JPH08154506A - Plant-growing sheet, vegetation using the same and plant growing machine. - Google Patents

Abstract

PURPOSE: To prepare a plant-growing sheet made of a cloth which permeates water vapor but not permeates water or an aqueous solution containing water- soluble salts, and can simply feed water obtained by desalting high-concentration aqueous salt solution to crop plants by only arranging the cloth on the water surface or the like, in no need of large-scale installation or execution. CONSTITUTION: This plant-growing sheet 1 is made of a cloth which permeates moisture but does not permeate water or an aqueous solution of water-soluble salts 6 and a plant-culturing layer 3 is layered on its upper face. Further, the sheet is arranged under or on the surface of the water containing water-soluble salts to inhibit the migration of the water-soluble salts to the water-absorbing roots of the growing plants. This cloth preferably has a water-resistant pressure higher than 1,200mm H2 O and a water vapor permeability of 5,000g/m<2> . 24 hours. It is preferred that this cloth is a nonwoven fabric made of ultrafine fibers having 20-200g/m<2> unit weight. Concretely, for example, the sheet 1 is floated on the water and the soil layer 3 for plant growth is placed on the sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for agricultural production and greening in which water containing water-soluble salts is used as feed water.

[0002]

2. Description of the Related Art Currently, one third of the world's agricultural yield
About 5.3% of the total farmland is irrigated farmland. In irrigated farmland in arid / semi-arid areas, water-soluble salts are contained in the soil in large amounts, resulting in rise in groundwater due to overirrigation and leakage from irrigation channels, and intense soil surface evaporation unique to arid areas. The accumulated salt accumulation is becoming latent. If you use water containing salt as irrigation water,
Accumulation of salt is promoted. Even in wet areas, it is a problem that always occurs in places with high groundwater levels where salty water invades from the surrounding area. Also, in places where horticultural agriculture has developed, as in Japan, as a result of the leaching of water-soluble salts from the soil being suppressed under rainfall interception and high fertilizer cultivation,
Soil salinization becomes a problem.

In such an irrigated farmland, it is essential to secure good quality irrigation water for sustainable agriculture.
We have made various efforts in areas that are not readily available.
For example, 1) a method of using river water, 2) a method of using groundwater, 3) a method of once refining high salinity water using solar heat or reverse osmosis membrane, and using the water for irrigation, etc. However, in 1), the water used upstream often returns to the original river again, and the water quality deteriorates in the downstream region. In 2), water is exhausted due to excessive pumping and water with high salt concentration. In 3), there is a concern that water pollution will occur due to the invasion of the facility, and enormous facility costs will be required to construct the facility.

[0004]

In order to carry out agricultural production, it is desirable to use water existing near the production area as a supply source. Further, it is more preferable that water, which is usually unsuitable for agricultural production, can be directly used because of its high salt concentration although it is abundant. If such water with high salinity, and eventually seawater, can be used directly, it is possible to expand agricultural production areas.

Therefore, an object of the present invention is to use high-salinity water existing in the immediate vicinity of the production area without effectively constructing a large-scale facility, and to effectively remove this salt to supply it to crops. However, it is to provide a method for vegetation such as crops at low cost.

[0006]

The present invention has the following constitution.

"When water-soluble salts are present in water or on the surface of water and a plant cultivation layer is provided, water vapor permeates, water or an aqueous solution of water-soluble salts does not substantially permeate, and water-soluble salts A plant-growing sheet characterized by comprising a fabric having a function of suppressing the movement of plants toward the water-absorption root side. ”A sheet that is permeable to water vapor and substantially impermeable to water is known as a so-called breathable waterproof sheet. belongs to. However, the present inventor, by arranging this sheet in water or on the surface of the water, from the high-salt water content, it is used as a sheet for supplying water containing no water-soluble salts to the plant cultivation layer, and the water supply seems insufficient. It was found that under the conditions described above, mulch is applied or it is used in combination with a water retaining material to enable plant growth in an environment in the presence of water with a high salinity, which cannot grow under normal conditions.

In the present invention, a cloth which is substantially impermeable to water or an aqueous solution of a water-soluble salt does not mean a cloth which is completely impermeable to an aqueous solution of water or a water-soluble salt, but has a water pressure resistance as described below. A fabric having a diameter of 500 mmH ₂ O or more. Such a fabric suppresses permeation of an aqueous solution in which water-soluble salts are dissolved under normal pressure, and thus the frequency of absorption of high-concentration salts directly into the water-absorbing roots of plants is reduced.

The form of the cloth in the present invention may be any of woven cloth, knitted cloth, non-woven cloth, synthetic paper, mat shape, felt shape and sheet shape. Further, it may have a single layer structure or a laminated structure, and can be manufactured by any known method. Examples of the woven fabric and knitted fabric include thin denier single yarns, fibrillated fibers, and high-density woven fabrics and high-density knitted fabrics. As the non-woven fabric, a non-woven fabric having an ultrafine fiber structure by a melt blow spinning method, a flash spinning method, an electrostatic spinning method, or the like, or a non-woven fabric made of a fiber obtained by stretching the above-mentioned ultrafine fiber by a known method, that is, a spunbonded nonwoven fabric , Needle-punched non-woven fabric, short fiber non-woven fabric, and the like. Examples of the material include polymeric materials such as polyethylene, polypropylene, polyamide, polyester, polyurethane, polycarbonate, and acrylic resin, but are not limited thereto. The synthetic paper, by using a synthetic polymer as a main raw material, by any known method, for example, a method of coating or surface-papering a film, or a method of making synthetic pulp such as vinylon or nylon and making it with a paper machine. Examples include manufactured products. Further, a material obtained by combining such a cloth with another cloth or a film, or a material subjected to a water repellent treatment is also preferably used. Examples of the film include a hydrophobic film having fine pores and a urethane-based non-porous film.

Various methods are adopted as the method for compositely integrating the cloth in the present invention with other cloths or films, and the method is not particularly limited. For example, joining by thermal action or adhesion by resin is used. Can be mentioned. Further, the obtained composite fabric may be partially bonded and adhered. For example, a thermal embossing method, an ultrasonic method, a high frequency method, etc. may be used as the thermal bonding method, and a dot coating method or a resin bonding method may be used. The streak coating method and the like are included. In addition, various physical properties described below can be adjusted depending on the size of the bonding / bonding area ratio.

In the present invention, a water repellent treatment may be applied to a cloth by an ordinary method. For example, a resin such as a silicone-based resin, a fluorine-based resin, a paraffin-based resin, an acrylic resin, or a wax-based resin may be directly applied to the cloth or the yarn Dipping, spraying,
It may be provided by padding or the like, and heat treatment may be performed if necessary.

The hydrophobic film having fine pores in the present invention can be produced by any known method. For example, there are porous films obtained by, for example, a method of forming holes in a film by electric discharge, a method of stretching a film containing a filler, a method of removing a filler from a film containing a filler, but the kind is not limited. .

The film material is not particularly limited, but a polyolefin resin film such as polyethylene or polypropylene or a fluorine resin film is usually preferably used. Specifically, although Celgard (manufactured by Daicel Chemical Industries, Ltd.) and Espoir (Mitsui Toatsu Chemicals, Inc.), which are made of polyolefin, are commercially available, they are not limited to these. Also, the pore size of the film is difficult to unconditionally define because the contact angle to water varies depending on the type of film material and the surface processing state, but it is sufficient if water vapor does not pass but water vapor does. , 0.01 to 100 μm, and more preferably those distributed in the range of 0.2 to 10 μm.

The physical properties of the cloth in the present invention can be selected from a wide range as long as it has the above-mentioned performance, but the water pressure resistance is 500 mmH ₂ O or more, more preferably 1200.
mmH ₂ O or more, water vapor permeability of 500 g / m ² · 2
4 hours or more, preferably 2000 g / m ² · 24 hours,
More preferably, 5000 g / m ² · 24 Hr is desirable.

Here, the water pressure resistance is a value measured by the JIS-L-1092A method, and the water vapor permeability is a method defined in JIS-Z-0208. If the water vapor permeability is too low, the water cannot be sufficiently supplied to the water-absorbing roots, so that the plant cannot grow. If the water pressure resistance is too low, a large amount of salt-containing water is supplied to the water-absorbing roots, resulting in salt damage.

The fabric in the present invention is selected from the above-mentioned fabrics as long as it has the above-mentioned physical properties, but a non-woven fabric is preferable, and the average fiber diameter is 5 μm or less,
It is more preferable to use a superfine fiber non-woven fabric having a basis weight of 15 g / m ² or more. Particularly, when the average fiber diameter is 4 μm or less, the moisture permeability is hardly impaired, the water pressure resistance is large, and the waterproof property is excellent, which is more preferable. Furthermore, the average fiber diameter is 3
The thickness of not more than μm is preferable because the waterproof property is improved while maintaining the practical moisture permeability. Here, the average fiber diameter is 300 times from the large photograph of 1000 times (scanning electron microscope).
The fiber diameters of not less than the number of fibers were read and the average value thereof was used. If the basis weight is too small, the water vapor transmission rate is excellent, but the water pressure resistance is low, resulting in poor waterproofness. On the other hand, if the weight is too large, the water vapor transmission rate is excellent, but the water vapor transmission rate is gradually reduced, and the cost becomes high.
g / m ² or more is preferable, more preferably 20 g / m ²
Although the above is not particularly limited, the upper limit is preferably 200 g / m ² or less.

In the present invention, it is preferable to apply mulch to the surface of the cultivated land so that the water vapor that has permeated the cloth can be efficiently used for growing plants. The primary purpose of mulch is to suppress the evaporation of water, but other functions such as protecting the roots of plants from radiant cooling at night, preventing falls due to wind, and preventing sand from entering. There is also. The mulch material used here is preferably one having air permeability. Examples thereof include, but are not limited to, films and nonwoven fabrics such as polyethylene having oxygen permeability, polypropylene nets and rough cloths, and gravel mulches in which crushed stones are arranged in a plane.

Depending on the temperature of the area to which the present fabric is applied and the type of target plant, the amount of water vapor that permeates the present fabric may be insufficient for plant growth. In such a case, in general, the specific heat of water is higher than the specific heat of the cultivated land soil, so it is difficult to cool the water temperature at night, focusing on the fact that dew condensation easily occurs in the cultivated land soil of water vapor that has passed through the cloth, Mixing a water retaining material with the medium is also preferable in that the permeated water vapor can be efficiently used. Water retaining material is usually 10 of its own weight
Although a substance which absorbs about 0 to 1000 times pure water is commercially available, the absorption capacity of an aqueous solution in which water-soluble salts are dissolved is significantly reduced. The water-retaining material is commercially available as a polymer hydrogel such as an acrylic resin or a cellulosic resin which is processed into powder, granules, lumps, or sheets, but is not limited thereto. Although the method of use cannot be generally stated depending on the shape and material, it is usually used by mixing 0.01 to 20 parts by weight of the used soil with the soil.

In order to make more effective use of the water vapor that has permeated the fabric, the water temperature is increased to promote the generation of water vapor in addition to or in combination with the use of mulch and a water retaining material, and the temperature of the plant cultivation layer is increased. It is also effective to allow it to cool to promote the condensation of permeated water vapor.

In the present invention, the method of arranging the present fabric in water or on the surface of water in which water-soluble salts are present, and providing a plant cultivation layer on the upper part thereof is not particularly limited, but a fabric floated in water may be used. Examples thereof include a method in which a vegetation layer composed of a soil layer or an aqueous layer is provided on the upper side, and plants are grown therein, and a method in which soil and plants are put in a cup-shaped or bag-shaped cloth and floated in water. As an example, an apparatus in which the present fabric is arranged in a container having holes on at least a part of the water surface such as the bottom surface is used (FIG. 1). At this time, it is more preferable to attach a buoyancy member to facilitate floating on the water surface. Another example is an apparatus (FIG. 2) in which the present cloth is placed on the upper part of the container, and water is supplied to the inside of the container so as to come into contact with the cloth, and a plant cultivation layer is further provided on the upper part of the cloth. At this time, it is more effective to stir or circulate the water in order to suppress the polarization of the salt concentration on the water surface.

[0021]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

Example 1 A non-woven fabric obtained by calendering a sheet having an average fiber diameter of 1.03 μm, a density of 0.37 g / cm ³ , a basis weight of 62 g / m ² , and a thickness of 0.17 mm was used in a seed germination test. The moisture permeability of this nonwoven fabric was 5200 g / m ² · 24 hr, and the water pressure resistance was 1600 mmH ₂ O.

Water or saline solution having a predetermined concentration is put in the container bottom of medium deep dish No. 4 having an upper diameter of 12 cm, a lower diameter of 10 cm, and a depth of 3 cm, and the nonwoven fabric is fixed so that the nonwoven fabric is in contact with the saline solution. Created a device. On this non-woven fabric, 160 g of paddy soil (one with a 1 mm mesh sieve was used to adjust the particle size, water content 0.8%) was placed at a temperature of 24
I left it down. After 26 hours, the paddy soil was weighed. As shown in Table 1, in each experiment, 15 g or more of water was supplied to the paddy soil through this nonwoven fabric in each experiment.

Further, 150 g of paddy soil (having a particle size of 1 mm mesh sieve, water content 2.5%) was placed on the above-mentioned device, and 3 seeds of barley were spread on this soil, 3 seeds per plate. It was left under a temperature of 25 degrees. When the germination rate was calculated by counting the number of germinated individuals after a predetermined number of days, the results shown in Table 1 were obtained.

Example 2 A nonwoven fabric made of polypropylene ultrafine fibers having an average fiber diameter of 1.3 μm was obtained by the melt blow method. The average fiber diameter measured by the spunbond method was 21.8 μm on both sides of this nonwoven fabric.
Laminated non-woven fabric, thickness 0.49mm, density 0.47
A composite non-woven fabric of g / cm ³ was obtained. The moisture permeability of this non-woven fabric is 900 g / m ² · 24 hr, and the water pressure resistance is 1500 mmH _2.
It was O.

Water or saline solution having a predetermined concentration is put in the bottom of a medium deep dish No. 4 having an upper diameter of 12 cm, a lower diameter of 10 cm and a depth of 3 cm, and the nonwoven fabric is contacted with the saline solution to form a nonwoven fabric. A fixed device is prepared, and 160 g of silica sand (having a particle size of 0.1 mm mesh sieve to have a uniform particle size, water content of 0.9%) is further provided with a water retaining material (Acryhope (manufactured by Nippon Shokubai Co., Ltd.)). Soil mixed with 0.0 g was placed and left at a temperature of 24 ° C. After 26 hours, the weight of the soil was weighed, and 150 g of silica sand (the particle size was adjusted with a sieve of 0.1 mm mesh) on the above device. thing,
Soil containing 1.0 g of water retention material (Acryhope (manufactured by Nippon Shokubai Co., Ltd.)) was placed in a water content of 2.5%, and 3 seeds of barley were sown on this soil, 3 seeds per plate, and left at a temperature of 25 ° C. The results of calculating the germination rate by counting the number of germinated individuals after a predetermined number of days are as shown in Table 1.

Example 3 A non-woven fabric made of polyester (manufactured by Awa Paper Co., Ltd.) having a thickness of 0.10 mm, a density of 0.925 g / cm ³ , and a basis weight of 92.5 g / m ² was added to a fluorine-based water repellent treatment agent (Asahi Guard AG).
After applying -650 (manufactured by Asahi Glass Co., Ltd.), heat treatment was performed.
The moisture permeability of this nonwoven fabric was 615 g / m ² · 24 hr and the water pressure resistance was 575 mmH ₂ O.

Water having a temperature of 35 ° C. or a saline solution having a predetermined concentration was put in the bottom of a medium deep dish No. 4 having an upper diameter of 12 cm, a lower diameter of 10 cm, and a depth of 3 cm, and the non-woven fabric was contacted with the saline solution. Then, a device with a fixed non-woven fabric was prepared. 160 g of silica sand (having a uniform particle size with a 0.1 mm mesh sieve, water content 0.9%) is placed on this device, and after mulching with a polyethylene sheet with a thickness of 0.03 mm, the temperature is 20 degrees. I left it down. 26 hours later,
The weight of silica sand was weighed, and the results are shown in Table 1.

Further, 150 g of silica sand (0.
Place a 1 mm mesh sieve to match the particle size, water content 2.5%), spread 3 seeds of barley on this soil per plate, mulch the soil surface with a polyethylene sheet, and then heat at 20 ° C. I left it down. The results of calculating the germination rate by counting the number of germinated individuals after a predetermined number of days are also shown.

Comparative Example 1 A germination experiment was carried out using filter paper in the same manner as in Examples 1 and 2, but no germination was observed at a salt concentration of 100 mM to 600 mM.

[0031]

[Table 1]

[0032]

EFFECTS OF THE INVENTION The plant growing sheet of the present invention exhibits the following effects for agricultural production in dry areas or coastal areas where good quality agricultural water is insufficient.

(1) Agricultural production using water having a high salt concentration is possible without constructing a large-scale facility or using an excessive energy source.

(2) It is possible to use groundwater or seawater having a high salinity and to effectively remove the salt to supply to crops even in a region such as a dry land where the water source is scarce or a coastal area, No large-scale irrigation equipment is required.

(3) Since agricultural production can be carried out without using unrecoverable chemicals such as chemicals, the influence on the environment such as pollution of groundwater veins is extremely small.

[Brief description of drawings]

FIG. 1 is an apparatus in which the present fabric is placed in a container having holes on the bottom surface of the present invention.

FIG. 2 is a device in which the cloth is arranged on the upper part of the container, water is supplied to the inside of the container, and a plant cultivation layer is further provided on the upper part of the cloth.

[Explanation of symbols]

 1: Growth sheet 2: Container 3: Plant cultivation layer 4: Plant 5: Hole 6: Water or aqueous solution of water-soluble salt 7: Water supply part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tadahiro Uemura 1-1-1, Sonoyama, Otsu City, Shiga Prefecture Toray Industries, Inc. Shiga Plant

Claims (19)

[Claims] 1. When the water-soluble salt is placed in water or on the surface of the water and a plant cultivation layer is provided, water vapor permeates, and water or an aqueous solution of the water-soluble salt does not substantially permeate, and is water-soluble. A plant-growing sheet comprising a cloth having a function of suppressing the movement of salts toward the water-absorption root side of plants. 2. The cloth has a moisture permeability of 500 g / m ² · 2.
The plant growing sheet according to claim 1, which has a water pressure resistance of 4 mm or more and a water pressure resistance of 500 mmH ₂ O or more. 3. The plant growing sheet according to claim 1, wherein the cloth is made of an ultrafine fiber nonwoven fabric having an average fiber diameter of 5 μm or less and a basis weight of 15 g / m ² or more. 4. The plant growing sheet according to claim 1, wherein a layer for reinforcing strength is attached to at least a part of the cloth to form a composite integrated structure. 5. The plant growing sheet according to claim 4, wherein the layer for reinforcing strength is a non-woven fabric made of stretched fibers. 6. The plant growing sheet according to claim 4, wherein the layer for reinforcing strength is a polymer film having fine pores. 7. A water-soluble salt is present in order to suppress migration of the water-soluble salt to a water-absorbing root side of a plant in a cloth which is permeable to water vapor but is substantially impermeable to water or an aqueous solution of the water-soluble salt. A vegetation method characterized in that it is placed in water or on the surface of the water, and a plant cultivation layer is provided. 8. The cloth has a moisture permeability of 500 g / m ² · 2.
The vegetation method according to claim 7, which has physical properties of 4 Hr or more and a water pressure resistance of 500 mmH ₂ O or more. 9. The vegetation method according to claim 7, wherein the cloth is made of an ultrafine fiber nonwoven fabric having an average fiber diameter of 5 μm or less and a basis weight of 15 g / m ² or more. 10. The vegetation method according to claim 7, wherein a layer for reinforcing the strength is attached to at least a part of the cloth for composite integration. 11. The vegetation method according to claim 10, wherein the layer for reinforcing strength is a non-woven fabric made of stretched fibers. 12. The vegetation method according to claim 10, wherein the layer for reinforcing strength is made of a film having fine holes. 13. The vegetation method according to claim 7, wherein the surface of the plant cultivation layer is mulched. 14. A cloth is coated with a cloth having water vapor or a water-soluble salt aqueous solution which has pores on at least a part of its surface which is in contact with water or a water-soluble salt aqueous solution. A plant cultivation device, wherein a plant cultivation layer is provided inside the container. 15. The cloth has a moisture permeability of 500 g / m ² ·.
The plant cultivating apparatus according to claim 14, which has physical properties of 24 Hr or more and a water pressure resistance of 500 mmH2 O or more. 16. The plant cultivating apparatus according to claim 14, wherein a buoyancy member is attached to facilitate floating on the water. 17. A cloth permeable to water vapor and substantially impermeable to water or an aqueous solution of a water-soluble salt is disposed on the upper part of the container, and a sufficient amount of water or an aqueous solution of a water-soluble salt is contacted with the cloth inside the container. The plant cultivating apparatus, wherein a plant cultivating layer is provided on the upper part of the cloth while replenishing. 18. The plant cultivation apparatus according to claim 14, wherein water or an aqueous solution of a water-soluble salt is stirred or circulated. 19. The plant cultivation device according to claim 14, wherein the surface of the plant cultivation layer is mulched.