JPH10127160A - Bondable mold and raising seedling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bondable mold which binds the particles constituting earth by drying from a water absorptive state, has not an effect of prohibiting growth of roots, has high weatherability and is useful for agriculture, horticulture, etc., by mixing the soil and a prescribed amt. of the crosslinked matter, etc., of the polymer of N-vinyl carboxylic acid amide. SOLUTION: This bondable mold is obtd. by mixing (A) the soil and (B) the crosslinked matter of the independent polymer of the N-vinyl carboxylic acid amide or the crosslinked matter of the copolymer of a (non)ionic monomer at 0.1 to 5.0wt.% of the weight of the soil. The particles constituting the soil are bonded by the drying from the water absorptive state. The crosslinked matter of the independent polymer of the N-vinyl carboxylic acid amide or the crosslinked matter of the copolymer of the (non)ionic monomer is the crosslinked matter of the independent polymer of N-vinyl acetoamide or the crosslinked matter of the copolymer of the (non)ionic monomer and is preferably the crosslinked matter of the independent polymer of N vinyl acetoamide or the crosslinked matter of the copolymer of the (non)ionic monomer having a crosslinking density of 1/5,000 to 1/10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cultivating and cultivating seedlings used for raising seedlings in the field of agriculture and horticulture, and more particularly to a method for cultivating and cultivating seedlings by drying and solidifying cultivation soil. About the method.

[0002]

2. Description of the Related Art Conventionally, in agricultural and horticultural work, seedling containers such as pots and trays are filled with cultivated soil, seeded in the cultivated soil, and seedlings are intensively grown. The grown seedlings are transplanted using a machine. The way to do it is widely done. Generally, when transplanting seedlings, in order to improve the survival rate of the seedlings,
It is preferable not to disintegrate the soil around the roots of the seedlings, especially in the case of mechanical transplanting, in order to improve the workability and prevent damage to the roots, combine the soil particles of the soil around the roots of the seedlings It is desired. As a method for binding soil particles of the cultivation soil, a technique of adding a substance such as a resin serving as a binder to the cultivation soil has been developed.For example, a water-absorbing resin having an adsorptive property, such as vinyl acetate / methyl acrylate, A method has been developed in which ionic water-absorbing resins such as polymer saponified products, sodium polyacrylate crosslinked products, and vinyl alcohol / acrylate copolymers are mixed into the soil to have both functions as a water retention agent and a binder. (See JP-A-58-31919).

However, such an ionic water-absorbing resin usually contains an ionic monomer in a ratio exceeding 30 mol%, and has a high ionization degree. It is known that such a water-absorbent resin having a high degree of ionization has a growth inhibitory effect on the root of a plant, and has a disadvantage that the yield is reduced or the cultivation period is lengthened. Although the ionic water-absorbing resin absorbs deionized water very well, the water-absorbing performance of an aqueous solution containing an ionic compound is low. Since fertilizers generally used contain a large amount of ionic compounds, there has been a problem that ionic compounds derived from fertilizers reduce the water absorption of the ionic water-absorbing resin by fertilization, and cannot exert a sufficient water retention function. In addition, acrylic acid-based (co) polymers have insufficient light resistance and biodegradation resistance, and have a problem that water retention and tackiness are reduced during cultivation.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a binding soil using a water-retentive binder which has high weather resistance, has no growth inhibitory effect on roots, and does not reduce water absorption by fertilization, and a method using the binding soil. A method for raising seedlings is provided.

[0005]

The binding soil according to the present invention is:
A soil and a homopolymer crosslinked product of N-vinylcarboxylic acid amide or a copolymer crosslinked product of any of ionic and nonionic monomers with 0.1 to 5.0% by weight of the soil; Are mixed, and the particles constituting the soil are combined by drying from a water-absorbing state. A crosslinked product of the homopolymer of N-vinylcarboxylic acid amide or a crosslinked product of a copolymer with any one of ionic and nonionic monomers is a crosslinked product of a homopolymer of N-vinylacetamide or ionic and nonionic A cross-linked product of a copolymer with any of the ionic monomers, the cross-link density of the homo-polymer cross-linked product of the N-vinylacetamide or the cross-linked product of the copolymer with any of the ionic and non-ionic monomers The configuration may be 1/5000 to 1/10. Also, the method for raising seedlings of the present invention is to fill the container for bonding seedlings having the above-described composition into a container for raising seedlings, sow the seedlings and watering the bonding seedlings to grow cultivated plants. %, And dried and solidified, and transplanted with cultivated plants.

[0006]

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a crosslinked homopolymer or copolymer of N-vinylcarboxylic acid amide not only has high water retention, but also exhibits surface tackiness in a water-absorbing state. Focusing on exhibiting an adhesive effect when dried through the state, this homopolymer crosslinked product or copolymer crosslinked product of N-vinylcarboxylic acid amide is used as an excellent water retention binder when binding the soil. Things. In the present invention, the connection of the cultivation soil refers to a state in which the cultivation soil is solidified to a strength sufficient to withstand the external force at the time of mechanical transplantation, and when the container is deformed by lightly pressing the bottom surface of the seedling growing container from the outside. In addition, it refers to a state in which the soil around the roots is removed from the container while maintaining the shape of the container without collapse. Further, in the binding soil of the present invention, in the state before water addition and in the state of water absorption and water absorption, soil particles in the soil growth are not bound, but as the soil is dried from the state of water absorption, the soil particles Are bonded and integrated as a porous body.

Hereinafter, the present invention will be described in more detail. The water retention binder used in the present invention is disclosed in
223304, JP-A-4-230250 and JP-A-4-230250
A homopolymer crosslinked product or a copolymer crosslinked product of N-vinylcarboxylic acid amide described in -346833,
Among them, a cross-linked homopolymer or copolymer of N-vinylacetamide (hereinafter referred to as “PNVA”) having high water retention and high adsorptivity is preferable, and a cross-linked homopolymer of N-vinylacetamide has high weather resistance. N-vinyl carboxylic acid amide is represented by the following formula (I).

[0008]

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In the formula (I), R ₁ and R ₂ represent hydrogen or a methyl group, R ₃ represents a hydrogen, a methyl group or an ethyl group, and R ₂ and R ₃ represent an alkylene group having 3 to 5 carbon atoms. It may be formed. Specifically, N-vinylacetamide,
N-methyl-N-vinylacetamide, N-vinylformamide, N-methyl-N-vinylformamide and the like can be mentioned.

The ionic monomers copolymerizable with N-vinylcarboxylic acid amide in the crosslinked N-vinylcarboxylic acid amide include, for example, (meth) acrylic acid, maleic acid, itaconic acid, 2-acrylamide −
2-methyl-propanesulfonic acid, 2-acrylamidoethanesulfonic acid, 2-methacrylamidoethanesulfonic acid, 3-methacrylamidopropanesulfonic acid, methyl acrylate acrylate, methyl sulfonic methacrylate, 2-ethyl sulfone acrylate Acid, methacrylic acid-2-ethylsulfonic acid, acrylic acid-3-propylsulfonic acid, methacrylic acid-3-propylsulfonic acid, acrylic acid-2-methyl-3-propylsulfonic acid, methacrylic acid-2-methyl-3 -Propylsulfonic acid, acrylic acid-1,1′-dimethyl-2-ethylsulfonic acid,
Methacrylic acid-1,1′-dimethyl-2-ethylsulfonic acid or a salt thereof. Examples of the nonionic monomer used in the crosslinked N-vinylcarboxylic acid amide copolymer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, acrylonitrile, methyl vinyl ketone , Ethyl vinyl ketone, vinyl acetate, methyl vinyl ether, ethyl vinyl ether, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. The copolymerization ratio of the ionic monomer is preferably 30 mol% or less, more preferably 20 mol% or less, based on the nonionic monomer. When the copolymerization ratio of the ionic monomer is 30 mol% or less with respect to the nonionic monomer, growth is not inhibited and water retention is satisfied.

A crosslinked N-vinylcarboxylic acid amide (co) polymer, especially PNVA, has a higher surface tackiness in a water absorbing state and a higher degree of bonding when dried than a conventional water absorbing agent. In addition, compared to (co) polymer of acrylic acid, it is excellent in light resistance, biodegradation resistance, etc., is stable, does not decrease water retention and tackiness during cultivation, and has a growth inhibitory effect on plants. Absent. Further, the crosslinked product of N-vinylcarboxylic acid amide (co) polymer is not found in ionic systems such as the conventional crosslinked product of sodium polyacrylate, which has a high liquid absorbing ability even in a high concentration salt-containing aqueous solution. There are features.

PNVA is a compound having at least two polymerizable unsaturated groups in one molecule (referred to as a "crosslinking agent"), N-vinylacetamide, and, if necessary, a copolymerizable monomer formed by radical polymerization under the absence of oxygen. It can be produced using a polymerization initiator. The polymerization process is not particularly limited, but aqueous solution polymerization, reverse phase suspension polymerization, and the like, which have been conventionally used as a method for producing a crosslinked product of sodium polyacrylate, can be employed. Specific examples thereof include JP-A-3-223304, It is described in JP-A-4-230250 and JP-A-4-346833. Specific examples of the crosslinking agent used in the production of the (co) polymer crosslinked product include N, N′-methylenebisacrylamide, triethylene glycol (meth) acrylate, pentaerythritol tri (meth) acrylate, divinylbenzene, N, N-alkylenebis (N-vinylacetamide) compounds (for example, N'-1,4-butylenebis (N
-Vinylacetamide), N, N'-diacetyl N,
N′-divinyl-1,3-bisaminomethylcyclohexane, etc.), pentaerythritol triallyl ether, tetraallyloxyethane, etc., and these can be used alone or in combination of two or more as needed. The amount of the crosslinking agent used is 2 × 10 ⁻⁴ to 10 mol%, preferably 5 × 10 ⁻⁴ to 2 mol%, based on the (co) polymerization component.
Mol% range. The polymerization initiator used in the production of the (co) polymer crosslinked product is a conventionally known peroxide, organic or inorganic peracid or a salt thereof, or an azobis compound alone or in combination with a reducing agent. Among them, azobis (2-amidinopropane) dihydrochloride, 2,2′-
An azobis-based initiator such as azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride. The amount of the polymerization initiator used is 0.0% based on the (co) polymerization component.
005 to 5 mol%, particularly preferably 0.005 to 0.5
Mol%. The polymerization initiation temperature is usually about -10 to 80C, and the reaction time is about 0.5 to 30 hours. The molar ratio of the N-vinylacetamide unit to the copolymerized monomer unit of the PNVA is preferably 100: 0 to 25:75. One or a mixture of two or more selected from the above ranges can be used as the liquid absorbing resin. The N-vinylcarboxylic acid amide (co) polymer or PNVA used for the seedling raising soil of the present invention includes:
The crosslinking density of PNVA is preferably 1/5000 to 1/10, more preferably 1/2000 to 1/50. Here, the crosslink density refers to a ratio of the number of crosslinked structural units (crosslink points) in the crosslinked polymer to the total number of structural units.
If the crosslink density is lower than 1/5000, sufficient water retention performance will not be exhibited, and if the crosslink density is higher than 1/10, the adhesive force for binding soil particles will be weakened, and the water retention performance will not be exhibited. Also, if the degree of crosslinking of PNVA contained in the combined soil is high, when the PNVA is swollen by adding water to the soil, the soil hardly fits into the inner surface of the pot.

In the present invention, the water absorption capacity of PNVA with respect to deionized water means the PNVA granule obtained by immersing PNVA granules in deionized water for at least one hour or more and impregnating the PNVA with deionized water until it is saturated. It is obtained as the ratio of the amount of water absorption to the weight (self-weight). P
The water absorption capacity of NVA with respect to deionized water is preferably 20 times or more, and more preferably 30 times or more.

The particle size of the crosslinked homopolymer or copolymer of N-vinylcarboxylic acid amide used in the present invention is preferably 0.05 to 5 mm,
5 to 1 mm is more preferable. When the particle size is smaller than 0.05 mm, so-called mamako is easily formed at the time of mixing with the soil, and it is difficult to mix with the soil. If the particle size is larger than 10 mm, the tackiness is undesirably reduced. The PNVA in the form of granules may contain a binder (film-forming substance), a bulking agent, a preservative, a bactericide, an insecticide, an antioxidant,
Deodorants, herbicides, soil pesticides, fertilizers, and the like can also be included or mixed. In the binding soil of the present invention, a water-soluble polymer may be used in addition to PNVA. Well-known polymers can be used as the water-soluble polymer, and the hardness of the soil can also be adjusted by using the water-soluble polymer in combination.

The content of the crosslinked homopolymer or copolymer of N-vinylcarboxylic acid amide in the seedling cultivation soil of the present invention is appropriately selected depending on the kind of cultivation soil and seedling.
It is preferably about 0.1 to 5.0% by weight, more preferably about 0.2 to 3% by weight. 0.1% by weight or less or 5.
When the content is 0% by weight or more, the adhesive strength is insufficient, and the soil particles of the cultivated soil are difficult to bind. In addition, the swelling of the crosslinked product that has absorbed water causes the soil to rise, which is not preferable in terms of plant growth. By adding a homopolymer cross-linked product or a copolymer cross-linked product of N-vinylcarboxylic acid amide in this range, there is no growth inhibitory effect on roots and water retention can be imparted, thereby promoting the growth of seedlings. Can be done.

The soil used in the present invention is a soil for cultivating plants, a soil mixture, a prepared soil,
It is not particularly limited as long as it is usually used, for example,
Includes garden soil, field soil, black soil, akadama soil, mulch, compost, peat moss, sand, river sand, hyuga stone, kanuma soil, Kiryu sand, Fuji sand, loam, vermiculite, perlite, etc., and mixtures thereof. Further, the soil may contain water, fertilizer, organic matter, pH adjuster, water-retentive substance, and the like. In addition, the soil used in the present invention may be powdery or granular, but in a combined state, in order to secure the permeability of the cultivated soil and prevent root rot, etc., the soil has an aggregated structure. It is preferable to use cultivation soil.

Next, the seedling raising method of the present invention will be described.
The seedling cultivation soil having the above configuration is filled in a seedling raising container. The container is not particularly limited, and a container for raising seedling such as a pot or a tray, a planter, a pot, or the like can be used. Next, the seedlings are sown and watered on the filled medium according to a usual cultivation method to grow seedlings. The type of seedling is not particularly limited, and the present invention is widely applied to vegetables, petals, seedlings, rice, and the like.

In the combined culture according to the present invention, the crosslinked homopolymer or copolymer of N-vinylcarboxylic acid amide absorbs and retains water by watering for cultivation of seedlings. Then, as the surrounding soil is dried, the water retained in the water retention layer is gradually released and diffused into the surrounding soil, preventing excessive drying and over-humidification of the soil, and containing moisture in the soil. The amount can be easily controlled to a range suitable for cultivation, and the management of irrigation is easy. When the seedlings are grown and transplanted, irrigation is stopped, the soil is dried and bonded to a strength sufficient to withstand the external forces during mechanical transplantation. That is, when the bottom surface of the pot is lightly pressed from the outside, it is necessary that the cultivated soil be removed from the pot without being collapsed in a state of being formed into the shape of the pot while holding the root of the seedling. The higher the degree of drying, the harder it becomes. However, it is sufficient to be able to transplant, and if it is too dry, it will adversely affect the growth. Therefore, the water content may be about 20% or less.
When the soil is dried and solidified, the seedlings are transplanted to a field or the like. Even after transplanting, the cultivated soil having a water retention function exists around the root of the seedling, so that the growth of the seedling is good.

[0019]

(Example) 500 g of a nice mat (trade name, manufactured by Mitsui Toatsu Fertilizer Co., Ltd.) having a water content of 9% was added to a PNVA (NA-15) having a saturated water absorption ratio of about 50 times by weight and a particle size of 100 to 300 μm.
And 5.0 g of Showa Denko Co., Ltd.) was added and mixed to prepare a cultivation soil for onion raising seedlings, which were filled into 160 seedling raising pots. Next, the seedling pot was irrigated with water and swelled with PNVA.
Seedlings were raised for days. When the seedlings had grown to a transplantable size, irrigation was stopped for one week and the soil was allowed to dry naturally. Then, when the bottom surface of the pot was lightly pressed from the outside, the seedling was able to be removed from the pot without disintegrating the cultivated soil in a state where the seedling was formed in a pot shape while holding the root portion. The root growth of the seedlings was good. Next, ten plants removed from the pot were selected and allowed to fall naturally from a height of 1 m, but none of the ten plants collapsed. The remaining seedlings could be mechanically transplanted to the field without disruption of the soil. After transplanting, the seedlings grew well, and there was no effect of the growth by stopping watering.

(Comparative Example) A soil for onion raising seedlings was prepared in the same manner as in Example 1 except that 5.0 g of Sumikagel S-50 (trademark, manufactured by Sumitomo Chemical Co., Ltd.) was used as the water-absorbing resin. The seedling raising pot was filled, and the onion was raised.
When the seedlings had grown to a transplantable size, irrigation was stopped for one week and the soil was allowed to dry naturally. Then, when the bottom surface of the pot was lightly pressed from the outside, the seedling was able to be removed from the pot without disintegrating the cultivated soil in a state where the seedling was formed in a pot shape while holding the root portion. Compared with the seedlings of the examples, both the root length of the seedlings and the amount of rooting on the cultivated soil were small. Then, 10 strains removed from the pot were selected and dropped naturally from a height of 1 m. As a result, collapse of the soil was observed in four strains.
The remaining seedlings had the same growth results as in the examples.

[0021]

As described above, the binding soil according to the present invention comprises a soil and a homopolymer crosslinked product of N-vinylcarboxylic acid amide of 0.1 to 5.0% by weight with respect to the soil. A cultivated soil obtained by mixing a copolymer crosslinked product with any one of an ionic and a nonionic monomer, wherein the particles constituting the soil are bound by drying from a water-absorbing state. Things. Since the binding soil of the present invention contains a crosslinked N-vinylcarboxylic acid amide (co) polymer as a water-retentive binder, it has high surface adhesiveness in a water-absorbing state, a high degree of binding when dried, and an acrylic resin. Compared with (co) polymers of acids, they are excellent in light resistance, biodegradation resistance and the like, are stable, do not decrease water retention and tackiness during cultivation, and have no growth inhibitory effect on plants.
Therefore, the use of the bondable soil of the present invention can provide seedlings having good rooting on the soil and a high survival rate, thereby shortening the cultivation period and increasing the yield.

Claims (3)

[Claims] 1. Soil and 0.1 to 5.0 relative to the soil
% Of N-vinylcarboxylic acid amide homopolymer or a crosslinked copolymer of ionic and nonionic monomers, and dried from a water absorbing state. Characterized in that particles constituting the soil are bound by the method. 2. The crosslinked product of a homopolymer of N-vinylcarboxylic acid amide or a copolymer crosslinked with any one of ionic and nonionic monomers is a crosslinked product of a homopolymer of N-vinylacetamide or It is a copolymer crosslinked product with any of ionic and nonionic monomers,
The crosslink density of the homopolymer crosslinked product of N-vinylacetamide or the crosslinked product of a copolymer with any one of ionic and nonionic monomers is 1/5000 to 1/10. 1. The bond culture according to item 1. 3. Filling the binding soil according to claim 1 or 2 into a container for raising seedlings, sowing and irrigating the binding soil to grow a cultivated plant, and then increasing the water content of the binding soil. A method for raising seedlings, comprising drying and solidifying the cultivated plant so as to have a concentration of 20% by weight or less, and transplanting the cultivated plant.