Slope greening spray-seeding substrate and preparation method thereof

Abstract

The invention discloses a side slope greening spray-seeding substrate and a preparation method thereof, and relates to the technical field of spray-seeding substrates. The slope greening spray-seeding substrate comprises soil, plant fibers, rice husk charcoal, walnut shells, water glass, polyvinyl alcohol, borax or boric acid, fertilizer, a water-retaining agent and water. According to the slope greening spray-seeding substrate, the adopted materials are environment-friendly, such as coco coir soil, rice husk charcoal, walnut shells and the like, and all belong to biological materials; the water glass belongs to an inorganic non-metallic material, not only can play a bonding role, but also can be used as a fertilizer in the vegetation growth process; the polyvinyl alcohol has good natural degradation performance and also does not influence the environment. Meanwhile, by means of the spray-seeding substrate, vegetation has the high germination rate, and meanwhile the spray-seeding substrate can be suitable for a side slope with the gradient of 78 degrees.

Description

Technical Field

[0001] The invention relates to the technical field of spraying substrates, and in particular to a slope greening spraying substrate and a preparation method thereof. Background Art

[0002] In recent years, the accelerated pace of development and urbanization has led to an increasing contradiction between urban construction and ecological protection. In the process of infrastructure construction such as roads, railways, water conservancy and municipal facilities, a large amount of mountain digging and leveling, quarrying and soil extraction have not only destroyed the topography and native vegetation, but also formed a large number of mountain fracture zones with exposed slopes as the main feature. This has had an extremely adverse impact on soil and water conservation and ecological protection, urban landscape and human living environment. Therefore, it is urgent to manage and green the exposed slopes and mountain gaps.

[0003] Spraying technology is a technology for transforming slopes and mountains. It mainly uses a sprayer to spray artificial soil matrix and plant seeds onto slopes and mountains to form an artificial soil layer. Plant seeds can germinate in the artificial soil layer, and then green the slopes and mountains. For spraying technology, the spraying matrix is ​​the focus, which is related to the growth of vegetation. The spraying matrix usually includes soil, binder, water retainer, fertilizer, etc. In some cases, according to actual conditions, corresponding organic matter can also be added to increase the fertility of the matrix. Chinese patent 201910761958.5 discloses a red mud spraying matrix, which uses polyacrylamide as a binder and cross-linked sodium polyacrylate as a water retainer. Although it can achieve the purpose of soil spraying to a certain extent, the amount of water retainer and binder selected is relatively large, and both are substances that are difficult to degrade naturally, and the environmental protection performance is relatively poor. Summary of the invention

[0004] In view of the above technical problems, the purpose of the present invention is to provide a slope greening spraying matrix and a preparation method thereof in view of the defects of the prior art.

[0005] The present invention adopts the following technical scheme: a slope greening spraying matrix, which comprises, by weight, 1000 parts of soil, 50-200 parts of plant fiber, 30-80 parts of rice husk charcoal, 1-10 parts of walnut shells, 1-5 parts of water glass, 2-7 parts of polyvinyl alcohol, 0.01-0.1 parts of borax or boric acid, 5-15 parts of fertilizer, 0.8-2 parts of water retaining agent, and 250-650 parts of water.

[0006] Specifically, in the present invention, the soil can be conventional soil, such as common loess, loam, etc., and sandy soil should be avoided as much as possible. The overall selection principle is similar to the selection principle of soil for conventional soil spraying. At the same time, a certain amount of loam and sandy soil can be compounded to reduce the amount of loam used. The compounding amount of the two needs to be determined based on the sand content in the loam. Generally speaking, the amount of sand added does not exceed 30% of the loam mass.

[0007] Similar to conventional methods, the soil in the present invention also needs to remove large particles of impurities in the soil before use, and at the same time remove as much water as possible so that the remaining substances can be fully mixed with the soil.

[0008] Plant fiber, rice husk charcoal and walnut shell are organic matter added to the matrix. Among them, plant fiber and walnut shell can also increase the strength of the matrix, and walnut shell is a common bioreinforcement material. When it is used, it usually needs to be crushed to a particle size of no more than 3mm; rice husk charcoal can not only increase the carbon content in the matrix, but also is a loose and porous material. Adding it to the matrix can also enhance the air permeability of the matrix, thereby improving the growth of the preparation, especially when the soil used is relatively sticky, the amount of rice husk charcoal added can be appropriately increased.

[0009] For water glass and polyvinyl alcohol, they belong to binding agents, and are different from conventional spraying substrates. The inventor has found after a large number of tests that after water glass and polyvinyl alcohol are compounded, when the addition amount is relatively low, the substrate can have good bonding properties. Meanwhile, since polyvinyl alcohol belongs to a water-soluble binding agent, if directly used, it is easily dissolved in rainwater under the scouring of rainwater, causing the bonding properties of the substrate to decline, eventually causing the substrate to lose and fall off, and the greening effect is greatly reduced. Therefore, the inventor makes the polyvinyl alcohol water-soluble variation in the substrate worse by adding a trace cross-linking agent, thereby reducing its loss amount under rainwater conditions.

[0010] As for polyvinyl alcohol, polyvinyl alcohols with relatively high molecular weights can be used in the present invention. For example, for some high molecular weight polyvinyl alcohols, a higher alcoholysis degree is required, and for low molecular weight polyvinyl alcohols, a relatively low alcoholysis degree is required.

[0011] There are many cross-linking agents for polyvinyl alcohol, such as common aldehydes and borax. However, the inventors found that aldehyde cross-linking agents, such as glutaraldehyde, have a greater impact on vegetation seeds, and even a small amount of addition will greatly reduce the germination rate of seeds. For this reason, the inventors selected borax as the cross-linking agent for polyethylene glycol.

[0012] One embodiment of the present invention is that the plant fiber is one of coconut chaff, bagasse, and fermented straw, and the length of the bagasse and the straw is not more than 3 cm. Coconut chaff, bagasse, and fermented straw are all common plant fibers. For coconut chaff, although its length is long, its diameter is small, so it does not affect the use; but for bagasse and straw, their sizes are large and small, and they also contain some hard outer skins, so they need to be sheared to make them better mixed with the rest of the substances in the matrix. At the same time, in the current resource utilization process of straw and bagasse (such as feed, compost, etc.), they usually need to be crushed, so the specific crushing process is not described here.

[0013] In one embodiment of the present invention, the water retaining agent is a polyacrylic acid gel or a polyacrylamide gel. The gel refers to cross-linked polyacrylic acid or polyacrylamide particles, which can absorb water and swell, and the maximum water absorption can reach dozens of times, and are common water retaining agents in the field.

[0014] Preferably, the preparation method of the water retaining agent comprises the following steps: taking monomers including acrylic acid or acrylamide and dissolving them, adding initiators and crosslinking agents under the conditions of deoxygenation and continuous stirring, and reacting for a period of time under the conditions of the initiation temperature of the initiator, and drying and crushing them after the reaction is completed; the amount of the crosslinking agent added is 2.0-3.5% of the total mass of the monomer, and the crosslinking agent is a non-degradable crosslinking agent and a degradable crosslinking agent with a mass ratio of 1:3-5. In this process, in addition to acrylic acid or acrylamide, corresponding functional monomers such as sodium p-styrene sulfonate can be added to the monomers, but from the cost point of view, only acrylic acid or acrylamide can be used; for initiators, common initiators in the art can be used, such as potassium persulfate, potassium persulfate-sodium bisulfite, hydrogen peroxide, etc. The reaction time and reaction temperature can be determined according to the specific initiator. For example, when potassium persulfate is used as the initiator, the reaction temperature can be 50-60°C and the reaction time can be 2-5h, which belongs to the common sense in the art.

[0015] Since the amount of the cross-linking agent added in the present invention is relatively large, and a large amount of the cross-linking agent is a degradable cross-linking agent, the water-retaining agent finally obtained has a relatively low initial water absorption rate and a relatively slow water absorption speed. In the matrix, these water-retaining agents will degrade in about 3 to 6 months, so as to avoid these water-retaining agents not being degraded for a long time, which will cause pollution to the environment. When the water-retaining agent is degraded, the preparation on the matrix has grown up and has a certain water-retaining performance; at the same time, a large amount of plant fibers added to the matrix also begin to degrade, which will also increase the water-retaining performance of the matrix; therefore, the degradation of the water-retaining agent will not have a significant impact on the water-retaining performance of the matrix.

[0016] Furthermore, the degradable cross-linking agent is polyethylene glycol diacrylate, and the non-degradable cross-linking agent is N,N-methylenebisacrylamide.

[0017] One embodiment of the present invention is that, by weight, it includes: 1000 parts of soil, 80-150 parts of plant fiber, 45-55 parts of rice husk charcoal, 5-8 parts of walnut shells, 3-4 parts of water glass, 4-6 parts of polyvinyl alcohol, 0.02-0.05 parts of borax or boric acid, 5-15 parts of fertilizer, 1-1.5 parts of water retaining agent, and 300-500 parts of water. Under this condition, the matrix finally prepared has good performance.

[0018] Another object of the present invention is to disclose a method for preparing the above-mentioned slope greening spraying matrix, which comprises the following steps: taking polyvinyl alcohol and water glass and adding water, heating them to dissolve them, and keeping them warm at 50-80°C for 3-5 hours, then adding soil, plant fiber, rice husk charcoal, walnut shell, fertilizer, borax, and water retaining agent, stirring to mix them evenly.

[0019] The beneficial effects of the present invention are as follows: the materials used in the slope greening spraying matrix of the present invention are all environmentally friendly, such as coconut husk soil, rice husk charcoal, walnut shells, etc., which are all biological materials; water glass is an inorganic non-metallic material, which can not only play an adhesive role, but also be used as a fertilizer in the process of vegetation growth; polyvinyl alcohol itself has good natural degradation performance and will not affect the environment. At the same time, the spraying matrix of the present invention enables vegetation to have a higher germination rate, and at the same time, it can be applied to slopes with a slope of 78°; after being used in combination with grids, slope protection nets, etc., it can be applied to vertical steep slopes of up to 90°, and has a wide range of applications. DETAILED DESCRIPTION

[0020] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical scheme of the present invention is described in detail below in conjunction with embodiments, but it should not be construed as limiting the applicable scope of the present invention.

[0021] In the following examples, unless otherwise specified, the operations described are routine operations in the art.

[0022] In the following examples, unless otherwise specified, the raw materials described are conventional commercial products.

[0023] In the following examples, unless otherwise specified, the parts are by mass.

[0024] In the following examples, the water-retaining agent used is cross-linked polyacrylic acid, which is a conventional commercial product.

[0025] In the following embodiments, the preparation method of the water-retaining agent II used is as follows: 100 parts of acrylic acid, by mass, are taken, 400 parts of water are added to dissolve it, nitrogen is introduced to deoxygenate, 1.2 parts of potassium persulfate, 0.6 parts of N,N-methylenebisacrylamide, and 2.8 parts of polyethylene glycol diacrylate are added under continuous stirring, and the mixture is reacted at 55° C. for 3 hours. After the reaction is completed, it is dried, then crushed, and dried to constant weight.

[0026] Example 1

[0027] A slope greening spraying matrix comprises: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA1788, 0.04 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3h, after the end of the heat preservation, cooled to room temperature, then added with loam, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II, stirred to make them evenly mixed.

[0028] Example 2

[0029] A slope greening spraying matrix comprises: 800 parts of loam, 200 parts of sand (with a particle size of no more than 3 mm), 90 parts of coconut husk soil, 40 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA2699, 0.04 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA2699 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3 hours, after the end of the heat preservation, cooled to room temperature, then added with loam, sand, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II, stirred to make them evenly mixed.

[0030] Example 3

[0031] A slope greening spraying matrix comprises: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA1788, 0.04 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, cooled to room temperature, and then loam, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II are added, and stirred to mix evenly.

[0032] Example 4

[0033] The difference between this embodiment and embodiment 1 is that water retaining agent 2 is replaced by water retaining agent 1, and the rest are the same.

[0034] Example 5

[0035] A slope greening spraying matrix comprises: 1000 parts of loam, 180 parts of coconut husk soil, 70 parts of rice husk charcoal, 3 parts of walnut shells, 2 parts of water glass, 3 parts of polyvinyl alcohol PVA1788, 0.08 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3h, after the end of the heat preservation, cooled to room temperature, then added with loam, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II, stirred to mix evenly, and obtained the matrix.

[0036] Comparative Example 1

[0037] A slope greening spraying matrix comprises: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA1788, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3h, after the end of the heat preservation, cooled to room temperature, then added with loam, coconut husk soil, rice husk charcoal, walnut shells, compound fertilizer, and water retaining agent II, stirred to mix evenly, and obtained the matrix.

[0038] Comparative Example 2

[0039] A slope greening spraying matrix comprises: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA1788, 0.04 parts of glyoxal, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3h, after the end of the heat preservation, cooled to room temperature, then added with loam, coconut husk soil, rice husk charcoal, walnut shells, glyoxal, compound fertilizer, and water retaining agent II, stirred to mix evenly, and obtained the matrix.

[0040] Comparative Example 3

[0041] A slope greening spraying matrix includes: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 5 parts of polyvinyl alcohol PVA1788, 0.04 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 is added to water, heated to dissolve, then kept warm at 70°C for 3 hours, after the end of the heat preservation, cooled to room temperature, then added loam, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II, stirred to mix evenly, and obtained the matrix.

[0042] Comparative Example 4

[0043] A slope greening spraying matrix comprises: 1000 parts of loam, 120 parts of coconut husk soil, 50 parts of rice husk charcoal, 8 parts of walnut shells, 4 parts of water glass, 5 parts of polyvinyl alcohol PVA1788, 2 parts of borax, 12 parts of compound fertilizer, 1.3 parts of water retaining agent II, and 500 parts of water. The preparation method of the spraying matrix is ​​as follows: polyvinyl alcohol PVA1788 and water glass are added into water, heated to dissolve, then kept warm at 70°C for 3h, after the end of the heat preservation, cooled to room temperature, then added with loam, coconut husk soil, rice husk charcoal, walnut shells, borax, compound fertilizer, and water retaining agent II, stirred to make them evenly mixed.

[0044] In order to further illustrate the effect of the embodiment of the present invention, a specific method is used to test it below.

[0045] 1. Germination rate test

[0046] The slope greening spraying matrix of each embodiment 1 to 5 and comparative example 2 was placed in a culture box with a thickness of 10 cm, and the same number of plant seeds (Cynodon dactylon) were sown. Under the same intensity of light, the germination rates on the 7th and 15th days were counted. The results are shown in Table 1.

[0047] Table 1 Germination rate test table

[0048] serial number 7-day germination rate% 15 days germination rate % Example 1 92.4 94.7 Example 2 91.5 94.2 Example 3 92.9 95.6 Example 4 93.0 95.1 Example 5 93.4 94.9 Comparative Example 2 43.1 49.8 Comparative Example 4 91.8 94.2 Comparative Example 5 87.5 90.2

[0049] As can be seen from Table 1, the spraying matrix prepared in Examples 1 to 5 has a high germination rate. For Bermuda grass under natural conditions, the germination time is usually about 7 days, and the overall germination rate is between 95% and 99%. As can be seen from Table 1, the spraying matrix prepared in the embodiments of the present invention is close to the germination rate under natural conditions. Referring to Comparative Document 2, it can be seen that aldehydes can greatly inhibit the germination of Bermuda grass seeds.

[0050] 2. Slope spraying test

[0051] Take the slope greening spraying matrix of Examples 1 to 5 and Comparative Examples 1, 3 to 4, and mix them at a rate of 10 g / m 2The corresponding Bermudagrass seeds were added in a ratio of 1.5, and sprayed on the slope with an angle of 78° using a soil sprayer. The average spraying thickness was 8 cm and the total spraying area was 10 mm. 2 After spraying, the soil was maintained for 7 days, and then the vegetation coverage was calculated by digital photography at intervals. At the same time, it was observed whether the spraying matrix had fallen off. The final results are shown in Table 2. Among them, the total area of ​​vegetation coverage was calculated based on the initial total area of ​​spraying.

[0052] Table 2 Large angle consolidation test results

[0053]

[0054]

[0055] Note: In the above table, trace drop means that the total mass of the substrate dropped is no more than 2kg; small drop means that the total mass of the substrate dropped is greater than 2kg but not more than 10kg; the rest is large drop.

[0056] It can be seen from Table 2 that the slope greening spraying matrix prepared in the embodiment of the present invention can be well applied to the slope with a slope of 78°, and as time goes by, the vegetation coverage rate becomes higher and higher, indicating that the preparation can grow and breed well on the slope protection substrate.

[0057] 3. Residual water retaining agent detection

[0058] Considering that the water retaining agent has strong water absorption performance and the weight in volume will increase sharply after absorbing water, this test example adopts the following method for testing: take 1000g of the substrate after 120d in test example 2, add sufficient water and soak for 3h. After soaking, count the residual amount of water retaining agent particles after water absorption. The final results are shown in Table 3.

[0059] Table 3 Residual water retaining agent test table

[0060] serial number Residual water retaining agent weight g Example 1 2.1 Example 2 1.7 Example 3 1.3 Example 4 9.9 Example 5 1.5

[0061] As can be seen from Table 3, in Examples 1 to 3 and Example 5, the amount of residual water retaining agent is relatively low, indicating that the water retaining agent has been gradually degraded during the process and has little impact on the natural environment. In Example 4, the content of residual water retaining agent is relatively large, indicating that it is difficult to degrade and may have an impact on the natural environment.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A slope greening spraying matrix, characterized in that: Calculated by weight, it includes: 1000 parts of soil, 50-200 parts of plant fiber, 30-80 parts of rice husk charcoal, 1-10 parts of walnut shell, 1-5 parts of water glass, 2-7 parts of polyvinyl alcohol, 0.01-0.1 parts of borax or boric acid, 5-15 parts of fertilizer, 0.8-2 parts of water retaining agent, and 250-650 parts of water.

2. The slope greening spraying matrix according to claim 1, characterized in that: The plant fiber is one of coconut husk, bagasse, and fermented straw, and the lengths of the bagasse and the straw are no more than 3 cm.

3. The slope spraying matrix according to claim 1, characterized in that: The water retaining agent is polyacrylic acid gel or polyacrylamide gel.

4. The slope spraying matrix according to claim 3, characterized in that: The preparation method of the water retaining agent comprises the following steps: taking monomers including acrylic acid or acrylamide and dissolving them, adding an initiator and a crosslinking agent under the condition of deoxygenation and continuous stirring, and reacting for a period of time under the initiation temperature of the initiator, and drying and crushing the water retaining agent after the reaction is completed; the amount of the crosslinking agent added is 2.0-3.5% of the total mass of the monomers, and the crosslinking agent is a non-degradable crosslinking agent and a degradable crosslinking agent in a mass ratio of 1:3-5.

5. The slope spraying matrix according to claim 4, characterized in that: The degradable cross-linking agent is polyethylene glycol diacrylate, and the non-degradable cross-linking agent is N,N-methylenebisacrylamide.

6. The slope greening spraying matrix according to claim 1, characterized in that: Calculated by weight, it includes: 1000 parts of soil, 80-150 parts of plant fiber, 45-55 parts of rice husk charcoal, 5-8 parts of walnut shells, 3-4 parts of water glass, 4-6 parts of polyvinyl alcohol, 0.02-0.05 parts of borax or boric acid, 5-15 parts of fertilizer, 1-1.5 parts of water retaining agent, and 300-500 parts of water.

7. The method for preparing the slope greening spraying matrix according to any one of claims 1 to 6, characterized in that: The following steps are involved: Take polyvinyl alcohol and water glass and add water, heat up to dissolve them, and keep warm at 50-80°C for 3-5 hours. Then add soil, plant fiber, rice husk charcoal, walnut shell, fertilizer, borax, and water retaining agent, stir to mix evenly.

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