JPH0446105A - Soil antimicrobial material for plant - Google Patents

Abstract

PURPOSE:To obtain a soil antimicrobial material for plant having strong fungicidal action to a plant pathogenic fungus and causing no pollution of agricultural chemicals by flow into ground water or river by retaining an antimicrobial ceramics containing a specific antimicrobial metal ion in a specific retaining material. CONSTITUTION:An antimicrobial ceramics, preferably calcium phosphate based ceramics, especially hydroxyapatite containing an antimicrobial metal ion selected from silver, copper and zinc is carried on a retaining material selected from a sheet, mat, sponge or active carbon fiber, preferably the active carbon fiber at an amount of 1-30 wt.% to provide the safe soil antimicrobial material capable of efficiently sterilizing a pathogenic fungus in soil because of strong fungicidal effects to the plant pathogenic fungus and simultaneously free from the fear of residual agricultural chemical because it is hardly absorbed into the plant and further causing no problems of pollution by agricultural chemical because it is not dissolved and dispersed in water.

Description

Detailed Description of the Invention (Field of Industrial Application) Although the present invention has a strong bactericidal effect against plant pathogens, it does not dissolve or disperse due to rain or water spraying and will not flow into groundwater or rivers, so it can be used. It relates to an antibacterial material for soil for plants that does not cause the problem of pesticide contamination, and more specifically, a metal with bactericidal properties, that is, at least one metal or metal ion selected from silver, copper, and zinc. By supporting ceramics and molding them and placing them in the root soil of plants, or by holding the ceramics in mats, sponges, or activated carbon fibers and placing them in the root soil, plants can be protected from pathogens. , relates to antibacterial soil materials for plants that do not cause pesticide contamination.

(Prior art) Pathogens in the soil can cause seedling damping-off and Aiseki disease in open fields, greenhouses, or hydroponic cultivation of vegetables, fruits, plants, trees, etc.
Root necking disease of daikon radish, turnip, Chinese cabbage, etc. or common root disease of Japanese radish caused by Aphanomyces bacteria, black spot disease of melon caused by Monosborascus fungi, rice seedling damping-off disease caused by Fusarium and Rhizoctonia fungi, and churi 7 disease caused by Phytophusora fungi. Phytophthora blight, turf leaf disease caused by Bicillum fungi, spring baldness of grass caused by Bicillum fungi and Rhizoctonia fungi,
Many diseases are caused by pathogenic bacteria in the soil, such as underground rot of coniferous seeds caused by Lacodium fungi. Copper, inorganic organic copper salts, thiuram, copper,
Sterilizing and antibacterial agents such as oxacyxyl, dithianone/copper, mancozeb, cabtane/fosetyl, TPN, guazatine, iprodione, cabtane, mefronil, and polyoxin are used. In addition to these fungicides, herbicides and insecticides are also used in large quantities as agricultural chemicals.

For this reason, there are concerns about the effects of residual pesticides on the human body, and in recent years, pesticide contamination of drinking water due to the large use of pesticides at golf courses has become a particular problem. On the other hand, plants also suffer from diseases caused by pesticides, and there have been reports of gray mold on eggplant caused by pesticide-resistant bacteria, and plant growth problems caused by copper. or,
Fertilizers used in large quantities at golf courses also flow into agricultural water, causing eutrophication and causing agricultural problems.
It is having a negative impact on the fishing industry.

(Problem B to be solved by the invention) The present invention exhibits a strong bactericidal effect against plant pathogenic bacteria, so it efficiently sterilizes pathogenic bacteria in the soil, and since it is hardly absorbed by plants, it is effective against IC and pesticide residues. The main purpose of this material is to provide a safe soil antibacterial material for plants that does not cause the problem of pesticide contamination because it has no self-containing properties and has no ability to dissolve or disperse in water, and also because it strongly adsorbs various substances. The second objective is to provide an antibacterial material for soil for plants that absorbs and retains fertilizers when applied, and is difficult to elute and disperse into water to generate eutrophic agricultural water.

(Means and actions for solving the problem) As mentioned above,
Pathogens in the soil cause disease in plants. This prevention
Various disinfectants are used for treatment in the form of liquid solutions (emulsions, powders, granules, etc.), but the drugs dissolve and disperse in water, reducing their effectiveness and making it difficult to use them in large quantities ( Golf courses in particular require a large amount of chemicals as they are used over a large area, causing pesticide contamination and becoming a problem.

On the other hand, it is known that if a powder such as charcoal or activated carbon is mixed with the soil around the roots of plants, the plants will grow well with just a small amount of fertilizer applied. However, charcoal and activated carbon powders are difficult to handle and are particularly difficult to use in areas that require transplanting, such as certain seedlings or lawns.

Therefore, as a result of research into an antibacterial material for plant soil that does not cause side effects such as pesticide contamination and eutrophication of water, the present invention was achieved. That is, the soil antibacterial material for plants according to the present invention contains at least one antibacterial metal selected from silver, copper, and zinc.
Antibacterial ceramics are made by supporting silicon-based or calcium phosphate-based ceramics with metals or metal ions by ion exchange, and the powder or granules are formed or held in sheet mats, sponges, fibrous activated carbon, etc. Since the molded product according to the purpose is used in the soil and water at the roots of plants, it sterilizes the soil and water for a long period of time, protecting the plants from pathogenic bacteria and preventing pesticide contamination by preventing the fungicide from leaching or dispersing into the soil or water. Does not cause problems. In addition, ceramics that support antibacterial metal ions and holding materials such as sheets, mats, sponges, and activated carbon are all porous and absorb applied fertilizer, preventing its dispersion and elution. Effective use is achieved and eutrophication of agricultural water is less likely to occur.

Ceramics that can be used in the present invention include silicic acid-based ceramics such as zeolite, or calcium phosphate-based ceramics such as tricalcium phosphate, dicalcium phosphate, quaternary calcium phosphate, calcium polyphosphate, and apatite-based compounds.Especially, hydroxyapatite has ion exchange ability. , adsorption capacity, and safety. The manufacturing method of antibacterial ceramics is shown below using hydroxyapatite as an example.
Other ceramics can also be manufactured in the same manner. Allow to cool in the air, stir thoroughly, collect crystals that settle after stirring, thoroughly wash with water to remove attached antibacterial metal salts, and dry and dehydrate to obtain antibacterial hydroxyapatite. The amount of antibacterial metal ions supported on hydroxyapatite by ion exchange depends on the amount of metal salt used and the pH of the solution, so if necessary, adjust the pH of the metal salt aqueous solution in advance by adding an acid or alkali. It is also possible to leave it there. Generally, the amount of metal ions supported on hydroxyapatite is 0.
．． It is preferable to adjust the treatment amount to 0.01 to 50%.

The antibacterial hydroxyapatite obtained in this way does not elute or disperse metal ions even when immersed in water, and unlike organic disinfectants, it is stable against heat and is effective even when heated. will not be reduced. The obtained antibacterial hydroxyapatite can be placed as it is or in granular form in the soil at the roots of plants, but if antibacterial hydroxyapatite is used in the soil in powder or granular form, it will cause damage to plants. It is difficult to remove the antibacterial hydroxyapatite from the soil when replanting, adding fertilizer, replacing the antibacterial side, replacing the soil, etc.

Therefore, it is molded or sheeted. Moreover, it is even more preferable to use these holding materials to ensure effective utilization. A commonly used method can be used to hold the antibacterial hydroxyapatite powder in such a holding material. That is, antibacterial hydroxyapatite powder is kneaded with a retaining material or ceramics in the presence or absence of a required amount of commonly used binders such as rubber rubber, methyl cellulose, PMMAXPVA, etc., and molded into the desired shape. or mold and sinter. A sponge is made by kneading antibacterial hydroxyapatite into a foamable resin material and then heating and foaming it. The retained material can be easily produced by a method such as processing a carbon fiber raw material kneaded with antibacterial hydroxyapatite to produce a fibrous material.

The fact that antibacterial hydroxyapatite is resistant to heat makes the molding of these retainers extremely easy.

The amount of antibacterial hydroxyapatite to be kneaded into these holding materials can be arbitrarily selected to some extent, but 0.1% or more based on the holding material is sufficient, and 1 to 30% is good. By placing the retentate obtained in this way in the soil at the roots of plants, pathogenic bacteria in the soil are sterilized.
Excess antibacterial metal ions from the retained material are not eluted or dispersed into the soil, nor are they absorbed into the plant body, so there is no problem of soil contamination with fungicides or residual pesticides; Due to the porosity and adsorption properties of the material, the applied fertilizer will not be leached or dispersed, so eutrophication of water will not occur and the efficiency of fertilizer will be improved.

The present invention will be specifically explained below with reference to Examples.

Example 1) Carefully dig out about 20 cm of soil from a turf meadow where Rhizoctonia bacteria have been confirmed, along with the turf grass.

The bottom 10cm of this soil is 20cm high - 20cm wide.
Place it in a wooden container made of IiI, and on top of it, spread a net made by kneading 5% antibacterial tricalcium lithium containing 5% silver and 1% zinc, measuring approximately 20 cm on each side, 1 m thick, and having a mesh size of approximately 5 cranes. ,
On top of that, spread the remaining top layer of soil (approximately 10 co+) together with turf grass.
0CI11, put it together with turfgrass in a wooden container with -side 30ω (B). Bury these (A) and (B) together with the container in the soil.

Approximately six months later, the presence of diphtonia bacteria in the soil was confirmed.

As a result, diphtonia bacterium was not observed in (A), but was observed in (B).

Example 2) A sponge with a thickness of 1 cI11 and a side of 5 cm kneaded with 1% hydroxyapatite antibacterial agent containing 2% copper was placed in a glass container, and about 5N of distilled bacteria paste containing 0.3% sucrose was added. Cut out square pieces and place in the sterilized container mentioned above. When this container was placed in a constant temperature bath at 25°C and checked for Bicillum bacteria two weeks later, no Bicillum bacteria were detected. When a similar test was conducted using a sponge without antibacterial agents, a large amount of Bicillum bacteria was confirmed.

Example 3) Field soil in which Bicillum bacteria was confirmed is 301 cm in height and 30 cm in diameter.
Fibrous activated carbon, about 20 countries in diameter, about 0.5 t thick, placed in a CI11 glass container with a thickness of about 10 cm and carrying 20% of hydroxyapatite antibacterial agent containing 10% copper on it.
m, weighing about 10 g, and then spread field soil again to a thickness of about 10 cm on top of it (C). The same field soil was placed in a glass container with a height of 30 holes and a diameter of 30 G, approximately 20 cm thick (D), water was sprinkled on these soils (C) and (D), and the soil was kept at a constant temperature of 25°C and humidity of 60%. Put it in a wet tank. After 5 weeks, the soil was taken out and the number of Vicillum bacteria in the soil was measured. As a result, 10 or less Bicillum bacteria were confirmed per 1 g of soil in (C), and 100 or more in (D).

Example 4) Metal ion elution test A net made by kneading 5% of the tricalcium phosphate antibacterial agent containing 5% silver and 1% zinc from Example I), and a hydroxyapatite antibacterial agent containing 2% copper from Example 2). Cut out 1 g of each of the 1% kneaded sponge and the fibrous activated carbon carrying 20% of the hydroxyapatite antibacterial agent containing 10% copper (Example 3), put them in 100m of distilled water, stir for 4 weeks, and then remove the metal ions in the solution. was measured using an atomic absorption spectrophotometer to determine the amount of metal eluted.

As a result, silver is o, o1ppm1pp, zinc is o, 2pp
The content of copper was 0.1 ppm or less, which was below the detection limit in all metal elution measurements, and was a material that did not elute metal.

(Effect of the invention) The antibacterial material for plants according to the present invention uses metal and safe ceramics and does not elute metal, so it can be used in potted plants, flower beds, golf course lawns, vast areas such as mountain forests, etc. Available for use. In addition, it can be used for hydroponic cultivation of daikon radish and tomatoes, etc. In addition to antibacterializing the soil, it can also promote plant growth and has the same effect as a large amount of fertilizer by incorporating a small amount of fertilizer into activated carbon fibers. water pollution caused by fertilizer runoff can be prevented.

Claims (5)

[Claims] (1) Plant soil characterized by holding antibacterial ceramics containing antibacterial metal ions selected from silver, copper, or zinc on a holding material selected from sheets, mats, sponges, or activated carbon fibers. Antibacterial material. (2) The antibacterial material for soil according to claim (1), wherein the retaining material is activated carbon fiber. (3) The antibacterial material for soil according to claim (1) or (2), wherein the ceramic is calcium phosphate based. (4) The antibacterial material for soil according to claim (3), wherein the calcium phosphate ceramic is hydroxyapatite. (5) The amount of antibacterial ceramics retained is 1 to 30 by weight.
% of the soil antibacterial material according to any one of claims (1) to (4).