, phase change microcapsules with a phase change temperature of 28℃, sodium hydroxymethyl cellulose (thickening agent to increase soil viscosity), and organic fertilizer (biomass waste residue) are mixed in a ratio of 1:0.05:0.01:0.05 and stirred evenly to obtain phase change sand. Then, phase change sand and water are added to the phase change sand in a mass ratio of 1:0.5 and sprinkled evenly to obtain phase change sand layer 2.

[0038] The preparation method of the desert soil temperature and humidity control system for rhizomatous plant cultivation is as follows: First, a second geotextile layer 303 is laid on the desert. Then, a second gravel layer 302 with a diameter of 15–30 mm is laid on the second geotextile layer 303. Subsequently, a first gravel layer 301 with a particle size of 5–10 mm is laid on the second gravel layer 302. Finally, a first geotextile layer 304 is laid on the first gravel layer 301. In this embodiment, the thickness of the first geotextile layer 304 and the second geotextile layer 303 is 1 mm, and the areal density is 300-400 g / m³. 2 The apparent opening size is 0.10-0.30 mm. Then, a phase change sand layer 2 with a thickness of 10 cm is set on the first geotextile layer 304. Finally, a weather-resistant surface layer 1 with a thickness of 10 mm is laid on the surface of the phase change sand layer 2, and plants are planted in the planting hole.

[0039] This invention achieves a passive temperature regulation mechanism based on the natural circulation of solar radiation and surface heat flow by introducing phase change microcapsules with specific phase change temperatures into a phase change sand layer and placing a composite high-reflectivity phase change coconut fiber blanket on top. During the high-temperature period of the day, the high-reflectivity phase change coating can significantly reduce the surface solar radiation absorption rate and reduce the conduction of incident heat to the lower layers. At the same time, the phase change microcapsules in the phase change sand layer and the high-reflectivity phase change coating absorb latent heat and undergo a solid-liquid phase change, converting some of the heat into a stored form, effectively weakening the rate of temperature rise in the sand. When the temperature drops at night, the microcapsules release the stored latent heat, achieving heat reversal compensation, maintaining the sand temperature within a stable range suitable for root growth, thus constructing a diurnal self-balancing heat flow circulation system.

[0040] Example 2

[0041] This embodiment is basically the same as Embodiment 1, except that: the phase change microcapsules are replaced with a heat exchange shell made of PMMA material, the phase change filler is paraffin wax, the phase change temperature is 32℃, the enthalpy value is 101 J / g, the amount of paraffin wax is 80% of the total volume of the heat exchange shell, the thickness of the heat exchange shell is 3μm, and the preparation method of the phase change sand layer 2 is as follows: sand, phase change microcapsules with a phase change temperature of 32℃, sodium hydroxymethyl cellulose, and organic fertilizer (biomass waste residue) are mixed in a ratio of 1:0.05:0.01:0.05, stirred evenly, and then 100g of water is added to obtain the phase change sand layer 2.

[0042] Example 3

[0043] This embodiment is basically the same as Embodiment 1, except that the composite high-reflectance phase change coconut fiber blanket is replaced with a radiation film. The radiation film is prepared by ball milling BN and SiO2 particles at a mass ratio of 8:1 to obtain homogeneous composite particles. PDMS (Part A, Part B), ethyl acetate, and composite particles are mixed at a mass ratio of 10:1:4:3 and magnetically stirred at room temperature for 2 hours to form a homogeneous system. The mixed solution is then poured into a pre-made mold and allowed to stand to level naturally. It is pre-cured at a low temperature of 35°C for 8 hours, and then cured at a high temperature of 70°C for 8 hours. After curing, the radiation film is obtained by removing it from the mold.

[0044] Comparative Example 1

[0045] This comparative example is basically the same as Example 1, except that the weather-resistant surface layer 1 is not provided.

[0046] Comparative Example 2

[0047] This comparative example is basically the same as Example 3, except that the phase change sand layer 2 is replaced with pure sand.

[0048] Examples 1-3 and Comparative Examples 1-2 were conducted in separate acrylic boxes to prevent interference. The blank control group (CK) consisted of pure sand of the same mass. Xenon lamps were used for the experiments, and the power of the xenon lamps was adjusted to simulate changes in solar radiation. The irradiance settings are shown in Table 1.

[0049] Table 1

[0050] Simulation time Experiment time (min) Target irradiance (W / m²) illustrate 06:00 (Sunrise) 0 0–50 Initial low light (morning glow) 08:00 20 400 rapid rise in the morning 10:00 40 700 High value in the morning 12:00 (noon) 60 1050 Peak value (short-term peak) 14:00 80 800 Gradual decay 16:00 100 400 Rapid descent in the evening 18:00 (Sunset) 120 0–50 The End (Dusk)

[0051] After the experiment, the mixture was cooled to room temperature for 120 minutes. Thermocouples were placed on the surface of phase change sand layer 2 and 5 cm away from the surface of phase change sand layer 2 to measure the temperature change. The room temperature was 25℃. The temperature change and water evaporation rate are shown in Table 2. (It should be noted that the evaluation criteria for strong, medium, weak and none of the nighttime condensation and backflow effect are: whether there is obvious water mist on the surface of the acrylic box and the degree of condensation and backflow after heating is stopped.)

[0052] Table 2

[0053]

[0054] As can be seen from Table 2, compared with the blank control group CK, both the examples and the comparative examples can reduce the temperature difference in the sand layer. However, in comparative examples 1 and 2, when using radiation film and phase change sand alone, the temperature difference in the sand layer is only controlled within the range of 7~8℃. In example 1, the use of phase change microcapsules and composite coconut fiber blankets can not only reduce the maximum temperature of the sand layer during the day, but also reduce the rate of temperature decrease after the sun disappears, forming a relatively gentle constant temperature platform. In the most preferred case, the present invention can maintain the temperature difference inside the sand within the range of 3±0.5℃ and effectively improve the water retention rate of the sand.

[0055] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A desert soil temperature and humidity control system for planting rhizomatous plants, characterized in that: It includes a weather-resistant surface layer (1), a phase change sand layer (2), and a permeable support layer (3) arranged from top to bottom. The weather-resistant surface layer (1) is a composite high-reflection phase change coconut fiber blanket and / or radiation film. The composite high-reflection phase change coconut fiber blanket includes a coconut fiber blanket and a high-reflection phase change coating disposed on the coconut fiber blanket. The raw materials for preparing the high-reflection phase change coating include at least a coating matrix and a reflective filler. The phase change sand layer (2) uses sand as the matrix and contains several phase change microcapsules. The phase change microcapsules include a heat exchange shell layer and a phase change filler is provided inside the heat exchange shell layer.

2. The desert soil temperature and humidity control system for rhizome plant cultivation according to claim 1, characterized in that: The phase change microcapsules have a particle size of 10-50 μm, and the doping amount of the phase change microcapsules is 4-8 wt% of the total weight of the sand and the phase change microcapsules.

3. The desert soil temperature and humidity control system for rhizome plant cultivation according to claim 1, characterized in that: The phase transition temperature of the phase change microcapsules is 28-35℃.

4. The desert soil temperature and humidity control system for rhizome plant cultivation according to claim 1, characterized in that: The amount of high-reflectivity phase change coating used is 3-4.5 kg per square meter of coconut fiber blanket.

5. The desert soil temperature and humidity control system for rhizome plant cultivation according to any one of claims 1-4, characterized in that: The reflective filler is one or more of silicon dioxide, titanium dioxide, and boron nitride, and the particle size of the reflective filler is 20-30 nm.

6. The desert soil temperature and humidity control system for rhizome plant cultivation according to any one of claims 1-4, characterized in that: The thickness of the coconut fiber blanket is 5-10mm, and several planting holes are provided on the coconut fiber blanket. The diameter of the planting holes is 5-15mm and the depth is 10-20mm. The total cross-sectional area of ​​all the planting holes accounts for 5-20% of the total cross-sectional area of ​​the coconut fiber blanket.

7. The desert soil temperature and humidity control system for rhizome plant cultivation according to any one of claims 1-4, characterized in that: The thickness of the phase change sand layer (2) is 10-25cm, and the thickness of the permeable support layer (3) is 200-300mm.

8. The desert soil temperature and humidity control system for rhizome plant cultivation according to claim 7, characterized in that: The permeable support layer (3) is composed of a first geotextile layer (304), a first gravel layer (301), a second gravel layer, and a second geotextile layer (303) arranged sequentially from top to bottom. The thickness of the first gravel layer (301) is 100-150 mm, and the gravel particle size in the first gravel layer (301) is 5-10 mm. The thickness of the second gravel layer (302) is 100-150 mm, and the gravel particle size in the second gravel layer (302) is 15-30 mm. The thickness of the first geotextile layer (304) and the second geotextile layer (303) is 0.5-2.0 mm, and the surface density is 300-400 g / m³. 2 The apparent opening size is 0.10-0.30 mm.

9. The desert soil temperature and humidity control system for rhizome plant cultivation according to any one of claims 1-4, characterized in that: The phase change sand layer (2) is also mixed with organic fertilizer, and the mass of the added organic fertilizer is 3-5 wt% of the total weight of the sand and organic fertilizer.

10. A method for controlling temperature and humidity in desert soil for planting rhizomatous plants, characterized in that: Includes the following steps: S1: Install the desert soil temperature and humidity control system for planting rhizomatous plants as described in any one of claims 1-9 in the desert; S2: Planting rhizomatous plants on the weather-resistant surface layer (1) allows the high-reflectivity phase change coating to reflect solar radiation during plant growth. The phase change filler in the phase change microcapsules in the phase change sand layer (2) absorbs or releases latent heat, thus mitigating the diurnal temperature difference of the soil and slowing down water evaporation.

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