JP2000224917A - Culture medium and cultivation of crop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a culture medium scarcely causing water repellency even when the moisture content of the culture medium is reduced by drying and capable of remarkably reducing the load on operations in spraying of an agrochemical, preparation of the culture medium and control of disease insect pests by including a specific water holding material containing coconut shells and a coated agrochemical granule. SOLUTION: This culture medium contains a water holding material containing coconut shells and a coated agrochemical granule and the true specific gravity of the water holding material measured by a soil three-phase meter is within the range of 1.5-3.5 g/cm3. At this time, the water holding material is preferably granular and the moisture content (X) of the water holding material is preferably within the range of 0<X<=30 wt.%. The coated agrochemical granule preferably has time limit release type sustained release functions comprising a release suppressing period in which the release of the agrochemical components is suppressed for a prescribed time after the application and a release period in which the release of the agrochemical components is sustained after the passage of a prescribed period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a culture medium and a method for cultivating a crop using the culture medium. More specifically, a medium containing a coconut shell-containing water retention material and a coated pesticide granule, wherein the true specific gravity of the water retention material measured by a soil three-phase meter is 1.5 to
A medium characterized by a range of 3.5 g / cm ³ ,
And a method for cultivating a crop using the medium.

[0002]

2. Description of the Related Art In the past, a culture medium, which is a material for cultivating crops such as seedlings, has been produced by farmers themselves using their own natural soil. The work of preparing the medium involves disinfection, addition of fertilizer, adjustment of physicochemical properties such as pH, and the like, and the specific gravity of the soil itself is heavy. For the purpose of reducing this medium production work, in recent years, using soilless medium raw materials, which are relatively lighter than natural soil and contain plant fiber materials such as peat moss and coconut shells as active ingredients, disinfection and fertilizer Cultured soil after addition, adjustment of physicochemical properties such as pH, etc. is sold and widely used.

[0003] On the other hand, pest control, which is an important task for farmers as well as the preparation of soil, involves applying pesticide formulations containing pesticide components in the form of granules, powders, or wettable powders according to the time of occurrence. Was. When the pesticide formulation is a granule, a method of uniformly applying the granule to a paddy field has been adopted, and when the pesticide formulation is a dust or a wettable powder, the dust or wettable powder is directly sprayed on foliage. This weeding work, like the work of preparing the culture medium, was a heavy burden on farmers whose farmers were aging.
In addition, in the pest control work, as described above, since the sprayer directly brings the granular, powdery or liquid pesticide formulation into the paddy field, the sprayer himself sprays the formulation into the body from the mouth or nasal cavity at the time of spraying. It was dangerous work because it could be sucked.

[0004]

However, a soilless medium containing the above-mentioned plant fiber material as an active ingredient is lighter than a medium containing natural soil as a main component. Further weight reduction is achieved by lowering the moisture content by drying. However, when the weight of the medium is reduced by drying, there is a problem that the medium becomes water-repellent and inhibits water absorption and water retention as the medium.
Therefore, conventionally in a medium containing plant fiber material,
For the purpose of not exhibiting water repellency, it was necessary to previously adjust the water content of the medium to 40 to 60% by weight. For this reason, in a soilless medium containing a plant fiber material as an active ingredient, sufficient weight reduction has not been achieved.

[0005] Further, for the purpose of reducing the pesticide spraying work and improving the safety during the spraying work, coated pesticide granules in which pesticide particles are coated with a coating material have been developed, and seedlings using the coated pesticide granules have been developed. Raising seedling cultivation soil for paddy rice containing time-release coated pesticide granules disclosed in JP-A-9-233952 as a material for horticulture containing time-release coated pesticide granules disclosed in JP-A-10-4783 Seedling culture is being developed. However, culture media containing these coated pesticide granules need to be brought directly to paddy fields by farmers,
Taking this point into account, it is difficult to say that the reduction of the work load was sufficient.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned problems of the prior art, and as a result, have found that a medium containing a water retention material containing coconut shell and a coated pesticide granule is obtained. , The true specific gravity of the water retention material measured by soil three-phase meter is 1.5 ~
If the medium is characterized by a range of 3.5 g / cm ³ , water repellency is unlikely to occur even when the moisture content of the medium is reduced by drying, and the pesticide spraying work is greatly reduced. The present invention was found to be possible, and it was possible to greatly reduce the work load in the preparation of soil culture and the work load in pest control, and completed the present invention based on this finding.

The present invention has the following constitutions (1) to (6). (1) A medium containing a coconut shell-containing water retention material and a coated pesticide granule, wherein the true specific gravity of the water retention material measured by a soil three-phase meter is in the range of 1.5 to 3.5 g / cm ³ . A medium characterized by the following. (2) The medium according to the above item 1, wherein the water retention material is granular. (3) The moisture content (X) of the water retention material is 0% by weight <X ≦ 3.
3. The medium according to the above 1 or 2, which is in a range of 0% by weight. (4) The coated pesticide granule has a timed release type sustained release function comprising a release suppression period in which the release of the pesticide component is suppressed for a certain period of time after application and a release period in which the release of the pesticide component continues after a certain period of time. 4. The culture medium according to any one of the above items 1 to 3, which is a coated pesticide granule. (5) A method for cultivating a crop, comprising using the medium according to any one of the above items 1 to 4.

[0008] The coconut shell used in the present invention is a fibrous material and a woody portion derived from the mesocarp which is obtained by removing the outer rind and the inner rind from the peel of the coconut, and the whole mesocarp is cut and pulverized. A mixture of fibrous materials and woody parts, or a mixture of remaining short fibers and woody parts obtained by removing useful components (rigid fibers and medium and short fibers) from mesocarp called coir dust Means The woody portion is configured to fill the space between the fibers of the mesocarp. In particular, coir dust is generated in large quantities (approximately 60% by weight of the entire mesocarp) in association with the fiber collecting step, which is a useful component, and has conventionally been disposed of. In addition, since coir dust is collected as an unnecessary component in the fiber collecting step, some short and long fibers are mixed in the short fibers and the woody portion.

The manufacturing method is as follows. From the coconut, the juice, endosperm and inner skin are removed.
Dry the mesocarp. The dried outer / mesocarp is soaked in fresh water for 4 to 6 weeks to remove excess tannins and chlorides (without removing water) and to soak. From the soft outer and mesocarp, the rigid fibers and medium and short fibers used for ropes, mats and mattresses are separated, and the by-produced short fibers and woody parts are collected as residues. The collected short fibers and woody parts are hydrated at 80-90.
Although the content is 40% to 50% by weight in the dehydration step, the moisture content is 20% by weight in the sun or hot air drying.
And Further, the dried product is subjected to a fumigation disinfection / sterilization process to remove contamination and adjust the particle size.

[0010] As described above, the residue excluding the rigid and medium and short fibers used for ropes, mats and mattresses is coir dust, which is also called coir, pis, etc., and is conventionally discarded. It is. That is, the present invention leads to effective use of waste.

[0011] The type of palm from which coir dust is collected is not particularly limited. However, since high-quality rigid fibers are collected from coco palms from Sri Lanka, ropes,
It is suitably used for textiles such as mats and mattresses, and emits a lot of coir dust. For this reason, coco palm coir dust from Sri Lanka is excellent in terms of quality and stable supply, and is preferably used.

The water retention material used in the present invention contains the above-mentioned coconut shell and has a true specific gravity (hereinafter referred to as “true specific gravity”) of 1.5 to 3.5 g / cm ^{3 as} measured by a soil three-phase meter. Of the range. The water retention material in the present invention may be composed of only the above-mentioned coconut shell, or may contain components other than the coconut shell. The content of the coconut shell in the water retention material is preferably at least 10% by weight based on the total amount of the water retention material, and if it is less than 10% by weight, the contribution to the weight reduction of the culture medium is small.

[0013] Components other than coconut shells include minerals such as vermiculite, perlite, zeolite and rock wool, bark, wood pulp, rice husk, sawdust, charcoal and other vegetation, water-absorbing polymers, and vegetable fibers such as peat moss. Materials can be mentioned. Among these, the vegetable fiber material is relatively inexpensive and has a stable supply, and can be preferably used in the present invention. Since the material such as peat moss exhibits water repellency upon drying, the content ratio (the coconut shell / vegetable fiber material) in the water retention material is 2.0 by weight.
It is preferable that it is above.

The control of the true specific gravity is performed by using
Applying shearing and / or compressive forces by the method
More possible. The true specific gravity of the water retention material is 1.5 g / cm^ThreeNot yet
When full, water repellency when soil is dried to low moisture
And the water absorption / water retention characteristics deteriorate, and the true specific gravity becomes 3.5.
g / cm ^ThreeIf the amount exceeds
And workability deteriorates. A more preferable range of the true specific gravity
The range is 1.6 to 2.5 g / cm^ThreeIt is. True specific gravity of water retention material
To the above-mentioned range, the content of the culture medium by drying
Water repellency when watering, even when moisture content is kept low
Is less likely to occur. Therefore, according to the present invention, the water content of the medium
Can be reduced to the utmost, and the weight of the culture medium is significantly reduced.
Can be achieved.

The shape of the water retention material used in the present invention is as follows:
It is not particularly limited, and may be powdery or granular. However, in the present invention, it is preferable to be granular from the viewpoint of easy handling. Further, a mixture of a granular water retaining material and a powdery water retaining material may be used. The method of granulation is not particularly limited, but is preferably granulated by the following processing method.

Preferred processing methods include extrusion granulation,
Granulation methods such as a compression granulation method, a tumbling granulation method, a spray drying granulation method, a fluidized bed granulation method, a crushing granulation method, a stirring granulation method, and a coating granulation method. Among them, processing by an extrusion granulation method and a compression / crushing granulation method, which are methods capable of applying a shearing force and / or a compressive force, is particularly preferable.
Examples of the extrusion granulation method include a screw type pre-extrusion method, a horizontal extrusion method, a vacuum extrusion method and a combination pretreatment method, a roll type disk die type and a ring die type, a blade type basket type and an oscillary type. Rating type, gear type or cylinder type which is a self-molding type, continuous type or intermittent type which is a ram type, etc.
A tabletting method and a roll pressing method are exemplified.

The shape of the particulate water retaining material obtained by the above-mentioned processing method is not particularly limited, and may be any of a spherical shape, an elliptical spherical shape, a pellet shape, a polyhedral shape and the like. As for the size of the granular water retention material, the average of the longest part is preferably not more than three times the average particle size of the coated pesticide granule mixed with the water retention agent. As a guide, it is preferable that the longest part is 2 to 15 mm even for the largest granular material,
In other words, if it exceeds 15 mm, classification is likely to occur when mixing the water retention material and the coated pesticide granules.

The water content X of the water retention material used in the present invention X
Is not particularly limited, but 0% by weight <X ≦ 3
It is preferably in the range of 0% by weight, and more preferably in the range of 0% by weight <X ≦ 20% by weight. It is industrially difficult to completely reduce the moisture content to 0% by weight because the moisture content easily changes with time due to moisture in the air and the like. On the other hand, when the moisture content exceeds 30% by weight, the moisture contained in the culture medium may adversely affect the release function of the coated pesticide granule. When a slow-release fertilizer whose solubility is chemically adjusted in the medium of the present invention or a coated fertilizer in which the surface of a granular fertilizer is coated with a coating material, the fertilizer component is dissolved and dissolved by the water over time. May elute. The water content in the present invention is determined by the following equation.
It is a value determined from the weight difference before and after drying after drying for an hour. Formula: weight of water contained in water retention material / total weight of water retention material (solid content + moisture) x 100

The coated pesticide granules of the culture medium of the present invention are particles obtained by coating the surface of particles containing pesticides (hereinafter referred to as "core material") with a coating material. Examples of the pesticides include those having an action of miticide, nematicide, etc. in addition to insecticide, sterilization, weeding and plant growth regulation, and further include repellents and attractants. The pesticide used in the present invention is preferably in the form of a solid powder at room temperature, but may be liquid at room temperature. Further, it is preferable that the pesticide used in the present invention has osmotic transferability. Specific examples of the pesticides that can be used in the present invention are shown below, but these are merely examples, and the present invention is not limited thereto. Further, the core material may contain one kind of pesticide or two or more kinds of composite components.

For example, those having an insecticidal action include:
(E) -N ¹ - [(6-chloro-3-pyridyl) methyl] -N ² - cyano -N ¹ - methyl acetamidine (common name: acetamiprid), 1- (6-chloro-3-pyridylmethyl) -N-nitroimidazolidin-2-ylideneamine (generic name: imidacloprid), O, O-diethyl-S-2- (ethylthio) ethyl phosphorodithioate (generic name: ethylthiomethone), 1,3-bis (carbamoylthio)- 2- (N, N-dimethylamino) propane hydrochloride (general name: Cartap),

2,3-dihydro-2,2-dimethyl-7
-Benzo [b] furanyl = N-dibutylaminothio-N
-Methyl carbamate (generic name: carbosulfan),
(2-isopropyl-4-methylpyrimidyl-6) -diethylthiophosphate (generic name: diazinon), 5
-Dimethylamino-1,2,3-trithiane oxalate (generic name: thiocyclam), (E) -N- (6-chloro-3-pyridylmethyl) -N-ethyl-N'-methyl-2- Nitrovinylidene diamine (generic name: nitenpyram), O, O-dipropyl-O-4-methylthiophenyl phosphate (generic name: probafos),

5-bromo-3-secondary-butyl-6
-Methyluracil (generic name: Bromacil), ethyl = N
-[2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl (methyl) aminothio]-
N-isopropyl-β-alaninate (generic name: benfracarb), 2-chloro-4,6-bis (ethylamino) -1,3,5-triazine (generic name: CAT), 3
-(3,4-dichlorophenyl) -1,1 dimethyl urea (generic name: DCMU), 1-naphthyl-N-methylcarbamate (generic name: NAC), 2-isopropoxyphenyl-N-methylcarbamate (generic name: PHC) and the like,

As those having a bactericidal action, diisopropyl-1,3-dithiolan-2-ylidene-malonate (general name: isoprothiolane), 5-methyl-1,2,2
4-triazolo [3,4-b] benzothiazole (generic name: tricyclazole), 1,2,5,6 tetrahydropyrrolo [3,2,1-ij] quinolin-4-one (generic name: pyroquilon), 3 -Allyloxy-1,2-benzoisothiazole-1,1-dioxide (generic name: probenazole) and the like;

Examples of those having a herbicidal action include 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (generic name: atrazine), 1- (2-chloroimidazo [1,2-a] pyridine- 3-ylsulfonyl)
-3- (4,6-dimethoxypyrimidin-2-yl) urea (generic name: imazosulfuron), S-benzyl = 1,
2-dimethylpropyl (ethyl) thiocarbamate (generic name: esprocarb), 2-methylthio-4,6-bis (ethylamino) -s-triazine (generic name: simethrin), S-1-methyl-1-phenyl Ethyl = piperidine-1-carbothioate (generic name: dimepiperate), 1- (α, α-dimethylbenzyl) -3- (paratolyl) urea (generic name: Daimron),

2-chloro-N- (3-methoxy-2-thenyl) -2 ′, 6′-dimethylacetanilide (generic name: phenylchlor), α- (2-naphthoxy) propionanilide (generic name: naproanilide), 4- (2,
4-dichlorobenzoyl) -1,3-dimethyl-5-pyrazolyl-p-toluenesulfonate (generic name: pyrazolate), S- (4-chlorobenzyl) -N, N-diethylthiocarbamate (generic name: benthiocarb), 2
-Benzothiazol-2-yloxy-N-methylacetanilide (generic name: mefenacet);

As those having a plant growth regulating action, 4
'-Chloro-2'-(α-hydroxybenzyl) isonicotinanilide (generic name: inabenfide), (E)-
(S) 1- (4-chlorophenyl) -4,4-dimethyl-2- (1H-1,2,4-triazol-1-yl)
Penta-1-en-3-ol (generic name: uniconazole P), calcium peroxide, (2RS, 3RS) -1-
(4-chlorophenyl) -4,4-dimethyl-2- (1
H-1,2,4-triazol-1-yl) pentane-
3-ol (generic name: paclobutrazol) and the like can be mentioned. Further, the pesticidal active ingredient in the present invention also includes a substance that is synthesized by plants and induces phytoalexin, which is a low-molecular-weight antibacterial substance that accumulates in plants.

The particle size of the core material is not particularly limited.
m or more, preferably in the range of 0.7 to 5.0 mm,
More preferably, it is in the range of 0.7 to 2.0 mm. If the particle size is less than 0.3 mm, it is difficult to coat, and in production, 0.7 to 5.0 mm in terms of easy mixing and handling.
It is preferred that The particle size can be easily selected by using a sieve.

Although the coating material is not limited, any of an organic material and an inorganic material may be selected. Examples of the inorganic material include sulfur, and examples of the organic material include resin. Examples of the resin include olefin polymers, vinylidene chloride polymers, vinyl chloride polymers, diene polymers, waxes, polyesters, petroleum resins, natural resins, oils and fats and modified products thereof, and alkyd resins and phenol resins. And thermosetting resins such as urea resin and melamine resin. Among these resins, an olefin polymer having a small moisture permeability, which is effective in controlling release, can be preferably used. Among them, polyethylene, polypropylene, ethylene-
A propylene copolymer and an ethylene-carbon monoxide copolymer are particularly preferred.

The release function of the coated pesticide granule is not particularly limited, but the coated pesticide granule having the time-release type sustained release function (timed release function) is a pesticide component which is originally applied in the field. Can be preferably used in the present invention, since even if it is contained in a medium in the form of a coated pesticide in a culture medium, phytotoxicity hardly occurs during seedling raising.

The timed release type sustained release function is a release function comprising a release suppression period in which the release of the pesticide active ingredient is suppressed for a certain period of time after application, and a release period in which the release of the pesticide active ingredient is continued after a certain period of time. Specifically, a period from application to the release of 10% by weight of the pesticidal active ingredient in the pesticide particles is referred to as a release suppression period (hereinafter referred to as “d1”).
When a period from the weight% release date to the 90% by weight release date is defined as a release period (hereinafter referred to as “d2”), d1
It means a release function where the ratio of / d2 is 0.2 or more.

The timed release function may be based on any mechanism. Since pesticides are generally poorly soluble in water, the pesticide components inside the coating are destroyed or dissolved in order to be released outside the coating, and the pesticide particles inside the coating are removed from the environment (soil, water, etc.) outside the coating. Etc.).

Specifically, a first coating layer made of a crosslinked isobutylene polymer powder and polyethylene glycol and a second coating layer made of an ethylene-ethyl acrylate copolymer disclosed in JP-A-6-9303 are disclosed. From a first coating layer comprising calcium hydroxide and polyethylene glycol disclosed in JP-A-6-9304, and a maleimide-modified ethylene-ethyl acrylate copolymer and isobutylene-maleic anhydride copolymer. A two-layer coating of a second coating layer, a first coating layer of calcium hydroxide and polyethylene glycol disclosed in JP-A-6-72805, and nylon 6-nylon 66-nylon 1
(2) A two-layer coating of a second coating layer comprising a maleimide-modified terpolymer and isobutylene-maleic anhydride copolymer, a powder of isobutylene-based polymer disclosed in JP-A-6-80514 and polyethylene glycol The first consisting of
A timed release function can be achieved by coating the surface of the core with a coating layer and a second coating layer of a nylon 6-nylon 66-nylon 12 terpolymer. However,
Each of these coatings is composed of two coating layers, and it is preferable that the coating be a single layer from the viewpoint of the complexity of the coating operation and the cost of capital investment for manufacturing equipment.

Examples of coated pesticide granules capable of achieving a timed release function with a single layer film include, for example, JP-A-9-7760.
No. 8, a coated pesticide granule obtained by coating the surface of pesticide particles (core material) composed of at least one or more pesticidal components and at least one or more water-swellable substances with a coating mainly composed of a resin. Can be mentioned.

The amount of the coated pesticide granules to be contained in the medium of the present invention is not particularly limited, but may be, for example, the total amount of the pesticide components to be sprayed during the cultivation period, or the majority thereof. In addition, one kind of coated pesticide granules may be used, and a sustained release function (release pattern and length of release suppression period)
Or two or more kinds of coated pesticide granules having different pesticide components may be used. As a guide of the preferable blending amount of the coated pesticide granule in the medium of the present invention, it is in the range of 20 g or more and 200 g or less per 5000 cm ³ of the water retention material of the medium of the present invention. That is, it means that the weight is 20 g or more and 200 g or less per nursery box (for example, 28 cm × 58 cm × 3 cm) conventionally used in transplant cultivation.
Within this range, the characteristics of the culture medium are not impaired.

The culture medium of the present invention may contain, if necessary, pesticide components other than fertilizers and coated pesticide granules. Fertilizer ingredients include nitrogen, phosphoric acid, potassium, calcium,
There may be mentioned those containing magnesium and a trace element, and the necessary amount may be added to the medium of the present invention according to the use situation. The types and shapes of fertilizers include generalized chemical fertilizers, advanced chemical fertilizers, slow-release fertilizers with chemically adjusted solubility, coated granular fertilizers in which the surface of granular fertilizer is coated with a coating material,
Organic fertilizers, soluble fertilizers and the like can be mentioned.

The pesticides other than the coated pesticide granules include insecticides and fungicides which are required at the time of raising seedlings and which act immediately, and specific examples include Tachigare Ace solution (manufactured by Sankyo Co., Ltd.). it can.

The form of the culture medium of the present invention may be a simple mixture of a powdery and / or granular water retention material and a coated pesticide granule, or may be a whole culture medium molded and integrated. . The method of integrating the entire medium is not particularly limited, and examples thereof include molding with a binder, integral molding with a package made of a plastic bag or the like, and a method of applying pressure and a combination thereof. . The shape of the whole medium is not particularly limited,
It can be in the shape of a plate, a die, a tablet, or the like.

The cultivation method of the present invention is not particularly limited as long as it is a method for cultivating a crop using the medium of the present invention. It may be used as a nursery bed soil at the time of raising seedlings, or may be thrown into the main field. In order to maximize the effects of the medium of the present invention, it is preferable that the medium of the present invention is used as a nursery bed soil when raising seedlings, and the seedlings grown on the bed soil are transplanted and cultivated in this field.

The cultivation method of the present invention is not limited to crops. Specifically, the cultivation method is used for field crops composed of food crops, feed crops, industrial crops, horticultural crops composed of fruit trees, vegetables, flowers, lawns, and the like. be able to. For example, as food crops, rice, wheat, corn, potatoes, legumes, as feed crops, grasses, legumes, root crops for feed, and as industrial crops, taste crops (tea, etc.) and spice crops (pepper, etc.) ), Oil crops (eg sesame), sugar crops (eg sugar beet), fiber crops (eg cotton), fruit trees such as nuts (eg apples), drupes (eg peaches), citrus fruits, tropical fruit trees (eg pineapples) Vegetables can be used for leafy vegetables, root vegetables, fruits and vegetables, and flowers can be used for annual grasses, biannual grasses, prairie grasses, flowering trees and the like.

[0040]

EXAMPLES The present invention will be described below in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In each example, the true specific gravity and other properties were obtained as follows.

1. Method of measuring functions and physical properties (1) Soil three-phase meter (model; DI) manufactured by Daiki Rika Kogyo Co., Ltd.
K-3520) Measurement of Three-Phase Distribution and True Specific Gravity This measurement was performed in accordance with a 100 ml actual volume measurement method. The sample medium to be tested for measurement is
0 ml sample cylinder (manufactured by Daiki Rika Kogyo Co., Ltd., model: DIK
-1801). Sand column method kit (Daiki Rika Kogyo Co., Ltd., model; DIK
After the above is set in −3520) and watering is sufficient,
The water level was PF = 1.5 (water level from the top of quartz sand; 31.6
cm lower). A 100 ml sample cylinder is covered and left for 24 hours in a state of PF = 1.5. Soil three-phase meter (Daiki Rika Kogyo Co., Ltd., model; DIK-
1120), the sample cylinder is set, and the actual volume (V) of the sample medium is measured. Further, measure the total weight (W) of the sample medium with a balance,
It is placed in an oven and dried at 105 ° C. for 24 hours, and the weight of water (M) is calculated from the weight difference before and after drying. According to the following formula, a) gas phase ratio b) solid phase ratio c)
Liquid phase ratio d) True specific gravity was calculated. a) Gas phase ratio (A = Va); Air volume Va = 100−V b) Solid phase ratio (Sν = Vs); Solid phase volume Vs = (W−V) / (d−1) c) Liquid phase ratio (Mν = Vl); water capacity Vl = V−Vs d) true specific gravity (d); d = (WM) / (V−Vl) where V1: water capacity, Vl = M

(2) Maximum Water Retention The maximum water retention used as an index of water repellency and water retention is:
According to the Hilgard method, which is a method for measuring the maximum water volume, a sample medium is filled in a maximum water volume measurement container (capacity: 25 ml), water is absorbed from the bottom, and left for 24 hours. The sample may overflow from the water volume measurement container, and the overflowed sample was completely removed and the weight was measured.) Subsequently, the container was dried in an oven at 105 ° C. for 12 hours, the weight before and after drying was measured, and the following formula (maximum water retention) =
The maximum water retention (g / 25 ml) was calculated from (total sample weight before drying)-(total sample weight after drying). However, in this example, in order to accurately evaluate the water repellency, only the water absorption from the bottom surface was performed, and the water supply from the upper surface was not performed.

(3) Release Function Confirmation Test The release confirmation test measures the time (release start time) until cracks occur in the coated pesticide granules and the coating disintegrates (the inner core material is released to the outside). It was done. The collapse of the coating was confirmed by observation. The specific test was performed according to the following description. Test tube with cap (12mm × 72
mm), 1.5 ml of water was added thereto, and the coated pesticide granule sample described below was further charged one by one per test tube and capped. One hundred tubes (particles) were prepared for each sample, and the number of the disintegrated coated pesticide granules was counted under a constant water temperature of 20 ° C. Observations were made daily for one week from the start of the test, and thereafter every three days. The cumulative release rate is the number of test granules. The cumulative release rate was plotted on the vertical axis and the number of days elapsed on the horizontal axis, and a graph was created by plotting the respective data. The number of days from the start of the test to 10% release was “d1”, and the number of days from then on to 90% release was “d2”.

(4) Storage Stability Test A sample medium was placed in a 0.063 mm-thick polyethylene bag (trade name: Reed frozen storage bag, Lion Co., Ltd.), filled, sealed, and stored at room temperature in a dark place. Left. After three months, the coated pesticide granules were taken out of each sample medium, and a release function confirmation test was performed using 100 grains for each sample medium. From the obtained graph, d
1, d2 was determined.

2. Manufacture of water retention material (water retention material A) 200 L of coir dust (solid content: 12 k
g, moisture content: 36% by weight, φ4 mm pass, coconut shell from Sri Lanka) and ammonia sulfate (Nippon Steel Chemical Co., Ltd.)
150 g, manufactured by Onoda Kagaku Kogyo Co., Ltd., 46% guaranteed phosphoric acid soluble in sulfur.
00g and 60 g of sulfuric acid Kari (manufactured by Chisso Corporation, guaranteed component Kari 50%) were mixed with a ribbon mixer (model: RM-
60, manufactured by Fuji Paudal Co., Ltd.). The above mixture was compression-molded with a disk die roll-type extrusion granulator (disk pelletizer model; F40 / 33-390, manufactured by Fuji Paudal Co., Ltd., die / nozzle diameter: φ2.5 mm), A columnar granulation was obtained. 90 times
Drying was performed with a hot air drier at a temperature of 5 ° C. until the water content became 5% by weight to obtain a water retention material A (10 kg).

(Water Retaining Materials B to D) The moisture content after granulation and drying is 10% by weight (water retaining material B), 20% by weight (water retaining material C), and 30% by weight (water retaining material D). The same operation as in the production of the water retention material A was repeated, except that the water retention material was dried as described above, to obtain the water retention material B, the water retention material C, and the water retention material D (10 each).
kg).

(Water Retention Material E) Coir dust and charcoal (made by Hita Forestry Association, trade name;
No. B / D: 0.29 g / ml, particle size: 2 mm or less) except that a mixture (weight ratio = 3: 1) was used, and the same operation as in the production of the water retaining material A was repeated to obtain a water retaining material E. (10 kg).

(Water retention materials F to H) The moisture content after granulation and drying is 10% by weight (water retention material F), 20% by weight (water retention material G), and 30% by weight (water retention material H), respectively. The same operation as in the production of the water retention material E was repeated, except that the water retention material was dried as described above, to obtain the water retention material F, the water retention material G, and the water retention material H (10 each).
kg).

(Water Retention Material I) The water retention material A was crushed by a crusher (SAMPLE M
30ml / 5m with ILL model SM-1, manufactured by Iuchi Seieido
The water retention material I was obtained by mixing 100 L of the crushed product and 100 L of calcined vermiculite (water content: 5% by weight or less, manufactured by Kyushu Chemical Industry Co., Ltd.) (16 k).
g).

(Water Retention Material J) 200 L of coir dust (solid content: 12 kg, moisture content: 36% by weight, φ4 mm pass,
Sri Lankan coconut shell, 150 g of ammonium sulfate (manufactured by Chisso Asahi Fertilizer Co., Ltd., guaranteed component nitrogen 21%), heavy baking phosphorus (manufactured by Onoda Chemical Industry Co., Ltd., guaranteed component soluble phosphoric acid 4)
6%) and 60 g of sulfuric acid Kari (manufactured by Chisso Corporation, guaranteed component Kari 50%) were mixed with a ribbon mixer (model;
RM-60, manufactured by Fuji Paudal Co., Ltd.). The mixture was dried with a hot-air dryer at 90 ° C. so that the water content was 10% by weight, to obtain a water retention material J (10 kg).

(Water Retentive Material K) The same operation as that of the water retentive material J was repeated except that drying was not performed, and a water retentive material K was obtained by adjusting the water content to 40% by weight (10 kg).

(Water Retentive Material L) Water retaining material L was obtained by repeating the same operation as for water retaining material J except that peat moss (made by Lameque, Canada, moisture content: 10% by weight) was used instead of coir dust. (10 kg).

(Water Retention Material M) 200 L of coir dust (solid content: 12 kg, moisture content: 36% by weight, φ4 mm pass,
Sri Lankan coconut husks are extruded by a disk die roll type extrusion granulator (disk pelletizer model; F40 / 33-39)
0, manufactured by Fuji Paudal Co., Ltd., die / nozzle diameter: φ2.
5 mm) and dried by a hot air dryer at 90 ° C. so that the water content becomes 5% by weight, to obtain a columnar water retaining material M (10 kg). (Water retention materials N to P) Drying so that the moisture content after granulation and drying is 10% by weight (water retention material N), 20% by weight (water retention material O), and 30% by weight (water retention material P), respectively. The same operation as in the production of the water retention material M was repeated, except that the water retention material N, the water retention material O, and the water retention material P were obtained (each 10 kg).
(Water Retention Material Q) Approximately 200 L of coir dust (solid content: 12 kg, moisture content: 36% by weight, φ4 mm pass, Sri Lankan coconut shell) used in water retention materials A and M, was dried with a hot air dryer at 90 ° C. The water retention material Q was obtained by drying so that the rate might be 5% by weight (10 kg). (Water Retaining Material R) Water was added to about 200 L of coir dust (solid content: 12 kg, moisture content: 36 wt%, φ4 mm pass, Sri Lankan coconut shell) used in the water retaining materials A and M, and the moisture content was 50 wt%. Water retention material R was obtained (10 kg). (Water retention material S) Commercially available granular soil for raising rice seedlings (Kureha Chemical Co., Ltd., moisture content 10% by weight)

(Physical Characteristics of Water Retention Material) The true specific gravity and the maximum water retention amount of the above water retention materials A to S were measured by the above-mentioned method, and the obtained results are shown in Table 1.

[0055]

[Table 1]

3. Manufacture of coated pesticide granules 7 parts by weight of Kumiai beam wettable powder 75 (75% by weight of tricyclazole, manufactured by Kumiai Chemical Co., Ltd.), bentonite 7
0 parts by weight, 18 parts by weight of clay, and 5 parts by weight of talc were uniformly mixed in a kneader and kneaded with water. This mixture was extruded and granulated by a screw extruder (a screen diameter of 0.8 mmφ) to obtain a primary agricultural chemical granule. The granulated product is
Rotating disk type granulator (made by Fuji Paudal, Malmerizer Q)
J400). After sieving, dried under a condition of 100 ° C. using a hot air circulating drier, and classified by a vibrating sieve to obtain a 0.8 to 1.4 mm secondary pesticide granule (core material) containing 5% of tricyclazole. Was.

Spouted bed coating apparatus (tower diameter 250 mm, height 3
000 mm), the obtained core material was jetted, and a coating material solution was sprayed on the core material to obtain a coated pesticide granule having a coverage of 20% by weight. The production was performed according to the following method. The coverage is the ratio of the weight (b) of the coating to the coated pesticide granules when the sum of the weight (a) of the pesticide particles (a) and the weight (b) of the coating is 100% by weight.
/ (A + b)]. The coating material dissolving solution is a low density polyethylene (MI = 23, d = 0.91 g / cm)
³ ) A coating material composition comprising 30 parts by weight and 70 parts by weight of talc (average particle size: 5 μm) was added to 1 part of tetrachloroethylene.
It was obtained by stirring and dissolving at 10 ° C. Core material: 3 kg Hot air temperature: 120 ° C. Hot air volume: 4 m ³ / min Spray flow rate: 0.2 kg / min Coating material concentration in coating material dissolving liquid: 2.5% by weight Spraying of coating material dissolving liquid The core material surface temperature is 7
Starting from the point when the temperature reaches 0 ° C, spraying is performed using a one-fluid nozzle so that the product temperature becomes constant at 70 ° C, and then drying is performed under the condition that the coated core material surface temperature is 70 ° C while maintaining the jet state. Performed to obtain coated pesticide granules.

(Release Characteristics of Coated Pesticide Granules) The release function of the coated pesticide granules was confirmed by the method (3) (release function confirmation test) described above. The release of the granules is d1 25
On the other hand, d2 was 7 days, and it was confirmed that the granule had a time-release type sustained release function of d1 / d2 ≒ 3.6.

4. Production of Sample Medium Example 1 A mold of the same size as a paddy rice seedling raising box (inner diameter 28 cm × 58 cm × 3 cm) is filled with 700 g of the water retention material A and uniformly leveled. Subsequently, 50 g of the obtained coated pesticide granule was uniformly and layered to obtain a medium.

Example 2 Example 1 except that water retention material A was changed to water retention material B 740 g.
A medium was obtained in the same manner as described above.

Example 3 Example 1 except that water retaining material A was changed to water retaining material C 830 g.
A medium was obtained in the same manner as described above.

Example 4 Example 1 except that water retaining material A was changed to water retaining material D 950 g.
A medium was obtained in the same manner as described above.

Example 5 Example 1 was repeated except that the water retention material A was changed to 700 g of the water retention material E.
A medium was obtained in the same manner as described above.

Example 6 Example 1 was repeated except that the water retaining material A was changed to water retaining material F 740 g.
A medium was obtained in the same manner as described above.

Example 7 Example 1 was repeated except that the water retaining material A was changed to 830 g of the water retaining material G.
A medium was obtained in the same manner as described above.

Example 8 Example 1 was repeated except that the water retention material A was changed to water retention material H950 g.
A medium was obtained in the same manner as described above.

Example 9 A polyethylene bag (trade name: Unipack L-4, thickness: 0.04 mm, size: 340 mm × 48) containing 700 g of the water retention material I and 50 g of the obtained coated pesticide granule was sealed.
0 mm), sealed, and mixed until uniform to obtain a culture medium.

Comparative Examples 1 to 3 Same as Example 1 except that the water retaining material of Example 1 was changed to J (Comparative Example 1), K (Comparative Example 2), and L (Comparative Example 3), and 400 g of each was used. To obtain a medium.

Comparative Example 4 (Conventional Medium) A polyethylene bag (trade name: Unipack L-4, thickness 0.04 mm, size 340 mm × 4) containing 3000 g of the water retention material S and 50 g of the obtained coated pesticide granule was sealed.
(80 mm), sealed, and mixed until uniform to obtain a medium.

"Physical Characteristics of Sample Medium"
9 and Comparative Examples 1 to 4 were measured and evaluated for the physical properties described above, the weight when filled in a nursery box, and the results obtained are shown in Table 2.

"Measurement of Release of Coated Pesticide Granule in Medium" After production of the sample medium, Examples 1 to 9 and Comparative Examples 1 to 4
To a polyethylene bag with a sealed chuck (trade name: Unipack L-4, thickness 0.04 mm, size 340 mm ×
480 mm) and sealed in 3 kg each.
Each was subjected to a storage stability test. Examples 1 to 8 were put in a bag, sealed, and thoroughly stirred before being tested. Table 2 shows the results.

[0072]

[Table 2]

From Table 2, it was found that Examples 1 to 9 of the product of the present invention were lighter than Comparative Example 4 of the conventional medium, and the water retention was as good or better. Comparative Examples 1 and 3 are light in terms of the total weight of the nursery box, but it is not suitable for cultivation because water repellency is apparent from the maximum water retention and the moisture in the nursery box. The release after storage tended to be slightly faster in Examples 4 and 8, but in the other examples there was little change compared to before storage. Embodiments 4 and 8 are also in the range of variation and have no practical problem, and if this is the case, it is possible to cope with them by shortening the storage conditions, for example, the storage period. on the other hand,
In Comparative Examples 2 and 4, release was promoted. It can be inferred that this is because Comparative Example 4 had a low water content of 10% by weight, but the entire medium was heavy and the water content per volume was large. From these test results, Examples 1 to
9 revealed that the medium of the present invention was lightweight, water-repellent, and excellent in storage stability.

[Cultivation test] The culture media of the present invention, Examples 1 and 5,
Cultivation test was performed using Comparative Example 9 and Comparative Example 2. The test crop was a paddy rice (variety: Hitomebore), sprout seeds were prepared according to a conventional method, and 150 g of the seeds were seeded uniformly and in layers on the surfaces of the seedling boxes of Examples and Comparative Examples. Subsequently, soil was covered with 1000 g of water retention material S. Thereafter, the nursery box was installed in a glass room in Minamata City, Kumamoto Prefecture, and house nursery was performed.
Irrigation was performed as needed to prevent the surface from drying. The state of the seedlings during the seedling raising period was observed at any time. Average daily temperature during nursery 2
0-25 ° C. Other cultivation conditions were performed in accordance with the customary method. The observation results during the seedling raising period are shown in Table 3 and FIG.

[0075]

[Table 3]

From the results shown in Table 3, the test plots using the media of Examples 1, 5, and 9 could grow healthy seedlings without causing any phytotoxicity. In the test plot, the growth rate slowed down from the late stage of seedling raising, and phytotoxicity occurred. After three weeks, the seedlings were completed, and the seedlings grown in the medium of Example 1 were transplanted to paddy fields. As a result, a sufficient control effect was exhibited.

[0077]

The present invention is a medium containing a water retention material containing coconut shells and coated pesticide granules, wherein the true specific gravity of the water retention material measured by a soil three-phase meter is 1.5 to 3.5 g. / Cm ³ , and a method for cultivating a crop using the medium. With the medium of the present invention, even when the moisture content of the medium is reduced by drying, water repellency is unlikely to occur, and it is possible to greatly reduce the pesticide spraying work. The work load in pest control can be greatly reduced. Further, cultivation using the medium enables labor-saving and effective pest control.

[Brief description of the drawings]

Fig. 1 Two weeks after sowing. The left is the medium of Comparative Example J, and the right is the medium of Example 1.

Claims (5)

[Claims] 1. A medium containing a coconut shell-containing water retention material and a coated pesticide granule, wherein the true specific gravity of the water retention material measured by a soil three-phase meter is 1.5 to 3.5 g / cm ³ . A medium characterized by being a range. 2. The medium according to claim 1, wherein the water retention material is granular. 3. The water retention material having a water content (X) of 0% by weight.
3. The medium according to claim 1, wherein <X ≦ 30% by weight. 4. A time-release type sustained release wherein the coated pesticide granule comprises a release suppression period in which the release of the pesticide component is suppressed for a certain period after application, and a release period in which the release of the pesticide component continues after a certain period of time. A coated agricultural chemical granule having a function.
The medium according to any one of the above. 5. A method for cultivating a crop, comprising using the medium according to any one of claims 1 to 4.