Tropical orchid culture medium as well as preparation method and application thereof

Abstract

The invention relates to the technical field of plant cultivation substrates, and particularly discloses a tropical orchid cultivation substrate and a preparation method and application thereof. The tropical orchid culture medium is prepared from the following raw materials: 40 to 60 parts of modified pine bark, 25 to 35 parts of composite modified coco coir, 8 to 12 parts of porous basalt particles, 3 to 6 parts of vermiculite powder, 4 to 8 parts of charcoal, 2 to 5 parts of humic acid and 1 to 3 parts of amino acid chelated fertilizer, the modified pine bark is obtained by loading a template on decomposed pine bark and carrying out gradient roasting; the composite modified coco coir is obtained by soaking coco coir in a chitosan-aluminum ion composite solution for modification and then drying. According to the culture medium, the special requirements of tropical orchid aerial roots are comprehensively considered on the whole, and the balance of air permeability and water retention is achieved through the synergistic effect of multiple raw materials; powerful support is provided for large-scale and standardized cultivation of the tropical orchid.

Description

Technical Field

[0001] This application relates to the field of plant cultivation substrate technology, and more specifically, to a tropical orchid cultivation substrate, its preparation method, and its application. Background Technology

[0002] Tropical orchids, also known as exotic orchids, are a general term for orchid plants distributed in low-latitude tropical and subtropical regions. Common varieties include Cattleya, Phalaenopsis, Cymbidium, Dendrobium, and Oncidium. These orchids are characterized by their large, uniquely shaped, and vibrant flowers, as well as their long blooming period. They possess extremely high ornamental and economic value, and have become popular potted plants and cut flowers worldwide, with particularly strong demand in North America, Japan, and Europe. Unlike terrestrial orchids of temperate regions, tropical orchids are mostly epiphytic, with well-developed, fleshy aerial roots. In their native environment, they often grow epiphytically on tree trunks, branches, or rock surfaces, relying on air, rainwater, and humus in their environment for water and nutrients. In the current large-scale cultivation of tropical orchids, the main propagation method is tissue culture. The cultivation cycle of finished flowers is usually 2-4 years. Cultivation management requires strict control of temperature, light and water conditions. Watering should follow the principle of "watering thoroughly when the surface is dry". During the growing season, special fertilizers should be sprayed regularly to ensure nutrient supply.

[0003] The cultivation substrate, as the core carrier for tropical orchid growth, is not soil in the traditional sense. Its core functions are to provide stable support for aerial roots, a well-aerated environment, suitable water retention, and nutrient supply. It directly determines the quality of root development, plant growth, and flowering quality, making it a key element for successful tropical orchid cultivation. From an industry development perspective, substrate costs account for a significant proportion of the total cost of tropical orchid cultivation, directly impacting the overall production cost and market competitiveness of the industry. High-quality substrate can significantly improve cultivation survival rates and yields, promoting the large-scale and standardized development of the industry; conversely, inferior substrate can easily lead to cultivation failures, hindering the improvement of industry efficiency. In existing technologies, tropical orchid cultivation substrates are mainly divided into three categories: organic substrates, inorganic substrates, and composite substrates. Organic substrates include decomposed pine bark, sphagnum moss, coconut coir, sphagnum moss, and leaf mold, among which sphagnum moss is currently the most commonly used substrate material due to its strong water retention and loose texture. Inorganic substrates include pumice, volcanic rock, expanded clay, and perlite, which are mainly used to enhance the substrate's aeration and drainage. Composite substrates are balanced substrates formed by mixing organic and inorganic materials in different proportions, such as a combination of pine bark, pumice, and sphagnum moss, to balance the needs for aeration, water retention, and nutrient supply.

[0004] Although existing cultivation substrates are widely used in tropical orchid cultivation, they generally suffer from a core deficiency: a balance between aeration and water retention capacity, limited by the rationality of their formulation and the characteristics of their raw materials. This deficiency directly affects the normal physiological function of the aerial roots of tropical orchids, thus restricting plant growth and development. Specifically, on the one hand, while single organic substrates, such as sphagnum moss, have strong water retention, they are prone to compaction after long-term use, leading to a sharp decrease in aeration. Actual measurements show that after three months of use, the porosity of sphagnum moss substrate decreased from the initial 65%-70% to 25%-30%, far below the minimum porosity standard required for the growth of aerial roots in tropical orchids. The roots are in a long-term oxygen-deficient environment, which easily leads to root rot and a high rate of yellowing of the plant. At the same time, compacted sphagnum moss has poor drainage, and the substrate retains water for too long after watering, further exacerbating the root hypoxia problem. On the other hand, some composite substrates, in pursuit of improved aeration, excessively increase the proportion of inorganic substrate, resulting in severely insufficient water retention. The substrate moisture content struggles to maintain the optimal 50%-60% range for tropical orchid growth, failing to provide a stable water supply to the aerial roots. This leads to water stress in the plants, manifesting as wilting leaves and delayed new shoot emergence. Therefore, the core flaw in orchid cultivation substrates in related technologies is the inability to simultaneously achieve both aeration and water retention. This makes it difficult to adapt to the dynamic needs of tropical orchids at different growth stages, ultimately resulting in lower survival rates and inconsistent quality of finished flowers, thus hindering the standardization and large-scale development of the tropical orchid cultivation industry. Summary of the Invention

[0005] In order to simultaneously consider the air permeability and water retention properties of tropical orchid cultivation substrate, this application provides a tropical orchid cultivation substrate, its preparation method and application.

[0006] This application provides a tropical orchid cultivation substrate, its preparation method, and its application, employing the following technical solution:

[0007] A tropical orchid cultivation substrate, comprising the following raw materials in parts by weight:

[0008] 40-60 parts of modified pine bark;

[0009] 25-35 parts of composite modified coconut coir;

[0010] 8-12 parts of porous basalt particles;

[0011] 3-6 parts vermiculite powder;

[0012] 4-8 parts biochar;

[0013] 2-5 parts humic acid;

[0014] 1-3 parts of amino acid chelated fertilizer;

[0015] The modified pine bark is obtained by loading a template and gradient calcination of decomposed pine bark;

[0016] The composite modified coconut coir is obtained by soaking and modifying coconut coir in a chitosan-aluminum ion composite solution and then drying it.

[0017] By adopting the above-mentioned technical solution, the tropical orchid cultivation substrate provided in this application effectively solves the problem of balancing air permeability and water retention in existing technologies through a scientifically and rationally combined raw material. Modified pine bark, as one of the core components, undergoes special treatments such as loading templates and gradient calcination to construct a multi-level porous structure. The micron-sized macropores in this structure form the main air permeable channels that penetrate the substrate, providing sufficient oxygen for the aerial roots of tropical orchids to breathe, avoiding the problem of oxygen deficiency in aerial roots caused by excessively small pores in a single substrate, and ensuring the normal physiological functions of the root system. Simultaneously, the submicron-sized mesopores and nano-sized micropores act as water storage units, adsorbing and storing appropriate amounts of water. Through capillary action, water is uniformly conducted within the substrate, significantly increasing the total porosity while maintaining stable aeration porosity within a suitable range. This resolves the inherent contradiction of "high air permeability leading to poor water retention," providing a good air permeability and water retention environment for the growth of tropical orchids. After being modified by soaking in a chitosan-aluminum ion composite solution, the amino and hydroxyl groups of chitosan form a hydrogen bond network, enhancing water retention. Aluminum ions improve the structural stability of the coconut coir, preventing caking and maintaining good air permeability. This synergistically solves the problems of easy caking and poor air permeability in single organic substrates. The rational addition of porous basalt particles, vermiculite powder, biochar, humic acid, and amino acid chelated fertilizer optimizes the substrate performance from different aspects. Porous basalt particles enhance the substrate's air permeability and drainage; vermiculite powder helps retain water and provide nutrients; biochar improves the substrate structure and adsorbs harmful substances; humic acid regulates the substrate's pH and nutrient availability; and amino acid chelated fertilizer provides comprehensive nutrients for tropical orchids. Together, they create suitable conditions for the growth of tropical orchids, improving cultivation survival rate and the quality of finished flowers.

[0018] The cultivation substrate of this application comprehensively considers the special needs of tropical orchids' aerial roots, achieving a perfect balance between aeration and water retention through the synergistic effect of multiple raw materials. Compared with existing single organic substrates or composite substrates, the substrate of this application can better adapt to the dynamic needs of tropical orchids at different growth stages for aeration and water retention, avoiding problems such as root rot, plant yellowing, and water shortage stress caused by poor aeration or water retention. This provides strong support for the large-scale and standardized cultivation of tropical orchids and helps promote the development of the tropical orchid cultivation industry.

[0019] Furthermore, the cultivation substrate of this application emphasizes environmental protection and sustainability in its raw material selection. Modified pine bark and composite modified coconut coir, among other raw materials, are widely available and renewable, reducing reliance on non-renewable resources. Simultaneously, the addition of biochar helps improve the soil's ecological environment, aligning with the concept of green development in modern agriculture. This environmentally friendly cultivation substrate not only benefits the sustainable development of the tropical orchid industry but also reduces negative environmental impacts, possessing high ecological value and social benefits.

[0020] Preferably, the modified pine bark is prepared using the following method:

[0021] A1. Place the decomposed pine bark in a sodium hydroxide solution and soak it at a constant temperature of 60-70℃ for 2-3 hours. Remove it and rinse it with deionized water until neutral. Dry it at 65-75℃ until constant weight to obtain degreased pine bark.

[0022] A2. Soak defatted pine bark in a precursor solution, then add template agent, soak at room temperature for 12-16 hours, and sonicate 2-4 times during the period, 30 minutes each time. After soaking, take it out and dry it to obtain template-loaded pine bark.

[0023] A3. Place the template-loaded pine bark in a programmed heating furnace, heat it to 350-400℃, hold it for 2-3 hours, then heat it to 550-600℃ and hold it for 2-3 hours. After naturally cooling to room temperature, soak it in a 10%-15% hydrofluoric acid solution for 30-60 minutes to remove the template. Rinse it with deionized water until neutral, and dry it to obtain modified pine bark.

[0024] Preferably, in step A1, the mass concentration of the sodium hydroxide solution is 5%-10%, and the mass ratio of the decomposed pine bark to the sodium hydroxide solution is 1:8-12.

[0025] Preferably, in step A2, the precursor solution is a silica sol with a mass concentration of 8%-12%, and the mass ratio of the degreased pine bark to the silica sol is 1:10-15.

[0026] Preferably, in step A2, the template agent is a mixture of polyethylene glycol-400 and hexadecyltrimethylammonium bromide in a weight ratio of 3-5:1, and the amount of template agent added is 5%-8% of the mass of silica sol.

[0027] By employing the above-mentioned technical solution, gradient modification of pine bark was achieved through a series of precise steps. First, the decomposed pine bark was immersed in a sodium hydroxide solution at a constant temperature and then rinsed and dried. This step effectively removed impurities such as oils from the pine bark, creating favorable conditions for subsequent modification. Next, the defatted pine bark was immersed in a precursor solution with a template agent added, then immersed at room temperature and ultrasonically treated. This ensured that the template agent was uniformly loaded onto the pine bark, laying the foundation for the formation of a hierarchical porous structure. Finally, gradient calcination was performed in a programmed temperature furnace, and the template was removed with hydrofluoric acid solution at a specific temperature, resulting in modified pine bark with an ideal hierarchical porous structure. This preparation method is scientifically sound and allows for precise control of the modification process, ensuring that the modified pine bark possesses a stable hierarchical porous structure. This allows it to better fulfill its core role in air permeability and water conduction within the matrix, effectively solving the problem of balancing air permeability and water retention in existing technologies.

[0028] Preferably, the composite modified coconut coir is prepared by the following method:

[0029] Coconut coir is placed in a chitosan-aluminum ion composite solution and soaked at room temperature for 8-10 hours. After being taken out, it is dried in an oven at 55-65℃ until the moisture content is 10%-12%, thus obtaining composite modified coconut coir.

[0030] Preferably, the chitosan-aluminum ion composite solution is a mixed solution prepared by mixing a chitosan solution with a mass concentration of 0.8%-1.5% and an aluminum nitrate solution with a mass concentration of 0.8%-1.6% at a volume ratio of 1:1, and the mass ratio of coconut coir to chitosan-aluminum ion composite solution is 1:6-10.

[0031] By employing the above-mentioned technical solution, coconut coir is soaked in a chitosan-aluminum ion composite solution at room temperature and then dried to obtain composite modified coconut coir. The special ratio of the chitosan-aluminum ion composite solution allows the amino and hydroxyl groups of chitosan to fully form a hydrogen bond network, enhancing the water retention of the coconut coir. Simultaneously, aluminum ions improve the structural stability of the coconut coir, preventing caking during long-term use. This preparation method is simple and easy to implement, effectively improving the performance of coconut coir and allowing it to function better in the substrate. It works synergistically with modified pine bark and other components to solve the problem of balancing air permeability and water retention, providing a more suitable substrate environment for the growth of tropical orchids.

[0032] Preferably, the porous basalt particles have a particle size of 3-8 mm and a porosity of 45%-55%; the biochar is coconut shell biochar with a particle size of 0.5-2 mm.

[0033] By employing the aforementioned technical solutions, porous basalt particles possess specific particle size and porosity. These particles, with their defined dimensions, can form excellent aeration channels within the substrate, enhancing its air permeability and drainage, and preventing waterlogging that could lead to oxygen deficiency in the tropical orchid roots. The specified particle size of the coconut shell biochar also contributes to its uniform distribution within the substrate, improving its structure, increasing porosity and air permeability, while simultaneously adsorbing harmful substances, thus providing a healthier environment for tropical orchid growth. These specifications allow the porous basalt particles and biochar to better integrate with other components, jointly addressing the challenge of balancing substrate air permeability and water retention, thereby improving the overall performance of the substrate.

[0034] Secondly, this application provides a method for preparing a tropical orchid cultivation substrate, employing the following technical solution:

[0035] A method for preparing a tropical orchid cultivation substrate includes the following steps:

[0036] S1. Place the modified pine bark, composite modified coconut coir, porous basalt particles, vermiculite powder, biochar, humic acid and amino acid chelated fertilizer in a mixer and mix at a speed of 200-300 r / min for 15-20 min to obtain a mixed substrate.

[0037] S2. Place the mixed substrate in a UV sterilizer at 30-40 μW / cm². 2 Sterilize with irradiation intensity for 30-40 minutes, and the resulting tropical orchid cultivation substrate is obtained after sterilization.

[0038] Thirdly, this application provides an application of a tropical orchid cultivation substrate in tropical orchid cultivation, employing the following technical solution:

[0039] The application of a tropical orchid cultivation substrate in the cultivation of tropical orchids involves filling the cultivation container with the substrate, which is 15-25 cm thick. Tropical orchid seedlings are then planted in the substrate at a depth of 3-5 cm, ensuring that the roots are in full contact with the substrate. Conventional cultivation and care are then carried out.

[0040] By adopting the above technical solution, the application method of tropical orchid cultivation substrate is specified. The substrate is filled into cultivation containers, and the substrate thickness and planting depth of tropical orchid seedlings are controlled before routine cultivation and care. This application method clarifies the actual use of the cultivation substrate in cultivation. A reasonable substrate thickness provides sufficient growth space for the tropical orchid roots, while ensuring that the substrate's aeration and water retention meet the plant's growth needs. An appropriate planting depth helps the tropical orchid seedling roots to fully contact the substrate, quickly adapt to the new growth environment, and absorb water and nutrients from the substrate. Applying the cultivation substrate according to this method can fully utilize the advantages of the substrate, improve the cultivation effect of tropical orchids, solve problems such as poor plant growth and development caused by improper substrate application in existing technologies, and promote the healthy development of the tropical orchid cultivation industry.

[0041] In summary, this application has the following beneficial effects:

[0042] 1. This application uses modified pine bark as one of its core components and employs special treatments such as loading templates and gradient calcination to construct a multi-level porous structure. The micron-sized macropores form the main permeable channels that penetrate the matrix, providing ample oxygen for the aerial roots of tropical orchids and preventing oxygen deficiency. The submicron-sized mesopores and nano-sized micropores act as water storage units, adsorbing and storing appropriate amounts of water, and achieving uniform water conduction within the matrix through capillary action. This structure allows for a significant increase in the total porosity of the matrix while maintaining stable aeration porosity within a suitable range, effectively solving the problem of balancing air permeability and water retention in existing technologies, and providing a good air permeability and water retention environment for the growth of tropical orchids.

[0043] 2. This application preferably uses composite modified coconut coir. After being modified by soaking in a chitosan-aluminum ion composite solution, the amino and hydroxyl groups of chitosan form a hydrogen bond network, enhancing water retention. The aluminum ions improve the structural stability of the coconut coir, preventing caking and maintaining good air permeability. Synergistically, with modified pine bark and other components, it further solves the problems of easy caking and poor air permeability of single organic substrates, optimizing the substrate performance from different aspects. Together, they create suitable conditions for the growth of tropical orchids, improving cultivation survival rate and finished flower quality, and better adapting to the dynamic needs of tropical orchids at different growth stages for air permeability and water retention.

[0044] 3. The method described in this application, through a scientifically sound combination of raw materials and precise preparation processes, not only emphasizes the environmental friendliness and sustainability of raw materials, selecting widely available and renewable modified pine bark and composite modified coconut coir, reducing dependence on non-renewable resources, but also, through the addition of biochar, helps improve the soil ecological environment. Furthermore, it specifies detailed application methods, clarifying the actual use of the cultivation substrate in cultivation. Reasonable substrate thickness and appropriate planting depth help tropical orchid seedlings' roots to fully contact the substrate, quickly adapt to the new growth environment, and absorb water and nutrients from the substrate. This environmentally friendly cultivation substrate and scientific application method are conducive to the sustainable development of the tropical orchid industry, reduce negative environmental impacts, possess high ecological value and social benefits, and promote the healthy development of the tropical orchid cultivation industry. Detailed Implementation

[0045] The present application will be further described in detail below with reference to the embodiments.

[0046] Example of preparation of modified pine bark

[0047] Preparation Example 1

[0048] Modified pine bark was prepared using the following method:

[0049] A1. Place 10 kg of decomposed pine bark with an average particle size of 5 cm into 80 kg of 5% sodium hydroxide solution and soak at 60°C for 2 hours. Remove the bark, rinse it with deionized water until neutral, and dry it at 65°C to constant weight to obtain degreased pine bark.

[0050] A2. Immerse 10 kg of degreased pine bark in 100 kg of silica sol with a mass concentration of 8%, then add 5 kg of template agent, which is a mixture of polyethylene glycol-400 and hexadecyltrimethylammonium bromide in a weight ratio of 3:1. Soak at room temperature for 12 hours, during which time ultrasonic treatment is performed twice, 30 minutes each time. After soaking, remove and dry to obtain template-loaded pine bark.

[0051] A3. Place the template-loaded pine bark in a programmed heating furnace, heat it to 350℃, hold it for 2 hours, then heat it to 550℃ and hold it for 2 hours. After naturally cooling to room temperature, soak it in a 10% hydrofluoric acid solution for 30 minutes to remove the template, rinse it with deionized water until neutral, and dry it to obtain modified pine bark.

[0052] Preparation Example 2

[0053] Modified pine bark was prepared using the following method:

[0054] A1. Place 10 kg of decomposed pine bark with an average particle size of 5 cm into 100 kg of sodium hydroxide solution with a mass concentration of 8%, soak at a constant temperature of 65℃ for 2.5 h, remove and rinse with deionized water until neutral, and dry at 70℃ to constant weight to obtain degreased pine bark.

[0055] A2. Immerse 10 kg of degreased pine bark in 125 kg of silica sol with a mass concentration of 10%, and then add 8 kg of template agent. The template agent is a mixture of polyethylene glycol-400 and hexadecyltrimethylammonium bromide in a weight ratio of 4:1. Soak at room temperature for 14 hours, and ultrasonically treat 3 times during the period, each time for 30 minutes. After soaking, take it out and dry it to obtain template-loaded pine bark.

[0056] A3. Place the template-loaded pine bark in a programmed heating furnace, heat it to 375℃, hold it for 2.5 hours, then heat it to 575℃ and hold it for 2.5 hours. After naturally cooling to room temperature, soak it in a 12% hydrofluoric acid solution for 45 minutes to remove the template, rinse it with deionized water until neutral, and dry it to obtain modified pine bark.

[0057] Preparation Example 3

[0058] Modified pine bark was prepared using the following method:

[0059] A1. Place 10 kg of decomposed pine bark with an average particle size of 5 cm into 120 kg of sodium hydroxide solution with a mass concentration of 10% and soak at a constant temperature of 70°C for 3 hours. Remove the bark, rinse it with deionized water until neutral, and dry it at 75°C to constant weight to obtain degreased pine bark.

[0060] A2. Immerse 10 kg of degreased pine bark in 150 kg of silica sol with a mass concentration of 12%, and then add 12 kg of template agent. The template agent is a mixture of polyethylene glycol-400 and hexadecyltrimethylammonium bromide in a weight ratio of 5:1. Soak at room temperature for 16 hours, and ultrasonically treat 4 times during the period, each time for 30 minutes. After soaking, take it out and dry it to obtain template-loaded pine bark.

[0061] A3. Place the template-loaded pine bark in a programmed heating furnace, heat it to 400℃, hold it for 3 hours, then heat it to 600℃ and hold it for 3 hours. After naturally cooling to room temperature, soak it in a 15% hydrofluoric acid solution for 60 minutes to remove the template, rinse it with deionized water until neutral, and dry it to obtain modified pine bark.

[0062] Preparation example of composite modified coconut coir

[0063] Preparation Example 4

[0064] The composite modified coconut coir was prepared by the following method:

[0065] 10 kg of coconut coir with an average particle size of 3 cm was placed in 60 kg of chitosan-aluminum ion composite solution. The chitosan-aluminum ion composite solution was a mixed solution prepared by mixing 0.8% chitosan solution and 0.8% aluminum nitrate solution at a volume ratio of 1:1. The mixture was soaked at room temperature for 8 hours, and then dried in an oven at 55℃ until the moisture content was 12%, thus obtaining the composite modified coconut coir.

[0066] Preparation Example 5

[0067] The composite modified coconut coir was prepared by the following method:

[0068] 10 kg of coconut coir with an average particle size of 3 cm was placed in 80 kg of chitosan-aluminum ion composite solution. The chitosan-aluminum ion composite solution was a mixed solution prepared by mixing chitosan solution with a mass concentration of 1.2% and aluminum nitrate solution with a volume ratio of 1:1. The mixture was soaked at room temperature for 9 hours, and then dried in an oven at 60℃ until the moisture content was 11%, thus obtaining the composite modified coconut coir.

[0069] Preparation Example 6

[0070] The composite modified coconut coir was prepared by the following method:

[0071] 10 kg of coconut coir with an average particle size of 3 cm was placed in 100 kg of chitosan-aluminum ion composite solution. The chitosan-aluminum ion composite solution was a mixed solution prepared by mixing chitosan solution with a mass concentration of 1.5% and aluminum nitrate solution with a volume ratio of 1:1. The mixture was soaked at room temperature for 10 h, and then dried in an oven at 65 ℃ until the moisture content was 10%, thus obtaining the composite modified coconut coir.

[0072] Example

[0073] Example 1

[0074] A tropical orchid cultivation substrate, the raw material components and proportions of which are shown in Table 1, wherein the modified pine bark is the modified pine bark prepared in Preparation Example 1; the composite modified coconut coir is the composite modified coconut coir prepared in Preparation Example 4; the porous basalt particles have a particle size of 3 mm; the biochar is coconut shell biochar with a particle size of 0.5 mm; and the composite amino acid chelated fertilizer is a mixture of amino acid chelated iron, amino acid chelated calcium, and amino acid chelated magnesium in a weight ratio of 3:2:1.

[0075] The above-mentioned tropical orchid cultivation substrate was prepared using the following method:

[0076] S1. Modified pine bark, composite modified coconut coir, porous basalt particles, vermiculite powder, biochar, humic acid and amino acid chelated fertilizer are placed in a mixer and mixed at a speed of 200 r / min for 15 min to obtain a mixed substrate.

[0077] S2. Place the mixed substrate in a UV sterilizer at 30 μW / cm². 2 Sterilize with irradiation intensity for 30 minutes, and obtain tropical orchid cultivation substrate after sterilization.

[0078] Example 2

[0079] A tropical orchid cultivation substrate, the raw material components and proportions of which are shown in Table 1, wherein the modified pine bark is the modified pine bark prepared in Preparation Example 1; the composite modified coconut coir is the composite modified coconut coir prepared in Preparation Example 5; the porous basalt particles have a particle size of 5 mm; the biochar is coconut shell biochar with a particle size of 1 mm; and the composite amino acid chelated fertilizer is a mixture of amino acid chelated iron, amino acid chelated calcium, and amino acid chelated magnesium in a weight ratio of 2:2:3.

[0080] The above-mentioned tropical orchid cultivation substrate was prepared using the following method:

[0081] S1. Modified pine bark, composite modified coconut coir, porous basalt particles, vermiculite powder, biochar, humic acid and amino acid chelated fertilizer are placed in a mixer and mixed at a speed of 250 r / min for 18 min to obtain a mixed substrate.

[0082] S2. Place the mixed substrate in a UV sterilizer at 35 μW / cm². 2 Sterilize with irradiation intensity for 35 minutes, and obtain tropical orchid cultivation substrate after sterilization.

[0083] Example 3

[0084] A tropical orchid cultivation substrate, the raw material components and proportions of which are shown in Table 1, wherein the modified pine bark is the modified pine bark prepared in Preparation Example 1; the composite modified coconut coir is the composite modified coconut coir prepared in Preparation Example 6; the porous basalt particles have a particle size of 8 mm; the biochar is coconut shell biochar with a particle size of 2 mm; and the composite amino acid chelated fertilizer is a mixture of amino acid chelated iron, amino acid chelated calcium, and amino acid chelated magnesium in a weight ratio of 1:1:1.

[0085] The above-mentioned tropical orchid cultivation substrate was prepared using the following method:

[0086] S1. Modified pine bark, composite modified coconut coir, porous basalt particles, vermiculite powder, biochar, humic acid and amino acid chelated fertilizer are placed in a mixer and mixed at 300 r / min for 20 min to obtain a mixed substrate.

[0087] S2. Place the mixed substrate in a UV sterilizer at 40 μW / cm². 2 Sterilize with irradiation intensity for 40 minutes, and obtain tropical orchid cultivation substrate after sterilization.

[0088] Table 1. Raw material components and proportions (kg) of the cultivation substrates in Examples 1-3

[0089] raw material Example 1 Example 2 Example 3 Modified pine bark 40 50 60 Composite modified coconut coir 25 30 35 Porous basalt particles 8 10 12 Vermiculite powder 3 5 6 Biochar 4 6 8 humic acid 2 3 5 Amino acid chelated fertilizer 1 2 3

[0090] Example 4

[0091] A tropical orchid cultivation substrate, which differs from Example 2 in that the modified pine bark used in this example is the modified pine bark prepared in Preparation Example 2.

[0092] Example 5

[0093] A tropical orchid cultivation substrate, which differs from Example 2 in that the modified pine bark used in this example is the modified pine bark prepared in Preparation Example 3.

[0094] Example 6

[0095] A tropical orchid cultivation substrate, which differs from Example 2 in that the compound amino acid chelated fertilizer in this example is a mixture of amino acid chelated iron and amino acid chelated calcium in a weight ratio of 1:1.

[0096] Comparative Example

[0097] Comparative Example 1

[0098] A cultivation substrate was prepared according to Example 1 in the patent application document with publication number CN114931081A entitled "A Tropical Orchid Cultivation Substrate and Its Method of Use".

[0099] Comparative Example 2

[0100] A tropical orchid cultivation substrate, which differs from Example 2 in that an equal amount of decomposed pine bark is used instead of modified pine bark in this example.

[0101] Comparative Example 3

[0102] A tropical orchid cultivation substrate, which differs from Example 2 in that an equal amount of unmodified coconut coir is used instead of composite modified coconut coir in this example.

[0103] Comparative Example 4

[0104] A tropical orchid cultivation substrate, which differs from Example 2 in that porous basalt particles are not added in this example, and modified pine bark is used instead.

[0105] Performance testing

[0106] (a) Testing of air permeability related indicators

[0107] 1. Total porosity testing

[0108] Operating method: The ring cutter method was used for testing. A ring cutter with an inner diameter of 5 cm and a height of 5 cm was selected, and its mass m0 (unit: g) was recorded. The ring cutter was vertically pressed into the substrate to be tested, so that the substrate filled the ring cutter. Excess substrate at both ends of the ring cutter was scraped off, and the total mass m1 (unit: g) of the ring cutter and substrate was recorded. All the substrate inside the ring cutter was removed and dried in an oven at 105℃ until constant weight, and the mass m2 (unit: g) of the dried substrate was recorded. The total porosity was calculated according to the formula: Total porosity (%) = [1 - (m2 - m0) / (V × ρ0)] × 100%, where V is the volume of the ring cutter (V = πr²h, r = 2.5 cm, h = 5 cm, calculated to be V ≈ 98.125 cm³), and ρ0 is the density of the substrate (the density of the dried substrate, unit: g / cm³). Three parallel tests were set up for each group of samples, and the average value was taken. The results are shown in Table 2.

[0109] 2. Ventilation porosity testing

[0110] Operating method: Based on the total porosity test, the procedure was carried out. A ring sampler filled with the test matrix was placed in a tray filled with water, ensuring the water level was 1 cm above the bottom of the ring sampler. It was soaked for 24 hours until the matrix was saturated with water. The ring sampler was removed, the surface water was drained, and the mass of the ring sampler plus saturated matrix was measured as m3 (g). The saturated matrix inside the ring sampler was removed and dried at 105℃ to constant weight. The mass of the dried matrix was measured as m2 (g). The water-holding porosity was calculated using the following formulas: Water-holding porosity (%) = [(m3 - m0 - m2) / V] × 100%; Aeration porosity (%) = Total porosity - Water-holding porosity. Three parallel tests were conducted for each sample group, and the average value was taken. The results are shown in Table 2.

[0111] (II) Testing of water retention-related indicators

[0112] 1. Saturated water absorption rate test

[0113] Procedure: Weigh out the dry matrix to be tested, mass m4 (g), place it in a beaker, add deionized water until the matrix is ​​completely submerged, and soak for 24 hours until saturated with water. Filter with gauze, drain the surface until no water drips, and weigh out the matrix mass m5 (g) after saturation. Calculate the saturated water absorption rate using the formula: Saturated water absorption rate (%) = [(m5-m4) / m4] × 100%. Three parallel tests were set up for each group of samples, and the average value was taken. The results are shown in Table 2.

[0114] 2.24h water retention rate test

[0115] Operating method: Take the saturated water-absorbing substrate (mass m5) and place it in a constant temperature and humidity chamber at 25℃ and 60% relative humidity for 24 hours; after removal, weigh the substrate mass m6 (unit: g). Calculate the 24-hour water retention rate according to the formula: 24-hour water retention rate (%) = [(m6-m4) / (m5-m4)] × 100%. Three parallel tests were set up for each group of samples, and the average value was taken. The results are shown in Table 2.

[0116] Table 2 Detection Results

[0117] Test sample Total porosity (%) Ventilation porosity (%) Water-holding porosity (%) Saturated water absorption rate (%) 24-hour water retention rate (%) Example 1 68.5 30.2 38.3 285.3 86.7 Example 2 72.3 33.5 38.8 302.5 88.2 Example 3 70.8 32.1 38.7 298.6 87.5 Example 4 73.1 34.2 38.9 305.1 88.5 Example 5 71.9 33.8 38.1 301.2 87.9 Example 6 72.5 33.6 38.9 303.3 88.1 Comparative Example 1 62.4 22.5 39.9 265.8 75.3 Comparative Example 2 55.8 18.3 37.5 245.2 72.6 Comparative Example 3 60.2 20.1 40.1 270.5 70.3 Comparative Example 4 65.6 25.3 40.3 258.7 73.1

[0118] The test results for total porosity and aeration porosity show that the total porosity of Examples 1-6 all reached 68.5%-73.1%, and the aeration porosity was between 30.2%-34.2%, significantly higher than that of Comparative Examples 1-4. This indicates that the cultivation substrate of this application effectively optimizes the pore structure of the substrate by using modified pine bark, composite modified coconut coir, and the reasonable addition of porous basalt particles. The multi-level pore structure constructed by the modified pine bark, with its micron-sized macropores forming the main aeration channels that penetrate the substrate, provides good aeration performance. The porous basalt particles further enhance the aeration and drainage of the substrate, ensuring that the aeration porosity remains stably within a suitable range while maintaining a certain water retention capacity, thus solving the problem in existing technologies where the aeration is insufficient to meet the aerial rooting requirements of tropical orchids. In Comparative Example 2, decomposed pine bark was used instead of modified pine bark; in Comparative Example 3, unmodified coconut coir was used instead of composite modified coconut coir; and in Comparative Example 4, no porous basalt particles were added. These changes all resulted in a significant reduction in the total porosity and aeration porosity of the matrix, indicating that modified pine bark, composite modified coconut coir, and porous basalt particles play a key role in improving the aeration of the matrix.

[0119] Regarding water retention, the saturated water absorption rates of Examples 1-6 ranged from 285.3% to 305.1%, and the 24-hour water retention rates ranged from 86.7% to 88.5%, both superior to Comparative Examples 1-4. This is attributed to the special modification treatment of the composite modified coconut coir. The amino and hydroxyl groups of chitosan form a hydrogen bond network, enhancing the water retention of the coconut coir. Simultaneously, the submicron-sized mesopores and nano-sized micropores in the modified pine bark act as temporary water storage units, adsorbing and storing appropriate amounts of water, achieving uniform water conduction within the matrix through capillary action. Furthermore, vermiculite powder also contributes to water retention. The synergistic effect of multiple components results in excellent water retention performance of the matrix. Comparative Examples 2 and 3, due to the lack of modification treatment on the pine bark and coconut coir respectively, exhibited decreased water retention. Comparative Example 4, lacking the addition of porous basalt particles, had a relatively small impact on water retention, but its overall water retention performance was still inferior to the examples, further illustrating the importance of the rational combination of components in this application for water retention.

[0120] Comparing Examples 2, 4, and 5, Examples 4 and 5 used modified pine bark prepared in different ways. The test results show that the total porosity, air porosity, saturated water absorption rate, and 24-hour water retention rate of Examples 4 and 5 are slightly higher than those of Example 2. This is because the different preparation examples differ in parameters such as sodium hydroxide solution concentration, soaking time, silica sol concentration, template agent composition, and calcination temperature. These differences affect the formation and performance of the hierarchical pore structure of the modified pine bark. More precise preparation parameters result in a more ideal hierarchical pore structure in the modified pine bark, thereby further improving the air permeability and water retention of the matrix, indicating that the preparation process of the modified pine bark has a significant impact on the matrix performance.

[0121] The difference between Example 6 and Example 2 lies in the composition of the compound amino acid chelated fertilizer. The test results show little difference between the two in terms of air permeability and water retention. This indicates that in the cultivation substrate of this application, the amino acid chelated fertilizer mainly provides nutrients and has little impact on the substrate's air permeability and water retention. The cultivation substrate of this application, through the synergistic effect of modified pine bark, compound modified coconut coir, and porous basalt particles, has effectively solved the problem of simultaneously achieving good air permeability and water retention. Changes in the composition of the amino acid chelated fertilizer do not significantly affect these two key properties, further verifying the effectiveness of the technical solution in addressing the core problem.

[0122] A comprehensive comparative analysis of the test results from the integrated embodiments and comparative examples shows that the tropical orchid cultivation substrate of this application exhibits significant advantages in both air permeability and water retention. Compared with the prior art (Comparative Example 1), this application successfully solves the core problem of the difficulty in simultaneously achieving both air permeability and water retention through innovative raw material combinations and special modification treatments, providing a more suitable environment for the growth of tropical orchids. Compared with Comparative Examples 2-4, it further demonstrates that the rational selection and combination of the components in this application is key to improving substrate performance. The cultivation substrate of this application can better adapt to the dynamic needs of tropical orchids at different growth stages for air permeability and water retention, helping to improve the survival rate of cultivation and the quality of finished flowers, and promoting the standardization and large-scale development of the tropical orchid cultivation industry.

[0123] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A hot house orchid growing medium, characterized in that, Raw materials in parts by weight include: modified pine bark 40-60 parts; composite modified coconut shell 25-35 parts; porous basalt particles 8-12 parts; vermiculite powder 3-6 parts; biochar 4-8 parts; humic acid 2-5 parts; amino acid chelated fertilizer 1-3 parts; The modified pine bark is composted pine bark obtained by loading template and gradient roasting; The composite modified coconut shell is coconut shell modified by chitosan-aluminum ion composite solution and then dried.

2. A hot house orchid culture medium according to claim 1, wherein The modified pine bark is prepared by the following method: A1, soak the composted pine bark in sodium hydroxide solution at 60-70℃ for 2-3h, then wash with deionized water until neutral, and dry at 65-75℃ until constant weight to obtain defatted pine bark; A2, soak the defatted pine bark in precursor solution, then add template agent, soak at room temperature for 12-16h, ultrasonic treatment 2-4 times, 30min each time, then take out and dry to obtain template loaded pine bark; A3, place the template loaded pine bark in a programmed temperature furnace, heat to 350-400℃, keep for 2-3h, then heat to 550-600℃, keep for 2-3h, then naturally cool to room temperature, soak in 10%-15% hydrofluoric acid solution for 30-60min to remove the template, wash with deionized water until neutral, and dry to obtain modified pine bark.

3. A hot house orchid growing medium as claimed in claim 2, wherein, In the A1 step, the mass concentration of the sodium hydroxide solution is 5%-10%, and the mass ratio of the composted pine bark to the sodium hydroxide solution is 1:8-12.

4. The epiphytic orchid culture medium according to claim 2, wherein In the A2 step, the precursor solution is silica sol with a mass concentration of 8%-12%, and the mass ratio of the defatted pine bark to the silica sol is 1:10-15.

5. A hot house orchid growing medium as claimed in claim 4, wherein, In the A2 step, the template agent is a mixture of polyethylene glycol-400 and cetyltrimethylammonium bromide with a weight ratio of 3-5:1, and the addition amount of the template agent is 5%-8% of the mass of the silica sol.

6. The epiphytic orchid culture medium according to claim 1, wherein The composite modified coconut shell is prepared by the following method: Soak the coconut shell in chitosan-aluminum ion composite solution at room temperature for 8-10h, then take out and dry in a 55-65℃ oven until the moisture content is 10%-12% to obtain the composite modified coconut shell.

7. A hot house orchid growing medium as defined in claim 6, wherein: The chitosan-aluminum ion composite solution is a mixed solution prepared by mixing chitosan solution with a mass concentration of 0.8%-1.5% and aluminum nitrate solution with a mass concentration of 0.8%-1.6% at a volume ratio of 1:1, and the mass ratio of the coconut shell to the chitosan-aluminum ion composite solution is 1:6-10.

8. The epiphytic orchid culture medium according to claim 1, wherein The porous basalt particles have a particle size of 3-8mm and a porosity of 45%-55%, and the biochar is coconut shell biochar with a particle size of 0.5-2mm.

9. A method of preparing a thermophilic orchid culture substrate according to any one of claims 1 to 8, characterized in that, The method includes the following steps: S1, mix the modified pine bark, composite modified coconut shell, porous basalt particles, vermiculite powder, biochar, humic acid and amino acid chelated fertilizer in a mixer at a rotation speed of 200-300r / min for 15-20min to obtain a mixed base material; S2, the mixed substrate is placed in a ultraviolet sterilization box, sterilized for 30-40 min at an irradiation intensity of 30-40 μW / cm 2 After sterilization, the tropical orchid cultivation substrate is obtained.

10. Use of a Cattleya cultivation substrate according to any one of claims 1 to 8 in the cultivation of Cattleya, characterized in that, The cultivation substrate is filled into a cultivation container with a thickness of 15-25 cm, and the seedling of the tropical orchid is planted in the substrate with a planting depth of 3-5 cm to ensure that the root system is in full contact with the substrate, and then normal cultivation and maintenance are carried out.