Vegetation substrate spraying method

Abstract

To provide an execution method which can achieve high erosion resistance and plant growth property of a sprayed growth base, in a vegetation base material spraying method.SOLUTION: In a dry type spray greening method in a vegetation base material spraying method, a vegetation base material in which water is not compounded is air pressure-fed, and apart from the vegetation base material, a suspension in which at least clay mineral and a nodulizing agent are mixed and agitated with water is pressure-fed, and the suspension is merged to the vegetation base material in the vicinity of a nozzle part and is sprayed from a nozzle tip. Thereby, a growth base is created on a slope.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a greening method for creating a growth base by spraying a vegetation base material for greening on sloping lands such as slopes. In particular, it relates to a dry spraying greening method in which an organic-based vegetation base material is pneumatically conveyed without mixing water, and water is joined to the vegetation base material near a nozzle and then sprayed.

Background Art

[0002] As greening methods for sloping lands such as slopes and landslide areas on mountainsides, three spraying greening methods, which have long been represented by seeding work, soil spraying work (also called soil and seed spraying work), and vegetation base material spraying work (also called thick layer base material spraying work), have been applied.

[0003] The vegetation base material spraying work can create a growth base with the most excellent erosion resistance among the three above-mentioned spraying greening methods, and thus is widely applied to sloping lands. Construction sites where landslides on mountainsides occur due to natural disasters or the like are often remote mountainous areas where it is difficult to approach using existing roads or the like. In such a case, when applying the vegetation base material spraying work, the vegetation base material has to be pumped over a long distance and at a high lift.

[0004] In the vegetation base material spraying work, a general wet spraying greening method in which a vegetation base material mixed with water is pneumatically conveyed and sprayed, and a dry spraying greening method in which a vegetation base material not mixed with water is pneumatically conveyed and mixed with water near a nozzle and then sprayed are known (for example, Patent Document 2). In the conventional dry spraying greening method, water is joined to a vegetation base material not mixed with water near a nozzle portion and then sprayed to create a growth base.

[0005] In vegetation substrate spraying work, in addition to wet spraying greening methods and dry spraying greening methods in which vegetation substrates are pumped under air pressure, there is also a pump-type spraying greening method in which vegetation substrates are mixed with a large amount of water to form a slurry and then pumped under pressure (for example, Patent Documents 1 and 3). Pump-type greening methods are sometimes classified as topsoil seed spraying methods. In these pump-type greening methods, a method is sometimes employed in which an aqueous solution of a granulating agent, which is made by mixing a granulating agent with water, is added to the vegetation substrate near the nozzle and then sprayed. With pump-type greening methods, by using a high-pressure concrete pump, it is possible to pump vegetation substrates to sites with long distances and high heads, which is difficult with air pressure pumping. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2000-104258 [Patent Document 2] Japanese Patent Publication No. 2004-169401 [Patent Document 3] Japanese Patent Publication No. 2007-198022 [Overview of the project] [Problems that the invention aims to solve]

[0007] The following problems exist in each of the following methods used in vegetation substrate spraying: dry spraying greening methods, wet spraying greening methods, and pump-type greening methods.

[0008] In dry spray-on greening methods that use air pressure to pump vegetation substrates without added water, the upper limit of the vertical height of the target slope is set at 80m. In particular, Patent Document 2 includes coal ash in the vegetation substrate, and Patent Document 3 includes on-site excavated soil in the vegetation substrate. Since coal ash and on-site excavated soil increase the viscosity of the vegetation substrate, long-distance, high-lift air pumping is difficult. In particular, in wet spray-on greening methods that use air pressure to pump vegetation substrates mixed with water, the spraying pressure decreases when the vertical height of the target slope exceeds the upper limit, resulting in insufficient consolidation and a soft growth base, which easily leads to insufficient erosion resistance, insufficient water retention, and germination and growth disorders. In contrast, dry spray-on greening methods are superior to wet spray-on greening methods in terms of long-distance, high-lift air pumping, but the spraying pressure inevitably decreases as the hose length increases, resulting in similar problems.

[0009] In pump-type sprayed greening methods that use a pump to deliver slurry-like vegetation substrates, the growth base, which is sprayed with a vegetation substrate that has a high water content, cannot stand on its own on slopes, making it usually impossible to create a growth base thicker than 3 cm. Furthermore, it is difficult to adjust the slump value to balance the efficiency of pump delivery with adhesion to slopes. For this reason, Patent Document 1 describes methods such as adding air near the nozzle to increase the pressure of the pumped vegetation substrate before spraying, or adding a granulating agent near the nozzle to quickly dewater after spraying. Moreover, using high pressure to pump water-containing vegetation substrates over long distances and high heads increases the cost of construction machinery and the risk to spraying workers during their work. In addition, if the vegetation substrate gradually adheres to the inside of the hose, increasing the pumping resistance, it leads to reduced workability and the creation of a growth base that is not sufficiently compacted.

[0010] In addition to vegetation substrate spraying, other greening methods include manual installation of secondary products such as vegetation sheets on slopes. However, in the case of long-distance, high-lift sites, this method presents problems of heavy workload and labor shortages. Furthermore, vegetation sheets are difficult to adhere to uneven ground, leading to erosion of the ground by rainwater. In areas prone to landslides, greening is usually required through the formation of woody plant communities that harmonize with the surrounding forest environment. However, the simple vegetation sheet method, which has poor water retention, makes it difficult to form woody plant communities quickly. Herbaceous species do not harmonize with the surrounding forest environment, resulting in delayed vegetation recovery. Moreover, due to environmental concerns related to microplastics, the use of vegetation sheets made of synthetic fibers is undesirable.

[0011] In view of the above issues, the object of the present invention is to provide a construction method for dry spraying greening in vegetation substrate spraying work that can exhibit high erosion resistance and plant growth properties in the sprayed growth substrate. [Means for solving the problem]

[0012] To achieve the above objectives, the present invention provides the following configuration. - Embodiments of the present invention are: Without mixing water into the organic vegetation substrate, the growing medium is sprayed onto the slope using compressed air at a high lift height of 80m or more over long distances. Vegetation substrate spraying work It is a law , (a) As the organic vegetation substrate, a mixture of compost and non-composted organic matter in a ratio of 8:2 to 5:5 is used. (b) For the air-pressure feeding of the organic vegetation substrate, a rotary sprayer without a pressure vessel is used, which is used to place the vegetation substrate in a pressure vessel and apply pressure to discharge the material. (c) The organic system In addition to the vegetation substrate, Bentonite And a suspension obtained by mixing and stirring the aggregate agent with water. Prepare, (d) The concentration of bentonite in the suspension is 2-5% and the concentration of the granulating agent is 0.05-0.2% by mass, (e) The aforementioned Organic The suspension is applied to the vegetation substrate. Within 1-2 meters of the nozzle They merge there, (f) After merging By spraying from the nozzle tip, it can be used on slopes. Thickness of 3 cm or more Growth base spray . - In the above embodiment, the granulating agent is a water-soluble synthetic polymer.

[0013] The inventors of the present application have found that, by spraying a suspension obtained by mixing and stirring a clay mineral and an agglomerating agent onto a vegetation base material not containing water, it is possible to improve the erosion resistance of the growth base and the plant growth ability (germination promotion effect and initial growth promotion effect) compared to the conventional dry spraying greening method, and thus completed the present invention.

Effects of the Invention

[0014] According to the dry spraying greening method of the present invention, compared with the conventional dry spraying greening method, the sprayed growth base can exhibit high erosion resistance and plant growth ability (germination promotion effect and growth promotion effect). In the method of the present invention, both the clay mineral and the agglomerating agent are contained in the sprayed growth base, but in the conventional method, a growth base containing both the clay mineral and the agglomerating agent cannot be obtained. Although the mechanism of the synergistic effect between the clay mineral and the agglomerating agent has not been elucidated, it is presumed that the erosion resistance is ensured and the germination and initial growth of plants are promoted by the form in which the clay mineral is dispersed and arranged in a form presenting an aggregate structure in the sprayed growth base. The growth base sprayed according to the present invention is particularly effective in promoting the germination and initial growth of woody plants, and can realize the early formation of a woody plant community.

[0015] When the vegetation base material is pneumatically transported over a long distance with a high lift height of 80 m or more perpendicular to the slope surface, in the conventional method, the spraying pressure decreases and the growth base becomes soft and swollen, resulting in inhibition of erosion resistance and plant growth ability. However, according to the embodiment of combining the suspension of the clay mineral or the suspension of the clay mineral and the agglomerating agent in the present invention with the vegetation base material, a great effect can also be exerted even in such a long-distance high-lift pneumatic transportation with a slope surface perpendicular height of 80 m or more. Needless to say, the present invention can also be expected to have the same effect when applied to the dry spraying greening method with a slope surface perpendicular height of 80 m or less.

Brief Description of the Drawings

[0016] [Figure 1] Figure 1 is a diagram schematically showing the construction status of the dry spraying greening method.

Modes for Carrying Out the Invention

[0017] Embodiments of the present invention will be described below with reference to the drawings illustrating examples. The slopes to which the present invention is applied include artificial slopes, natural slopes, landslide areas, and the like. Figure 1 is a schematic diagram showing the construction status of the dry sprayed greening method according to the present invention in vegetation substrate spraying work. For greening, a vegetation substrate is sprayed onto the slope 4 to create a growing base on the slope 4. The construction machinery used in the dry sprayed greening method, namely the sprayer 1, air compressor 6, and pump 7, is installed on the ground, for example, near the toe of the slope. The vegetation substrate is prepared in the sprayer 1. Mortar / concrete sprayers are widely used as the sprayer 1, but in particular, for long-distance, high-lift air-pressure delivery of the vegetation substrate, it is preferable to use a rotary-type sprayer that does not have a pressure vessel for discharging the material by placing the vegetation substrate in a pressure vessel and applying pressure. In this specification, "long-distance, high-lift" refers to the case where the vertical height h of the slope 4 to which the dry sprayed greening method is applied is 80m or more.

[0018] The spraying machine 1 is connected to an air compressor 6 on one end and to a vegetation substrate pressure delivery hose 2 on the other. The air necessary for pressurizing the vegetation substrate is supplied to the spraying machine 1 from the air compressor 6. In the case of a motor-driven spraying machine, a separate generator is required, although this is not shown in the diagram. When using air pressure to deliver the vegetation substrate in the dry spraying greening method, the vegetation substrate pressure delivery hose 2 can be made of rubber or polyvinyl chloride.

[0019] A nozzle section 3 is attached to the tip of the vegetation substrate pumping hose 2. The nozzle section 3 includes a general spray nozzle. In addition, the nozzle section 3 may have nozzle devices made of, for example, steel or rubber, or nozzle devices with special stirring mechanisms. The quality of the growing substrate created by the dry spraying greening method of the present invention is not affected by the nozzle device, so the presence or absence of these nozzle devices is optional.

[0020] Pump 7 is used to pump liquid containing water. The liquid containing water is prepared using appropriate equipment (not shown). Details of the liquid will be described later. A liquid pumping hose 5 is connected to pump 7. The tip 5a of the liquid pumping hose 5 is also connected near the nozzle 3.

[0021] The vegetation substrate, pumped by the vegetation substrate pumping hose 2, and the liquid containing water, pumped by the liquid pumping hose 5, merge near the nozzle section 3. The tip 5a of the liquid pumping hose 5 is the merging point. A merging device, such as a water ring, is attached to the merging point, or connection point, on the vegetation substrate pumping hose 2. Here, "near the nozzle section" is preferably a range of approximately 1 to 2 m including the nozzle section 3. This is because, in the dry spray greening method, the spraying worker needs to fine-tune the merging of the liquid from the liquid pumping hose 5 using a valve or the like provided at the connection point, and also mix the merged water and vegetation substrate as much as possible just before spraying.

[0022] Furthermore, in order to promote the mixing and stirring of the vegetation substrate supplied from the vegetation substrate pressure supply hose 2 and the liquid supplied from the liquid pressure supply hose 5, the nozzle section 3 may have a mixing device mechanism, or a method of merging the two at a point before the nozzle tip 3a may be employed. The structure is not particularly limited as long as it can merge the liquid with the vegetation substrate. The merged, mixed, and stirred vegetation substrate and liquid are sprayed from the nozzle tip 3a of the nozzle section 3 toward the slope 4.

[0023] The vegetation substrate fed into the spraying machine 1 contains, as a basic composition, growth substrate, erosion control material, fertilizer, and seeds. The vegetation substrate may also contain soil conditioners, etc. In another example, the vegetation substrate may not contain seeds. Normally, if these materials are fed directly into the spraying machine 1, the vegetation substrate will become uneven and the quality will not be stable, so it is preferable to mix and stir them beforehand using a shaftless mixer or the like (not shown) before feeding them into the spraying machine 1.

[0024] The growing medium can be various types of compost, including bark compost, organic materials such as peat moss, sandy soil, inorganic materials such as perlite, as well as clayey soil such as Kuroboku soil, topsoil, locally collected soil, and various recycled materials. When transporting vegetation substrates over long distances using high-pressure air, it is preferable to use only organic materials with low specific gravity and viscosity. Therefore, materials that do not contain inorganic materials, raw chips, or soil components are preferable. A mixture of compost such as bark compost and uncomposted organic materials such as peat moss or coconut shells in a ratio of 8:2 to 5:5 is preferable.

[0025] Erosion control materials can be broadly classified into synthetic resin-based (such as vinyl acetate resin) and inorganic-based (such as cement), and either type of material can be used. When transporting vegetation substrates over long distances using high-lift air pressure, inorganic erosion control materials with excellent erosion resistance are preferred. When using inorganic erosion control materials, a growing substrate with strong bonding strength can be obtained by mixing compost such as bark compost with non-composted organic matter such as peat moss or coconut shells in a ratio of 7:3 to 6:4.

[0026] In the embodiment of the present invention, the vegetation substrate contains the basic components described above. The vegetation substrate in this embodiment does not contain clay minerals, agglomerating agents, or water. On the other hand, the liquid that is introduced into the vegetation substrate near the nozzle 3 is a suspension obtained by mixing and stirring at least clay minerals and agglomerating agents with water. In the suspension, fine particles of clay minerals are dispersed in the water, and the water-soluble agglomerating agent is dissolved in the water.

[0027] In this embodiment, a suspension containing a large amount of water supplies moisture to the vegetation substrate, which is air-pressurized and has a low water content. The supply of moisture enhances the compaction effect of the sprayed vegetation substrate, suppressing rebound and enabling the spraying of a compacted growth substrate. Furthermore, the moisture supplied by the suspension also plays a role in activating the bonding and adhesive effects of the erosion control material incorporated into the vegetation substrate.

[0028] Granulation agents are chemicals that, when mixed with a liquid in which clay minerals are dispersed, cause the dispersed clay mineral particles to coagulate and form flocs (so-called clumps, aggregates). Because granulation agents are so-called flocculants, they are widely used in wastewater treatment and agriculture. The granulation agent used is not particularly limited, but a powdered polymer granulation agent (water-soluble synthetic polymer) is preferable. In this embodiment, the concentration of the granulation agent in the suspension is preferably about 0.05 to 0.2% by mass.

[0029] Clay minerals are fine particles that make up what is commonly known as clay. Examples include kaolinite, illite, montmorillonite, cronitite, serpentinite, talc, and vermiculite. In particular, bentonite, which is mainly composed of montmorillonite, is widely used in civil engineering works to ensure the stability of excavation walls, stop water flow, and improve ground bearing capacity. The clay minerals used in this invention are not particularly limited, but bentonite is preferred. In this embodiment, when the concentration of clay minerals in the suspension is approximately 2-5%, the effect of promoting germination and initial growth in the prepared growing substrate can be obtained. The concentration of clay minerals in the suspension is expressed as a percentage of the mass ratio of clay minerals to water. In particular, a concentration of clay minerals in the suspension of approximately 2% is preferred.

[0030] It is preferable to continuously stir the suspension containing dispersed clay minerals and pump it to the vicinity of the nozzle 3 to prevent material separation of the clay minerals. In particular, since the suspension in this embodiment is a mixture of clay minerals and an aggregation agent mixed and stirred with water, an agglomeration reaction will proceed, so it is preferable to maintain a state of forced stirring at all times until it is combined with the vegetation substrate near the nozzle 3. Specifically, the prepared suspension is stirred as quickly as possible using a twin-screw or pan-type forced mixer, and then quickly pumped using a high-pressure sprayer pump or plunger pump to be combined near the nozzle 3.

[0031] By applying the dry spray-on greening method of the present invention, the vegetation substrate adheres more easily to sloping ground, the sprayed growth substrate is compacted to a predetermined state, and the erosion control material mixed into the vegetation substrate hardens appropriately. As a result, the erosion resistance and plant growth properties required for spray-on vegetation substrates are achieved. Generally, the predetermined compaction for spray-on vegetation substrates that primarily use organic matter refers to a state in which the material used is compacted to half its volume by spraying. [Examples]

[0032] When using non-native grasses that germinate in a short period of 1-2 weeks to achieve early greening, it is possible to germinate and grow them even on a growing medium with low erosion resistance. However, when aiming for early forestation by primarily using woody plants (sometimes only woody plants are used) from the initial stages of construction, woody plants require at least two weeks to germinate, and some species require several months or more. Therefore, if a growing medium with low erosion resistance is created, it will be easily eroded, making it difficult for the plants to germinate and grow. For this reason, in dry-type spray-on greening methods, promoting the germination and initial growth of woody plants mixed with seeds is extremely important. The effect of promoting germination and growth in the initial stages after construction will determine whether or not the formation of woody plant communities, which is the initial greening target, is achieved. From this perspective, we conducted tests to verify the effectiveness of the dry-type spray-on greening method of the present invention.

[0033] [Early growth trials on reference morphology] (a) Preparation of clay mineral suspension Bentonite, the most commonly used clay mineral in civil engineering, was used. The concentration of the bentonite suspension is expressed as a percentage of the mass ratio of bentonite to water. Suspensions of 6-10% are used in the slurry method, and 4-12% are used in the diaphragm wall method and the cast-in-place pile method. In civil engineering, at least 2-6% is required to prevent the collapse of borehole walls by forming a mud cake using a bentonite suspension (stabilizing liquid). On the other hand, in the development of another greening method, the inventors compared the amount of bentonite effective in improving the erosion resistance of the growth substrate using products with 100, 200, and 300 mesh (sieve) and found no difference between the meshes, with an effect observed at 5-7%. Based on these findings, bentonite (200 mesh) suspensions with concentrations of 0% (water only), 1%, 2%, 5%, and 10% were prepared as clay mineral suspensions.

[0034] (b) Preparation of vegetation substrate The vegetation substrate was prepared by mixing the materials in the following proportions (see Table 6 below). • Growing substrate (Orgasoil): 2000 L / m 3 • Erosion control material (Remicontrol): 60 kg / m 3 • Slow-release fertilizer (high control): 4 kg / m 3 Vegetation substrates containing a granulation agent and vegetation substrates without a granulation agent were prepared, and when combining them, the following amounts were used. • Granulation agent (Cricoat DA-101): 1 kg / m² 3

[0035] (c) Test method Tests were conducted to confirm the effects of bentonite suspension concentrations (0%, 1%, 2%, 5%, 10%) and the presence or absence of a granulation agent in the vegetation substrate on the initial growth of plants after application. Pot tests were conducted using woody plants such as Mallotus japonicus and Indigofera tinctoria, which are frequently used in spray-applied greening methods, and the introduced herbaceous plant tall fescue. Analysis of variance was performed on tree height and plant height after 8 months. Vegetation substrates with and without a granulation agent were prepared as described in (1b) above, and the bentonite suspensions of each concentration prepared as described in (a) above were mixed into each vegetation substrate and packed into each pot.

[0036] (d) Test results Regarding bentonite concentration, no significant difference was observed between Indigofera pseudotinctoria and tall fescue, but a difference was observed with a high probability (p=0.12) in Mallotus japonicus, confirming that growth was promoted at a concentration of 2%. Furthermore, regarding the presence or absence of granulation agents, a significant difference (p<0.05) was observed in Mallotus japonicus, and a high probability difference (p=0.22) was also observed in Indigofera pseudotinctoria. As a result, it was confirmed that the combination of a 2% bentonite suspension and a soil aggregation agent can promote the initial growth of woody plants.

[0037] [Germination test on reference form] (a) Test method Based on the results of the initial growth test using the reference form described above, a pot test was conducted to further confirm the germination-promoting effect after application. This test used a vegetation substrate containing a granulation agent to examine the effect of bentonite suspension concentrations (0%, 2%, 5%) on plant germination. Analysis of variance was performed on the density of germinated plants after 2.5 months. The test method was the same as that used for the initial growth test using the reference form.

[0038] (b) Test results Regarding bentonite concentration, no difference was observed in tall fescue, but a significant difference (p<0.01) was observed in Indigofera pseudotinctoria, and a difference was observed with a high probability (p=0.23) in Mallotus japonicus. Similar to Example 1, germination was most promoted at a concentration of 2%, confirming that it not only promotes the growth of woody plants but also has the effect of promoting germination.

[0039] [Example 1] Germination and initial growth test according to this embodiment (1a) Preparation of a suspension of clay minerals and an aggregation agent A suspension containing the following clay minerals and aggregation agents, as well as water for the control group, were prepared. • Clay mineral (bentonite) concentration 2%, granulation agent (Cricoat DA-101) concentration 0.1% by mass • Clay mineral (bentonite) concentration 5%, granulation agent (Cricoat DA-101) concentration 0.1% by mass • Water supply only (for control group)

[0040] (1b) Preparation of vegetation substrate A vegetation substrate was prepared without the aggregation agent used in the initial growth test of the above reference form (see Table 6 below). It was a mixture of the woody plants Mallotus japonicus and Indigofera pseudotinctoria, and the herbaceous plant Lespedeza bicolor.

[0041] (1c) Test method In a comparative construction test, a rotary-type dry sprayer, the same type used in actual construction, was used to air-pump the vegetation substrate. Simultaneously, a liquid pump hose was used to pump in water only (control group), a suspension of 2% bentonite mixed with an aggregate agent, and a suspension of 5% bentonite mixed with an aggregate agent. These liquids were then combined with the vegetation substrate near the nozzle and sprayed onto each test group. Follow-up surveys were conducted for 2 to 5 months after construction.

[0042] (1d) Test results Table 1 shows the initial vegetation cover rate after 2 to 5 months as a result of the test. It was confirmed that the initial vegetation cover rate could be increased when a suspension of 2% bentonite suspension with an aggregation agent was used. At first glance, these differences may not seem significant, but when using woody plants for greening, there has been a problem that the initial vegetation cover rate is lower compared to greening mainly using non-native herbaceous plants. In other words, the initial growth is slow, so the area does not appear green for a long time, which is a major source of anxiety for those who commission greening work, and is often criticized as poor germination and growth after the greening work is completed. In contrast, when a suspension of 2% bentonite suspension with an aggregation agent was used, the initial vegetation cover rate was clearly improved compared to the control group and the suspension of 5% bentonite suspension with an aggregation agent. Therefore, the suspension containing clay minerals and an aggregation agent in this embodiment is effective in promoting the initial growth of woody plants and is also effective in alleviating concerns during greening work.

[0043] [Table 1]

[0044] Table 2 shows a comparison of the changes in tree height of the woody plants that were treated. Even with a suspension of 5% bentonite with an aggregate-forming agent added, a germination-promoting effect equivalent to or better than the control group was obtained. Furthermore, with a suspension of 2% bentonite with an aggregate-forming agent added, the average tree height of Mallotus japonicus and Indigofera pseudotinctoria was approximately 1.2 times higher than that of the control group after 1 to 4 months, confirming that a growth-promoting effect on woody plants was obtained.

[0045] [Table 2]

[0046] Table 3 shows the changes in the total density of Mallotus japonicus and Indigofera pseudotinctoria. In the case of a suspension of 2% bentonite suspension with an aggregation agent added, the total density was approximately 1.3 times higher compared to the control group, confirming that it has a germination-promoting effect on woody plants.

[0047] [Table 3]

[0048] [Example 2] Corrosion resistance test according to this embodiment (2a) Growing substrate used in the experiment The specimens used were those of the growth substrate sprayed during the construction process in Example 3.

[0049] (2b) Test method The erosion resistance of the growing medium 17 days after construction was assessed by comparing the amount of eroded soil using a rainfall test apparatus (DIK-600). The rainfall test was set to an hourly rainfall of 100 mm / h and a raindrop diameter of 2.5 mm. After one hour of rainfall, the amount of eroded soil was collected, and the amount of eroded soil per hour (mL / m2 / h) was determined based on the oven-dry weight of the collected soil and the bulk density of the growing medium taken from the specimen.

[0050] (2c) Test results Table 4 shows a comparison of the erosion resistance of the growth substrates. It was confirmed that a 2% bentonite suspension with an aggregate agent reduced the amount of eroded soil by 74% compared to the control group, and a 5% bentonite suspension with an aggregate agent further reduced the amount of eroded soil by 37%. In terms of erosion resistance, increasing the bentonite concentration from 2% to 5% is advantageous. However, from the results of Examples 1-3 above, the 5% bentonite suspension with an aggregate agent was inferior to the 2% bentonite suspension with an aggregate agent in terms of promoting the initial growth and germination of woody plants. Therefore, considering all factors, a 2% bentonite concentration is more effective than a 5% concentration.

[0051] [Table 4]

[0052] Table 5 shows a comparison of soil hardness in the growth substrates. When comparing the soil hardness (Yamanaka soil hardness meter) of each test plot, no significant differences were observed between the test plots. This indicates that the effects of the present invention, which improve erosion resistance and plant growth (germination promotion effect and early growth promotion effect), are not due to physical differences in the hardness of the growth substrate, but rather to the effect obtained by adding a suspension of bentonite suspension mixed with an aggregation agent near the nozzle instead of water.

[0053] [Table 5]

[0054] [Example 3] Example of material formulation Based on the above test results, Table 6 shows an example of the formulation of this embodiment as an effective material for a growth substrate in actual dry-type sprayed greening construction.

[0055] When applying the method of this embodiment, a vegetation substrate mixed with the materials listed in Table 6 is fed into a spraying machine and air-pressurized. Near the nozzle, a suspension of clay mineral (e.g., bentonite) at a concentration of 2% and a granulation agent (e.g., Cricoat DA-101) at a concentration of 0.1% by mass is added and sprayed. This creates a growing substrate that has the effect of improving the erosion resistance of the growing substrate and the plant growth (germination promotion effect and early growth promotion effect).

[0056] Note that the specifications for each component in the material formulation shown in Table 6 are not limited to those specified, and any material that can achieve a similar effect can be appropriately selected and designed. Similarly, regarding the bentonite mesh, there has been no difference in effect between 100 and 300 mesh sizes, and it is not limited to 200 mesh. In addition, the seeds can be appropriately determined in the design, and even when herbaceous plants are the main component, an improvement in erosion resistance can be obtained, but when woody plants are used, plant growth (germination promotion effect and growth promotion effect) can be improved, so the seed formulation design is more effective when woody plants are the main component. The improvement in the initial growth of woody plants will certainly make a big difference in the medium to long term greening results. In this respect, the present invention can be said to have a remarkable effect.

[0057] [Table 6] [Explanation of Symbols]

[0058] 1. Spraying machine 2. Vegetation substrate pressure hose 3. Nozzle section 3a Nozzle tip 4. Sloping land such as embankments 5. Liquid pressure transfer hose 5a tip 6. Air compressor 7 Pumps h vertical height of the slope

Claims

1. A vegetation substrate spraying method in which a growing base is sprayed onto an organic vegetation substrate without mixing it with water, by pumping air over a long distance and high lift of 80 m or more vertical height on a slope, (a) As the organic vegetation base material, a mixture of compost and non-composted organic matter in a ratio of 8:2 to 5:5 is used. (b) For the air-pressure feeding of the organic vegetation substrate, a rotary sprayer without a pressure vessel is used, which is used to place the vegetation substrate in a pressure vessel and apply pressure to discharge the material. (c) Separately from the organic vegetation substrate, a suspension is prepared by mixing and stirring bentonite and a granulating agent with water. (d) The concentration of bentonite in the suspension is 2 to 5% and the concentration of the granulating agent is 0.05 to 0.2% by mass, (e) The suspension is added to the organic vegetation substrate within a range of 1 to 2 m from the nozzle. (f) A vegetation substrate spraying method that sprays a growing base of 3 cm or more on a sloping ground by spraying from the nozzle tip after the confluence.

2. The vegetation substrate spraying method according to claim 1, wherein the granulation agent is a water-soluble synthetic polymer.

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