JP2002104893A - Coated granular material and method of cultivating crop using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated granular material for total amount base manure able to reduce vegetative disorder of a seedling and a method of cultivation. SOLUTION: The coated granular material containing urea compound and triamide phosphate precisely controlled in elution from both the material, and the method of cultivation using the coated granular material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to coated granules and a method for cultivating crops using the same.

[0002]

2. Description of the Related Art Coated urea in which the surface of urea particles is coated with a coating material containing a resin has a slower effect than urea not coated with a coating material because the coating suppresses dissolution and elution of urea. Yes, excellent in control of dissolution. For this reason, in the agricultural field, the coated urea is used for the purpose of labor saving of topdressing work and reduction of environmental pollution by fertilizer.

[0003]

A fertilization method in which the coated urea is applied at the time of sowing or at the start of raising a seedling and the nitrogen component required by the plant is supplied by a single fertilization until harvesting has been attempted. Has been put to practical use. However, the plants during the seedling raising period are susceptible to inorganic nitrogen components, particularly ammonia nitrogen components, and the conventional coated urea may cause growth disorders depending on the application method and conditions. In order to avoid this problem, a timed elution type coated urea with a small initial elution amount has been developed, but if the suppression of the initial elution is incomplete, a problem may occur.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the problems involved in the above prior art. As a result, if the surface of the particles containing the urea-based compound and the phosphoric acid triamide is a coated granular material coated with a coating material containing a resin, it is possible to reduce the growth disturbance due to inorganic nitrogen during the seedling raising period. The present invention has been completed based on the findings.

The present invention has the following constitutions (1) to (7). (1) Coated granules in which the surfaces of particles containing a urea compound and phosphoric acid triamide are coated with a coating material containing a resin.

(2) The urea compound and the triamide phosphate during the period from the application of the coated granule to the time when the cumulative dissolution rate of the urea compound reaches 10% by weight of the total urea compound contained in the coated granule. Weight ratio (eluate of urea compound / eluate of phosphoric acid triamide) of 20 to 2000
2. The coated granular material according to the above item 1, wherein the range is 0.

(3) The first method, wherein the urea compound is urea.
Item 3. The coated granular material according to item 2 or 2.

(4) The coated granular material according to the above (1) or (2), wherein the phosphoric triamide is an N-alkylthiophosphoric triamide.

(5) The N-alkylthiophosphoric acid triamide is N- (n-butyl) thiophosphoric acid triamide.
Item 7. The coated granular material according to item 1.

(6) The coated granular material according to the above (1), wherein the resin is at least one selected from an olefin polymer, an olefin copolymer, a vinylidene chloride polymer, and a vinylidene chloride copolymer.

(7) The period (D1) until the cumulative dissolution rate of the urea-based compound reaches 10% by weight of the total urea-based compound contained in the coated granular material;
2. The coated granular material according to claim 1, wherein a ratio (D1 / D2) to a period (D2) until the temperature reaches a range of 0.2 to 2. 3.

(8) A method for cultivating a crop using the coated granular material according to any one of (1) to (7).

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Phosphoric triamide, which is an essential component of the present invention, is known as a substance having an urease inhibitory effect, and has an effect of delaying the decomposition of urea compounds in soil. Conventionally, many substances such as hydroquinone and ammonium thiosulfate have been known as urease inhibitors.However, even if particles containing these substances are coated with a resin or the like, the durability of the urease inhibitory effect is poor and practicality is poor. However, it cannot be said that it has a sufficient effect in terms of the above.

The phosphoric triamide contained in the coated granular material of the present invention is not particularly limited as long as it has a sufficient urease-inhibiting effect.
-Dimethylphosphoric triamide, N-isopropylphosphoric triamide, N, N-diethylphosphoric triamide, N-ethylphosphoric triamide, N- (n-butyl) phosphoric triamide,
N- (sec-butyl) phosphoric triamide, N- (n-dodecyl) phosphoric triamide, N- (n-octyl) phosphoric triamide, N- (n-butyl) thiophosphoric triamide,
N, N-diethylthiophosphoric triamide, N- (n-hexyl) thiophosphoric triamide, N- (sec-butyl) thiophosphoric triamide, N, N-diisopropylthiophosphoric triamide, N, N-di- (n-butyl) N-alkyl phosphoric triamides such as thiophosphoric triamide,

Alternatively, aliphatic phosphoric acid triamides containing a cyclic aliphatic functional group such as N, N-dialkylphosphoric acid triamide, N-cyclohexylphosphoric acid triamide, N-cyclohexyl-N-methylphosphoric acid triamide, N-cyclohexylthiophosphoric acid triamide; Aliphatic phosphoric acid triamide containing an aromatic functional group such as benzyl-N-methylphosphoric acid triamide, N-benzyl-N-methylthiophosphoric acid triamide, N-allylic phosphoric acid triamide, N- (diaminophosphinyl)
Examples thereof include piperidine, N- (diaminothiophosphinyl) piperidine, and N- (diaminothiophosphinyl) pyrrolidone. In the present invention, one or more of these phosphoric triamides may be arbitrarily selected and used.

In the present invention, among the phosphoric triamides, N-alkylthiophosphoric triamides are preferred in terms of urease inhibitory effect, and among them, N- (n-butyl) thiophosphoric triamide is particularly effective. It can be preferably used.

In the coated granular material of the present invention, the weight ratio of the elution amount of the urea compound and the phosphoric acid triamide (the amount of the urea compound eluted / the amount of the phosphoric acid triamide eluted) is determined after the application of the coated granular material. Is preferably in the range of 20 to 20,000 in a period until the cumulative dissolution rate of the compound reaches 10% by weight of the total urea-based compound contained in the coated granular material. The coated granules having a weight ratio of less than 20 have too high a content of phosphoric acid triamide, are low in practicality in terms of production difficulty and cost, and if the weight ratio exceeds 20,000, the urease inhibitory effect is low.

The weight ratio is achieved by adjusting the composition of the particles to be coated as appropriate. In particular,
It can be achieved relatively easily by adjusting the ratio of the urea compound and the phosphoric triamide contained in the coated granules. The content ratio of the urea compound and the phosphoric triamide to the coated granules of the present invention is preferably in the range of 0.003 to 4% by weight, more preferably 0.01%, of the phosphoric triamide content based on the urea compound content. -1% by weight. The content ratio of phosphoric triamide is 0.00
When it is less than 3% by weight or more than 4% by weight, it is difficult to control the weight ratio to 20 to 20,000.

The urea-based compound essential for the present invention is not particularly limited, and may have any molecular structure such as linear, branched chain, and cyclic as long as it has a molecular structure decomposed by urease. May be one with. Specific examples include urea, urea-formaldehyde condensate, urea-acetaldehyde condensate, urea-isobutyraldehyde condensate, guanylurea, and furfural-urea condensate. In the present invention, one or more of them may be arbitrarily selected and used. In the present invention, among the urea-based compounds, urea can be preferably used in terms of raw material cost.

As a method for producing the coated granular material of the present invention, a method is effective in which particles containing a urea compound and phosphoric acid triamide are granulated, dried and coated with a resin-containing coating material. The particles may be composed only of a urea-based compound and phosphoric triamide, or may contain other components as needed. As other components, other fertilizer components, various granulation auxiliaries, binders, and the like can be used.

Other fertilizer components include ammonium sulfate, salt ammonium,
Nitrogen fertilizers such as ammonium nitrate, lime nitrogen, humic acid ammonia, nitrate lime, sodium nitrate, oxamide, etc., and kali fertilizers such as sulphate, chloride, carbonate, sulphate lime, bicarbonate, humic acid, silicic acid, etc. Phosphoric fertilizers such as phosphating fertilizers, processed phosphate fertilizers, by-produced phosphate fertilizers, organic fertilizers such as bone meal, oil cake and meat meal, ordinary chemical fertilizers, advanced chemical fertilizers, trace element fertilizers, calcareous fertilizers, and clay fertilizers And siliceous fertilizers.

Examples of granulation assistants include bentonite, clay, kaolin, sericite, talc, acid clay, pumice,
Mineral substances such as silica sand, silica stone, zeolite, perlite and vermiculite, and plant substances such as firgrass, sawdust, wood flour, pulp floc and soy flour can be mentioned. The granulation aid can be used particularly effectively when it is desired to increase the content of phosphoric triamide in the particles.

As the binder, gum arabic, sodium alginate, glycerin, gelatin, molasses, microcrystalline cellulose, pitch, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, alumina sol, cement, polyphosphoric acid sodium,
Examples include lignin sulfonate, polyvinyl alcohol, polyethylene glycol, surfactant, starch, liquid paraffin, and thermosetting resin raw materials.

The method for granulating the particles is not particularly limited, but the granulation method includes rolling granulation, compression granulation, stirring granulation, extrusion granulation, and crushing granulation. Granulation method, fluidized bed and fluidized bed multifunctional granulation method, spray drying granulation method, vacuum freeze granulation method, submerged granulation method and the like can be mentioned. Since some phosphoric triamides have low resistance to high temperatures, it is preferable to granulate the raw materials so as not to be exposed to high temperatures.

When producing particles containing N-alkylthiophosphoric acid triamide, the substance alone has problems in storage stability, stability during production, and simplicity of production. It is preferable to use it after dissolving it in a glycol-based solvent containing a nonionic surfactant such as an alkylphenyl polyether alcohol and N-alkyl-2-pyrrolidone as an auxiliary solvent. If the solution obtained by this is used, it can be produced by impregnating the particles with particles containing a urea-based compound.

As a method for impregnating the particles containing the urea compound with the solution, a method in which the particles are fluidized by using a rotating dish-type pan or a drum-type rolling layer, and the solution is directly sprayed, And a method of immersing the particles in the solution, and the method can be selected according to the situation.

The particles containing the urea compound and the phosphoric acid triamide are dried after granulation, so that the coating operation and the storage after coating can be made easier. The drying method is not particularly limited, a hot air drying method,
Through-air drying, spray drying, flash drying, infrared drying,
High frequency drying, freeze drying, etc. can be used,
Since some phosphoric triamides have low heat resistance, it is desirable to dry while keeping the temperature of the grain surface or inside as low as possible.

The resin used for the coating material for coating the particles is not particularly limited, and examples thereof include a thermoplastic resin, a thermosetting resin, and an emulsion. Specific examples of the thermoplastic resin include olefin-based polymers, vinylidene chloride-based polymers, diene-based polymers, waxes, polyesters, petroleum resins, natural resins, oils and fats and modified products thereof, and urethane resins.

As the olefin polymer, polyethylene, polypropylene, ethylene-propylene copolymer,
Ethylene-carbon monoxide copolymer, ethylene-hexene copolymer, ethylene-butadiene copolymer, polybutene,
Butene-ethylene copolymer, butene-propylene copolymer, polystyrene, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-
An acrylic acid copolymer and an ethylene-methacrylic acid ester copolymer can be exemplified. As the vinylidene chloride-based polymer, a vinylidene chloride-vinyl chloride copolymer can be exemplified.

Examples of the diene polymer include butadiene polymer, isoprene polymer, chloroprene polymer, butadiene-styrene copolymer, EPDM polymer, and styrene-isoprene copolymer.

Examples of waxes include beeswax, Kibo, paraffin, and the like. Polyesters include polylactic acid,
Aliphatic polyesters such as polycaprolactone and aromatic polyesters such as polyethylene terephthalate can be exemplified. Natural resins include natural rubber and rosin, and oils and fats and modified products thereof include cured products, solid fatty acids and metal salts. Can be exemplified.

As the thermosetting resin, a phenol resin,
Furan resin, xylene / formaldehyde resin, ketone formaldehyde resin, amino resin, alkyd resin, unsaturated polyester, epoxy resin, silicon resin, urethane resin, drying oil and the like can be mentioned. These thermosetting resins have many combinations of monomers, but in the present invention, types and combinations of monomers are not limited. Further, in addition to a polymer of monomers, a polymer of a dimer or a polymer, or a mixture thereof may be used. Further, a mixture of a plurality of different types of resins may be used.

As the phenol resin, phenol, o-
Phenols such as cresol, m-cresol, p-cresol, 2,4-xylenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, 2,6-xylenol, and 3,4-xylenol And those obtained by a condensation reaction of at least one selected from aldehydes with at least one selected from aldehydes represented by formaldehyde.

As typical furan resins, phenol / furfural resin, furfural / acetone resin,
And furfuryl alcohol resin. The xylene / formaldehyde resin is a condensation of at least one selected from xylenes such as o-xylene, m-xylene, p-xylene, and ethylbenzene with at least one selected from aldehydes represented by formaldehyde. Those obtained by the reaction can be used.

Examples of the ketone formaldehyde resin include acetone / formaldehyde resin, cyclohexanone / formaldehyde resin, acetophenone / formaldehyde resin, and higher aliphatic ketone / formaldehyde resin.

As the amino resin, a resin obtained by a condensation reaction of at least one amino group-containing monomer such as urea, melamine, thiourea, guanidine, dicyandiamide, guanamine, and aniline with formaldehyde is used. Can be mentioned.

The alkyd resin may be either non-inverted type or inverted type, and is selected from polyhydric alcohols such as glycerin, pentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, sorbitol, mannitol, and trimethylolpropane. Phthalic anhydride, isophthalic acid, maleic acid, fumaric acid, sebacic acid, adipic acid, citric acid, tartaric acid, malic acid, diphenic acid, 1,8-
Examples thereof include those obtained by condensing naphthalylic acid, terpene oil, rosin, and one or more polybasic acids such as unsaturated fatty acids and adducts of maleic acid.

The fatty oils or fatty acids used in modifying the alkyd resin include linseed oil, soybean oil,
Mention may be made of perilla oil, fish oil, tung oil, sunflower oil, walnut oil, deer oil, castor oil, dehydrated castor oil, distilled fatty acids, cottonseed oil, coconut oil, and their fatty acids, or monoglycerides transesterified with glycerin. In addition, resin modified products such as rosin, ester rosin, copal, and phenol resin can also be used.

As the unsaturated polyester, maleic anhydride, fumaric acid, itaconic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, 3,6-
Endomethylene tetrahydrophthalic anhydride, adipic acid, sebacic acid, tetrachlorophthalic anhydride, and 3,
One or more organic acids such as 6-endodichloromethylenetetrachlorophthalic acid and ethylene glycol;
Diethylene glycol, 1,2-propylene glycol, dipropylene glycol, hydrogenated bisphenolurea compound, 2,2-bis (4-oxyethoxyphenyl) propane,
And those obtained by a condensation reaction with at least one selected from polyols such as 2,2-bis (4-oxypropoxyphenyl) propane.

Further, for the purpose of accelerating the curing of the unsaturated polyester, styrene, vinyl toluene, diallyl phthalate, methyl methacrylate, triallyl cyanuric acid,
And those obtained by adding at least one kind selected from vinyl monomers such as triallyl phosphoric acid at the time of condensation can also be used.

Examples of the epoxy resin include bisphenol urea compound type, novolak type, bisphenol F type, tetrabisphenol urea type compound type, and diphenol acid type epoxy resin.

Further, it is also possible to use a composite resin such as a urethane-modified polyester resin.

Examples of the urethane resin include tolylene diisocyanate, 3,3′-bitrylene-4,4′-diisocyanate,
Diphenylmethane-4,4'-diisocyanate, polymethylene polyphenylene polyisocyanate, 3,3'-dimethyl-
Diphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate, triphenylmethane triisocyanate, 2,4-tolylene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xy At least one member selected from the group consisting of diisocyanates, dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, and diisocyanates such as naphthalene-1,5-diisocyanate, and polyoxypropylene polyols and polyoxyethylene polyols , Acrylonitrile-propylene oxide polymer, styrene-propylene oxide polymer,
Polyoxytetramethylene glycol, adipic acid-ethylene glycol, adipic acid-butylene glycol,
Adipic acid-trimethylolpropane, glycerin, polycaprolactone diol, polycarbonate diol, polybutadiene polyol, and one or more selected from polyols such as polyacrylate polyol, and those obtained by polyaddition polymerization. Can be.

When olefin polymers, olefin copolymers, vinylidene chloride polymers and vinylidene chloride copolymers are used, the elution of urea compounds and phosphoric acid triamide can be controlled more precisely. And is a particularly preferred coating material.

Examples of the coating material used in the present invention include fillers and surfactants for imparting hydrophilicity, in addition to the above-mentioned resins. Talc as a filler,
Clay, kaolin, bentonite, sulfur, muscovite, phlogopite, mica-like iron oxide, metal oxide, siliceous, glass, alkaline earth metal carbonate, sulfate, starch, etc. Examples of the agent include a nonionic surfactant represented by a fatty acid ester of a polyol. In the present invention, these coating materials may be used in combination so that a desired elution period or elution rate is obtained.

In the resin-containing coating material, the content of the resin is preferably in the range of 10 to 100% by weight, more preferably 20 to 100% by weight, based on the coating material.
% By weight. In the coating material containing an inorganic substance, the content ratio of the inorganic substance is 2% relative to the coating material.
It is preferably in the range of 0 to 100% by weight, and more preferably in the range of 50 to 90% by weight.

The coating ratio of the coating material in the coated granular material of the present invention is preferably in the range of 3 to 20% by weight, more preferably 5 to 12% by weight, based on the particles.

When the coated granular material of the present invention has a time-dissolving type urea compound release / release function, the amount of inorganic nitrogen supplied to the crop after application can be further reduced. It is particularly effective when applied.

In the present invention, the time-release type sustained release function refers to a period from application to water or soil until 10% by weight of all urea compounds contained in the coated granules are released (dissolution inhibition period). 80% by weight after releasing 10% by weight
The ratio (dissolution inhibition period / dissolution period) to the period until release (dissolution period) is in the range of 0.2 to 2.
Since the dissolution of the urea compound contained in the coated granules depends on the temperature of the applied water or soil, the above-mentioned ratio (dissolution inhibition period / dissolution period) is measured under a constant temperature condition. When the ratio is in the range of 0.2 to 2, it has a timed dissolution function that is effective even at a temperature under general cultivation conditions.

In order to achieve a long-term sustained release function and a timed elution-type sustained release function, the surfaces of the particles are completely covered with a resin having low moisture permeability, and the permeation of water can be suppressed to a very small extent. It is necessary to form a coating. That is, it is important to form a film without pinholes or cracks. In addition, by dispersing a saccharide polymer such as starch and its derivative in the coating film, the induction period until the start of elution and the duration of the elution after the start of the elution can be controlled, and a timed elution type release function is achieved. It is effective as a means.

Specifically, for example, Japanese Patent Application Laid-Open No. 6-87684
No. 4,019,098, a coating in which a saccharide polymer is dispersed in a resin, a first layer comprising an alkali substance and a mixture of an olefin polymer and an alkali water-soluble polymer disclosed in JP-A-4-202078. Coating composed of a second layer, a coating composed of a first layer composed of a highly water-swellable substance and a second layer composed of an olefin-based resin disclosed in JP-A-4-202079, JP-A-9-30883 And a film composed of a first layer containing a wax and a second layer containing a thermoplastic resin. Among them, JP-A-6-87684
With the composition disclosed in the coating disclosed in No. 5, since the timed elution function can be achieved with a single-layer coating, it is effective in terms of manufacturing cost, and is also advantageous in terms of the precision of the elution suppression period control. .

In the present invention, the coating with the coating material may be achieved by any method, specifically, a method of spraying a molten coating material onto the surface of the particles, a coating in which the coating material is dissolved in a solvent. A method of spraying a solution of the material on the surface of the particles, a method of adhering a powder of the coating material to the surface of the particles and then melting, a method of spraying the monomer on the surface of the particles and reacting on the surface of the granular material to form a resin (film formation) ), And a dipping method in which the particles are immersed in a coating material melt or a coating material solution.

As described above, many phosphoric triamides have low heat resistance. For this reason, it is necessary to coat the particles with a resin-containing coating material so that the surface and the inside of the particles are as low as possible or to select a method in which the exposure time to the high temperature is short. As a method for satisfying this condition, a method of forming a coating by applying a coating material dissolving solution dissolved in a solvent capable of dissolving the resin in the coating material to the particle surface by spraying (hereinafter referred to as “solution spraying method”) Can be mentioned).

When the filler is dispersed in the resin-containing coating material, it is important that the filler is uniformly dispersed in the coating in order to control the elution of the urea compound and the phosphoric triamide in a satisfactory manner. . In order to obtain a film in which the filler is uniformly dispersed, it is preferable to produce the coated granules by a solution spraying method.

An example of a coating apparatus that can be used in the solution spraying method will be described with reference to a jet apparatus shown in FIG. In this method, in order to uniformly disperse a coating material insoluble in a solvent such as an inorganic filler in a coating material dissolving liquid, it is necessary to particularly strongly agitate the coating material dissolving liquid. This jet device is used for the granular material 5 in a jet state.
The coating material solution is transported from the dissolution tank 11 and the spray nozzle 4
At the same time as spraying onto the surface of the particles 5 to coat the surface of the particles 5, a high-temperature gas flows into the jet tower 1 from below, and the coating material adhered to the particle surfaces by the high-speed hot air flow. The solvent in the solution is evaporated and dried instantaneously. The spraying time varies depending on the resin concentration of the coating material solution, the spray rate of the solution, the coverage, and the like, and these should be appropriately selected according to the purpose.

As a coating apparatus other than the jet apparatus illustrated in FIG. 1 that can be used in the present invention, a fluidized bed type or spouted bed type coating apparatus is disclosed in Japanese Patent Publication No. 42-24281 and Japanese Patent Publication No. 42-24282. And an apparatus for forming a fountain-type fluidized bed of particles with a gaseous substance and spraying a coating agent on a particle dispersion layer formed at the center of the apparatus. Examples of a rotary-type coating apparatus include JP-A-7-31914.
Publication No. 7-195007 and Japanese Patent Application Laid-Open No. 7-195007 discloses a method in which a granular material is transferred upward by a lifter provided on the inner periphery of the drum by rotation of the drum and then dropped, and a coating agent is applied to the surface of the falling granular material. And an apparatus for forming a film.

When the coated granules are obtained by a solution spraying method,
The solvent to be used is not particularly limited, but since the solubility characteristics for each solvent differ depending on the type of resin used for the film, the solvent may be selected in accordance with the resin used. For example, when using an olefin polymer, an olefin copolymer, a vinylidene chloride polymer, a vinylidene chloride copolymer as a resin, a chlorine-based solvent or a hydrocarbon-based solvent is preferable, and among them, tetrachloroethylene, trichloroethylene, and toluene are used. It is a particularly preferable solvent since a dense and uniform coating can be obtained when it is present.

The crop cultivation method of the present invention is not particularly limited as long as it is a cultivation method using the coated granular material of the present invention, such as a target crop, a fertilization method, and other cultivation conditions. When cultivating a crop, the method may be applied directly to the soil, or a method in which the coated granular material of the present invention is added as one of the compositions for cultivating seedlings.

The application rate is not particularly limited, and can be appropriately determined depending on the crop.

The time of application is not limited, either.
It may be applied to a seedling container such as a seedling raising box or a seedling pot at the start of seedling raising, or may be put into a fixed planting hole at the same time as transplanting a seedling, or may be sprayed on the surface of a cultivated soil when seeding in a field. . In the method for cultivating a crop according to the present invention, the seedlings are grown until the cumulative leaching rate of the urea compound reaches 10% by weight of the total urea compound contained in the coated granule after application of the coated granule to be used. It is preferable to use a coated granular material having a controlled elution suppression period since growth disorders can be further reduced. Upon application, they may be used in combination with agricultural materials such as agricultural chemicals as long as the effects of the present invention are not impaired.

The cultivation method of the present invention is not limited to crops, and can be used for field crops such as food crops, feed crops, and industrial crops, and horticultural crops such as fruit trees, vegetables and flowers. For example, food crops include rice, barley, corn, potatoes, legumes, feed crops include grasses, legumes, root crops for feed, and craft crops include taste crops (Tea, etc.), spice crops (pepper, etc.), oil crops (sesame, etc.), sugar crops (sugar beet, etc.), and fiber crops (cotton, etc.). Examples include drupes (peaches and the like), citrus fruits, and tropical fruit trees (pineapples and the like).
Vegetables include leafy vegetables, root vegetables, and fruit vegetables, and flowers include annual grasses, biannual grasses, prairie grasses, flowering trees, and the like. According to the cultivation method using the coated granular material of the present invention, growth disorders due to inorganic nitrogen during the seedling raising period can be reduced.

[0062]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In the following examples, “%” is “% by weight” unless otherwise specified. 1. Production of Particles Containing Urea Compound and Phosphoric Triamide (Particles A to F) Production of Urea-Containing Granules Urea was charged into a heatable vessel and heated and melted at 130 ° C. (urea melt). Clay was added to the melt so as to have a composition weight ratio shown in Table 1, and the melt was heated from a height of 20 cm to 50 ° C. while stirring, and a depth of 20 cm 5 L was added.
Was dropped from a glass tube equipped with a cock having a diameter of 2 mm to a liquid paraffin in a stainless steel container while adjusting the flow rate so that the particle diameter became about 2 mm, to obtain a granular urea-containing substance. Next, the granules were washed with hexane, dried and sieved to select particles having a particle size of 2 to 2.5 mm to obtain urea-containing granules.

Impregnation of N- (n-butyl) thiophosphoric triamide (hereinafter referred to as “NBPT”) For impregnation of NBPT, NBPT solution (AGROTAIN manufactured by IMC-Agrico; NBPT concentration 2)
5%), a 10-fold diluted solution of the NBPT solution (hereinafter referred to as “10-fold diluted solution”), and a 10-fold diluted solution of the NBPT solution.
A 0-fold diluted solution (hereinafter referred to as "100-fold diluted solution") was used. 1 kg of the urea-containing granules are placed in a sugar coating machine having a diameter of 45 cm, and the urea-containing granules are rolled at a rotation speed of 30 rpm while the N is adjusted to the particle composition shown in Table 1.
The BPT solution or the NBPT diluent was sprayed onto the urea-containing granules to obtain particles to be coated. The spraying was performed while blowing air at room temperature onto the granules so that the granules did not solidify. After the spray treatment, drying was performed for 24 hours at 35 ° C. using a fluidized drier.

[0064]

[Table 1] Urea: Special grade clay manufactured by Wako Pure Chemical Industries, Ltd. Clay: Kaolin clay No. manufactured by Takehara Chemical Industries Five

2. Production of coated granules (Production of Examples 1 to 8 and Comparative Examples 1 and 2) Each of particles A to F obtained in “1. Production of particles containing urea-based compound and phosphoric acid triamide” is coated. A method for performing the operation will be described. FIG. 1 shows the coating apparatus used. Into the jet tower 1 having a tower diameter of 250 mm, a height of 2000 mm, an air outlet diameter of 50 mm, and a cone angle of 50 degrees,
High-temperature hot air flowed in from the bottom toward the top. The high-temperature hot air is blown from a blower 10, passes through an orifice flow meter 9, is heated to a high temperature by a heat exchanger 8, flows into a jet tower 1, and is discharged from an exhaust gas outlet 3 installed at an upper part of the jet tower 1. You. 10 kg of particles were introduced into the jet tower 1 in which the high-temperature hot air was circulating from the inlet 2 provided on the side surface of the jet tower 1, and the particles 5 were caused to flow as shown in FIG. The hot air temperature was adjusted while measuring the hot air temperature at T1, the granule temperature at T2, and the exhaust temperature at T3.

In this embodiment, the flow rate (orifice flow meter 9) is 4 m ³ / min, and the hot air temperature (hot air temperature T1) 8
The test was performed at 0 ° C. ± 2 ° C. and a particle temperature (particle temperature T2) of 60 ± 2 ° C. On the other hand, the coating material having the composition shown in Table 2 is put into the dissolution tank 11, and the resin is dissolved by mixing and stirring at 100 ° C ± 2 ° C. Obtained.

The dissolving tank 11 was constantly stirred until the coating was completed. The coating material dissolving liquid 12 is supplied by a pump 6 to a spray nozzle 4 which is a 0.8-mm full-con type one-fluid nozzle installed at the lower part of the jet tower 1 at a flow rate of 50 g / m.
It was transported in, and sprayed and sprayed on the flowing particles 5. At this time, the dissolving tank 11 and a pipe from the dissolving tank 11 to the spray nozzle 4 have a double structure so that the temperature of the coating material dissolving liquid 12 does not become 80 ° C. or lower. The material solution 12 was transported while being heated.

The above-described coating operation is started when the particle temperature T2 of the flowing particles 5 reaches 60 ° C., and after the coating is sprayed for a predetermined time until the coating becomes 12% by weight of the coated particles, the coating operation is started. Note that the particles are maintained at 60 ° C. ± 2 ° C., and drying is performed by blowing only hot air for 10 minutes while controlling the temperature of the hot air. When the drying is completed, the blower 10
Was stopped, and the particles 5 were discharged from the outlet 7 at the lowermost part of the jet tower 1 to obtain Examples 1 to 8 and Comparative Examples 1 to 3 shown in Table 2.

3. Dissolution confirmation test of urea and NBPT 10 g of the coated granular material obtained above was
l) and allowed to stand at 25 ° C. After a predetermined period of time, the coated particulate matter and water are separated, and urea and N
The amount of BPT was determined by quantitative analysis. Urea was determined by the dimethylaminobenzaldehyde method described in the Fertilizer Analysis Method (P60-62, published by Yokendo Co., Ltd.), and NBPT was determined by high performance liquid chromatography. 200 ml of water is newly added to the coated granules separated from water and left at 25 ° C. again, and after a lapse of a predetermined period of time, the coated granules are separated from water after a predetermined period to quantitatively analyze the amount of eluted components. Was repeated. By repeating this operation, the relationship between the amount (cumulative amount) of both substances eluted in water and the number of days was graphed to prepare an elution rate curve. From this dissolution rate curve, the weight ratio of the dissolution amount of urea and NBPT (urea dissolution amount / NBPT) during the period from the application until the cumulative dissolution rate of urea reaches 10% by weight of the total urea contained in the coated granules.
Elution amount; hereinafter referred to as “A value”), a period (D1) until the cumulative urea elution rate reaches 10% by weight of the total urea contained in the coated granules, and 80% by weight exceeding 10% by weight. (D1 / D2) to the period (D2) until the time reaches
Value). Table 2 shows the results.

[0070]

[Table 2] PE: polyethylene (low density polyethylene d = 0.918)
[g / cm ³ ] (density JIS K6760), MI = 22 [g / 10m
in] (Melt Index JIS K6760)) EVA: Ethylene / vinyl acetate copolymer Vac = 45wt%
MI = 20 [g / 10min] Talc: Average particle size 10μm Flour: Soft flour 200mesh pass SA: Surfactant Polyoxyethylene nonyl phenyl ether

4. Measurement test of supply amount of inorganic nitrogen into soil 1 kg of air-dried soil (black and white soil, uncultivated soil) passed through a 2 mm sieve was placed in a 2 L container, and Examples 1 to 8,
1.0 g of each of the coated granules of Comparative Examples 1 and 2 in total nitrogen
A considerable amount of water was added to and mixed with 60% of the maximum water capacity to prepare a test soil sample. Cover the upper edge of the container containing the test soil sample with a polyethylene film.
It was left still in a thermostat at 0 ° C. After 10 days, all the soil was collected and mixed well, and then 10 g was collected. The amount of inorganic nitrogen in the collected soil is determined as ammonia, nitrite,
It was measured by the simultaneous leaching measurement method of nitrate nitrogen (the method described in Yokendo Soil Nutrient Measurement Method p197-p200). All tests were performed in a three-repeat system. In order to measure the amount of inorganic nitrogen originally contained in the test soil, a test section to which the granular material was not applied was also provided. By repeating such an operation, the amount of inorganic nitrogen supplied to 1 kg of the test soil by the 20th day was determined and is shown in Table 3.

From the results shown in Table 3, it was confirmed that the use of the coated granular material of the present invention can reduce the amount of inorganic nitrogen supplied to soil after application. The weight ratio of the amount of urea compound and phosphoric acid triamide eluted (the amount of urea compound eluted / the amount of phosphoric acid triamide eluted) is such that the cumulative amount of urea compound eluted after application of the coated granular material is contained in the coated granular material. In the period until reaching 10% by weight of all urea compounds, 20 to 2
It was recognized that when the content was in the range of 0000, the amount of inorganic nitrogen could be further reduced. Further, a period (D1) until the cumulative dissolution rate of the urea compound reaches 10% by weight of the total urea compound contained in the coated granular material, and a period until the cumulative dissolution rate exceeds 10% by weight and reaches 80% by weight. (D2) and the ratio (D1 /
When D2) was 0.2 to 2, it was recognized that the reduction was more effective in reducing the amount of inorganic nitrogen supplied after application.

5. Cultivation Test Tomato seedlings were grown using the coated granules of Examples 1 to 8 and Comparative Examples 1 and 2. Cultivation was performed in a nursery house in Yude, Minamata City, Kumamoto Prefecture. First, the Andosol and the coated granular material of the present invention were mixed and placed in a nursery box. After sufficient watering, the seeds were seeded (variety House Momotaro). The application rate of the coated granules was 12 kg of nitrogen (N) in terms of 10a. 15 after sowing
Table 3 shows the presence or absence of growth disorders after days.

Cultivation tests confirmed that the use of the coated granules of the present invention hardly caused growth disorders.

[0075]

[Table 3]

[0076]

According to the conventional total fertilizer application method, even when a time-eluting type of coated fertilizer is used, the growth of the seedlings is impaired by the fertilizer component, but the urea compound and the triamide phosphate are contained. However, the coated granular material of the present invention in which the elution of both substances is precisely controlled can reduce the growth disturbance of the seedling.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spouted bed.

[Explanation of symbols]

 1. Spout tower 2. 2. Granule inlet Exhaust gas outlet 4. Spray nozzle 5. Particles 6. Pump 7. Outlet 8. Heat exchanger 9. Orifice flow meter 10. Blower 11. Dissolution tank 12. Mixed solution of coating material T1. Hot air thermometer T2. Granular thermometer T3. Exhaust thermometer SL. steam

Claims (8)

[Claims] 1. A coated granular material in which the surface of a particle containing a urea compound and phosphoric acid triamide is coated with a coating material containing a resin. 2. A method according to claim 1, wherein the urea compound and the phosphoric acid triamide are used after the application of the coated granule until the cumulative leaching rate of the urea compound reaches 10% by weight of the total urea compound contained in the coated granule. 2. The coated granular material according to claim 1, wherein the weight ratio of the amount of eluted (the amount of urea-based compound eluted / the amount of phosphate triamide eluted) is in the range of 20 to 20,000. 3. The coated granular material according to claim 1, wherein the urea compound is urea. 4. The coated granular material according to claim 1, wherein the phosphoric acid triamide is an N-alkylthiophosphoric acid triamide. 5. The method according to claim 5, wherein the N-alkylthiophosphoric acid triamide is N-
The coated granule according to claim 4, which is (n-butyl) thiophosphoric triamide. 6. The coated granular material according to claim 1, wherein the resin is at least one selected from an olefin polymer, an olefin copolymer, a vinylidene chloride polymer, and a vinylidene chloride copolymer. 7. A period (D1) until the cumulative dissolution rate of the urea-based compound reaches 10% by weight of the total urea-based compound contained in the coated granules, and a time period exceeding 10% by weight and reaching 80% by weight. Ratio (D1 / D2) to the period (D2) is 0.2
The coated granular material according to claim 1, wherein 8. A method for cultivating a crop using the coated granular material according to any one of claims 1 to 7.