JP2015195779A - Artificial soil particles and artificial soil culture medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensive artificial soil particles which can hold moisture required for growth of a plant while maintaining strength, and which is easy to handle when planting.SOLUTION: An artificial soil particle 50 comprises a base 10 including an inorganic porous body 1, and a coating layer 20 including a fiber 2 which coats at least one part of a surface of the base 10. The inorganic porous body 1 is perlite, and the fiber 2 is a hydrophilic fiber with a fiber length of 0.3-1 mm. The ratio (a/b) of the average thickness (a) of the coating layer 20 and the mean diameter (b) of the base 10 is 1/20-1/2.

Description

  The present invention relates to artificial soil particles and an artificial soil medium using the artificial soil particles.

  In recent years, there have been an increase in indoor planting for planting living spaces and plant factories for growing plants such as vegetables indoors. In such indoor greening and plant factories, there is a movement to use artificial soil with advanced functions instead of natural soil. For example, an inexpensive inorganic porous material may be used as the artificial soil. However, since the inorganic porous body generally does not have sufficient strength, the porous structure of the inorganic porous body is destroyed during transportation and planting work, and the function as soil such as water retention is reduced, fine powder etc. May occur and workability may be reduced. In addition, since the inorganic porous body has a large friction between particles due to the unevenness of the surface, it is difficult to plant a plant and the workability may be lowered.

  In order to solve the above problems, for example, in the artificial soil described in Patent Document 1, the surface of the granular foamed material is covered with a greening material such as pearlite, and the water retention is improved while maintaining the soil form. It is said.

  Further, as in Patent Document 2, a soil substitute is also known in which zeolite and polyester short fibers are attached to the surface of foam particles made of synthetic resin and granulated.

JP 2009-11190 A Japanese Patent Laid-Open No. 7-50923

  However, in the artificial soil of Patent Document 1, since pearlite is present on the surface side of the foamed material, it is not possible to completely suppress the destruction of the structure of pearlite caused by transportation, planting work, irrigation, etc. As a result, it is difficult to maintain the function as artificial soil such as water retention. In addition, inorganic porous bodies such as pearlite can retain moisture due to the porous structure, but the water absorption rate is slow, so if the inorganic porous body is exposed to the outside, water can be absorbed by irrigation or the like. Even if it supplies, it will be washed away early and there is a possibility that water required for the growth of the plant cannot be sufficiently retained.

  On the other hand, since the soil substitute of patent document 2 uses the synthetic resin foam as a base material, it is thought that a certain amount of intensity | strength is maintained. However, since the foam made of synthetic resin is inferior in water retention compared with the inorganic porous body, for example, when cultivating root vegetables and the like, it cannot function sufficiently as artificial soil. Moreover, since the synthetic resin foam and the polyester short fiber adhered to the surface thereof are expensive materials compared to the inorganic porous body, it is considered difficult to disseminate them as artificial soil to be used in large quantities. .

  The present invention has been made in view of the above problems, and can maintain moisture and retain moisture necessary for plant growth, and is easy to handle at the time of operations such as planting. The purpose is to provide artificial soil particles. Another object of the present invention is to provide a high-performance and inexpensive artificial soil medium using the artificial soil particles.

The characteristic configuration of the artificial soil particles according to the present invention for solving the above problems is as follows:
A base including an inorganic porous body;
A coating layer comprising fibers covering at least a part of the surface of the base;
It is in having.

  According to the artificial soil particle of this structure, the intensity | strength of the artificial soil particle is improved by coat | covering at least one part of the surface of the base containing an inorganic porous body with a fiber. For this reason, for example, even when an external pressure is applied during operations such as planting, the structure of the artificial soil particles is difficult to be destroyed, and a stable function as an artificial soil medium can be exhibited. Further, since the fibers of the covering layer have a smaller friction than the inorganic porous body, the artificial soil particles have appropriate fluidity, enabling smooth planting and improving workability. Furthermore, since the fibers of the coating layer can quickly adsorb moisture during irrigation and retain water in the gaps between the fibers, it is possible to suppress early loss of moisture immediately after irrigation. As a result, moisture can be efficiently absorbed and retained in the pores of the inorganic porous material contained in the base, and the water retention of the artificial soil particles can be improved. Further, since the fiber is used only for coating the surface of the base, the amount of the relatively expensive fiber used can be reduced, which can contribute to the cost reduction of the artificial soil particles.

In the artificial soil particles according to the present invention,
The inorganic porous body is preferably pearlite.

  According to the artificial soil particle of this structure, since the pearlite which has a high porosity and the pore of an appropriate size is used for a base as an inorganic porous body, the water retention power of a base can fully be ensured. . As a result, the water retention of artificial soil particles can be further improved. In addition, pearlite has a particularly high porosity among inorganic porous bodies and has a very small solid content, and therefore, the amount of waste at the time of disposal can be reduced. Furthermore, since pearlite is inexpensive, it is suitable for artificial soil used in large quantities and is economically advantageous.

In the artificial soil particles according to the present invention,
The fiber preferably has a fiber length of 0.3 to 1 mm.

  According to the artificial soil particle of this structure, since the fiber has an appropriate fiber length, the moisture adsorption force of the artificial soil particle can be improved while effectively reinforcing the base. As a result, inexpensive artificial soil particles having an excellent balance between strength and water retention can be provided.

In the artificial soil particles according to the present invention,
The fiber is preferably a hydrophilic fiber.

  According to the artificial soil particle of this structure, the water | moisture-content adsorption | suction power of artificial soil particle can be improved reliably, using a hydrophilic fiber as a fiber which coat | covers a base part, reinforcing a base part reliably. As a result, inexpensive artificial soil particles having an excellent balance between strength and water retention can be provided.

In the artificial soil particles according to the present invention,
The ratio (a / b) between the average thickness (a) of the coating layer and the average diameter (b) of the base is preferably 1/20 to 1/2.

  According to the artificial soil particles of this configuration, since the ratio of the average thickness of the coating layer and the average diameter of the base is set in an appropriate range, the water retention force resulting from the base and the strength resulting from the coating layer, An appropriate balance between fluidity and moisture adsorption and material costs is maintained. As a result, it is possible to provide inexpensive artificial soil particles having an excellent balance of strength, fluidity, and water retention.

In the artificial soil particles according to the present invention,
The inorganic porous body preferably has a porosity of 80% or more.

  According to the artificial soil particles of this configuration, since the inorganic porous body has a porosity of 80% or more, it is possible to sufficiently ensure the amount of water that can be retained in the inorganic porous body, so-called water retention capacity. As a result, the water retention of artificial soil particles can be further improved.

In the artificial soil particles according to the present invention,
It preferably has a particle size of 2 to 10 mm.

  According to the artificial soil particles of this configuration, since the particle size of the granular material is adjusted to an appropriate range, the balance between strength and water retention is maintained, and easy-to-handle artificial soil suitable for root vegetable cultivation. A medium can be provided.

The characteristic configuration of the artificial soil culture medium according to the present invention for solving the above problems is
The use of any one of the above artificial soil particles.

  According to the artificial soil culture medium of this configuration, since artificial soil particles in which at least a part of the surface of the base including the inorganic porous body is covered with fibers are used, for example, externally at the time of work such as planting Even when a certain pressure is applied, the structure of the artificial soil particles becomes difficult to be destroyed, and the stable function as the artificial soil medium can be exhibited. In addition, since the fibers of the artificial soil particle coating layer have less friction than the inorganic porous material, the artificial soil particles have adequate fluidity, enabling smooth planting and improving workability. To do. Furthermore, since the fibers of the coating layer can quickly adsorb moisture during irrigation and retain water in the gaps between the fibers, it is possible to suppress early loss of moisture immediately after irrigation. As a result, moisture can be efficiently absorbed and retained in the pores of the inorganic porous body contained in the base of the artificial soil particles, and the water retention of the artificial soil medium can be improved. Moreover, since the fiber used for the artificial soil particles is used only to coat the surface of the base, the amount of the relatively expensive fiber used can be reduced, which can contribute to the cost reduction of the artificial soil medium.

FIG. 1 is an explanatory view schematically showing artificial soil particles according to the present invention. FIG. 2 is an explanatory view schematically showing an artificial soil culture medium using artificial soil particles according to the present invention. FIG. 3 is a graph showing the water retention amount of artificial soil particles according to the present invention.

  Hereinafter, the embodiment regarding the artificial soil particle which concerns on this invention, and the artificial soil culture medium using the said artificial soil particle is described based on FIGS. 1-3. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below.

<Artificial soil particles>
FIG. 1 is an explanatory view schematically showing artificial soil particles 50 according to the present invention. FIG. 1A shows an artificial soil particle 50 using the inorganic porous body 1 that is a granular material as a base 10 as it is, and FIG. 1B shows a base by assembling a plurality of minute inorganic porous bodies 1. 10 is an artificial soil particle 50 having formed 10. FIG. 2 is an explanatory view schematically showing an artificial soil culture medium 100 using the artificial soil particles 50 according to the present invention of FIG. The artificial soil particle 50 includes a base 10 including the inorganic porous body 1 and a coating layer 20 that covers at least a part of the surface of the base 10 with the fibers 2. The inorganic porous body 1 has a large number of pores 3 from the surface to the inside, and can retain moisture in the pores 3. The coating layer 20 reinforces the inorganic porous body 1 constituting the base 10 by covering a part or the whole of the surface of the base 10 with the fibers 2 and maintains the strength as the artificial soil particles 50. The base 10 is formed by granulating a plurality of minute inorganic porous bodies 1 with a binder or the like as shown in FIG. 1B, even if the inorganic porous body 1 is granular as shown in FIG. It may be a granulated product. When the base 10 is formed as a granulated product shown in FIG. 1B, voids 4 are formed between the inorganic porous bodies 1, and moisture can also be retained in the voids 4. Therefore, the state of the void 4 (for example, the size, number, shape, etc. of the void 4) relates to the amount of water that can be held by the artificial soil particles 50, so-called water retention capacity. The state of the void 4 can be adjusted by changing the amount, type, size, and the like of the inorganic porous body 1 when the base 10 is granulated.

  Since the inorganic porous body 1 has a high porosity, it has a large water holding capacity. For example, when pearlite is employed as the inorganic porous body 1, the porosity, that is, the proportion of the space per unit volume is 80 to 90%, and moisture can be retained in the space. Therefore, the inorganic porous body 1 such as pearlite can be used as an excellent water retention material. However, pearlite, etc., crushed and fired volcanic rocks and then foamed them to increase the porosity, so the structure is very fragile, and the porous structure of the inorganic porous material is destroyed during transportation and planting operations. In addition, functions as soil such as water retention may be reduced. Among the inorganic porous bodies 1, in particular, the pearlite pearlite and the like have irregular surface irregularities, so that the friction between the particles becomes particularly large, and plant roots can be directly planted in the soil of the inorganic porous body 1. Difficult, it was necessary to cover the soil such as pearlite perlite after roots. Therefore, in the artificial soil particles 50 of the present invention, the coating layer 20 is provided on the surface of the inorganic porous body 1 to improve the strength of the artificial soil particles 50 and reduce the friction between the artificial soil particles 50 to reduce the artificial soil particles. 50 fluidity is improved. As a result, the plant can be planted smoothly while maintaining the function as soil such as water retention. The fiber 2 is fixed to the surface of the base 10 with a binder or the like, and functions as a reinforcing material that reinforces the surface of the base 10 and a friction reducing material that reduces friction between the artificial soil particles 50. The coating layer 20 can be formed, for example, by adding the fiber 2 and the binder to the base 10 and granulating. In addition, although the shape of the artificial soil particle 50 of this embodiment is comprised in the solid shape close | similar to a spherical shape as shown in FIG. 1, for example, a flat rugby ball shape, a confetti shape having protrusions, a polyhedral shape, It is also possible to configure a plate shape, an indefinite shape or the like having a certain thickness or more. Moreover, the artificial soil particle 50 which is colorful and excellent in aesthetics can be produced by dye | staining the fiber 2 previously with a pigment | dye, dye, etc.

  As shown in FIG. 2, the artificial soil culture medium 100 forms a fixed gap 30 between the artificial soil particles 50 in a state of aggregate structure in which a plurality of artificial soil particles 50 are aggregated. Since air and water can pass through the gap 30, excess water can be discharged while holding water necessary for the plant P. The inorganic porous body 1 such as pearlite used for the base 10 of the artificial soil particle 50 has a high water retention capacity because of its high porosity, but the size of the pores 3 is relatively small, and the pores 3 enter the pores 3. Water absorption rate is slow. For this reason, even if water is supplied by irrigation or the like, the water may not be sufficiently absorbed into the inorganic porous body 1 and may be washed away from the gaps 30 and the plant may not be able to use the water effectively. Therefore, it is preferable to use hydrophilic fibers as the fibers 2 used in the coating layer 20 that covers the base 10. When hydrophilic fibers are used for the covering layer 20, as shown in FIG. 2, moisture W is adsorbed to the fibers 2 of the covering layer 20, and the moisture W is also retained in the gaps 30 formed between the plurality of artificial soil particles 50. Is done. That is, the fiber 2 functions as an adsorbent for water. Thereby, the early runoff of the water | moisture content W from the artificial soil culture medium 100 can be suppressed. Moisture W adsorbed on the fibers 2 of the coating layer 20 is gradually absorbed by the pores 3 of the inorganic porous body 1 and is held in the base 10 of the artificial soil particles 50. When the artificial soil particle 50 constituting the artificial soil medium 100 is the granulated product of FIG. 1B, the water W is absorbed into the voids 4 formed between the inorganic porous bodies 1 by capillary action, and further inorganic. It is absorbed by the pores 3 of the porous body 1. In addition, even when the moisture W is excessively present in the gap 30, the moisture W is absorbed by the base 10 of the artificial soil particles 50, so that the air permeability of the artificial soil culture medium 100 can be ensured more than a certain level. There is little risk of root rot of cultivated plants. When the moisture W present in the gap 30 of the artificial soil culture medium 100 decreases, the moisture W held in the base 10 is gradually released and supplied to the plant. If such a phenomenon is utilized, it becomes possible to reduce watering to a plant.

  The porosity of the inorganic porous body 1 is related to the water retention capacity of the base 10. If the porosity of the inorganic porous body 1 used for the base 10 is low, the water retention capacity of the base 10 is lowered, and the water retention as the artificial soil particles 50 may not be sufficiently maintained. Therefore, the inorganic porous body 1 used for the base 10 preferably has a porosity of 80% or more, and more preferably has a porosity of 85 to 95%. If the porosity of the inorganic porous body 1 is less than 80%, the water retention as the artificial soil particles 50 may not be sufficiently maintained.

The inorganic porous body 1 used for the base 10 includes a porous mineral, an inorganic foam, and an inorganic porous aggregate. Examples of the porous mineral include pearlite, diatomaceous earth, vermiculite, and pumice. Examples of the inorganic foam include glass foam, shale foam, and shirasu balloon. Examples of the inorganic porous aggregate include foam concrete. And foam bricks, and among them, perlite is preferable. The above-described inorganic porous body 1 can be used in a state where two or more kinds are mixed. Among these inorganic porous bodies 1, pearlite has a particularly high porosity, so that the water retention capacity of the base 10 can be sufficiently secured. In addition, pearlite has excellent functions such as fertilization, activation of microorganisms, promotion of root elongation, prevention of fertilizer burning, etc. is there. Therefore, perlite can be suitably used as the base 10 of the artificial soil particle 50 used in a plant factory or indoors. Furthermore, since pearlite is inexpensive, it is suitable for artificial soil used in large quantities and is economically advantageous. Since the inorganic porous body 1 contains a lot of mineral components, if the inorganic porous body 1 is used as the base 10 of the artificial soil particles 50, the plant can be grown without adding a mineral component separately at the time of plant cultivation. Can do. For example, the composition of perlite pearlite is SiO ₂ : 75%, Al ₂ O ₃ : 14%, Fe ₂ O ₃ : 0.9%, CaO: 0.1%, K ₂ O: 4.2%, Na ₂ O: 3.5%, which contains a lot of plant essential elements such as potassium, calcium, and iron. When pearlite is used for the base 10 of the artificial soil particle 50 of the present invention, it is possible to compensate for the disadvantages of pearlite, strength, fluidity, and water absorption speed while maintaining the excellent function of pearlite, and excellent artificial Soil particles can be obtained.

  Synthetic fibers or natural fibers are appropriately selected for the fibers 2 constituting the coating layer 20. Examples of synthetic fibers include vinylon, polyester, nylon, acrylic, acetate, urethane, and polyolefin. Examples of natural fibers include wool, cotton, rayon, and cellulose. Among these fibers, preferable hydrophilic fibers include, for example, vinylon, urethane, nylon, acetate, cotton, wool, rayon, and cellulose, and among these, vinylon is more preferable.

  As described above, the fiber 2 of the covering layer 20 functions as a reinforcing material for the artificial soil particles 50, functions as a friction reducing material that reduces friction between the artificial soil particles 50, and functions as an adsorbent for moisture. It has. Here, the strength and water retention of the artificial soil particles 50 can be adjusted by changing the fiber length and fiber diameter of the fibers 2 covering the base 10. The fiber length of the fiber 2 is preferably 0.3 to 1 mm, more preferably 0.4 to 0.6 mm. When the fiber length of the fiber 2 is shorter than 0.3 mm, the moisture adsorption force of the fiber 2 of the coating layer 20 is lowered, and there is a possibility that the moisture W cannot be sufficiently retained in the gap 30 of the artificial soil culture medium 100. Moreover, it becomes difficult to fix the fibers 2 and the strength of the artificial soil particles 50 may not be sufficiently improved. On the other hand, when the fiber length of the fiber 2 is longer than 1 mm, the fiber 2 is not sufficiently fixed to the surface of the base portion 10 of the artificial soil particle 50 and becomes fuzzy, and the strength of the artificial soil particle 50 cannot be sufficiently improved. There is a fear. The fiber diameter of the fiber 2 is preferably 15 μm or more. When the fiber diameter of the fiber 2 is smaller than 15 μm, the gap formed between the fibers 2 is reduced by shrinkage due to the surface tension of water when the artificial soil particles 50 are dried, and the moisture W is sufficiently retained in the gap between the fibers 2. It becomes impossible to control the early outflow of the water W immediately after irrigation.

  In order to improve the strength, fluidity, and water retention of the artificial soil particles 50, the average thickness a of the coating layer 20 and the average diameter b of the base 10 are set to appropriate sizes, and the water retention due to the base 10 is It is necessary to consider the balance between the strength, fluidity, and moisture adsorption force due to the fibers 2 of the coating layer 20. In this embodiment, the average thickness a of the coating layer 20 is set to 500 to 3000 μm, preferably 1000 to 2000 μm. If the average thickness a of the coating layer 20 is set to be smaller than 500 μm, the moisture W existing outside the artificial soil particles 50 cannot be sufficiently adsorbed and retained, and the early loss of the moisture W from the gap 30 can be suppressed. May become difficult. Moreover, since the covering layer 20 provides the artificial soil particles 50 with rigidity and fluidity, if the average thickness a is set to be smaller than 500 μm, there is a possibility that sufficient strength and fluidity of the artificial soil particles 50 may not be obtained. is there. On the other hand, if the average thickness a of the coating layer 20 is set to be greater than 3000 μm, the water permeability of the base portion 10 is deteriorated and the amount of water that can be retained may be reduced. Moreover, since many comparatively expensive fibers 2 are used, it becomes economically disadvantageous. The average diameter b of the base 10 is set to 1.5 to 9 mm, preferably 3 to 6 mm. If the average diameter b of the base 10 is set to be smaller than 1.5 mm, it becomes difficult to store sufficient moisture in the base 10. On the other hand, if the average diameter b of the base 10 is set to be larger than 9 mm, the gap 30 between the artificial soil particles 50 becomes too large, the drainage of the artificial soil medium 100 becomes excessive, and the plant becomes difficult to absorb water and die. There is a fear. In addition, in the relationship between the average thickness a of the coating layer 20 and the average diameter b of the base portion 10, it is also important to set the ratio a / b in an appropriate range. In this embodiment, the ratio a / b is , 1/20 to 1/2, preferably 1/10 to 1/5. If the ratio a / b is set to be smaller than 1/20, the thickness of the coating layer 2 becomes too thin with respect to the base portion 10, and the water W existing outside cannot be sufficiently adsorbed. There is a risk that the performance will be reduced. Moreover, there exists a possibility that the intensity | strength and fluidity | liquidity as the artificial soil particle 50 cannot be maintained. On the other hand, when the ratio a / b is set to be larger than 1/2, the base 10 becomes relatively small with respect to the coating layer 2, and there is a possibility that the artificial soil particles 50 cannot sufficiently retain the moisture W.

  The particle size of the artificial soil particles 50 is set to 2 to 10 mm. If the particle size of the artificial soil particles 50 is set to be smaller than 2 mm, the gap 30 formed between the artificial soil particles 50 becomes too small, the air permeability of the artificial soil medium 100 is lowered, and root rot of the cultivated plant may occur. There is. Moreover, it becomes difficult to form the coating layer 20 on the base 10. On the other hand, if the particle size of the artificial soil particles 50 is set to be larger than 10 mm, the gaps 30 formed between the artificial soil particles 50 become too large, the drainage of the artificial soil medium 100 becomes excessive, and the plant hardly absorbs moisture. There is a risk of becoming dead. Moreover, there is a possibility that the supporting ability of the plant also decreases.

<Method for producing artificial soil particles>
The manufacturing method of the artificial soil particle 50 of this invention is demonstrated. When the granular material of the inorganic porous body 1 is used for the base 10, the granular material having a desired particle diameter is selected through a sieve or the like and used as it is as the base 10. When the base 10 of the artificial soil particle 50 is formed by assembling a plurality of minute inorganic porous bodies 1, the inorganic porous body 1 is mixed by adding a binder or a solvent, and the mixture is introduced into the granulator. And forming a granulated product by a known granulation method such as rolling granulation, fluidized bed granulation, stirring granulation, compression granulation, extrusion granulation, crush granulation, melt granulation, spray granulation or the like. Can do. The obtained granulated product is dried and classified as necessary and used as the base 10. In addition, a binder is added to the inorganic porous body 1, and further a solvent or the like is added and kneaded as necessary, and this is dried and made into a block shape, and pulverizing means such as a mortar and pestle, a hammer mill, a roll crusher, etc. It is also possible to obtain a granulated product by pulverizing as appropriate. The granulated product can be used as the base 10 as it is, but it is preferable to adjust to a desired particle size by sieving.

  Examples of the binder include polyolefin-based binders, polyvinyl alcohol-based binders, polyurethane-based binders, vinyl acetate-based binders such as vinyl acetate and ethylene vinyl acetate, urethane resin-based binders such as urethane resins and vinyl-urethane resins, acrylic resin-based binders, Examples include synthetic resin binders such as silicone resin binders; polysaccharides such as starch, carrageenan, xanthan gum, gellan gum, and alginates, and natural product binders such as proteins such as polyamino acids and glues.

  In forming the covering layer 20, the surface of the obtained base 10 is covered with the fibers 2 to form the covering layer 20. For example, the fiber 2 and the binder are added to the base 10 and mixed, and the fiber 2 is attached to the surface of the base 10. At this time, it is preferable to use a water-insoluble binder. Thereby, since it can prevent that the coating layer 20 collapses by irrigation etc., the intensity | strength and durability of the artificial soil particle 50 can be maintained. Examples of the water-insoluble binder include binders mainly composed of polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, and urethane resins such as polyurethane and vinyl urethane. Of these, a water-insoluble binder mainly composed of polyethylene is preferred.

  The Example regarding the artificial soil particle of this invention is described. In the examples, the water retention amount (sprinkling water retention amount) at the time of watering the artificial soil medium was measured, and the water retention capacity of the artificial soil medium due to the difference in the structure of the artificial soil particles was evaluated.

[Production of artificial soil particles]
Perlite (manufactured by Taiheiyo Material Co., Ltd.) is used as the inorganic porous material constituting the base of the artificial soil particles, and vinylon short fibers (length 0.5 mm, Kuraray Co., Ltd.) are used as the fibers constituting the coating layer of the artificial soil particles. Made). The pearlite was sieved and adjusted so that the average particle size of the base was 2 to 4 mm. Next, while stirring pearlite with a stirring and mixing granulator (manufactured by G-Labo Co., Ltd.), a polyethylene emulsion (Sepoljon (registered trademark) G315, manufactured by Sumitomo Seika Co., Ltd., concentration 40% by weight) is applied by spraying. A vinylon short fiber was added to uniformly adhere the vinylon short fiber to the surface of the pearlite. The spraying of the polyethylene emulsion and the introduction of the vinylon short fibers were repeatedly performed until the particle size of the artificial soil particles became a desired size. The amounts of polyethylene emulsion and vinylon short fibers used were adjusted to 10 wt% and 20 wt%, respectively, based on the weight of pearlite. The pearlite with vinylon short fibers attached is dried at 60 ° C, then heated to 100 ° C, the polyethylene resin in the polyethylene emulsion is melted, and the vinylon short fibers are fused and fixed. Artificial soil particles covered with the whole were prepared. Artificial soil particles were sieved and adjusted so that the particle size was in the range of 3 to 5 mm. For the artificial soil particles of Comparative Example 1, the base of pearlite was not covered with fibers, and the particles with the exposed pearlite surface were used as artificial soil particles as they were. As the artificial soil particles of Comparative Example 2, a commercially available hydrocorn (manufactured by Miura Gardening Co., Ltd.) was used as it was.

<Watering capacity>
Fill the chromatographic tube with 140 cc of each artificial soil particle to be tested and inject 110 ml of water (10 ml x 6 times + 20 ml x 3 times) from the top of the chromatographic tube at intervals of 3 to 5 minutes. The water retention amount when the interval of falling water from the water was 3 minutes or more was measured, and converted to the water retention amount for 100 cc of the soil to be tested as the water spray retention amount (volume%). The amount of water retention was calculated by subtracting the weight of the soil to be tested that had been measured in advance from the weight of the soil subjected to the above test.

<Test results>
FIG. 3 is a graph showing the water retention amount of artificial soil particles according to the present invention. As shown in FIG. 3, the water retention amount of the artificial soil particles of the example was 35% by volume. On the other hand, in the artificial soil particles of Comparative Example 1, the water spray retention amount was 25% by volume, which was about 70% of the performance of the artificial soil particles of Examples. This is probably because the water absorption rate of pearlite was slow, so that water could not be absorbed sufficiently and was discharged out of the system. In the artificial soil particles of Comparative Example 2, the water retention amount was 10% by volume, which was only less than 30% of the performance of the artificial soil particles of the Examples. Thus, the artificial soil particles of the present invention have a high water sprinkling capacity compared to conventional artificial soil particles, and it was shown that high water retention can be realized while using inexpensive materials. .

  The artificial soil particles according to the present invention and the artificial soil medium using the artificial soil particles can be used in agriculture and horticulture in home gardens, plant factories, indoor greening, and the like.

DESCRIPTION OF SYMBOLS 1 Inorganic porous body 2 Fiber 4 Cavity 10 Base part 20 Coating layer 50 Artificial soil particle 100 Artificial soil medium a Average thickness of coating layer b Average diameter of base part

Claims (8)

A base including an inorganic porous body;
A coating layer comprising fibers covering at least a part of the surface of the base;
Artificial soil particles with.   The artificial soil particle according to claim 1, wherein the inorganic porous body is pearlite.   The artificial soil particles according to claim 1 or 2, wherein the fibers have a fiber length of 0.3 to 1 mm.   The artificial soil particle according to any one of claims 1 to 3, wherein the fiber is a hydrophilic fiber.   The ratio (a / b) between the average thickness (a) of the coating layer and the average diameter (b) of the base is 1/20 to 1/2. Artificial soil particles.   The artificial soil particles according to any one of claims 1 to 5, wherein the inorganic porous body has a porosity of 80% or more.   The artificial soil particle according to any one of claims 1 to 6, which has a particle size of 2 to 10 mm.   The artificial soil culture medium using the artificial soil particle as described in any one of Claims 1-7.

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