JP2002058339A - Culture soil for raising seedling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide culture soil for raising seedling, from which a root ball with high strength can be made, and allowing a user to smoothly carry out automatic transplantation using a transplanter. SOLUTION: This culture soil for raising seedling is obtained by formulating a culture soil base material with fusible fibers each having a fiber length of 0.5-2 mm, aspect ratio of 20-300, fiber moisture contant of <=10 wt.% based on the fiber mass, and the number of crimps of <=6/cm, and a method for hardening thus obtained culture soil by heating is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a soil for raising seedlings and a method for solidifying the same. More specifically, the present invention relates to a cultivation medium for raising seedlings, which forms a strong pot, and a solidification method thereof. The seedling cultivation soil of the present invention is particularly suitable to be used by filling a container for growing plants having a volume of 10 cm ³ or less, has a good filling property to the small container for growing plants, and furthermore, is capable of planting seedlings with a transplanter. It is possible to form a strong pottery which does not collapse sometimes.

[0002]

2. Description of the Related Art In Japan, labor saving and mechanization of agricultural work have been promoted with a decrease in the number of farmers and an aging farmer. As one of the methods, a method has been widely adopted in which a seedling grown in a small container is removed from the container together with a root pot with a transplanter and is automatically planted in a field. In the case of this method, "cell", "pot"
After automatically filling soil in a small container made of plastic or the like referred to as a plastic container or a tray provided by connecting the small containers, seeds of plants such as vegetables, flowers, fruit trees, and trees are seeded and raised for a predetermined period. Or cultivation with seeds is automatically stuffed into the small container or a tray connected to the small container, and then seedlings are raised for a predetermined period of time. This is commonly done. The root mortar is strong due to the self-adhesive strength of the cultivation and the entanglement of the roots of the plant, but maintains its shape, but the root mortar strength is low, the shape of the root mortar collapses with a slight impact,
It was difficult to plant seedlings using a transplanter.

[0003] Therefore, for the purpose of enabling planting by a transplanter, a method for improving the root pot strength of the cultivation for seedling raising has conventionally been proposed, and such a conventional technique includes vinyl acetate-acrylic acid. A mixture of ionic water-absorbing resin such as saponified methyl copolymer, sodium polyacrylate, vinyl alcohol-acrylic acid copolymer, etc. (Japanese Patent Application Laid-Open No. 58-31919). Known are ones in which a binder such as agar gel, bentonite, and starch are added (JP-A-5-7427), and those in which cellulose fibers having a length of 2 to 20 mm are added to cultivated soil (JP-A-8-130976). Have been. In the case of these conventional techniques, although a certain improvement in root mortar strength is recognized, its effect is not yet sufficient, and in order to further improve root mortar strength, it is necessary to use a large amount of the binder described above. However, the use of a large amount of the binder tends to cause a decrease in drainage of the cultivated soil, a decrease in plant cultivation ability, and an increase in cost.

[0004] For spinning or dry nonwoven fabric, fibers having a fiber length of 25 mm or more, a water content of less than 1% and a crimp number of 4 to 8 / cm are usually used. In general, non-crimped fibers having a fiber length of 3 to 20 mm and a moisture content of 15 to 30% are used.
Problems such as poor fiber dispersibility and insufficient strength after solidification are likely to occur.

[0005] Furthermore, in order to prevent cracking and collapse of the cultivation soil for raising seedlings, a heat-fusible core-sheath fiber is blended into the cultivation base material,
A seedling cultivation soil in which the sheath portion of the core-sheath type fiber is softened and adhered and solidified has been proposed (JP-A-11-113388, JP-A-2000-23561, etc.). However, even in the case of the conventional technique, when the seedlings are planted together with the root pots in a field or the like by the transplanter, the root pots may be cracked or collapsed, and the strength of the root pots is not always sufficient.
In the seedling cultivation soil used for a small plant cultivation container having a volume of 10 cm ³ or less, fiber clumps or the like that hinder the filling operation are not formed in the seedling cultivation soil, and the seedling cultivation soil has a good composition while maintaining a uniform composition. Filling with easy operability,
After filling, it is required that a strong pot is formed in the container, but this conventional technique for raising seedlings is not sufficiently considered because these points are not considered.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to form a high-strength root pot, and when the seedlings are planted together with the root pot in a field or the like by a transplanter, the root pot does not collapse and the plant is planted smoothly. Another object of the present invention is to provide a cultivation soil for raising seedlings capable of growing seedlings in a healthy manner without causing growth inhibition, and a method of solidifying the cultivation soil for raising seedlings. In particular, the present invention is suitable for mechanical filling into a small plant growing container having a volume of 10 cm ³ or less, a fiber mass that hinders filling is not formed, and fibers are uniformly dispersed in the seedling cultivation soil. Thus, the small plant growing container can be smoothly mechanically filled with good workability, and after filling into the plant growing container, a seedling cultivation soil capable of forming a strong root pot, and An object of the present invention is to provide a method for solidifying the seedling culture soil.

[0007]

The present inventors have intensively studied to achieve the above object. As a result, a specific heat-fusible fiber, that is, a fiber length of 0.5 to 2 mm, an aspect ratio of 20 to 300, a fiber moisture content of 10% or less based on the fiber mass, and a 6 /
cm or less, a heat-fusible fiber is mixed to prepare a seedling culture medium, and the heat-fusible fiber blended into the seedling culture medium is melt-bonded by heat treatment of the seedling culture medium. It was found that a pot was formed. Then, the resulting culture for raising seedlings is particularly suitable as a culture for growing cell seedlings used for planting with a transplanter or the like, and the root pot does not collapse at the time of planting with the transplanter, and the planting work can be performed smoothly. Was found. In particular, the seedling cultivation soil containing the specific heat-fusible fiber described above has a volume of 10 cm.
^It is suitable for use in a small plant growing container of ³ or less, and can be filled with good operability while maintaining a uniform composition in the small plant growing container. It has been found that an excellent root mortar is formed. Furthermore, the present inventors have found that the above-mentioned soil for raising seedlings can grow seedlings soundly and do not cause growth inhibition, and completed the present invention based on those findings.

That is, the present invention provides: (1) a cultivation material having a fiber length of 0.5 to 2 mm, an aspect ratio of 20 to 300, and a fiber moisture content of 1 to fiber mass;
A cultivation soil for raising seedlings, characterized by containing heat-fusible fibers having 0% or less and a crimp number of 6 / cm or less.

The present invention further provides: (2) the seedling cultivation soil of (1), which is a seedling cultivation soil for use in a container for cultivating a plant having a volume of 10 cm ³ or less; (1) A heat-fusible composite spun fiber and / or mixed spun fiber comprising a fiber-forming polymer and a thermoplastic polymer having a melting point or softening point lower than that of the fiber-forming polymer by 20 ° C. or more. ) Or (2)
(4) The above-mentioned (1), wherein the cultivation base material is a cultivation base material mainly composed of peat moss and / or perlite together with soil.
(5) The cultivation soil for raising seedling according to any one of (1) to (4), wherein the blending ratio of the cultivation base material and the heat-fusible fiber is 99: 1 to 85:15 in mass ratio. (6) Any one of the above-mentioned (1) to (5) wherein the heat-fusible fiber is melt-adhered in the seedling culture; (7) The following formula (I) ) Is required to be 30 mN or more, and the following formula (I
The seedling cultivation soil according to the above (6), which satisfies at least one of the requirements that the amount of deflection determined by I) is 5 or more;

[0010]

## EQU2 ## Flexural strength (mN) = {(50.times.B) / (25.times.A)}. Times.3 / 2 (I) Deflection amount = C / A (II) 500g /
m ² sheet-shaped material, and then heat-treated to melt and bond the heat-fusible fibers in the seedling culture soil to obtain a sheet-shaped material having a length of 100 mm and a width of 25 mm. Indicates the thickness (mm) of the test piece when a pressure of 53.9 kPa is applied to the entire upper surface of the test piece, and B indicates that the both ends of the test piece are placed on the left and right support bases separated by a distance of 50 mm. Is fixed, and the area of 2 cm ²
Is placed at a speed of 10 mm / min and lowered, and the load (maximum load) (mN) applied to the test piece when the test piece is damaged is shown. Indicates the deflection depth (mm). (8) By heat-treating the seedling cultivation soil, the heat-fusible fibers in the seedling cultivation soil are melt-bonded to obtain a density of 0.10 g / c.
A molded product formed to have m ³ was used as a test piece, and a circular pressure plate having an area of 2 cm ² was placed on the center of the test piece to obtain a test piece.
Lower at a speed of 0 mm / min.
(6) or (7), wherein the compressive stress at the time of lowering is 10 kN or more.

Further, the present invention provides: (9) Filling the cultivation soil for seedling raising of the above (1) to (5) into a container for cultivating a plant, irrigating and heating, and heat-fusing the fibers in the cultivation soil. This is a method for solidifying the cultivation soil for raising seedling, which is characterized by being melt-bonded.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The seedling cultivation medium of the present invention comprises a cultivation base material and heat-fusible fibers. As the heat-fusible fiber, the heat-fusible fiber is mixed or melted or softened when heat-treated for the seedling culture containing heat-fusible fiber, and the heat-fusible fiber adheres to the medium. Any material may be used as long as it adheres to the components therein and has the specific fiber length, aspect ratio, fiber moisture content, and number of crimps described above. Among them, the heat-fusible fiber maintains the fiber shape even after the heat treatment and maintains the fusion state between the fibers and the fusion state between the fiber and the components in the cultivation base material. It is preferable because a high root can be formed. for that reason,
As the heat-fusible fiber, a fiber-forming polymer (first component) having a high melting point or softening point capable of maintaining a fiber form even after being subjected to a heat treatment, and at least 20 ° C. lower than the fiber-forming polymer Thermoplastic polymer having a melting point or softening point (second
Component), a composite spun fiber and / or a mixed spun fiber is preferably used, and a composite spun fiber is more preferably used. In the composite spun fiber and the mixed spun fiber, at least a part of the fiber surface, preferably 80% or more of the fiber surface, is formed of a thermoplastic polymer (second component) having a low melting point or a low softening point. Preferably, in this case, the heat treatment allows the fibers to be melt-bonded (bonding between the fibers and bonding between the fibers and the components in the cultivation base material) satisfactorily, thereby forming a strong pot.

Examples of the fiber-forming polymer (first component) constituting the composite spun fiber and the mixed spun fiber include polyester such as polyethylene terephthalate and polybutylene terephthalate, polyamide, polypropylene, polyvinyl chloride and polyvinyl chloride. Mention may be made of fiber-forming polymers having a high melting point or softening point, such as vinylidene. Further, the thermoplastic polymer (second component) having a low melting point or low softening point has a melting point or softening point which is lower than that of the polyester or polyamide used as the first component by two.
A thermoplastic polymer having a temperature of 0 ° C. or lower, such as a modified polyester (eg, a copolymerized polyester), a modified polyamide (eg, a copolymerized polyamide), polyethylene, an ethylene-vinyl acetate copolymer, or an ethylene-propylene copolymer can be given. . Composite spun fibers or mixed spun fibers are
It can be formed by combining one or more of the appropriate first component polymer and one or more of the appropriate second component polymer. As the polymer for the second component, a thermoplastic polymer having a melting point or a softening point of 130 ° C. or less is preferably used because the fusion bonding of the heat-fusible fibers can be performed smoothly.

As is well known, a conjugate spun fiber is formed by joining two or more polymers with each other in a continuous state without interruption in the length direction of the fiber to form one fiber (composite fiber). Generally, the composite form is classified into a core-sheath type, a lamination type (side-by-side type) or a mixed type thereof in view of the cross-sectional shape of the fiber. The composite form of the composite spun fiber used in the present invention,
Any of them may be used without any particular limitation. Among them, a core-sheath type having a low melting point or low softening point thermoplastic polymer (second component) as a sheath component and a high melting point or high softening point fiber-forming polymer (first component) as a core component. The conjugate spun fiber is preferably used because the entire surface is formed from the second component having a low melting point or a low softening point and has excellent melt adhesion. A mixed spun fiber is a fiber formed by mixing and spinning two or more polymers that are not uniformly mixed with each other at a stage before spinning from a spinneret. One or two or more of
It is a fiber forming the fiber of the book, and the cross section of the fiber generally has a sea-island structure in many cases, and may have a laminated structure in some cases. As the mixed spun fiber, a mixed spun fiber in which a thermoplastic polymer (second component) having a low melting point or a low softening point forms a sea component, and a fiber forming polymer having a high melting point or a high softening point forms an island component. Is preferably used because of its excellent melt adhesion.

The cross-sectional shape of the heat-fusible fiber used in the present invention is not particularly limited. For example, any cross-section such as a round shape, a triangular shape, a T-shape, a flat shape, a multi-leaf shape, a V-shape, and a hollow shape can be used. It may be shaped.

The heat-fusible fiber used in the present invention must have a fiber length of 0.5 to 2 mm.
1.5 mm, preferably 0.8 to 1.2 mm
Is more preferable. When the fiber length of the heat-fusible fiber is less than 0.5 mm, a strong strong root mortar is not formed. In addition, the workability when cutting the fiber length to less than 0.5 mm becomes extremely poor, the productivity is reduced, and the cost is extremely high. On the other hand, when the fiber length of the heat-fusible fiber exceeds 2 mm, a fiber lump is formed and is not uniformly dispersed when blended with the culture soil base material. Filling by machine becomes difficult. In particular, when filling into a small plant growing container having a volume of 10 cm ³ or less, if the fiber length of the heat-fusible fiber exceeds 2 mm and fiber clumps are generated, the small plant growing container is used for raising seedlings. The soil is not smoothly filled by a machine or the like, and even if the soil is filled in the container for growing plants, the dispersion of fibers in the soil for raising seedlings is not uniform, so that a strong root pot is not formed. Conventionally, so-called shortcut fibers cut into short fiber lengths have been sold for papermaking or for wet nonwoven fabrics. However, the fiber lengths of these commercially available shortcut fibers are usually 3 mm or more and extremely 2 mm or less. Not short fiber length. The reason is that if the cut length of the fiber is less than 3 mm, the entanglement between the fibers is reduced and the strength of the paper or nonwoven fabric is reduced. If the cut length is shorter than 3 mm, it takes time and time to cut the fiber. That there is no demand for ultra-short fibers having a fiber length of less than 3 mm, and that conventional cutting machines are not designed to produce ultra-short fibers of less than 3 mm And the like.

Further, the heat-fusible fiber used in the present invention is:
The aspect ratio needs to be 20 to 300,
Preferably it is 50-100. When the aspect ratio of the heat-fusible fiber is less than 20, it is not possible to form a high-strength root mortar. On the other hand, when the aspect ratio exceeds 300, a fiber mass is formed in the cultivation substrate, and the container for plant growth, especially the volume of 10 cm ³ Poor filling of the following small plant growing containers, lowering of root pot strength, etc. occur. In this specification, the aspect ratio of the heat-fusible fiber refers to a value obtained by dividing a fiber length by a fiber diameter (outer diameter of the fiber). The fineness of the heat-fusible fiber is from 0.1 to 10 dtex, particularly from 1 to 5 in view of dispersibility and adhesiveness.
About dtex is preferable.

The moisture content of the heat fusible fiber used in the present invention must be 10% or less, preferably 7% or less, and preferably 3% or less based on the mass of the heat fusible fiber. It is more preferred that: When the moisture content of the heat fusible fiber exceeds 10%, the heat fusible fiber does not split into single yarns when mixed with the cultivation base material, and is not uniformly dispersed in the cultivation base material. Root mortars with high density are not formed.

The heat-fusible fiber used in the present invention may be either crimped or not crimped, and the number of crimps is 6 / cm or less (about 15 / inch or less). ), That is, 0 to 6 / cm. When the number of crimps of the heat-fusible fiber exceeds 6 / cm, a fiber mass is formed when mixed with the cultivation base material, and the container for growing plants, particularly, the volume of 10
Filling into a small plant growing container having a size of ³ cm or less becomes difficult, and the heat-fusible fibers are not uniformly dispersed in the cultivation base material. If the heat-fusible fibers have some crimps, the heat-fusible fibers can easily contact and fuse with each other in the seedling cultivation medium, and the strength of the seedling cultivation medium is improved. The fusible fibers preferably have a crimp of about 1 to 4 fibers / cm.

There is no particular limitation on the type of soil substrate used for the seedling culture of the present invention, and the same materials as those used in the related art can be used according to the type of plant to be grown. Among them, in the present invention, heavy clay, vegetation,
So-called soil (natural soil) such as vegetation soil, loam; organic materials such as peat moss, park compost, lignite, peach, charcoal, and coal powder; and at least one inorganic material such as perlite, vermiculite, rock wool, and zeolite Is preferred. Among them, inexpensive and good handleability, from the point that it is easy to take out from the container for growing plants, together with the soil, a soil culture substrate containing at least one of peat moss and pearlite as a main component is preferably used,
A soil cultivation base material obtained by mixing both peat moss and pearlite in soil is more preferably used. In preparing the seedling cultivation soil, a humectant such as a polyethylene glycol-based humectant, or a fertilizer such as an inorganic fertilizer, an organic fertilizer, or a chemical compost may be further added. For example, by adding vermiculite or a wetting agent, drainage and heat retention can be properly adjusted, and the fertilizer contributes to the growth of seeds and seedlings. Preferable examples of the soil cultivation base material include a soil cultivation base material in which an organic material such as peat moss, an inorganic material such as perlite or vermiculite, a wetting agent, and a fertilizer are mixed with the natural soil as described above. Generally, soil 1
100 parts by mass of natural materials such as peat moss
８００800 parts by mass, 10-500 parts by mass of an inorganic material such as perlite or vermiculite, 0.1-1 part by mass of a wetting agent, and 0.1-2 parts by mass of a fertilizer.

In the cultivation medium for seedling raising of the present invention, the mixing ratio of the cultivation base material and the heat-fusible fiber is 99: 1 to 85:15 by mass.
Is preferably 98: 2 to 90:10, and more preferably 97: 3 to 95: 5. If the blending ratio of the heat-fusible fiber is less than 1% by mass based on the total mass of the seedling cultivation soil, sufficient root mortar strength cannot be obtained, and the root mortar shape is likely to collapse with a slight impact or external force. On the other hand, if it exceeds 15% by mass, a fiber mass is formed when the heat-fusible fiber and the cultivation base material are mixed, and the heat-fusible fibers are not uniformly dispersed in the cultivation base material. In addition, it is difficult to smoothly pack the soil into a plant growing container such as a seedling box, and the cost is increased.

The cultivation soil for raising seedlings of the present invention is distributed and sold in a state where the cultivation base material and the heat-fusible fibers are simply mixed without being subjected to a heat treatment for melting and bonding the heat-fusible fibers. After the (user) packs it into a plant growing container such as a cell, a pot, a tray, or a seedling box, it may be subjected to a heat treatment so that the heat-fusible fibers are melt-bonded to solidify the soil. Alternatively, the soil for raising seedlings of the present invention may be packed in a container for growing plants such as cells, pots, trays, and seedling boxes, heat-treated and solidified, and then sold and sold. In some cases,
After filling the medium for raising seedlings of the present invention into a relatively large box or the like and performing a heat treatment, the cells are cut into cells, pots, trays, and suitable sizes that can be packed into a container for growing plants such as a seedling box. It may be packed in a container for growing plants while keeping its shape. However, regardless of whether the heat treatment is performed by the seller or the purchaser (user) of the seedling cultivation soil of the present invention, the seedling cultivation soil of the present invention is grown in plants such as cells, pots, trays, and seedling boxes. It is desirable to heat-treat after packing in a container.

As a container for cultivating a plant for cultivating the seedling cultivation soil of the present invention, the same cells, pots, trays and seedling boxes as those conventionally used can be used. Shape, structure, size, etc. can be selected appropriately according to each situation, but the seedling cultivation soil of the present invention, when used by filling a small plant cultivation container having a volume of 10 cm ³ or less, Demonstrate its excellent effect.
In the present invention, the fiber length of the heat-fusible fiber blended in the seedling culture medium has a fiber length of 0.5 to 2 mm and an aspect ratio of 20 to 30.
0, when the moisture content of the fiber is 10% or less based on the mass of the fiber and the number of crimps is 6 / cm or less, the heat-fusible fiber is uniformly dispersed without forming a fiber mass in the cultivation for raising seedlings. Therefore, even if it is a small container for growing a plant, the soil for growing a seedling can be mechanically filled into the container for growing a plant with good operability without clogging or the like. Moreover, since the heat-fusible fibers are uniformly dispersed in the seedling cultivation soil, a heat treatment after filling forms a root pot having high strength. Volume is 10c
As the container for growing plants of m ³ or less, any container can be used as long as it has a volume of 10 cm ³ or less, but generally, the upper hole diameter of the container is 10 to 40 mm.
A container for growing plants having a depth of 10 to 60 mm and a volume of 1 to 10 cm ³ is preferably used, and the upper hole diameter is 12 to 30 m.
m, a depth of 15 to 50 mm, and a volume of ³ to 9 cm ³ for growing plants is preferably used. Various types of such plant growing containers have been conventionally commercially available [for example, “POT448” (trade name) manufactured by Minoru Sangyo Co., Ltd.)
Many are commercially available such as “POT324” (trade name)]. The seedling cultivation soil of the present invention can be effectively used for any of such conventional commercially available small-volume plant growing containers.

In using the cultivation soil for raising seedlings of the present invention,
Although not limited in any way, for example, the cultivation soil for seedling raising of the present invention is put in a soiling box of an automatic sowing machine, and it is placed in a pot seedling box as described in, for example, JP-T-5-508994. After filling (filling soil), a pot seedling box is irrigated and then subjected to a heat treatment, and the cultivation soil for raising seedlings of the present invention is applied to an automatic pot sowing machine “LSP” manufactured by Minoru Sangyo Co., Ltd.
E-4 "and put it in a pot seedling box (Minoru Sangyo Co., Ltd." pot 448 seedling box "), fill it with water, fill it with water, and heat it. A method of performing processing or the like can be adopted. By applying heat treatment to the seedling cultivation soil of the present invention to melt or soften the heat fusible fibers blended in the seedling cultivation soil, adhesion between the heat fusible fibers, and heat fusible fibers And the components in the culture medium are adhered to each other, forming a three-dimensional mesh-like reinforcing structure in the culture medium for seedling, solidifying the culture medium for seedling growth, increasing its shape retention, and increasing the strength of the root pot. Granted.

The heat treatment of the seedling cultivation soil may be performed directly without watering the seedling cultivation soil, but it is preferable to heat the seedling cultivation soil after irrigating the soil. When heat treatment is performed after watering the seedling cultivation soil, the heat-fusible fibers contained in the seedling cultivation medium can be melt-bonded uniformly in a short period of time, and the solidification has a uniform and strong overall strength. An object (root bowl) is formed. Moreover, the seeds of the plant can be directly sown on the irrigated soil for raising seedlings after the heat treatment, and the seedlings can be raised. The degree of irrigation during the heat treatment can be adjusted according to the soil cultivation base material constituting the seedling cultivation soil, the type of heat-fusible fiber, the composition of the seedling cultivation soil, the water content of the seedling cultivation soil itself, etc. In general, it is preferable to irrigate the water to such an extent that a saturated state (a water-containing state equal to or higher than the capillary disconnection point) is obtained.
The heat treatment temperature can be selected according to the melting point or softening point of the heat-fusible component in the heat-fusible fiber. It is preferable to carry out the reaction at a temperature higher by ° C. The method and apparatus for heating are not particularly limited, and any method and apparatus can be used as long as it can uniformly heat the entire cultivation medium for seedling raising to a predetermined temperature. When the heat treatment is performed at a temperature of 100 ° C. or more, it is preferable to perform the heat treatment using an autoclave.

The characteristics of the seedling cultivation soil of the present invention, such as the strength and flexibility, include the type of seedling to be grown in the seedling cultivation, the root prosperity of the seedling itself, the size of the plant growing container, the type of transplanter, and the like. In general, in a culture for raising seedlings obtained by heat-treating and heat-bonding the heat-fusible fibers, the bending strength determined by the above formula (I) is 30.
mN or more, or the amount of deflection determined by the above formula (II) is 5 or more, or 30
It is preferable to satisfy the characteristics of both the bending strength of mN or more and the deflection amount of 5 or more, and it is more preferable to satisfy both. In particular, in the soil for raising seedlings of the present invention after the heat treatment, the above-mentioned bending strength is more preferably 50 mN or more, and further preferably 100 mN or more. Further, the above-mentioned deflection amount is more preferably 10 or more, and further preferably 15 or more. If the bending strength of the seedling cultivation soil after the heat treatment is less than 30 mN, the root mortar strength is insufficient, and the handleability at the time of planting operation with a transplanter or the like tends to be reduced. In addition, if the amount of bending of the seedling culture medium after the heat treatment is less than 5, the seedling culture medium is too hard, and the growth of seedlings is liable to occur.

Further, the cultivation medium for seedling raising of the present invention is formed by heat-treating the cultivation medium for raising seedlings so that the heat-fusible fibers in the cultivation medium for raising seedlings are melt-bonded to have a density of 0.10 g / cm ^3. When a circular pressure plate having an area of 2 cm ² is placed on the center of the test piece and lowered at a speed of 10 mm / min, the compression stress when the circular pressure plate drops by 5 mm becomes It is preferably at least 10 kN,
It is more preferably at least 20 kN, even more preferably at least 25 kN. This compressive stress is 10 kN
When the ratio is less than the above range, collapse of the root mortar due to a decrease in root mortar strength, and reduction in workability at the time of planting operation using a transplanter or the like are likely to occur.

The seeding of the seedling cultivation soil of the present invention may be carried out before the heat treatment as long as the seeds can withstand the heating temperature during the heat treatment. It is preferable to sow the seed after performing the fusion bonding of the heat-fusible fiber. If the seeds are sown before the heat treatment, the high temperature during the heat treatment causes the seeds to deteriorate, die, etc., and often does not germinate.
In the case where the heat treatment is performed after watering the seedling culture medium, the seeds can be directly sown without watering the seedling culture medium in the irrigated state after the heat treatment again. However, if necessary, additional watering may be performed at the time of sowing. The seedling cultivation soil of the present invention can be used not only for sowing seeds but also for cuttings and the like. Cutting may be performed on the seedling cultivation soil and handled in the same manner as when sowing.

[0029] Plants suitable for sowing on the seedling cultivation soil of the present invention before solidification or on the seedling cultivation soil after solidification (for example, seedling raising cells) include, for cut flower applications, snapdragon, bupreulum and eustoma. , Stock, Anemone, Campanula, Dahlia, Scapiosa, Delphinium, Larkspur, Nigella, Hanashinobu, Blue lace flower, Matricaria, Shinteppoi lily, Limonium sinuata, Oxypetalum, Classpedia,
Ligustrum and the like. For potted plants, seedlings, flowerbeds, use for agelatam, isotoma, impatiens, exacum, gerbera, gazania, calseoraria, chrysanthemum, coleus, salvia, sizansus, cineralia, geranium, torenia, pansy, vinca, primula, petunia, beconia, marigold , Ranunculus, carnation and the like. Vegetable cell seedling applications include celery, beet, leek, onion, leek,
Cabbage, kohlrapi, cabbage, cauliflower, broccoli, Chinese cabbage, Tsukena, sesame, chard, chungig, honeysuckle, perilla, spinach, lettuce, asparagus, parsley, endive, leek and the like. Fruit vegetable cell seedling applications include melon, peppers, cucumber, watermelon, pumpkin, gangan, kinshiuri, tomato, eggplant, okra, sweet corn, kidney bean, pea, edamame, broad bean, and the like. In addition, as a plant suitable for cutting on the seedling cultivation soil of the present invention before solidification, or on the seedling cultivation soil of the present invention after solidification (plug for seedling raising), it can be propagated on cuttings such as chrysanthemum, carnation, and gypsophila. Plants. As the cultivation base material, as described above, peat moss and / or
Or, those mainly based on perlite are suitable, but for cut flower use, flower bed use, vegetable cell seedling use, fruit vegetable cell seedling use, soil and peat moss-based cultivation base material is particularly suitable, and cutting A soil cultivation base material mainly composed of soil and perlite is particularly suitable for the growth of plants adapted to the above conditions.

[0030]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited to the following examples. In the following examples, the evaluation of the root pot strength and the measurement of the bending strength, the amount of deflection, and the compressive stress of the soil for raising seedlings were performed as follows.

(1) Root mortar strength: The root mortar (root mortar before sowing) formed in the following Examples or Comparative Examples was dropped from a height of 1 m and was evaluated according to the following four-level evaluation criteria. The score was evaluated. [Evaluation Criteria] 1 point: The root mortar was broken apart. 2 points: 5-8 root mortars were broken. 3 points: Root mortar broken into 2-4 pieces. 4 points: No cracks occurred in the root mortar.

(2) Flexural strength and amount of bending of the seedling cultivation soil: (i) The seedling cultivation soil has a basis weight of 500 g / m ² on a base.
The sheet is placed in a sheet (flat) and water is sprayed (irrigation) at a rate of 100 cc / m ² , and then the base is put into an autoclave and employed in the following examples or comparative examples. The heat treatment was performed at the temperature and for the specified time (115 ° C. for 15 minutes). After being taken out of the autoclave, the heat-treated sheet-like seedling culture soil was cut into a test piece a having a length of 100 mm and a width of 25 mm, and a pressure of 53.9 kPa was applied from the entire upper surface of the test piece a at that time. The thickness A (mm) of the test piece a was measured. (Ii) Next, as shown in FIG. 1, the test piece a of the above (i) is placed on the left and right support bases 1a, 1b arranged at a distance of 50 mm, and both ends a ₁ , After a ₂ is fixed by the end fixing means 2a and 2b, a circular pressure plate 3 having an area of 2 cm ² is placed on the center of the test piece a and 10 mm / min.
When the test piece a was broken, the load (maximum load) B (mN) applied to the test piece a when the test piece a was broken was read, and the deflection depth C (mm) at that time was read. The bending strength and the amount of flexure were calculated by (I) and equation (II), respectively.

[0033]

(3) Flexural strength (mN) = {(50 × B) / (25 × A)} × 3/2 (I) Deflection amount = C / A (II)

(3) Compressive stress of seedling cultivation soil: A seedling cultivation soil is filled in a vat-shaped container so as to have a density of 0.10 g / cm ^3, and this is heated at 95 ° C. for 90 minutes. The heat-fusible fiber in the cultivated soil is melt-bonded to form a flat molded product (length x width x thickness = 300 mm x 300 mm x 3).
0 mm), and this molded product was used as a test piece. A circular pressure plate having an area of 2 cm ² was placed on the center of the test piece to form a test piece.
It was lowered at a speed of mm / min, and the compression stress when the circular pressure plate was lowered by 5 mm was measured.

The contents and abbreviations of the heat-fusible fibers used in the following Examples and Comparative Examples are as follows. In addition,
In the following heat-fusible fibers, a cutting operation for obtaining fibers having a predetermined fiber length is performed using a guillotine cutter (manufactured by Onouchi Seisakusho), using a tow having a toe fineness of 1000 ktex, and a shot speed of 150 shots / min. Was performed under the following conditions. ○ Heat-fusible fiber: core-sheath type composite fiber composed of polyethylene terephthalate as a core component and polyethylene terephthalate copolymerized with 45 mol% isophthalic acid [mass ratio of core component: sheath component = 1: 1, melting point of sheath component] = 110
° C, melting point of core component = 260 ° C, single fiber fineness = 1.7 dt
ex; fiber length = 1 mm, aspect ratio = 80, moisture content =
10%, number of crimps = 0 / cm (non-crimped)] Heat-fusible fiber: core-sheath type composite fiber composed of polyethylene terephthalate as a core component and 45 mol% copolymerized polyethylene terephthalate as an isophthalic acid sheath component [ Mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110
° C, melting point of core component = 260 ° C, single fiber fineness = 3.3 dt
ex; fiber length = 2 mm, aspect ratio = 115, water content = 10%, number of crimps = 0 / cm (non-crimp)] heat-fusible fiber: polyethylene terephthalate as core component and isophthalic acid as sheath component Core-sheath type composite fiber composed of 45 mol% copolymerized polyethylene terephthalate [mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110]
° C, melting point of core component = 260 ° C, single fiber fineness = 1.7 dt
ex; fiber length = 1 mm, aspect ratio = 80, moisture content =
0%, number of crimps = 0 / cm (non-crimped)] Heat-fusible fiber: core-sheath type composite fiber composed of polyethylene terephthalate as a core component and 45 mol% copolymerized polyethylene terephthalate as an isophthalic acid [ Mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110
° C, melting point of core component = 260 ° C, single fiber fineness = 1.7 dt
ex; fiber length = 1 mm, aspect ratio = 80, moisture content =
0%, number of crimps = 2.8 / cm] Heat-fusible fiber (powder): core-in-sheath type conjugate fiber composed of polyethylene terephthalate as the core component and polyethylene terephthalate copolymerized with 45 mol% isophthalic acid as the sheath component (Powder) [mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110 ° C., melting point of core component = 260 ° C., single fiber fineness = 3.3 dtex; fiber length = 0.3 mm, aspect ratio Ratio = 17, water content = 10%, number of crimps = 0 / cm (non-crimped)] ○ heat-fusible fiber: polyethylene terephthalate as the core component and 45 mol% isophthalic acid as the sheath component. Core-sheath type composite fiber [mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110]
° C, melting point of core component = 260 ° C, single fiber fineness = 2.2 dt
ex; fiber length = 5 mm, aspect ratio = 340, moisture content = 15%, number of crimps = 0 / cm (non-crimped)] ○ heat-fusible fiber: polyethylene terephthalate as the core component and isophthalic acid as the sheath component Core-sheath type composite fiber composed of 45 mol% copolymerized polyethylene terephthalate [mass ratio of core component: sheath component = 1: 1, melting point of sheath component = 110]
° C, melting point of core component = 260 ° C, single fiber fineness = 2.2 dt
ex; fiber length = 5 mm, aspect ratio = 340, moisture content = 0%, number of crimps = 7.9 / cm]

Further, the contents of the base material used in the following Examples and Comparative Examples are as follows. ○ Cultivation substrate : 100 parts by mass of soil (Akadama soil) with peat moss 2
To 100 parts by mass of a mixture obtained by mixing 0 parts by mass and 10 parts by mass of vermiculite, 0.01 part by mass of a wetting agent (polyethylene glycol) and a fertilizer ("Low-grade chemical fertilizer Asahi Micro" manufactured by Chisso Asahi Fertilizer Co., Ltd.) Porous ”) was blended at a ratio of 0.5 parts by mass to obtain a cultivated soil base material.

Example 1 (1) 95 parts by mass of the cultivation base material and 5 parts by mass of the heat-fusible fiber were placed in a mixer container and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 1. (3) The remaining portion of the seedling cultivation obtained in the above (1) was used as a pot automatic seeder “LSP” manufactured by Minoru Sangyo Co., Ltd.
E-4 "and put it in a pot seedling box [Minoru Sangyo Co., Ltd." pot 448 seedling box "(volume =
4.1 cm ³ , upper hole diameter = 16 mm, depth 25 mm)]
After automatic filling (filling with soil), the pot seedling box was irrigated at a rate of 2 ml / 1 pot, and heat-treated at 110 ° C. for 15 minutes in an autoclave. When the root mortar strength of the obtained root mortar was evaluated by the method described above,
It was as shown in Table 1 below. (4) The bupreulum seeds are added to the seedling cultivation soil in the pot after the heat treatment obtained in the above (3) in an amount of 1 per pot.
Sow at a rate of 15 to 20 ° C and a humidity of 50 to
The seedlings are grown under a condition of 70% until the height becomes about 2-3 cm (grown for about 15 days), and the seedlings are used using a transplanter (“Vegetable transplanter OP-4” manufactured by Minoru Sangyo Co., Ltd.). When the root mortar was removed from the pot and transplanted into the field, the root mortar did not collapse at the time of transplantation, and the handleability was excellent.

Example 2 (1) 90 parts by mass of the cultivation base material and 10 parts by mass of the heat-fusible fiber were placed in a mixer vessel and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 1. (3) The remaining part of the seedling cultivation soil obtained in the above (1) was potted with a pot seedling box (“Pot 44 manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as in (3) of Example 1.
8 seedling boxes "), the pot seedling boxes were irrigated at a rate of 2 ml / 1 pot and heat-treated at 110 ° C. for 15 minutes in an autoclave. The root mortar strength of the resulting root mortar was evaluated by the method described above, and was as shown in Table 1 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were taken out of the pot and transplanted into a field. The roots did not collapse at the time of transplantation. It was excellent.

Example 3 (1) 95 parts by mass of the above-mentioned cultivation base material and 5 parts by mass of the heat-fusible fiber were placed in a mixer container, and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 1. (3) The remaining part of the seedling cultivation soil obtained in the above (1) was potted with a pot seedling box (“Pot 44 manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as in (3) of Example 1.
8 seedling boxes "), the pot seedling boxes were irrigated at a rate of 2 ml / 1 pot and heat-treated at 110 ° C. for 15 minutes in an autoclave. The root mortar strength of the resulting root mortar was evaluated by the method described above, and was as shown in Table 1 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were taken out of the pot and transplanted into a field. The roots did not collapse at the time of transplantation. It was excellent.

Example 4 (1) 95 parts by mass of the cultivation base material and 5 parts by mass of the heat-fusible fiber were placed in a mixer container and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 1. (3) The remaining part of the seedling cultivation soil obtained in the above (1) was potted with a pot seedling box (“Pot 44 manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as in (3) of Example 1.
8 seedling boxes "), the pot seedling boxes were irrigated at a rate of 2 ml / 1 pot and heat-treated at 110 ° C. for 15 minutes in an autoclave. The root mortar strength of the resulting root mortar was evaluated by the method described above, and was as shown in Table 1 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were taken out of the pot and transplanted into a field. The roots did not collapse at the time of transplantation. It was excellent.

<< Comparative Example 1 >> (1) Only the above-mentioned cultivation base material was used as a cultivation medium for raising seedlings without blending heat-fusible fibers. (2) The bending strength and the amount of bending of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by using the part of the cultivation soil for seedling raising of the above (1) by the method described above. Was as shown in FIG. (3) The remaining portion of the seedling cultivation soil of the above (1) was potted with a pot seedling box (“Pot 448 seedling box” manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as (3) of Example 1. ) Automatically fills the pot with seedlings,
Water was irrigated in a volume of 1 ml / pot and it was heat-treated at 110 ° C. for 15 minutes in an autoclave. The root mortar strength of the obtained root mortar was evaluated by the above-described method, and the results were as shown in Table 2 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were raised from the pot and the seedlings were pulled out of the pot and transplanted into a field. Cultivation was not carried out.

Comparative Example 2 (1) 85 parts by mass of the cultivation base material and 15 parts by mass of the heat-fusible fiber were placed in a mixer vessel and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 2. (3) After the remaining portion of the seedling cultivation soil obtained in the above (1) was automatically packed in a pot seedling box using an automatic pot sowing machine in the same manner as in (3) of Example 1, This pot seedling box (“Pot 448 seedling box” manufactured by Minoru Sangyo Co., Ltd.)
Was irrigated at a rate of 2 ml / 1 pot, which was heat-treated in an autoclave at 110 ° C. for 15 minutes. The root mortar strength of the obtained root mortar was evaluated by the above-described method, and the results were as shown in Table 2 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were raised from the pot, and the roots were pulled out of the pot and transplanted to the field. Could not be carried out smoothly, so that subsequent cultivation was not carried out.

Comparative Example 3 (1) 95 parts by mass of the cultivation base material and 5 parts by mass of the heat-fusible fiber were placed in a mixer vessel and stirred to prepare cultivation for seedling raising. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 2. (3) The remaining part of the seedling cultivation soil obtained in the above (1) was potted with a pot seedling box (“Pot 44 manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as in (3) of Example 1.
8 seedling boxes "), the pot seedling boxes were irrigated at a rate of 2 ml / 1 pot and heat-treated at 110 ° C. for 15 minutes in an autoclave. The root mortar strength of the obtained root mortar was evaluated by the above-described method, and the results were as shown in Table 2 below. (4) Bupreulum seeds are sown on the seedling cultivation soil in the pot after the heat treatment obtained in (3) in the same manner as in (4) of Example 1 so that the height of the seedlings becomes about 2-3 cm. Using the same transplanter used in Example 1, the seedlings were raised from the pot, and the roots were pulled out of the pot and transplanted to the field. Could not be carried out smoothly, so that subsequent cultivation was not carried out.

Comparative Example 4 (1) 95 parts by mass of the above-mentioned cultivation base material and 5 parts by mass of the heat-fusible fiber were put into a mixer container, and stirred to prepare cultivation soil for seedling raising. At that time, a fiber mass having a diameter of 10 to 20 mm was generated in the seedling raising soil. (2) Using a part of the seedling cultivation soil obtained in the above (1), the bending strength and the amount of deflection of the sheet-like material after the heat treatment and the compressive stress of the molded product were measured by the method described above. As shown in Table 2. (3) The remaining part of the seedling cultivation soil obtained in the above (1) was potted with a pot seedling box (“Pot 44 manufactured by Minoru Sangyo Co., Ltd.) using an automatic pot sowing machine in the same manner as in (3) of Example 1.
No. 8 seedling box ") was automatically filled with soil, but the filling was practically difficult due to the presence of a large fiber mass, so no further evaluation was performed.

[0045]

[Table 1]

[0046]

[Table 2]

From the results in Tables 1 and 2, the fiber length is in the range of 0.5 to 2 mm and the aspect ratio is in the range of 20 to 30.
In the range of 0, the cultivation soil for seedling raising of Examples 1 to 4 comprising a heat-fusible fiber having a fiber moisture content of 10% or less based on the fiber mass and a crimp number of 6 / cm or less, In order to prevent the formation of fiber clumps when mixed with the cultivation base material, the cultivation medium for raising seedlings containing the heat-fusible fibers is filled into a small container for cultivating plants having a volume of 10 cm ³ or less with good operability. What you can do,
Moreover, a heat treatment is performed and the heat-fusible fiber is melt-bonded to form a root pot excellent in strong high handleability,
That transplanting can be performed smoothly,
And it turns out that a seedling can be grown well. On the other hand, the seedling cultivation soil of Comparative Example 1 containing no heat-fusible fiber, the seedling cultivation soil of Comparative Example 2 containing a heat-fusible fiber having a fiber length of less than 0.5 mm (0.3 mm), and Fiber length is 5mm
The seedling cultivation soil of Comparative Example 3 in which a heat-fusible fiber having a moisture content of 15% was blended, the bending strength, deflection amount, and compressive stress of the heat-treated seedling cultivation soil were all equal to those of Examples 1 to 3.
No higher than the cultivation for seedling raising of No. 4 and a strong root mortar was not formed after the heat treatment, and it could not be planted by a transplanter, indicating that the handleability was poor. In addition, the seedling cultivation medium of Comparative Example 4 in which a heat-fusible fiber having a fiber length of 5 mm and a number of crimps of 7.9 / cm was mixed, a fiber mass was generated when compounded with the cultivation base material. It is difficult to fill a container for growing plants, particularly a small container for growing plants having a volume of 10 cm ³ or less, using an automatic pot sowing machine.

[0048]

According to the seedling cultivation soil of the present invention, the heat-fusible fiber blended in the seedling cultivation soil is melt-bonded by heat treatment, thereby bonding the fibers to each other, and combining the fibers with the components in the soil cultivation base material. Since a three-dimensional net-like reinforcement structure is formed in the seedling cultivation soil by being bonded, a high-strength root mortar can be formed. As a result, when cultivating seedlings together with root pots using a transplanter or the like, the seedling cultivation soil of the present invention can perform the planting operation smoothly without causing root collapsing. In addition, the seedling cultivation soil of the present invention can grow plant seedlings healthy without causing growth inhibition or the like. In particular, in the seedling cultivation soil of the present invention, when preparing the seedling cultivation soil by blending the heat-fusible fiber with the cultivation base material, no fiber clumps are generated,
Since the heat-fusible fibers are evenly dispersed in the seedling cultivation soil, when filling small plant growing containers with a volume of 10 cm ³ or less using an automatic filling device or the like, poor filling or inability to fill. And a small pot for growing plants can be smoothly filled with good workability, and a strong pot in the small pot for growing plants can be formed. .

[Brief description of the drawings]

FIG. 1 is a view showing a method for measuring the bending strength and the amount of deflection of a soil for raising seedlings of the present invention.

[Explanation of symbols]

 a Sheet-shaped seedling cultivation soil (heat-treated) 1a Support 1b Support 2a Sheet-shaped seedling cultivation end fixing means 2b Sheet-shaped seedling cultivation end fixing means 3 Pressing plate 4 Weight detection unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nagi Hisashi 1-2-1, Kaigandori, Okayama-shi, Okayama Prefecture Inside Kuraray Co., Ltd. (72) Inventor Shigeharu Motooka 447, Shimoichi, Sanyo-cho, Akagun-gun, Okayama Minoru Sangyo Co., Ltd. (72) Inventor Kazunori Fujii 447 Shimoichi, Sanyo-cho, Akaiwa-gun, Okayama Prefecture F-term (reference) 2B022 AA05 AB11 AB15 AB17 BA02 BA04 BA16 BA23 BB01 BB02 BB10 2B027 NA10 NC05 NC14 NC24 NC27 NC36 NC40 NC41 ND03

Claims (9)

[Claims] Claims: 1. A cultivation material having a fiber length of 0.5 to 2 mm,
A cultivation soil for raising seedlings, comprising a heat-fusible fiber having an aspect ratio of 20 to 300, a fiber moisture content of 10% or less based on the mass of the fiber, and a crimp number of 6 / cm or less. 2. The seedling cultivation soil according to claim 1, which is a seedling cultivation soil for use in a container for cultivating a plant having a volume of 10 cm ³ or less. 3. The heat-fusible fiber comprises: a fiber-forming polymer;
3. A heat-fusible composite spun fiber and / or mixed spun fiber comprising a thermoplastic polymer having a melting point or softening point lower by at least 20 [deg.] C. than the fiber-forming polymer.
The soil for raising seedlings described in the above. 4. The cultivation soil for raising seedlings according to claim 1, wherein the cultivation base material is a cultivation base material mainly composed of peat moss and / or pearlite together with soil. 5. The compounding ratio of the cultivation base material and the heat-fusible fiber is as follows:
The culture soil for raising seedlings according to any one of claims 1 to 4, wherein the mass ratio is 99: 1 to 85:15. 6. The seedling cultivation soil according to claim 1, wherein the heat-fusible fibers are melt-bonded in the seedling cultivation soil. 7. A claim that satisfies at least one of a requirement that a bending strength determined by the following equation (I) is 30 mN or more and a requirement that a deflection amount determined by the following equation (II) is 5 or more. Item 7. The seedling cultivation soil according to Item 6. ## EQU1 ## Flexural strength (mN) = {(50.times.B) / (25.times.A)}. Times.3 / 2 (I) Deflection amount = C / A (II) 500g /
m ² sheet-shaped material, and then heat-treated to melt and bond the heat-fusible fibers in the seedling culture soil to obtain a sheet-shaped material having a length of 100 mm and a width of 25 mm. Indicates the thickness (mm) of the test piece when a pressure of 53.9 kPa is applied to the entire upper surface of the test piece, and B indicates that the both ends of the test piece are placed on the left and right support bases separated by a distance of 50 mm. Is fixed, and the area of 2 cm ²
Is placed at a speed of 10 mm / min and lowered, and the load (maximum load) (mN) applied to the test piece when the test piece is damaged is shown. Indicates the deflection depth (mm). ] 8. The heat-fusible fiber in the seedling cultivation is melt-bonded by heat-treating the seedling cultivation soil to a density of 0.10%.
g / cm ³ was used as a test piece, and a circular pressure plate having an area of 2 cm ² was placed on the center of the test piece and lowered at a speed of 10 mm / min. The cultivated soil for raising seedlings according to claim 6 or 7, wherein a compressive stress when descending is 10 kN or more. 9. The seedling raising medium according to claim 1, wherein the seedling raising medium is filled in a plant growing container, irrigated, and then heat-treated to melt-bond the heat-fusible fibers in the medium. How to solidify the soil.