JP2017023125A - Coated rice seed and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide coated rice seeds that enable direct seeding and have a fertilizer effect while suppressing a material cost in comparison with the conventional coated rice seeds coated by metal iron powder and iron oxide, and provide a manufacturing method of the coated rice seeds.SOLUTION: Coated rice seeds concerning the present invention are configured such that the rice seeds are coated by: steel slag containing CaO of 25 mass% or more and 50 mass% or less and SiOof 8 mass% or more and 30 mass% or less; the steel slag containing CaO of 25 mass% or more and 50 mass% or less, SiOof 8 mass% or more and 30 mass% or less, MgO of 1 mass% or more and 20 mass% or less, AlOof 1 mass% or more and 25 mass% or less, Fe of 5 mass% or more and 35 mass% or less, Mn of 1 mass% or more and 8 mass% or less, and POof 0.1 mass% or more and 5 mass% or less; dephosphorization slag; and decarbonizing slag; or both of the dephosphorization slag and the decarbonizing slag.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coated rice seed and a method for producing the coated rice seed, and more particularly to a coated rice seed coated with steelmaking slag and a method for producing the coated rice seed.

  Rice is a very important food stapled by about 2 billion people worldwide. In Japan, it is important to be able to produce and supply rice stably and raise the self-sufficiency rate. In addition, economic development is remarkable in regions such as Southeast Asia where rice is a staple food, and stable rice production and stable rice supply in these regions are becoming increasingly important. .

  In rice cultivation, there are a cultivation method in which seeds (seed seeds) are germinated to grow seedlings, and the seedlings are planted in rice, and a cultivation method by direct seeding of seeds (seed seeds). Rice harvesting by rice planting is the mainstream in Japan because it can harvest homogeneous and high quality rice. However, raising seedlings by seeding rice seeds (seedlings) and growing rice seedlings and planting rice seedlings are labor-intensive, which is a major cost factor.

  On the other hand, in direct sowing, there are problems such as seeds being washed away by water and sowed seeds being eaten by birds. Techniques using seeds coated with iron oxide or iron powder have been reported as methods for solving seed erosion in direct sowing cultivation and bird damage that can be eaten by birds (for example, Patent Documents 1 to 6 below) See).

  In the following Patent Document 1, the seed coating material containing triiron tetroxide as an active ingredient increases the absorption of solar heat by utilizing the fact that triiron tetroxide is black, and oxygen from triiron tetroxide. It has been reported that the feeding can promote germination even under low temperature conditions.

  In the following Patent Document 2, iron powder is adhered to the surface of rice seeds by rust generated by oxidation reaction of metallic iron powder by adding water to the seeds added with iron powder and sulfate or chloride. It has been reported that iron powder-coated seeds can be produced by solidification. Patent Document 2 below describes that the material used for seed coating is preferably close to neutrality.

  In Patent Document 3 below, since the specific gravity of the seed coated with iron increases, there is a problem that it becomes difficult to establish a seedling when the seed is submerged in the soil, and it takes time to form iron rust. Therefore, gypsum is used to promote the formation of rust, but when gypsum is used, the formation of rust is strongly promoted, and heat generation due to oxidation of iron increases, resulting in the death of seeds due to high temperatures. Etc. are described. In the following Patent Document 3, a molybdenum material or a tungsten material is reported as a binding material or a binding promoting material for iron powder instead of gypsum.

  In Patent Document 4 below, in order to avoid bird damage and floating seedlings, when directly seeding rice seeds coated with iron material and quickly sunk the seeds under the water surface, increasing the amount of iron material used for coating is It describes that the cost is increased and the work of covering is laborious. In Patent Document 4 below, it is reported that the amount of iron material used can be reduced by coating the inside in contact with the seed with an iron material and coating the outside with an inexpensive bentonite.

  In the following Patent Document 5, as the rice seed coating iron powder, those having a small particle diameter are preferable, the mass ratio of the iron powder having a particle diameter of 63 μm or less is 0% to 75%, and the particle diameter is 63 μm. It has been reported that the mass ratio of iron powder exceeding 150 μm exceeds 25% to 100% and the mass ratio of iron powder exceeding 150 μm in particle diameter is 0% to 50%. Moreover, in the following patent document 5, it is reported that the iron powder manufactured by the reduction method or the atomizing method is preferable.

  In the following Patent Document 6, it has been reported that a seed coating material containing iron powder as a main material contains flake powder in order to realize a coating in which iron powder is less likely to fall off during seeding or transportation.

JP-A-3-236703 JP 2005-192458 A JP 2012-239594 A JP 2014-90671 A JP 2012-70728 A JP 2014-45701 A

  As described above, various techniques for coating seeds with iron powder have been reported to enable direct seeding of rice seeds. However, these techniques have the following problems.

  First, the seed coating material of Patent Document 1 containing iron trioxide as an active ingredient enhances solar heat absorption and supplies oxygen to the seed from the iron trioxide to germinate even under low temperature conditions. Describe the problem of how to promote In this method, in order to coat the seed with iron trioxide, the seed is coated with a porous material such as boiling stone or a solidified material such as calcium sulfate (gypsum) mixed with iron trioxide. . Therefore, in addition to the cost of materials used for mixing these, it takes time and effort to coat seeds.

  In addition, by adding water to the rice seed of the above-mentioned Patent Document 2 to which iron powder and sulfate or chloride are added, the iron powder adheres to the rice seed by rust generated by the oxidation reaction of metallic iron powder. A problem is described about the method of solidifying and manufacturing an iron powder covering seed. In this method, as described in Patent Document 3, the adhesion and solidification of the iron powder to the seed is realized by rust generated by oxidation of the metal iron powder, so it takes time to form rust. There is a problem. In addition, when sulfate such as gypsum or chloride is added, rust formation is promoted, but there is a problem that seeds become high temperature due to reaction heat and in some cases die. In addition, metal iron powder is expensive and expensive. Moreover, the said patent document 2 describes that it is preferable that the material used for seed coating | cover is near neutrality. In fact, the seed coating materials using triiron tetroxide and iron powder are limited to those close to neutrality. Since adverse effects are expected on the growth of plants, it is considered that coating materials that are close to neutrality have been used in the prior art. Therefore, for example, an alkaline material that can be used for seed coating has not been developed so far.

  With respect to the method of using molybdenum material or tungsten material as a binding material or binding promoter for iron powder in place of gypsum in Patent Document 3, in addition to metal iron powder, molybdenum material and tungsten material are used, so the cost is low. There is a problem that it takes.

  In order to reduce the relative amount of iron material used in Patent Document 4, the cost of the metal iron powder is related to the method of coating the inside in contact with the seed with iron material and coating the outside with inexpensive bentonite. Although it may be able to be reduced to some extent, there is a problem that it requires labor for the coating work because it also requires bentonite coating.

  Patent Document 5 describes that iron powder having a fine particle size is preferable for the rice seed coating iron powder. Many bristles grow on the surface of rice seeds. It is self-evident that the powder cannot be attached to the seed surface unless the iron powder has a particle size smaller than the bristle spacing. In addition, the iron powder suitable for the rice seed coating iron powder in Patent Document 5 is preferably a reduction method or an atomization method. Manufactured by the atomizing method, it is obvious.

  The method for reducing the cost of metallic iron powder for the method of suppressing the detachment of the iron powder coating by including the flake powder in the seed coating material containing iron powder as a main material in Patent Document 6 above However, there is a problem that the material used as the flake powder is expensive. Moreover, since the coating in the state where the flaky powder is added is required, there is also a problem that a labor is required for the coating operation.

  As described above, rice seed coating using iron powder has a problem that metal iron powder is costly.

  In addition, rice seed coating using iron powder or iron tetroxide has a problem that iron is the only element that can be expected to have a fertilizer effect.

  In addition, fine iron powder with a fine particle size used for seed coating requires attention to ignition and dust explosion, and there is a problem that it is costly for safety measures to handle by ordinary farmers. It was.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to suppress the material cost compared to conventional coated rice seeds coated with metal iron powder or iron oxide. An object of the present invention is to provide a directly sown coated rice seed having a fertilizer effect and a method for producing the coated rice seed.

  In view of the above problems, the present inventors have intensively studied a covering material having a relatively low material cost and a fertilizer effect, and have come to consider that steel slag produced as a by-product in the steel manufacturing process can be applied. It was. However, conventionally, neutral materials such as iron powder have been used as seed coating materials, and substances with strong alkalinity have been considered unsuitable for seed coating materials. As a result, even though some types of steelmaking slag are alkaline at a pH of about 11, seeds can germinate even when used as seed coating materials, and the growth of plants is promoted by minerals supplied from steelmaking slag. The present invention relating to rice seeds coated with steelmaking slag was completed.

The summary of this invention completed based on the said knowledge is as follows.
(1) Coated rice seed, wherein the rice seed is covered with a steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ .
(2) 25% by mass to 50% by mass of CaO, 8% by mass to 30% by mass of SiO ₂ , 1% by mass to 20% by mass of MgO, and 1% by mass to 25% by mass of Al Steelmaking slag containing ₂ O ₃ , 5 mass% to 35 mass% Fe, 1 mass% to 8 mass% Mn, and 0.1 mass% to 5 mass% P ₂ O ₅ The rice seed is coated with the rice seed.
(3) A coated rice seed in which rice seed is coated with one or both of dephosphorization slag and decarburization slag, which is a type of steelmaking slag.
(4) Rice seeds are produced by a mixture of steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ with one or both of gypsum and iron powder. Coated rice seed that is coated.
(5) 25% to 50% by weight of CaO, 8% to 30% by weight of SiO ₂ , 1% to 20% by weight of MgO, 1% to 25% by weight of Al ₂ O ₃ Steelmaking slag containing 5 mass% to 35 mass% Fe, 1 mass% to 8 mass% Mn, and 0.1 mass% to 5 mass% P ₂ O ₅ , gypsum, iron powder The rice seed is covered with a mixture of one or both of the rice seeds.
(6) Coated rice seed, wherein rice seed is coated with a mixture of one or both of dephosphorization slag and decarburization slag, which is a kind of steelmaking slag, and one or both of gypsum and iron powder.
(7) The coated rice seed according to any one of (1) to (6), wherein the rice seed is a rice seed coated with starch.
(8) The coated rice seed according to any one of (1) to (7), wherein a surface of the coated rice seed is further coated with gypsum.
(9) The coated rice seed according to any one of (1) to (8), wherein the coated portion of the coated rice seed further contains molasses.
(10) The rice seed is coated with a mixture obtained by mixing steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ with water. A method for producing coated rice seeds, wherein the mixture is consolidated.
(11) 25% to 50% by weight of CaO, 8% to 30% by weight of SiO ₂ , 1% to 20% by weight of MgO, 1% to 25% by weight of Al ₂ O ₃ Steelmaking slag containing ₅ % by mass to 35% by mass Fe, 1% by mass to 8% by mass Mn, and 0.1% by mass to 5% by mass P ₂ O ₅ , and water. A method for producing coated rice seeds, comprising coating rice seeds with a mixture obtained by mixing and solidifying the mixture.
(12) Coated rice which covers rice seeds with a mixture obtained by mixing one or both of dephosphorization slag and decarburization slag, which is a kind of steelmaking slag, and water, and solidifies the mixture. Seed production method.
(13) 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of a steelmaking slag containing SiO ₂ , water, and one or both of gypsum and iron powder are mixed. A method for producing coated rice seeds, comprising coating rice seeds with the obtained mixture and solidifying the mixture.
(14) 25% to 50% by weight of CaO, 8% to 30% by weight of SiO ₂ , 1% to 20% by weight of MgO, 1% to 25% by weight of Al ₂ O ₃ Steelmaking slag containing ₅ % by mass to 35% by mass Fe, 1% by mass to 8% by mass Mn, and 0.1% by mass to 5% by mass P ₂ O ₅ , water, and gypsum A method for producing coated rice seeds, comprising coating rice seeds with a mixture obtained by mixing one or both of iron powders and solidifying the mixture.
(15) Covering rice seeds with a mixture obtained by mixing one or both of dephosphorization slag and decarburization slag, which is a type of steelmaking slag, and one or both of water, gypsum and iron powder. A method for producing coated rice seeds, wherein the mixture is consolidated.
(16) The coated rice according to any one of (10) to (15), wherein a mass ratio of water in the mixture is 10% by mass to 80% by mass with respect to a total mass of the mixture. Seed production method.
(17) The method for producing a coated rice seed according to any one of (10) to (16), wherein the water is water containing 10% by mass to 50% by mass of waste molasses.
(18) The method for producing a coated rice seed according to any one of (10) to (17), wherein a rice seed immersed in an aqueous starch solution is used as the rice seed.
(19) The method for producing coated rice seeds according to any one of (10) to (18), wherein the surface of the consolidated mixture is further coated with gypsum.
(20) The surface of the solidified mixture is further moistened with water containing 0.5% by mass or more and 5% by mass or less of sodium alginate, and then the solidified mixture is dried. (10) to (19) A method for producing a coated rice seed according to any one of the above.

  As described above, according to the present invention, rice for direct sowing can be easily grown at low cost and with good growth by using rice seed coated with steelmaking slag, dephosphorization slag or decarburization slag containing the predetermined component according to the present invention. It becomes possible to produce seeds.

FIG. 5 is a graph showing the results of Example 2. FIG. 5 is a graph showing the results of Example 2. FIG. 6 is a graph showing the results of Example 3. FIG. 6 is a graph showing the results of Example 3. FIG. 10 is a graph showing the results of Example 4. FIG. 6 is a graph showing the results of Example 5.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

<About steelmaking slag>
First, in the embodiment of the present invention, steel slag used for covering rice seeds will be described in detail.

  Steelmaking slag is produced in large quantities as a by-product of the steel industry, and the composition of steelmaking slag is analyzed and managed. Steelmaking slag contains various fertilizer active elements such as Ca, Si, Mg, Mn, Fe, and P, and is used as a fertilizer raw material. In Japan, fertilizers that use steelmaking slag as raw materials include fertilizers that are stipulated by the Fertilizer Control Law and that belong to the standards of mineral silicic acid fertilizer, mineral phosphoric acid fertilizer, by-product lime fertilizer, and special fertilizer (including iron). . In Japan alone, about 10 million tons of steelmaking slag is produced annually, and steelmaking slag is available at low cost.

  Steelmaking slag is a material that is less expensive and less expensive than iron powder, is inexpensive, and has been conventionally used for fertilizer applications.

  In this embodiment, as the steelmaking slag used for covering rice seeds, for example, in addition to steelmaking slag containing predetermined components as described in detail below, a kind of steelmaking slag by-produced from the steel production process Examples thereof include dephosphorization slag and decarburization slag. In addition, dephosphorization slag is slag containing phosphorus by-produced by adding lime, iron oxide or the like as a dephosphorization agent to hot metal and blowing gas such as oxygen in order to remove phosphorus contained in hot metal, A type of steelmaking slag. The decarburized slag is a slag that is produced as a by-product by blowing oxygen into the hot metal in order to make the steel excluding the carbon contained in the hot metal, and is a kind of steelmaking slag.

  Of course, any steelmaking slag other than these can be used as long as it satisfies the composition of the steelmaking slag used for coating the rice seeds of the present invention. For example, in addition to steelmaking slag containing a predetermined amount of components as will be described in detail below, steelmaking slag containing a high content of magnesium, which is generated when repairing a refractory, can be used.

  In this embodiment, steelmaking slag, dephosphorization slag, or decarburized slag adjusted to an appropriate particle size by pulverization or the like can be used as it is as slag used for covering rice seeds. For pulverization of these slags, known means such as a jaw crusher, a hammer crusher, a rod mill, a ball mill, a roll mill, and a roller mill can be used.

  In this embodiment, the particle size of steelmaking slag, dephosphorization slag or decarburization slag used for coating rice seeds is not particularly limited as long as the rice seeds are coated by solidification, but the particle size is fine. It can be said that it is preferable because it tends to solidify. In particular, those having a particle size adjusted to less than 600 μm tend to increase the adhesion to rice seeds, and are highly effective. Therefore, it is preferable to adjust all the particle sizes of the steelmaking slag, dephosphorization slag or decarburization slag used for the rice seed coating according to this embodiment to be less than 600 μm. For example, all the particle diameters can be made less than 600 μm by screening slag used for covering rice seeds. Of course, a slag having a finer particle size is of course preferable for increasing the adhesion to rice seeds, but excessive pulverization is not necessary because grinding and classification require cost and time.

○ Steelmaking Slag Containing Predetermined Components In this embodiment, the composition of steelmaking slag covering rice seeds will be described in detail. The steelmaking slag containing a predetermined amount of components used in the present embodiment contains a predetermined amount of various components such as Ca, Si, Mg, Mn, Fe, and P as described above.

[CaO: 25% by mass to 50% by mass]
First, Ca will be described.
When steelmaking slag comes into contact with water, Ca and Si and Al described later are eluted and chemically bonded, thereby exhibiting hydraulic properties. The present invention uses this hydraulic property to attach and solidify steelmaking slag to rice seeds to coat the rice seeds. Therefore, Ca is an important element. Ca is also an essential fertilizer element for plants. When noting the Ca content with fertilizer or steelmaking slag, the Ca content is expressed in terms of CaO since it is expressed in terms of oxide CaO.

  In this embodiment, when the content of CaO in the steelmaking slag used for covering rice seeds is less than 25% by mass, there is a possibility that a sufficient amount of Ca cannot be eluted to develop hydraulic properties. On the other hand, steelmaking slag having a CaO content exceeding 50% by mass is not produced by a normal ironmaking process and is difficult to obtain. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and is preferably generated by a normal ironmaking process. Therefore, in this embodiment, the content of CaO in the steelmaking slag used for covering rice seeds is set to 25% by mass or more and 50% by mass or less. The content of CaO in the steelmaking slag is preferably 38% by mass or more and 50% by mass or less.

  The content of CaO can be measured by, for example, fluorescent X-ray analysis.

[SiO ₂ : 8% by mass to 30% by mass]
Next, Si will be described.
Si, together with Ca and Al, is an element that contributes to the hydraulic properties of steelmaking slag. Therefore, Si is also an important element. Moreover, Si is a fertilizer effect element very important for rice, though it is not an essential element of plants. Silicic acid (SiO ₂ ) accounts for about 5% of the dry weight of the plant of rice. In fertilizer and steelmaking slag, when describing the Si content, the content is expressed in terms of the oxide SiO _2, and hence the Si content will be expressed as SiO ₂ hereinafter.

In the present embodiment, when the content of SiO ₂ in the steelmaking slag used for covering rice seeds is less than 10% by mass, there is a possibility that a sufficient amount of Si cannot be eluted to develop hydraulic properties. . On the other hand, steelmaking slag having a SiO ₂ content of more than 30% by mass is not produced by a normal steelmaking process and is difficult to obtain. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Therefore, in this embodiment, the content of SiO ₂ in the steelmaking slag used for covering rice seed is 10% by mass or more and 30% by mass or less.

The content of SiO ₂ can be measured by, for example, fluorescent X-ray analysis.

[MgO: 1% by mass to 20% by mass]
Subsequently, Mg will be described.
In general, the MgO content of steelmaking slag is considerably lower than the CaO content. This is because steelmaking slag is slag generated mainly by adding lime to hot metal. Mg contained in the steelmaking slag is mainly caused by Mg eluted from the refractory bricks on the furnace wall of the blast furnace or converter. Mg, together with Ca, Si, and Al, is an element related to the hydraulic properties of steelmaking slag. However, the contribution of Mg to hydraulic properties, such as the difference between the CaO content and the MgO content contained in steelmaking slag, is small compared to Ca. In this embodiment, the steelmaking slag used for covering rice seeds contains CaO in an amount of 25% by mass or more. Therefore, it is considered that the hydraulic property can be basically covered by CaO contained in the steelmaking slag. However, it can be expected that hydraulic properties are better expressed by the further presence of MgO. In the fertilizer and steelmaking slag, when the content of Mg is expressed, the content is expressed in terms of MgO as an oxide. Therefore, hereinafter, the content of Mg is expressed as MgO.

  Here, steelmaking slag having a content of MgO of less than 1% by mass does not occur in a normal ironmaking process. On the other hand, in the steelmaking slag generated in the refractory repair of the converter, the MgO content is close to 20%. However, steelmaking slag having an MgO content exceeding 20% does not occur. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Therefore, in this embodiment, it is preferable that the content of MgO in the steelmaking slag used for covering rice seeds is 1% by mass or more and 20% by mass or less. The content of MgO in the steelmaking slag is more preferably 3% by mass or more and 10% by mass or less.

  The content of MgO can be measured by, for example, fluorescent X-ray analysis.

_[Al 2 _O 3: 1% by mass to 25% by mass]
Subsequently, Al will be described.
Along with Ca and Si, Al is an element important for the hydraulic properties of steelmaking slag. In fertilizers and steelmaking slag, when the content of Al is expressed, the content is expressed in terms of oxide Al ₂ O _3, and hence the content of Al will be expressed as Al ₂ O ₃ hereinafter.

Steelmaking slag content of Al ₂ O ₃ is less than 1 wt%, and, steelmaking slag content of Al ₂ O ₃ of 25 wt% excess is not generated in the normal steelmaking process, is difficult to obtain is there. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Further, if it is more than 1 mass% content of _Al 2 _{O 3} of steel slag, Al can indicate hydraulic with Ca and Si. Therefore, in this embodiment, it is preferable that the content of Al ₂ O _{3 in} the steelmaking slag used for covering rice seeds is 1% by mass or more and 25% by mass or less. However, when it is desired to further increase the hydraulic property and promote consolidation, in this embodiment, the content of Al ₂ O ₃ in the steelmaking slag used for covering rice seeds is 10% by mass or more and 25% by mass or less. More preferably.

Note that the content of Al ₂ O ₃ can be measured by, for example, fluorescent X-ray analysis.

[Fe: 5% by mass to 35% by mass]
Subsequently, Fe will be described.
Fe is an element inevitably contained in steelmaking slag. Fe is not an essential element of plants, but iron is also an effective element for plants, as iron-containing materials are in special fertilizers defined by the Fertilizer Control Law. Steelmaking slag having an Fe content of less than 5% by mass and steelmaking slag having an Fe content exceeding 35% by mass are not produced by a normal ironmaking process and are difficult to obtain. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Therefore, in the present embodiment, the content of Fe in the steelmaking slag used for covering rice seeds is preferably 5% by mass or more and 35% by mass or less. The content of Fe in the steelmaking slag is more preferably 10% by mass or more and 25% by mass or less.

  The Fe content can be measured by, for example, fluorescent X-ray analysis.

[Mn: 1% by mass to 8% by mass]
Next, Mn will be described.
Mn is an element that has a fertilizer effect on plants. Steelmaking slag having a Mn content of less than 1% by mass and steelmaking slag having a Mn content of more than 8% by mass are not produced by a normal ironmaking process and are difficult to obtain. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Therefore, in this embodiment, it is preferable that the Mn content of the steelmaking slag used for covering rice seeds is 1% by mass or more and 8% by mass or less.

  The content of Mn can be measured by, for example, fluorescent X-ray analysis.

_[P 2 _O 5: 0.1% to 5% by weight]
Next, P will be described.
P is an essential element of plants. In fertilizer and steelmaking slag, when describing the content of P, since the content is expressed in terms of oxide P ₂ O ₅ , the steelmaking slag used for covering rice seeds in this embodiment Represents the content as P ₂ O ₅ . P is an element that acts on the root growth point and is effective in root growth. When P is insufficient, root growth is suppressed. However, steel slag content of P ₂ O ₅ is less than 0.1 wt%, and, steelmaking slag content of P ₂ O ₅ is 5 wt% excess is not generated in the normal steel manufacturing process, It is difficult to obtain. In this embodiment, it is preferable that the steelmaking slag used for covering rice seeds can be stably supplied in a large amount, and it is preferable that the steelmaking slag is generated by a normal steelmaking process. Therefore, in this embodiment, it is preferable that the content of P ₂ O ₅ in steelmaking slag used for covering rice seeds is 0.1% by mass or more and 5% by mass or less.

Note that the content of P ₂ O ₅ can be measured, for example, by fluorescent X-ray analysis.

Accordingly, in this embodiment, the composition of the steelmaking slag used for the coating of rice seed, at least, the content of CaO is less than 25 wt% to 50 wt%, the content of SiO ₂ is 10% by weight to 30% by weight It is. In addition to the above CaO and SiO ₂ , the composition of the steelmaking slag is such that the content of MgO is 1% by mass to 20% by mass, the content of Al ₂ O ₃ is 1% by mass to 25% by mass, The content is 5% by mass to 35% by mass, the Mn content is 1% by mass to 8% by mass, and the content of P ₂ O ₅ is 0.1% by mass to 5% by mass. preferable.

  In such a steelmaking slag composition, the CaO content is 25% by mass or more and 50% by mass or less, and the rice seed coated with the steelmaking slag can germinate despite being alkaline. It is known that gramineous plants secrete acidic substances capable of chelating iron ions such as mugineic acid from the roots as a reason why they can germinate despite alkalinity. Even in rice seeds at the time of germination, such an acidic substance is secreted from the roots, and normal germination is made possible by neutralizing the alkali caused by the steelmaking slag that covered the seeds. Conceivable. In addition, due to the secretion of such an acidic substance, iron contained in the steelmaking slag is chelated as iron ions, so that it can be easily absorbed from the radicle.

○ About dephosphorization slag and decarburization slag The dephosphorization slag and decarburization slag also contain the same components as the steelmaking slag containing the above-mentioned predetermined amount of components, but the contents are various components in the steelmaking slag. It may be different from the content of. However, in the case of dephosphorization slag and decarburization slag, the slag for covering rice seeds in this embodiment is present even if there is a component having a different content from the steelmaking slag containing the above-mentioned predetermined amount of component. It can be used as

<Measurement method of content of each component in steelmaking slag>
As described above, in the present embodiment, the content of each component in various slags used for covering rice seeds can be measured by fluorescent X-ray analysis. More specifically, a calibration curve is created by measuring in advance the peak intensity of fluorescent X-rays related to the component of interest using a standard sample whose content is known for the component of interest. For samples whose content is unknown, the peak intensity of fluorescent X-rays related to the component of interest can be measured, and the content of the component of interest can be specified by using a calibration curve prepared in advance. .

  The fluorescent X-ray peak of interest is not particularly limited, but for example, attention should be paid to the fluorescent X-ray peaks of Ca, Si, Mg, Al, Fe, Mn, and P.

  In addition, the measuring method of content of each component in various slag is not limited to the above fluorescent X-ray analysis methods, It is possible to use other well-known analysis methods suitably.

<About rice seeds>
Next, rice seeds that can be used as the coated rice seeds according to the present embodiment will be briefly described.
The type of rice seed that can be used in the coated rice seed according to the present embodiment is not particularly limited, and for example, any rice seed such as a plant seed belonging to the genus Gramineae can be used. Is possible.

<About the method for producing coated rice seeds>
Subsequently, a method for producing a coated rice seed using steelmaking slag, dephosphorization slag or decarburization slag as described above will be described in detail.

  Rice seeds that coat steelmaking slag, dephosphorization slag, or decarburization slag are also referred to as seed fir. By mixing water with steelmaking slag, dephosphorization slag or decarburization slag used for covering rice seeds, these slags have the property of solidifying. The mixing ratio of water added to steelmaking slag, dephosphorization slag or decarburization slag, but the mass ratio of water in the mixture of slag and water (that is, the mass ratio of water to the total mass of the mixture) is 10 mass% or more. It is preferable that it is 80 mass% or less. When the mass ratio of the water in the mixture of the slag and water is less than 10% by mass, the adhesion of the slag to the rice seed surface is deteriorated, and the possibility that the coating is difficult is increased. On the other hand, when the mass ratio of water in the mixture of slag and water exceeds 80 mass%, the ratio of water is too high, so that the possibility that the surface of rice seeds cannot be covered with the slag is increased. . Therefore, the mass ratio of water in the mixture of slag and water is preferably 10% by mass or more and 80% by mass or less. In order to achieve stable seed coating using steelmaking slag, the mass ratio of water is more preferably 25% by mass or more and 50% by mass or less.

  Next, a method for coating rice seeds with a mixture of steelmaking slag, dephosphorization slag or decarburization slag with water will be described. By preparing a mixture in which the slag is mixed with water in advance and mixing this mixture with rice seeds, the rice seeds can be coated. Alternatively, the rice seed can be coated with the slag by mixing the slag, rice seed and water together. The mixing method may be any method. When processing in large quantities, it is also possible to coat the rice seeds with the slag by mixing using a rotary granulator.

  Rice seeds coated with steelmaking slag, dephosphorization slag or decarburization slag are taken out and used. In addition, although it is the quantity coat | covered with the said slag, it is not specifically limited. More preferably, when the mass of the rice seed is 1, such a rice seed is preferably covered with the slag having a mass of about 0.1 to 2. Usually, the coating amount realized only by mixing rice seeds into a mixture of slag and water falls within the above range. However, when slag is not entirely covered on the surface of the rice seed, it is preferable to mix the rice seed with the mixture of slag and water again.

  In order to increase the consolidation of the slag, blast furnace slag fine powder or calcium sulfate, steelmaking slag, dephosphorization slag or decarburization slag, steelmaking slag, dephosphorization slag or decarburization slag and water mixture, or steelmaking slag, It is also effective to add to a mixture of dephosphorized slag or decarburized slag, water and rice seeds.

  When rice seed is coated with steelmaking slag, there is a possibility that the adhesion of the coating to the seed surface becomes weak due to the bristles present on the seed surface. One way to solve this phenomenon is to immerse rice seeds in an aqueous starch solution and then coat with steelmaking slag. By such treatment, the adhesion of the coating can be increased. The concentration of the aqueous starch solution (that is, the mass ratio of starch to the total mass of the aqueous solution) is preferably 40% by mass to 80% by mass. After immersing the rice seed in an aqueous starch solution, the ratio of the mass of one rice seed to the mass of the coating is increased to about 1: 0.6 to 1: 2 by coating the rice seed with steel slag. It is possible.

  It is also possible to coat rice seeds coated with steel slag with gypsum from the outside. By covering the rice seeds with steelmaking slag and gypsum, adhesion to the rice seeds by the steelmaking slag coating can be enhanced. As a method for coating the steel seeds coated with steelmaking slag from the outside, for example, the coated rice seeds coated with steelmaking slag and dried are dipped in a water suspension of gypsum and taken out at room temperature. It is feasible by using a method of drying. The concentration of the aqueous suspension of gypsum is preferably 20% by mass to 60% by mass, for example.

  It is also possible to coat rice seeds with a mixture of steelmaking slag and gypsum and / or iron powder. When the steelmaking slag used for covering rice seed is insufficient, gypsum can be used as a complementary material for the insufficient steelmaking slag. In this case, gypsum is mixed with steelmaking slag. Since iron powder has a large specific gravity, it has the effect of increasing the weight of the coated seed and making it more difficult for the paddy fields to run away. When covering rice seeds with a mixture of steelmaking slag and gypsum and / or iron powder, mix the steelmaking slag with gypsum and / or iron powder in advance and immerse the rice seeds in a suspension to which water has been added. Then, it can be taken out and dried at room temperature for coating.

  When adding gypsum to steelmaking slag, it is preferable that the ratio of gypsum with respect to steelmaking slag does not exceed 20 mass%. If the percentage of gypsum added to the steelmaking slag exceeds 20% by mass, the percentage of gypsum is too high, which may reduce the germination rate. Moreover, also when adding iron powder to steelmaking slag, it is preferable that the mass ratio of the iron powder with respect to steelmaking slag does not exceed 50 mass%. When the proportion of iron powder exceeds 50% by mass, the divalent iron ions dissolved from the iron powder are oxidized to trivalent iron ions and become acidic when precipitated as hydroxides. Or the growth of radicles may be adversely affected. Moreover, since iron powder is expensive, if the ratio of iron powder becomes high, it will also become disadvantageous also in cost.

  In addition, when covering rice seeds with a mixture of steelmaking slag and gypsum and / or iron powder, rice seeds are prepared using a mixture of steelmaking slag and gypsum and / or iron powder with water added. Although it coat | covers, it is preferable that the mass ratio (mass ratio of the water with respect to the total mass of the mixture) of water in this mixture is 10 mass% or more and 80 mass% or less. When the mass proportion of water is less than 10 mass%, the adhesion of the steelmaking slag and gypsum and / or iron powder to the surface of the rice seeds becomes poor, and the possibility of difficulty in coating becomes high. On the other hand, when the mass ratio of water in the mixture of steelmaking slag and gypsum and / or iron powder and water exceeds 80% by mass, the ratio of water is too high, There is a high possibility that the steelmaking slag cannot be covered with a mixture of gypsum and / or iron powder. Therefore, it is preferable that the mass ratio of water in the mixture of steelmaking slag, gypsum and / or iron powder and water is 10% by mass or more and 80% by mass or less. In order to stably achieve seed coating using a mixture of steelmaking slag and gypsum and / or iron powder, it is more preferable that the mass ratio of water is 25 mass% or more and 50% mass or less.

<Water used in the production of coated rice seeds>
Water that is mixed with steelmaking slag or a mixture of steelmaking slag and gypsum when the rice seed is coated with steelmaking slag or a mixture of steelmaking slag and gypsum. It is possible to use groundwater, agricultural water, etc., but it is more preferable to use water containing molasses. Waste molasses is a black-brown liquid that is produced as a by-product when sugar is refined from squeezed juice such as sugar cane, and contains about 70 to 80% sugar, and also contains minerals and vitamins. The molasses particularly contains about 2% of potassium necessary for plant cell growth. Potassium is a component that is absorbed from plant roots and necessary for the growth of plant cells. Therefore, by using water containing molasses in the production of coated rice seeds, potassium derived from molasses can be supplied from the produced rice seed coating, and it is expected to further promote the growth of seedlings. it can.

  Since molasses is a by-product, it can be obtained at low cost. By using water containing molasses, the adhesiveness of the molasses can be used to reinforce the stability of the coating and adherence to the seed, and the components contained in the molasses can be Growth can be further promoted in addition to the fertilizer effect produced by steelmaking slag.

  When the mass ratio of the molasses contained in the water containing the molasses is less than 10% by mass with respect to the total mass, solidification of the seed coating consisting of steelmaking slag or a mixture of steelmaking slag and gypsum and seeds The effect of reinforcing the adhesion stability to the surface becomes difficult to express clearly. On the other hand, when the mass ratio of the molasses contained in the water containing molasses exceeds 50% by mass with respect to the total mass, steelmaking slag or a mixture of steelmaking slag and gypsum and the molasses are contained. When water is mixed, steelmaking slag or a mixture of steelmaking slag and gypsum becomes obscured, making it difficult to adhere to seeds. Therefore, it is preferable that the mass ratio of the molasses contained in the water containing molasses is 10% by mass or more and 50% by mass or less with respect to the total mass.

<Surface treatment of coated rice seeds using sodium alginate aqueous solution>
Sodium alginate is a kind of polysaccharide contained in brown algae that are algae. When Ca or Mg is added to an aqueous solution of sodium alginate, it has a property of gelling. Since steelmaking slag contains Ca and Mg, and gypsum contains Ca, gelation occurs by adding a sodium alginate aqueous solution to the surface of steelmaking slag or a mixture of steelmaking slag and gypsum, and steelmaking. It becomes possible to reinforce the stability of adhesion of the seed coating composed of slag or steelmaking slag and gypsum to the seed. When the seeds of coated rice produced using sodium alginate are directly sown on the soil, the alginic acid is decomposed by the action of soil microorganisms to become alginate oligosaccharides. Alginate oligosaccharide has an effect of helping mineral absorption into plant roots by combining with minerals contained in the steelmaking slag of the coating, and an effect of promoting the growth of seedlings after germination can be expected.

  This is a method of adding an aqueous sodium alginate solution to the surface of the seed coating. For example, an aqueous sodium alginate solution is sprayed or sprinkled on the surface of the seed coated with steelmaking slag or steelmaking slag and gypsum. There are ways to do it. It is also possible to perform a method of immersing the steel-coated slag or the seed coated with the steel-made slag and gypsum in a sodium alginate aqueous solution for a short period of time so that the coating does not peel off. In addition, when the concentration of the sodium alginate aqueous solution is less than 0.5% by mass with respect to the total mass of the aqueous solution, the concentration of the sodium alginate is too low, so that gelation does not occur firmly and the coating seeds There is a possibility that the effect of reinforcing the adhesion stability is not exhibited. Moreover, when the density | concentration of the sodium alginate aqueous solution exceeds 5 mass% with respect to the whole mass of aqueous solution, a gel may become too strong and may suppress germination. Therefore, the concentration of the aqueous sodium alginate solution added to the surface of the seed coating made of steel slag or steel slag and gypsum is 0.5% by mass or more and 5% by mass or less with respect to the total mass of the aqueous solution. preferable. In addition, although it is the quantity of the sodium alginate aqueous solution in the case of adding a sodium alginate aqueous solution by spraying or sprinkling, it may be the quantity which wets the whole surface of a seed coating.

  Rice seeds coated with steelmaking slag, dephosphorization slag or decarburization slag can be used for direct sowing after air drying in a well-ventilated place, for example. Since covering reduces air permeability and suppresses the respiration of rice seeds, it is preferable to sow as soon as possible after coating. If possible, it is preferable to sow within 4 days after coating.

  However, the coated rice seeds can be stored and used for direct seeding until the latter half of the year.

  In addition, in the said description, the composition of steelmaking slag is shown by the composition before mixing with water. In order to confirm the composition of the steelmaking slag after mixing with water, the steelmaking slag may be recovered in a state where the water is evaporated and dried, and the composition of the recovered steelmaking slag may be examined. Thus, the component composition of the steelmaking slag before coating is almost the same as the component composition of the steelmaking slag after coating.

  As described above, rice seeds coated with steelmaking slag, dephosphorization slag, or decarburization slag can be easily and inexpensively produced. The coated rice seeds thus prepared can be used for direct sowing, and the efficiency and productivity of rice cultivation can be improved.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to the examples described below.

[Example 1]
Nine types of slags whose compositions are shown in Table 1 were prepared by sieving to a maximum particle size of less than 600 μm. Samples A, C, D, E, and F are steelmaking slag obtained from a converter in a steel process. Sample B is a steelmaking slag obtained from the hot metal pretreatment process. Sample G is dephosphorized slag, and sample H is decarburized slag. Sample I was prepared by mixing both Sample G and Sample H by 50% by mass.

Among these samples, the compositions of the five types of steelmaking slags of Sample A to Sample E all have a CaO content of 25% by mass to 50% by mass and a SiO ₂ content of 8% by mass. % To 30% by mass. The composition of the five types of steelmaking slags of Sample A to Sample E is further such that the content of MgO is 1% by mass to 20% by mass, the content of Al ₂ O ₃ is 1% by mass to 25% by mass, Also satisfied is a composition in which the Fe content is 5% by mass to 35% by mass, the Mn content is 1% by mass to 8% by mass, and the P ₂ O ₅ content is 0.1% by mass to 5% by mass. It was something to do.

  On the other hand, the sample F has a CaO content of 55% and is neither a dephosphorization slag nor a decarburization slag, and thus is a steelmaking slag sample corresponding to a comparative example.

Sample G has a SiO ₂ content of 35.0%, which deviates from the composition of steelmaking slag used for rice seeds in the present invention, but is a dephosphorization slag and is a sample according to the present invention. Sample H is a decarburized slag and is a sample according to the present invention. Sample I is a mixture of dephosphorized slag and decarburized slag, and is a sample according to the present invention.

  Water was added to and mixed with nine types of samples prepared to have a sieved particle size of less than 600 μm so that the mass ratio of water in the mixture of each sample and water was 30%. To each mixture of sample and water, rice seeds (variety: “Fusakogane”) were added and mixed, and the rice seeds were covered with the above samples. The mass of each sample used for coating corresponded to 0.6 when the mass of rice seeds was 1. The coated rice seeds were air dried for 3 hours in a well-ventilated state. As described above, rice seeds coated with the above-described rice seed coating material were produced. The surface of the produced rice seed was entirely covered with the sample.

  A sodium chloride aqueous solution (specific gravity 1.4) was prepared, and it was examined whether each of the nine kinds of rice seeds coated with slag and uncoated rice seeds settled. As shown in Table 2, the uncoated rice seeds did not settle, whereas the rice seeds coated with the slag samples A to I all settled. Therefore, it was confirmed that the sedimentation of rice seeds was increased by coating with various slags as described above.

[Example 2]
Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in distilled water, rice seeds coated with each of the nine types of slags shown in Table 1 in the same manner as in Example 1 were placed on a different filter paper for each sample. 25 grains were placed. As a control, a petri dish was also prepared for uncoated rice seed that was not coated with steelmaking slag, and 25 grains were similarly placed on a filter paper soaked in distilled water. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. In addition, for the germinated ones, the lengths of the radicles and seedlings were measured.
Table 3 below shows the results of germination number and germination rate.

  Steelmaking slag is a material exhibiting alkalinity around pH 11, but the rice seed coated with any of Sample A to Sample E of the present invention has a germination rate of about 80%, similar to the uncoated rice seed, It was confirmed that the rice seeds coated with the rice seed coating material of the present invention had the same germination rate as the control uncoated rice seeds. On the other hand, sample F was a steelmaking slag having a high CaO content of 55% and strong alkalinity, so the germination rate was 60%, which was a low germination rate compared to the germination rate of uncoated rice seeds. In sample G which is dephosphorization slag, sample H which is decarburization slag, and sample I prepared by mixing both dephosphorization slag and decarburization slag, the germination rate is 84%, The germination rate was the same.

  In FIG. 1, the average value of the measurement result of the length of the germinated larva was compared with the graph for the seed coated with each sample and the uncoated seed as a control. In FIG. 1, the standard deviation is also shown.

  In FIG. 2, the average value of the measurement result of the germinated seedling length of the seed coated with each sample and the uncoated seed as a control is shown in a graph. In FIG. 2, the standard deviation is also shown.

  As shown in FIG. 1 and FIG. 2, the seeds coated with five types of slags of Sample A to Sample E according to the present invention grew shoots and seedlings after germination rather than control uncoated seeds. The growth of both was promoted. Also, the rice seed coated with sample G, which is a dephosphorization slag, sample H, which is a decarburization slag, and sample I prepared by mixing both dephosphorization slag and decarburization slag, is more than the control uncoated rice seed. Both radicle growth and seedling growth after germination were promoted. On the other hand, in rice seeds coated with Sample F having a high CaO content of 55%, compared to rice seeds coated with Sample A to Sample E, Sample G, Sample H, and Sample I, the growth of young roots and seedlings Both growth were suppressed. However, shoot growth and seedling growth were promoted more than uncoated rice seeds.

Therefore, the content of CaO is 25% by mass or more and 50% by mass or less, the content of SiO ₂ is 10% by mass or more and 30% by mass or less, the content of MgO is 1% by mass or more and 20% by mass or less, and Al ₂ O ₃ The content is 1% by mass to 25% by mass, the Fe content is 5% by mass to 35% by mass, the Mn content is 1% by mass to 8% by mass, and the P ₂ O ₅ content is 0.00. The germination rate of rice seeds coated with steelmaking slag having a composition of 1% by mass or more and 5% by mass or less is equivalent to the uncoated seeds of the control, and the growth of roots and seedlings after germination is compared with the uncoated rice seeds. It was confirmed that it can be promoted. In addition, the germination rate of rice seeds coated with dephosphorization slag and decarburization slag, and a mixture of both dephosphorization slag and decarburization slag is similar to that of the uncoated rice seeds of the control. It was confirmed that seedling growth can be promoted.

[Example 3]
Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. Rice seeds coated with sample B having the maximum particle size of 600 μm and the composition shown in Table 1 on the filter paper soaked in distilled water, and rice coated with pure iron iron powder having the maximum particle size of 600 μm. 25 seeds were placed on each filter paper of different petri dishes. As a control, a petri dish was also prepared for uncoated rice seed that was not coated with steelmaking slag, and 25 grains were similarly placed on a filter paper soaked in distilled water. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. In addition, for the germinated ones, the lengths of the radicles and seedlings were measured.
Table 4 below shows the results of germination number and germination rate.

  The rice seed coated with the sample B of the present invention had a higher germination rate than the uncoated rice seed and the iron powdered rice seed.

  In FIG. 3, the average value of the measurement result of the length of the germinated radicle was compared with a graph. In FIG. 3, the standard deviation is also shown.

  In FIG. 4, the average value of the measurement result of the length of the germinated seedling was compared with a graph. FIG. 4 also shows the standard deviation.

  As shown in FIGS. 3 and 4, the seed coated with the sample B of the present invention is more promoted in both the growth of the seedling and the seedling after germination than the uncoated rice seed and the iron powdered rice seed. It was.

Therefore, the content of CaO is 25% by mass or more and 50% by mass or less, the content of SiO ₂ is 10% by mass or more and 30% by mass or less, the content of MgO is 1% by mass or more and 20% by mass or less, and Al ₂ O ₃ The content is 1% by mass to 25% by mass, the Fe content is 5% by mass to 35% by mass, the Mn content is 1% by mass to 8% by mass, and the P ₂ O ₅ content is 0.00. It can be confirmed that by covering rice seeds with steelmaking slag having a composition of 1% by mass or more and 5% by mass or less, it is possible to obtain coated rice seeds with good growth at a lower cost than coating rice seeds with iron powder. It was.

[Example 4] (Comparison with iron powder)
Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. Rice seeds coated with steelmaking slag sample C having a maximum particle size of 600 μm whose composition is listed in Table 1 by the method described in Example 1 on the filter paper soaked in this distilled water shallowly, and the same maximum particle size 25 seeds of rice seeds coated with 600 μm pure iron powder were placed on different petri dish. As a control, a petri dish was also prepared for uncoated rice seed that was not coated with steelmaking slag, and 20 grains were similarly placed on a filter paper soaked in distilled water. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. Moreover, the length of the radicle was measured about what germinated.
Table 5 below shows the results of germination number and germination rate.

  The rice seed coated with the steelmaking slag sample C of the present invention had a germination rate equivalent to that of the uncoated rice seed, and a higher germination rate than the iron powdered rice seed.

In FIG. 5, the average value of the measurement result of the length of the germinated radicle was compared with a graph.
Seeds coated with the steelmaking slag sample C of the present invention showed larval root growth equivalent to uncoated rice seeds. On the other hand, the growth of radicles after germination was significantly worse in the iron powdered rice seeds.

  As a result of examining the pH of the water remaining in the petri dish, the petri dish water of the uncoated rice seed was pH 5.8 and the petri dish water of the rice seed coated with the sample C was pH 8.0. The petri dish water was acidified to pH 4.0. It is considered that the acidification occurs when iron dissolves into iron hydroxide, and this acidification condition inhibits the growth of radicles after germination of iron-coated rice seeds.

Therefore, the content of CaO is 25% by mass or more and 50% by mass or less, the content of SiO ₂ is 10% by mass or more and 30% by mass or less, the content of MgO is 1% by mass or more and 20% by mass or less, and Al ₂ O ₃ The content is 1% by mass to 25% by mass, the Fe content is 5% by mass to 35% by mass, the Mn content is 1% by mass to 8% by mass, and the P ₂ O ₅ content is 0.00. It can be confirmed that by covering rice seeds with steelmaking slag having a composition of 1% by mass or more and 5% by mass or less, it is possible to obtain coated rice seeds with good growth at a lower cost than coating rice seeds with iron powder. It was. In iron-coated rice seeds, it became clear that, depending on the conditions, the growth of larvae was inhibited by the acidification accompanying iron hydroxide formation.

[Example 5] (long-term storage)
By the method described in Example 1, rice seeds coated with a steelmaking slag sample C having a maximum particle size of 600 μm whose composition is listed in Table 1 and control uncoated rice seeds were stored at room temperature in the dark. Covered rice seeds coated with sample C and dried for 3 hours at room temperature (0 days) and coated rice seeds stored for 1 month, 2 months, 3 months, 4 months, 5 months, 6 months The germination rate was investigated. For comparison, germination rates were also examined for uncoated rice seeds stored in the same environment. The germination rate is investigated by the following method.

  The germination test was performed when the storage period was 0 days, 1 month, 2 months, 3 months, 4 months, 5 months, and 6 months.

  Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. 20 coated rice seeds were placed on each filter paper soaked shallowly in distilled water. As a control, a petri dish was also prepared for uncoated rice seed that was not coated with steelmaking slag, and 20 grains were similarly placed on a filter paper soaked in distilled water. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated.

  FIG. 6 shows the results of the storage period and germination rate.

  Although the steelmaking slag sample C is alkaline, as a result of the germination test, it was found that the rice seeds coated with the sample C can germinate well even when stored for 6 months. Therefore, the coated rice seed of the present invention can be stored for a long time.

[Example 6] (Starch treatment)
Forty minutes of Koshihikari seeds were soaked in a solution in which starch was suspended in water so as to be 50% by mass. The seeds are removed from the starch suspension, the seeds are stirred in a suspension of sample C in which steelmaking slag sample C described in Example 1 is suspended in water at 66% by mass, and the seeds are coated with sample C. The coated seeds were removed and dried at room temperature for 24 hours. As a control, 40 rice seeds that were not soaked in the starch suspension were also seeded in the suspension of Sample C in which the steelmaking slag sample C described in Example 1 was suspended in water at 66% by mass. Stirring and seeds not subjected to starch treatment were prepared.

  Table 6 below shows the average value of the mass per seed obtained by coating the seed treated with starch and the seed not treated with starch with Sample C, and the average value of the mass of uncoated seed. Further, the amount of the coated substance was calculated by subtracting the mass of the uncoated seed from the mass of the rice seed coated with Sample C, and the results are shown in Table 6 together. Furthermore, the ratio of the amount of the coating substance to the mass of the uncoated seed was also shown.

  In the seeds that were not starch-treated, the ratio of the mass of the coating to the mass of the uncoated seed was 0.49, whereas in the seeds that were treated with starch, the ratio of the mass of the coating to the mass of the uncoated seed was It was possible to increase the adhesion amount of the coating.

  After covering with sample C, the rice seeds coated with starch-treated sample C and 20 rice seeds coated with non-starch-treated sample C, which were dried at room temperature for 24 hours, were placed on an iron plate from a position 20 cm in height. And let it fall naturally once. The rice seeds dropped on the iron plate were collected, and the mass was measured to determine the amount of coating substance per grain after dropping. The results (average values) are shown in Table 7 below.

  Further, the ratio of the amount of coating material after dropping to the amount of coating material before dropping was calculated and shown in Table 7 below.

  When the starch treatment was performed, the ratio of the coating material amount after dropping to the coating material amount before dropping was larger than that when the starch treatment was not performed. Therefore, it was found that the starch treatment increased the adherence of the coating and made it difficult for the coating to peel off.

  A germination test was conducted using the coated rice seeds that had been coated with Sample C and then dried at room temperature for 24 hours. Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in distilled water, 20 seeds of coated rice seeds that had been treated with starch and those that had not been treated with starch were placed. As a control, a petri dish was also prepared for uncoated rice seed that was not coated with steelmaking slag, and 20 grains were similarly placed on a filter paper soaked in distilled water. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. A germination test was similarly conducted using uncoated rice seeds as a control. Table 8 below shows the germination rate results.

  The coated rice seed treated with starch showed a high germination rate equivalent to the coated rice seed without starch treatment and the uncoated rice seed.

  Therefore, it was clarified that by covering the rice seed treated with starch with steelmaking slag, the mass of the coating can be increased and the germination rate can be maintained at a high value.

[Example 7] (Gypsum outer coating)
For 80 Koshihikari seeds, the seeds were stirred in a suspension of Sample C in which the steelmaking slag sample C described in Example 1 was suspended in water at 66% by mass, the seeds were coated with Sample C, and the coated seeds Was taken out and dried at room temperature for 24 hours. Out of the 80 seeds coated with Sample C, 40 grains were further coated with gypsum. The outer coating with gypsum was performed as follows.

  40 seeds coated with sample C were dipped into a suspension of gypsum in which hemihydrate gypsum was suspended in water at 30% by mass, quickly taken out, and dried at room temperature for another 24 hours. 40 seeds were further coated on the outside of the coating with gypsum.

  Table 9 below shows the average mass per grain of rice seeds coated only with sample C, rice seeds coated with sample C and coated with gypsum on the outside, and uncoated rice seeds. Moreover, the amount of the coating substance was calculated by subtracting the mass of the uncoated seed from the coated rice seed mass, and the results are shown in Table 9. Furthermore, the ratio of the amount of the coating substance to the mass of the uncoated seed was also shown.

  In the seed coated with sample C alone, the ratio of the mass of the coating to the mass of the uncoated seed was 0.54. However, in the seed coated with sample C and further coated with gypsum, The ratio of the mass of the coating to the mass was 0.93, and after coating with Sample C, the amount of adhesion could be increased by further coating with gypsum from the outside.

  20 rice seeds each coated with sample C and 20 rice seeds coated with sample C and coated with gypsum on the outside were naturally dropped once on an iron plate from a position of 20 cm in height. The rice seeds that fell on the iron plate were collected, the mass was measured, and the amount of coating substance per grain after the fall was examined. The results (average values) are shown in Table 10 below.

  In addition, the ratio of the amount of coating material after dropping to the amount of coating material before dropping was calculated and shown in Table 10 below.

  When the sample C was coated and the outside was further coated with gypsum, the ratio of the coating material amount after dropping to the coating material amount before dropping was a large value as compared with the case of coating only with the sample C. Therefore, it was found that by coating with steelmaking slag and further coating the outside with gypsum, the adhesion of the coating was increased and the coating was difficult to peel off.

  20 seeds each of rice seeds coated only with sample C and rice seeds further coated with gypsum after coating with sample C were used in the germination test. Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in this distilled water, 20 rice seeds each coated with only sample C and 20 rice seeds coated with gypsum after coating with sample C were placed. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. Table 11 below shows the germination rate results.

  Rice seeds coated with sample C and coated with gypsum on the outside showed a high germination rate of 80% or more, equivalent to rice seeds coated with sample C alone.

  Therefore, it was clarified that when the rice seeds were coated with steel slag and then the outside was coated with gypsum, the mass per grain of the coated rice seeds could be increased and the germination rate could be kept high.

Example 8 (Use of gypsum as additive)
Steelmaking slag sample C described in Example 1 and samples C to which gypsum was added at a mass ratio of 90% to 10%, 80% to 20%, and 50% to 50% were prepared. Sample C or sample C to which gypsum was added was suspended in water so that the ratio to water was 66% by mass. 40 koshihikari seeds were put into this suspension, stirred, and the seeds were taken out at room temperature. By drying for 24 hours, rice seeds coated with Sample C or Sample C with gypsum added at different ratios were produced.

  Table 12 below shows that per sample of rice seed coated with Sample C and Sample C with gypsum added at a mass ratio of 90% to 10%, 80% to 20%, 50% to 50%. Average mass is shown. The average mass per grain of uncoated rice seed is also shown. Further, the amount of the coated substance was calculated by subtracting the mass of the uncoated seed from the coated rice seed mass, and the results are shown in Table 12. Furthermore, the ratio of the amount of the coating substance to the mass of the uncoated seed was also shown.

  In the seed coated with sample C alone, the ratio of the mass of the coating to the mass of the uncoated seed was 0.49, but 90% to 10%, 80% to 20%, and 50% of gypsum were added to sample C. The ratio of the amount of the coating substance to the mass of the uncoated seed was almost the same in the seed coated with the material added at a mass ratio of 50%. Therefore, it can be seen that rice seeds can be coated using sample C with gypsum added at a mass ratio of 90% to 10%, 80% to 20%, and 50% to 50%.

  20 seeds each of rice seeds coated with the sample C and rice seeds coated with the sample C with gypsum added at a mass ratio of 90% to 10%, 80% to 20%, 50% to 50%. Then, it was naturally dropped once on the iron plate from a position of 20 cm in height. The seeds dropped on the iron plate were collected and weighed to examine the amount of coating material after dropping, and the ratio of the amount of coating material after dropping to the amount of coating material before dropping was calculated and shown in Table 13 below. It was.

  The amount of coating material before dropping when coated with sample C alone and when coated with a sample C with gypsum added at a mass ratio of 90% to 10%, 80% to 20%, 50% to 50% The ratio of the amount of coating material after falling to the same value was almost the same, and it was found that rice seed could be coated with steelmaking slag added with gypsum.

  After drying for 24 hours and confirming that all the coatings were solidified sufficiently, a germination test was conducted. Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in distilled water, 20 rice seeds coated with sample C alone and 20 rice seeds coated with sample C added with gypsum were placed. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. For comparison, a germination test using rice seeds not treated with starch and rice seeds treated with starch by the method described in Example 6 was performed in the same manner. Table 14 below shows the germination rate results.

  In the case where both the rice seed not treated with starch and the rice seed treated with starch are covered only with sample C, and when the ratio of the sample C to which gypsum is added is 80% to 20%, the germination rate is The germination rate was 80% or more, which was as high as the uncoated seed. On the other hand, the germination rate of the seeds coated with the material in which the ratio of the sample C to which gypsum was added was 50% to 50% was as low as 40% and 50%. Therefore, it is considered that 20% is appropriate as the upper limit of the addition ratio of gypsum to steelmaking slag when using a material obtained by adding gypsum to steelmaking slag for seed coating.

Example 9 (use of iron powder as additive)
Prepared steelmaking slag sample C described in Example 1, sample C with iron powder added by mass ratio of 80% to 20%, 50% to 50%, 20% to 80%, and iron powder did. Sample C, sample C to which iron powder is added, or iron powder, suspended in water so that the ratio to water is 66% by mass, and 20 koshihikari seeds are put in this suspension, Stirring, removing the seeds and drying at room temperature for 24 hours, rice seeds coated only with sample C, rice seeds coated with sample C added with iron powder, and rice seeds coated only with iron powder Produced. Similarly, for each of the 20 Koshihikari seeds taken from the starch suspension after immersing the Koshihikari seeds in a solution in which the starch is suspended in water so as to be 50% by mass, this sample C In sample C by adding iron powder to sample C or in a suspension of iron powder, stirring, removing the seeds and drying at room temperature for 24 hours. A coated starch-treated rice seed, a starch-treated rice seed coated with sample C added with iron powder, and a starch-treated rice seed coated with iron powder were prepared.

  Table 15 below shows rice seeds that were not starch-treated, rice seeds coated with sample C, and iron powder in sample C in proportions of 80% to 20%, 50% to 50%, and 20% to 80%. The average mass per grain was shown for rice seeds coated with those added in step 1 and rice seeds coated with iron powder. The average mass per uncoated rice seed is also shown. Further, the amount of the coated substance was calculated by subtracting the mass of the uncoated seed from the coated rice seed mass, and the results are shown in Table 15. Furthermore, the ratio of the amount of the coating substance to the mass of the uncoated seed was also shown.

  As shown in Table 15, since the specific gravity of iron powder is larger than that of steelmaking slag, the amount of coating substance tends to increase when the ratio of iron powder is large.

  In Table 16 below, for the seeds treated with starch, rice seed coated with sample C, and iron powder added to sample C at a mass ratio of 80% to 20%, 50% to 50%, 20% to 80% The average mass per grain was shown for the rice seeds coated with the rice seeds and the rice seeds coated with the iron powder. Further, the amount of the coated substance was calculated by subtracting the mass of the uncoated seed from the coated rice seed mass, and the results were also shown in Table 16. Furthermore, the ratio of the amount of the coating substance to the mass of the uncoated seed was also shown.

  In the seed treated with starch, the amount of the coating substance was larger than that in the case of the seed not treated with starch shown in Table 15. Therefore, it can be seen that by using the starch-treated seed, it is possible to produce not only steelmaking slag but also steelmaking slag added with iron powder or rice seed with more iron powder attached as a coating. .

  For rice seed not treated with starch, rice seed coated with sample C, iron powder added to sample C in a mass ratio of 80% to 20%, 50% to 50%, 20% to 80% Twenty grains of each of the coated rice seeds and the rice seeds coated with iron powder were naturally dropped once on the iron plate from a position of 20 cm in height. The seeds dropped on the iron plate were collected and weighed to examine the amount of coating material after dropping, and the ratio of the amount of coating material after dropping to the amount of coating material before dropping was calculated as shown in Table 17 below. It was.

  For seeds that have not been treated with starch, once the seeds are coated with steelmaking slag, the seeds are coated with steelmaking slag added with iron powder, and the seeds are coated with iron powder once. About 60% of the coating remained after falling on the iron plate. The smallest remaining amount of the coating was when the seed was coated with iron powder, and 55% remained.

  Starch-treated rice seeds were coated with rice seeds coated with sample C, and sample C was coated with iron powder added at a mass ratio of 80% to 20%, 50% to 50%, and 20% to 80%. 20 seeds each of rice seeds and rice seeds coated with iron powder were naturally dropped once on the iron plate from a position of 20 cm in height. The seeds dropped on the iron plate are collected and weighed to determine the amount of coating material after dropping, and the ratio of the amount of coating material after dropping to the amount of coating material before dropping is calculated as shown in Table 18 below. It was.

  In the seed treated with starch, compared to the seed not treated with starch shown in Table 17, when the seed is coated with steelmaking slag, when the seed is coated with steelmaking slag added with iron powder, and iron In all cases where the seeds were coated with the powder, the amount of the remaining coating increased with a single drop on the iron plate. By covering with steelmaking slag, it is possible to increase the adherence of the coating, whether it is coated with steelmaking slag added with iron powder, or coated with iron powder. Was found to be difficult to peel.

  Moreover, after drying for 24 hours and confirming that all the coatings were solidified sufficiently, the germination test was done.

  Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in distilled water, 20 rice seeds coated with only sample C and 20 rice seeds coated with sample C added with iron powder were placed. Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the seventh day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. Moreover, the length of the root was measured and the average length of the root was calculated. Further, the pH of water remaining in the petri dish was measured. For comparison, germination tests using uncoated rice seeds were also conducted.

  For comparison, a germination test using rice seeds not treated with starch and rice seeds treated with starch by the method described in Example 6 was performed in the same manner. Table 19 below shows the results of germination rate, average root length, and residual water pH.

  It was confirmed that in both cases, the germination rate was 80% or more for the rice seed not treated with starch and the rice seed treated with starch. However, when the mass ratio of the iron powder of the coating is 80% and only the iron powder, the average length of the roots is 34 mm and 26 mm for rice seeds not treated with starch, and 38 mm and 30 mm for rice seeds treated with starch. It was clearly shortened and suppression of root growth was observed. In the case where the mass ratio of iron powder in the coating is 80% and in the case of coating only with iron powder, the pH of the residual water is 4.4, 3.8 for the rice seed not treated with starch, It was acidified to 4.3 and 3.7. When iron powder is present, the eluted divalent iron ions are oxidized into trivalent iron ions by the action of microorganisms such as oxygen in the air and iron-oxidizing bacteria, and the trivalent iron ions are in a chemical form like ferric hydroxide. It is thought that it acidified by precipitating. When the ratio of the iron powder of the seed coating is high, it is considered that the growth of roots is suppressed by acidifying the water around the seeds. On the other hand, in the case of the mass ratio of steelmaking slag 80% to iron powder 20%, 50% to 50%, the root growth is good and the pH of the residual water is considered to be suitable for root growth from neutral to weakly acidic. there were. This is considered that the neutralization effect by the alkalinity of steelmaking slag was exhibited with respect to the acidification resulting from iron powder.

  Therefore, although iron powder can be mixed and used as an additive to steelmaking slag, the mass ratio of iron powder added to steelmaking slag is considered to be 50% by mass or less.

[Example 10] (Use of water containing molasses 1) (sedimentation, disintegration in water)
Using the steelmaking slag of Sample C whose composition is shown in Table 1, one prepared by sieving to a maximum particle size of less than 600 μm was prepared. Moreover, the water which melt | dissolved waste molasses in the pure water was prepared so that the mass ratio of molasses might be 5 mass%, 10 mass%, 25 mass%, 50 mass%, and 75 mass%. As a control, pure water not containing molasses (the mass ratio of molasses was 0% by mass) was also prepared.

  Using water containing molasses at each mass ratio as described above, water was added and mixed so that the mass ratio of water in the mixture of sample C and water was 30 mass%.

  Rice seeds (variety: “Koshihikari”) were added to the mixture of Sample C and water and mixed, and the rice seeds were covered with Sample C. Thereafter, the coated rice seeds were dried at room temperature for 24 hours in a well-ventilated state.

  Table 20 below shows the mass of the coated material when the mass before coating of the rice seeds coated with the mixture of Sample C and water having different mass ratios of molasses is 1.

  As is clear from Table 20 above, when the mass ratio of the molasses in the water containing molasses is 10%, 25%, and 50%, the coating when the mass of the rice seed before coating is 1 Thus, it can be seen that the mass of the coated rice seeds was greatly increased from that of the original rice seeds by the coating of the sample C, which was a steelmaking slag. By increasing the mass of the coated rice seeds, it can be expected to prevent the directly seeded coated rice seeds from floating in the paddy fields and running away.

  When the mass percentage of molasses in the water containing molasses was 75%, when this water was added to Sample C, Sample C became fooled and could not coat rice seeds (in the table) (Indicated by x.)

  Next, a container containing a sodium chloride aqueous solution (specific gravity 1.4) was prepared, and it was examined whether or not the coated rice seeds produced using water having different mass ratios of waste molasses settled. Further, the container for which the sedimentation property was examined was gently shaken for 1 hour (10 rpm), and the sedimentation property after 1 hour was also examined. The results obtained are shown in Table 21 below.

  As is apparent from Table 21, the coated rice seeds produced using water containing no molasses or water containing 5% by mass of molasses showed sedimentation immediately after the start of the test. However, when it was shaken gently for 1 hour, the coating was partially peeled and collapsed, and as a result, no sedimentation was shown. This result suggests that in the water with the flow, the covering of the rice-coated seed may partly peel and the seed may float and run away. However, in actual direct seeding of coated rice seeds, the seeds of the coated rice seeds are sowed on moist paddy soil exposed to the atmosphere, not in water, so it is considered that there is almost no fear of runoff due to running water as in this test.

  On the other hand, in coated rice seeds produced using water containing 10%, 25%, or 50% by weight of molasses, the covering hardly disappeared even after gently shaking for 1 hour. The sedimentation property was maintained.

  From the above results, in the coated rice seed produced using water containing 10% by mass to 50% by mass of molasses, the coating adhered to the seed in a stable manner, and even in flowing water It became clear that the coating was difficult to peel off and fall off.

[Example 11] (Use of water containing molasses 2) (germination test)
Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked in this distilled water, 10 coated rice seeds each coated with a steelmaking slag sample C produced using water having a different mass ratio of waste molasses in Example 10 were placed. Moreover, about the mixture which mixed iron powder and gypsum with a particle size of less than 600 by the mass ratio of 9: 1, the rice seed was added to what mixed and added 30 mass% of water which does not contain waste molasses to this mixture. The same applies to rice seeds coated with a mixture of iron powder and gypsum, dried for 24 hours in air at room temperature, and, as a control, rice seeds not coated with steelmaking slag. 10 pieces each were placed on a filter paper soaked in distilled water in a petri dish.

  When water with a mass ratio of molasses of 75% by mass was used, as shown in Example 10, this water was added to and mixed with Sample C, which is steelmaking slag. As a result, the rice seed could not be coated, and therefore the germination test could not be performed.

  Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the sixth day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. Moreover, about the germinated thing, the length and mass (fresh weight) of the radicle were measured, and the average radicle length (mm) and mass (fresh weight) per seed were calculated. The results obtained are shown in Table 22 below.

  As can be seen from Table 22, with respect to the germination rate, all the coated rice seeds tested showed the same germination rate as the uncoated seed.

  Regarding the average radicle length, when the mass ratio of molasses in the water used in the production of the coated rice seed is 5 mass%, 10 mass%, and 25 mass%, the average radicle length of the coated rice seed Was longer than the control uncoated rice seed. By using water containing molasses, it is considered that root elongation was further promoted by the effects of potassium and the like contained in the molasses. On the other hand, when coated with a mixture of iron powder and gypsum, the average radicle length is as follows: uncoated rice seed, coated rice seed from steelmaking slag sample C produced using water with different mass proportions of molasses It was clearly shorter than the average radicle length. When covered with a mixture of iron powder and gypsum, red rust adheres to the entire surface of the radicle, and it is considered that excessive iron hindered root elongation.

  Regarding the average radicle mass, the average radicle mass of the coated rice seeds coated with the mixture of iron powder and gypsum is the steelmaking slag sample C produced using water with different mass ratios of uncoated rice seed and molasses. The value was obviously smaller than the average radicle mass of the coated rice seed. Therefore, it became clear that the attachment of red rust covering the surface of the young root inhibited root growth not only in terms of root elongation but also in terms of mass.

  From the above results, it was clarified that the coated rice seed produced using water containing 5% by mass to 50% by mass of molasses has good germination rate and root growth.

  However, as shown in Example 10, in the coated rice seed produced using water containing 5% by mass of molasses, the coating is unstable in water, and the coating may be partially peeled off or dropped off. Therefore, more preferably, coated rice seed produced using water containing 10% by mass or more and 50% by mass or less of molasses is considered preferable.

[Example 12] (Use of water containing molasses 3) (Test using different types of steelmaking slag)
About five types of steelmaking slag samples A to E whose compositions are shown in Table 1, those prepared by sieving to a maximum particle size of less than 600 μm were prepared. Moreover, the water which melt | dissolved waste molasses in the pure water was prepared so that the mass ratio of waste molasses might be 25 mass%.

  Using water containing 25% by mass of waste molasses, water was added and mixed so that the mass ratio of the water in the mixture of each sample A to E and this water was 30% by mass.

  Rice seeds (variety: “Koshihikari”) were added to and mixed with each of the samples A to E and the water, and the rice seeds were covered with the samples A to E. Thereafter, the coated rice seeds were dried at room temperature for 24 hours in a well-ventilated state.

  Similarly, a mixture in which iron powder having a particle size of less than 600 and gypsum are mixed at a mass ratio of 9: 1 is prepared, and the mass ratio of pure water in the new mixture of this mixture and pure water is 30 mass%. Pure water was added to and mixed. Rice seeds (variety: “Koshihikari”) are mixed in this iron powder, gypsum and water mixture, and the rice seeds are coated with a mixture of iron powder and gypsum (iron powder: gypsum (9: 1)). did. Thereafter, the coated rice seeds were dried at room temperature for 24 hours in a well-ventilated state.

  Table 23 below shows the mass of the coated material when the mass before coating is 1 for the rice seeds coated with the steelmaking slag samples A to E or the mixture of iron powder and gypsum produced as described above. Shown in

  As is clear from Table 23 above, the amount of the coating substance per seed when the mass of the rice seed before coating was 1 was the largest when coated with a mixture of iron powder and gypsum. . This originates in the specific gravity of iron powder being larger than the specific gravity of steelmaking slag. However, even when covered with samples A to E, which are steelmaking slag, the amount of coating substance is 0.8 to 1.2 by producing coated rice seeds using water containing 25% by mass of molasses. there were. For example, compared with the case where the amount of the coating substance when coated with the sample C using water not containing molasses in Example 1 was 0.6, the coating with the sample C in this example was coated. The amount of substance is 0.9, and by using water containing 25% by mass of molasses, it can be seen that more steelmaking slag can be attached to rice seeds and the mass of coated rice seeds can be increased. .

  A germination test was performed using the coated rice seed produced as described above and the uncoated rice seed (variety: “Koshihikari”) as a control.

  Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. The coated rice seed coated with steelmaking slag samples A to E or a mixture of iron powder and gypsum (iron powder: gypsum (9: 1)) on filter paper soaked in distilled water is 10 Placed grains one by one.

  Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the fifth day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. Moreover, about what germinated, the length and mass (fresh weight) of the radicle were measured, and the average radicle length (mm) and mass (fresh weight) per seed were calculated. The results obtained are shown in Table 24 below.

  As can be seen from Table 24 above, no significant difference was observed in germination rate among all the seeds tested.

  Moreover, the coated rice seed coated with steelmaking slag samples A to E using water containing 25% by mass of molasses is more root than uncoated rice seed or rice seed coated with a mixture of iron powder and gypsum. The growth was good in both elongation and mass (fresh weight). In particular, the growth of roots was particularly good in rice seeds coated with Sample D using water containing 25% by mass of molasses. On the other hand, in the rice seed coated with the mixture of iron powder and gypsum, the root surface was covered with iron powder-derived red rust, and the growth of the root was inhibited, as in the result of Example 11.

Therefore, using water containing 25% by weight of molasses, 25% to 50% by weight of CaO, 8% to 30% by weight of SiO ₂ , and 1% to 20% by weight of MgO. Al ₂ O _{3 of} 1 to 25% by mass, Fe of 5 to 35% by mass, Mn of 1 to 8% by mass, 0.1 to 5% by mass The coated rice seeds coated with samples A to E, which are steelmaking slag containing the following P ₂ O ₅ , can be expected to germinate by direct sowing, and are uncoated rice seeds or a mixture of iron powder and gypsum. It became clear that the fertilizer effect which promotes root growth can be expected compared with the coated rice seed.

Example 13 (Use of water containing sodium alginate)
A steelmaking slag of Sample C whose composition is shown in Table 1 and sieved to a maximum particle size of less than 600 μm was prepared. Both were mixed so that the mass ratio of water in the mixture of Sample C and water was 30% by mass. Rice seeds (variety: “Koshihikari”) were mixed in the mixture of Sample C and water, and the rice seeds were covered with Sample C. The mass of the coating substance per seed was 0.6 when the mass of the rice seed before coating was 1. The rice seed coated with Sample C was air-dried for 3 hours in a well-ventilated state. In this state, the surface of the rice seed is only covered with the sample C which is steelmaking slag. The rice seeds coated with this sample C are divided into 6 groups, and one group is used as a coated rice seed that is left standing without doing anything, while the remaining 5 groups are 0.1% by mass and 0.5% by mass. %, 1%, 5%, and 10% by weight aqueous sodium alginate solution was sprayed to wet the surface of the coating. All six groups were air-dried for 24 hours with good ventilation.

  Prepare a container containing a sodium chloride aqueous solution (specific gravity 1.4), and spray onto the surface of the coated rice seeds and sodium alginate aqueous solution dried by spraying the sodium alginate aqueous solution of different concentration on the surface as described above. Each of the coated rice seeds was examined for settling. Further, the container for which the sedimentation property was examined was gently shaken for 1 hour (10 rpm), and the sedimentation property after 1 hour was also examined. The results obtained are shown in Table 25 below.

  As is apparent from Table 25 above, all the coated rice seeds tested exhibited sedimentation immediately after the start of the test. However, when gently shaking for 1 hour, a coated rice seed that did not spray the surface of the coating with an aqueous sodium alginate solution, and a coated rice seed that sprayed the surface of the coating with an aqueous 0.1% by weight sodium alginate solution, Was partially peeled off and disintegrated in the aqueous sodium chloride solution, and as a result, no sedimentation was observed. This suggests that, in a stream of water, part of the rice seed cover may be detached and the seed may float and run away. However, in actual direct seeding of coated rice seeds, the seeds of the coated rice seeds are sowed on moist paddy soil exposed to the atmosphere, not in water, so it is considered that there is almost no fear of runoff due to running water as in this test.

  On the other hand, in the coated rice seed sprayed with 0.5% by mass, 1% by mass, 5% by mass, and 10% by mass sodium alginate aqueous solution on the surface of the coating, the coating is hardly peeled off or dropped off, and gently for 1 hour. Sedimentation was maintained after shaking.

  From the above results, in the coated rice seeds sprayed with 0.5% by mass, 1% by mass, 5% by mass, and 10% by mass sodium alginate aqueous solution on the surface of the coating, the coating adhered to the seed stably and adhered. It was revealed that the coating was difficult to peel and drop even in flowing water.

  The coated rice seed coated with Sample C, which was surface-treated by spraying each concentration of sodium alginate aqueous solution on the surface of the coating, the coated rice seed not sprayed with the sodium alginate aqueous solution, and uncoated rice seed as a control ( Using the cultivar: “Koshihikari”), a germination test was conducted.

  Circular filter paper (11 cm in diameter) was laid on a plastic petri dish having an 11 cm diameter. Distilled water was added so that the filter paper was soaked shallowly in the distilled water. On the filter paper soaked shallowly in this distilled water, coated rice seeds sprayed onto the surface with different concentrations of sodium alginate aqueous solution and dried, and coated rice seeds that were not sprayed onto the surface of the sodium alginate aqueous solution, As a control, 10 uncoated rice seeds were placed.

  Each petri dish was placed in a thermostat at 30 ° C. with the top lid of the petri dish, and a germination test was performed. On the sixth day, the number of germination was measured for each petri dish of each sample, and the germination rate was calculated. For the germinated plants, the length and mass (fresh weight) of the radicles were measured, and the average radicle length (mm) and mass (fresh weight) per seed were calculated. The results obtained are shown in Table 26 below.

  As apparent from Table 26 above, with respect to the germination rate, in the coated rice seeds sprayed with a 10% by mass aqueous sodium alginate solution on the surface of the coating, the surface became hard and the germination rate was reduced.

  Regarding root growth, the coated rice seed sprayed with 0.1% by mass to 5% by mass sodium alginate aqueous solution on the surface of the coating had better root growth than the uncoated seed.

  Therefore, from the results of sedimentation and germination rate after 1 hour, it became clear that the coated rice seeds sprayed on the surface of the coating with a 0.5% by mass to 5% by mass aqueous sodium alginate solution were preferable.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

Claims (20)

A coated rice seed, wherein the rice seed is coated with a steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ . 25% by mass or more and 50% by mass or less of CaO, 8% by mass or more and 30% by mass or less of SiO ₂ , 1% by mass or more and 20% by mass or less of MgO, and 1% by mass or more and 25% by mass or less of Al ₂ O ₃ And a steelmaking slag containing 5% by mass or more and 35% by mass or less of Fe, 1% by mass or more and 8% by mass or less of Mn, and 0.1% by mass or more and 5% by mass or less of P ₂ O ₅ , Coated rice seeds that are coated with seeds.   A coated rice seed in which rice seed is coated with one or both of dephosphorization slag and decarburization slag, which are a type of steelmaking slag. Rice seed is coated with a mixture of steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ and one or both of gypsum and iron powder. The covered rice seeds. 25% by mass to 50% by mass of CaO, 8% by mass to 30% by mass of SiO ₂ , 1% by mass to 20% by mass of MgO, 1% by mass to 25% by mass of Al ₂ O ₃ , 5% by mass Steelmaking slag containing Fe of 1% to 35% by mass, Mn of 1% to 8% by mass, and P ₂ O ₅ of 0.1% to 5% by mass, gypsum, one of iron powder or Rice seed is coated with a mixture of both.   A coated rice seed in which rice seed is coated with a mixture of one or both of dephosphorization slag and decarburization slag, which is a kind of steelmaking slag, and one or both of gypsum and iron powder.   The coated rice seed according to any one of claims 1 to 6, wherein the rice seed is a rice seed coated with starch.   The coated rice seed according to any one of claims 1 to 7, wherein a surface of the coated rice seed is further coated with gypsum.   The coated rice seed according to any one of claims 1 to 8, wherein the coated portion of the coated rice seed further contains molasses. The rice seeds are coated with a mixture obtained by mixing steelmaking slag containing 25% by mass or more and 50% by mass or less of CaO and 8% by mass or more and 30% by mass or less of SiO ₂ with water, A method for producing coated rice seeds, wherein the mixture is consolidated. 25% by mass to 50% by mass of CaO, 8% by mass to 30% by mass of SiO ₂ , 1% by mass to 20% by mass of MgO, 1% by mass to 25% by mass of Al ₂ O ₃ , 5% by mass % To 35% by mass Fe, 1% by mass to 8% by mass Mn, and 0.1% by mass to 5% by mass P ₂ O ₅ steelmaking slag and water are mixed. A method for producing coated rice seeds, comprising coating rice seeds with the obtained mixture and solidifying the mixture.   Production of coated rice seed by coating rice seeds with a mixture obtained by mixing one or both of dephosphorization slag and decarburization slag, which is a type of steelmaking slag, and water, and solidifying the mixture. Method. It was obtained by mixing steelmaking slag containing CaO of 25% by mass or more and 50% by mass or less and SiO ₂ of 8% by mass or more and 30% by mass or less, water, and one or both of gypsum and iron powder. A method for producing coated rice seeds, comprising coating rice seeds with a mixture and solidifying the mixture. 25% by mass to 50% by mass of CaO, 8% by mass to 30% by mass of SiO ₂ , 1% by mass to 20% by mass of MgO, 1% by mass to 25% by mass of Al ₂ O ₃ , 5% by mass Steelmaking slag containing 1% or more and 35% by mass or less of Fe, 1% by mass or more and 8% by mass or less of Mn, and 0.1% by mass or more and 5% by mass or less of P ₂ O ₅ , water, gypsum, iron powder A method for producing coated rice seeds, comprising coating rice seeds with a mixture obtained by mixing one or both of the above and solidifying the mixture.   One kind of steelmaking slag, one or both of dephosphorization slag and decarburization slag, water and one or both of gypsum and iron powder are mixed with rice seed to cover the seeds. A method for producing coated rice seeds, wherein   The method for producing a coated rice seed according to any one of claims 10 to 15, wherein a mass ratio of water in the mixture is 10% by mass or more and 80% by mass or less with respect to a total mass of the mixture.   The method for producing a coated rice seed according to any one of claims 10 to 16, wherein the water is water containing 10% by mass to 50% by mass of waste molasses.   The method for producing a coated rice seed according to any one of claims 10 to 17, wherein a rice seed immersed in an aqueous starch solution is used as the rice seed.   The method for producing a coated rice seed according to any one of claims 10 to 18, wherein the surface of the consolidated mixture is further coated with gypsum. The surface of the solidified mixture is further moistened with water containing 0.5% by mass or more and 5% by mass or less of sodium alginate, and then the solidified mixture is dried. The manufacturing method of the coated rice seed of description.

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