Artificial soil and method for producing the same

Abstract

This invention provides artificial soil that can suppress the urban heat island effect and promote greening even in urban areas, thereby contributing to the conservation, creation, and regeneration of a sustainable natural environment. [Solution] One artificial soil 700 of the present invention comprises a first layer 10a containing soil components and having a thickness that allows for planting and / or the natural growth of plants, and a second layer 20 in contact with the first layer 10a and containing charcoal or carbonized material. This artificial soil 700 includes a second layer 20 that is in direct contact with the first layer 10a, contains charcoal or carbonized material and has high water retention while being able to supply water to the first layer 10a. As a result, it becomes possible to actively take in and retain water, such as water, and thus it is possible to replenish the surrounding soil including the planting layer with water and suppress the occurrence of the heat island phenomenon by utilizing the latent heat from transpiration from planted plants, thereby contributing to the conservation, creation and regeneration of a sustainable natural or living environment.

Description

Technical Field

[0001] The present invention relates to artificial soil and a method for manufacturing the same.

Background Art

[0002] In recent years, environmental problems such as global warming and the heat island phenomenon have become serious. Global warming is caused by the greenhouse effect due to the increase in the concentration of carbon dioxide in the atmosphere, resulting in the absorption of solar heat on a global scale exceeding the amount of heat released from the earth to the universe. On the other hand, the heat island phenomenon is a phenomenon in which waste heat derived from solar radiation and energy consumption is stored and heated due to the reduction of the water retention capacity of soil due to the expansion of artificial covering areas due to urbanization. In particular, in urban areas, the above problems are closely related to the aforementioned environmental problems and social issues related to the conservation, creation, and regeneration of green spaces.

[0003] From the viewpoints of conservation, creation, and regeneration of green spaces, a plurality of prior arts have been disclosed for realizing soil suitable for planting even in urban areas. For example, a waterproof sheet is laid on the roof or rooftop of a building, and the waterproofing effect of the waterproof sheet suppresses damage such as weathering and water leakage of the building. Soil is disposed on the waterproof sheet to grow plant seeds, and heat from a concrete roof or the like exposed to direct sunlight is reduced to reduce ceiling burning, and a greening method capable of suppressing the occurrence of the heat island phenomenon as much as possible has been disclosed (Patent Document 1).

[0004] Also, it has an upper layer including the ground surface and a lower layer disposed below the upper layer, and the upper layer and the lower layer have an overlapping portion. The lower layer includes a plurality of first formed bodies containing soil constituent materials, carbon, and a binder. The first formed body contains carbon in a volume ratio of 50% or more and 95% or less, and a binder in a volume ratio of 5% or more and 50% or less. The first formed body has a size of 30 mm 3 or more and 60 mm 3 or less. The saturated permeability coefficient of the lower layer is larger than that of the upper layer, and the saturated permeability coefficient of the lower layer is 1.0×10 -5A planting ground is disclosed in which the density is m / s or greater, and in the lower layer, the multiple first molded bodies make up 10% to 90% of the volume of the mixture of soil constituent materials and multiple first molded bodies (Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-204554 [Patent Document 2] Japanese Patent Publication No. 2024-075101 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention can contribute to the construction of artificial soil that can realize at least one selected from the group of functions that enable, for example, infiltration and / or storage to allow rainwater recharge, utilization of latent heat through vaporization, and storage of soil carbon. Furthermore, the present invention can contribute to the suppression of the urban heat island phenomenon, the suppression of heavy rain disasters through water storage by greening, and concrete measures to prevent global warming through carbon sequestration, thereby greatly contributing to the conservation, creation, and regeneration of a sustainable natural and living environment.

[0007] In natural vegetation succession, bare ground tends to be hotter because, like cities with low green coverage, it generates less latent heat through evapotranspiration. On the other hand, forests increase latent heat through evapotranspiration while decreasing sensible heat, resulting in a comfortable temperature environment for humans, for example, and also stimulating atmospheric water circulation. Therefore, the inventors considered that introducing heat transport via atmospheric water circulation, such as rainwater, into urban environments is a realistic solution to the urban heat island effect, both economically and physically. In addition, the inventors considered that actively increasing the water retention capacity of soil, regardless of whether it is an urban area or not, can contribute to the realization of soils and planting environments that are resilient to climate change, such as global warming.

[0008] However, the inventors determined that it would be difficult to reliably achieve the preservation, creation, and regeneration of green spaces (especially in urban areas) without not only increasing the water retention capacity of the soil, but also replenishing the entire area in which the soil is located with moisture, such as rainwater. This is because unless measures are taken to increase the water retention capacity of the soil and prevent it from reaching its limit, it will not lead to a solution to the social problem of dealing with heavy rains, such as the so-called "guerrilla downpours" and "linear rainbands" that have become frequent in recent years.

[0009] From the perspective of solving at least some of the above technical problems, the inventors have determined that even if the conventional technologies described above are adopted, the above problems cannot be solved. Specifically, if the technology of Patent Document 1 is adopted, the water-blocking effect of the waterproof sheet can contribute to improving water retention by utilizing a charcoal layer, etc., but for example, when the amount of rain that flows in exceeds its water retention capacity, the water-blocking effect of the waterproof sheet will instead greatly limit the drainage capacity of the soil, in other words, the water supply capacity to soil other than that soil. Furthermore, if the technology of Patent Document 2 is adopted, the upper layer is a "water retention layer" that can be planted, and the lower layer is a "drainage layer", so the stored rainwater cannot be replenished to the surrounding soil. In addition, since the upper layer functions as a "water retention layer" that can be planted, a drainage function is required to prevent or suppress root rot of plants and to ensure respiration of the root zone of the plants.

[0010] Based on the above considerations and analyses, the inventors have diligently conducted research and have found that the above-mentioned problems can be solved by arranging or providing the following two interrelated soils (1) and (2), each playing a different role. As a result, the inventors have learned that it is possible to suppress the occurrence of the heat island phenomenon and, even in urban areas, contribute to the preservation, creation, and regeneration of a sustainable natural and living environment by promoting measures against heavy rainfall through the replenishment of moisture represented by rainwater and heat transfer through the utilization of latent heat. (1) The first layer (soil) which is thick enough for planting and is primarily used for planting or serves as soil in which plants grow naturally. (2) A second layer (soil) that is in direct contact with the first layer in (1) above and is responsible for both "water retention" and "water supply". More specifically, the second layer (soil) is in direct contact with the first layer, maintaining a state where moisture can freely move, while actively incorporating charcoal and / or carbonized materials to exhibit high water retention capacity, and is also capable of supplying moisture to the first layer (in other words, exhibiting the ability to penetrate / move into the first layer).

[0011] Furthermore, the inventors have found that, in addition to the above-mentioned findings, the above-mentioned problems can be solved with greater certainty by implementing the improvements described in (3) below. (3) The first layer of (1) above is formed such that it has a surface (second surface) that is in the thickness direction of the first layer or inclined toward the thickness direction from the surface (first surface) that is different from the surface (first surface) of the first layer of (1) above that is the surface (first surface) of the planting target and / or the surface (first surface) of the plant that will grow naturally, and that is in contact with the outside air (in other words, is exposed to the outside air or can take in air (especially oxygen) from the outside air).

[0012] Furthermore, in addition to the findings described above, the inventors believe that by actively mixing or incorporating the charcoal and / or carbonized materials used to improve water retention and water supply into the second layer (soil), it may be possible to contribute to the realization of a decarbonized society through so-called "carbon sequestration" using soil.

[0013] Specifically, taking biochar as an example, at the 2019 IPCC General Assembly, the application of biochar to soil was recognized as a method of carbon sequestration. Therefore, if biochar is used in the aforementioned charcoal and / or carbonized materials, it could be recognized internationally as a social implementation of "carbon sequestration."

[0014] Furthermore, even after energy conservation or renewable energy is introduced to reduce carbon dioxide emissions, any remaining carbon dioxide emissions that cannot be reduced must be addressed by absorbing or storing the carbon dioxide. Therefore, based on the above-mentioned knowledge, the inventors believe that utilizing charcoal and / or carbonized materials (typically biochar) can stably store carbon derived from atmospheric carbon dioxide, thereby contributing as a promising concrete method toward achieving negative emissions through "carbon removal activities," and ultimately toward growth-type carbon pricing through Green Transformation (GX), a Japanese policy aimed at achieving both emission reduction and economic growth, towards achieving "carbon neutrality" by 2050.

[0015] This invention was created based on the above-mentioned knowledge and ingenuity. [Means for solving the problem]

[0016] One artificial soil of the present invention comprises a first layer having a thickness suitable for planting and / or for plants to grow naturally, and a second layer in contact with the first layer and containing charcoal and / or carbonized material.

[0017] This artificial soil has a second layer that is in direct contact with or adjacent to the first layer described above, and contains charcoal and / or carbonized material, providing high water retention while supplying moisture to the first layer. As a result, due to the technical effects shown in (a) and (b) below, even in urban areas, it can contribute to countermeasures against heavy rainfall through the replenishment of moisture represented by rainwater, and to the suppression of the heat island phenomenon by promoting heat transfer through the utilization of latent heat, as well as to the preservation, creation, and regeneration of a sustainable natural and living environment. (a) Because the second layer, which may have high water retention capacity, is in direct contact with or adjacent to the first layer, moisture held in the second layer can be supplied to the first layer (in other words, it can penetrate / move into the first layer). (b) Trees, grasses, flowers and / or mosses planted in the first layer (hereinafter collectively referred to as "plants") may benefit from the moisture supplied (discharged) from the second layer.

[0018] In the above invention of artificial soil, it is a preferred embodiment that the above-mentioned first layer is in a state where it can be in contact with the outside air or exposed to the outside air (hereinafter, also collectively referred to as "capable of being in contact with the outside air"), and has a second surface shown in the following (x) or (y). This is because by providing the second surface, the artificial soil can enjoy the air supplied from the second surface of the first layer, which is less affected by the second layer having high water retention, or can prevent or suppress the entire rhizosphere of the plant from being in a waterlogged condition. (x) A second surface in the thickness direction of the first layer, which is different from the first surface for planting or for the natural growth of plants. (y) A second surface inclined from the first surface toward the thickness direction side, which is different from the first surface for planting or for the natural growth of plants.

[0019] Another artificial soil of the present invention includes a first layer having a thickness capable of planting and / or allowing plants to grow naturally, which contains a soil structure material, and a second layer that is in contact with the first layer and contains carbon and / or carbide. In addition, in this artificial soil, the above-mentioned first layer has a second surface that is different from the first surface for planting or for the natural growth of plants, is capable of being in contact with the outside air, is in the thickness direction, or is inclined from the first surface toward the thickness direction side.

[0020] According to this artificial soil, it is provided with a second layer that is in direct contact with the above-mentioned first layer, contains carbon and / or carbide, has high water retention, and can supply moisture to the first layer. In addition, according to this artificial soil, it has a surface (second surface) that is different from the first surface for planting or for the natural growth of plants in the above-mentioned first layer, is capable of being in contact with the outside air (in other words, can take in air from the outside air or does not become a waterlogged condition), is in the thickness direction of the first layer, or is inclined from the first surface toward the thickness direction side. As a result, due to the technical effects shown in the following (a) to (c), it can suppress the occurrence of the heat island phenomenon, and even in an urban area, it can contribute to the preservation, creation, and regeneration of a sustainable natural or living environment by taking measures against heavy rain through the retention of moisture represented by rainwater and promoting heat transfer by using latent heat. (a) Since the second layer that can have high water retention is in direct contact with the first layer, the water retained in the second layer can be supplied to the first layer (in other words, it can penetrate / move into the first layer). (b) Trees, lawns, flowers and / or mosses, etc. (hereinafter also collectively referred to as "plants") planted in the first layer can enjoy the water supplied (discharged) from the second layer. (c) It can enjoy the air supplied from the second side of the first layer where the influence of the second layer with high water retention is small, or it can prevent or suppress the entire rhizosphere of the plant from being in a waterlogging condition.

[0021] One method for manufacturing an artificial soil of the present invention includes an arranging step of arranging a second layer containing carbon and / or carbide so as to be in contact with a first layer having a thickness capable of planting and / or allowing plants to grow spontaneously, the first layer including a soil structure material.

[0022] According to this method for manufacturing an artificial soil, it is possible to form an artificial soil provided with a second layer that contains carbon and / or carbide, has high water retention, and can supply water to the first layer while being in direct contact with the above-mentioned first layer. In a preferred embodiment of implementing the invention of this method for manufacturing an artificial soil, for example, by performing an arranging step of arranging the above-mentioned second layer so as to be in contact with an existing first layer having a thickness capable of planting and including a soil structure material, the artificial soil can be formed. From the foregoing viewpoints, it is particularly noteworthy that an existing soil can be relatively easily and / or relatively inexpensively recreated into the artificial soil.

[0023] In addition, according to the artificial soil formed by the above-mentioned manufacturing method, it is provided with a second layer that contains carbon and / or carbide, has high water retention, and can supply water to the first layer while being in direct contact with the above-mentioned first layer. As a result, due to the technical effects shown in the following (a) and (b), it is possible to suppress the occurrence of the heat island phenomenon, and even in an urban area, it can contribute to the preservation, creation and regeneration of a sustainable natural or living environment by promoting heat transfer by latent heat utilization and flood countermeasures through the conservation of moisture represented by rainwater, thereby forming the artificial soil. (a) Because the second layer, which may have high water retention capacity, is in direct contact with the first layer, moisture held in the second layer can be supplied to the first layer (in other words, it can penetrate / move into the first layer). (b) Trees, grasses, flowers and / or mosses planted in the first layer can benefit from the moisture supplied (discharged) from the second layer, or the entire root zone of the plants is less likely to be waterlogged.

[0024] Furthermore, in the invention of the method for manufacturing artificial soil described above, it is a preferred embodiment that the first layer described above is in a state that allows it to come into contact with the outside air and has a second surface as shown in (x) or (y) below. This is because, by providing the second surface, the artificial soil can enjoy the air supplied from the second surface of the first layer, which is less affected by the second layer that can have high water retention, or it is possible to prevent or suppress the entire root zone of the plant from becoming waterlogged. (x) A second surface in the thickness direction of the first layer that is different from the first surface of the planting target and / or the natural habitat of the plant. (y) A second surface that is different from the first surface on which the planting and / or the natural habitat of the plants is located, and is inclined toward the thickness direction from the first surface.

[0025] Furthermore, another method for producing artificial soil according to the present invention includes a placement step of placing a second layer containing charcoal and / or carbonized material in contact with a first layer containing soil components and having a thickness on which plants can be planted and / or on which plants can grow naturally. In addition, in this method for producing artificial soil, the aforementioned first layer has a second surface that is different from the first surface on which plants are to be planted and / or on which plants can grow naturally, and is in contact with the outside air, either in the thickness direction or inclined toward the thickness direction from the first surface.

[0026] According to this method for producing artificial soil, it is possible to form artificial soil that includes a second layer containing charcoal and / or carbonized material, which has high water retention properties and can supply moisture to the first layer, and is in direct contact with the first layer. In a preferred embodiment of this invention for producing artificial soil, for example, the artificial soil can be formed by performing a placement step in which the second layer is subsequently placed in contact with an existing first layer containing soil components and having a planting thickness. From the above-mentioned viewpoint, it is noteworthy that existing soil can be transformed into artificial soil relatively easily and / or relatively inexpensively.

[0027] In addition, the artificial soil formed by the above-described manufacturing method has a surface (second surface) that is different from the first surface of the first layer that is the target of planting and / or the target of natural plant growth, which is in contact with the outside air (in other words, it can take in air from the outside air, or the entire root zone of the plant is less likely to be subjected to waterlogging conditions), which is in the thickness direction of the first layer, or is inclined toward the thickness direction from the first surface. As a result, through the technical effects shown in (a) to (c) below, it is possible to form an artificial soil that can suppress the occurrence of the heat island phenomenon and, even in urban areas, promote measures against heavy rainfall through the replenishment of water represented by rainwater and promote heat transfer through the utilization of latent heat, thereby contributing to the conservation, creation, and regeneration of a sustainable natural or living environment. (a) Because the second layer, which may have high water retention capacity, is in direct contact with the first layer, moisture held in the second layer can be supplied to the first layer (in other words, it can penetrate / move into the first layer). (b) Trees, grasses, flowers and / or mosses planted in the first layer can benefit from the moisture supplied (discharged) from the second layer, or the entire root zone of the plants is less likely to be waterlogged. (c) It can enjoy air supplied from the second surface (the second surface in the first layer) which is less affected by the second layer which may have high water retention.

[0028] Furthermore, in each of the above-described inventions, the "surface of the planting target and / or the plant's natural habitat" of the "first layer having a thickness on which plants can be planted and / or on which plants can grow naturally" is not limited to one surface. For example, the first layer may have multiple surfaces of the "surface of the planting target and / or the plant's natural habitat." Also, the "surface of the planting target and / or the plant's natural habitat" is not limited to the first surface of the first layer. For example, it is another possible embodiment in each of the above-described inventions that the surface of the planting target and / or the plant's natural habitat is a second surface in addition to the first surface.

[0029] Furthermore, in each of the above-described inventions, the "surface of the planting target and / or plant habitat" of the "first layer having a thickness on which plants can be planted and / or on which plants can grow naturally" is not limited to the surface on which plants are newly planted (or are planned to be planted) and / or the surface on which plants are newly planted (or are planned to be planted). For example, it may include cases where existing planted and / or already growing plants exist on at least a part of the "surface of the planting target and / or plant habitat" of the first layer. Also, the first surface of the "surface of the planting target and / or plant habitat" is not limited to the surface on which plants are newly planted (or are planned to be planted) and / or the surface on which plants are newly planted (or are planned to be planted). For example, the first surface of the "surface of the planting target and / or plant habitat" may include cases where existing planted and / or already growing plants exist on at least a part of that surface.

[0030] Furthermore, the "thickness direction" of the "first layer" in this application is not necessarily limited to a vertically downward direction. For example, in cases where plants are planted on the wall surface of a building (typically, so-called "vertical greening"), a surface that is substantially parallel to the wall surface (at least a surface that is not substantially perpendicular to the wall surface) may correspond to the first surface of the first layer of the present invention, which is one possible embodiment. [Effects of the Invention]

[0031] One artificial soil of the present invention can suppress the occurrence of the urban heat island effect and promote heat transfer through the replenishment of water, such as rainwater, and the utilization of latent heat, even in urban areas, thereby contributing to the preservation, creation, and regeneration of a sustainable natural and living environment. Furthermore, one artificial soil of the present invention can also contribute to so-called carbon sequestration.

[0032] Furthermore, according to one method for producing artificial soil of the present invention, it is possible to create artificial soil that can suppress the occurrence of the heat island phenomenon and contribute to the preservation, creation, and regeneration of a sustainable natural or living environment by promoting measures against heavy rainfall through the replenishment of water represented by rainwater and heat transfer through the utilization of latent heat, even in urban areas. Moreover, according to this method for producing artificial soil, for example, existing soil can be transformed relatively easily and / or relatively inexpensively into artificial soil that can suppress the occurrence of the heat island phenomenon and contribute to the preservation, creation, and regeneration of a sustainable natural or living environment by promoting greening even in urban areas. [Brief explanation of the drawing]

[0033] [Figure 1] This figure shows the general configuration of the artificial soil 100 in the first embodiment. [Figure 2] This figure shows part of the manufacturing process of artificial soil 100 in the first embodiment. [Figure 3] This figure shows part of the manufacturing process of artificial soil 100 in the first embodiment. [Figure 4] This figure shows part of the manufacturing process of artificial soil 100 in the first embodiment. [Figure 5] These are photographs and a schematic diagram illustrating a portion of the comparative experiment in the first embodiment. [Figure 6] This figure shows the general configuration of the artificial soil 200 in the second embodiment. [Figure 7] This figure shows the general configuration of the artificial soil 300 in the third embodiment. [Figure 8]This figure shows the schematic configuration of another artificial soil 400 in the third embodiment. [Figure 9] This figure shows the general configuration of the artificial soil 500 in a modified example (1) of the second embodiment. [Figure 10] This figure shows the general configuration of the artificial soil 600 in a modified example (2) of the second embodiment. [Figure 11] This figure shows the general configuration of the artificial soil 200a in a modified example (3) of the second embodiment. [Figure 12] This figure shows the general configuration of the artificial soil 700 in the fourth embodiment. [Figure 13] This figure shows the general configuration of the artificial soil 700a in the modified example (1) of the fourth embodiment. [Figure 14] This figure shows the general configuration of the artificial soil 700b in a modified example (2) of the fourth embodiment. [Figure 15] This figure shows the general configuration of the artificial soil 800 in the fifth embodiment. [Figure 16] This figure shows the general configuration of the artificial soil 800' in a modified example (1) of the fifth embodiment. [Figure 17] This figure shows the general configuration of the artificial soil 750 in the modified example (3) of the fourth embodiment. [Figure 18] This figure shows the general configuration of the artificial soil 750' in the modified example (4) of the fourth embodiment. [Figure 19] This figure shows the general configuration of the artificial soil 850 in the modified example (2) of the fifth embodiment. [Figure 20] This figure shows the general configuration of the artificial soil 900 in the modified example (5) of the fourth embodiment. [Figure 21] This figure shows the general configuration of the artificial soil 950 in the modified example (3) of the fifth embodiment. [Figure 22] This figure shows the general configuration of the artificial soil 250 in a modified example (4) of the second embodiment. [Figure 23]This figure shows the general configuration of the artificial soil 250' in a modified example (5) of the second embodiment. [Figure 24] This figure shows the general configuration of the artificial soil 150 in a modified example (2) of the first embodiment. [Figure 25] This figure shows the general configuration of the artificial soil 260 in a modified example (6) of the second embodiment. [Figure 26] This figure shows the general configuration of the artificial soil 160 in a modified example (3) of the first embodiment. [Modes for carrying out the invention]

[0034] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this description, unless otherwise specified, common parts are denoted by common reference numerals throughout the drawings. Furthermore, the elements of this embodiment are not necessarily shown in their dimensions in the drawings. Also, some reference numerals may be omitted to improve the clarity of the drawings.

[0035] <First Embodiment> [Overview of Artificial Soil 100] Figure 1 shows the general configuration of the artificial soil 100 in this embodiment. Figures 2 to 4 show a part of the manufacturing process of the artificial soil 100 in this embodiment.

[0036] As shown in Figure 1, the artificial soil 100 of this embodiment comprises a first layer 10 having a thickness suitable for planting and / or a thickness suitable for plants to grow naturally, a second layer 20 adjacent to the first layer 10, and a third layer 40 provided above the second layer 20.

[0037] More specifically, in this embodiment, the first layer 10 contains soil components and has a thickness that allows for the planting of plants such as flowers (P in Figure 1) or trees (T in Figure 1), and / or allows plants to grow naturally. The second layer 20 contains charcoal and / or carbonized material and is arranged in contact with the first layer 10. The third layer 40 is arranged above the second layer 20 and is permeable to water. In addition, the second layer 20 and the third layer 40 in this embodiment are in contact with the surface of the first layer 10 along the thickness direction. The third layer 40 may also be formed by combining bricks or the like, as long as it is permeable to water.

[0038] In addition, in the artificial soil 100, the first layer 10 has a second surface 14 in the thickness direction of the first layer 10 that is different from the first surface 12 on which the planting target and / or the natural growth target of the plants is, and is in contact with the outside air (as already explained, this includes the meaning of "exposed to the outside air"). Furthermore, the third layer 40 does not cover the entirety of the second surface 14 of the first layer 10. In other words, even if the third layer 40 is placed, the second surface 14 of the first layer 10 in this embodiment remains in a state where it is in contact with the outside air.

[0039] Therefore, in the first layer 10 of the artificial soil 100 of this embodiment, a state is maintained in which air can be taken in from at least the second surface 14, or the entire root zone of the plant is less likely to become waterlogged. As a result, plants such as wildflowers (P in Figure 1) or trees (T in Figure 1) planted in or growing naturally in the first layer 10 can enjoy the air supplied from the second surface 14 (the second surface 14 in the first layer 10), which is less or almost unaffected by the second layer 20, which has high water retention. This makes it less likely for the entire root zone of the plant to become waterlogged, thus preventing root rot in the plant with a high degree of certainty and making planting possible.

[0040] Here, the "soil components" that the first layer 10 in this embodiment may contain are not particularly limited as long as they are materials on which flowers or trees can grow. Typical examples of soil components include crushed stone, crushed rock, clinker ash, sand, compost, coal ash, minerals, wood chips, rice hulls, bark, peat, coconut shells, coconut husks, fertilizer (which may contain carbonized material), natural soil, or a mixture of two or more of the materials listed above.

[0041] Furthermore, in this embodiment, since the second layer 20 plays the role of a water-retaining layer, the "charcoal" that the second layer 20 may contain is not particularly limited as long as it can retain moisture to the extent that the effects of this embodiment can be achieved. Typical examples of "charcoal" include powdered charcoal, bamboo charcoal, black charcoal, white charcoal, sawdust charcoal, crushed wood charcoal, or a mixture of two or more of the materials listed above. Typical examples of "carbonized materials" include biochar (made from pruned branches, thinned wood, charcoal derived from gasification wood biomass power generation, waste wood, food residue, livestock excrement, rice husks, rice, straw, nut shells, sewage sludge, paper sludge, industrial waste, and / or general waste). Examples of materials other than the aforementioned "charcoal" and / or "carbonized materials" that may constitute the second layer 20 are soil components that the first layer 10 may contain. Therefore, the second layer 20 may be a mixture of the "soil component" and the "charcoal" and / or the "carbonized material," or it may be only the "charcoal" or only the "carbonized material." Furthermore, it is a preferred embodiment for the second layer 20 to contain inorganic materials that do not decompose in the soil in addition to the "charcoal" and / or the "carbonized material." Typical examples of "inorganic materials" include concrete, volcanic rocks such as pumice, porous ceramics, diatomaceous earth, zeolite, and other porous materials. In addition, if the "charcoal" that the second layer 20 may contain is biochar, and the biochar is "pulverized charcoal," it is a preferred embodiment to provide a permeable support structure (such as a plastic plate-like body with through holes for water permeability and appropriate rigidity) between the second layer 20 and the third layer 40, or on the upper surface of the second layer. This is because the second layer 20 is more likely to become gel-like when it absorbs moisture, thus reducing the possibility that when passersby step onto the second layer 20, the second layer 20 will sink in, causing them to lose their balance or get injured.

[0042] In addition, unlike the first layer 10, the second layer 20 of this embodiment is not intended to be a layer on which plants can be planted or grow naturally. Therefore, it is possible to actively increase the content ratio of "charcoal" and / or "carbonized material" in the constituent materials of the second layer 20. Accordingly, the content ratio (volume %) of "charcoal" and / or "carbonized material" that the second layer 20 may contain is greater than 10% and less than or equal to 100%. As a result, the second layer 20 can function as a water-retaining layer. Furthermore, as described above, since the second layer 20 is arranged in direct contact with the first layer 10, the second layer 20 can also function as a moderate water supply source, supplying water from the second layer 20 to the first layer 10 via the boundary 30 between the second layer 20 and the first layer 10. Examples of constituent materials other than "charcoal" and / or "carbonized material" in the second layer 20 are the same as the "soil constituent materials" that the first layer 10 may contain. Furthermore, from the viewpoint of further enhancing the water retention of the second layer 20, the preferred content ratio (volume %) of "charcoal" and / or "carbonized material" that the second layer 20 may contain is greater than 20% and 100% or less. Also, in the case of the second layer 20 where planting is not actively envisioned, the preferred content ratio (volume %) of "charcoal" and / or "carbonized material" focusing solely on water retention is 30% or more and 100% or less (more preferably 40% or more and 100% or less). Furthermore, from the viewpoint of implementing carbon sequestration, one preferred embodiment is that the aforementioned "charcoal" and / or "carbonized material" is biochar, and the content ratio (volume %) of "biochar" in the second layer 20 is 50% or more (preferably 70% or more) and 100% or less.

[0043] As described above, the artificial soil 100 of this embodiment includes a water-retentive second layer 20 arranged in contact with the first layer 10. By configuring the second layer 20 to be in direct contact with the first layer 10, the water-retentive second layer 20 can supply water to the first layer 10 while maintaining a state in which water can freely move between the second layer 20 and the first layer 10. In other words, the ability of water to penetrate / move from the second layer 20 to the first layer 10 can be exercised.

[0044] As a result, if there are plants planted and / or naturally growing in the first layer 10, these plants can enjoy the water supplied (discharged) from the second layer 20 through the first layer 10. This makes it possible to reduce, for example, the number of times or the amount of water required to maintain the plants in the first layer 10 within a certain period, thereby significantly reducing the burden of plant maintenance. This reduction in the burden of plant maintenance can greatly contribute to promoting greening and the conservation, creation, and regeneration of sustainable natural and living environments. Furthermore, because the burden of plant maintenance can be reduced, the use of the artificial soil 100 of this embodiment when planting various plants in public places (e.g., parks, green spaces, etc.) is a suitable embodiment from the viewpoint of promoting the effective use of tax money.

[0045] As described above, the artificial soil 100, which is arranged in contact with the first layer 10 and has a second layer 20 with water retention properties, can promote greening even in urban areas and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment. Furthermore, for example, the growth of multiple large trees in an urban area can contribute to the formation of a localized environment similar to a forest, such as the creation of shade by these trees and temperature regulation through transpiration.

[0046] Furthermore, the material constituting the third layer 40 in this embodiment is not particularly limited, as long as it is a material that can exhibit water permeability that allows water supplied by rainwater or irrigation to reach the second layer 20. Typical examples of materials constituting the third layer 40 are one or more materials selected from the group consisting of natural stone (such as Shirakawa sand, Kanmizuishi sand, and Shiratamaishi soil), volcanic rocks such as pumice and scoria, granular or crushed ceramics such as pottery, bricks, and tiles, porous materials such as diatomaceous earth and zeolite, and wood used for covering (such as coconut shell chips). One preferred embodiment is to use the material constituting the third layer 40 to promote the evaporation of moisture that may be contained in the second layer 20 and / or the third layer 40 by utilizing capillary action. In addition, providing a sandbar-like design on the surface of the third layer 40 is also preferable from the viewpoint of forming an appearance that appeals to human vision. Furthermore, it is desirable from the standpoint of increasing urban land use rates for the third layer 40 to have the above-mentioned functions while utilizing a portion of its surface as a road surface such as asphalt.

[0047] Furthermore, it is a preferred embodiment for the third layer 40 to have water retention properties in addition to the water permeability described above. Another preferred embodiment is that the third layer 40 has even greater water retention properties, as this helps to achieve a water retention capacity exceeding that of the second layer 20, and thus helps to retain moisture for a longer period of time. In addition, because the material constituting the third layer 40 has a large surface area and good permeability, a large amount of water evaporates from the soil surface, so that heat transfer using latent heat can be realized more efficiently. From each of the above viewpoints, an example of a material constituting a preferred third layer 40 that has water permeability and water retention properties, as well as high permeability that increases the amount of water evaporation, is porous soil (granular porous soil material) represented by Hyuga soil.

[0048] Furthermore, by positioning the third layer 40 such that its surface is lower than the surface of the first layer 10, for example, the rainwater absorption capacity of the artificial soil 100 can be improved by utilizing the water retention capacity of the third layer 40 itself and / or the second layer 20 located below the third layer 40. As a result, the artificial soil 100 of this embodiment can mitigate the effects of heavy rain, such as so-called "guerrilla downpours" and "linear rainbands." Moreover, because the second layer 20 containing "charcoal" and / or "carbonized material" has higher water retention capacity than ordinary soil, the amount of heat from vaporization (latent heat) when the water retained by the second layer 20 evaporates increases, and the time until vaporization can be extended relative to the amount of water retained. As a result, the artificial soil 100 of this embodiment can suppress the occurrence of the heat island phenomenon. Furthermore, the fact that the third layer 40 has higher water retention than ordinary soil is a preferred embodiment because, in addition to the second layer 20, the third layer 40 can more reliably contribute to mitigating the effects of heavy rain and / or suppressing the occurrence of the heat island phenomenon. Also, as described above, since the artificial soil 100 of this embodiment includes the second layer 20, it can also contribute to so-called carbon sequestration.

[0049] Here, the thickness of the first layer 10 in the artificial soil 100 of this embodiment is not particularly limited as long as it is thick enough for planting and / or for plants to grow naturally. It can be appropriately selected depending on the type of plant to be planted. For example, the thickness of the first layer 10 intended for planting only herbaceous plants may be thinner than the thickness of the first layer 10 intended for planting trees. A typical thickness of the first layer 10 intended for planting only herbaceous plants is about 200 mm to about 400 mm (more narrowly, about 200 mm to about 350 mm), and the thickness of the first layer 10 intended for planting trees is about 500 mm or more (more narrowly, about 600 mm or more).

[0050] Furthermore, the thickness of the second layer 20 in the artificial soil 100 of this embodiment is not limited as long as it can function as a water-retaining layer, but a typical thickness of the second layer 20 is 100 mm or more (preferably 300 mm or more, more preferably 500 mm or more, even more preferably 700 mm or more, even more preferably 1000 mm or more) and approximately 5000 mm or less (preferably 3000 mm or less, even more preferably 2000 mm or less). If the thickness of the second layer 20 is less than 100 mm, the amount of water that the second layer is required to retain in this embodiment decreases, and as a result, the ability to supply (discharge) water from the second layer 20 to the first layer 10 side decreases. Therefore, from the above viewpoint, the thicker the second layer 20, the greater the amount of water retained and / or the water supply capacity to the first layer 10. On the other hand, there is no particular upper limit to the thickness of the second layer 20, but from the viewpoint of the effectiveness of civil engineering work to form the second layer 20, it is preferable that the thickness of the second layer 20 be approximately 5000 mm or less. For example, when forming the second layer 20 using a small excavator used in landscaping work, it is a suitable embodiment to make the thickness of the second layer 20 2000 mm or less, considering the feasibility of construction. Another suitable embodiment is to use a non-penetrating hole formed by removing an existing structure as the second layer 20. In addition, the thickness of the third layer 40 in the artificial soil 100 of this embodiment is not limited as long as water permeability is not hindered, but a typical thickness of the third layer 40 is approximately 100 mm to approximately 300 mm.

[0051] [Method for producing artificial soil 100] Figures 2 to 4 show a part of the manufacturing process of the artificial soil 100 in this embodiment.

[0052] As shown in Figures 2 and 3, first, a portion of the existing soil 90, which includes soil components that are suitable for planting and / or where plants naturally grow, is removed to create a space 70 that allows for the placement of the second layer 20, which will be described later. In Figure 2, a state in which plants naturally grow in a portion of the existing soil 90 is shown, but if the existing soil 90 is suitable for planting, it is not necessary for plants to already be naturally growing when removing a portion of the soil.

[0053] Subsequently, as shown in Figure 4, a first arrangement step is performed in which water-retentive materials, consisting only of charcoal, only of carbonized material, or a material containing said charcoal and / or carbonized material (for example, a mixture of "soil components" and "charcoal" as described above), which constitute the second layer 20, are placed in the space 70 formed by removing a portion of the existing soil 90.

[0054] At this time, by introducing a material (charcoal only, and / or a material containing charcoal (including carbonized material)) in an amount sufficiently smaller than the amount of existing soil 90 removed, or by using a portion of the removed soil 90 as so-called topsoil for the first layer 10, in this embodiment, a portion of the existing soil 90 will play the role of the first layer 10 having a thickness suitable for planting and / or a thickness suitable for plants to grow naturally. Furthermore, the first layer 10 newly formed by the arrangement of the second layer 20 will have a second surface 14 in the thickness direction of the first layer 10 that is in contact with the outside air, and is different from the first surface 12 for planting and / or the first surface 12 for plants to grow naturally. In addition, this second surface 14 can create a state in which the entire root zone of the plant is less likely to become waterlogged. And, as described above, this first arrangement step brings the second layer 20 and the first layer 10 into direct contact, thus forming a boundary 30 for supplying water from the second layer 20 to the first layer 10.

[0055] Subsequently, a second placement step is performed in which a permeable third layer 40 is placed above the second layer 20. At this time, the third layer 40 is placed so as not to cover the entire second surface 14 of the first layer 10. As a result, the artificial soil 100 in this embodiment can be manufactured as shown in Figure 1.

[0056] In the artificial soil 100 of this embodiment, as described above, even if the third layer 40 is placed, the second surface 14 of the first layer 10 of this embodiment remains in a state where it can come into contact with the outside air. As a result, the first layer 10 is able to take in air from at least the second surface 14, and the entire root zone is less likely to become waterlogged. Therefore, as described above, by adopting the artificial soil 100 of this embodiment, respiration of the root zone of plants such as herbaceous plants (P in Figure 1) or trees (T in Figure 1) planted or growing naturally in the first layer 10 is ensured, and root rot can be prevented with high certainty.

[0057] Therefore, by employing the manufacturing method of the artificial soil 100 of this embodiment, the existing soil 90 will be utilized as the first layer 10 of the artificial soil 100 of this embodiment. As a result, it is noteworthy that the artificial soil 100 of this embodiment can be created relatively easily and / or relatively inexpensively using the existing soil 90 as the starting soil.

[0058] By following the manufacturing process described above, the artificial soil 100 shown in Figure 1 can be produced. The above example illustrates one method of manufacturing the artificial soil 100 in which existing soil 90 is used as the first layer 10 of the artificial soil 100 of this embodiment. However, the method of manufacturing the artificial soil 100 of this embodiment is not limited to the above example. For example, another possible method is to remove the existing soil 90 and then create a new first layer 10 for the artificial soil 100 of this embodiment.

[0059] [Results of various experiments and analyses on artificial soil 100] To confirm the technical effects of the artificial soil 100 described above, the inventors conducted the following experiments (E1), (E2), and (E3) using the laminated structure of the second layer 20 and the third layer 40 of this embodiment (Sample 1), and the structures (including single-layer and laminated structures) in comparative examples (Comparative Examples 1 to 3).

[0060] First, in order to match the initial conditions of the subjects of measurement, the amount of water (initial water absorption or initial water amount) that was initially supplied to the soil of Sample 1 and each comparative example was used as a baseline. Then, after 7 days had passed without continuous rainfall from that day, the (E1) surface temperature at 2 PM, (E2) surface temperature at 3 PM, and the amount of water evaporated from the soil of Sample 1 and each comparative example (E3) were measured. The inventors measured the aforementioned surface temperatures using an infrared sensor (PerfectPrime, model IR0005). In addition, the amount of water added to Sample 1 and each comparative example until the initial sufficient moisture level was achieved (additional water supply) was defined as the amount of water evaporated (evaporation).

[0061] The specific soil composition of Sample 1 and each comparative example (1-3) is as follows. Note that the representative example of pulverized coal (fine pulverized coal) in Sample 1 below is pulverized coal (moist pulverized coal) produced from the Aritagawa Biomass Power Plant (a small-scale, high-efficiency woody biomass heat and power supply system manufactured by URBAS). (Sample 1) Depth is approximately 380 mm and volume is approximately 35,000,000 mm³ 3 In this container, the thickness of the upper layer (corresponding to the third layer 40), which is "Hyuga soil," is approximately 100 mm (volume: approximately 10,000,000 mm). 3 ) and the thickness of the lower layer (corresponding to the second layer 20), which is pulverized coal, is 280 mm (volume: approximately 25,000,000 mm) 3 ) (Comparative Example 1) Sample 1 container initially filled only with water at approximately 24.5°C. (Comparative Example 2) Sample 1 container with only red clay added. (Comparative Example 3) Sample 1 container with only Hyuga soil added.

[0062] Table 1 below shows the results of various evaluations of the laminated structure of the second layer 20 and the third layer 40 of this embodiment (Sample 1), and the structures (including single-layer and laminated structures) of comparative examples (Comparative Examples 1 to 3). Figure 5 shows photographs (row x) and schematic diagrams (row y) illustrating the outline of some of the comparative experiments in this embodiment (Comparative Example 2 (column a) and Sample 1 (column b)).

[0063] [Table 1]

[0064] As shown in Table 1, the surface temperature of sample 1, in which the third layer 40 was placed above the second layer 20, at 2 PM and at 3 PM was confirmed to be lower than the surface temperatures of Comparative Examples 1 to 3. Furthermore, it was found that sample 1 could hold more moisture than Comparative Examples 2 and 3.

[0065] Furthermore, the amount of water evaporated from Sample 1 was greater than that evaporated from Comparative Example 1, which contained only water. It was also confirmed that the initial water absorption of Comparative Example 2 was an order of magnitude smaller than that of Sample 1 and Comparative Example 3. In addition, although not shown in Table 1 above, when the inventors measured a stone that does not retain water, it was found that the maximum surface temperature of the stone rose to 59.4 degrees Celsius at 3 PM. As a result, the difference between the surface temperature of the stone and the surface temperature of Sample 1 at 3 PM was 32.4 degrees Celsius. It is noteworthy that Sample 1, equipped with the second layer 20 and the third layer 40, achieved the aforementioned temperature difference relative to the stone under direct sunlight.

[0066] Based on the measurement results shown in Table 1, it can be said that by using Sample 1, which has a layer containing charcoal and / or carbonized material in the lower layer, the surface temperature of the soil can be kept lower for a longer period of time by utilizing the evaporation of water, compared to soil consisting only of Hyuga soil with a certain degree of water retention capacity (Comparative Example 3). Therefore, with the artificial soil 100 of this embodiment, which has the same configuration as Sample 1, the occurrence of the heat island phenomenon can be suppressed by taking advantage of the high water retention capacity of the second layer 20.

[0067] <Second Embodiment> The artificial soil 200 of this embodiment is the same as that of the first embodiment, except that the third layer 40 of the artificial soil 100 of the first embodiment is not present. Therefore, explanations that overlap with the first embodiment can be omitted.

[0068] Figure 6 is a diagram showing the schematic configuration of the artificial soil 200 in this embodiment. As shown in Figure 6, the first layer 10 of the artificial soil 200 in this embodiment has a second surface 14 in the thickness direction of the first layer 10 that is in contact with the outside air, which is different from the first surface 12 for planting and / or the first surface 12 for the natural growth of plants.

[0069] In this embodiment, as described above, since the third layer 40 is not placed on the second layer 20, for example, if the thickness of the second layer 20 is made the same as the second layer 20 in the first embodiment, a wider surface area of ​​the second surface 14 that can be exposed to the outside air can be secured. As a result, plants such as wildflowers (P in Figure 1) or trees (T in Figure 1) planted or growing naturally in the first layer 10 can more reliably enjoy the air supplied from the second surface 14 (the second surface 14 in the first layer 10) which is less or almost unaffected by the second layer 20, which has high water retention properties, and thus root rot of these plants can be prevented with greater certainty.

[0070] On the other hand, if the contact area between the second surface 14 of the first layer 10 and the outside air is made the same as the contact area of ​​the second layer 20 in the first embodiment, the thickness of the second layer 20 can be increased because there is no third layer 40, thus further enhancing the water retention capacity of the second layer 20.

[0071] Furthermore, by positioning the water-retentive second layer 20 such that its surface is lower than the surface of the first layer 10, for example, the water absorption capacity of the artificial soil 200 can be improved by utilizing the water-retentive properties of the second layer 20. As a result, the artificial soil 200 of this embodiment can mitigate the effects of heavy rain, such as so-called "guerrilla downpours" and "linear rainbands." Moreover, because the second layer 20, which contains charcoal and / or carbonized material, has higher water retention than ordinary soil, it is possible to increase the amount of heat from the heat of vaporization (latent heat) when the water retained by the second layer 20 evaporates, and / or to extend the time over which the heat of vaporization is removed from the second layer 20. As a result, the artificial soil 200 of this embodiment can suppress the occurrence of the heat island phenomenon.

[0072] <Third Embodiment> In the artificial soil 300 and artificial soil 400 of this embodiment, the second layer 20 in the artificial soil 200 of the second embodiment is the same as in the first embodiment, except that it is located in at least a portion of the lower layer side of the first layer 10. Therefore, descriptions that overlap with the first and second embodiments can be omitted.

[0073] Figure 7 shows the general configuration of the artificial soil 300 in this embodiment. Figure 8 shows the general configuration of another artificial soil 400 in this embodiment. In the artificial soil 400 shown in Figure 8, for the sake of clarity, the boundary between the first layer 10 and the second layer 20, which will be described later, is formed by a combination of straight lines in the horizontal direction of the paper and straight lines in the vertical direction of the paper. However, it is also possible to adopt an embodiment of the artificial soil 400 in which the boundary is formed by a curve only, or by including both a curve and a straight line. In this embodiment, the embodiment shown in Figure 8 shows an example in which at least a part of the second layer 20 is in contact with a surface of the first layer 10 along the thickness direction.

[0074] In the artificial soil 300 shown in Figure 7, a portion of the second layer 20 is arranged over the entire lower layer of the first layer 10. Therefore, in this example, the volume occupied by the water-retentive second layer 20 can be larger compared to the artificial soil 200 of the second embodiment. Consequently, by adopting the artificial soil 300, for example, improved rainwater absorption capacity can be achieved by utilizing the water-retentive capacity of the second layer 20 more effectively than with the artificial soil 200. As a result, the artificial soil 300 of this embodiment can mitigate the effects of heavy rain, such as so-called "guerrilla downpours" and "linear rainbands," more effectively than the artificial soil 200.

[0075] Here, the inventors considered it important to consider that the presence of a large amount of charcoal and / or carbonized material in the second layer 20 could cause the soil's pH to become alkaline, which could have a negative impact on plant growth or development.

[0076] An example that reflects the above idea is the artificial soil 400 shown in Figure 8. In the artificial soil 400 shown in Figure 8, a portion of the second layer 20 is located on the lower side of the first layer 10. Furthermore, in the artificial soil 400, the boundary between the first layer 10 and the second layer 20 is formed in a step-like manner, so to speak, in a cross-sectional view, where the thickness of the second layer 20 decreases in stages. In other words, in a cross-sectional view as shown in Figure 8, the second layer 20 on the lower side of the first layer 10 is positioned such that the volume occupied by the second layer 20 containing charcoal and / or carbonized material decreases as the distance from the interface between the first layer 10 and the second layer 20 near the surface (or, to put it another way, the contact point or boundary between the second surface 14 and the second layer 20) increases.

[0077] As shown in Figure 8, another possible approach is to reduce or suppress the aforementioned effects on the first layer 10 due to a change in the soil's pH value to alkalinity by ensuring that the volume occupied by the second layer 20, which contains charcoal and / or carbonized material, decreases as the distance from the interface between the first layer 10 and the second layer 20 near the surface increases.

[0078] Furthermore, in the example shown in Figure 8, the boundary between the first layer 10 and the second layer 20 is formed in a step-like manner in cross-sectional view, so the total area constituting the boundary between the first layer 10 and the second layer 20 may be larger than the total area of ​​the artificial soil 300 in this embodiment. As a result, the water-retentive second layer 20 can supply moisture to the first layer 10 with greater certainty; in other words, the ability of moisture to penetrate / move from the second layer 20 to the first layer 10 can be exerted with greater certainty. Note that in the example in Figure 8, the boundary between the first layer 10 and the second layer 20 is shown as a step-like manner in cross-sectional view, where the thickness of the second layer 20 decreases in stages, but the same effect can be achieved even if the thickness of the second layer 20 decreases uniformly instead of being step-like.

[0079] Furthermore, as shown in Figure 7, even if the thickness or volume of the second layer 20 located below the first layer 10 is uniform, another possible configuration of the artificial soil 300 or artificial soil 400 of this embodiment is to make the charcoal and / or carbide content (or density) of the second layer 20 located below the first layer 10 lower than the charcoal and / or carbide content (or density) of the second layer 20 in other areas.

[0080] <Modified example of the second embodiment (1)> The artificial soil 500 in this modified example is the same as in the first embodiment, except that the first layer 10 in the artificial soil 200 of the second embodiment has a second surface 14a that is inclined from the first surface 12 toward the thickness direction of the first layer 10. Therefore, explanations that overlap with the first and second embodiments can be omitted.

[0081] Figure 9 shows the general structure of the artificial soil 500 in this modified example (1). As shown in Figure 9, the first layer 10 of the artificial soil 500 in this modified example has a second surface 14a that slopes toward the thickness direction from the first surface 12.

[0082] In this modified example (1), the artificial soil 500 also has a second surface 14a that is different from the first surface 12 and is in contact with the outside air. Furthermore, as shown in Figure 9, since the second surface 14a is a surface that is inclined toward the thickness direction from the first surface 12, the surface area that is in contact with the outside air (in other words, the surface area that can take in air from the outside) is larger than the second surface 14 of the first embodiment. As a result, it is possible to enjoy air supplied from the second surface 14a (the second surface 14a of the first layer 10), which has little or no influence from the second layer 20, which can have high water retention, with greater certainty. For this reason, by adopting the artificial soil 500 of this modified example, root rot of plants planted or growing naturally in the first layer 10 (for example, flowers (P in Figure 9) or trees (T in Figure 9)) can be prevented with greater certainty.

[0083] <Modification of the second embodiment (2)> The artificial soil 600 in this modified example is the same as in the first embodiment, except that the first layer 10 of the artificial soil 200 in the second embodiment has a first surface 12a which is substantially flat but has irregularities, and a second surface 14b which is different from the first surface 12a and includes a substantially flat but irregular surface. Therefore, explanations that overlap with the first and second embodiments can be omitted.

[0084] Figure 10 shows the general structure of the artificial soil 600 in this modified example (2). As shown in Figure 10, the first surface 12a of the first layer 10 of the artificial soil 600 in this modified example is approximately flat, but not horizontal. Therefore, in this example of the modified example, the existence of the second surface 14b can be confirmed by using a straight line (the dashed line in Figure 10) that connects a starting point S, which is considered to be the edge of the approximately flat surface, to another point E on that surface, and determining whether a surface different from the first surface 12a, which is the aforementioned approximately flat surface, is inclined in the thickness direction with respect to the straight line on the first surface 12a (inclined at an angle represented by θ in Figure 10).

[0085] As described above, the artificial soil 600 of this modified example (2) also has a second surface 14b that is different from the first surface 12a, is inclined in the thickness direction of the first layer 10 and is in contact with the outside air, in addition to the first surface 12a. Furthermore, as shown in Figure 10, the second surface 14b is a surface that is substantially parallel to the first surface 12a but has irregularities, so the surface area that is in contact with the outside air (in other words, can take in air from the outside air) can be larger than the second surface 14 of the first embodiment. As a result, it is possible to enjoy air supplied from the second surface 14b (the second surface 14b of the first layer 10), which is less or almost unaffected by the second layer 20, which can have high water retention, with greater certainty. For this reason, by adopting the artificial soil 600 of this modified example, root rot of plants planted or growing naturally in the first layer 10 (for example, herbaceous plants (P in Figure 10) or trees (T in Figure 10)) can be prevented with greater certainty.

[0086] In Figure 10 of this modified example, plants, represented by flowers (P'), are shown growing from the surface of the second surface 14b. However, even in this example, the plants do not completely cover the second surface 14b of this modified example. Therefore, since the second surface 14b of this modified example remains in a state where it can still be exposed to the outside air, the plants can enjoy the air supplied from the second surface 14b (the second surface 14b in the first layer 10), where the influence of the second layer 20, which has high water retention, is small or almost nonexistent. Thus, root rot of the plants can be prevented with high certainty. Even if the entire second surface 14b were covered by the plants, the effects of this modified example can still be achieved as long as air exchange with the outside air can occur by utilizing the gaps in the soil's aggregate structure, etc.

[0087] As described above, the artificial soil 600 of this modified example (2) can promote greening even in urban areas and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment. Furthermore, since the artificial soil 600 includes a water-retentive second layer 20 positioned in contact with the first layer 10, it is possible to maintain a state where moisture can freely move between the second layer 20 and the first layer 10, while the second layer 20 can supply moisture to the first layer 10. In other words, the ability of moisture to permeate / move from the second layer 20 to the first layer 10 can be exercised. As a result, the artificial soil 600 can suppress the occurrence of the heat island phenomenon and promote greening, thereby realizing the conservation, creation, and regeneration of a sustainable natural or living environment.

[0088] <Modified form of the second embodiment (3)> The artificial soil 200a in this modified example is the same as in the second embodiment, except that the second layer 20 in the artificial soil 200 of the second embodiment is changed to a second layer 220. Therefore, descriptions that overlap with the first and second embodiments can be omitted.

[0089] Figure 11 shows the general composition of the artificial soil 200a in this modified example. In this modified example, the second layer 220 is composed of a mixture of crushed stone, gravel, crushed stone run, and one selected from the group of recycled materials mentioned above, and carbonized material. The carbonized material that can be used in this modified example is not particularly limited, but typical examples of carbonized material include powdered charcoal, bamboo charcoal, black charcoal, white charcoal, sawdust charcoal, crushed wood charcoal, and / or carbonized organic material derived from plants (made from pruned branches, thinned wood, charcoal derived from gasification wood biomass power generation, waste wood, food residue, livestock excrement, rice husks, rice, straw, nut shells, sewage sludge, paper sludge, industrial waste, and / or general waste). It should be noted that the inclusion of a mixture of crushed stone, gravel, crushed stone run, and one selected from the group of recycled materials mentioned above, and biochar in the second layer 220 is a preferred embodiment from the viewpoint of implementing carbon sequestration. Here, the aforementioned "biochar" typically includes materials made from pruned branches, thinned wood, charcoal derived from gasified wood biomass power generation, waste wood, food residue, livestock excrement, rice husks, rice, straw, nut shells, sewage sludge, paper sludge, industrial waste, and / or general waste. Furthermore, using a portion of the surface as a road surface such as asphalt is desirable from the standpoint of increasing the land use rate in cities. When using the road surface as a sidewalk, it is preferable to use crushed stone to a thickness of approximately 100 mm for that sidewalk.

[0090] In one example of the manufacturing method for the modified artificial soil 200a, for example, the second layer 220 can be manufactured by attaching, covering, or adding carbonized material to crushed stone, gravel, crushed stone run, and one of the aforementioned recycled materials used in roadbeds such as sidewalks, and then returning it to the roadbed. The thickness of the crushed stone or gravel to which the carbonized material is attached, covered, or added, i.e., the thickness of the second layer 220, can be appropriately adjusted to achieve effective water retention and aeration while maintaining the strength of the roadbed.

[0091] By adopting the artificial soil 200a of this modified version, it is possible to improve water retention while maintaining aeration compared to conventional roadbeds. Furthermore, by adopting artificial soil 200a, for example, the roots of tall trees planted in planting areas can utilize the moisture in the soil. As a result, the growth of tall trees improves, and problems such as root uprooting onto the surface of sidewalks made of asphalt, stone, or brick (not shown), which may make up part of the upper layer of the second layer 220, become less likely. Alternatively, from another perspective, the artificial soil 200a of this modified version can greatly contribute to improving the water (moisture) retention capacity of existing materials that constitute the roadbed.

[0092] <Fourth Embodiment> The artificial soil 700 of this embodiment is the same as that of the second embodiment, except that the first layer 10 in the artificial soil 200 of the second embodiment is changed to a first layer 10a that does not have second surfaces 14, 14a. Therefore, explanations that overlap with the first and second embodiments can be omitted.

[0093] Figure 12 is a diagram showing the general configuration of the artificial soil 700 in this embodiment. As shown in Figure 12, the artificial soil 700 in this embodiment comprises a first layer 10a having a thickness that allows for planting and / or allows plants to grow naturally, and a second layer 20 that is in contact with the first layer 10a.

[0094] More specifically, in this embodiment, the first layer 10a contains soil components and has a thickness that allows for the planting of plants such as flowers (P in Figure 1) or trees (T in Figure 1), and / or allows plants to grow naturally. The second layer 20 contains charcoal and / or carbonized material and is arranged in contact with the first layer 10a. In addition, the second layer 20 in this embodiment is in contact with the surface of the first layer 10a along the thickness direction.

[0095] In addition, in the artificial soil 700, the first layer 10a has a first surface 12 for planting and / or for plants to grow naturally. The "soil components" that the first layer 10a in this embodiment may contain are the same as the materials that can be used in the first layer 10 of the first embodiment, on which flowers or trees can grow. Furthermore, the "charcoal" and "carbonized material" that the second layer 20 in this embodiment may contain are the same as the "charcoal" and "carbonized material" that can be used in the first embodiment.

[0096] As described above, the artificial soil 700 of this embodiment includes a water-retentive second layer 20 arranged in contact with the first layer 10a. By configuring the second layer 20 to be in direct contact with the first layer 10a, the water-retentive second layer 20 can supply water to the first layer 10a while maintaining a state in which water can freely move between the second layer 20 and the first layer 10a. In other words, the ability of water to penetrate / move from the second layer 20 to the first layer 10a can be exercised.

[0097] As a result, if there are plants planted and / or naturally growing in the first layer 10a, these plants can enjoy the water supplied (discharged) from the second layer 20 through the first layer 10a. This makes it possible to reduce, for example, the number of times or the amount of water required to maintain the plants in the first layer 10a within a certain period, thereby significantly reducing the burden of plant maintenance. This reduction in the burden of plant maintenance can greatly contribute to promoting greening and the conservation, creation, and regeneration of a sustainable natural or living environment. Furthermore, because the burden of plant maintenance can be reduced, the use of the artificial soil 700 of this embodiment when planting various plants in public places (e.g., parks, green spaces, etc.) is a suitable embodiment from the viewpoint of promoting the effective use of tax money.

[0098] As described above, with the artificial soil 700, which is arranged in contact with the first layer 10a and has a second layer 20 that has water retention properties, it is possible to use charcoal and / or carbonized material to supply the water retained by the second layer 20 to the first layer 10a (in other words, to permeate / move water into the first layer 10a). As a result, plants planted in the first layer 10a can benefit from the water supplied (discharged) from the second layer 20.

[0099] Therefore, according to this embodiment, even in urban areas, it is possible to promote greening and contribute to the preservation, creation, and regeneration of a sustainable natural or living environment.

[0100] In this embodiment, the artificial soil 700 includes a first layer 10a that does not have the second surface 14 of the first layer 10 adopted in the first embodiment and the second surface 14a adopted in the modified example (1) of the second embodiment. Therefore, it is possible to prevent water spoilage, animal intrusion, and the breeding of mosquitoes and insects under waterlogged conditions with greater certainty. In particular, when the artificial soil 700 is isolated from rivers, etc., placing the second layer 20, which has high water retention properties by containing charcoal and / or carbonized material and plays a role in supplying moisture to the first layer 10a, in direct contact with the first layer 10a that does not have the second surface mentioned above, will allow the second layer 20 to absorb a larger amount of rainwater or other moisture.

[0101] <Modification of the fourth embodiment (1)> The artificial soil 700a in this modified example is the same as that of the fourth embodiment, except that the second layer 20 in the artificial soil 700 of the fourth embodiment is changed to a second layer 220. Therefore, explanations that overlap with the first to fourth embodiments and each of the modified examples can be omitted.

[0102] Figure 13 shows the general structure of the artificial soil 700a in this modified example. In this modified example, as in the modified example (3) of the second embodiment described above, the second layer 220 is composed of a mixture of crushed stone, gravel, crushed stone run and one selected from the group of recycled materials mentioned above, and carbonized material.

[0103] By adopting the artificial soil 700a of this modified version, it is possible to improve water retention while maintaining aeration compared to conventional roadbeds. Furthermore, by adopting the artificial soil 700a, space for the roots of trees planted in planting areas can be secured. As a result, the growth of trees will improve, and problems such as root uprooting onto the surface of sidewalks made of asphalt, stone, or brick (not shown), which may make up part of the upper layer of the second layer 220, will be less likely to occur. Alternatively, from another perspective, the artificial soil 700a of this modified version can greatly contribute to improving the water (moisture) retention capacity of existing materials that constitute the roadbed.

[0104] <Modification of the fourth embodiment (2)> The artificial soil 700b of this modified example is the same as that of the fourth embodiment, except that it comprises multiple second layers 20. Therefore, explanations that overlap with the first to fourth embodiments and each of these modified examples can be omitted.

[0105] Figure 14 shows the general structure of the artificial soil 700b in this modified example. In this modified example, multiple second layers 20 are provided as shown in Figure 14. Furthermore, each of the multiple second layers 20 in this modified example has a smaller, narrower, and / or shallower area compared to the area constituting the second layer 20 in the fourth embodiment. In other words, multiple second layers 20 are arranged within the area constituting the first layer 10a in this modified example.

[0106] An example of a method for producing the artificial soil 700b of this modified example is as follows:

[0107] Artificial soil 700b comprising multiple second layers 20 can be produced by first forming multiple non-penetrating holes in a portion of the surface (first surface 12) of the first layer 10a, which is existing soil and can be the target of planting and / or the natural growth of plants, using a known excavator, and then performing a placement step in which only water-retentive charcoal, only carbonized material, or a material containing said charcoal and / or carbonized material (a mixture of "soil component" and "charcoal", or a mixture of "soil component" and "carbonized material") is placed to fill or bury the non-penetrating holes. It is also a preferred embodiment to place a layer corresponding to a third layer (not shown) on top of the second layers 20.

[0108] Incidentally, the multiple second layers 20 in this modified example can be arranged at fixed or indeterminate intervals when viewed on the first surface 12. Furthermore, as described above, each of the multiple second layers 20 is smaller, narrower, and / or shallower than the area constituting the second layer 20 in the fourth embodiment, thus facilitating construction during the arrangement process of each second layer 20.

[0109] In addition, since each second layer 20 of the artificial soil 700b of this modified example is formed in a relatively small area, it is noteworthy that the strength of the existing soil is easily maintained while exhibiting the water retention performance of each second layer 20 and the water supply performance from each second layer 20 to the first layer 10a. For example, having part or all of a large area (such as a sports field, a plaza with grass or trees, or a pedestrian zone) covered with the artificial soil 700b of this modified example is a preferred embodiment from the viewpoint of achieving both highly reliable water retention of rainwater and other moisture by each second layer 20, and the replenishment of the soil (in this modified example, the first layer 10a).

[0110] <Fifth Embodiment> The artificial soil 800 of this embodiment is the same as that of the first embodiment, except that the artificial soil 100 of the first embodiment is changed to a first layer 10a that does not have a second surface. Therefore, explanations that overlap with the first embodiment can be omitted.

[0111] Figure 15 shows the general configuration of the artificial soil 800 in this embodiment. As shown in Figure 15, the artificial soil 800 of this embodiment comprises a first layer 10a having a thickness that allows for planting and / or allows plants to grow naturally, a second layer 20 in contact with the first layer 10a, and a third layer 40 provided above the second layer 20.

[0112] More specifically, in this embodiment, the first layer 10a contains soil components and has a thickness that allows for the planting of plants such as flowers (P in Figure 1) or trees (T in Figure 1), and / or allows plants to grow naturally. The second layer 20 contains charcoal and carbonized material and is arranged in contact with the first layer 10a. The third layer 40 is arranged above the second layer 20 and is permeable to water. In addition, the second layer 20 and the third layer 40 in this embodiment are in contact with the surface of the first layer 10a along the thickness direction.

[0113] Furthermore, in this embodiment as in the first embodiment, it is possible to actively increase the content ratio of charcoal and carbides in the constituent materials of the second layer 20, which the second layer 20 may contain. Therefore, from the viewpoint of improving the water retention of the second layer 20, the preferred content ratio (volume %) of "charcoal" and / or "carbides" that the second layer 20 may contain is more than 20% and 100% or less. Also, in the second layer 20 where planting is not actively anticipated, the preferred content ratio (volume %) of "charcoal" and / or "carbides" focusing solely on water retention is 30% or more and 100% or less (more preferably 40% or more and 100% or less). Furthermore, from the viewpoint of implementing carbon sequestration, one preferred embodiment is that the aforementioned "charcoal" and / or "carbides" are biochar, and the content ratio (volume %) of "biochar" in the second layer 20 is 50% or more (preferably 70% or more) and 100% or less.

[0114] In addition, as described above, since the second layer 20 is arranged to be in direct contact with the first layer 10a, the second layer 20 can also function as a suitable source of moisture, supplying moisture from the second layer 20 to the first layer 10a via the boundary 30 between the second layer 20 and the first layer 10a. The examples of constituent materials other than charcoal and carbides in the second layer 20 are the same as the "soil constituent materials" that the first layer 10a may contain.

[0115] Furthermore, similar to the first embodiment, the third layer 40 can contribute to lowering the ambient temperature (outside temperature) by, for example, utilizing capillary action to promote the evaporation of moisture that may be contained in the second layer 20 and / or the third layer 40. In addition, providing, for example, a sandbar-like design on the surface of the third layer 40 is preferable from the viewpoint of forming an appearance that appeals to human vision.

[0116] Furthermore, the fact that the third layer 40 has water retention properties in addition to the water permeability described above is a preferred embodiment because it helps the artificial soil 800 to achieve a water retention capacity that exceeds that of the second layer 20, and thus can retain moisture for a longer period of time. In addition, because the material constituting the third layer 40 has a large surface area and good permeability, more water evaporation from the soil surface occurs, and heat transfer using latent heat can be realized more efficiently.

[0117] By employing the artificial soil 800 of this embodiment, the water-retentive second layer 20 can supply water to the first layer 10a while maintaining a state in which water can freely move between the second layer 20 and the first layer 10a. In other words, the ability of water to permeate / move from the second layer 20 to the first layer 10a can be exercised.

[0118] As a result, if there are plants planted and / or naturally growing in the first layer 10a, these plants can enjoy the water supplied (discharged) from the second layer 20 through the first layer 10a. This makes it possible to reduce, for example, the number of times or the amount of water required to maintain the plants in the first layer 10a within a certain period, thereby significantly reducing the burden of plant maintenance. This reduction in the burden of plant maintenance can greatly contribute to promoting greening and the conservation, creation, and regeneration of sustainable natural and living environments. Furthermore, because the burden of plant maintenance can be reduced, the use of the artificial soil 800 of this embodiment when planting various plants in public places (e.g., parks, green spaces, etc.) is a suitable embodiment from the viewpoint of promoting the effective use of tax money.

[0119] As described above, with the artificial soil 800, which is arranged in contact with the first layer 10a and has a second layer 20 that has water-retaining properties, it is possible to use charcoal and / or carbonized material to supply the moisture retained by the second layer 20 to the first layer 10a (in other words, to permeate / move moisture into the first layer 10a). As a result, plants planted in the first layer 10a can benefit from the moisture supplied (discharged) from the second layer 20.

[0120] Therefore, according to this embodiment, even in urban areas, it is possible to promote greening and contribute to the preservation, creation, and regeneration of a sustainable natural or living environment.

[0121] <Modified example of the fifth embodiment (1)> Figure 16 shows the general configuration of the artificial soil 800' in this modified example (1). The artificial soil 800' in this modified example is the same as the artificial soil 800 of the fifth embodiment, except that the third layer 40 comprises one or more soil components and has a thickness suitable for planting and / or for plants to grow naturally. Therefore, descriptions that overlap with the first and fifth embodiments can be omitted.

[0122] As shown in Figure 16, in this modified example, a new soil 80a and / or existing soil 90, which contains soil components and has a thickness suitable for planting and / or for plants to grow naturally, constitute or replace a part of the third layer 40 in a portion or all of the thickness direction of the third layer 40. The new soil 80b may be asphalt, stone, brick, etc. Furthermore, the location of the new soil 80b is not limited to the location shown in Figure 16.

[0123] Similar to the first embodiment, the third layer 40 can, for example, facilitate the absorption of moisture by the second layer 20 by allowing surface water to penetrate early during rainfall and send it to the second layer 20, while also exhibiting high evaporation capacity during sunny days. In addition, as in this modified example, by providing the third layer 40 with one or more new soils 80a, 80b and / or existing soils 90, it is possible not only to demonstrate the performance of the third layer 40 itself, but also to provide an aesthetic appearance through planting and / or the arrangement of soils with design features.

[0124] Although not shown in the figures, in addition to the thickness direction described above, a modified example may also be adopted in which the new soil 80a, 80b and / or the existing soil 90 constitute or replace a part of the third layer 40 in a part of the planar direction (a plane perpendicular to the paper plane along the first surface 12).

[0125] Furthermore, in this modified example, the third layer 40 provided above the second layer 20 comprises the aforementioned soils 80a, 80b, and 90, but this modified example is not limited to the above example. For example, it is possible to adopt as another suitable example in this modified example that some or all of the new soils 80a, 80b and / or the existing soil 90 constitute or replace not only the third layer 40 but also some or all of the area of ​​the second layer 20 in the thickness direction and / or the planar direction.

[0126] <Modified examples of the fourth embodiment (3), (4)> The artificial soil 750 in this modified example is the same as that of the fourth embodiment, except that the second layer 20 of the artificial soil 700 in the fourth embodiment includes a storage tank 50 for a liquid 52 containing water. Therefore, descriptions that overlap with the first, second, and fourth embodiments can be omitted.

[0127] Figure 17 shows the general configuration of the artificial soil 750 in this modified example. As described above, in this modified example, the second layer 20 of the artificial soil 750 includes a storage tank 50 for a liquid 52 containing water. This storage tank 50 is made of at least a permeable material (for example, foamed material such as melamine foam or lightweight brick, coarse hemp, coarse cotton, woven fabric made of coarse artificial fibers, coarse knit, and / or coarse nonwoven fabric, or made of a non-permeable metal material, resin material, concrete, or ceramic with numerous small-diameter through holes on its sides and / or top surface). The fact that the storage tank 50 can serve as a water supply source is a preferred embodiment because it helps the artificial soil 750 to achieve a water retention capacity exceeding that of the second layer 20, and thus be able to retain moisture for a longer period of time.

[0128] Furthermore, the artificial soil 750 of this modified embodiment can be manufactured by placing part or all of the storage tank 50 within the second layer 20. As a specific example, similar to the first embodiment, the second layer 20 is constructed using the space created by removing part of the existing soil, and then a space for arranging part or all of the storage tank 50 is formed within a part of the second layer 20. Subsequently, the artificial soil 750 of this modified embodiment can be manufactured by placing the storage tank 50, manufactured using the aforementioned material which has sufficient pressure resistance when placed within the second layer 20, within this space. The liquid 52 containing water to be contained in the storage tank 50 can be contained, for example, by leaving the top of the storage tank 50 open without providing a lid, or by providing through holes in the lid of the storage tank 50 to take in rainwater. Alternatively, another embodiment may be adopted in which, instead of the above manufacturing method, the required amount of water retention is calculated in advance, and a storage tank 50 with a volume that matches that amount of water retention, or with a little extra capacity, is installed, and the upper layer second layer 20 is placed thereon.

[0129] In another modified example (modified example (4)), artificial soil 750', as shown in Figure 18, the amount of liquid 52 contained in the storage tank 50 can be artificially adjusted by supplying the liquid (labeled "L" in Figure 18) from a supply tank 54 containing water to the storage tank 50 via a supply pipe (for example, a supply pipe made of polyvinyl chloride).

[0130] According to the modified artificial soils 750, 750', the storage tank 50 can handle the amount of water that cannot be retained in the above-described embodiments. Therefore, it is possible to suppress the occurrence of the heat island phenomenon with greater certainty, and even in urban areas, it is possible to promote the replenishment of water represented by rainwater and heat transfer through the utilization of latent heat, thereby contributing to the preservation, creation, and regeneration of a sustainable natural and living environment.

[0131] <Modified form of the fifth embodiment (2)> The modified artificial soil 850 is the same as that of the fifth embodiment, except that the second layer 20 and the third layer 40 of the artificial soil 800 of the fifth embodiment are equipped with a storage tank 50 for a liquid 52 containing water. Therefore, descriptions that overlap with the first and fifth embodiments can be omitted.

[0132] Figure 19 shows the general configuration of the artificial soil 850 in this modified example. As described above, in this modified example, the second layer 20 and the third layer 40 of the artificial soil 850 are equipped with a storage tank 50 for a liquid 52 containing water. This storage tank 50 is the same as the storage tank 50 used in modified examples (3) and (4) of the fourth embodiment. Therefore, the fact that the storage tank 50 can serve as a water supply source is a preferred embodiment because it helps the artificial soil 850 to achieve a water retention capacity that exceeds the water retention capacity of the second layer 20 and the third layer 40, and to retain moisture for a longer period of time.

[0133] Furthermore, the artificial soil 850 of this modified embodiment can be manufactured by placing the entire storage tank 50 within the second layer 20 and the third layer 40. As a specific example, similar to the first embodiment, the second layer 20 and the third layer 40 are constructed using the space created by removing a portion of the existing soil, and then a space for arranging the entire storage tank 50 is formed within a portion of the second layer 20 and the third layer 40. Subsequently, the artificial soil 850 of this modified embodiment can be manufactured by placing the storage tank 50, which is manufactured using the aforementioned material having sufficient pressure resistance when placed within the second layer 20 and the third layer 40, into this space. Similar to the modification (3) of the fourth embodiment, the liquid 52 containing water to be stored in the storage tank 50 can be stored, for example, by taking in rainwater by providing through holes in the lid of the storage tank 50. Another possible manufacturing method involves, instead of the aforementioned manufacturing method, calculating the required amount of water to be retained in advance, installing a storage tank 50 with a volume that matches that amount of water, or with a little extra capacity, and arranging the second layer 20 and the third layer 40.

[0134] Furthermore, similar to modification (4) of the fourth embodiment, in other examples of this modification (not shown), the amount of liquid 52 contained in the storage tank 50 can be artificially adjusted by supplying the liquid 52 containing water from a supply tank to the storage tank 50 via a supply pipe.

[0135] <Example of modification of the fourth embodiment (5)> The artificial soil 900 of this modified example is the same as the artificial soil 700 of the fourth embodiment, except that the second layer 20 comprises a container 60 containing charcoal and / or carbonized material. Therefore, descriptions that overlap with the first, second, and fourth embodiments can be omitted.

[0136] Figure 20 shows the general configuration of the artificial soil 900 of this modified example. In this embodiment, as shown in Figure 20, the above-mentioned containment body 60 is arranged in a part of the second layer 20 of the artificial soil 900.

[0137] In this modified example, charcoal and / or carbides are contained within a container 60 that maintains a three-dimensional structure, so to speak, with a defined outer edge. By adopting a container 60 for containing charcoal and / or carbides, the ease of construction when forming the second layer 20 can be increased. Furthermore, for example, if the "charcoal" or "carbides" is "pulverized charcoal," it is possible to reliably prevent the pulverized charcoal from scattering into the surroundings during the construction of the second layer 20. In addition, since it is generally not possible to obtain carbides that have both high water retention capacity and high strength, adopting the container 60 of this modified example can contribute to maintaining the structure in the underground space and / or overcoming soft ground conditions.

[0138] Furthermore, an example of the container 60 in this modified example is made of a material that has at least water permeability (e.g., paper, corrugated cardboard, hemp, cotton, woven or knitted fabrics made of artificial fibers, and / or nonwoven fabrics), or is made of a non-water permeable resin material with numerous small-diameter through-holes on the sides and / or top surface. Other examples of the container 60 are sandbags or containers made of known resin materials (e.g., polyethylene or polypropylene), but small-diameter through-holes may be provided on the sides and / or top surface as needed to obtain water permeability.

[0139] As described above, the container 60 of this modified example is permeable to water. Therefore, in addition to its high water retention capacity, the charcoal and / or carbonized material contained in the container 60 has the ability to supply the retained moisture to the outside of the container 60, making it possible to supply the moisture retained by the second layer 20 to the first layer 10a (in other words, to permeate / move moisture into the first layer 10a). As a result, plants planted in the first layer 10a can benefit from the moisture supplied (discharged) from the second layer 20.

[0140] Therefore, according to this modified example, even in urban areas, it is possible to promote greening and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment.

[0141] In the example shown in Figure 20, one container 60 is arranged in the second layer 20, but the number of containers 60 arranged in the second layer 20 is not limited. Also, in this modified example, a container 60 containing charcoal and / or carbides occupies a portion of the second layer 20, but it is also possible to adopt a configuration in which the container 60 occupies the entire second layer 20. Therefore, the container 60 itself can also constitute a part of the second layer 20.

[0142] <Modified example of the fifth embodiment (3)> The artificial soil 950 of this modified example is the same as the artificial soil 800 of the fifth embodiment, except that the second layer 20 and the third layer 40 are equipped with a container 60 containing charcoal and / or carbonized material. Therefore, descriptions that overlap with the first, second, and fifth embodiments can be omitted.

[0143] Figure 21 is a diagram showing the general configuration of the artificial soil 950 of this modified example. In this embodiment, as shown in Figure 21, the above-mentioned containment body 60 is arranged in a part of the second layer 20 and the third layer 40 of the artificial soil 950.

[0144] In this modified example, the charcoal and / or carbonized material contained in the containment body 60 can be used to supply moisture held by the second layer 20 and / or the third layer 40 to the first layer 10a (in other words, to allow moisture to permeate / move into the first layer 10a). As a result, the plants planted in the first layer 10a can benefit from the moisture supplied (discharged) from the second layer 20 and / or the third layer 40.

[0145] Therefore, according to this modified example, even in urban areas, it is possible to promote greening and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment.

[0146] In Figure 21, one containment unit 60 is placed in the second layer 20 and the third layer 40, but the number of containment units 60 placed in the second layer 20 and the third layer 40 is not limited.

[0147] <Modified examples of the second embodiment (4), (5)> The modified artificial soil 250 is the same as the second embodiment, except that the second layer 20 of the artificial soil 200 in the second embodiment includes a storage tank 50 for a liquid 52 containing water. Furthermore, the modified artificial soil 250' is the same as the second embodiment, except that the second layer 20 of the artificial soil 200 in the second embodiment includes a storage tank 50 for a liquid 52 containing water and a supply tank 54 for the liquid 52. Therefore, descriptions that overlap with the first and second embodiments can be omitted.

[0148] Figure 22 shows the general structure of the artificial soil 250 in this modified example (modification (4)). Figure 23 shows the general structure of the artificial soil 250' in another modified example (modification (5)).

[0149] As described above, the second layer 20 of the artificial soil 250 includes a storage tank 50 for a liquid 52 containing water. Furthermore, the artificial soil 250' can artificially adjust the amount of liquid 52 contained in the storage tank 50 by supplying the liquid 52 from a supply tank 54 to the storage tank 50 via a supply pipe.

[0150] According to the modified artificial soil 250, 250', the storage tank 50 can handle the amount of water that cannot be retained in the second embodiment, thus more reliably suppressing the heat island phenomenon and promoting heat transfer through water replenishment, such as rainwater, and utilization of latent heat, even in urban areas, thereby contributing to the preservation, creation, and regeneration of a sustainable natural and living environment.

[0151] <Modified form of the first embodiment (2)> The modified artificial soil 150 is the same as in the first embodiment, except that the second layer 20 and the third layer 40 of the artificial soil 100 of the first embodiment are equipped with a storage tank 50 for a liquid 52 containing water. Furthermore, the storage tank 50 in the modified forms (3) and (4) of the fourth embodiment may be used. Accordingly, explanations that overlap with the first embodiment and the modified forms (3) and (4) of the fourth embodiment may be omitted.

[0152] Figure 24 shows the general configuration of the artificial soil 150 of this modified example. As described above, in this modified example, the second layer 20 and the third layer 40 of the artificial soil 150 are equipped with a storage tank 50 for a liquid 52 containing water. This storage tank 50 is the same as the storage tank 50 used in modified examples (3) and (4) of the fourth embodiment. Therefore, the fact that the storage tank 50 can serve as a water supply source is a preferred embodiment because it helps the artificial soil 150 to achieve a water retention capacity that exceeds the water retention capacity of the second layer 20 and the third layer 40, and to retain moisture for a longer period of time.

[0153] <Modification of the second embodiment (6)> The artificial soil 260 in this modified example is the same as the artificial soil 200 of the second embodiment, except that the second layer 20 of the artificial soil 200 of the second embodiment comprises a container 60 containing charcoal and / or carbonized material. Furthermore, the container 60 in the modified example (5) of the fourth embodiment may be used. Accordingly, explanations that overlap with the first embodiment, the second embodiment and the modified example (5) of the fourth embodiment may be omitted.

[0154] Figure 25 shows the general configuration of the artificial soil 260 of this modified example. In this embodiment, as shown in Figure 25, the above-mentioned containment body 60 is arranged in a part of the second layer 20 of the artificial soil 260.

[0155] In this modified example, as in the modified example (5) of the fourth embodiment, the containment body 60 is permeable to water. Therefore, in addition to its high water retention capacity, the charcoal and / or carbonized material contained in the containment body 60 has the ability to supply the retained moisture to the outside of the containment body 60, making it possible to supply the moisture retained by the second layer 20 to the first layer 10a (in other words, to permeate / move moisture into the first layer 10a). As a result, the plants planted in the first layer 10a can enjoy the moisture supplied (discharged) from the second layer 20.

[0156] Therefore, according to this modified example, even in urban areas, it is possible to promote greening and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment.

[0157] In the example shown in Figure 25, one container 60 is arranged in the second layer 20, but the number of containers 60 arranged in the second layer 20 is not limited. Also, in this modified example, a container 60 containing charcoal and / or carbides occupies a portion of the second layer 20, but it is also possible to adopt a configuration in which the container 60 occupies the entire second layer 20. Therefore, the container 60 itself can also constitute a part of the second layer 20.

[0158] <Modified form of the first embodiment (3)> The modified artificial soil 160 is the same as the artificial soil 100 of the first embodiment, except that the second layer 20 and the third layer 40 in the first embodiment are provided with a container 60 containing charcoal and / or carbonized material. Furthermore, the container 60 in the modified example (5) of the fourth embodiment may be used. Accordingly, descriptions that overlap with the first, second, and fifth embodiments may be omitted.

[0159] Figure 26 shows the general configuration of the modified artificial soil 160. In this embodiment, as shown in Figure 26, the above-mentioned containment 60 is arranged in a part of the second layer 20 and the third layer 40 of the artificial soil 160.

[0160] As described above, the containment body 60 of this modified example is permeable to water. Therefore, in addition to its high water retention capacity, the charcoal and / or carbonized material contained in the containment body 60 has the ability to supply the retained moisture to the outside of the containment body 60, making it possible to supply the moisture retained by the second layer 20 and / or the third layer 40 to the first layer 10a (in other words, to permeate / move moisture into the first layer 10a). As a result, plants planted in the first layer 10a can enjoy the moisture supplied (discharged) from the second layer 20 and / or the third layer 40.

[0161] Therefore, according to this modified example, even in urban areas, it is possible to promote greening and contribute to the conservation, creation, and regeneration of a sustainable natural or living environment.

[0162] In Figure 26, one containment 60 is placed in the second layer 20 and the third layer 40, but the number of containment 60 placed in the second layer 20 and the third layer 40 is not limited.

[0163] In the embodiments described above, the interfaces between the first layer 10, 10a and the second layer 20, the interface between the first layer 10, 10a and the third layer 40, and the interface between the second layer 20 and the third layer 40 are described as being clearly formed. However, the embodiments described above are not limited to examples where the boundaries are clearly defined as described above. For example, it is realistically possible that near the boundary between the first layer 10, 10a and the second layer 20, the materials constituting the first layer 10, 10a and the materials constituting the second layer 20 are mixed. However, even in such an example, the effects of each embodiment can be achieved as long as the first layer 10, 10a and the second layer 20 can be clearly distinguished in areas away from that vicinity. The same applies to the vicinity of the boundary between the first layer 10, 10a and the third layer 40, and the vicinity of the boundary between the second layer 20 and the third layer 40.

[0164] The disclosures of the embodiments described above are provided for the purpose of explaining those embodiments and are not intended to limit the present invention. In addition, other modifications that fall within the scope of the present invention, including other combinations of the embodiments described above, are also included in the claims. For example, one possible modification is the application of some or all of the components used in the first embodiment and its modifications, the second embodiment and its modifications, the third embodiment and its modifications, the fourth embodiment and its modifications, or the fifth embodiment and its modifications to a different embodiment or its modifications disclosed in this specification. [Industrial applicability]

[0165] The artificial soil and method for producing the artificial soil of the present invention can be widely used to suppress the occurrence of the heat island phenomenon and promote greening, thereby contributing to the conservation, creation, and regeneration of sustainable natural and living environments. [Explanation of Symbols]

[0166] 10,10a 1st layer 12,12a 1st page 14,14a,14b 2nd side 20,220 2nd layer 30, 30a, 30b, 30c, 30d Boundary between the first and second layers 40 3rd layer 50 Storage tanks 52 L of liquid containing water 54 Water-containing liquid supply tank 60 containment units 70 space 80a, 80b New soil 90 Existing soil 100, 150, 160, 200, 200a, 250, 250', 260, 300, 400, 500, 600, 700, 700a, 700b, 750, 750', 800, 800', 850, 900, 950 Artificial soil P,P' Flowers S Starting point T wood

Claims

1. A first layer containing soil components and having a thickness that allows for planting and / or the natural growth of plants, The first layer is in contact with a second layer containing charcoal and / or carbides, Artificial soil.

2. The second layer is adjacent to the first layer along the thickness direction, The thickness of the second layer is 100 mm or more and 5000 mm or less. The artificial soil according to claim 1.

3. The first layer is exposed to the outside air and has a second surface in the thickness direction of the first layer that is different from the first surface of the planting target and / or the natural habitat of the plant, or it is exposed to the outside air and has a second surface that is different from the first surface and is inclined toward the thickness direction from the first surface. Artificial soil according to claim 1 or claim 2.

4. The second layer is arranged on at least a portion of the lower side of the first layer. Artificial soil according to claim 1 or claim 2.

5. The second layer further comprises a storage tank for a liquid containing water. Artificial soil according to claim 1 or claim 2.

6. The char and / or the carbonized material is biochar, and The second layer comprises a mixture of one selected from the group consisting of crushed stone, gravel, crushed stone run and the aforementioned recycled materials, and the biochar. Artificial soil according to claim 1 or claim 2.

7. The second layer further comprises a permeable container for containing the char and / or the carbide, Artificial soil according to claim 1 or claim 2.

8. Above the second layer, there is a third layer having water permeability, water retention, and / or moisture evaporation properties. The third layer does not cover the entire second surface of the first layer. The artificial soil according to claim 2.

9. A water-permeable support structure is provided between the second and third layers, or on the second layer. Artificial soil according to claim 1 or claim 2.

10. The process includes a placement step of placing a second layer containing charcoal and / or carbonized material in contact with a first layer containing soil components and having a thickness that allows for planting and / or the natural growth of plants. A method for producing artificial soil.

11. The first layer is exposed to the outside air and has a second surface in the thickness direction of the first layer, or a second surface different from the first surface that is inclined toward the thickness direction from the first surface of the planting target and / or the natural growth target of the plant. A method for producing artificial soil according to claim 10.

Images