JP2000135035A - Artificial culture soil for hydroponic culture and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an artificial culture soil for hydroponic culture, capable of maintaining an acidic degree enabling the maintenance in the proper growth states of plants and having excellent practicality and generality by mixing, granulating and calcining natural zeolite, an organic acid, or the like. SOLUTION: This artificial culture soil for hydroponic culture is obtained by mixing finely processed natural zeolite preferably in an amount of 10-40 wt.%, the ground product of a clay mineral such as kaolinite preferably in an amount of 5-50 wt.%, a clay mineral such as brown soil, and the aqueous solution of an organic acid such as sodium citrate preferably in an amount of 2-20 wt.%, granulating the mixture, and then calcining the granules at 600-1,000 deg.C. Two kinds of natural zeolites each having a particle diameter of 100 μm to 2 mm are preferably used in amounts of 5-20 wt.%, respectively, and it is preferable that the artificial culture soil has a function to maintain the pH of a hydroponic culture solution to 6.0-7.2 during a plant growth period on a hydroponic culture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soil for hydroponics and a method for producing the same. More specifically, the present invention relates to a composition of a cultivated soil capable of maintaining the acidity of the cultivated soil in an aqueous solution from a slightly acidic to a neutral range, and is particularly useful for expanding the versatility of plants for hydroponics.

[0002]

2. Description of the Related Art As soil for hydroponics, it is important to maintain stable physical properties and chemical properties.
Conventionally, as clay for hydroponics, clay minerals at 1200 ° C
The granular foam brick for hydroculture foamed and sintered at a high temperature as described above is often used for growing plants because it is porous, has excellent retention of moisture and fertilizer, and has air permeability and irrigation. However, when the foamed sinter is continuously immersed in the liquid used for hydroponic cultivation, the acidity becomes pH
There was a problem that the plant reached a strongly alkaline area of 8.0 or more and could not maintain a proper growth state of the plant, and a rooting state was caused by soaking the rhizome in the solution for a long time. . Furthermore, since high temperature is required for sintering,
There was a problem from the viewpoint of energy saving.

[0003]

In view of the above, in the past, it has been considered to change from clay minerals, which are often used in foamed bricks, to material contents composed of a plurality of components having multiple functions. Nothing satisfies this. In this regard, the present invention maintains an acidity capable of maintaining a proper growth state of a plant when continuously immersed and used in a cultivation solution for hydroponics, and can exhibit its function with a single use, Further, since it can be manufactured at a low temperature, it can contribute to energy saving.

[0004]

That is, the present invention provides a hydroponic cultivation characterized by mixing natural zeolite, crushed clay mineral, soil mineral, and organic acid, granulating and sintering. Artificial cultivation, finely processed natural zeolite 10-40
% By weight, 5 to 50% by weight of a ground clay mineral, 2 to 20% by weight of an aqueous solution of an organic acid, and a mixture obtained by granulating and sintering a mixture composed of a soil mineral, and having a particle size of at least 100.
5 to 20% by weight of each of two types of natural zeolites in the range of μm to 2 mm, and the pH of the hydroponic solution during the long period of plant life during hydroponic cultivation is in the range of 6.0 to 7.2. Preserved, natural zeolites, crushed clay minerals,
Granulate by mixing soil mineral and organic acid aqueous solution, 600 ~ 1
It is manufactured by sintering at 000 ° C.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hydroponic cultivation in the present invention means cultivating a plant in a cultivation environment consisting of a cultivation solution and a hydroponic soil.

The natural zeolite in the present invention includes, for example, clinoptilolite-based zeolite and modellite-based zeolite, and also includes mixtures thereof and other zeolite-based zeolites, such as mordenite and wylakite. Point to. These natural zeolites are ordinance-designated soil improvement materials that are usually available as fine powder, fine powder, and small pieces, and are a type of hydrous aluminum silicic acid. (About 5 to 10 ohm strong) and a characteristic that the cation exchange capacity (CEC) is as large as 200 meq / 100 g. The particle size is 100μ.
It is adjusted to ２2 mm, and two types of the above-mentioned various zeolites are mixed and used in an amount of 5 to 20% by weight to constitute the soil of the present invention. The reason why the two types of zeolites are mixed and used is to reinforce the strength of the constituents during granulation, and the particle size is set in the range of 100 μm to 2 mm.
If it is less than μ, the air permeability is poor, and if it exceeds 2 mm, the strength during granulation is insufficient. Further, the addition amount is set in the range of 5 to 20% by weight, respectively. If it is less than 5% by weight, the cation exchange capacity of the zeolite cannot be sufficiently exhibited, and if it exceeds 20% by weight, the granulation strength is insufficient. Therefore, it is not preferable. In the present invention, such a natural zeolite is used in the range of 10 to 40% by weight based on the whole constitution. In addition,
If the amount is less than 10% by weight, the ion exchange capacity and the like will be reduced.

On the other hand, ground clay minerals are 1: 1 kaolinite, hydrolyzed halloysite, halloysite, 2: 1.
Type of montmorillonite, vermiculite, illite,
It contains 2: 1: 1 type black light, pure crystalline imogolite and amorphous allophane, and is adjusted to have a particle size of 50 μm.
Use in the range of 50%. If the content of the pulverized clay mineral is less than 5% by weight, the composition has insufficient strength, and if it exceeds 50% by weight, the functions of air permeability and water permeation cannot be sufficiently exhibited. Therefore, it is not preferable.

[0008] Further, the soil mineral refers to brown soil, red soil, black soil, yellow soil, and Kanuma soil, which are commonly referred to as soil. In the present invention, red soil and Kanuma soil are particularly preferred because they are lightweight, have many pores, and have a high water retention ability. Such soil minerals may be used alone or as a mixture, and are used as natural zeolite, pulverized clay minerals, and the remaining components of the organic acid aqueous solution described below.

The organic acid aqueous solution to be added to the raw material is used for preparing a buffer solution in the chemical field.
In particular, those used in the acidity range from strong acidity to neutrality are used. For example, sodium phosphate, sodium borate, sodium citrate, sodium tartrate, succinic acid, tartaric acid, lactic acid, citric acid, and the like. Specifically, an aqueous solution whose acidity is adjusted with a pH meter is 2 to 20. Use by weight%. If the content is less than 2% by weight, the composition cannot be sufficiently granulated, and if it exceeds 20% by weight, the composition cannot be molded.

In the present invention, the high-temperature heat treatment is performed by granulating and drying the composite material obtained by mixing the above-mentioned natural zeolite, pulverized clay mineral, soil mineral, and aqueous solution of organic acid at a temperature in the range of 90 ° C. to 105 ° C. Sintering is performed in the range of 1000 ° C. If the heat treatment is too low, the sintering degree of the artificial soil is insufficient and the hardness is low, which is not suitable. Conversely, if the heat treatment is too high, the porosity is lacking, so that fine air permeability and water permeability are necessary. The space is closed and unsuitable. Usually 750
It is preferable to perform sintering in the range of 950 ° C. The heating time varies depending on the material composition of the artificial soil, but usually about 2 to 3 hours is sufficient. In the actual heat treatment time, the time for raising and lowering the heat treatment temperature should also be considered, and the treatment time including these is usually about 10 to 15 hours, which is performed in a known heating furnace. be able to.

[0011] The artificial soil of the present invention obtained as described above,
It has better acidity stability than conventional foam brick, and is suitable for plant growth. This is because a plurality of sintered zeolites are included as a constituent material, and because of its natural porosity, cation exchange ability, and ceramic, far-infrared radiation acts on the rhizome of a plant.

The actual hydroponic cultivation using the artificial soil of the present invention can be performed by various known methods. For example, it can be used from a small-capacity pot type to a large-capacity large planter, and in some cases, it may be used in combination with other granular cultivation and soil improvement materials. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0013]

EXAMPLE 1 The artificial soil according to the present invention was constituted by the following two compositions. <Artificial cultivation soil of the present invention (1)> Composition Morginite zeolite # 70 (manufactured by Nitto Zeolite Co., Ltd.) 500 g 〃 # 1 (〃) 500 g 2: 1 clay mineral (bentonite) 300 g Soil mineral (red soil) 1000 g Organic acid (citric acid at 0.01% concentration) 700 g All particles having an average particle size of 0.1 mm or less are used.2. Manufacturing
Processing Two types of zeolite (powder, fine-grained), clay mineral and soil mineral were thoroughly stirred, and then an organic acid aqueous solution was added and kneaded to granulate to an average particle size of 7 to 8 mm. Then 100 ~
Perform a drying treatment at 105 ° C. for 2 hours, then raise the temperature from normal temperature to 800 to 850 ° C. for about 1 hour, treat at this temperature for 2 hours, and leave for 12 hours by natural heat radiation cooling.
The sintering process was completed. <The artificial cultivation soil of the present invention (2)> Composition The composition was the same as the composition of the artificially cultivated soil (1) of the present invention except that Kanuma soil was used as the soil mineral. 2. Manufacturing / Processing Same as the conditions of the artificial cultivation soil (1) of the present invention.

The artificial soil according to the present invention obtained as described above is
It had the following characteristics. <Artificial cultivation soil (1) of the present invention> Acidity: 5.86 Electric conductivity: 0.04 mS / cm Water retention: 35.2% Dry bulk weight: 0.63 Average particle size: 7.3 to 7.9 mm < The artificial cultivation soil of the present invention (2)> Acidity: 6.07 Electric conductivity: 0.03 mS / cm Water retention rate: 35.5% Dry bulk weight: 0.61 Average particle size: 7.3 to 7.9 mm The measurement was performed according to the following method. * Method of measuring acidity (pH) Distilled water 2.5 times the weight of the dried sintered body is added and mixed, and then left at 25 ° C. for 1 hour. Before the measurement, gently stir and wait for the indicated value to stabilize with a pH meter (HORIBA) and read the pH. * Measurement method of electric conductivity (EC) Five times distilled water is added to dry sintered body weight and mixed.
Read the indicated value with an electric conductivity meter (HORIBA). * Water retention rate measurement method (wet weight-dry weight / wet weight) x 100 = water retention rate (%) Wet weight is the weight when a wet sintered body is put into a sieve container and excess water is removed. Is shown. The dry weight indicates the weight when the sintered body is dried at 105 ° C. for 1 hour. * Measurement method of dry bulk density The ratio of the mass of a dried sintered body to the mass of water of the same bulk capacity. The unit is shown in g / ml. * Acidity / Electric Conductivity Fluctuation Test 50 g of each of the artificial soils (1) and (2) of the present invention is separately placed in a container for plant cultivation and cultivation, and 2.5 times the amount of distilled water (pH: 5.8) is added. Adjusted in addition. Such an aqueous solution 2
Changes in acidity and electrical conductivity after 72 hours of incubation at 3 ° C were measured. As a control, two types of commercially available expanded bricks (for hydroponic cultivation) were used. That is, as a sample 1, a hydrocorn medium grain (trade name, manufactured by Miura Horticulture Co., Ltd.), a sample 2 was a medium size interior ball (trade name, manufactured by JT Agris Co., Ltd.). The results are shown in Table 1.

[0015]

[Table 1]

As is clear from the above test results, it was confirmed that the artificial soil (sintered body) of the present invention maintained an acidity of pH 5.5 to 7.5 within a range suitable for growing plants. Was done. In addition, 0.5 mS / c expressed by electric conductivity
A value of m or less indicates that excessive accumulation of salts has not occurred, which is also an appropriate condition for plant growth. On the other hand, the test samples (1) and (2) are out of the range.

* Evaluation of actual plants (1) Test conditions Plants were placed in a transparent glass container, filled with the artificial soils (1) and (2) of the present invention, and supplied with an appropriate amount of water. The water supply was 20% of the glass container, and water was replenished about once every two weeks. By using a glass container, the growth degree of the rhizome and the presence or absence of a rooted state are confirmed. The cultivation period is
Illumination at 23 ° C. for 12 hours and darkness for 12 hours were performed for 50 days. The cultivation was performed using an illuminated thermostat, and the humidity in the chamber was kept at least 80% or more. The test plant used was Hedera helix of the family Asteraceae. In addition, test samples (1) and (2) were used as control groups. (2) Measurement items The growth degree of the plant body on the first day and 50 days after the cultivation was used as an index by measuring the whole plant weight variation rate and rhizome elongation variation rate. (3) Test results The results are shown in Table 2. The values are average values of each of the four sections.

[0018]

[Table 2]

It can be seen that Hedera cultivated with the artificial soil according to the present invention increased the total weight by 124 to 134% in 50 days. Also, regarding the extensibility of the rhizome, it can be seen that both of the artificially cultivated soils (1) and (2) of the present invention extend to 137 to 154%. Although not shown as numerical values, sufficient branching of the rhizome was confirmed. At the same time, white capillary roots were elongated at the tip of the rhizome and were not rooted. From these results, it was confirmed that the artificial cultivation soil of the present invention, compared with the commercially available test products (1) and (2), maintained normal growth sufficiently in the container at least at the same level.

[0020]

According to the artificial soil of the present invention, it is possible to cultivate the plant from a slightly acidic to neutral region under conditions that are good for the growth of the plant. And until now, with the commercially available soil for hydroponics,
Long-term appropriate growth of plant varieties that were difficult to grow can be expected. That is, it enables maintenance of the acidity of the cultivation solution during hydroponic cultivation, and its value as an artificial soil for growing plants is extremely large. Further, since the firing temperature can be set lower than in the past, there is an energy saving effect.

Claims (5)

[Claims] 1. An artificial soil for hydroponics, characterized by mixing a natural zeolite, a crushed clay mineral, a soil mineral, and an organic acid, granulating and sintering the mixture. 2. Micronized natural zeolite 10 to 40
The artificial soil for hydroponic cultivation according to claim 1, which is obtained by granulating and sintering a mixture composed of 5% by weight, 5 to 50% by weight of a clay mineral pulverized product, 2 to 20% by weight of an aqueous solution of an organic acid, and a balance of soil mineral. . 3. The artificial soil for hydroponics according to claim 1, wherein two types of natural zeolites having a particle size of at least 100 μm to 2 mm are used in an amount of 5 to 20% by weight. 4. The artificially cultivated hydroponic soil according to claim 1, which has a function of maintaining the pH of the hydroponically cultivated solution in the range of 6.0 to 7.2 during the long life of the plant during hydroponic cultivation. . 5. Mixing and granulating a natural zeolite, a crushed clay mineral, a soil mineral, and an organic acid aqueous solution,
A method for producing an artificial soil for hydroponics, characterized by sintering at 0 ° C.