JP7722700B2 - Weed-proof greening sheet - Google Patents

Description

The present invention relates to a weed control and greening sheet that can simultaneously prevent weeds and promote greening, for example, on slopes and other surfaces.

One conventional technique for simultaneously preventing weeds and promoting greenery involves laying agricultural mulch film on the ground, drilling holes where necessary, and planting seeds or seedlings in those holes. This method prevents weeds through the weed-suppressing properties of the mulch film, while also allowing the growth of desired plants in the holes.

JP 2014-94000 A

However, the above method requires drilling holes in the mulch film on-site, which raises concerns that the increased work required by workers on slopes and other such sites could directly increase the risk of danger. Also, because mulch film is lightweight, it can easily be blown away by the wind before it can be secured in place.

As a technology that could solve the above problems, a greening method using a seeded weed control sheet that integrates multiple components, such as two sheets of nonwoven fabric, a poly sheet, a Russell net sheet, and a water-soluble seed sheet (see, for example, Patent Document 1), has been proposed. However, the structure of the seeded weed control sheet is complex and tends to be expensive.

Furthermore, in Patent Application No. 2021-121216, the applicant proposed a weed control greening sheet that prevents the growth of competing species while enabling the early growth of target species and reducing subsequent maintenance. The present invention seeks to provide a weed control greening product that can further improve weed control effectiveness and durability.

The present invention was made with the above in mind, and its purpose is to provide a highly durable weed-control and greening sheet that exhibits excellent weed-control effects while enabling the early growth of target species and reducing subsequent maintenance.

In order to achieve the above-mentioned object, the weed-control greening sheet of the present invention comprises a multi-layer weed-control sheet having a striped substrate bag, and at least the upper surface of the sparse portion of the multi-layer weed-control sheet arranged above the substrate bag is whitish, and at least the upper surface of the weed-control portion located away from the upper side of the substrate bag is dark-colored (Claim 1).

The above-mentioned weed-prevention greening sheet has sparse and dense portions arranged on the upper side of the base material bag, which is installed so that its longitudinal direction follows the contour lines of the slope, and the sparse portions may be located closer to the foot of the slope than the dense portions (Claim 2).

The weed control greening sheet has pocket sections for accommodating substrate bags and weed control sections arranged alternately from one end to the other, and the multi-layer weed control sheet is a double weed control sheet made up of two layers, a front tissue and a back tissue, with the front tissue located on the upper side of the weed control section and on the lower side of the pocket section, and the back tissue located on the lower side of the weed control section and on the upper side of the pocket section, and in the front tissue, the entire area constituting the pocket section is a sparse section where the constituent material is less dense and has a larger mesh than the area constituting the weed control section, and in the back tissue, the area constituting the pocket section is divided into a sparse section where the constituent material is less dense and has a larger mesh than the area constituting the weed control section, and a dense section where the constituent material is denser and has a smaller mesh, and the constituent material of the front tissue may be a dark color and the constituent material of the back tissue a white color (claim 3).

The present invention provides a highly durable weed-control greening sheet that exhibits excellent weed-control effects while enabling the early growth of target species and reducing subsequent maintenance.

In other words, when the weed control and greening sheet of the present invention (the invention as claimed in each claim of this application) is laid on a slope or the like, the multi-layer weed control sheet can suppress the germination and growth of competing species. Furthermore, by storing seeds and fertilizer of the target species in a substrate bag, for example, and ensuring that the substrate bag is strong enough not to hinder the target species from germinating or rooting, the germination and growth of the target species can be promoted. Even after the target species has been successfully grown in this way, the multi-layer weed control sheet's effect of suppressing the growth of competing species continues, thereby reducing maintenance and management. Furthermore, the weed control and greening sheet of the present invention can be constructed only from a multi-layer weed control sheet and a substrate bag, and this simplified construction is expected to result in cost savings.

In addition, with the weed control and greening sheet of the present invention, even if poor weed control (such as tears or widening of mesh size) occurs in some of the multiple layers constituting the multi-layer weed control sheet due to falling stones or deterioration over time, the weed control effect will be maintained as long as the remaining layers do not suffer from poor weed control. This means that the weed control function (such as the ability to inhibit the germination of buried seeds) is more likely to be exerted over the long term. Of course, it is also easy to increase the weed control effect by increasing the basis weight of some or all of the multiple layers. Moreover, if the multiple layers include two layers that are stacked one above the other without being completely fixed to each other across the entire surface, an air gap will exist between the two layers. This air gap enhances the heat retention of the weed control and greening sheet, which also has the effect of making buried seeds present on slopes, etc. where the weed control and greening sheet is installed more likely to wither and die due to heat. Furthermore, even if airborne seeds take root on the weed control greening fabric and those roots pass through the upper layer of the multi-layer weed control fabric, there is still no ground there, and at least the lower layer of the multi-layer weed control fabric is present, so those airborne seeds are likely to wither and die.

Furthermore, with the weed control greening sheet of the present invention, even if the upper layer of the multiple layers that make up the multi-layer weed control sheet is damaged or develops a gap due to UV degradation, full-scale UV degradation of the lower layers etc. will begin from that point, thereby significantly improving durability against UV degradation.

Furthermore, with the weed control greening sheet of the present invention, if the multi-layer weed control sheet and base bag are both water permeable, rainfall, etc. will supply moisture to the seeds of the target species inside the base bag. In particular, if the multi-layer weed control sheet contains the air layer described above, moisture will be more likely to be retained in that air layer, which will in turn create an environment in which moisture is continuously supplied to the seeds of the target species, improving the growth and rooting of the target species.

Furthermore, by changing the density of each layer of the multi-layer weed control sheet of the present invention, it is easy to freely control the amount of rainwater penetration and the degree of suppression of buried seeds from germinating, depending on the local geology, surrounding vegetation environment, weather environment, etc.

The weed-control greening sheet of the present invention takes advantage of the low weed-control function of the sparse sections to promote the germination and growth of seeds of the target species contained within the substrate bag. Furthermore, the sparse sections located on the entire or partial upper side of the substrate bag make it difficult for heat to build up in the space below these sparse sections and in the substrate bag located within this space, and by coloring at least the upper surface of the sparse sections located on the upper side of the substrate bag white, temperature increases in the substrate bag located below the sparse sections are suppressed, making it difficult for the target species within the substrate bag to wither and die due to high temperatures, thereby improving the survival of the target species.

In the weed-control greening sheet of the invention according to claim 2 , the low weed-control function of the sparse areas can be utilized to promote the germination and growth of the seeds of the target species contained within the substrate bag. Furthermore, by arranging not only sparse areas but also dense areas on the upper side of the substrate bag, the dense areas can firmly hold the substrate bag in place, thereby increasing the reliability of vegetation establishing from the substrate areas even in cases where the weed-control greening sheet is exposed to harsh natural environments after installation.

Furthermore, when the substrate bag is housed and held between the layers of a multi-layer weed control sheet, it is more likely that the dense portion in the upper layer of the substrate bag will adhere to the substrate bag, and as a result, the sparse portion will also adhere to the substrate bag. If the sparse portion does not adhere to the substrate bag and a gap is created between the substrate bag and the sparse portion above it, sprouts of the target species growing in that gap may be obstructed by the material making up the sparse portion, impairing germination ability. However, with the weed control greening sheet of the invention according to claim 2 , in which the sparse portion is more likely to adhere to the substrate bag as described above, target species that germinate from the substrate bag will be able to grow through the sparse portion more easily, thereby improving germination ability.

1A and 1B are perspective views of a weed-control and greening sheet according to an embodiment of the present invention, as viewed from above and below, respectively. 1A is a longitudinal cross-sectional view of the weed-control greening sheet laid on a slope, and FIG. 1B is a longitudinal cross-sectional view of a double weed-control sheet that constitutes the weed-control greening sheet. (A) is an explanatory diagram showing only the warp threads of both the front and back structures in the main part of the double weed control sheet, (B) is an explanatory diagram showing only the warp threads of the front structure extracted from (A), (C) is an explanatory diagram showing only the warp threads of the back structure extracted from (A), (D) is an explanatory diagram of the structure of the front structure showing the warp threads of the front structure shown in (B) together with the weft threads etc. that are entangled with them, and (E) is an explanatory diagram of the structure of the back structure showing the warp threads of the back structure shown in (C) together with the weft threads etc. that are entangled with them.

Embodiments of the present invention are described below.

The weed control and greening sheet S shown in Figures 1(A) and (B) comprises a double weed control sheet (an example of a multi-layer weed control sheet) 1 with multiple strip-shaped (long) substrate bags 2 that can be attached and detached. It is used by unfolding it on the target construction area, such as a slope N (see Figure 2(A)) or flat land where weed control and greening are to be simultaneously achieved, and then fixing (laying) it down with appropriate fixing devices (anchor pins, etc., not shown).

As shown in Figures 1(A) and 1(B), the double weed control sheet 1 is rectangular in plan view and has a total of three pockets 3 spaced apart in the X direction, which is its vertical (longitudinal) direction. Each pocket 3 extends in the Y direction, which is the horizontal (short) direction of the double weed control sheet 1. A substrate bag 2 can be inserted and removed from each pocket 3, which extends from one end of the double weed control sheet 1 to the other in the Y direction, from either end. Furthermore, in the double weed control sheet 1, the areas sandwiching each pocket 3 in the X direction are each configured as weed control sections 4; in other words, the weed control sections 4 and pockets 3 are arranged alternately from one end to the other in the X direction.

As shown in Figure 2 (B), the double weed control sheet 1 is made of a woven fabric with a two-layer sheet structure consisting of a front weed control section 5 and a back weed control section 6. The front weed control section 5 is located on the upper side of the weed control section 4 and on the lower side of the pocket section 3, while the back weed control section 6 is located on the lower side of the weed control section 4 and on the upper side of the pocket section 3.

More specifically, as shown in Figure 3(A), if we focus only on warp threads 5A (threads extending in the X direction shown in Figures 1(A) and (B)) that make up the face structure 5 and warp threads 6A (threads extending in the X direction shown in Figures 1(A) and (B)) that make up the back structure 6, they intersect so that in the weed-control section 4, warp threads 5A are located on the upper side and warp threads 6A are located on the lower side, and in the pocket section 3, warp threads 5A are located on the lower side and warp threads 6A are located on the upper side.

The warp threads 5A of the face structure 5 shown in Figure 3(A) are actually woven so that the weft threads 5B intertwine with them, as shown in Figure 3(E). Comparing Figures 3(A), (C), and (E) makes it easy to understand that the weft threads 5B intertwine with the warp threads 5A of the face structure 5 are woven so that they are dense in the weed control area 4 and sparse in the pocket area 3 (plain weave).

On the other hand, the warp threads 6A of the back structure 6 shown in Figure 3(A) are actually woven so that they intertwine with the weft threads 6B as shown in Figure 3(D). Comparing Figures 3(A), (B), and (D) makes it easy to understand that the weft threads 6B intertwine with the warp threads 6A of the back structure 6 are woven so that they are densely intertwined throughout the weed control section 4 and in parts of the pocket section 3, and sparsely intertwined in other parts of the pocket section 3 (plain weave).

Specifically, as shown in Figure 3 (D), the area of the backing weave 6 that forms the pocket portion 3 includes a dense portion 7 located toward one end in the X direction (see Figures 1 (A) and (B)) and a sparse portion 8 located toward the other end, with the dense portion 7 having a narrower area than the sparse portion 8, occupying, for example, 80% or less (preferably half or less) of the area of the sparse portion 8.

In this example, in the back weft structure 6, the weft threads 6B in the area that forms the weed-control section 4 are the same as the weft threads 6B in the area that forms the dense section 7, and the density (pitch in the X direction) of the weft threads 6B in both areas is also the same or approximately the same.

On the other hand, in the sparse portion 8, weft thread 6B is replaced with weft thread 6C, which is thinner than weft thread 6B, and is plain woven. The pitch of this weft thread 6C in the X direction is greater than the pitch of weft thread 6B in the dense portion 7. In other words, the density of weft thread 6C in the area that makes up sparse portion 8 is less than the density of weft thread 6B in the area that makes up dense portion 7.

In other words, in the back structure 6, the area that makes up the pocket portion 3 is divided into a sparse portion 8 where the constituent materials (warp and weft threads) are less dense and have a larger mesh size (i.e., less weed-controlling ability) than the area that makes up the weed-controlling portion 4, and a dense portion 7 where the constituent materials are denser and have a smaller mesh size (i.e., more weed-controlling ability), whereas in the front structure 5, the entire area that makes up the pocket portion 3 is a sparse portion 9 where the constituent materials (warp and weft threads) are less dense and have a larger mesh size (i.e., less weed-controlling ability) than the area that makes up the weed-controlling portion 4.

When this weed-control greening sheet S is laid on a slope N, for example, as shown in Figure 2(A), the double weed-control sheet 1 can mainly suppress the germination and growth of competing species through the weed-control portion 4.

Furthermore, sparse areas 8, 9 with low weed control function are provided in the holding positions (pocket portions 3) of the substrate bag 2 in the double weed control sheet 1. The sparse areas 8, 9 have one or more of the following structures or properties: lower density of constituent materials, lower strength, thinner, or more susceptible to deformation by external forces than the surrounding areas of the double weed control sheet 1 (weed control portions 4, dense portions 7), and are designed to at least be less likely to interfere with the germination and growth of the target species. In a weed control and greening sheet S configured in this way, the substrate bag 2 housed in the pocket portions 3 seals the sparse areas 8, 9, allowing the substrate bag 2 to compensate for the poor weed control function of the sparse areas 8, 9. Furthermore, for example, by storing seeds of the target species, fertilizer, etc. in the substrate bag 2 and making the substrate bag 2 strong enough so as not to hinder the germination or root growth of the target species (the sprouts and roots of the target species can easily break through), it is possible to take advantage of the low weed control function of the sparse portions 8, 9 and promote the germination and growth of the seeds of the target species stored in the substrate bag 2.

And even after the target species has been successfully grown in this way, the double weed control fabric 1 continues to suppress the growth of competing species, reducing the need for maintenance.

In addition, with the weed control greening sheet S of this example, the substrate bag 2 can be inserted into the pocket portion 3 to hold the substrate bag 2 in place on the double weed control sheet 1, making the process of holding the substrate bag 2 easy. Furthermore, since no components other than the double weed control sheet 1 are required to hold the substrate bag 2, costs associated with an increased number of components can be prevented. In other words, the weed control greening sheet S can be constructed using only the double weed control sheet 1 and the substrate bag 2, and costs can be reduced by simplifying the construction.

In addition, in the weed control and greening sheet S of this example, the base material bag 2 is held by the double weed control sheet 1 so that it is exposed on at least its underside. In this example, a sparse section 9 is provided on the underside (surface weave 5) of the pocket section 3, and the areas on the underside of the base material bag 2 inserted into the pocket section 3 where the warp threads 5A and weft threads 5B that make up the sparse section 9 do not come into contact are exposed on the underside. In a weed control and greening sheet S configured in this way, the base material bag 2, which is exposed on the underside of the double weed control sheet 1, can come into contact with the natural ground, etc., ensuring the germination and growth of the target seeds contained within the base material bag 2.

In addition, with the weed control greening sheet S of this example, even if a weed-control defect (such as a tear or widening of the mesh size) occurs in one of the two layers (top layer 5, bottom layer 6) that make up the double weed control sheet 1 due to a boulder falling or deterioration over time, the weed control effect will be maintained as long as the other layer does not experience a weed-control defect. This means that the weed control function (such as the ability to inhibit the germination of buried seeds) is more likely to be exerted over the long term. Of course, it is also easy to increase the weed control effect by increasing the basis weight of one or both of the two layers. Moreover, unless the two layers are completely and completely fixed together, an air gap will exist between them. This air gap enhances the heat retention of the weed control greening sheet S, which also has the effect of making buried seeds present on slopes N, etc., where the weed control greening sheet S is laid, more likely to wither and die due to heat. Furthermore, even if airborne seeds take root on the weed control greening sheet S and the roots pass through the upper layer of the double weed control sheet 1 (surface tissue 5 in the weed control section 4, and back tissue 6 in the pocket section 3), there is still no ground there and there is at least the lower layer of the double weed control sheet (back tissue 6 in the weed control section 4, and base bag 2 and surface tissue 5 in the pocket section 3), so the airborne seeds are likely to wither and die.

Furthermore, with this example of weed control greening sheet S, even if the upper layer (surface tissue 5 in the weed control section 4, back tissue 6 in the pocket section 3) of the two layers (surface tissue 5, back tissue 6) that make up the double weed control sheet 1 is damaged or develops a gap due to UV degradation, full-scale UV degradation of the lower layers (back tissue 6 in the weed control section 4, base bag 2 and surface tissue 5 in the pocket section 3) will begin at that point, thereby significantly improving resistance to UV degradation.

In addition, in the weed control greening sheet S of this example, if the double weed control sheet 1 and the substrate bag 2 are both water permeable (for example, the double weed control sheet 1 is woven and therefore slightly permeable to moisture), rainfall and other factors will supply moisture to the seeds of the target species in the substrate bag 2. Moisture is particularly likely to be retained between the upper and lower layers of the double weed control sheet 1 (surface tissue 5, back tissue 6), which in turn creates an environment in which moisture is continuously supplied to the seeds of the target species, improving the growth and rooting of the target species. For example, as shown in Figure 2(A), if the weed control greening sheet S is laid on a slope N so that the longitudinal direction of the substrate bag 2 follows the contour lines of the slope N, moisture retained between the upper and lower layers of the double weed control sheet 1 (surface tissue 5, back tissue 6) will be easily supplied to the substrate bag 2 at the foot of the slope. To increase the durability of this moisture supply effect, a material with water-retaining properties, such as a high-molecular-weight polymer, may be sandwiched between the upper and lower layers (surface tissue 5 and back tissue 6) of the double weed control sheet 1.

In addition, with the weed control greening sheet S of this example, by changing the density (the folding degree of the warp and weft threads, which are the constituent materials, and the mesh size, etc.) of the two layers (front structure 5 and back structure 6) of the double weed control sheet 1, it becomes easier to freely control the degree of rainwater penetration and the degree of suppression of germination of buried seeds to suit the local geology, surrounding vegetation environment, weather environment, etc.

Furthermore, in this example, the weed-control greening sheet S does not only have sparse sections 8 arranged on the upper side of the base material bag 2, but also has dense sections 7 arranged thereon, which allows the base material bag 2 to be firmly held in place by these dense sections 7, thereby increasing the reliability of vegetation growing on the base material section 2 even in cases where the weed-control greening sheet S is exposed to harsh natural environments after installation.

In addition, in this example of the weed-control greening sheet S, the pocket portion 3 is composed of two layers (top and bottom) (front and back layers 5 and 6), and the base bag 2 is sandwiched and firmly held between these two layers, making it easy to increase the adhesion of the base bag 2 to the pocket portion 3.

Furthermore, when the substrate bag 2 is contained and held (sandwiched) between the upper and lower layers (front and back tissues 5 and 6) of the double-layered weed control sheet 1, having both the sparse portions 8 and the dense portions 7 arranged on the upper side of the substrate bag 2, rather than only the sparse portions 8, makes it easier for the dense portions 7 in the upper layer (back tissue 6) of the substrate bag 2 to adhere closely to the substrate bag 2, and therefore the sparse portions 8 are also more likely to adhere closely to the substrate bag 2. If the sparse portions 8 do not adhere closely to the substrate bag 2 and a gap is formed between the substrate bag 2 and the sparse portions 8 above it, sprouts of the target seeds growing in that gap may be obstructed by the material (warp threads 6A, weft threads 6C) that makes up the sparse portions 8, impairing germination. However, in the weed control greening sheet S of this example, where the sparse portions 8 easily adhere to the substrate bag 2 as described above, target seeds that germinate from the substrate bag 2 can easily grow through the sparse portions 8, improving germination.

Furthermore, in the case of the weed control greening sheet S of this example, if the longitudinal direction of the substrate bag 2 is aligned with the contour lines of the slope N (see Figure 2(A)), and the weed control greening sheet S is positioned so that the dense portions 7 of the pocket portions 3 are on the slope toe side (this is easy to understand by looking at the weed control greening sheet S in Figure 1(A) as if the upper right side faces the slope toe side and the lower left side faces the slope toe side, and the pocket portions 3 in the figure extend along the contour lines), the dense portions 7 will function as a roof, so to speak, preventing airborne seeds and fine soil particles from entering the pocket portions 3. This will inhibit the growth and establishment of airborne weeds and other weeds, thereby improving the growth and establishment of the target species (introduced species) contained in the substrate bag 2.

The specific configuration of the weed-control greening sheet S is explained below.

The material for the double weed control sheet 1 (front and back layers 5 and 6) may be similar to the polyethylene used in so-called blue tarps.

The warp threads 5A, 6A and weft threads 5B, 6B that make up the double weed control sheet 1 can both be flat yarns with a width of approximately 3 mm, and the weft thread 6C can be a monofilament with a thickness of approximately 440 decitex (400 denier).

When a base material bag 2 with a diameter of 30 mm is attached to the pocket portion 3, the width of the stripe (width in the X direction) where no weft thread 5B is present in the sparse portion 9 may be approximately 40 to 50 mm, and the spacing between weft threads 6C in the sparse portion 8 may be, for example, approximately 10 mm in the X direction.

In the double weed control sheet 1, at least the upper surface of the sparse portions 8 located on the upper side of at least a portion (preferably more than half) of the substrate bag 2 is whitish. In other words, the sparse portions 8 located on the upper side of at least a portion of the substrate bag 2 prevent heat from building up in the space below these sparse portions 8 (the space within the pocket portion 3) and in the substrate bag 2 located within this space. Furthermore, by making at least the upper surface of the sparse portions 8 located on the upper side of the substrate bag 2 whitish, the temperature rise of the substrate bag 2 located below the sparse portions 8 is suppressed, making it less likely that the target species will wither or die due to high temperatures and improving the survival of the target species.

Furthermore, if the entire top surface of the weed control section 4 is a dark color such as black, the weed control section 4 will have excellent light-blocking properties, which is advantageous for suppressing the growth of buried species (weeds) when the double weed control sheet 1 (weed control greening sheet S) is laid on the ground, etc., and the weed control section 4 will also be less susceptible to UV degradation and have excellent weather resistance. In particular, if the entire top surface of the weed control section 4 is black, which has good infrared absorption properties, the weed control section 4 will be more likely to heat up when sunlight is incident on it, making it easier to wither and kill buried species (weeds) due to the heat.

In this example, the constituent materials of the front structure 5 (warp threads 5A, weft threads 5B) are dark colors such as black, and the constituent materials of the back structure 5 (warp threads 6A, weft threads 6B, 6C) are white. As a result, as shown in Figure 1(A), the upper surface of the weed control section 4 is dark, and the upper surface of the pocket section 3 is white. As a result, the dense section 7 that functions as the roof section described above is also white. If the dense section 7 serving as the roof section were to become hot, the space below it and the substrate bag 2 within this space would also become hot. However, by making the dense section 7 white, it is less likely to become hot, and ultimately the seeds of the target species in the substrate bag 2 can also be prevented from becoming hot.

However, since white threads are generally more susceptible to UV degradation than dark threads and tend to be weaker in strength and durability, the thin weft thread 6C may be made dark in color to prioritize strength and durability. Furthermore, if the backing fabric 6 that forms the upper layer of the pocket portion 3 is white and is expected to lose its holding power for the base bag 2 due to UV degradation, it is necessary to attach the target species while this holding power is maintained.

The substrate bag 2 contains the target species of plant substrate (e.g., seeds, bulbs, runners, etc.), as well as materials (substrates) suitable for the growth of the plant substrate, such as fertilizer, soil conditioner, and water-retaining material.

When laying the weed control greening sheet S configured as described above at the construction site, if the base material bags 2 are attached to each pocket portion 3 of the double weed control sheet 1 beforehand, the labor required for this attachment work on site will be reduced. This reduction in work is advantageous in reducing danger, particularly when the site has a steep slope. Furthermore, although the double weed control sheet 1 itself is lightweight, attaching even one heavy base material bag 2 to the double weed control sheet 1 also has the effect of making it less likely for the double weed control sheet 1 to be blown away by the wind when being laid down.

However, this is not a limitation. Instead of attaching a substrate bag 2 to each of the pockets 3 of the double weed control sheet 1 in advance, substrate bags 2 may be attached to only some of the pockets 3, or the sheet may be transported to the site without any substrate bags 2 attached, and then substrate bags 2 may be attached to the unattached pockets 3 at the site. From the perspective of making the double weed control sheet 1 less likely to be blown away by the wind, it is preferable to attach at least one substrate bag 2 to the double weed control sheet 1 in advance.

When the weed control greening sheet S configured as described above is laid on a slope N, rainwater is supplied to the ground from the sparse areas 8 through the inside or outside of the base material bag 2 underneath. This overcomes the weakness of the double weed control sheet 1, which is that the back side of the double weed control sheet 1 can dry out, weakening the slope N (loosening the ground), and there is no need to drill holes to overcome this weakness.

Furthermore, when the weed control greening sheet S is laid on a slope N, the speed at which rainwater flows over the double weed control sheet 1 tends to increase, a weakness of the double weed control sheet 1. This weakness can be overcome by the sparse sections 8, which have the function of draining and dispersing rainwater from the top surface of the double waterproof sheet 1 to the bottom side (the natural ground side).

In addition, the deterioration of the landscape when the weed-proof greening sheet S is laid on the construction site can be reduced by stripe-like greening achieved by the germination and growth of the target species from the substrate bags 2 arranged along the sparse sections 8 and 9 that extend in stripes. Furthermore, the weed control greening sheet S prevents the overgrowth of competing plants (mainly weeds), reducing the effort and management costs of weeding and preventing injuries caused by weeding. Furthermore, by appropriately spacing the pocket sections 3 (sparse sections 8, 9) or the base material bags 2 in the X direction and positioning each pocket section 3 (sparse sections 8, 9, base material bag 2) away from both ends of the double weed control sheet 1 in the X direction, strip-shaped greening is achieved. This means that the target plants growing in each base material bag 2 are less likely to have their sunlight blocked or suppressed by surrounding competing plants, and their sunlight is also less likely to be blocked by plants of the target species growing in other base material bags 2 adjacent in the X direction. This makes it easier to create an ideal growing environment for the target plants, which in turn contributes to earlier greening.

Furthermore, with weed control sheets that do not incorporate greening, sunlight reflected from the surface of the weed control sheet can become intense light that can easily enter the eyes of drivers of vehicles, potentially compromising driving safety. However, the weed control and greening sheet S of this example incorporates striped greening as described above, so not only do these greened areas not reflect sunlight as intense light, but the natural green color is also gentle on the eyes. Furthermore, as shown in Figure 1(A), most of the top surface of the weed control and greening sheet S is made up of dark-colored weed control sections 4, which do not reflect sunlight as intense light, thereby improving driving safety for vehicles, etc.

Furthermore, when laying the weed control greening sheet S on a slope, if the longitudinal direction (Y direction) of the sparse sections 8, 9 (substrate bag 2, pocket section 3) is aligned with the contour lines, the thick substrate bag 2 will block soil and sand washed away from the mountain side, forming a berm. This berm effect could make it easier for drifting plants to establish themselves on the berm. However, if the backing tissue 6 that forms the upper side of the pocket section 3 and the fronting tissue 5 that forms the lower side are designed to provide a relatively greater degree of floating (ease of deformation) when the substrate bag 2 is placed in the pocket section 3 than the former, meaning that the upper side of the pocket section 3 is less susceptible to deformation than the lower side, deformation of the weed control sheet 1 due to the thickness of the substrate bag 2 will be more noticeable on the underside and less noticeable on the upper side. As a result, the formation of the berm is less likely, which will more easily hinder the establishment and growth of drifting plants and facilitate the growth of target species.

In addition, as can be seen from Figures 1(A) and 2(A), the dense portion 7, which functions as a roof as described above, has a gentle slope and is particularly likely to block runoff sediment. However, in this example, the density of the constituent materials (warp and weft threads) is higher and the mesh size is smaller than that of the sparse portion 8. If the dense portion 7 is made of a material that has low friction with runoff sediment (such as the polyethylene used in the so-called blue tarps mentioned above), runoff sediment will not easily get caught on the dense portion 7 and will be able to flow down over it, meaning that the dense portion 7 also prevents the formation of berms. On the other hand, the sparse portion 8 has a steep slope and is particularly unlikely to block runoff sediment. In addition, the weft threads 6C extending in the Y direction in this sparse portion 8 are thin, so runoff sediment will not easily get caught on the sparse portion 8 either, meaning that the sparse portion 8 also prevents the formation of berms.

The present invention is not limited to the above-described embodiment, and can of course be modified in various ways without departing from the spirit of the present invention. For example, the following modifications can be mentioned:

In the example shown in Figures 1(A) and (B), three pockets 3 are provided in one double weed control sheet 1, but the number of pockets 3 can be changed as desired. Furthermore, the number of substrate bags 2 housed in each pocket 3 is not limited to one, and may be two or more.

In the examples of Figures 3 (D) and (E), sparse regions 8, 9 are formed in parts of the double weed control sheet 1 by using warp threads 6C that are thinner than in other areas and by increasing the pitch of the weft threads 6C, 5B. However, this is not limiting, and sparse regions 8, 9 may also be formed by other methods, such as by cutting slits in parts of the double weed control sheet 1.

In the above embodiment, the base material bag 2 can be inserted and removed from the pocket portion 3 from either one end or the other end, but this is not limited to this. For example, the base material bag 2 may be inserted and removed from the pocket portion 3 from only one end or the other end. In any case, at least one of the ends of the pocket portion 3 in the Y direction must be open.

In contrast, both ends of the weed control section 4 in the Y direction may be closed or open. For example, from the perspective of reliably preventing a substrate bag 2 intended for insertion into the pocket section 3 from being mistakenly inserted into the weed control section 4, it is preferable to close both ends of the weed control section 4 in the Y direction. However, from the perspective of being able to insert, for example, a material with water-retaining properties between the two upper and lower layers (front tissue 5, back tissue 6) that make up the weed control section 4, it is preferable to leave at least one of the ends of the weed control section 4 in the Y direction open. Methods for closing the Y direction ends of the pocket section 3 and weed control section 4 include gluing, sewing, tying, etc. using appropriate materials and tools.

The dense portions 7 only need to have a higher weed-preventing function than the sparse portions 8, and may have a higher or lower weed-preventing function than the areas of the backing tissue 6 that form the weed-preventing section 4. Alternatively, the dense portions 7 may not be provided, and the areas of the backing tissue 6 that form the pocket sections 3 may all be configured as sparse portions 8.

In the above embodiment, the dense portions 7 are provided near one end in the X direction of the region that forms the pocket portion 3 of the backing weave 6, and the sparse portions 8 are provided near the other end. However, this is not limited to this. For example, dense portions 7 may be provided at both ends in the X direction of the region that forms the pocket portion 3 of the backing weave 6, and sparse portions 8 may be provided between them. Alternatively, dense portions 7 and sparse portions 8 may be provided alternately from one end in the X direction to the other end in the region that forms the pocket portion 3 of the backing weave 6.

Instead of weft thread 6C, weft thread 6B may be placed in sparse portion 8, and in place of weft thread 5B, a thinner weft thread may be placed in sparse portion 9, or no weft threads may be placed in sparse portions 8, 9. However, if no weft threads are placed in sparse portions 8, 9, the warp threads 5A, 6A that are not entangled with the weft threads tend to flutter, which may get in the way when inserting the base material bag 2 into the pocket portion 3. Therefore, it is preferable to place weft threads in order to suppress the movement of warp threads 5A, 6A and make it easier to insert the base material bag 2 into the pocket portion 3.

In the above embodiment, the front and back weed structures 5 and 6 are woven so that they are switched between the top and bottom of the pocket section 3 and the weed control section 4, but this is not limiting. For example, two sheets may be stacked one on top of the other and joined together at appropriate locations by sewing, gluing, etc. to form the pocket section 3 (including the dense section 7 and the sparse sections 8 and 9) and the weed control section 4, which can be used as the double weed control sheet 1. In this case, it is possible to color the top surface of the pocket section 3 white and the top surface of the weed control section 4 dark by applying or spraying an appropriate paint.

In the above embodiment, a double weed control sheet 1 is used as an example of a multi-layer weed control sheet. The double weed control sheet 1 is made of a woven fabric with a two-layer sheet structure, in which a front weed layer 5 and a back weed layer 6 are laminated together. However, this is not limited to this. For example, a multi-layer weed control sheet made of a woven fabric with a multi-layer sheet structure in which three or more weed layers are laminated together, or a multi-layer weed control sheet in which three or more sheets are stacked one on top of the other and appropriately joined together, may also be used. When using such a multi-layer weed control sheet with three or more layers, the number of layers located above the substrate bag 2 when it is placed in the pocket portion 3 may be more or less than the number of layers located below the substrate bag 2, or the number of layers may be the same. However, when there are multiple layers located above the substrate bag 2, it is preferable to appropriately adjust the density of the area of each layer corresponding to the sparse portion 8 so that sparse portion 8 is formed even when the multiple layers are stacked one above the other. Similarly, when there are multiple layers located below the substrate bag 2, it is preferable to appropriately configure each layer so that sparse portion 9 is formed.

It goes without saying that the above modifications may be combined as appropriate.

REFERENCE SIGNS LIST 1 double weed control sheet 2 base bag 3 pocket section 4 weed control section 5 front structure 5A warp threads 5B weft threads 6 back structure 6A warp threads 6B weft threads 6C weft threads 7 dense section 8 sparse section 9 sparse section N slope S weed control greening sheet

Claims (3)

The multi-layer weed control sheet is equipped with a striped base material bag ,
A weed-control greening sheet characterized in that in the multi-layer weed-control sheet, at least the upper surface of the sparse portion arranged above the base material bag is whitish, and at least the upper surface of the weed-control portion located away from the upper side of the base material bag is dark-colored . The multi-layer weed control sheet has sparse and dense sections arranged on the upper side of the substrate bag, which is installed so that its longitudinal direction follows the contour lines of the slope , and the sparse sections are located closer to the foot of the slope than the dense sections . The multi-layer weed control sheet has pockets for accommodating substrate bags and weed control sections arranged alternately from one end to the other end,
The multi-layer weed control sheet is a double layer weed control sheet consisting of two layers, a front layer and a back layer,
The surface tissue is located on the upper side in the weed-preventing area and on the lower side in the pocket area.
The backing is located on the bottom in the weed-control area and on the top in the pocket area.
In the surface structure, the entire area that makes up the pocket part is a sparse area with a lower density and larger mesh size than the area that makes up the weed-control part.
In the backing structure, the area constituting the pocket part is divided into a sparse part having a lower density of constituent material and a larger mesh size than the area constituting the weed-control part, and a dense part having a higher density and a smaller mesh size than the sparse part.
3. The weed-control and greening sheet according to claim 1 , wherein the surface structure is made of a dark-colored material and the back structure is made of a white-colored material .