JPH0833406A - Natural lawn sheet structure - Google Patents

Abstract

PURPOSE:To provide a natural lawn sheet structure capable of readily growing or maintaining lawns, excellent in stability in an established state and strength, and durable even in the case it is used for a sport facility. CONSTITUTION:This natural lawn sheet structure is composed of a base web layer 1 having water retention properties and capable of controlling the amount of retained water, a core layer 2 made of a net material, a lawn seed keeping sheet 3 for keeping lawn seeds 32 and germinating them and a lawn seed- protecting web layer 4 which does not obstruct germination of the lawn seeds and growth of the germinated lawn seedlings, putting in layers in this order from bottom to top. Pile yarns 5 are interwoven thereinto from the base web layer 1 to the lawn seed protecting web layer 4 so that lawn-protecting loop piles 51 may be formed on the surface of the lawn seed-protecting web layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a natural turf sheet structure which can be used by laying it on the field, floor or the like of various sports facilities.

[0002]

2. Description of the Related Art Taking a sports facility as an example, natural grass and soil have been used for a long time in the field, but since these are difficult to maintain and manage, artificial grass is often used today. It is like this. However, some sports include those that are not suitable for playing on artificial grass, such as soccer, so natural grass is still used for such competitions.

In the case of indoor sports facilities, however, it is difficult to grow natural grass in the facility, so natural grass that has been separately grown is temporarily installed on a floor material such as artificial grass. Also, if the turf installed is damaged, that part is replaced with a new one. Even in outdoor sports facilities, it is difficult to grow and maintain natural grass if it is grown directly on natural soil, and when grass is damaged due to competition play, it takes time to regenerate it. However, since it may not be possible to continuously use the natural grass that has been separately grown on artificial grass, if damage occurs, that part may be replaced with a new one.

[0004] As described above, natural turf for installation in a sports facility or for replacing a part of the turf installed in the facility when the damage occurs, natural turf grown separately in natural soil is cut into an appropriate size. Of course, a natural turf sheet structure that can be relocated without directly using natural soil may be adopted.

As a natural turf sheet structure, for example, Japanese Patent Laid-Open No. 51-119108 discloses a roll-wound in which a reticulated mat and an impermeable underlay sheet are sequentially provided under a lawn soil layer composed of sawdust compost. Japanese Laid-Open Patent Publication No. 54-117732 discloses a lawn mat of No. 60-95004, which has a perforated rubber mat or a lawn sheet on which soil or sand is placed on a net and a lawn is grown on the net. Japanese Patent Laid-Open No. 62-25907 discloses a synthetic resin plate which is laid in a place for growing natural grass, and in which soil and sand, a lawn runner, a chemical fertilizer and a water retaining material are put in the hole to grow grass. However, a seeded mat obtained by mixing and holding a turf seed in a mat containing rock wool as a main component is disclosed in JP-A-63-910.
Japanese Patent Laid-Open No. 2-10 discloses a vegetation mat in which rock wool is integrated with aggregates having tip portions at substantially equal intervals and bottom portions formed in a lattice shape, and turf seeds are enclosed in low wool.
Japanese Patent No. 4216 discloses a long winding roll product in which cut grass is decomposed and stretched, streak-like runners are arranged on a net having an appropriate mesh interval, and the upper surface thereof is covered with water-soluble paper. Japanese Patent No. 247204 discloses that a side sheet and a lower surface of a turf growing floor material obtained by mixing a fertilizer and an inorganic lightweight soil member are wrapped with a lower sheet, an upper sheet is provided on an upper surface of the floor material, and a turf is provided on a lower surface side of the upper sheet. A natural turf in which a seed holding member is arranged, a mesh-like wavy net is provided in the floor material between the turf seed holding member and the lower sheet, and the upper and lower sheets are interconnected by sewing threads, staples and the like. Each floor is disclosed.

[0006]

The natural grass sheet structure disclosed in the above publication is cut as it is or cut as needed, or after germination of grass seeds, and further after growth, cut to an appropriate size if necessary. , Home garden, river dike, park,
It can be laid and used on the soil of golf courses and in the planting zone of various structures. Similarly, sports facilities are not unavailable, but they have the following problems.

That is, Japanese Unexamined Patent Application Publication No. 60-9
The perforated rubber mat and synthetic resin plate described in Japanese Patent Publication No. 5004 are for growing grass not intermittently but intermittently, and therefore it is difficult to adopt it when it is desired to grow grass entirely. Especially difficult to use in sports facilities. In addition, JP-A-3-24
Except for the natural turf floor described in Japanese Patent No. 7204, in which the upper and lower sheets are connected and integrated with sewing threads, staples, etc., the other things are easily disassembled and damaged easily, and are severe in sports facilities. It is difficult to use in places where force is applied. Also, when the grass is damaged by being scraped or the like, the material under it appears and becomes very unsightly.

Even in the case of the natural turf floor disclosed in Japanese Patent Laid-Open No. 3-247204, if the turf is damaged such as being scraped, the material below appears similarly and becomes unsightly. In addition, the natural grass sheet structures described in any of the publications are not suitable for installation, such as being lightweight, and are particularly unsuitable for being installed in sports facilities and playing on them.

Therefore, an object of the present invention is to provide the following natural grass sheet structure. That is, in the state before the germination of the turf seeds, cut as it is or if necessary to an appropriate size, or after germination of the turf seeds or after the growth of the turf as it is or if necessary, in a garden or park of a general household. Even if there are natural grass sheet structures and weed seeds that can be easily and easily relocated to soil such as river dikes, golf courses, planting zones of various buildings, and sports facilities, press them down. It is possible to suppress weed growth by laying it, and it is easy to control water supply and nutrient supply to the turf, which is the whole of the natural turf sheet structure that is easy to manage turf growth and maintenance after turf growth. It is integrated and difficult to disassemble, and the grass seeds, sprouts, grass roots, etc. are protected against the load from above and the hanging load from the side, so that it can withstand use in sports facilities, Also, this Turf training from the Luo point,
Natural grass sheet structure that is easy to maintain and manage after growth, natural grass sheet structure that can reduce unsightness compared to conventional natural grass sheet structures even when grass is damaged due to scraping, etc. Natural grass that can be made lighter to facilitate relocation, and can be made heavier to increase the stability of installation at the target location, and can be installed stable enough to be used in sports facilities, etc. Sheet structure, a natural turf sheet structure that can be produced as a long product.

[0010]

A natural turf sheet structure of the present invention for solving the above-mentioned problems has a water-retaining property and a base web layer, a net core layer, and a turf seed that can adjust the water retention amount. The turf seed holding sheet for germinating the seeds, and the turf seed protective web layers that do not prevent germination and subsequent growth of the turf seeds are stacked in this order from bottom to top, and the piles extend from the base web layer to the turf seed protective web layer. A turf protective loop pile is formed on the surface of the turf seed protective web layer by weaving threads.

The "turf seeds" in the turf seed holding sheet in the natural turf sheet structure of the present invention include not only turf seeds themselves, but also runners obtained from cut turf and the like that can be turf seeds. It is a concept that includes. Such a natural grass sheet structure has a base web layer, a base web layer, for easy transportation and storage.
The net core layer, the turf seed holding sheet, and the turf seed protective web layer may be flexible so that they can be wound in a roll shape.

The base web layer should be water-retentive and capable of adjusting the amount of water retention. Regarding the water retention, it is sufficient if it can absorb and retain water by pouring water, pouring it, or immersing it in water. With regard to the above, it suffices if the water can be drained by compressing, squeezing, tilting or the like. In any case, it is desirable to have flexibility in order to improve familiarity with the place where the natural grass sheet structure is installed.

As such a base web layer, for example, a web layer made of cotton, a woven fabric of various fibers, a knitted fabric, a web layer made of a combination thereof and the like can be considered. Among these, the cotton web layer has good water absorption and water retention, and can easily discharge water by compressing, squeezing, etc., and the weight of the cotton web can be easily adjusted by adjusting the water retention amount. It is desirable because the amount of water supplied to sprouts, growing turf, etc. can be easily controlled, and the amount of nutrient supply can be controlled by making the retained water contain nutrients.

When the base web layer is a cotton web layer, the cotton may be natural cotton or synthetic fiber cotton.
A combination of these may be used, but it is also conceivable that all or part of the cotton is water-absorbent cotton made of water-absorbent fiber so that the water retention amount can be adjusted over a wide range. For example, it is possible to use a mixed cotton of synthetic fiber cotton and water absorbent cotton. Examples of the synthetic fiber cotton include cotton made of polyester fiber, acrylic fiber or the like having a denier of about 2 to 8, and as the water absorbent cotton, super absorbent fiber (trade name: Lanseal F) manufactured by Toyobo Co., Ltd. An example of the absorbent cotton is

The turf seed protective web layer does not prevent germination and subsequent growth of turf seeds in the turf seed holding sheet and may be any as long as it can protect the seeds. Is desirable. Furthermore, it is desirable that the water retention amount can be adjusted. From this point of view, also for this web, for example, a web layer made of cotton, a woven fabric of various fibers, a knitted fabric, a combination of these, and the like are conceivable. Of these, the cotton web layer is one of the desirable ones because it has good water absorption and water retention properties and can contribute to facilitating the control of the amount of water supplied to grass seeds and the like, and the amount of nutrient replenishment. When a cotton web layer is adopted, the cotton may be natural cotton, synthetic fiber cotton, or a combination thereof. Furthermore, as in the case of the base web layer, a part or all of it may be made of a water-absorbent fiber (for example, as described above). It is conceivable to use water absorbent cotton made of Lanseal F).

When a cotton web layer is used as each of the base web layer and the grass seed protection web layer, the grass seed protection web layer has a smaller amount of cotton than that of the base web layer and is thinner than the base web layer. Care should be taken not to hinder the germination of turf seeds and their subsequent growth. On the other hand, the thickness of the base web layer is adjusted so that the weight of the base web layer can be adjusted and the amount of water supplied to the turf can be controlled within a desired range.

The base web layer and the turf seed protection web layer may be interconnected by threads or other means. In this respect, the base web layer and the turf seed protection web layer made of cotton are:
A part of the cotton fibers constituting them may be entwined with each other through the net core layer and the grass seed holding sheet to be connected to each other. The connection of these two cotton webs, with the net core layer and the grass seed holding sheet sandwiched between them,
For example, it can be performed by carrying out a needle punching method generally known as a web joining method.

The pile yarns woven over the base web layer and the grass seed protection web layer in the natural grass sheet structure of the present invention contribute to the interconnection of both webs. Such pile yarn contributes to the integration of the natural grass sheet structure of the present invention, and the grass protection loop pile formed on the surface of the grass seed protection web layer by the pile yarn can protect grass seeds, shoots, roots, etc. It only needs to have a certain degree of tensile strength and waist strength, and examples of such pile yarns include thick denier filament yarns of polyamide, polypropylene, polyester and the like.

The height of the loop pile is from 3 to 3 for the purpose of protecting the above-mentioned turf species and so that the grown natural turf extends above the loop pile to exert its advantages.
It is considered to be about 15 mm, more preferably about 5 to 7 mm. The density of the loop pile on the surface of the lawn seed protective web layer can be appropriately selected within a range where the above-mentioned lawn seeds can be protected and growth of the lawn is not hindered.

Further, the pile yarns may be colored (typically green) so that even if the grown grass is damaged due to scraping or the like and the loop pile appears, it is not so unsightly. The turf seed holding sheet may be any sheet as long as it can hold the turf seeds while preventing them from migrating and germinate, but it is desirable that the turf seeds are dispersed as uniformly as possible.
As such a sheet, for example, germination of turf seeds, a nonwoven sheet that does not hinder the subsequent growth, turf seeds evenly distributed on the nonwoven sheet, and germination of turf seeds coated from above the turf seeds. , Which include a water-soluble turf seed pressing film that does not hinder the subsequent growth. The water-soluble turf seed control film may be a water-soluble film such as a protein-based or starch-based film, and may include germination nutrients.
In addition, it is also conceivable that seeds are dispersed and arranged on a base sheet such as a nonwoven fabric sheet, and the seeds are attached to the base sheet with an appropriate adhesive. In any case, it is desirable that each part except the seed is flexible so that it is well adapted to the net core layer and the lawn seed protective web layer.

The net core layer ensures air permeability to the grass roots,
Any material can be used as long as it protects the grass roots and plays a role of maintaining the strength of the natural grass sheet structure. For example, a three-dimensional mesh structure formed by intertwining synthetic resin fibers, a net plate 1 made of synthetic resin fibers, etc. A sheet, or a stack of multiple sheets,
A box-like net-cage-like object is considered. In any case, it is desirable that the natural turf sheet structure has flexibility as a whole in order to better fit the installation place of the natural turf sheet structure, or further, walking on the natural turf sheet structure or sports play. It is desirable to have appropriate elasticity in order to improve the feel.

From the viewpoint of flexibility, elasticity, a large number of voids, strength, etc., synthetic resin fibers having a diameter of 0.1 to 0.8 mm and made of, for example, polyamide, polypropylene, vinyl chloride resin, etc. are entangled. The three-dimensional network structure formed as described above is one of the preferable ones. As such a three-dimensional mesh structure, for example, a mesh structure manufactured by Zeon Kasei Co., Ltd. (trade name: Zeomat 7020) can be adopted.

[0023]

The natural turf sheet structure according to the present invention is cut into appropriate dimensions as necessary in the state before germination of turf seeds, or after germination of turf seeds or further growth of turf, if necessary,
It is easily and easily moved to the target field of natural turf such as the field or floor of a sports facility, where it is laid and used. When arranging multiple pieces of appropriate size side by side, if necessary,
Adjacent ones can be integrated with each other by sewing with a sewing machine. This integration provides installation stability.

The natural turf sheet structure according to the present invention can be supplied with water or water containing turf growth nutrients under suitable temperature conditions to provide a base web layer or a turf seed protection web. The layer absorbs and retains water, and the grass seeds germinate and grow into natural grass. Plural pieces of appropriate size, adjacent to each other,
In particular, when the base web layers having water-retaining property are placed side by side in contact with each other, the base web layer has a water flow path even when, for example, locally supplying water or water containing turf growing nutrients to the whole of them. The water and nutrients are supplied evenly throughout.

The roots of the grown turf reach the base web layer through the net core layer, and water is mainly supplied from here, or together with water, nutrients dissolved therein. The base web layer can be supplied with water to absorb water, retain water, or be compressed so as to be drained, whereby the weight can be adjusted. By adjusting the weight, the weight of the whole structure can be reduced, or the weight can be increased to increase the stability of the natural grass sheet structure at the installation place.

Further, the natural grass sheet structure according to the present invention is installed so that even when seeds of weeds are present at the place of installation, they are pressed down by the weight of the base web layer and other parts which are heavy due to water retention. This can prevent weeds from growing. In addition, since the whole is integrated, it is difficult to disassemble even if external force is applied, and the loop pile has a load from above on grass seeds, sprouts, grass roots, etc.
It protects against lateral pulling loads, etc., so it can withstand use even when laid in sports facilities.

Further, since the turf seeds and the like are protected by the loop pile in this way, also in this respect, turf growth and maintenance after growth are easy. Further, since the loop pile can be colored in a green color or the like, even if the grown natural grass may be partially scraped and lost due to proper coloring, the unsightly appearance can be reduced.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A natural grass sheet structure which is an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of the natural grass sheet structure before germination of turf seeds, and FIG. 2 is a schematic cross-sectional view of the natural grass sheet structure in a turf growth state. As shown in FIG. 1, this natural grass sheet structure includes a base web layer 1, a three-dimensional mesh structure 2 as an example of a net core layer, a grass seed holding sheet 3, and a grass seed protection web layer 4. In this order, from top to bottom, pile threads 5 are woven from the base web layer 1 to the turf seed protective web layer 4, and a large number of loop piles 51 are evenly erected on the surface of the turf seed protective web layer 4. Is.

The base web layer 1 is made by mixing 50% synthetic fiber cotton composed of 6 denier polyester fiber and 50% water absorbent cotton composed of 5 denier water-absorbing acrylic fiber (Lanseal F manufactured by Toyobo Co., Ltd.) to obtain a basis weight. The cotton web layer is 300 g / m ² , and the lawn seed protection web layer 4 is also a cotton web layer having a basis weight of 100 g / m ² by mixing the same 50% synthetic fiber cotton and 50% water absorbent cotton as in the web layer 1. .

These cotton web layers 1 and 4 were needling 50 times / cm by a needle punching method with the mesh structure 2 and the turf seed holding sheet 3 sandwiched between them.
These web layers 1, 4 are connected to each other by carrying out in step ^2.
Some of the cotton fibers constituting the above are entwined and connected to each other through the mesh structure 2 and the grass seed holding sheet 3. Three
The three-dimensional mesh structure 2 is Zeomat 70 manufactured by ZEON Corporation.
20 is made by intertwining polyamide (nylon) filaments having a diameter of 0.5 mm, and the weight per unit area is 420 g / m ² ,
It has a total thickness of 20 mm. It has irregularities on the upper and lower surfaces, has many voids, and is flexible and elastic.

The turf seed holding sheet 3 is made of flexible thin air-permeable material,
A turf seed 32 is uniformly dispersed and arranged on a water-resistant non-woven sheet 31, and a protein-based flexible water-soluble turf seed pressing film 33 is laminated thereon. There is no hindrance to the training. In addition,
The turf seed 32 is a turf seed here, but may be a runner obtained from cut grass or the like.

The pile yarn 5 is 3000d / 39f (d:
Denier, f: filament) polyamide bulk-processed long fiber (BCF nylon yarn), colored in green, and woven with 5/16 inch gauge and 4 stitches. The height of the grass protection loop pile 51 formed on the surface of the grass seed protection web layer 4 is about 5 to 6 mm. The natural grass sheet structure described above is mass-produced in a long product at the factory. Therefore, in use, it is cut into an appropriate size. Then, before the germination of the turf seed 32, after germinating the turf seed, or even after turf growth, it is easily and easily transferred to a natural turf installation target place such as a field or floor of a sports facility, and laid and used there. To be done.

When a plurality of pieces of appropriate size are arranged side by side, if necessary, adjacent pieces may be connected to each other by sewing with a sewing machine or the like to be integrated. This integration brings about installation stability and is preferable in sports facilities and the like. When the natural grass sheet structure shown in FIG. 1 is supplied with water or water containing grass growing nutrients, the base web layer 1 and the grass seed protection web layer 4 absorb and retain water, and the grass seeds 32 germinate. Then
As shown in FIG. 2, it grows into natural grass 30.

The roots 301 of the growing grass 30 are grass seed holding sheets 3
The non-woven fabric sheet 31 and the three-dimensional mesh structure 2 reach the base web layer 1 to reach the base web layer 1, from which water or further water and nutrients dissolved therein are supplied. Since the base web layer 1 can be supplied with water to absorb water, retain water, or be compressed to be drained, the amount of water retention can be easily adjusted. By adjusting the amount of water retention, the turf portion can be adjusted. It is possible to easily control the water supply to the water, or the water supply and the nutrient supply together with the water supply. Therefore, the turf growth management and the maintenance management after the growth can be easily performed.

When a plurality of sheets of appropriate size are placed side by side with adjacent ones in contact with each other, especially the water-retaining base web layers 1, water or turf growth nutrients are locally applied to the whole of them. Even when supplying the impregnated water,
The base web layer 1 plays a role of a water flow path, and water and nutrients are uniformly supplied as a whole. Therefore, also in this respect, it is easy to manage turf growth and maintenance after growth.

Further, since the natural grass sheet structure can be installed so that even when seeds of weeds are present at the place where the natural grass sheet structure is to be installed, the weeds are held down by the weight of the base web layer and other parts which have become heavy due to water retention. By suppressing the growth of weeds to that extent, it is possible to save the labor required for the treatment of weeds, and in this respect also, grass management and maintenance after growth are easy.

Further, the base web layer 1 can be adjusted in weight by adjusting the water retention amount thereof, and the grass seed protection web layer 4 can be adjusted in auxiliary weight by adjusting the water retention amount thereof like the base web layer 1. Even after germination, this weight adjustment can reduce the overall weight and facilitate relocation, or increase the weight to increase the installation stability at the natural turf sheet structure installation location. Even when installed in a place where intense force is applied by playing,
Installation stability that can withstand use is obtained.

Further, since the pile yarn 5 is woven as a whole and the base web layer 1 and the lawn seed protective web layer 4 are connected to each other by the entanglement of the constituent fibers, the whole is integrated. Therefore, even if an external force is applied, it is difficult to disassemble, and the loop pile 51 is turf seed 3
2. It has a protective effect against loads from above, such as sprouts and turf roots, and lateral loading loads, etc., so the turf seeds 32, sprouts, turf roots, etc. are less likely to be damaged, and even if laid in a sports facility. Can withstand use.

In addition, as described above, the grass type and the like are loop piles 5.
Since it is protected by No. 1, it is easy to grow grass and maintain it after growth. In addition, this loop pile 51
Also functions as a non-slip for pedestrians, sports players, etc. on the natural grass sheet structure. Further, since the loop pile 51 is colored in green, even if the grown natural grass 30 is partially scraped and lost, the green color of the loop pile 51 is similar to that of the surrounding grass 30. Appears, so the unsightlyness is reduced.

[0040]

As described above, according to the present invention, it is possible to provide a natural grass sheet structure having the following advantages. That is, in the state before the germination of turf seeds, cut as it is or if necessary, to an appropriate size, or after germination of turf seeds or after turf growth, cut as it is or if necessary, in a garden or park of a general household. It can be easily and easily relocated to river levees, soil such as golf courses, planting zones of various buildings, and sports facilities. Even if there are weed seeds, weeds can be laid down to suppress them and weeds can be prevented from growing, and by adjusting the water retention amount of the base web layer, it is possible to easily control the water supply to the grass and the supply of nutrients. Therefore, it is easy to manage the turf growth and the maintenance after the turf growth. It is integrated in the whole and difficult to disassemble, and it is also used in sports facilities because grass seeds, sprouts, grass roots, etc. are protected by a loop pile against the load from above and the pulling load from the side. Can also withstand
From these points as well, it is easy to grow grass and maintain it after growth. By appropriately coloring the loop pile such as green, even if the grass is damaged due to scraping or the like, the unsightly appearance can be reduced as compared with the conventional natural grass sheet structure. Weight can be adjusted by adjusting the water retention amount of the base web layer, which makes it easier to relocate by reducing the weight, or it can be weighted to increase the installation stability at the installation target position, and it can be used even in sports facilities etc. Installation stability can be obtained. It is possible to produce long products.

In addition to the above, when the natural grass sheet structure of the present invention is cut into an appropriate size or formed from the beginning to an appropriate size and a plurality of sheets are combined and laid side by side, adjacent ones are It can be easily joined by sewing with a sewing machine and the like, so that the installation stability can be obtained as a whole. When installing a plurality of sheets of appropriate size side by side with adjacent ones, in particular base water web layers having water-retaining property, side by side, water or water containing turf growth nutrients is locally applied to them. Even when it is supplied, the base web layer plays a role of a water flow path, and water and nutrients are uniformly supplied as a whole. Therefore, also in this respect, it is easy to manage turf growth and maintenance after growth.

Further, the base web layer and the lawn seed protection web layer are each made of cotton, and a part of the fibers constituting the both web layers are entwined and connected through the net core layer and the lawn seed holding sheet. If so, the whole is integrated and difficult to disassemble. Further, the base web layer and the turf seed protective web layer are each a web layer made of cotton, and when the cotton constituting at least the base web layer of the two web layers contains a water absorbent cotton made of water absorbent fiber, The water retention of the web layer, and hence the weight, can be adjusted in such a wide range.

When a three-dimensional mesh structure in which synthetic resin fibers are entangled with each other is used as the mesh core layer, the strength of the entire structure is maintained and the air permeability to the grass roots is sufficient. . Further, when the whole is flexible enough to be wound in a roll shape, it can be easily transported by being wound in a roll shape.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a natural grass sheet structure according to an embodiment of the present invention before sprouting seeds of turf.

FIG. 2 is a schematic cross-sectional view of a turf growth state of the embodiment shown in FIG.

[Explanation of symbols]

 1 Base Web Layer 2 3D Mesh Structure 3 Turf Seed Holding Sheet 31 Nonwoven Sheet 32 Turf Seed 33 Turf Seed Pressing Film 4 Turf Seed Protective Web Layer 5 Pile Thread 51 Loop Pile 30 Natural Turf 301 Turf Root

Claims (5)

[Claims] 1. A base web layer having water retention and an adjustable water retention amount, a net core layer, a grass seed holding sheet for holding and germinating grass seeds, and germination and subsequent growth of grass seeds. The grass seed protection web layers are stacked in this order from bottom to top, and pile yarns are woven from the base web layer to the grass seed protection web layer to form a grass protection loop pile on the surface of the grass seed protection web layer. Natural turf sheet structure characterized by being 2. The base web layer and the lawn seed protective web layer are web layers each made of cotton, and at least the cotton constituting the base web layer of both web layers contains water absorbent cotton made of water-absorbent fibers. 2. The natural grass sheet structure according to claim 1, wherein a part of the cotton fibers constituting the web layers are entwined and connected to each other through the mesh core layer and the grass seed holding sheet. 3. The turf seed holding sheet is a non-woven sheet that does not prevent germination of turf seeds and subsequent growth, turf seeds uniformly distributed on the non-woven sheet, and is coated from above the turf seeds, The natural grass sheet structure according to claim 1 or 2, which contains a water-soluble grass seed presser film that does not prevent germination of grass seeds and subsequent growth. 4. The three-dimensional mesh structure body in which synthetic resin fibers are entangled with each other, wherein the mesh core layer is formed of a three-dimensional mesh structure.
The natural grass sheet structure according to 2 or 3. 5. The natural grass sheet structure according to claim 1, 2, 3 or 4, which is flexible enough to be wound into a roll.