JP2001204264A - Nursery sheet and nursery bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nursery sheet which secures the water retainability of nursery bed, improve the germination of seeds, save the human labor force by decreasing both of irrigation frequency and the mass of the nursery bed for the period of raising seedlings and do not negatively affect the growth and development of plants and a nursery bed. SOLUTION: In this nursery sheet and this nursery bed, the following hydrogel-forming polymer exists: the absorbed amount of calcium is 0-100 mg per 1 g dry weight; the contained amount of chloride ion is 0.07-7 mmol per 1 g dry weight; and the multiplying factor of water absorption is 1.0×101 to 1.0×103 at 25 deg.C in ion-exchanged water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nursery sheet and a nursery bed used for sowing and raising seedlings before planting cereals, vegetables, flowers and the like.

[0002]

2. Description of the Related Art The seeding work of cereals, vegetables, flowers and the like is roughly divided into the following two methods.
One is a direct sowing method in which seeds are sown and germinated and grown directly in a field, and the other is a seedling container in which small-area seedling raising units are assembled or a seedling box that grows in a mat-shaped group seedling. This is a method of sowing seeds on a nursery bed, germinating and raising the seedlings, growing them, and then planting them. In particular, in recent years, the latter method, that is, a method of first sowing seeds on a nursery bed, allowing them to grow, and then planting them, is generally performed by improving and rationalizing sowing work. However, the conventional seedling raising method using a nursery bed such as a seedling raising box and a seedling raising container always controls the water condition of the cultivated soil, and it is necessary to irrigate at least several times a day. About 5-8.5k
It takes a great deal of labor and labor to handle such as being heavy and heavy. Therefore, in recent years, various hydrogel-forming polymers that are insoluble in water and absorb a large amount of water when in contact with water have been proposed and used as soil water retention agents.

[0003]

However, although they have sufficient water retention performance, direct contact of a part of the plant, for example, a root with a hydrogel-forming polymer, adversely affects the growth of the plant. May kill plants. An object of the present invention is to reduce the human labor by reducing the number of times of irrigation and the mass of the nursery bed during the seedling raising period,
Another object of the present invention is to provide a nursery sheet and a nursery bed that do not adversely affect the growth of plants.

[0004]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that the above objects can be achieved by using a specific hydrogel-forming polymer, and have reached the present invention. did. That is, the present invention
(1) to (3). (1) A nursery sheet or nursery bed in which the following hydrogel-forming polymer (A) is present; Hydrogel-forming polymer (A): Calcium ion absorption is 0 to 100 mg per 1 g of dry weight. And the content of chloride ions is 0.07 to 7 m per gram of dry weight.
and a hydrogel-forming polymer having a water absorption capacity of 10 to 1,000 times in ion-exchanged water at 25 ° C. (2) The seedling raising sheet comprises a water-permeable sheet and / or a water-soluble or water-disintegrable sheet or a laminate sheet thereof (E) and (A), wherein (A) is at least one.
(3) a seedling sheet that is present on the surface and / or inside of (E); (3) a container with an open top filled with a medium therein, and a seedling sheet laid on the top of the container and the medium. Nursery beds equipped with.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the hydrogel-forming polymer (A) has a crosslinked structure or a network structure, and retains water based on the structure to form a hydrogel. Refers to a polymer having the property of forming In addition, the “hydrogel” refers to a gel containing at least a crosslinked or network structure made of a polymer and water supported or held (dispersed liquid) in the structure.

In the present invention, the hydrogel-forming polymer (A) includes, for example, (1) starch or cellulose (a) and a water-soluble monomer containing a hydrophilic group such as a carboxyl group or a sulfonic acid group and / or Or one or more monomers selected from monomers that become water-soluble by hydrolysis (b),
A water-absorbent resin obtained by polymerizing a crosslinking agent (c) as an essential component and, if necessary, hydrolyzing. (A), (b)
The proportions of (C) and (C), the production method and specific examples of the water-absorbing resin are described in JP-A-52-25886, JP-B-53-46199, JP-B-55-21041 and JP-A-10-3164.
No. 40. (2) Those obtained by polymerizing (a) and (b) (hydrolyzate of starch-acrylonitrile graft polymer, cellulose-
(3) Crosslinked product of (a) (crosslinked product of carboxymethyl cellulose, etc.); (4) Copolymer of (b) and (c) (crosslinked polyacrylamide) Partial hydrolyzate, cross-linked acrylic acid-acrylamide copolymer, cross-linked polysulfonate (cross-linked sulfonated polystyrene, etc.), cross-linked polyacrylate / polysulfonate copolymer, vinyl ester -Unsaturated carboxylic acid copolymer saponified product (JP-A-52
-14689 and JP-A-52-27455), cross-linked polyacrylic acid (salt), cross-linked acrylic acid-acrylate copolymer, cross-linked isobutylene-maleic anhydride copolymer , Cross-linked polyvinyl pyrrolidone, and cross-linked carboxylic acid-modified polyvinyl alcohol); and (5) a polymer (b) having self-cross-linking properties (self-cross-linkable polyacrylate, etc.). Two or more of the above-mentioned hydrogel-forming polymers may be used in combination.

Among these hydrogel-forming polymers, preferred are those exemplified as (1) and (4), such as a crosslinked polyacrylamide copolymer, a crosslinked polyacrylic acid (salt), and a crosslinked polymer. Acrylic acid
Acrylate copolymer, cross-linked isobutylene-maleic anhydride copolymer, and cross-linked carboxylic acid-modified polyvinyl alcohol. The water absorption capacity of the hydrogel-forming polymer in the present invention depends on the cross-linked structure, particularly the cross-link density, and generally the lower the cross-link density,
The water absorption ratio tends to increase. In the present invention,
The crosslink density is from about 0.01 to about 10 mol%, preferably from about 0.05 to about 5 mol%, in mol% of the branch point relative to all monomers. When a crosslinked structure is introduced by a crosslinker, the copolymerization weight ratio of the crosslinker to all monomers (including the crosslinker itself) is about 0.005 to about 3 wt.%, Preferably about 0.01 to about 3 wt.%. It is about 2 wt.%.

In the present invention, the crosslinking density is about 10 mol%
When it is less than 1, the water absorption capacity of the hydrogel-forming polymer of the present invention increases, and the effect of the present invention as a water retaining agent for growing plants increases. On the other hand, when the crosslink density is about 0.01 mol% or more, the mechanical strength of the hydrogel-forming polymer becomes strong, and the handling becomes good. In the present invention, the shape, size, and the like of the aggregate of the hydrogel-forming polymer and the particles are not particularly limited, and for example, a powder, a granule, a lump (block), or the like can be used, and the size thereof can be used. Can be used from 1 μm to several cm. Depending on the purpose of use, these shapes,
The size and the like can be appropriately selected. For example, the average particle size is usually 5 to 5,000 μm, preferably 10 to 4.0
It is 00 μm, particularly preferably 100 to 900 μm.

The hydrogel-forming polymer (A) of the present invention has a calcium ion absorption of 0 to 100 mg per 1 g of dry weight. In the present invention, the “calcium ion absorption amount” can be suitably measured, for example, by the following method. (Measurement of Calcium Ion Absorption Amount) 1 g of a dry water retention carrier was added to 1 L of an aqueous calcium chloride solution having a calcium ion concentration of 200 mg / L, and left in a thermostat at 25 ° C. for 48 hours with occasional stirring. Swells the water retention carrier and absorbs calcium ions. The swollen water-retaining carrier is separated, and the calcium ion concentration in the remaining supernatant (the excess of the calcium chloride aqueous solution) is determined by atomic absorption analysis (A mg / L).

In this case, the following conditions can be used in the calcium ion analysis by the above-mentioned atomic absorption spectrometry. <Measurement conditions of atomic absorption spectrometry> Atomic absorption spectrometer: manufactured by Shimadzu Corporation, trade name: AA-6500 auto system Lighting condition: Ca # 8 Current: 10 mA / 0 mA Wavelength: 422.7 nm Slit width: 0.5 μm Based on the quantitative value (A) of the calcium ion concentration measured as described above, the amount of calcium ion absorbed per 1 g of the water retention carrier can be obtained by the following equation. When separating the water-retaining carrier and the supernatant, the uncrosslinked water-soluble polymer may be dissolved in the supernatant. Therefore, if necessary, the weight-average molecular weight may be limited to about 1,000 to 3,000. Separation by ultrafiltration using an ultrafiltration membrane is performed. Calcium ion absorption per 1 g of water retention carrier (mg
/ G) = 200-A

The “calcium ion absorption” measured by the above method is 100 per 1 g of the dry weight of the water-retaining carrier.
When the amount is more than mg, "calcium ion deficiency" is likely to occur in a plant body that comes into contact with the water retention carrier. In the present invention, the "calcium ion absorption amount" is 0 to 100 mg, preferably 0 to 80 mg, per 1 g of the dry weight of the water retention carrier. In particular, when a polyacrylate-based hydrogel-forming polymer is used, a method of cross-linking and polymerizing acrylic acid and an alkali metal salt of acrylic acid and then adding a polyvalent metal salt is preferably used. In particular, when calcium chloride or magnesium chloride is used as the polyvalent metal salt, the amount of Ca absorbed by the hydrogel can be controlled by replacing the alkali metal salt with Ca or Mg.

A conventional hydrogel comprising "a crosslinked product of an alkali metal salt of polyacrylic acid" has a remarkably higher water absorption capacity than a hydrogel comprising a nonionic hydrophilic polymer crosslinked product. Because of its high water absorption capacity, it has been conventionally used as a water retention carrier in the agricultural field. However, this hydrogel has a very large introduction amount of dissociative ionic groups (for example, an introduction amount of an alkali metal salt of acrylic acid is about 8 mmol or more per 1 g of dry resin), and calcium ions which are essential for plant growth are required. Heavy metal ions such as these tend to be adsorbed, thereby significantly inhibiting plant growth. On the other hand, when 0.3 to 7 mmol of a dissociable ionic group (for example, an alkali metal salt or an ammonium salt of a carboxyl group) is introduced per 1 g of a dry water-retaining carrier, calcium ion deficiency occurs in the plant. It has been found that a sufficient water retention effect (water absorption capacity in ion-exchanged water of 10 to 1,000 times) is sufficient for growing plants without the use of the same.

The alkali metal salt of the carboxyl group is preferably a sodium salt or a potassium salt. The content of the alkali metal salt of the carboxyl group is preferably from 0.3 to 7 mmol per 1 g of the dry water-retaining carrier. 0.3m
When it is at least mol, the water absorption capacity of the water retention carrier can be at least 10 times. On the other hand, when the content of the alkali metal salt of the carboxyl group is 7 mmol or less, the calcium ion absorption amount is 100 mg per 1 g of the dry water retention carrier.
Is difficult to exceed. The content of the alkali metal salt of the carboxyl group can be measured, for example, by the following method.

(Method for Measuring Content of Alkali Metal Salt of Carboxyl Group) The water-retaining material is sufficiently washed with ion-exchanged water and dried, and 0.2 g of the dried water-retaining material is weighed in a platinum crucible and then heated in an electric furnace. After incineration, the mixture is dissolved in 5 ml of 1N hydrochloric acid, distilled water is added to make a constant volume of 50 ml, and the cation concentration (DmM) is determined by atomic absorption analysis. The content of the carboxyl group salt in 1 g of the dry water retention material is calculated as D / 4 (mmol = 1 molar concentration in 1 liter). Since the concentration of the dry water retaining material in the solution for atomic absorption analysis used here is 0.2 g / 50 ml = 4 g / 1 L (liter) as described above, the content of the carboxyl group salt in 1 g of the dry water retaining material is included. The amount will be (D / 4) mmol.

At this time, the same conditions as those in the above-mentioned "calcium ion analysis" can be used for the cation by the atomic absorption spectrometry. In a preferred embodiment of the present invention, the “hydrogel-forming polymer” contains a “polyvalent metal salt of a carboxyl group”. Examples of the ion of the polyvalent metal salt include Ca2
+, Mg2 +, Al3 +, Ba2 +, Sr2 +, B3
+, Be2 +, Fe2 +, Fe3 +, Mn2 +, and the like. Among them, Ca2 +, Mg2 +, Al3 +, Ba
2+, Sr2 +, B3 +, Be2 + are preferable, and Ca2
+ Is particularly preferred. The content of the polyvalent metal salt is 0.1 to 0.1 g per dry weight of the “hydrogel-forming polymer”.
7 mmol, preferably 0.5 to 6.5 mmol
1, particularly preferably 1.0 to 6.0 mmol.

In the present invention, the “content of the polyvalent metal salt of the carboxyl group” can be measured, for example, by the following method. (Method for measuring the content of the polyvalent metal salt of the carboxyl group) The water-retaining material is sufficiently washed with ion-exchanged water and then dried.
Weighed in a platinum crucible, ashed in an electric furnace, dissolved in 5 ml of 1N hydrochloric acid, and added with distilled water to 50 ml
As a constant volume of, the polyvalent metal ion concentration (EmM) is determined by atomic absorption analysis. The content of the carboxyl group polyvalent metal salt in 1 g of the dry water retention material is calculated as E × valence / 4 (mmol). The valence of this polyvalent metal ion (for example, M
In the case of g ions, the valence = 2) uses the valence obtained by “weighted average” of the valence of each polyvalent metal ion when the polyvalent metal ions are mixed.

It is preferable that (A) has 3 to 17 mmol of carboxyl groups bonded to the polymer chain per 1 g of dry weight. When the content is 3 to 17 mmol, the water retention performance and the growth of the plant are further positively affected.

The hydrogel-forming polymer (A) of the present invention has a chlorine ion content of 0.1 g / g dry weight.
It is necessary to be in the range of 07 to 7 mmol. The chloride ion content can be measured, for example, by the following method. (Measurement of Chloride Ion Content) 0.2 g of a hydrogel-forming polymer in a dry state is immersed in 200 ml of ion-exchanged water and left for 2 days. The supernatant was filtered through a filter, and the chloride ion concentration in the filtrate was measured using an ion analyzer (Ion
Analyzer IA-100, Toa Denpa Kogyo). Based on the chlorine ion concentration obtained in this way,
The amount of chlorine ions in 200 ml of the above ion-exchanged water is determined by calculation, and the calculated value is defined as the amount of chloride ions in “0.2 g of dry hydrogel-forming polymer”.

At this time, the following conditions can be used in the chlorine ion analysis by the ion analyzer. <Measurement Conditions of Ion Analyzer> Column: Anion column PCI-201S (manufactured by Toa Denpa Kogyo) and card column PCI-201SG
(Toa Denpa Kogyo Co., Ltd.) Solvent: Anion eluent (Toa Denpa Kogyo Co., Ltd.) Column bath temperature: 40 ± 4 ° C. The “chlorine ion content” measured by the above method is based on 1 g of dry weight of the water-retaining carrier. When it is within the range of 0.07 to 7 mmol, "calcium ion deficiency" can be suppressed as shown in Examples described later. Preferably from 0.5 to 6.5 mmol, particularly preferably from 1.0 to
6.0 mmol. If it is less than 0.07 mmol, the growth of roots and stems is liable to be inhibited, and if it exceeds 7 mmol, the absorption capacity of the water-retaining carrier is significantly reduced. This is because the growth of the stem is easily inhibited. The kind of the counter cation of the chloride ion is not particularly limited, but is preferably Na, K, Ca, or NH 4 ion. Among them, Na ions are particularly preferable.

The method for incorporating chlorine ions into the water retaining material for growing plants of the present invention can be carried out by absorbing an aqueous solution containing chloride ions into a hydrogel-forming polymer. In addition, when a hydrogel-forming polymer is synthesized in water, it is more preferable to include a chloride ion in the aqueous solution. At this time, the amount of chlorine ions to be added is set to be 0.07 to 7 mmol per 1 g of dry weight of the obtained water retention material. If the hydrogel-forming polymer already contains chloride ions in an amount of 7 mmol or more per 1 g of dry weight, the polymer does not contain chloride ions (or has a low chloride ion concentration).
By washing with water, the chlorine ion content can be reduced to a desired set value.

In the present invention, the water-absorbing power of the hydrogel-forming polymer is usually 10 to 1,000 times, preferably 30 to 900 times, particularly preferably 50 to 8 times.
It is 00 times. If the water absorption ratio is less than 10 times, it is difficult to supply sufficient water to the plant when a certain amount of the water retention material is used. It is difficult to produce a polymer having a water absorption ratio exceeding 1000 times. In the present invention, the “water absorption capacity in ion-exchanged water” can be measured, for example, by the following method. (Measurement of water absorption capacity in ion-exchanged water) A fixed amount (W1 g) of the dry water-retaining material was weighed, and an excess amount (for example, 1.5 times or more the expected water absorption of the water-retaining material) of ion-exchanged water (electricity) was measured. (Conductivity: 5 μS / cm or less) and left in a thermostat at 25 ° C. for 48 hours to swell the water retention material. After removing excess water by filtration, the weight (W2 g) of the water retention material that has swollen by water absorption is measured, and the water absorption capacity is determined by the following equation. Water absorption ratio = (W2-W1) / W1 In the measurement of the water absorption ratio, the weights W1 and W2 are measured, for example, using a precision electronic balance (LIBROR A, manufactured by Shimadzu Corporation).
EG-220; LIBROR EB-3200-D).

The mass ratio of water to (A) in the hydrogel of the present invention can vary depending on the type of (A) and the optimal water content of the plant, but is usually 99.9: 0.1 to 8
0:20, preferably 99.2: 0.2 to 91: 9, more preferably 99.7: 0.3 to 94: 6.
When (A) is 0.1 or more, the water retention capacity becomes sufficient, and when it is used at 20 or less, it is preferable from an economic viewpoint.

The sheet (E) in the present invention includes a water-permeable sheet and / or a water-soluble or water-disintegrable sheet or a laminate sheet thereof.
(E) has a thickness of 0.01 after being formed into a seedling raising sheet.
The thickness is preferably 9 mm, more preferably 0.02 mm to 3 mm. The mass of (E) is from 5 to 300 g, preferably from 10 to 300 g, per unit volume (m 2) of the seedling raising sheet, in order to secure shape retention and thickness of the seedling raising sheet.
100 g. As the water-permeable sheet in (E), a sheet having a water-absorption rate of 5 minutes or less according to the water-absorption rate A method described in JIS L 1096 is preferable. Further, it is preferable to have appropriate air permeability and properties that are easily decomposed on the soil surface or inside when the sheet is attached to the ground so as not to inhibit the germination and growth of seeds. (Woven fabric), non-woven fabric, paper, water-soluble polyvinyl alcohol fiber woven or knitted fabric, film, paperboard and the like. Of these, cellulosic paper and nonwoven fabric are preferred.

As the water-disintegrable sheet in (E), for example, paper pulp fibers may be combined with a water-soluble or hydrophilic paste,
Paper (such as "Disorvo MDP" manufactured by Mishima Paper Co., Ltd.) that is made to adhere by water swellable polymer so that the pulp fibers are disintegrated apart by contact with water. Paper with added moldability (thermal adhesion) ("Disorvo MDP" manufactured by Mishima Paper Co., Ltd.)
-P ") and the like. These papers have a feature that the speed of disintegration by water absorption is high. Examples of the water-soluble sheet in (E) include a water-soluble film such as a water-soluble poval film, a starch film, and a carrageenan film, and a water-soluble nonwoven fabric made of a poval fiber ("Eco-Mold" Ecosolve ”etc.). When compared with the same thickness, these sheets are inferior in water dissolution (disintegration) rate to the above-mentioned water-disintegrable paper, but are characterized by high sheet strength in a dry state.

The laminated sheet obtained by laminating the water-disintegrable paper and the water-soluble film is preferably at least one, preferably 1 to 6 or 7 or more, more preferably 1 to 3 sheets. Examples thereof include those obtained by bonding and laminating a water-disintegrable paper and a water-soluble film (“Disorbo A” manufactured by Mishima Paper Co., Ltd., which is obtained by laminating a poval film to the above “Disorvo MDP”). These laminate sheets are characterized in that they dissolve (disintegrate) in water quickly and have high film strength. this is,
Since the thickness of the water-soluble film to be attached can be reduced by the strength of the paper, both the dissolution (disintegration) rate and the film strength can be improved as a whole. Preferred among these water-soluble or water-disintegrable sheets are:
Water-disintegrating paper and water-soluble nonwoven fabric. The time required for these water-soluble or water-disintegrable sheets to disintegrate or dissolve in water is usually within 5 minutes, preferably within 2 minutes,
More preferably, it is within one minute. Also, a sheet or the like combining these sheets and a water-permeable sheet can be used.

The seedling-raising sheet of the present invention comprises (A) and (E), wherein (A) is at least one, preferably 1 to 6 or more, more preferably 1 to 3 sheets of (E).
It is a seedling raising sheet existing on the surface or inside. The amount of (A) to be added to the seedling raising sheet of the present invention is determined by the amount of water retention required for the sheet due to germination and the like, and the water absorption capacity of (A). The amount of (A) added is preferably 1 to 100 g per unit area (m2) of the seedling raising sheet,
More preferably, it is 5-80 g.

The seedling-growing sheet of the present invention can contain a filler (B) and a fertilizer (C) in addition to (A) and water.
Furthermore, one or more selected from the group (D) consisting of preservatives, fungicides, insecticides, herbicides, phytohormones, and surfactants can be used in combination. The filler (B) is preferably a powdery, granular, fibrous or flocculent filler. As (B), those having appropriate air permeability so as not to inhibit the germination and growth of seeds;
Those that do not adversely affect the soil when attached to the ground and / or that have properties that are easily decomposed on or in the soil surface are preferable. For example, perlite, vermiculite, inorganic porous materials such as rock fiber, wood chips, Fir, buckwheat, rice bran, cotton, straw, peat,
Examples include wool, sawdust, pulp, and paper waste. (B)
Is usually 1 to 500 g per unit area (m 2) of the seedling raising sheet, in order to secure the air permeability and the thickness.
Preferably it is 3-300 g.

As the fertilizer (C), nitrogenous fertilizer, phosphate fertilizer, potassium fertilizer, organic fertilizer, compound fertilizer, calcareous fertilizer, siliceous fertilizer, magnesia fertilizer, manganese fertilizer, boronaceous fertilizer, trace amount Examples include ordinary fertilizers such as element compound fertilizers and other special fertilizers (slow-release fertilizers and the like). These fertilizer components are liquid or solid such as powder, and by being added to a hydrogel-forming polymer,
Alternatively, it can be present in the seedling-growing sheet by including it in water injected into the hydrogel-forming polymer. The amount of (C) added can be arbitrarily determined in consideration of the type of crop to be cultivated, the type of fertilizer to be used, and the like, but is usually 1 to 5 per unit area (m 2) of the seedling raising sheet.
00 g, preferably 3 to 300 g.

As preservatives, halogen-supplying agents, especially chlorine-supplying agents, such as chloro-cyanuric acids or salts thereof, especially mono-sodium or potassium dichloroisocyanurate; hydroxyquinones, sulfites; and silver or copper salts And two or more of them may be used in combination. Disinfectants include TPN, cabtan, pinclozolin, brassmidone, benzazole, quaternary ammonium salts, phenolic compounds, quaternary pyridinium salts, peracids, formaldehyde, antibiotics (penicillin, streptomycin, chloramphenyl alcohol, etc.) ), N-chlorosuccinimide, lime, sulfur, organic sulfur agent (Zineb,
Maneb, thiodiazine, thiuram, etc.), mono- and dithiocarbamate, thiodiazine, sulfonamide,
Phthalimide, petroleum ether, naphthoquinone, benzoquinone, disulfide, mercuric compound, tetrahydrophthalimide, arsenate, cupric salt, organic copper agent (8-
Copper oxyquinoline), guanidine salt, triazine, glyoxalidine salt, quinolinium salt, phenylcrotonate and the like, and two or more kinds thereof may be used in combination.

As the insecticide, for example, MEP, MP
P, benflacarb, carbofuran, carbosulfan, ethyl thiometon, thiocyclam, PHC, cartap, bensultap, diazinon, probaphos, acephate, bendiocarb, bamidione, ethoxazole, etc., and two or more of them may be used in combination. Examples of herbicides include butachlor, chloronitrophen, nitrophen, cyhalofop butyl, cafenstrole, bensulfuron-methyl, dimelone, teclchlor, imazosulfuron, preticachlor, dimethamethrin, pentoxazone, isopropylammonium = N- (phosphonomethyl) glycinate and the like. And
Two or more kinds may be used in combination.

Examples of plant hormone agents include auxins such as 2,4-D, cytokinins such as kinetin, gibberellins, and the like, and two or more thereof may be used in combination. If there is a possibility that each component is decomposed when the above components are mixed, each component can be contained in a separate sheet, and the sheets can be applied in an overlapping manner. Examples of the surfactant include conventionally known nonionic surfactants (eg, polyethylene glycol type, polyhydric alcohol type surfactants, etc.), anionic surfactants (eg, soap, sulfate ester type, sulfonate) Type, phosphate ester type surfactant, etc.), cationic surfactant (eg, amine salt type, quaternary ammonium salt type surfactant, etc.), amphoteric surfactant (eg, amino acid type, betaine type surfactant) Activator, etc.) and the like, and two or more kinds may be used in combination. As the amount of (D) to be added, the type of crop to be cultivated and the (D) to be used
Can be arbitrarily determined in consideration of the type of the seedling, etc., but is usually from 0.0001 to
500 g / m2, preferably 0.0003 to 300 g /
m2.

In this seedling raising sheet, in addition to (A), (B), (C) and (D) can be present in at least one sheet (E). (B),
(C) and (D) may exist in (E) different from (A). When two or more sheets of (E) are used for the seedling raising sheet, at least one sheet, preferably 1 to 6 sheets or 7
(A) may be present on the surface or inside of at least one, more preferably one to three sheets of (E). Examples of two or more seedling raising sheets include, for example, layer (E) and layer (C).
Having a five-layer structure including a layer of (B), a layer of (E), a layer of (A), (B) and (D), and a layer of (E);
A layer having a four-layer structure including two layers of (E), a mixed layer of (A) to (D), and a layer of (E) is exemplified.

In the present invention, as a method for producing a seedling raising sheet, a usual method, for example, a method of immersing (E) in a mixture of (A) to (D), or a method of applying the mixture to the surface of (E) can be mentioned. Can be (A) to (D) may be a mixture or alone. In the case of a mixture, it is preferably (A) by mass ratio:
(B): (C): (D) = 1 to 100: 1 to 500: 1
-500: 0.0001-500, more preferably 5-80: 3-300: 3-300: 0.0003.
~ 300. When two sheets of (E) are used, for example, the following two methods can be used in addition to the method of creating the same method and overlapping the two sheets. One obtained by uniformly mixing a mixture of (A) to (D) on one (E), and then superimposing the other (E) and further performing pressure molding such as embossing. One (E) is coated with a mixture of (A) to (D) added to an appropriate binder (F), and the other water-permeable sheet (E) is laminated and formed. , Dried.

When (E) is three or more, it is conceivable to perform processing by a combination of the single method of the above-described method and the single method of two or the same method as in the case of two. . In the present invention, the length, width and thickness of the seedling raising sheet are not limited as long as it is within the size of a seedling raising box (plastic container) generally distributed on the market. It is preferable that the length is set to be within 1 to 5 cm in each of the length and width directions. For example, a nursery box for rice (58cm * 28cm)
In the case of, a size of 58 to 53 cm in length and 28 to 23 cm in width is preferable. The thickness of the seedling raising sheet is preferably as thin as possible from the viewpoint of distribution cost and production, and generally, a thickness of 0.01 mm to 20 mm is preferable.
More preferably, it is 0.02 mm to 10 mm. When providing nursery sheets on nursery beds, there is no particular limit on the number,
There is usually one nursery sheet on the nursery.

A binder (F) for fixing (A) to (D) on (E) can be used. (F) includes natural polymers, synthetic resins, natural and synthetic rubbers, and the like. Natural polymers include starch, carboxymethylcellulose, methylcellulose, ethylcellulose,
Examples include hydroxymethyl cellulose, hydroxyethyl cellulose, sodium alginate, guar gum, xanthan gum, bean gum, carrageenan, gluten and the like. As synthetic resins, acrylic resins, polyurethane resins, unsaturated polyester resins, polyamide resins,
Examples include an ethylene copolymer resin. Examples of natural and synthetic rubbers include natural rubber, acrylic rubber, butyl rubber, polyisobutylene rubber, styrene / butadiene rubber, ethylene / propylene rubber, chloroprene rubber, and the like. These can be used alone or in combination of two or more. Preferred among these are water-soluble polymers such as starch, carboxymethylcellulose and sodium alginate.

Subsequently, an adhesive layer is formed on the surface of the sheet, and seeds are further spread on the surface of the adhesive layer at predetermined intervals (for example, in accordance with the position of each compartment of the nursery bed to be laid). Place and fix. In this way, a sheet carrying seeds can also be manufactured. FIG. 2 shows such a sheet.
And FIG.

2 and 3, the pressure-sensitive adhesive layer 5 formed on the entire surface of the sheet 2 may be formed on the entire surface of the sheet 2.
It may be formed in a streak shape. Further, it may be formed only on the portion that supports the seed 6. The method for forming the pressure-sensitive adhesive layer 5 is not particularly limited, and examples thereof include spray coating, roller coating, brush coating, and screen printing.

Next, in FIG. 2 and FIG. 3, as the adhesive for supporting the seeds 6 on the sheet 2, the binder (F)
Suitable adhesives include, for example, general adhesives such as solvent-type and emulsion-type acrylic adhesives and ethylene-vinyl acetate copolymer (EVA) -based adhesives. In particular, water-soluble polymers can be used for water and alcohols, acetone, methyl ethyl ketone, acetonitrile,
10-30% by mass in solvents such as chloroform and ethyl acetate
It is preferable to use a dissolved one. And Figure 2,
As the seed 6 supported on the sheet 2 via the pressure-sensitive adhesive layer 5 in the sheet 3, any seed may be used as long as the seed 6 can be supported on the sheet 2. Examples of seeds include flowers (sunflower, poppy, salvia, morning glory, pansy, cosmos, etc.), grains (wheat, rice, buckwheat, etc.), vegetables (radish, eggplant,
Komatsuna, petit tomato, cucumbers, etc.).

The nursery bed of the present invention includes a container having an open top filled with a culture medium therein, and a nursery sheet laid on the top surface of the container and the culture medium. Examples of the open-top container filled with a medium therein used in the present invention include a box for raising seedlings (a seedling raising box) conventionally used for sowing work. Either a nursery sheet is provided in the nursery box or soil mixed with (A) is present. Here, the soil is preferably soil containing plant fertilizers such as flowers, vegetables, and cereals. Mountain soil, natural soil, and the presence or absence, content,
H, water permeability and air permeability are adjusted. (A) The mixed amount of the soil includes the type of crop to be cultivated, the permeability of the soil,
Although it can be arbitrarily determined in consideration of air permeability, it is preferably 0.01 to 200 g, more preferably 0.05 to 150 g per unit volume (L) of soil. As a typical example, as shown in FIG. 1, there is a container 7 having an open top divided into compartments 8 as shown in FIG. Each of the compartments 8 is filled with a culture medium 9. The medium 9 is not particularly limited, and includes a conventionally known medium such as soil, for example, a medium in which soil, sand, mulch and the like are used as a basic component and mixed with other additives such as fertilizer. Furthermore, the culture medium according to the present invention also includes a mat for raising seedlings such as urethane foam and water for hydroponics.

The nursery bed of the present invention is produced, for example, as follows. That is, first, as shown in FIG. 1, a container 7 having an open top divided into a plurality of compartments 8 is prepared, and each compartment 8 of the container 7 is filled with a medium 9. On the other hand, as shown in FIGS. 2 and 3, a sheet 1 having seeds 6 supported on the sheet 2 via an adhesive layer 5 is prepared. And FIG.
As shown in the figure, the upper surface of the container 7 filled with the culture medium 9,
The surface of the sheet 1 that does not support the seeds 6 is opposed to the surface.
At this time, the seeds 6 are laid so as to be positioned in the respective compartments 8 of the container 7. A nursery is thus produced. Further, after this, the sheet 1 may be covered with soil.

The nursery bed of the present invention thus obtained is used, for example, as follows. That is, FIG.
Is irrigated from above the nursery bed shown in (1) to absorb and swell the hydrogel-forming polymer (A) supported on the sheet 2. Hydrogel 3 'swollen with water as shown in FIG.
And the seeds 6 are placed on the.

Hereinafter, the present invention will be further described with reference to Examples showing Production Examples and Use Examples, but the present invention is not limited thereto. The following parts show parts by mass.

Example 1 [Preparation of Water Absorbent Resin] In a 1 liter beaker, 230 g of acrylic acid, 48%
Of sodium hydroxide aqueous solution, 1.0 g of pentaerythritol triallyl ether and 636 g of water were added, and cooled to 10 ° C. This solution was placed in an adiabatic polymerization tank, and the dissolved oxygen in the solution was adjusted to 0.1 ppm (measured by Orient Electric Co., Ltd., trade name: dissolved oxygen meter DO220PB) through nitrogen. Then, 0.023 g of 35% hydrogen peroxide solution was added.
0.00575 g of L-ascorbic acid and 0.23 g of potassium persulfate were added. The polymerization reaction started about 30 minutes after the addition, and reached a maximum temperature of 72 ° C. about 2 hours later. Further, the mixture was aged at this temperature for 5 hours to complete the polymerization. The obtained polymer had a hydrogel shape. This polymer is kneaded (made by Irie Trading Co., trade name BENCH KNEADE
(RPNV-1; rotation speed: 70 rpm) for about 2 hours with stirring for chopping, and 35.5 g of 50% calcium chloride aqueous solution.
Was stirred and mixed with a kneader for about 2 hours. Subsequently, it is dried by heating at 110 ° C. and then pulverized to an average particle size of 45.
0 micron (Nikkiso Co., Ltd., product name: Microtrack F
RA particle size analyzer), calcium ion absorption 85.4 (mg / g), chloride ion content 1.6
(Mmol / g) and water absorption resin A-1 (hydrogel-forming polymer) having a water absorption ratio of 309 (g / g).

[Preparation of seedling raising sheet] The above water-absorbent resin A
-1 (200 parts) and paper pulp (10
0 parts) and a basis weight of 30 g / m2.
Sprinkle as uniformly as possible at a rate of 30 g / m2 on the water-disintegrating paper of No. 2 and overlay a water-disintegrating paper of the same quality on the upper side.
Through the embossing roll, a nursery sheet was obtained in which the water-absorbent resin and the paper pulp were fixed between two pieces of water-disintegrated paper. Paper pulp: KC Floc W-100, manufactured by Nippon Paper Co., Ltd. Water disintegrating paper: Disolvo 300MDP, manufactured by Mishima Paper Co., Ltd.

Example 2 When 10 g of a commercially available polyacrylic acid-based hydrogel (manufactured by Sanyo Chemical Industries, trade name: Sun Fresh ST-500D) was swollen with 4 L of distilled water, 1 L of CaCl 2 was added.
A solution (Ca-containing 1 g; concentration 0.28%) was added, and the mixture was stirred well. After leaving for about 2 hours with occasional stirring, the gel was filtered off with a net (fineness of mesh: nylon mesh filter cloth, 250 mesh, manufactured by Azumi Filter Paper Co., Ltd., trade name: N-No250HD), and then dried (120 ° C.) For 1 hour. After drying, the mixture is crushed in a mortar to form a gel powder, having an average particle size of 4
50 microns, calcium ion absorption 62.9 (mg
/ G), a chlorine ion content of 0.6 (mmol / g), and a water absorption ratio of 244 (g / g) to obtain a water-absorbent resin A-2 (a hydrogel-forming polymer). Further, in Example 1, the "water-absorbent resin A-1" was used instead of the "water-absorbent resin A-1".
A nursery sheet was prepared in the same manner as in Example 1 except that "2" was used.

Comparative Example 1 A seedling-growing sheet was prepared in the same manner as in Example 1 except that "Sunfresh ST-500D" was used instead of "Water-absorbent resin A-1". Sunfresh ST-500D: polyacrylic acid-based hydrogel, average particle diameter 450 microns, calcium ion absorption 164 (mg / g), chlorine ion content 0 (mm)
ol / g), water absorption capacity 302 (g / g), manufactured by Sanyo Chemical Industries, Ltd. Comparative Example 2 # The same seedling raising sheet used in Example 1 was used, and the following seedling raising sheet without using a water-absorbent resin was prepared. Paper pulp as a filler component is sprinkled as uniformly as possible at a rate of 10 g / m 2 on a water-disintegrated paper having a basis weight of 30 g / m 2, and a water-disintegrated paper of the same quality is overlaid on the upper side and passed through an embossing roll. A nursery sheet in which paper pulp was fixed between sheets of water-disintegrated paper was obtained.

(Plant growth degree (a)) 30 cm × 20
5 kg of sandy soil (for example, river sand) was placed in a plastic planter of cm × 20 cm. Next, 7.5 kg of sandy soil was fed with a chemical fertilizer (nitrogen: phosphoric acid: potassium = 1: 1: 1).
1) 0.5 kg of the well-mixed soil was layered on a planter containing sandy soil, and each seedling-raising sheet was spread over the seedlings. Then, cucumber and radish were sown in a quantity of 20 grains each. 0.5 kg of sandy soil was uniformly charged and sufficiently irrigated. Two of these series were prepared, and one of them was irrigated with 50 g of ion-exchanged water every day, and the other was irrigated with 50 g of ion-exchanged water every other day.
After 14 days, the growth status (the average value of the germinated and grown strains) was observed.

[0048]

[Table 1]

[0049]

The following effects can be obtained by using the nursery sheet and nursery bed of the present invention. First, the plant can be supplied with sufficient water because it does not inhibit the growth of the plant and has an excellent water absorbing ability. In particular, "pots" such as cell molded seedlings, community pot seedlings, and pot seedlings, whose production and distribution are growing at a rapid rate in greenhouse horticulture, have recently suffered from a decrease in water retention due to the lightening of soil. Therefore, it can be effectively used as an implant material for improving water retention. Second, germination can be improved because of excellent water retention. In particular, in recent years, a method of using a seedling raising unit having a small area such as a nursery bed has been generally used due to rationalization of a sowing operation. The end of such a nursery bed is easier to dry than the central part, and there is a large difference in germination. As a result, inconveniences such as not being able to produce uniform seedlings as a whole nursery bed are caused. By using a seedling raising sheet, drying can be prevented and uniform germination can be ensured.

[0050]

[Brief description of the drawings]

FIG. 1 is a perspective view of a container filled with a culture medium constituting a nursery bed of the present invention.

FIG. 2 is a perspective view showing a seedling raising sheet of the present invention.

FIG. 3 is a sectional view showing a seedling raising sheet of the present invention.

FIG. 4 is a sectional view showing a nursery bed according to the present invention.

FIG. 5 is a cross-sectional view showing a state in which a nursery bed according to the present invention is irrigated, and a hydrogel-forming polymer has absorbed and swollen.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 seedling raising sheet 2 water-disintegrating paper 3 hydrogel-forming polymer 3 ′ hydrogel (state in which hydrogel-forming polymer has absorbed water and swollen) 4 paper pulp 5 adhesive 6 seed 7 seedling raising container 8 compartments 9 medium

Claims (11)

[Claims] 1. A nursery sheet or nursery bed comprising the following hydrogel-forming polymer (A). Hydrogel-forming polymer (A): Calcium ion absorption is 0-100 mg / g dry weight; Chloride ion content is 0.07-7 m / g dry weight
and a hydrogel-forming polymer having a water absorption capacity of 10 to 1,000 times in ion-exchanged water at 25 ° C. 2. The seedling-growing sheet according to claim 2, wherein said sheet is a water-permeable sheet and / or
Or a water-soluble or water-disintegrable sheet or a laminate sheet thereof (E) and (A), wherein (A) is present on the surface and / or inside of at least one (E). Seedling sheet. 3. The method according to claim 1, wherein (A) has a carboxyl group bonded to a polymer chain, and the content of the alkali metal salt or ammonium salt of the carboxyl group is 1% by dry weight.
The seedling raising sheet according to claim 1 or 2, wherein the amount is 0.3 to 7 mmol per g. 4. The seedling raising sheet according to claim 1, wherein (A) has a carboxyl group bonded to a polymer chain in an amount of 3 to 17 mmol per 1 g of dry weight. 5. The seedling raising sheet according to claim 2, wherein the filler (B) is present in at least one sheet (E). 6. The seedling raising sheet according to claim 2, wherein the fertilizer component (C) is present in at least one sheet (E). 7. At least one member selected from the group (D) consisting of a preservative, a bactericide, an insecticide, a herbicide, a plant hormonal agent, and a surfactant is present in at least one sheet (E). The seedling raising sheet according to any one of claims 2 to 6. 8. A nursery bed in which the nursery sheet according to claim 2 is provided on the nursery bed. 9. The nursery bed according to claim 1, wherein (A) is mixed with soil, or the nursery sheet according to any one of claims 1 to 7. 10. A container having an open top filled with a medium therein, and laid on the container and the top of the medium.
A nursery bed comprising the nursery sheet according to any one of claims 7 to 7. 11. The nursery bed according to claim 10, comprising a seedling raising sheet having seeds supported on one side of the seedling raising sheet via an adhesive layer.