JP5634446B2 - Granular plant breeding body - Google Patents

Description

  The present invention contains a cation exchange filler and an anion exchange filler in a granular gel formed from alginate and polyvalent metal ions, and has excellent fertilizer retention, excellent water retention and excellent The present invention relates to a granular plant breeding body having air permeability.

  In recent years, various artificial soils have been commercialized due to soaring vegetable prices and the boom in kitchen gardens, but most of them use natural materials, and there are large variations in quality, especially with natural organic materials such as peat moss. However, it is becoming difficult to obtain high quality materials due to resource depletion and environmental destruction problems.

  As described above, one of the artificial soil materials that can replace natural soil is lightweight because of its porous cell shape, and has excellent air permeability and water retention, as well as large cation exchange capacity and excellent fertilizer retention. In addition, peat moss has been used favorably because it is inexpensive. However, although peat moss is excellent in water retention due to the porous cellular shape as described above, once it is completely dried, water repellency becomes stronger, and there is a problem that it becomes difficult to retain water even if moisture is added again, If a large amount of water is supplied to prevent drying, the water is retained excessively, resulting in poor air permeability, causing root rot and disease.

  In order to solve such problems, many natural soil substitutes such as alginic acid gel and porous inorganic material have been proposed (Patent Documents 1 to 3).

  Patent Document 1 discloses an aseptic plant artificial soil used for growing plant seeds or redifferentiated tissues in an aseptic environment, which is formed into a granular or string-like molded body using a gel support material, and the molded body. Disclosed is an artificial soil for aseptic plants characterized by the assembly of A granular gel is formed using alginate or the like as a gel support material, and water retention and air permeability are simultaneously ensured. However, in the artificial soil of Patent Document 1, alginate is only ion-crosslinked to form a granular gel, and sufficient fertilizer retention cannot be obtained.

  In Patent Document 2, the cation exchange capacity is 50 (cmol / kg) or more and 400 (cmol / kg) or less, and the median diameter of the pore distribution is 0.01 (μm) or more and 15.00 (μm) or less. There is disclosed an inorganic porous body characterized in that zeolite is formed on the outer periphery. However, since the pore size of the inorganic porous material is as small as 15 μm or less, the plant is difficult to absorb water, and there is a cation exchange capacity, but no anion exchange material is used and the anion exchange capacity is considered to be low. It is done. In addition, it is waste sand (casting sand) that is discharged as dust waste from the dust collector of the foundry as a raw material, and must be fired at a high temperature (800 ° C) during production. However, there are problems such as inclusion.

  Patent Document 3 discloses a bead-type alginic acid gel water treatment agent produced by dropping a 0.1 to 10% by weight alginate solution into a polyvalent cation solution to crosslink alginic acid. ing. However, since no ion adsorbent is contained, there is a problem that the adsorption ability of cations and anions is low.

Japanese Patent Laid-Open No. 6-20962 Japanese Patent Laid-Open No. 2002-80284 Japanese Patent Laid-Open No. 11-70384

  The present invention solves the problems of conventional natural soil substitutes as described above, has excellent fertilizer retention with both high cation exchange capacity and anion exchange capacity, and is easily absorbed by plants. An object of the present invention is to provide a granular plant breeding body having excellent water retention with respect to water and excellent breathability that returns to a highly breathable state in a short time even when kept in a saturated state.

  As a result of intensive studies to solve the above-mentioned object, the present inventors have obtained a granular plant growth body composed of an alginate gel containing a cation exchange filler and an anion exchange filler. In addition, the present inventors have found that by defining the anion exchange capacity within a specific range, it is possible to provide a granular plant growing body having excellent fertilizer retention, excellent water retention and excellent breathability, and to complete the present invention. It came.

  The present invention relates to a granular plant growth body comprising an alginate gel having a particle size of 0.2 to 6 mm, a cation exchange capacity of 5 meq / 100 mL or more and an anion exchange capacity of 5 meq / 100 mL or more.

In order to suitably implement the present invention,
the amount of water retained at pF 1.7-2.7 is 5-50 mL per 100 mL of granular plant growth;
A water retention amount of 5 to 50 mL of pF 1.7 to 2.7 per 100 mL of the granular plant growing body is achieved by combining with a porous granular material having a continuous pore structure;
A water retention amount of 5 to 50 mL of pF 1.7 to 2.7 per 100 mL of the granular plant growing body is achieved by making the granular plant growing body porous;
The porous plant growth body is made porous by freeze-drying at the time of production of the granular plant growth body, or by adding a hydrophilic surfactant during the production of the granular plant growth body and gelling after foaming. Is;
The granular plant growing body contains a cation exchange filler and an anion exchange filler;
The cation exchange filler is selected from the group consisting of zeolite, smectite mineral, mica mineral, cation exchange resin and humus, and the anion exchange filler is hydrotalcite, manaceite, pyroaulite, sjoglenite, Selected from the group consisting of patina, allophane, imogolite, kaolin and anion exchange resin;
The porous powder having the continuous pore structure is selected from the group consisting of foam glass and polymer porous material;
It is desirable.

  According to the present invention, in a granular plant growth body containing a cation exchange filler and an anion exchange filler in a granular alginate gel, the particle size, the cation exchange capacity and the anion exchange capacity are defined within a specific range. By doing so, it has excellent fertilizer retention with high cation exchange capacity and anion exchange capacity, excellent water retention capacity for water that is easily absorbed by plants, and high ventilation in a short time even when kept saturated. It is possible to provide a granular plant breeding body having excellent air permeability that returns to the sex state.

Plant growth requires cations such as K ⁺ , Ca ²⁺ , Mg ^2+, etc. If there is no ability to retain these nutrients, for example, nutrients initially supplied with chemical fertilizers flow down with water as they are. As a result, the plant cannot be used. Natural soil has these adsorption capacities, but when using a polymer material or the like, these capacities need to be artificially added. In addition, nitrogen is an essential element for plant growth, but some species cannot be absorbed as ammonia nitrogen by cation, but can be absorbed only by nitrate nitrogen by anion. In addition to the capability, anion adsorption capability is also required. In the soil, the nitrogen state adsorbed on the cation exchanger as NH ₄ ⁺ is also converted to NO ₃ ⁻ by microorganisms such as nitrifying bacteria in the soil, so the anion adsorption ability may be small. In the artificial soil in which NO exists, it is necessary to directly adsorb NO ₃ ⁻ , and a large anion adsorption ability is required.

Soil water exists around the surface of the soil particles, and continuously exists from the moisture absorption water that exists inside the soil particles to the gravity water that exists outside the soil particles. Specifically, this is due to the difference in the adsorption power, and from the one with the largest adsorption power, the order is hygroscopic water, capillary water, and gravity water. The pF value represents the force (suction pressure) for separating the water adsorbed on the soil by the height of the water column, and specifically, the following formula:
pF = log h
Is a common logarithm of the soil water suction pressure h (cm) expressed in terms of the height of the water column. When the height h of the water column is 1 cm, it corresponds to 98.07 Pa. For example, pF2.0 represents the moisture state adsorbed by a force corresponding to the pressure of a water column having a height of 100 (10 ² ) cm. Moreover, the state where there is no air in the pores in the soil and filled with water is pF0, and the case where only water combined with the soil is present in the heat-dried state at 100 ° C. is pF7.

  Moisture that can be absorbed by the plant from the roots, when it rains or irrigates, and when the downward movement of water due to gravity becomes very small, the plant begins to wither from the water that usually remains after 24 hours (usually pF1.7). Water up to point (pF3.8). Therefore, when the value decreases from pF1.7, air in the soil becomes deficient due to moisture damage, and when the value increases from pF3.8, moisture cannot be absorbed and die.

  Furthermore, among the water that can be absorbed by the plant from the roots, the water of pF1.7 to pF2.7 is called easy water, the plant can easily absorb water, the growth becomes good, and other pF The water of the value is called difficult water, and it becomes difficult for the plant to absorb water, and it does not die but grows. As described above, it is generally said that plants can easily absorb moisture from pF1.7 to pF2.7. Therefore, in the present invention, the volumetric water content per 100 mL of plant growth body as the water retention amount in the range of pF 1.7 to 2.7 is used.

  About the said water retention, not only the pore diameter of a plant breeding body, the porosity, etc. are prescribed | regulated, but the holding | maintenance amount of the water | moisture content which a plant can absorb easily from a root is prescribed | regulated to the specific range. For example, even if the pore diameter and porosity of the plant breeder are defined assuming sufficient water retention, water that is drained by gravity, difficult water that is difficult for the plant to absorb, and moisture combined with soil When it contains, it will be insufficient as the water | moisture content which a plant can utilize, and it will become inadequate as the water retention of a plant breeding body. Therefore, in the present invention, the water retention amount in the range of pF 1.7 to 2.7, which is the amount of water that can actually be used by the plant, is 5 to 50 mL, preferably 7 to 40 mL, per 100 mL of the granular plant growth body, More preferably, it is 10 to 40 mL. If the water retention amount is less than 5 mL per 100 mL of the granular plant growing body, it is difficult to retain moisture that is easily absorbed by the plant over a long period of time, and if it exceeds 50 mL, the air permeability in the water retention state deteriorates and the plant grows. It becomes difficult.

  The granular plant growth body of the present invention is required to contain a cation exchange filler and an anion exchange filler in a granular alginate gel formed from an alginate and a polyvalent metal ion.

The method for producing the granular plant growing body is as follows:
(A) mixing a cation exchange filler and an anion exchange filler with an alginate aqueous solution and stirring to form a mixture;
(B) A step of dropping the obtained mixed liquid into an aqueous polyvalent metal ion solution to form gelled particles, and (c) a step of washing and drying the obtained gelled particles.

  Examples of the cation exchange filler used in the granular plant growth body of the present invention include smectite minerals such as zeolite and montmorillonite, mica minerals, vermiculite, humus, cation exchange resins, and the like. Examples of the resin include weakly acidic cation exchange resins and strongly acidic cation exchange resins.

  The compounding amount of the cation exchange filler is desirably 2 to 40 parts by mass, preferably 5 to 40 parts by mass, and more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the alginate aqueous solution. If the blending amount of the cation exchange filler is less than 2 parts by mass, sufficient ion exchange properties cannot be expressed, and if it exceeds 40 parts by mass, it becomes difficult to produce a granular alginate gel.

  Examples of the anion-exchange filler used in the granular plant growth body of the present invention include natural layered composites having double hydroxides as main skeletons such as hydrotalcite, manaceite, pyroaulite, sjoglenite, and patina. Examples include hydroxides, synthetic hydrotalcite and hydrotalcite-like substances, clay minerals such as allophane, imogolite and kaolin, anion exchange resins, etc. As the above anion exchange resins, weak acid anion exchange resins, strong acid anions Examples thereof include ion exchange resins.

  The amount of the anion exchange filler is desirably 2 to 40 parts by mass, preferably 5 to 40 parts by mass, and more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the alginate aqueous solution. If the blending amount of the cation exchange filler is less than 2 parts by mass, sufficient ion exchange properties cannot be expressed, and if it exceeds 40 parts by mass, it becomes difficult to produce a granular alginate gel.

  Examples of the alginate aqueous solution used in the granular plant growing body of the present invention include sodium alginate, potassium alginate, ammonium alginate and the like. The concentration of the alginate aqueous solution is 0.1 to 5%, preferably 0.2 to 5%, and more preferably 0.5 to 3%. If the concentration of the alginate aqueous solution is less than 0.1%, an alginate gel is hardly formed, and if it exceeds 5%, the viscosity becomes too high, and stirring during mixing of the filler and dropping of the mixed solution become difficult.

  In the manufacturing method of the said granular plant growth body of this invention, in the said process (a), the said cation exchange filler and the anion exchange filler are mixed and stirred in the alginate aqueous solution, In the step (b), gelled particles are formed by dropping into the polyvalent metal ion aqueous solution.

  Examples of the polyvalent metal ion aqueous solution used for the granular plant growth body of the present invention are not particularly limited as long as it is a divalent or higher metal salt aqueous solution that basically reacts with an alginate and causes gelation. Multivalent metal chloride solutions such as calcium, barium chloride, strontium chloride, nickel chloride, aluminum chloride, iron chloride, cobalt chloride, multivalent metals such as calcium nitrate, barium nitrate, aluminum nitrate, iron nitrate, copper nitrate, cobalt nitrate Examples thereof include a metal nitrate aqueous solution, a polyvalent metal lactate aqueous solution such as calcium lactate, barium lactate, aluminum lactate and zinc lactate, and a polyvalent metal sulfate aqueous solution such as aluminum sulfate, zinc sulfate and cobalt sulfate. The concentration of the polyvalent metal ion aqueous solution is 1 to 20%, preferably 2 to 10%, more preferably 5 to 10%. If the concentration of the polyvalent metal ion aqueous solution is less than 1%, an alginate gel is hardly formed. If it exceeds 20%, it takes time to dissolve the metal salt, and an excessive material is used, which is not economical.

  The alginate such as sodium alginate is a neutral salt in which the carboxyl group of alginic acid is bonded to Na ions, and alginic acid is water-insoluble but water-soluble. When a polyvalent metal ion such as Ca ion is added to the aqueous solution of sodium alginate, ionic crosslinking occurs and gelation occurs. The above properties of alginate and polyvalent metal ions are well known, and using this, sodium alginate is widely used as a physical property improving agent such as a thickener, gelling agent, and stabilizer. .

  The granular plant breeding body of the present invention obtained as described above has a particle size of 0.2 to 6 mm, preferably 0.5 to 5 mm, more preferably 1 to 5 mm. When the particle size of the granular plant growing body is smaller than 0.2 mm, the pores between the granular bodies become small, and the water retained in the pores is strongly retained by the capillary force. It becomes difficult to absorb the moisture in the inside, the drainage performance is lowered, and it becomes difficult to absorb oxygen in the root air. Moreover, when the particle size of the granular plant growing body exceeds 6 mm, the pores between the granular plant growing bodies become large, the amount of water that the plant easily absorbs decreases, and the plant does not flow down for a long time. The amount of water that can be used is reduced, and the supportability such as preventing the plant from falling down is reduced.

  The said particle size is the viscosity of the liquid mixture at the time of dripping in the process (b) of the manufacturing method of the said granular plant growth body, and the cation exchange filler and anion exchange filler in the liquid mixture in a process (a). The particle size can be adjusted if the viscosity of the mixed solution is low, and the particle size becomes small if the amount of the filler is small. In the present specification, the particle size of the granular plant growing body is adjusted by classification with a screen mesh or the like.

  The granular plant growth body of the present invention is required to have a cation exchange capacity of 5 meq / 100 mL or more, preferably 7 to 50 meq / 100 mL, more preferably 10 to 50 meq / 100 mL. When the cation exchange capacity is less than 5 meq / 100 mL, sufficient ion exchange cannot be achieved, and even if nutrients are added, it flows down early due to irrigation. Moreover, when the said cation exchange capacity is larger than 50 meq / 100 mL, an extra material will be mixed and it is not economical.

  The granular plant growing body of the present invention is required to have an anion exchange capacity of 5 meq / 100 mL or more, preferably 7 to 50 meq / 100 mL, more preferably 10 to 50 meq / 100 mL. When the anion exchange capacity is less than 10 meq / 100 mL, sufficient ion exchange cannot be achieved, and even if nutrients are added, it flows down early due to irrigation or the like. On the other hand, if the anion exchange capacity is larger than 50 meq / 100 mL, extra materials are mixed, which is not economical.

  In the granular plant growth body of the present invention, as described above, by adjusting the particle size of the granular plant growth body within the above range, the pores between the granular plant growth bodies are adjusted, and the plant absorbs them. It is possible to control the amount of water retained as easy-to-use water and to ensure necessary air permeability. If the granular plant growth body of the present invention has many pores that can hold water of pF1.7 to pF2.7, a larger water retention amount can be obtained. As a method for achieving such a water retention amount, the above-mentioned granular plant growth body is combined with a material having such pores, that is, a porous powder body having a continuous pore structure; and the granular plant growth body itself. There is a method of making it porous. As a method for making the granular plant growth body itself porous, vacuum freeze-drying at the time of production of the granular plant growth body, or by adding a hydrophilic surfactant at the time of production of the granular plant growth body and gelling after foaming There is a method, specifically, in the step (c) of the production method of the granular plant growth body of the present invention, a method using vacuum freeze-drying; the above step of the production method of the granular plant growth body of the present invention ( In a), a method of further mixing a foaming agent may be mentioned. Further, just for the purpose of water retention capable of retaining a large amount of water of pF1.7 to pF2.7, it is possible to obtain a larger water retention by mixing other granular materials.

  When the granular plant growing body of the present invention contains a porous granular material having a continuous pore structure, in addition to the cation exchange filler and the anion exchange filler in the step (a) of the production method, What is necessary is just to add the porous granular material which has the said continuous pore structure. Examples of the porous powder having a continuous pore structure used for the granular plant growing body of the present invention include polymer porous materials such as foamed glass, metal porous body, ceramic porous body and polyurethane foam having a continuous pore structure. Examples include the body. The pore diameter of the porous powder having the continuous pore structure is desirably in the range of 15 to 150 μm. When the pore diameter of the porous granular material is smaller than 15 μm, the moisture retained in the pores is strongly retained by the capillary force, so that the plant becomes difficult to absorb the moisture in the pores, and when the pore diameter exceeds 150 μm. The amount of capillary water in the range of pF 1.7 to 2.7 is reduced, and the water that can be used by plants without flowing down for a long period of time is reduced.

  In the step (c) of the method for producing a granular plant growing body of the present invention, the granular plant growing body itself can be made porous by using a vacuum freeze-drying method. The vacuum freeze-drying can be made porous because water is evaporated (sublimated) and dried in a frozen state under vacuum. The vacuum lyophilization is performed under conditions of a degree of vacuum of 0.5 to 1.0 Pa and a temperature of -5 to -10 ° C for 24 to 48 hours.

  In the said process (a) of the manufacturing method of the said granular plant growing body of this invention, when it contains a foaming agent further in the said process (a) of the said manufacturing method, a cation exchange filler and an anion exchange filler In addition to the above, the above foaming agent may be added. As the foaming agent, a hydrophilic surfactant is preferable. As said hydrophilic surfactant, if it has HLB value 10 or more showing a hydrophilic lipophilic balance, it is possible to make it foam at the time of liquid mixture stirring. The surfactant may be of any type, but anionic or cationic surfactants are not preferred because ions may be generated in an aqueous solution and adsorbed on the ion-exchangeable filler. Specific examples of the hydrophilic surfactant include polyoxyethylene sorbitan monolaurate commercially available from Kao Corporation under the trade name “Leodol TW-L120”; HLB value 16.7, trade name “Leodol TW-S120V”. Polyoxyethylene sorbitan monostearate marketed under the trade name “HLB value 14.9, polyoxyethylene sorbitan monooleate marketed under the trade name“ Leodol TW-O120V ”; HLB value 15.0, trade name“ And polyoxyethylene sorbitan trioleate commercially available from Rhedol TW-O320V; an HLB value of 11.0.

In addition, as described above, cation such as K ⁺ , Ca ²⁺ , and Mg ²⁺ is necessary for the growth of the plant, and if it has no ability to retain these nutrients, for example, it was initially supplied with a chemical fertilizer or the like. The nutrients flow down with the water as it is, and the plant can no longer be used. Natural soil has these adsorption capacities, but when using a polymer material or the like, these capacities need to be artificially added. In addition, nitrogen is an essential element for plant growth, but some species cannot be absorbed as ammonia nitrogen by cation, but can be absorbed only by nitrate nitrogen by anion. In addition to the capability, anion adsorption capability is also required. In the soil, the nitrogen state adsorbed on the cation exchanger as NH ₄ ⁺ is also converted to NO ₃ ⁻ by microorganisms such as nitrifying bacteria in the soil, so the anion adsorption ability may be small. In the artificial soil in which NO exists, it is necessary to directly adsorb NO ₃ ⁻ , and a large anion adsorption ability is required. Therefore, the granular plant growing body of the present invention has both an excellent cation exchange ability and an excellent anion exchange ability, and therefore can be suitably used as artificial soil.

  When the granular plant growing body of the present invention is mixed with another granular body having a continuous pore structure only for the purpose of water retention, the pore diameter of the granular body dedicated for water retention is in the range of 15 to 150 μm. Those with distribution peaks are desirable. If the peak value of the pore size distribution is smaller than 15 μm, the moisture retained in the pores is strongly retained by the capillary force, so that it becomes difficult for the plant to absorb the moisture in the pores. The amount of capillary water in the range of 7 to 2.7 is reduced, and the water that can be used by the plant without flowing down for a long period of time is reduced.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.

(Examples 1-7, 10-14 and Comparative Examples 1-10)
(1) Preparation of liquid mixture The materials of the plant growth body composition shown in Tables 1 to 4 below were stirred for 3 minutes using a household mixer ("SM-L57" manufactured by Sanyo Electric Co., Ltd.) A mixed solution was prepared.

(Note 1) Eco-well's artificial zeolite "Ryukyu Light 600"
(Note 2) Bentonite “Kansai Bentonite” manufactured by Kasanen Industry Co., Ltd.
(Note 3) Reagent hydrotalcite manufactured by Wako Pure Chemical Industries, Ltd. (Note 4) Kaolin clay "NK300" manufactured by Showa Chemical Co., Ltd.
(Note 5) Silica “NCS-3” manufactured by HESS PUMICE PRODUCT
(Note 6) Sodium alginate, a reagent manufactured by Wako Pure Chemical Industries, Ltd. (Note 7) Foamed glass commercially available under the trade name “Supersol” from Trim Co., Ltd. (average pore size 60 μm)
(Note 8) Polyurethane foam “AC Sponge U” manufactured by AC Chemical Co., Ltd.
(Note 9) Surfactant A: polyoxyethylene sorbitan monolaurate commercially available from Kao Corporation under the trade name “Leodol TW-L120”; HLB value 16.7
(Note 10) Surfactant B: Polyoxyethylene sorbitan monostearate marketed by Kao Corporation under the trade name “Leodol TW-S120V”; HLB value 14.9
(Note 11) Surfactant C: polyoxyethylene sorbitan trioleate commercially available from Kao Corporation under the trade name “Leodol TW-O320V”; HLB value 11.0
(Note 12) Surfactant D: Sorbitan monopalmitate commercially available from Kao Corporation under the trade name “Leodol SP-P10”; HLB value 6.7
(Note 13) Surfactant E: Glycerol monostearate commercially available from Kao Corporation under the trade name “Leodol MS-60”; HLB value 3.5

(2) Production of granular plant growth body Using a measuring pipette, the mixed liquid obtained as described above is poured into a 5% calcium chloride aqueous solution as a polyvalent metal ion aqueous solution at a rate of 1 drop / second. It was dripped slowly. After the dropped droplets gelled, the gelled particles were collected, washed with water, dried in a dryer at 55 ° C. for 24 hours, and then adjusted to a particle size of 2 mm over and 4 mm under using a screen mesh. A granular plant growth body was produced. However, in Comparative Examples 5 and 6, the dropping speed was increased to about 3 mL / second, dropped so as to be continuously connected, gelled after the dropped liquid was thinly connected in a fibrous state, and then gelled. The collected fibrous material was collected, washed with water, dried in a dryer at 55 ° C. for 24 hours, finely ground in a mortar, and adjusted to 75 μm over and 106 μm under using a screen mesh and used as a sample. . In Comparative Examples 2 and 4, the mixed liquid was extruded with a dropper in a polyvalent metal ion aqueous solution, and the gelled to a predetermined size in the liquid was collected, washed with water, and dried in a dryer at 55 ° C. for 24 hours. After that, a screen mesh adjusted to 8 mm over and 10 mm under was used as a sample.

(Example 8)
Drying in a dryer at 55 ° C. for 24 hours was performed by freeze drying (“EYELA FDU-1100” manufactured by Tokyo Rika Kikai Co., Ltd.) and square dry chamber (“EYELA DRC-1100 manufactured by Tokyo Rika Kikai Co., Ltd.). A granular plant growth body was prepared in the same manner as in Example 1 except that vacuum freeze-drying (temperature −10 ° C., vacuum degree 0.5 Pa, drying time 48 hours) was used.

Example 9
Drying in a dryer at 55 ° C. for 24 hours was performed by freeze drying (“EYELA FDU-1100” manufactured by Tokyo Rika Kikai Co., Ltd.) and square dry chamber (“EYELA DRC-1100 manufactured by Tokyo Rika Kikai Co., Ltd.). A granular plant growth body was prepared in the same manner as in Example 1 except that vacuum drying (temperature 20 ° C., degree of vacuum 0.5 Pa, drying time 48 hours) was used.

  About the obtained granular plant growth body, the cation exchange capacity, the anion exchange capacity, the gas phase rate, the water retention amount at pF 1.7 to 2.7 and the radish growth ability were measured or evaluated. It shows in Tables 5-8. Test methods and evaluation methods are as follows.

(Test method and evaluation method)
(1) Cation exchange capacity Samples for measuring the cation exchange capacity were obtained by using the extract of each granular plant growth produced using a general-purpose extraction / filtration device "CEC-10 Ver.2" manufactured by Fujihira Kogyo Co., Ltd. As described above, the cation exchange capacity of each granular plant growing body was measured by a soil / crop body comprehensive analyzer “SFP-3” manufactured by Fujihira Kogyo Co., Ltd.

(2) Anion exchange capacity After adding 20 mL of 0.05M calcium nitrate solution to 2 g of sample and stirring for 1 hour, the solution was centrifuged (room temperature, 10,000 rpm, 1 minute), and then the supernatant was separated. Absorbance at a wavelength of 410 nm was measured, and the adsorption amount per weight of nitrate nitrogen was calculated from the concentration difference between the obtained calcium nitrate concentration and the 0.05 M calcium nitrate solution, and converted into specific gravity. Anion exchange capacity (AEC) was used.

(3) Amount of water retained at pF 1.7 to 2.7 A hole for drainage is made in the bottom of a polyethylene cup with a capacity of 500 mL, and sand (particle size 2 to 5 mm) is spread on the bottom, so that water does not collect on the bottom. A container was prepared. The obtained plant-grown body (500 mL) was sufficiently absorbed with water, and a capillary saturated state was used as a sample, and the container was filled so as not to lose its shape. Insert and fix a pF meter into the filled porous fine particles or plant growth body, measure the pF value and volumetric water content of the sample every 24 hours, and plot the capillary force and water content as the water retention capacity. A water retention curve was created, and the water retention amount was determined from the volumetric water content in the capillary force range corresponding to pF 1.7 to 2.7. The measuring method of the said pF value and volume moisture content is as follows.
(A) pF value The pF value was measured using a pF meter (tensiometer) "DIK-8343" manufactured by Dairika Chemical Industry.
(B) Volume moisture content The volume moisture content VWC was determined by calculation from the following equation, where Wp was the mass when the dried plant mass Wd and the pF value were measured.

(4) Gas phase rate Obtain the volumetric water content at pF1.5 from the moisture retention curve created in (3) above, create the moisture content of the sample accordingly, and set the created sample in the digital real volume meter The gas phase rate at pF1.5 is automatically measured. As the measuring device, a digital real volume measuring device “DIK-1150” manufactured by Dairika Chemical Co., Ltd. was used. A larger gas phase ratio value indicates better air permeability.

(5) Radish growth (i) Radish growth 1
A hole for drainage is opened on the bottom of a polyethylene cup with a capacity of 300 mL, and sand (particle size 2 to 5 mm) is laid on the bottom to prevent water from accumulating on the bottom of the cup. After seeding one seed of radish (red king), giving sufficient moisture and germination, 500 times “hyponica liquid fertilizer (two-component type)” manufactured by Kyowa Co., Ltd. once every five days 30 mL of the diluted product was supplied as nutrient, and 30 mL of tap water was supplied every day during that period, and the growth of radish was evaluated at N = 3 according to the evaluation criteria shown below.
(Evaluation criteria)
○: Growing in the same manner as open-air cultivation, good growth △: The true leaves do not grow large, and the growth is slow.

(Ii) Radish growth 2
The radish viability was evaluated at N = 3 in the same manner as the radish viability 1 except that tap water was not supplied.

(Test results)

  As apparent from the results of Tables 5 to 8, the granular plant growth bodies of the present invention of Examples 1 to 14 have both high cation exchange capacity and anion exchange capacity as compared with Comparative Examples 1 to 10. It has excellent fertilizer retention and has a large water retention amount at pF 1.7 to 2.7 which can be easily absorbed by plants, and the radish growth is very excellent.

  Moreover, among Examples which are superior in performance to Comparative Examples, Examples 6 to 7 using a porous powder having a continuous pore structure, Example 8 in which the drying step is vacuum freeze-drying, and HLB value as a foaming agent Examples 10 to 12 using a hydrophilic surfactant having 10 or more have a high water retention amount in pF 1.7 to 2.7, and only supply liquid fertilizer once in 5 days when tap water is not supplied. The results were very excellent in the growth 2 of radish. That is, the water supply frequency can be further reduced by improving the water retention.

  On the other hand, in the comparative example 1 which does not use an anion exchange filler, the anion exchange capacity was very low and the growth of radish was very bad. In Comparative Example 2 in which the particle size of the granular plant growth body is larger than that in Comparative Example 1, the pores between the granular plant growth bodies become large and the water retention decreases, and the radish growth is worse than in Comparative Example 1. Met.

  In Comparative Example 3 in which no cation exchange filler was used, the cation exchange capacity was very low, and the radish growth was very poor. In Comparative Example 4 in which the particle size of the granular plant growth body is larger than that of Comparative Example 3, the pores between the granular plant growth bodies become large and the water retention decreases, and the radish growth is worse than in Comparative Example 3. Met.

  In Comparative Examples 5 to 6 in which the particle size of the granular plant growing bodies is very small, the pores between the granular plant growing bodies become small, and it becomes difficult for the plants to absorb moisture in the pores due to the capillary force, and the drainage performance decreases. Therefore, the growth of radish was very bad. In Comparative Example 4 in which only silica was used as the filler, the anion exchange capacity was very low, and the radish growth was very poor.

  In Comparative Examples 7 to 8 in which kaolin clay powder and silica powder were used as the other fillers without using the cation exchange filler and the anion exchange filler, the cation exchange capacity and the anion exchange capacity were very low. The growth of radish was poor.

  In Comparative Examples 9 to 10 using a porous granular material having a continuous pore structure without using a cation exchange filler and an anion exchange filler, although water retention is excellent, cation exchange capacity and anion The exchange capacity was very low and the radish growth was poor.

Claims (7)

From an alginate gel containing a cation exchange filler and an anion exchange filler, characterized by having a particle size of 0.2 to 6 mm, a cation exchange capacity of 5 meq / 100 mL or more and an anion exchange capacity of 5 meq / 100 mL or more A granular plant breeding body.   The granular plant growth body of Claim 1 whose water retention in pF1.7-2.7 is 5-50 mL per 100 mL of granular plant growth body.   The granular plant growth body of Claim 2 achieved by combining the water retention amount in pF1.7-2.7 of 5-50 mL per 100 mL of the said granular plant growth body with the porous granular material which has a continuous pore structure.   The granular plant growth body of Claim 2 achieved by making the granular plant growth body itself porous by 5-50 mL of pF1.7-2.7 per 100 mL of the said granular plant growth body.   Porous formation of the granular plant growth body is achieved by freeze-drying at the time of production of the granular plant growth body, or by adding a hydrophilic surfactant during the production of the granular plant growth body and gelling after foaming. The granular plant breeding body according to claim 4 which is done. The cation exchange filler is selected from the group consisting of zeolite, smectite mineral, mica mineral, cation exchange resin and humus, and the anion exchange filler is hydrotalcite, manaceite, pyroaulite, sjoglenite, patina, allophane, imogolite, is selected from the group consisting of kaolin and an anion exchange resin, according to claim 1 particulate plant growing body according.   The granular plant breeding body according to claim 3, wherein the porous granular material having the continuous pore structure is selected from the group consisting of foamed glass and a polymer porous body.