JP2019088262A - Raising method of paddy seed rice - Google Patents

Abstract

To provide a raising method of paddy seed rice having a small individual difference of a germination timing after disseminating coated rice paddy on a field, and capable of reducing a load of a rice producer after dissemination on the field.SOLUTION: A raising method of seedling has a coating step for forming coated rice paddy by forming a coating layer containing powder of iron oxide and a resin on the surface of rice paddy, and a dissemination step for disseminating the coated rice paddy on a field. The iron oxide may contain limonite. In the coated rice paddy, a germination rate when being immersed into water of 25°C for 50 hours is 0%, and the germination rate when being immersed for 90 hours is 90% or higher.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a method for raising a rice seed meal by directly sowing the rice seed meal in a rice field.

In recent years, in order to realize cost reduction and labor saving of rice cultivation, a direct sowing culture method of directly sowing a rice seed meal on a field in a flooded state has attracted attention.
As a direct seeding culture method, there is an iron coating technology which raises specific gravity so that the seed meal sown in the rice field does not float in the water of the rice field.
For example, Patent Document 1 describes a method for producing an iron powder-coated rice seed which is granulated by adding iron powder, calcium sulfate and / or a hydrate thereof, and water to rice seed.

In addition, Patent Document 2 describes a method for producing a propagation material coating in which a coating layer containing polyvinyl alcohol, a functional material, and a liquid is formed on the surface of a plant propagation material. Patent Document 2 describes iron oxide and reduced iron as functional materials.
Patent Document 3 describes an iron oxide coated seed in which the seed surface is coated with a mixture of iron oxide powder and alkaline earth metal carbonate. Patent Document 3, as the iron _{oxide, Fe 2 O 3, Fe 3} O 4, Fe 2 O 3 · H 2 O is described.

As a direct sowing culture method for sowing a coated rice seed meal, there is a method using a seedling raising method shown below.
First, the dried mackerel obtained by drying after threshing is activated by soaking treatment until the integrated temperature (average water temperature x immersion number of days) becomes about 60 (° C · day), and the dormancy of the seed pod is destroyed (dipping step) . As the soaking treatment, for example, a treatment of soaking dry soya in water having a water temperature of 15 ° C. for 4 days is performed. Thereafter, an iron-containing coating layer is formed on the surface of the seed meal after the seeding step to form a coated rice seed meal (iron coating step). Thereafter, the coated rice seed meal is sown in a field in a flooded state (seeding step).

Patent No. 4441645 JP, 2013-146266, A JP, 2016-189735, A

  In general, rice producers are working on direct sowing methods in parallel with transplanting methods. When the transplanting cultivation method and the direct sowing cultivation method are carried out in parallel, the soaking step and the iron coating step for producing the coated rice seed meal are carried out before the busy period of work in the transplantation cultivation method. Therefore, the coated rice seed meal produced is usually stored in a dry atmosphere for several weeks to 2 months from production to sowing.

  Drying of the coated rice seed meal during storage proceeds to the inside of the coating layer. As a result, some or all of the coated paddy rice seeds activated (damp-disrupted) by the seeding step fall into the dormant state (re-dormant state) again. In addition, there are individual differences in the degree of re-sleeping state in the coated paddy rice straw after storage due to the difference in storage period and storage conditions. As a result, when the covered paddy rice seeds after storage are sown in the field, individual differences in germination timing are large, individual differences in growth within the field of one stroke become large, and there is a disadvantage that cultivation management is difficult.

  In order to solve this problem, it is conceivable to perform a soaking treatment on the coated paddy rice straw before the sowing step to activate the coated paddy rice straw. However, when the soaking treatment is performed on the coated rice seed meal, the components forming the coating layer may be eluted or the coating layer may be disintegrated, and the function of the coating layer of increasing the weight of the seed meal may be lost. In addition, when the soaking treatment of the coated rice seeds is carried out in close contact with each other, re-aggregation of the coated rice seeds is caused, and the adaptability to the seeding machine is significantly impaired.

  In addition, even if the coated rice seed meal obtained by performing the iron coating step immediately after the seeding step is sown in the field immediately after production, there are individual differences in the degree of activation by the seeding step, so germination timing Individual differences could not be reduced sufficiently.

  The present invention has been made in view of the above circumstances, and it is possible to reduce the burden on paddy rice producers after seeding sown in the field with small individual differences in germination timing after sowing the coated paddy seed in the field. The task is to provide a method for raising seedlings.

[1] A coating step of forming a coating layer containing powder of iron oxide and a resin on the surface of the dry rice bran, and forming a coated rice seed meal,
And a seeding process for seeding the coated rice seed meal in a field.

[2] The method of raising a rice seed meal according to [1], wherein the iron oxide comprises limonite.
[3] One type selected from the group consisting of vinyl acetate polymer resin, acrylic acid ester copolymer resin, ethylene / vinyl acetate / acrylic acid copolymer resin, and ethylene / vinyl acetate copolymer resin The method for raising seedlings of a rice seed meal according to [1] or [2], including the above.
[4] The coated rice seed meal has a germination rate of 0% when immersed in water at 25 ° C. for 50 hours, and a germination rate of 90% or more when immersed in water for 90 hours [1]-[3] A method for raising seedlings of rice seed meal according to any of the above.

  The method for raising seedlings of paddy rice bran according to the present invention forms a coating layer containing powder of iron oxide and a resin on the surface of dried rice bran that has not been subjected to a seeding step to form a coated rice seed meal with a coating step and seeding step. And a seeding step of seeding the coated rice seed meal on the field without conducting the seeding treatment, which is a seedling raising method without performing the seeding treatment. For this reason, the individual difference in the sprouting timing in the sown | coated covered rice seed rice seed | species can be small, and the individual difference in the growth resulting from the individual difference in a germination timing can be suppressed. As a result, cultivation management after sowing to a field becomes easy, and the burden of a rice producer can be reduced.

Further, in the method of raising seedling seedling of the present invention, there is no covered seedling that germinates in a short period of time after sowing because the step of soaking is not performed. Therefore, it is possible to reduce the burden on the rice producer during the period from sowing to the start of germination of the coated rice seed meal.
Moreover, in the method for raising seedlings of rice seed meal according to the present embodiment, since the seeding step is not performed, it takes less time and effort to perform the seeding step as compared with the case where the seeding step is performed.
Further, in the method for raising seedlings of rice seed meal according to the present invention, since the soaking step is not performed, there is no individual difference in the degree of activation and re-sleeping state depending on the storage period and storage conditions of the coated rice seed meal. Therefore, the storage period and storage conditions of the coated rice seed meal can be freely determined according to the working efficiency of the rice producer.

It is the graph which showed the relationship of the elapsed time (immersion time) and the germination rate from the cultivation start about the covering rice seed rice seed | species of Example 1 and Comparative Example 1.

In order to solve the above-mentioned subject, the present inventor repeated earnest research as shown below.
Conventionally, when raising rice seedlings, the soaking process is carried out in which the dry rice obtained by drying after threshing is subjected to a soaking treatment to activate the rice seed meal. It is common knowledge of rice producers to perform the soaking treatment, and the soaking process has been considered to be an essential step to promote germination of rice seed meal.
However, as a result of the present inventor's examining the function of the seeding process in the seedling raising method containing an iron coating process, findings of (1)-(4) shown below were obtained.

(1) The germination rate is the same even in the case of the coated rice seed straw in which the seeding step was performed before the iron coating step, and in the coated rice seed rod in which the seeding step was not performed.
(2) Whether a coated rice seed meal that has undergone a seeding step before the iron coating step or a covered rice seed row that has not undergone a seeding step sowing the coated rice seed meal in the field until the germination rate reaches 100% Are equivalent.

(3) By performing the seeding step prior to the iron coating step, the period from seeding the coated rice seed row to the field to germination is shortened for some of the coated rice seed rows of the sown coated rice seed row . However, there are some coated rice seeds that do not show the effect of shortening the above period. This is presumed to be due to the fact that the difference in the degree of activation and / or re-dormant state of the sown-covered coated rice seeds is large.

(4) In the case of a coated rice cultivar not subjected to a soaking step before the iron coating step, there are no individuals that germinate in a short time after sowing. However, the time until the germination rate reaches 100% after sowing the coated rice seeds into the field is equivalent to that of the coated rice seeds obtained by the seeding step prior to the iron coating step. For this reason, the time difference (difference in the germination timing) between the individual who germinated first and the individual who germinated last among the sown covered paddy rice seeds is small compared with the coated paddy rice seed which performed the soaking step. This is presumed to be due to the fact that there is no individual difference in the degree of activation and re-dormant state in the coated rice seed meal produced without the seeding step.

  As a result of the present inventors' investigation based on the above findings, in order to make individual differences in the germination timing smaller in sown covered rice paddy rice seeds so as to suppress individual differences in growth caused by individual differences in the germination timing, Having found that it would be better not to do it, the present invention was conceived.

Hereinafter, the method for raising seedlings of a rice seed meal according to the present invention will be described in detail. The present invention is not limited to only the embodiments shown below.
The method for raising seedlings of paddy rice bran according to the present embodiment forms a coating layer containing powder of iron oxide and resin on the surface of dry rice paddy rice, and coats the coated rice paddy rice straw with a coating step to make coated paddy rice seed meal. And a seeding step.
The dry rice in the present embodiment means dry rice which has not been subjected to the immersion treatment and obtained by drying after threshing.
The method for raising seedlings of paddy rice seed meal according to the present embodiment is a method for raising seedlings without performing the soaking treatment, and the soaking treatment is not performed before the coating step or between the coating step and the sowing step.

(Coating process)
In the coating step, a coating layer containing powder of iron oxide and a resin is formed on the surface of the dry rice seedling that has not been subjected to the seeding treatment, which has been obtained by drying after threshing, to form a coated rice seed meal.
As a coating process, the following method 1 or method 2 can be used, for example.

"Method 1"
A mixture of iron oxide powder (a) and a rice seed rice dung which has not been subjected to a seeding treatment is prepared, and the obtained mixture is mixed with a composition (i) containing a resin (b) and a dispersion medium. Thereafter, the dispersion medium of the composition (i) is dried to form a coating layer containing an iron oxide powder and a resin on the surface of the rice seed meal.

  Specifically, for example, the granulating pan of a tumbling granulator is loaded with iron oxide powder (a) and dry rice with no seeding treatment, and those granulating pans are rotated. Make a mixture. Then, while rotating the granulating pan, the mixture is sprayed with the composition (i) containing the resin (b) and the dispersion medium and mixed. In method 1, as a method of spraying composition (i), you may carry out manually using misting etc., and you may use machines, such as a mist spraying apparatus. Thereafter, the adhered mixture of composition (i) is dried to remove the dispersion medium of composition (i). In the method 1, as a method of drying the mixture to which the composition (i) is attached, a method of air-drying etc. can be used, and it is not particularly limited. Specifically, the mixture to which the composition (i) is attached is placed on a container such as a stainless vat, a vinyl sheet, a newspaper, newspaper, etc., and air-dried in an air atmosphere at room temperature for several hours to one day. Can be mentioned. In the method 1, by drying the mixture to which the composition (i) is attached, the dispersion medium and the like of the resin (b) contained in the composition (i) is evaporated, and a coating layer having high hardness is obtained.

The composition (i) used in the method 1 may contain, in addition to the resin (b) and the dispersion medium, if necessary, a fertilizer component (c), a thickener (d), a dispersant (e), an antifoam agent ( f) may contain one or more components of other additives. Other additives include, for example, herbicides, fungicides, pest repellents, pest repellents and the like.
When the composition (i) contains one or more of the above components in addition to the resin (b) and the dispersion medium, the resin (b) is mixed with one or more of the above components using any method. Thus, the composition (i) can be produced. When the composition (i) contains one or more of the above components in addition to the resin (b) and the dispersion medium, the order of addition and mixing method of the respective components used in producing the composition (i) are particularly It is not limited.

  The viscosity of the composition (i) used in the method 1 is preferably 1 to 5 mPa · s, more preferably 1 to 3 mPa · s, and still more preferably 1 to 1.5 mPa · s. It becomes composition (i) suitable for spraying and mixing as the viscosity of composition (i) is 1-5 mPa * s.

"Method 2"
A dry rice grain not subjected to a seeding treatment is mixed with a powder (a) of an iron oxide, a composition (ii) containing a resin (b) and a dispersion medium. Thereafter, the dispersion medium of the composition (ii) is dried to form a coating layer containing iron oxide powder and resin on the surface of the rice seed meal.

  Specifically, for example, a dry rice bran that has not been subjected to a soaking treatment is loaded in a granulating pan of a tumbling granulator, and the composition (ii) is added and mixed while rotating the granulating pan. Thereafter, the smeared rice seed meal of composition (ii) is dried to remove the dispersion medium of composition (ii). As the method of drying the smeared rice seed meal of the composition (ii) in the method 2, a method similar to the method of drying the adhered mixture of the composition (i) in the method 1 can be used, and the method is particularly limited I will not. In method 2, by drying the smeared rice seed meal of the composition (ii), the dispersion medium and the like contained in the composition (ii) are evaporated, and a coating layer with high hardness can be obtained.

  The composition (ii) used in the method 2 is a paste-like one having iron oxide powder (a) as a filler. The composition (ii) is a powder of iron oxide (a), a resin (b) and a dispersion medium, and optionally, a fertilizer component (c), a thickener (d) and a dispersant (e) , An antifoam agent (f), and one or more components of the above-mentioned other additives by mixing using any method.

  The order of addition and mixing method of each component used in producing the composition (ii) is not particularly limited. For example, a method may be used in which all the components are collectively mixed by stirring at one time to prepare a composition (ii). In addition, one or more components selected from components other than iron oxide powder (a) and resin (b) and iron oxide powder (a) are stirred and mixed to prepare a mill base, and The remaining components including the resin (b) may be added, and the mixture may be further stirred and mixed to prepare a composition (ii). There is no restriction | limiting in particular in the combination of the component in the case of producing a mill base, All the components should just be contained in the produced composition (ii). In the present embodiment, since the dispersibility of the resin (b) is improved and the production efficiency is improved, it is preferable to produce the composition (ii) using a method for producing a mill base.

  The viscosity of the composition (ii) used in the method 2 is preferably 5,000 to 30,000 mPa · s, more preferably 6,000 to 28,000 mPa · s, still more preferably 6,000 to It is 25,000 mPa · s. When the viscosity of the composition (ii) is 5,000 to 30,000 mPa · s, it is suitable for handling as a paste.

[Iron oxide powder (a)]
In this embodiment, as iron oxide which forms powder (a) of iron oxide used as a material of a covering layer, either or both of an oxide and iron hydroxide can be used. For example, as iron oxide, ferrous oxide (FeO), triiron tetraoxide (Fe ₃ O ₄ ), α-iron oxyhydroxide (α-FeOOH), γ-iron iron oxyhydroxide (γ-FeOOH), etc. And is preferably brown iron oxide.
Examples of the mineral containing brown iron oxide include wustite, magnetite (ferrite), goethite (gesite), pyrite (lepidocrocite), limonite (limonite). Limonite is a common name of iron oxide mineral, and mainly refers to an aggregate of one or both of goethite and pig iron. As iron oxide, brown iron oxide is preferable because it is close to the color of a field and therefore less susceptible to bird damage. Among them, limonite is preferable from the viewpoint of stability and production cost.

As limonite, the content ratio of goethite is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more. When the content of goethite is 20% by mass or more, it exhibits a brown color. The content of goethite contained in limonite can be analyzed, for example, by X-ray diffraction (XRD) under the conditions of X-ray source CuKα, output 45 kV-40 mA, and scanning area (2θ) 10 to 90 deg.
Limonite may use natural products mined from the mine as it is. The limonite may be subjected to processing such as crushing with a grinder such as a spike mill and classification with a sieve after a ripening period such as outdoor exposure after mining.

  As Limonite mines currently in operation in Japan, Ebara Mine (Shinanocho, Kamisuinai-gun, Nagano Prefecture) and Daiichi Aso Mine (Aso City, Kumamoto Prefecture) are known. Limonite mined by open pit mining from the ore deposit by Yoshida No. Co., Ltd., Daiichi Aso Mine from Kashihara Mine, and after a ripening period such as outdoor exposure for several years, grinding with a crusher such as spike mill And sells after processing such as classification with sieve. These commercially available limonite can be used as it is as brown iron oxide powder (a).

In the present embodiment, Fe ₂ O ₃ (iron oxide (III)), α-Fe ₂ O ₃ (α-iron oxide (III)), β, as long as the brown color of iron oxide powder (a) is not impaired. Iron oxides such as -Fe ₂ O ₃ (β-iron oxide (III), γ-Fe ₂ O ₃ (γ-iron oxide (III)), ε-Fe ₂ O ₃ (ε-iron oxide (III)) Powder, β-FeOOH (β-iron oxyhydroxide), δ-FeOOH (δ-iron oxyhydroxide), Fe (OH) ₂ (iron (II) hydroxide), Fe (OH) ₃ iron hydroxide (iron (II) hydroxide) Powders of iron hydroxide such as III) may be included.

In the present specification, brown is a color centered on L ^* : 38.21, a ^* : 40.54, b ^* : 51.83, which is represented by L ^* a ^* b ^* color system, L ^* and, in the case of fixing the ^{a * b *} is 30 to 200, ^{L *} and ^{b *} 30 to 50 if the fixed ^{a *} is a, the case of fixing ^{a *} and ^{b * L *} is 15 to 45 It is the color of the range.

  The particle size of the iron oxide powder (a) is preferably in the range of 30 to 100 μm, more preferably 30 to 80 μm, and still more preferably 30 to 75 μm. When the particle size is 30 μm or more, the volume of the coating layer required is small because the bulk specific gravity is large, and the working efficiency is improved. When the particle size is 100 μm or less, the coating layer collapses in water and is less likely to peel off the surface of the rice seed meal. The average particle size referred to here is volume cumulative particle size D50 measured by a laser diffraction scattering type particle size distribution measuring apparatus.

  The content of the iron oxide powder contained in the coating layer is preferably 10 to 50 parts by mass, more preferably 20 to 45 parts by mass, and still more preferably 25 parts by mass with respect to 100 parts by mass of the coated rice seeds. 40 parts by mass. When the content of the iron oxide powder contained in the coating layer is 10 parts by mass or more, the apparent specific gravity increases and it becomes difficult to flow after seeding. In addition, when the content of the iron oxide powder contained in the coating layer is 50 parts by mass or less, maintenance of the coating layer is facilitated.

  The content of iron oxide powder contained in the covering layer is preferably 70 to 99 parts by mass, more preferably 80 to 99 parts by mass, and still more preferably 90 to 99 parts by mass with respect to 100 parts by mass of the covering layer. It is 99 parts by mass. When the content of iron oxide powder contained in the coating layer is 70 parts by mass or more, floating of rice seed meal can be effectively prevented. In addition, when the content of the iron oxide powder contained in the coating layer is 99 parts by mass or less, the content of the resin (b) in the coating layer can be easily secured, and a coating layer having high strength can be obtained. It will be easier.

[Resin (b)]
Examples of the resin (b) used as the material of the covering layer include vinyl polymers, acrylic polymers, diene polymers, copolymers of vinyl monomers and at least two of acrylic monomers and diene monomers, urethane polymers, biodegradable polymers Etc. Specific examples thereof include vinyl acetate polymer resin, acrylic ester copolymer resin, ethylene / vinyl acetate / acrylic acid copolymer resin, ethylene / vinyl acetate copolymer resin and the like. These resins may be used alone or in combination of two or more.

  The dispersion medium is not particularly limited as long as it can disperse or dissolve the resin (b). As the dispersion medium, it is preferable to use water because the work environment and the health load of the workers are small.

[Organic solvent]
In the present embodiment, a composition (i) (see “method 1” described above) including the resin (b) when forming the coating layer (composition including the powder (a) of the iron oxide and the resin (b) When the compound (ii) (see “Method 2” described above) is used, an organic solvent can be included as a dispersion medium in the composition in any case.
As the organic solvent, it is preferable to use one miscible with water. Specifically, as an organic solvent, alcohols such as methanol, ethanol, normal propyl alcohol, isopropyl alcohol and the like can be used from the viewpoint of shortening the time for drying the dispersion medium in forming the coating layer and sterilization of the composition. It is preferred to use. Among these, it is more preferable to use ethanol from the viewpoint of environmental load.

  The content of the organic solvent is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less with respect to the entire dispersion medium contained in the composition. By setting the content of the organic solvent to 50 parts by mass or less, a composition having excellent workability and hygiene can be obtained with low environmental load.

As the resin (b), it is preferable to use a resin emulsion because a coated layer having a good coating strength can be obtained. In particular, an aqueous resin emulsion in which the dispersion medium is water can prevent deterioration of seeds due to the provision of the coating layer, and is preferable because the burden on the environment is small.
As the aqueous resin emulsion, vinyl acetate polymer aqueous emulsion, acrylic acid ester copolymer aqueous emulsion, ethylene / vinyl acetate / acrylic acid copolymer aqueous emulsion, ethylene / vinyl acetate copolymer aqueous emulsion, and biodegradable Resin emulsions are preferred. Among these, ethylene / vinyl acetate copolymer aqueous emulsion and biodegradable resin emulsion can be more preferably used from the viewpoint of environmental load.

As a product containing an aqueous resin emulsion, for example, Polysol (registered trademark) series (vinyl acetate polymer aqueous emulsion, acrylic ester copolymer aqueous emulsion, ethylene / vinyl acetate copolymer aqueous solution provided by Showa Denko KK) And ethylene-vinyl acetate-acrylic acid copolymer aqueous emulsion).
As a biodegradable resin emulsion, Randy PL series (polylactic acid resin emulsion) manufactured by Miyoshi Yushi Co., Ltd. can be mentioned.

A composition (i) containing a resin (b) and a dispersion medium is sprayed onto a mixture of dry rice and dry powder of iron oxide (a) which has not been subjected to a seeding treatment to form a coating layer (the method described above In the case of 1)), the solid content concentration of the resin emulsion used as the resin (b) is preferably 1 to 10% by mass because handling is easy, more preferably 2 to 7% by mass, and further preferably Is 3 to 6% by mass.
When a coating layer is formed using composition (ii) containing powder (a) of iron oxide, resin (b) and dispersion medium (see “Method 2” described above), resin (b) and dispersion medium are used. The solid content concentration of the resin emulsion to be contained is preferably 10 to 85% by mass because handling is easy, more preferably 25 to 70% by mass, and still more preferably 40 to 60% by mass.

  The content of the resin contained in the coating layer is preferably 0.1 to 43 parts by mass, more preferably 0.5 to 25 parts by mass, and further preferably 1 to 5 parts by mass with respect to 100 parts by mass of the iron oxide powder. It is 10 parts by mass. When the content of the resin contained in the coating layer is 0.1 parts by mass or more, a coating layer having excellent coating strength can be obtained. Moreover, workability | operativity at the time of forming a coating layer becomes favorable for content of resin contained in a coating layer to be 43 mass parts or less.

[Fertilizer component (c)]
The covering layer may contain a fertilizer component as needed. As a fertilizer component to be used as a material of the coating layer (c), for example, _KH 2 PO ₄ (potassium dihydrogen _phosphate), K 2 HPO ₄ (dipotassium hydrogen _phosphate), K 3 PO ₄ (phosphoric acid tripotassium ), Potassium phosphates such as K ₄ P ₂ O ₇ (tetrapotassium pyrophosphate), K ₅ P ₃ O ₁₀ (potassium tripolyphosphate), (KPO ₃ ) _n (potassium metaphosphate, n = 10,000) And MoO ₃ (molybdenum (VI) oxide), adenosine, guanosine, thymidine, cytidine, uridine, xanthosine, and inosine, and their 2'-deoxy forms, and examples of nucleotides include adenylate (adenosine-5 ' -Phosphate), guanylate (guanosine-5'-phosphate), thymidylate (thymidine-5'-phosphate), uridylate (uridine- 5'-phosphate), xanthic acid (xanthosine-5'-phosphate), and inic acid (inosine-5'-phosphate), and nucleosides such as these 2'-deoxy forms, nucleotides, uric acid and inosine Etc. Nucleosides and nucleotides may be in free form or may be salts such as sodium salt, potassium salt and the like. Among them, food additives (KPO ₃ ) _n (potassium metaphosphate, n = 10,000), MoO ₃ (molybdenum (VI) oxide), inosine, and inosinic acid (inosine-5′-phosphate) are preferable. One or more selected. These fertilizer components may be used alone or in combination.

  The content of the fertilizer component contained in the coating layer is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 7.5 parts by mass, and still more preferably 100 parts by mass of the iron oxide powder. 0.1 to 5 parts by mass. When the content of the fertilizer component contained in the coating layer is 0.01 parts by mass or more, the growth promoting effect is sufficiently obtained by the fertilizer component. It is favorable in terms of productivity and cost that the content of the fertilizer component contained in the coating layer is 10 parts by mass or less.

[Thickener (d)]
In the case of using the composition (i) containing the resin (b) (see “Method 1” described above) when forming the coating layer in the present embodiment, or the powder (a) of iron oxide and the resin (b) In any of the cases where the composition (ii) (see “Method 2” described above) is used, the composition may contain a thickener (d), and in particular, the composition (ii) It is preferable to contain d).
The inclusion of the thickener (d) in the composition (ii) used in forming the coating layer can prevent the iron oxide powder (a) from separating in the composition (ii) The composition (ii) is in a uniform state. As a result, a coating layer having a uniform composition is obtained.

  As thickener (d), cellulose based compounds such as hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose nanofibers, and glycols such as polyethylene glycol distearate, sodium polyacrylate, guar gum, xanthan gum, and the like A mixture of them can be illustrated. Among these, hydroxypropyl cellulose known as a food additive, guar gum, xanthan gum, and a mixture thereof and cellulose nanofibers can be preferably used as a thickener (d).

  The content of the thickener (d) in the composition (ii) containing the powder (a) of iron oxide and the resin (b) is 0 to 5 with respect to 100 parts by mass of the powder (a) of iron oxide It is preferable that it is a mass part, More preferably, it is 0-3 mass parts, More preferably, it is 0-1 mass part. When the content of the thickener (d) is 5 parts by mass or less, the composition (ii) containing the same has good handleability.

[Dispersing agent (e)]
In the case of using the composition (i) containing the resin (b) (see “Method 1” described above) when forming the coating layer in the present embodiment, or the powder (a) of iron oxide and the resin (b) In any of the cases where the composition (ii) (see “Method 2” described above) is used, the composition may contain the dispersant (e), and in particular, the composition (ii) may contain the dispersant (e) Is preferably contained.
By including the dispersant (e) in the composition (ii) used when forming the coating layer, the wetting of the surface of the iron oxide powder (a) in the composition (ii) is improved, The dispersibility of the iron oxide powder (a) is improved. Thus, a coated layer having a uniform composition is obtained.

  A surfactant can be used as the dispersant (e). As the surfactant, various known surfactants can be selected and used according to the surface state of the powder (a) of iron oxide to be used. Specifically, polycarboxylic acids such as Demol (registered trademark) EP, Homogen (registered trademark) L-18, Poise (registered trademark) 520, and 530 (above, manufactured by Kao Corporation) as anionic surfactants. Type surfactant, naphthalenesulfonic acid formalin condensate type surfactant such as Demol (registered trademark) N (manufactured by Kao Corporation), and the like. In addition, as nonionic surfactants, acetylene glycol type activators such as Surfynol (registered trademark) TG, 104E (all manufactured by Nisshin Chemical Industry Co., Ltd.), and Emulgen (registered trademark) 102KG, 103, Polyoxyethylene lauryl ether such as 104P, 105, 106, 108, 109P, 120, 123P, 130K, 147, 150 (above, manufactured by Kao Corporation), EMALGEN (registered trademark) ) Polyoxyethylene cetyl ether such as 210P and 220 (manufactured by Kao Corporation), and polyoxyethylene stearyl ether such as EMALGEN (registered trademark) 306P, 320P and 350 (manufactured by Kao Corporation) , Emargen (registered trademark) 404, 408, 409V, 420, 430 ( Above, such as polyoxyethylene oleyl ether such as Kao Co., Ltd.), Peginol (registered trademark) O-6A (manufactured by Toho Chemical Industry Co., Ltd.), Tirabazole (registered trademark) L-01 (manufactured by Taiyo Kagaku Co., Ltd.), etc. Fatty acid ester, polyoxyethylene alkyl ether surfactant such as Neugen (registered trademark) ET (made by Daiichi Kogyo Seiyaku Co., Ltd.), Nonal 210, 212 (made by Toho Chemical Industry Co., Ltd.), etc. Polyoxyethylene alkyl phenyl ether type surfactant etc. are mentioned. These surfactants may be used alone or in combination of two or more.

  The content of the dispersant (e) in the composition (ii) containing the powder (a) of iron oxide and the resin (b) is 0.01 to 100 parts by mass of the powder (a) of iron oxide The amount is preferably 30 parts by mass, more preferably 0.1 to 15 parts by mass, and still more preferably 1 to 10 parts by mass. When the content of the dispersant (e) is 0.01 parts by mass or more, the effect of improving the dispersibility of the iron oxide powder (a) can be sufficiently obtained. When the content of the dispersant (e) is 30 parts by mass or less, the influence on the disintegration property of the coating layer is small.

[Antifoam agent (f)]
In the case of using the composition (i) containing the resin (b) (see “Method 1” described above) when forming the coating layer in the present embodiment, or the powder (a) of iron oxide and the resin (b) In any of the cases where the composition (ii) (see “Method 2” described above) is used, the composition may contain an antifoam agent (f), and particularly in the composition (ii) It is preferable to contain f).
When the foam inhibitor (f) is contained in the composition (ii) used in forming the coating layer, the workability in forming the coating layer is improved.

  As an antifoam agent (f), Nopco (registered trademark) 8034, Nopco (registered trademark) 8034-L, SN deformer 477, SN deformer 5013, SN deformer 247, SN deformer 382 (trade name, manufactured by San Nopco Ltd.) , Anti-home 08 (trade name), Emargen (registered trademark) 903 (above, Kao Corporation), Awa Break G-109, the same SO-101, the same L-01, the same LJ-01, the same H-01 (more than Commercial products such as Taiyo Kagaku Co., Ltd.) can be used.

  The content of the foam inhibitor (f) in the composition (ii) containing the powder (a) of iron oxide and the resin (b) is 0.01 relative to 100 parts by mass of the powder (a) of iron oxide It is preferably 3 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 0.1 to 1 parts by mass. When the content of the antifoam agent (f) is 0.01 parts by mass or more, a good antifoaming effect can be obtained. In addition, when the content of the antifoam agent (f) is 3 parts by mass or less, the influence on the disintegration of the coating layer is small.

The hardness of the coating layer of the coated rice seed meal obtained by performing the coating step is preferably 50 to 200N. When the hardness of the coating layer is 50 N or more, bird damage is unlikely to occur. Moreover, a germination rate is favorable in the hardness of a coating layer being 200 N or less.
The hardness of the coating layer is a value measured for each of the seeds forming the coating layer (in other words, "in the state of the coated rice seed meal"). A hardness meter HH-411 manufactured by Mitutoyo Co., Ltd. can be used to measure the hardness of the coating layer.

  The coating ratio of the coated rice seed meal (the ratio of the weight of the coated layer of the coated rice seed meal to the dry weight (mass of the coating layer / weight of dry weight)) is preferably 0.1 to 0.7, and 0.3 It is more preferable that it is -0.6. When the coating ratio is 0.1 or more, the coated rice seed meal is sufficiently heavy, and the coated rice seed meal can be prevented from floating in the water of the rice field. If the coating ratio is 0.7 or less, the individual difference in the germination timing after sowing the coated rice seed meal in the field becomes smaller, which is preferable.

  The coated rice seed meal obtained by performing the coating step may be stored for any period of time before the sowing step, if necessary.

(Seeding process)
In the sowing step, the coated rice seed meal is sown in the field without soaking treatment. As a method of sowing a coated rice seed meal in a field, arbitrary methods, such as a method using a general sowing machine, can be used, and it is not particularly limited.

  In the method for raising seedlings of the rice seed meal according to the present embodiment, since the soaking treatment is not performed, the individual difference in the germination timing in the sown coated rice seed meal is small. Specifically, in the present embodiment, the coated rice seed meal seeded has a germination rate of 0% when immersed in water at 25 ° C. for 50 hours, and a germination rate of 90% or more when immersed in water for 90 hours Is preferred. When such a coated rice seed meal is sown, for example, in a paddy field having a water temperature of 25 ° C., individuals of 90% or more germinate within about 50 to 90 hours after sowing. Therefore, individual differences in growth due to individual differences in germination timing after sowing become very small. In addition, in such a coated rice seed meal, there is no coated rice seed meal that germinates in a short time after sowing. From these things, cultivation control after seeding and until germination of coated rice seed meal is started can be facilitated, and the burden on rice producers can be reduced more effectively.

  Hereinafter, the present invention will be more specifically described by way of examples and comparative examples. The present invention is not limited to the following examples.

Example 1
10 g of iron oxide powder shown in Table 1 and 20 g of dry rice bran (2016 Toyama Koshihikari) not impregnated with the seeds shown in Table 1 were loaded in the granulating pan of a tumbling granulator (made by As One Corp.) The granulating pan was rotated to prepare a mixture of rice seed meal and iron oxide powder. Next, as the composition (i) containing the resin (b) and water as a dispersion medium while rotating the granulating pan, the lonfix eco # 700 (manufactured by Showa Denko KK, solid content concentration 50) is an aqueous resin emulsion. % And a resin component (ethylene vinyl acetate copolymer) diluted 10-fold with ion-exchanged water were sprayed and mixed with 7.9 g (solid content: 0.395 g). Thereafter, the adhered mixture of the composition (i) was air-dried on a stainless steel vat overnight to remove the dispersion medium of the composition (i). According to the above steps, a coated rice seed meal of Example 1 having a coating layer containing an iron oxide powder and a resin on the surface of the rice seed meal and having a coating ratio shown in Table 1 was obtained.

As the limonite, iron (III) oxide (Fe ₂ O ₃ ), triiron trioxide (Fe ₃ O ₄ ) and iron shown in Table 1, the following were used.
Limonite; LMB 50 (made by Nippon Limonite Co., Ltd .; limonite mined from a mine aged for 3 years, crushed by a spike mill and classified using a sieve, mainly composed of goethite, average particle diameter 50 μm, L ^* Lightness L ^{* of the} a ^* b ^* color space: 38.2, chromaticity a ^* : 40.5, b ^* : 51.8)
Iron oxide (III); reagent (Kanto Chemical Co., Ltd.)
Iron oxide ferric oxide; reagent (made by Kanto Chemical Co., Ltd.)
Iron; Iron powder with an average particle size of 60 to 80 μm (manufactured by Kanto Chemical Co., Ltd.)

The coating ratio shown in Table 1 means the ratio of the weight of the coated layer of the coated rice seed meal to the dried weight (weight of coated layer / weight of dried weight).
In addition, in the column of presence or absence of seeding shown in Table 1, the case where the dried bread which is not subjected to the seeding treatment is loaded in the granulation pan of the tumbling granulator is described as "none", and the rice seed subjected to the seeding treatment The case where the seed meal was loaded was described as "yes".

(Examples 2 and 3)
Coated rice seed pods of Examples 2 and 3 were obtained in the same manner as Example 1, except that iron oxide powder shown in Table 1 was used.

(Comparative example 1)
The rice which has been subjected to the soaking treatment which is immersed in water having a water temperature of 12.5 ° C. for 4 days, in place of the rice not using the soaking treatment used in Example 1, in place of the rice not having the soaking treatment. A coated rice seed meal of Comparative Example 1 was obtained in the same manner as in Example 1 except that the seed meal was used.

(Comparative example 2)
A coated rice seed meal of Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that iron powder was used in place of iron oxide powder.

After storing the coated rice seed meal of Examples 1 to 3 and Comparative Examples 1 and 2 for 3 days under an environment of a temperature of 20 ° C. and a humidity of 40%, a germination test was conducted by the method shown below.
Germination test
Water was placed in a glass water tank, and a 1.5 mm mesh stainless steel mesh was placed 8 mm below the water surface. Thirty-two coated rice seeds were placed on the mesh and cultivated while maintaining the water surface height in a temperature-controlled room at 25 ° C. The presence or absence of germination was visually confirmed every one hour after the start of cultivation. Then, for each of the coated rice seeds of Examples 1 to 3 and Comparative Examples 1 and 2, the time when germination was first confirmed (emergence (A)), the time when all coated rice seeds germinated, or saturation ( Check the time for all germination except for seed meal which does not germinate even if cultivation is continued) (emergence rate 100% time (B)), time from the beginning of germination (A) to 100% time (B) (B) It asked for -A). The results are shown in Table 1.

(Example 4)
A coated rice seed meal was produced in the same manner as in Example 1 except that the coating ratio shown in Table 1 was used, and a germination test was conducted in the same manner as in Example 1. The results are shown in Table 1.
(Example 5)
A germination test was carried out in the same manner as in Example 1 except that the coated rice seed meal of Example 1 was used and the cultivation temperature was as shown in Table 1. The results are shown in Table 1.
(Example 6)
A germination test was conducted in the same manner as in Example 1 except that using the coated rice seed meal of Example 4 and the cultivation temperature shown in Table 1. The results are shown in Table 1.

As shown in Table 1, in Examples 1 to 6, the time from the beginning of germination (A) to the germination rate of 100% time (B) as compared to Comparative Example 1 and Comparative Example 2 subjected to the immersion treatment (B-A) was short, and individual differences in germination timing were small.
Moreover, in Examples 1 to 6, compared with Comparative Example 1 and Comparative Example 2, the onset of germination (A) was delayed.

Also, according to the results of Example 1 and Example 4, according to the results of Example 5 and Example 6, by using a coated rice seed meal having a small coating ratio (Examples 4 and 6), the germination starts (A), the germination rate It turned out that both 100% time (B) and (B-A) become a short time.
In addition, Example 1 using limonite as the powder of iron oxide is compared with Example 2 using iron (III) oxide as the powder of iron oxide and Example 3 using iron trioxide , Germination (A), germination rate 100% time (B) was a short time.

In addition, for the coated rice seed meal of Example 1 and Comparative Example 1, the relationship between the elapsed time (immersion time) from the start of cultivation and the germination rate is shown in FIG. In FIG. 1, ○ indicates the result of Example 1, and □ indicates the result of Comparative Example 1.
As shown in FIG. 1, in Example 1, the germination rate is 0% when immersed for 50 hours, and the germination rate when immersed for 90 hours is 90% or more, compared with Comparative Example 1; Individual differences in timing were small. Moreover, as shown in FIG. 1, in Example 1 and the comparative example 1 in immersion time 110 hours or more, the germination rate was equivalent.

Claims (4)

A coating step of forming a coating layer containing iron oxide powder and a resin on the surface of the dry rice bran to make a coated rice seed meal;
And a seeding process for seeding the coated rice seed meal in a field.   The method according to claim 1, wherein the iron oxide comprises limonite.   The resin comprises one or more selected from the group consisting of vinyl acetate polymer resin, acrylic ester copolymer resin, ethylene / vinyl acetate / acrylic acid copolymer resin, and ethylene / vinyl acetate copolymer resin The method for raising seedlings of a rice seed meal according to claim 1 or 2.   4. The coated rice seed meal according to any one of claims 1 to 3, wherein the germination rate is 0% when immersed in water at 25 ° C. for 50 hours and 90% or more when immersed in water for 90 hours. The method for raising seedlings of rice seed meal described in the section.

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