Foaming substrate for efficient seedling culture of oak trees and preparation method and application thereof

Abstract

The invention discloses a foaming substrate for efficient seedling raising of oak trees as well as a preparation method and application of the foaming substrate. The matrix is formed by compounding a foam skeleton formed by a hydrophilic modified polyurethane soft foaming agent with turf, coco coir, perlite, a slow release fertilizer and other organic matters in a specific proportion. The preparation method comprises the following steps: mixing the solid raw materials with foaming liquid containing the hydrophilic modifier and the slow-release fertilizer, initiating a polyurethane foaming reaction, curing, curing and crushing. The matrix takes elastic foam as a framework, integrates light weight, stable structure, excellent water holding and air permeability and long-acting fertilizer supply, is particularly suitable for root growth requirements of tree species such as cork oak, Mongolian oak, quercus acutissima and mistletoe, can remarkably improve the seed germination rate, promote growth of seedling root systems and overground parts and improve the seedling quality and stress resistance, and is suitable for containerized efficient seedling culture.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forest seedling raising, and particularly relates to a foaming substrate for efficient seedling raising of Quercus species, which is mainly composed of polyurethane soft foaming material, and is compounded with grass charcoal, coconut husk, perlite, slow-release fertilizer and hydrophilic modifier. BACKGROUND

[0002] Quercus, also known as oak, is an important timber, ecological and landscape tree species in China, and its seedling raising is usually carried out by using traditional soil or light substrate.

[0003] The traditional soil substrate has problems of large weight, poor air permeability, easy compaction and more pests and diseases.

[0004] In addition, conventional light substrates are also used in cultivation, which are generally composed of pure grass charcoal and pure coconut husk. For example, a light substrate for container seedling raising of square bamboo is disclosed in patent application No. CN201611039551.4, which mainly comprises humus soil, grass charcoal and filler.

[0005] The light substrate material in the above patent has problems of unbalanced water and fertilizer retention, insufficient structural stability, root entanglement and poor air permeability when used for Quercus species with developed taproot and high requirements for air permeability and stable support during seedling stage, thereby affecting the uniformity of seedling raising and the quality of seedling raising.

[0006] Although some technologies use polyurethane soft foaming material substrate, the polyurethane soft foaming material has the characteristics of porosity, light weight, good elasticity and biodegradability, but has poor hydrophilicity and no nutrients, and is not ideal when directly used for seedling raising.

[0007] Therefore, the present application provides a foaming substrate for efficient seedling raising of Quercus species and a preparation method and application thereof. SUMMARY

[0008] To solve the above technical problems, the present application adopts the technical scheme of a foaming substrate for efficient seedling raising of Quercus species, which is prepared from the following raw materials in volume percentage: 20%-35% of a solid foam skeleton formed by hydrophilic modification and reaction of polyurethane soft foaming agent, 15%-25% of grass charcoal, 20%-30% of coconut husk, 10%-20% of perlite, 5%-10% of other organic matter, and 1%-2% of slow-release fertilizer based on the total weight of the substrate; and the addition amount of the hydrophilic modifier in the foaming agent is 0.5%-2% of the weight of the polyurethane soft foaming agent.

[0009] On the basis of any one of the above technical solutions, the grass charcoal has a particle size of 0.5-5 mm; the coconut husk is desalted; and the perlite has a particle size of 2-6 mm.

[0010] On the basis of any one of the above technical solutions, further optimization is that the other organic matter is selected from one or more of rotten sawdust, rotten straw powder and humic acid.

[0011] On the basis of any one of the above technical solutions, further optimization is that the hydrophilic modifier is a compound of polyether type non-ionic surfactant and organic silicon hydrophilic agent, and the mass ratio of the two is (3-5):1.

[0012] On the basis of any one of the above technical solutions, further optimization is that the slow-release fertilizer is a coated slow-release fertilizer with N-P-K=14-14-14 and a release period of 3-4 months.

[0013] The application also provides a method for preparing the oak efficient seedling foaming substrate as described above, comprising the following steps: (1) grass charcoal, coconut husk, perlite and other organic matters are respectively crushed and sieved, and then uniformly mixed according to the proportion to obtain a solid mixture A; (2) polyurethane soft foaming agent, hydrophilic modifier and slow-release fertilizer are uniformly mixed to obtain foaming liquid B; (3) under stirring, the solid mixture A is added into the foaming liquid B, and after uniform mixing, the isocyanate component is added, and after rapid stirring, it is poured into a mold; (4) the material is foamed and solidified at room temperature in the mold, and after demolding, it is aged to obtain a block material; (5) the aged block material is crushed or cut into particles, and the seedling substrate is obtained.

[0014] The application also provides an application of the oak efficient seedling foaming substrate as described above, and the application is that the seedling substrate is used for the cultivation of container seedlings of oak species, and the oak species includes Quercus bark, Mongolian oak, Quercus infectoria, Quercus infectoria.

[0015] The application comprises the following steps: (1) container pretreatment: hard plastic seedling containers are selected, 3-5 drainage holes with a diameter of 2-3 mm are arranged at the bottom of the container, the container is cleaned and disinfected, and then dried for standby use.

[0016] (2) substrate filling: the seedling substrate is loosely filled into the seedling container, and the filling height is 85%-90% of the volume of the container; during the filling process, the substrate is prevented from being compacted, and after filling, the surface of the substrate is lightly pressed to make the substrate adhere to the container wall.

[0017] (3) Sowing / transplanting: for Quercus variabilis and Quercus mongolica, adopt the method of sowing seeds, 1-2 full seeds per container, and cover with 0.5-1cm thick of the seedling substrate; for Quercus acutissima and Quercus aliena, adopt the method of transplanting seedlings, select healthy seedlings with a height of 3-5cm, dig a planting hole with a depth of 2-3cm in the center of the substrate, and then put the seedlings into the hole, backfill the substrate and gently press to fix.

[0018] (4) Cultivation management: place the seedling container in an environment with a temperature of 20-28℃, a relative humidity of 60%-70%, and a light intensity of 1500-2500lux, and cultivate, the watering frequency is 3-5 days / time, the watering is to 60%-70% of the saturated water content rate of the substrate, the cultivation period is 3-4 months, and no additional fertilization is needed during the cultivation period.

[0019] Compared with the prior art, the beneficial effects of the present application are as follows: 1. The present application significantly optimizes the physical structure of the oak seedling substrate, precisely matches the hydrophilic modified polyurethane foam skeleton with grass charcoal, coconut fiber and perlite, constructs a three-level pore system, and balances the high air permeability and water retention, solving the problem of traditional substrate hardening and root rot caused by waterlogging.

[0020] The substrate structure is suitable for the growth characteristics of the developed main roots of oak trees, reduces the root entanglement phenomenon, improves the uniformity of seedling cultivation, and builds a stable and suitable growth carrier for the healthy growth of seedlings, helping the full development of seedling roots.

[0021] 2. The present application realizes the precise supply of nutrients for oak seedlings, adds coated slow-release fertilizer, and cooperates with the organic components of the substrate, so that the nutrient release rate completely matches the growth period of the seedlings, and no additional fertilization is needed during the cultivation period.

[0022] The design avoids the nutrient loss and seedling burning caused by conventional fertilization, improves the overall nutrient utilization efficiency, guides the coordinated development of roots, stems and leaves of seedlings, and helps the seedlings to maintain good growth momentum after leaving the nursery.

[0023] 3. The present application greatly reduces the operation and cost input of oak seedling cultivation, the lightweight substrate characteristics significantly reduce the transportation and handling cost, and the heavy drawbacks of traditional soil substrate are avoided. The loose filling operation simplifies the seedling process, and no complex compaction process is needed, and the precise cultivation parameters reduce the frequency of manual intervention.

[0024] At the same time, the substrate can be reused, further reducing the cost of seedling materials, and adapting to the production needs of large-scale container seedling.

[0025] 4. The present application has excellent environmental sustainability, the composted sawdust and straw powder in the raw material are derived from agricultural and forestry waste, realizing resource recycling and reducing the cost of raw material acquisition.

[0026] The hydrophilic modified polyurethane foam framework can be gradually degraded in a natural environment, avoiding environmental pollution caused by residual plastic matrix. The repeated use reduces the matrix waste discharge, and both economic benefits and ecological benefits are considered.

[0027] 5. The application effectively improves the stress resistance and transplanting adaptability of oak seedlings, the stable microecological environment of the matrix construction promotes the reproduction of beneficial microorganisms, inhibits the growth of pathogenic bacteria, and reduces the probability of disease occurrence of seedlings.

[0028] The developed root system enhances the drought resistance, cold resistance and other stress resistance of seedlings, the root activity of the nursery seedlings is strong, the seedlings can quickly recover after transplanting, and can adapt to a variety of different planting scenes. DETAILED DESCRIPTION

[0029] The embodiments of the technical scheme of the application will be described in detail below. The following examples are only used to more clearly illustrate the technical scheme of the application, and therefore only serve as examples, and cannot limit the protection scope of the application.

[0030] Example 1: An efficient oak seedling foaming matrix, which is prepared from the following raw materials in volume percentage: 20%-35% of the solid foam framework formed after hydrophilic modification and reaction of polyurethane soft foaming agent, 15%-25% of grass charcoal, 20%-30% of coconut husk, 10%-20% of perlite, 5%-10% of other organic matter, and 1%-2% of slow-release fertilizer accounting for the total weight of the matrix; the addition amount of the hydrophilic modifier in the foaming agent is 0.5%-2% of the weight of the polyurethane soft foaming agent.

[0031] It should be noted that: the specific operation conditions of the hydrophilic modification are: the hydrophilic modifier and the polyurethane soft foaming agent are stirred and mixed at a constant temperature of 35-40℃ and a stirring speed of 200-300r / min for 20-30 minutes to ensure that the modifier is uniformly dispersed in the foaming agent.

[0032] The reaction system parameters of the solid foam framework formed after the reaction are: the weight ratio of polyurethane soft foaming agent to isocyanate component is 1:1.2-1:1.5, the reaction temperature is controlled at 25-30℃, and the reaction time is 30-60 minutes, which ensures that the foam framework is fully crosslinked and shaped, while avoiding excessive heat release to damage other components of the matrix.

[0033] In the late stage of the mixing stage of the matrix preparation, the slow-release fertilizer is added in a step-by-step manner with stirring at 150-200r / min to ensure uniform distribution of the slow-release fertilizer and avoid local high concentration from burning the seedling roots.

[0034] The hydrophilic modified polyurethane solid foam skeleton serves as a core support structure, and its porous structure can provide good air permeability, while the modified hydrophilic groups can improve the water absorption capacity; the grass charcoal and coconut fiber serve as core components for water and fertilizer retention, the high humus content of the grass charcoal can improve the fertility of the substrate, and the fibrous structure of the desalted coconut fiber can enhance the water retention, and the two are compounded in proportion to balance the water retention and air permeability.

[0035] In addition, the porous structure of perlite can further optimize the pore structure of the substrate, improve the air permeability, and enhance the drainage of the substrate to avoid waterlogging and root rot. The pore adjustment of perlite optimizes the pore matching of the foam skeleton and organic components, meets the growth needs of oak main roots, and requires high air permeability and stable support during the seedling stage.

[0036] The increase in the macroporosity and mesoporosity of the pore structure of the substrate can promote the downward growth of oak main roots, reduce root entanglement, and increase the length of main roots compared to conventional light substrates.

[0037] Combining polyurethane foam skeleton with organic substrate components not only improves the effect of oak seedling cultivation, but also can be reused. The substrate can be reused 2-3 times after simple screening (removal of root residues), and the survival rate of seedlings can still be maintained at a high level. In addition, the substrate can be naturally degraded after the end of the seedling period, avoiding the environmental pollution problem of traditional plastic substrates.

[0038] On the basis of any of the above technical solutions, further optimization is that the particle size of the grass charcoal is 0.5-5mm; the coconut fiber is desalted coconut fiber; the particle size of the perlite is 2-6mm.

[0039] It should be noted that the particle size of the grass charcoal is controlled at 0.5-5mm, which can balance the water retention and air permeability. If the particle size is too large, the water retention area will decrease and the water retention will decrease; if the particle size is too small, the substrate pore will be too small and the air permeability will be poor.

[0040] The particle size of the perlite is controlled at 2-6mm, which is larger than that of the grass charcoal, and can form a large pore channel in the substrate, forming a hierarchical pore structure with the small and medium pores of the grass charcoal, further improving the air permeability and drainage performance of the substrate, and avoiding root hypoxia caused by water accumulation. In addition, from the perspective of chemical environment, the original coconut fiber contains high salt content mainly in the form of sodium chloride and potassium chloride. If not desalted, the accumulation of salt in the substrate will cause imbalance of root osmotic pressure and cause seedling burn. Desalted coconut fiber can create a mild root growth chemical environment, and adjust the pH value to adapt to the acid-base needs of oak seedling growth, improving the survival rate of seedlings.

[0041] The fine particles of grass charcoal and coconut coir can fill part of the pores of the foam framework, improve the water and fertilizer retention capacity of the substrate, and avoid rapid loss of water and nutrients due to excessively large pores; the coarse particles of perlite can support the foam framework, avoid the collapse of the foam framework under pressure, and at the same time enhance the structural stability of the substrate.

[0042] In addition, the fiber structure of desalted coconut coir can adsorb and release the nutrients released by the slow-release fertilizer, avoid rapid loss of nutrients, and improve the utilization rate of nitrogen; The use of desalted coconut coir can also reduce the water consumption for flushing salt in the later watering, at the same time, improve the survival rate of seedlings, and reduce the cost of seedling and reseeding.

[0043] On the basis of any of the above technical solutions, further optimization is that the other organic matter is selected from one or more of compost sawdust, compost straw powder and humic acid.

[0044] It should be noted that by selecting specific composted organic matter or humic acid, the demand of oak seedling growth for organic matter and the problem of substrate micro-ecological balance are solved in cooperation with existing substrate components. Composted sawdust and composted straw powder are rich in cellulose, hemicellulose decomposition products and a small amount of available nutrients such as nitrogen, phosphorus and potassium, which can be used as a supplement to slow-release fertilizer to continuously provide nutrients for seedling growth; at the same time, organic acids can be released during the decomposition process to adjust the pH value of the substrate, further adapting to the growth requirements of oak trees.

[0045] On the basis of any of the above technical solutions, further optimization is that the hydrophilic modifier is a compound of polyether nonionic surfactant and organic silicon hydrophilic agent, and the mass ratio of the two is (3-5):1.

[0046] It should be noted that the compounding process parameters of the compound are as follows: the polyether nonionic surfactant and the organic silicon hydrophilic agent are added to the reaction kettle with constant temperature stirring device in a mass ratio of (3-5):1, stirred at a speed of 250-300 r / min for 30-40 minutes in a constant temperature environment of 40-45℃, and protected by nitrogen gas (flow rate 10-20 mL / min) during stirring to avoid oxidation of the organic silicon hydrophilic agent; after compounding, the appearance of the hydrophilic modifier is light yellow transparent liquid.

[0047] In addition, the hydrophilic segment of the polyether nonionic surfactant is adsorbed on the surface of the polyurethane foaming agent molecule, reducing the surface tension of the foaming agent and improving its initial water adsorption capacity; the amino functional group of the organic silicon hydrophilic agent reacts with the hydroxyl group in the polyurethane foaming agent molecule to form a stable chemical bond, anchoring the hydrophilic group in the polyurethane molecular structure, avoiding the shedding of the hydrophilic group, and improving the durability of the modification.

[0048] The hydrophilic performance of the modified polyurethane foam framework is improved, the adsorption and conduction capacity of water and nutrients in the grass charcoal and coconut coir can be enhanced, the water can be quickly conducted from the foam framework to the grass charcoal and coconut coir, and then absorbed by the seedling root system; meanwhile, the hydrophilic foam framework can reduce the loss of water on the surface of the substrate, improve the water utilization rate, and reduce the watering frequency.

[0049] On the basis of any one of the above technical solutions, further optimization is that the slow-release fertilizer is a coated slow-release fertilizer with N-P-K=14-14-14 and a release period of 3-4 months.

[0050] The N-P-K=14-14-14 slow-release fertilizer is a balanced slow-release fertilizer with nitrogen, phosphorus and potassium content of 14%, which can slowly release nutrients to meet the needs of plants at different growth stages, and belongs to mature prior art, and is widely used in the fields of horticulture, agriculture and the like.

[0051] Embodiment 2: Compared with embodiment 1, the difference is that the following technical features are further included: The application further provides a method for preparing the efficient seedling raising foaming substrate for oak trees, comprising the following steps: (1) crushing and sieving the grass charcoal, coconut coir, perlite and other organic matters respectively, and uniformly mixing them according to the proportion to obtain a solid mixture A; The feeding sequence is: first, the grass charcoal and coconut coir are fed, stirring for 10 minutes, then the perlite is fed, stirring for 5 minutes, finally the other organic matters are fed, and stirring for 10-15 minutes, the total mixing time is 25-30 minutes; during the mixing process, the uniformity is detected every 5 minutes to ensure uniform mixing. The light component is fed first, and then the heavy component is fed, which can avoid uneven mixing caused by the settlement of the heavy component; accurate control of the mixing time can balance the mixing effect and energy consumption, and avoid uneven distribution of components caused by insufficient mixing or damage to component particles caused by excessive mixing.

[0052] In addition, the uniform solid mixture A can make the reaction degree of each region consistent during the subsequent curing process, and avoid unstable substrate performance caused by local insufficient curing.

[0053] (2) uniformly mixing the polyurethane soft foaming agent, the hydrophilic modifier and the slow-release fertilizer to obtain a foaming liquid B; Mixing sequence and operation steps: first, add the polyurethane soft foaming agent into the stirred tank, raise the temperature to 35-40℃, and stir for 10 minutes to stabilize the temperature of the foaming agent; second, slowly add the pre-compounded hydrophilic modifier into the stirred tank (addition rate 5-10 L / h), stirring while adding, and continue stirring for 20 minutes after adding; third, add the slow-release fertilizer in 3-4 times (each addition amount is not more than 30% of the total weight), stir for 5-10 minutes after each addition, and ensure that the slow-release fertilizer is uniformly dispersed in the foaming liquid to avoid particle sedimentation; the total mixing time is 45-60 minutes.

[0054] The purpose of this step is to precisely mix the polyurethane soft foaming agent, hydrophilic modifier, and slow-release fertilizer to form a stable foaming liquid B, laying a foundation for the subsequent reaction with the solid mixture A and the formation of the foam skeleton, while ensuring the uniform dispersion of the slow-release fertilizer to provide protection for the uniform release of nutrients in the future.

[0055] Adding the slow-release fertilizer in 3-4 times and combining with low-speed stirring of the anchor stirrer can break the agglomeration structure of the slow-release fertilizer particles by using the shear force generated by stirring, so that the 1-2 mm coated slow-release fertilizer is uniformly suspended in the foaming liquid.

[0056] The constant temperature control of 35-40℃ can precisely match the reaction activity range of the polyurethane soft foaming agent, avoiding premature self-polymerization of the foaming agent due to high temperature, and preventing insufficient dissolution of the modifier and decreased dispersibility of the slow-release fertilizer due to low temperature.

[0057] In addition, the suspended slow-release fertilizer particles can form a closer combination with components such as peat and coconut coir when mixed with the solid mixture A in the future, further improving the nutrient retention capacity.

[0058] It has strong synergistic adaptability with the subsequent process, the foaming liquid B prepared in this step can quickly react with the isocyanate component in step (3), the pre-associated hydrophilic group can be directionally arranged on the pore surface during the formation of the foam skeleton, making the hydrophilic performance of the final substrate more durable; the uniformly dispersed slow-release fertilizer can be wrapped in the combination interface between the foam skeleton and the solid mixture A during the formation of the foam pores, without affecting the cross-linking and molding of the foam skeleton, and can slowly release nutrients through water infiltration during the seedling raising process; at the same time, the stable system of the foaming liquid B can quickly infiltrate and combine with components such as peat and coconut coir in the solid mixture A, avoiding the phenomenon of liquid-solid stratification, and improving the molding efficiency of the substrate.

[0059] (3) Add the solid mixture A into the foaming liquid B under stirring, mix uniformly, then add the isocyanate component, and pour into the mold after rapid stirring; The first stage (solid A is added to the foaming liquid B, low-speed stirring): the role is to infiltrate and disperse, the shear force generated by the low-speed stirring of 200-250 r / min can break the liquid film barrier on the surface of the solid particles, so that the polyurethane molecules, the hydrophilic modifier and the slow-release fertilizer in the foaming liquid B can fully wrap the solid particles such as grass charcoal and coconut fiber; the porous structure of the grass charcoal and the coconut fiber can absorb the water and the modifier in the foaming liquid, and form an adsorption complex of the solid particles-liquid components, so as to avoid separation of the solid particles and the foam skeleton in the subsequent foaming process; the slow-release fertilizer particles are uniformly embedded in the adsorption complex by the stirring force, and the dispersion stability is further improved.

[0060] The second stage (isocyanate is added, high-speed rapid stirring): the role is to start cross-linking and foaming, the isocyanate and the hydroxyl in the polyurethane soft foaming agent rapidly occur polycondensation reaction, and CO2 gas is released at the same time; high-speed stirring can disperse the generated CO2 gas into small bubbles, so as to ensure that the bubbles are uniformly distributed in the material system.

[0061] The third stage (stirring and then pouring into a mold): the role is to shape and prepare - after the uniform foaming material is poured into the pretreated mold, a regular shape can be formed by the boundary constraint of the mold; the air-permeable non-woven fabric at the bottom of the mold can discharge a small amount of gas remaining in the foaming process, so as to avoid local pores being too large due to the aggregation of the bubbles; the release agent can reduce the adhesion between the material and the mold wall, so as to provide protection for subsequent demolding.

[0062] The synergistic effect of this step and the previous and subsequent processes is strong: on the one hand, the uniform mixing of this step can fully exert the particle size advantage (0.5-5 mm grass charcoal, 2-6 mm perlite) of the solid mixture A in step (1), so that the solid particles form hierarchical pores in the foam skeleton, and the air permeability and water balance of the substrate are further optimized; on the other hand, the uniform dispersion effect of the slow-release fertilizer in the foaming liquid B in step (2) can be ensured, so as to avoid the slow-release fertilizer from settling and aggregating in the reaction process, and to ensure that the nutrients are supplied to the oak seedlings in a balanced manner.

[0063] (4) The material is foamed and solidified at room temperature in the mold, and then demolded and aged to obtain a block material. Segmented time control of foaming and solidification: after the material is poured into the mold, it is left to stand for 2-3 hours, which is the foaming reaction period of the polyurethane prepolymer and the isocyanate, and the CO2 gas slowly expands to form uniform bubbles, so it is necessary to ensure that the environment is not shaken violently to avoid the bubbles being broken or deformed; at this time, the grass charcoal and coconut fiber particles in the solid mixture A are uniformly embedded in the gaps of the foam skeleton by the expansion force generated in the foaming process, and the rigid particles of the perlite play a role in supporting the bubbles to avoid the structure from collapsing due to excessive expansion of the bubbles; in addition, the slow-release fertilizer particles are tightly wrapped by the foam skeleton and the solid components to form a nutrient storage.

[0064] After foaming is completed, continue to stand for 12-16 hours, in this stage, the prepolymer completes crosslinking reaction to form a stable three-dimensional mesh foam skeleton.

[0065] At the same time, the components such as grass charcoal and coconut fiber in the solid mixture A complete interface combination with the foam skeleton, and the judgment standard for the solidification end point is that there is no indentation when the surface of the block material is pressed, and there is no deformation after demolding.

[0066] (5) crushing or cutting the block material after maturation into particles, thereby obtaining the seedling substrate.

[0067] Embodiment 3: Compared with Embodiment 2, the difference lies in that the following technical features are further included: The application also provides a use of the efficient seedling foaming substrate for oak trees, and the use is that the seedling substrate is used for cultivation of container seedlings of Quercus species, and the Quercus species includes Quercus Verrucosa, Quercus mongolica, Quercus acutissima and Quercus aliena.

[0068] The use includes the following steps: (1) container pretreatment: hard plastic seedling containers are selected, 3-5 drainage holes with a diameter of 2-3 mm are arranged at the bottom of the container, the container is cleaned and disinfected, and then dried for standby.

[0069] (2) substrate filling: the seedling substrate is loosely filled into the seedling container, the filling height is 85%-90% of the volume of the container, the substrate is prevented from being compacted during the filling process, and the surface of the substrate is lightly pressed after filling to make the substrate adhere to the container wall.

[0070] (3) sowing / transplanting: for Quercus Verrucosa and Quercus mongolica, the seed sowing method is adopted, 1-2 full seeds are sown in each container, and 0.5-1 cm thick seedling substrate is covered; for Quercus acutissima and Quercus aliena, the seedling transplanting method is adopted, healthy seedlings with a height of 3-5 cm are selected, a planting hole with a depth of 2-3 cm is dug in the center of the substrate, and the seedling is placed in the hole, and then the substrate is backfilled and lightly pressed to fix it.

[0071] (4) cultivation management: the seedling container is placed in an environment with a temperature of 20-28 DEG C, a relative humidity of 60%-70%, and a light intensity of 1500-2500 lux for cultivation, the watering frequency is 3-5 days / time, the watering is performed until the substrate saturated water content is 60%-70%, the cultivation period is 3-4 months, and no additional fertilization is required during the cultivation period.

[0072] In the cultivation management link: the light environment needs to be supplemented with light for 10-12 hours per day, LED plant growth lamps are used for regulation, and direct strong light is avoided; the watering method is slow irrigation along the container wall, direct flushing of the substrate surface is prohibited, and the substrate is prevented from being hardened; the temperature and humidity control equipment is selected to be an intelligent seedling greenhouse control cabinet, the temperature deviation is controlled to be ±1 DEG C, and the humidity deviation is controlled to be ±5%.

[0073] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application is described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; any alternative improvement or change made by those skilled in the art to the embodiments of the present application falls within the protection scope of the present application.

[0074] The parts not described in detail in the present application are known to those skilled in the art.

Claims

1. A high-efficiency foamed substrate for oak seedling cultivation, characterized in that, It is prepared from the following raw materials by volume percentage: The foaming agent consists of a solid foam skeleton formed by hydrophilic modification and reaction of polyurethane flexible foaming agent (20%-35%), peat moss (15%-25%), coconut coir (20%-30%), perlite (10%-20%), other organic matter (5%-10%), and slow-release fertilizer accounting for 1%-2% of the total weight of the matrix; the amount of hydrophilic modifier added to the foaming agent is 0.5%-2% of the weight of polyurethane flexible foaming agent.

2. The high-efficiency foamed substrate for oak seedling cultivation according to claim 1, characterized in that: The peat moss has a particle size of 0.5-5 mm; the coconut coir is desalinated coconut coir; and the perlite has a particle size of 2-6 mm.

3. The high-efficiency foamed substrate for oak seedling cultivation according to claim 2, characterized in that: The other organic matter is selected from one or more of decomposed sawdust, decomposed straw powder, and humic acid.

4. The high-efficiency foamed substrate for oak seedling cultivation according to claim 3, characterized in that: The hydrophilic modifier is a compound of polyether-type nonionic surfactant and organosilicon hydrophilic agent, with a mass ratio of (3-5):

1.

5. The high-efficiency foamed substrate for oak seedling cultivation according to claim 4, characterized in that: The slow-release fertilizer is a coated slow-release fertilizer with NPK=14-14-14 and a release period of 3-4 months.

6. A method for preparing a high-efficiency foamed substrate for oak seedling cultivation as described in any one of claims 1-5, characterized in that, Includes the following steps: (1) After crushing and sieving peat moss, coconut coir, perlite and other organic matter, they are mixed evenly in proportion to obtain solid mixture A; (2) Mix the polyurethane soft foaming agent, hydrophilic modifier and slow-release fertilizer evenly to obtain foaming liquid B; (3) Add solid mixture A to foaming liquid B under stirring, mix evenly, add isocyanate component, stir quickly and pour into mold; (4) The material foams and solidifies in the mold at room temperature, and is cured after demolding to obtain a block material; (5) The matured block material is crushed or cut into particles to obtain the seedling substrate.

7. An application of the high-efficiency foamed substrate for oak seedling cultivation as described in any one of claims 1-5, wherein the application is to use the seedling substrate for the cultivation of container seedlings of oak species, including cork oak, Mongolian oak, quince, and oak.