JPH08205748A - Weed preventive bag and its use - Google Patents

Abstract

PURPOSE: To assist sound growing of afforested trees by filling a forest land herbicide and a soil or a high polymeric water absorbing resin or a mixture thereof in a bag comprising a biodegradable material, applying it around the afforested trees when weeding and weed prevention are needed in an afforested area, killing weeds and miscellaneous trees for a predetermined period, decomposing and extinguishing the bag in the soil when it is not needed and reducing it to the soil. CONSTITUTION: This weed preventive bag is prepared by filling a mixture containing a forest land herbicide 5, a soil 6 and a water holding agent into a bag 4 comprising a biodegradable material and sealing them. By applying one or more of the weed preventive bags around an afforested tree, weeding and/or weed preventive effects can be kept for a long time (slow release) and environmental problems and sanitary troubles of workmen are hardly caused, as the herbicide is difficult to flow out by rainwater.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weed-proof bag useful for weeding a plant in a plantation and a method of using the bag. More specifically, the present invention relates to a weed-preventing bag that retains the herbicidal and inhibitory functions of a forest herbicide for a long period of time and has few problems such as environmental pollution, and a method for using the bag.

[0002]

2. Description of the Related Art In the field of forestry, after planting afforestation trees, weeds grow around the afforestation trees, and their growth is significantly hindered. Therefore, it is necessary to mow the weeds around the planted trees, and usually it is necessary to mow the weeds twice a year from spring to summer every several years after planting.

The most important purpose of weeding is to prevent growth inhibition of afforestation trees caused by pressure of cypress plants and promote healthy growth of afforestation trees. When cypress plants grow around the planted trees, the nutrients and water in the soil necessary for the growth of the planted trees are significantly deprived, which impairs the absorption of nutrients and water in the planted trees, resulting in poor root system and foliage development. And the growth of planted trees is significantly reduced. Therefore, it is necessary to mow the weeds until the planted trees planted in the planted area reach a certain height.

[0004] This method of cutting down is to mow all the weeds and trees that obstruct the afforestation tree over the entire afforestation area, to remove the weeds along the planting line of the afforestation tree, and around the afforestation tree. There is a method such as pruning in which only the chisel is cut into a circle or a square, and the undercut work is performed by using an undercut sickle or a brush cutter.

However, the use of the undercrop hand scythe is due to lack of labor and aging, and the use of the engine type brush cutter causes the user to experience vibration disturbance. Is getting harder.

In recent years, it has been extremely difficult to secure a labor force in forestry, but it is expected that it will become more difficult in the future.

[0007]

As described above, the weeding work, which requires a large amount of labor intensively in the shortest time in the afforestation work, makes the various functions of the forest work most effectively. , It is an important nursery work for the individual forest trees that form the basis of forests to grow healthier and more efficiently.

[0008] However, there is a problem that the number of people engaged in such work is decreasing due to lack of labor force, aging, and severe work in hot summer weather. Against this background, the number of afforested areas where weeding work has not been properly carried out is increasing. Therefore, using forest land herbicides for weeding work is a very effective method as a low-cost labor-saving means. However, simply sprinkling the herbicide is likely to cause runoff due to rainwater, etc. in the forest land on the slope, and the herbicidal and / or weed-controlling effect will not last for a long time. However, there was a problem that it mixed with water and waterworks and caused environmental problems. There was also a problem of hygiene for forestry workers who handle high concentrations of herbicides.

In order to solve the above-mentioned problems of the prior art, the present invention has a long-lasting herbicidal and / or herbicidal effect, prevents herbicide from flowing out even in rainwater, etc. An object of the present invention is to provide a weed-proof bag which is hard to cause and a method of using the same.

[0010]

In order to achieve the above object, the weed-preventing bag of the present invention is a mixture of a bag-like material made of a biodegradable material capable of being decomposed or decomposed by soil microorganisms and containing at least a herbicide. It is equipped with a structure in which

In the above-mentioned constitution, the bag-like material is made of at least one selected from the group consisting of cellulosic fibers such as vegetable fiber, regenerated fiber and semi-synthetic fiber, and the cloth is chemically bonded with the composite of fine cellulose and chitosan. It is preferably a composite fabric.

Further, in the above structure, it is preferable that the cloth is at least one selected from a non-woven fabric, a woven fabric, and a knitted bag. Moreover, in the said structure, it is preferable that the herbicide is mixed with at least 1 material selected from soil, a water retention material, a water absorption material, and a foaming material.

Next, the method of using the weed-preventing bag of the present invention is to use a bag-like product made of a biodegradable material which can be decomposed or decomposed by soil microorganisms and filled with a mixture containing at least a herbicide. It is characterized by arranging one or more trees around afforested trees in afforested areas to weed and / or prevent weeds.

[0014]

According to the structure of the weed-preventing bag of the present invention, since the bag-like material made of a biodegradable material capable of being decomposed or decomposed by soil microorganisms is filled with the admixture containing at least a herbicide, the herbicidal and It is possible to provide a weed-preventing bag in which the weed-preventing effect lasts for a long time (slow-release property), the herbicide does not easily flow out even by rainwater, and environmental problems and worker hygiene problems do not occur.

Further, the bag-like material is a composite cloth in which a cloth formed of at least one selected from cellulosic fibers such as plant fibers, regenerated fibers and semi-synthetic fibers is chemically bonded with a composite of fine cellulose and chitosan. According to the preferred configuration of the present invention, the bag-shaped bag main body is prevented by soil microorganisms at the time when the weeds that inhibit the growth of the afforested trees for a predetermined period of time are suppressed and their regeneration is prevented, and the suppression of the weeds is no longer required. It decomposes and decomposes into soil. As described above, the weed control bag for forestry can assist the sound growth of the planted tree.

Further, according to the preferable constitution of the present invention in which the cloth is at least one selected from a non-woven fabric, a woven fabric and a knitted bag-like material, the cloth has high strength and appropriate moisture absorbability and breathability. Therefore, sustained release of the herbicide can be sustained. Nonwoven fabrics are particularly preferable because they are inexpensive to manufacture.

Further, according to the preferable constitution of the present invention in which the herbicide is mixed with at least one material selected from the soil water-retaining material, the water-absorbing material and the foaming material, the herbicide is gradually added by water. It can be dissolved and sustained release can be sustained.

Next, according to the constitution of the weed-proof bag of the present invention,
A bag-like material made of a biodegradable material that can be decomposed or decomposed by soil microorganisms is filled with an admixture containing at least a herbicide and enclosed, and one or more herbicide bags are placed around the afforested trees in the afforestation area to control herbicides and / or Alternatively, by controlling weeds, weeds that hinder the growth of forest plantation trees for a certain period of time are prevented and their regeneration is prevented, and the bag-shaped bag body is rotted by soil microorganisms at the time when it is no longer necessary to control the weeds. It decomposes and is returned to the soil, which can support the healthy growth of planted trees.

[0019]

The present invention will be described more specifically with reference to the following examples. The present invention, in order to effectively exert the herbicidal function of a forest herbicide, is decomposed by various soil microorganisms living in afforestation land, and is a bag-like material made of a material, preferably a fiber web made of a cellulosic fiber. , Non-woven,
Knitting, woven fabric, etc. are chemically bonded with a composite of fine cellulose and chitosan to form a composite material, and a herbicide and soil or a water-absorbing material (water retention agent) are formed in a bag body that is formed into a bag by molding and processing. A weed-proof bag obtained by filling a foaming agent or a mixture thereof is obtained.

The bag-shaped bag body constituting the weed-proof bag according to the present invention comprises a cellulosic short fiber made of natural fibers such as hemp, cotton and pineapple veins, regenerated fibers such as rayon and cupra, and semisynthetic fibers such as acetate and triacetate. Fiber web composed of at least one kind of fiber or rayon filament non-woven fabric composed of regenerated fiber, or spun yarn formed of at least one kind of cellulosic fiber such as plant fiber, regenerated fiber, semi-synthetic fiber, or filament yarn Knit and woven cloth are used as materials. Nonwoven fabrics that can be used in the present invention include, for example, card non-woven fabrics, heat-bonded non-woven fabrics, needle punched non-woven fabrics, spunbonded non-woven fabrics, melt-blown non-woven fabrics, and the like, and the structure of the woven fabric or knitted fabric is not limited.

As the binder for impregnating and binding the above materials, fine cellulose having an average diameter of 1 μm or less is preferably dissolved so that chitosan: organic acid (acetic acid, lactic acid, citric acid, etc.) = 1: 1. Concentration 0.1-2.0
Fine cellulose-containing chitosan salt aqueous solution mixed with wt% chitosan salt aqueous solution as a binder is soaked or sprinkled to adhere 0.5 to 10 parts (solid weight) to 100 parts (solid weight) of fiber, and dried and heated. To form a water-insoluble composite non-woven fabric or composite knitted fabric, which is used as a material for forming the bag body.

The preferred characteristics of the material for forming the bag body thus obtained are as follows. (1) Unit weight 20 to 500 g / m ² (2) Thickness 0.1 to 1.0 mm (3) Breathability 20 to 500 cm ³ / cm ² / sec (However, the measuring method is according to JIS-L-1096) (4 ) Strength 0.5 to 20 kg / 10 cm width Chitosan in the above binder has a deacetylation degree of 40.
-100% and a molecular weight of 2000-500000 are used, and the compounding ratio of chitosan and fine cellulose is 2:
It is preferably in the range of 8 to 4: 5.

The biodegradable composite non-woven fabric and the knitted fabric thus constructed are used as a material to form a bag body in a desired size by means such as wet heat molding, sewing or adhesive processing.
The bag is filled and filled with a mixture of powdery granular woodland herbicide and soil or a water absorbent material (water retention agent), for example, a polymer water absorbent resin or an inorganic water absorbent, or a mixture of a herbicide, soil and a water absorbent material. Form a weedproof bag.

The forestry weed control bag thus formed is used by laying it on afforestation land, and the active ingredient of the water-soluble powdery grain type forest land herbicide is eluted with time to kill weeds, Can be suppressed.

Further, after about 1 to several months after laying, it is completely decomposed and eliminated by microorganisms in the soil, so that it is not necessary to collect the main bag after the forest herbicide is dissolved, and an additional effect that does not leave contaminants can be obtained. Have.

The weed control bag for forestry according to the present invention can secure a relatively large labor force mainly during the off-season before the plants start to grow, for example, from early February to early March, or the main weeds to be weeded. Since the perennial herbs and woody plants that are trees grow using the stored nutrients of the previous year, we can surely lay the weed-proof bag in the afforestation area from the end of May to the end of June when the nutrients of the previous year are the smallest. , Weed trees should not be prosperous and should be laid around planted trees when it is possible to lay a weed control bag within the planted area.

After the laying, the surface of the weed-proof bag is warmed as the temperature rises when the weeds start to grow,
Soil filled in the bag body or water absorbent material (water retention agent)
Alternatively, the temperature in the mixture or the temperature of the covered soil surface increases due to the placement of the weed-proof bag, and the soil in the bag or the water-absorbing material (water retention agent) or the water in the soil under the bag increases It permeates from the grounded soil surface and slowly elutes the active ingredients of water-soluble herbicides into plantations.

The herbicide that can be used in the present invention may be of any type. In the case of Japan, preferable forest land herbicides include chlorate-based herbicides such as sodium chlorate and DP.
Examples thereof include halogenated fatty acid type herbicides such as A, tetrapion and TCA, carbamate type herbicides such as carbutyrate, and mixed agent type herbicides such as tetrapion + DPA and tetrapion + triclopyr.

In particular, in the case where the bag main body is mixed and filled with a polymeric water-absorbent resin (water-retaining agent) and a herbicide as the water-absorbent material, the polymeric water-absorbent resin (water-retaining agent) itself has its own weight due to the above-mentioned action. It absorbs hundreds of times more water and becomes a gel (agar-like). While retaining water remarkably, part of it penetrates from the soil surface that is in contact with the bag and slowly elutes the active ingredient of the herbicide. Furthermore, when the soil surface covered by the bag body is dried, the active ingredient of the water-soluble herbicide is slowly eluted along with the moisture absorbed and retained along with the surrounding soil drying. That is, when a polymer water-absorbent resin (water retention agent) is used as a filler for a weed control bag for forestry, by repeating the above-mentioned absorption-release cycle, the effectiveness of the herbicide on the weeds and trees in afforestation areas is improved. The components can be stably supplied.

Examples of such a polymer water-absorbent resin include crosslinked polyacrylate-based resins, starch-polyacrylate-based resins, polyvinyl alcohol (PVA) -polyacrylate-based resins and the like. Also, for example, starch-polyacrylate may be used as a water retention agent. In addition, a foaming agent can be used as a substance that reduces weight and adsorbs water. Such foaming agents include, for example, open-celled permiculite, pumice, silica, silica, and other inorganic or biodegradable plastic foams.

The weed-preventing bag thus obtained is used by placing one or more at the base of a tree planting tree such as cedar or cypress. Preferably, two or three pieces are laid on the upper side of the slope with a distance of about 20 to 30 cm. As another method of use, the bag body and herbicide are carried to the target afforestation area for weeding, and a predetermined amount of soil or polymer water-absorbent resin that acts as a bulking agent is mixed and filled locally. , The sealing port is glued with a double-sided tape and placed at the root of the planted tree.

The dissolved active ingredient of the forest herbicide is absorbed into the plant body mainly from the roots of the cypress plant that has just started to grow, and suppresses the growth of shoots and new leaves having weak resistance. Partly kills and suppresses the growth of cypress plants while killing some species of.

The forest herbicide at this time has a high selectivity for planting trees, suppresses the growth of weeds, and only kills some kinds of weeds, and thus the planting trees On the other hand, herbicide does not cause phytotoxicity.

An embodiment of the present invention will be described in detail below. Example 1 Viscose rayon fiber (fineness: 2 denier, fiber length:
38 mm) was formed using a known card machine and a web forming machine such as a cross wrapper or a land webber to form a cross web having a fiber areal weight (g / m ² ) of 100 g / m ² and a thickness of 0.2 mm.

This web is put on a needle punching machine to form 5
A needle punching treatment of 0 P / cm ² was performed to form a temporarily fixed punched web. Next, as an inter-fiber binder, for example, chitosan (molecular weight: 15,000, trade name: Flownac C;
Kyowa Yushi Kogyo Co., Ltd.): Lactic acid = 1: 1 (weight ratio) to prepare a chitosan salt aqueous solution having a concentration of 1% by weight, and separately pulped to make a diameter of 1 μm or less and a length of 200 to 700 μm.
1% by weight aqueous suspension of fine cellulose in the above chitosan salt aqueous solution, fine cellulose: chitosan salt = 70: 30
(Weight ratio) were mixed to prepare an aqueous solution of fine cellulose-chitosan salt having a concentration of 1%.

Using the above fine cellulose-chitosan salt aqueous solution as a binder, the temporary fixing cloth web is dipped and processed,
It was made to adhere so as to have a solid content of 2 g / m ^2, and dried at 100 ° C. for 5 minutes in a hot air dryer. This allows
An air-permeable, water-permeable biodegradable composite non-woven fabric was formed by fixing fine cellulose and chemical bonds between chitosan and the surface of the fiber where the fibers cross each other and contact each other. The air permeability of the obtained composite nonwoven fabric was 100 cm ³ / cm ² / sec (according to JIS-L-1096).

Next, as shown in FIG. 1, the microbial degradable nonwoven fabric 1 is cut into a predetermined size, for example, 20 cm × 40.
cm (width x length) is folded in two, and the fixing portion 2 is formed at two peripheral points indicated by the remaining dotted line by an adhesive means (eg, adhesive, adhesive tape, wet heat adhesive) or sewing, and a bag-shaped bag body Formed 3.

The material having the following composition was mixed and filled in the microbial-degradable non-woven bag thus formed and sealed. (1) Forest herbicide: 50 g of sodium chlorate (2) Polymeric water absorbent resin (water retention agent): Sunwet IM-510
0 (brand name) 10 g (3) Soil: 100 g of hemp soil Mixing the mixed agent type herbicide with soil or a water-absorbent resin, filling the bag body, and adhesively sealing the sealing opening to obtain a weed-proof bag. . A schematic cross-sectional view of the obtained weed-proof bag is shown in FIG. In FIG. 2, 2 is a fixed part, 4 is a bag-like bag, 5 is a forest herbicide, and 6 is soil. Figure 3 ~
It was laid like 4. In FIGS. 3 to 4, 11 and 12 are weed-proof bags, 13 is afforestation trees (eg cedar, cypress, etc.), 1
4 is an area where weeding and weeding can be prevented, 15 is the upper side of the slope,
16 is the root of afforestation tree, 17 is weeds (for example, bamboo grass, sushi,
Litter, broad-leaved trees and shrubs). Grass bag 11,
12 is 20 to 30c slightly above the slope from the root of the planted tree
It was laid at a distance of about m. The slope angle of the mountain is about 30 °
Met.

The active ingredient contained in the forest herbicide filled by laying gradually elutes with time due to moisture in the soil, rainwater, etc., and kills the weeds over a long period of about 6 months. , The suppression effect was demonstrated. In addition, by laying a weed control bag for forestry, the range in which the weeds and trees are killed and suppressed is the slope angle of the plantation, the number of bag bodies placed, the type of forest herbicide that is filled, and the filling of herbicide. Although there are differences depending on the amount, as a result of arranging 170 planted trees, a maximum of 80 cm in the upper direction of the slope, an average of 34 cm,
The maximum height was 88 cm in the downward direction of the slope, the average was 39 cm, the maximum length was 81 cm in the right side of the slope, the average was 39 cm, and the maximum length was 91 cm in the left side of the slope, and the average was 34 cm. In addition, the bag itself, which does not require the control of cypress plants, was decomposed and disappeared by soil microorganisms and could be returned to the soil.

The non-woven fabric constituting the bag body may be a short fiber non-woven fabric, a cellulosic rayon spunbonded non-woven fabric, or a rayon spunlaced non-woven fabric. In addition, by adjusting the content of an aliphatic compound or an aliphatic compound derivative as a water repellent to the fine cellulose-containing chitosan salt, the water content contained in the nonwoven fabric is adjusted, the active growth of microorganisms is suppressed, and the biodegradation rate is adjusted. It is possible to adjust the dismantling time up to several months.

Example 2 A plain weave cotton fabric formed by weaving 80 warps and wefts together with warp yarns and weft yarns of 26 count was dipped in the same fine cellulose-chitosan salt aqueous solution as in Example 1,
After adhering so as to have a solid content of 1 g / m ² , the same drying treatment was carried out to form a microbial degradable cotton woven fabric fixed by the complexation of fine cellulose-chitosan salt.

The plain woven fabric was cut in the same manner as in Example 1,
Forming a bag-shaped bag body, forest land herbicide and soil 100m
A mixture of 1 and 10 g of a polymer water-absorbent resin (starch-polyacrylate type) was filled, and the sealing opening was adhesively sealed to form a weed control bag for forestry.

When a plurality of the above weed-preventing bags were laid around the planted trees, the weeding trees were killed and suppressed as in Example 1, and the bag itself was completely decomposed and disappeared and returned to the soil.

As described above, according to the embodiment of the present invention, it is possible to extremely effectively carry out the low-cutting work of afforestation land as a means of thorough low cost and labor saving. In addition, when using the weeds, weeds that absorb the herbicide dissolved in rainwater etc. by laying a weed control bag around the forested trees, for example, above the forested trees on sloping land, prevent weeds from growing. Only useful trees can be killed, and useful weeds that play a role of ground cover for conserving the planted area other than the area around the planted trees can be left. Therefore, the soil and soil organic matter in the plantation area are effective for conservation of the plantation area, such as preventing the forestland from becoming excessively bare land due to rainfall, etc. Can also help.

Generally, in young plantations, the growth of cypress plants exceeds the growth of plantation trees. Therefore, the pressure of cypress plants often inhibits the growth of plantation trees. The weeds and trees reduce the soil temperature and temperature difference in the planted area day and night, soften the amount of solar radiation and wind speed on the surface, suppress the runoff of organic substances and topsoil on the surface due to rainfall, and prevent forest damage from large animals and pests. Plays a role to protect the direct and indirect. Therefore, it can be applied as a method of weeding work when it is necessary to protect afforested trees with weeds in afforested areas with poor topography and weather conditions.

In addition, the bag-shaped bag body can be decomposed into soil by soil microorganisms and returned to the soil at a time when it is not necessary to control the weeds and plants. The invention has various effects such as not being necessary.

If the flora (type) changes, the type and combination of herbicides may be changed as appropriate, and effective herbicides may be used. The type can be selected arbitrarily.

[0048]

As described above, according to the present invention, since a bag-like material made of a biodegradable material which can be decomposed or decomposed by soil microorganisms is filled with a mixture containing at least a herbicide, the herbicides and It is possible to provide a weed-preventing bag in which the weed-preventing effect lasts for a long time (slow-release property), the herbicide does not easily flow out even by rainwater, and environmental problems and worker hygiene problems do not occur.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a bag body used in the present invention.

FIG. 2 is a cross-sectional view of an embodiment of the forestry weed control bag of the present invention.

FIG. 3 is an explanatory view of an example in which the weed-preventing bag of the present invention is used for afforestation trees.

FIG. 4 is a sectional view of FIG.

[Explanation of symbols]

1 Microbiodegradable nonwoven fabric 2 Fixed part 3 Bag body 4 Bag-shaped bag 5 Forest herbicide 6 Soil or high polymer water absorbent resin (water retaining agent) or their mixture 11,12 Weed-proof bag 13 Forest trees (cedar, cypress, etc.) ) 14 Areas where weeding and weeding could be achieved 15 Upper side of slope 16 Roots of planted trees 17 Weeds (bamboo grass, plow, scraps, broadleaf shrubs, etc.)

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[Procedure amendment]

[Submission date] June 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

The material having the following composition was mixed and filled in the microbial-degradable non-woven bag thus formed and sealed. (1) Forest herbicide: 50 g of sodium chlorate (2) Polymeric water absorbent resin (water retention agent): Sunwet IM-510
0 (trade name) 10 g (3) Soil: Filling Ma Sa soil and by mixing the 100g the admixture herbicide such as soil or the water absorbent resin in the bag body, the weed bag by adhesive seal the filling port obtain. A schematic cross-sectional view of the obtained weed-proof bag is shown in FIG. In FIG. 2, 2 is a fixed part, 4 is a bag-like bag, 5 is a forest herbicide, and 6 is soil. Figure 3 ~
It was laid like 4. In FIGS. 3 to 4, 11 and 12 are weed-proof bags, 13 is afforestation trees (eg cedar, cypress, etc.), 1
4 is an area where weeding and weeding can be prevented, 15 is the upper side of the slope,
16 is the root of afforestation tree, 17 is weeds (for example, bamboo grass, sushi,
Litter, broad-leaved trees and shrubs). Grass bag 11,
12 is 20 to 30c slightly above the slope from the root of the planted tree
It was laid at a distance of about m. The slope angle of the mountain is about 30 °
Met.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Hosokawa 2-3-3 Hananomiyamachi, Takamatsu City, Kagawa Prefecture, Shikoku Institute of Industrial Technology, Industrial Technology Institute (72) Takamasa Kubo, Hanano, Takamatsu City, Kagawa Prefecture 2-3-3 Miyamachi, Shikoku Industrial Technology Laboratory, Institute of Industrial Technology (72) Inventor Yoshihara, 1st year 2-3-3 Hananomiyacho, Hananomachi, Takamatsu City, Kagawa Prefecture Shikoku Institute of Industrial Technology (72) ) Koichi Danbayashi 190-8 Kazawa, Yamazaki-cho, Shishiwa-gun, Hyogo Prefecture (72) Inventor Yutaka Yoshino 386-24 Mizoguchi, Koji-cho, Kanzaki-gun, Hyogo Prefecture (72) Shingo Taniguchi 950, Otsuki, Yamato-cho, Asago-gun, Hyogo Prefecture ) Inventor Mutsuo Nakagawa 1-21-15 Mefu, Takarazuka-shi, Hyogo Prefecture (72) Inventor Teruhiro Komatsu 2--4, Mukotoyo-cho, Amagasaki-shi, Hyogo Prefecture 50-306 (72) Inventor Sanzo Mimura, Hagino, Itami-shi, Hyogo Prefecture 4-chome 46-8

Claims (5)

[Claims] 1. A weed-preventing bag in which a bag-like material made of a biodegradable material that can be decomposed or decomposed by soil microorganisms is filled and sealed with a mixture containing at least a herbicide. 2. A composite fabric in which a bag-like material is formed by chemically bonding a fabric formed of at least one selected from cellulosic fibers such as plant fibers, regenerated fibers and semisynthetic fibers with a complex of fine cellulose and chitosan. The grass bag according to claim 1. 3. The weed-preventing bag according to claim 2, wherein the cloth is at least one selected from a non-woven fabric, a woven fabric, and a knitted bag. 4. The weed-preventing bag according to claim 2, wherein the herbicide is mixed with at least one material selected from soil, a water-retaining material, a water-absorbing material, and a foaming material. 5. One or more weed-preventing bags in which a bag-like material made of a biodegradable material capable of being decomposed or decomposed by soil microorganisms and filled with an admixture containing at least a herbicide are placed around a planted tree in a plantation area. A method of using a weed-proof bag, which comprises weeding and / or weeding.