JP6794846B2 - Covered seeds, method of producing covered seeds and method of sowing covered seeds - Google Patents

Description

The present invention relates to coated seeds, a method for producing coated seeds, and a method for sowing coated seeds.

With the aging of agricultural workers, it is important to save labor in agricultural work. For example, in paddy rice cultivation, a direct sowing method in which paddy rice seeds are sown directly in a paddy field is becoming widespread for the purpose of saving the trouble of raising seedlings and transplanting. At this time, if various plant seeds including paddy rice seeds are sown directly in the cultivated area, there is an increased possibility that the seeds will be eaten by the birds, causing bird damage. Therefore, in particular, for paddy rice seeds, an attempt has been made to prevent the floating and outflow of seeds and bird damage in paddy fields by coating the paddy rice seeds with iron powder (for example, Patent Document 1 below). See.).

Japanese Unexamined Patent Publication No. 2012-70728 Japanese Unexamined Patent Publication No. 2016-136861

However, when the seeds of plants such as paddy rice are coated with iron powder as disclosed in Patent Document 1, the metallic iron constituting the iron powder generates heat due to oxidation, which may impair the growth of the seeds. It turned out to be expensive. Further, since iron powder is a relatively expensive coating material, if a coating material containing iron powder as a main component as disclosed in Patent Document 1 is used, the material cost will increase.

Further, in Patent Document 1, the mass ratio of iron powder having a particle size of 63 μm or less is 0% or more and 75% or less, and the particle size is more than 63 μm and 150 μm or less with respect to the iron powder used for coating rice seeds. It is preferable that the mass ratio of iron powder is 25% or more and 100% or less, and the mass ratio of iron powder having a particle size of more than 150 μm is 0% or more and 50% or less. When water is added to iron powder having such a fine particle size, metallic iron dissolves and hydrates to iron hydroxide, and the seeds can be coated by forming dense iron rust. However, due to the high density, there are almost no voids between the iron powders, so that the coating acts as a barrier for oxygen and water to reach the seeds existing inside the coating from the outside of the coating. It ends up. As a result, there is concern that the supply of oxygen required for seed respiration and the supply of water required for germination will be insufficient. In particular, if an iron powder coating is applied to a plant cultivated in a non-flooded state, there is a concern that the water supply will be insufficient as compared with a plant cultivated in a flooded state.

Regarding this point, the above-mentioned Patent Document 2 which discloses the seed coating material discloses that slag is used as the seed coating material, and as an example of the slag, steel slag or steelmaking slag is mentioned. However, the only slag that has been specifically verified in Patent Document 2 is the slag obtained by melting and then cooling sewage sludge (sewage sludge molten slag), and the steel slag or steelmaking slag is specifically. No verification has been done.

Further, in Patent Document 2, a binder is used to coat the slag. According to the verification by the present inventors, even if the seeds are coated with powdered sewage sludge slag, the sewage sludge molten slag alone does not have the property of solidifying, and is disclosed in Patent Document 2 above. When the sludge is used as a seed coating material, it is necessary to use a substance having a solidifying property such as gypsum as a binder. The iron powder disclosed in Patent Document 1 and the like hardens itself by oxidation, so that the binder is not an essential component. However, in Patent Document 2, the binder is essential, so that the material cost Is worried about the rise.

Furthermore, in the sewage sludge molten slag used in Patent Document 2, there is a possibility that harmful heavy metals derived from sewage may be mixed, and there is a concern that harmful heavy metals may be absorbed and accumulated in germinated plants.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to suppress feeding damage by birds and animals to seeds of plants cultivated in a state of not being flooded, and further. It is an object of the present invention to provide a coated seed, a method for producing a coated seed, and a method for sowing the coated seed, which can be efficiently grown while reducing the cost.

As a result of diligent studies to solve the above problems, the present inventors have focused on the fact that the steelmaking slag produced as a by-product in the steelmaking process has a relatively low material cost and a fertilizer effect. The idea was to use such steelmaking slag to coat the seeds of plants cultivated without flooding, and the present invention was completed.
Plants cultivated in a non-flooded state are sown in a state where water is more likely to be insufficient than in a flooded plant, and water supply is particularly important at the time of germination. If it is coated with iron powder, the supply is likely to be insufficient due to the dense coating layer, but the layer coated with steelmaking slag has a large porosity, is easy to supply water, and can be expected to have a water retention effect in the pores.
The gist of the present invention completed based on the above findings is as follows.

(1) Surface of seeds of a plant cultivated in a non-flooded state containing a steelmaking slag containing at least 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. It has a coating layer coating the porosity of the coating layer is 17 to 50%, coated seeds.
( 2 ) The coated seed according to (1) , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 600 μm.
( 3 ) The coated seed according to (1) or (2) , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm.
(4) the steelmaking slag, 1 to 20 mass% of MgO, 1% by mass or more and 25 mass% of _Al 2 _O 3, 5 wt% to 35 wt% or less of Fe, 1 wt% or more and 8 mass _2. Described in any one of (1) to ( 3 ), further comprising at least one selected from the group consisting of Mn of% or less and P ₂ O _{5 of} 0.1% by mass or more and 5% by mass or less. Coated seeds.
( 5 ) The coated seed according to any one of (1) to ( 4 ), wherein the steelmaking slag is at least one of derinsed slag and decarburized slag.
( 6 ) The coating layer according to any one of (1) to ( 5 ), further comprising at least one selected from the group consisting of coal ash, gypsum, iron powder, cement, and molasses. Coated seeds.
( 7 ) The coated seed according to any one of (1) to ( 6 ), wherein the seed of the plant cultivated in a non-flooded state is a seed of a gramineous plant.
( 8 ) The seed of the plant cultivated in a non-flooded state is any one of (1) to ( 6 ), which is a seed of a legume, a Polygonaceae plant, an edible herbaceous plant, or a useful plant. The coated seeds described in.
( 9 ) The coated seed according to ( 7 ), wherein the seed of the Gramineae plant is upland rice seed, corn seed, or wheat seed.
( 10 ) The seeds of the legume family are soybean seeds or azuki seeds, the seeds of the tadashi family plant are buckwheat seeds, and the seeds of the edible herbaceous plant are carrot seeds, tomato seeds, or The coated seed according to ( 8 ), which is a vineyard seed, and the seed of the useful plant is a turf seed, a grass seed, a plant seed for green fertilizer, or a flowering tree seed.
( 11 ) The coated seed according to any one of (1) to ( 10 ), wherein the coating layer further contains an alginic acid compound.
( 12 ) The coated seed according to any one of (1) to ( 11 ), wherein the seed is a starch-coated seed.
( 13 ) Filled with a mixture obtained by mixing steelmaking slag containing at least 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 water. A method for producing coated seeds , wherein the seeds of a plant cultivated in a water-free state are coated , the particle size of the steelmaking slag is adjusted, and the porosity of the coating layer formed by the mixture is 17 to 50%. ..
( 14 ) The method for producing coated seeds according to ( 13 ), wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 600 μm.
( 15 ) The method for producing coated seeds according to ( 13 ) or ( 14 ), wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm.
( 16 ) The coated seed according to any one of ( 13 ) to ( 15 ), wherein the ratio of the water in the mixture is 10% by mass or more and 80% by mass or less with respect to the total mass of the mixture. Production method.
( 17 ) The coated seed according to any one of ( 13 ) to ( 16 ), wherein the mixture further comprises at least one selected from the group consisting of coal ash, gypsum, iron powder, and cement. Production method.
( 18 ) The method for producing coated seeds according to any one of ( 13 ) to ( 17 ), wherein the water is water containing 10% by mass or more and 50% by mass or less of molasses.
( 19 ) A method for sowing coated seeds, wherein the coated seed according to any one of (1) to ( 12 ) is directly sown in the cultivation area for cultivating the seed.

As described above, according to the present invention, it is possible to efficiently grow seeds of plants cultivated in a non-flooded state while suppressing feeding damage by birds and animals and further reducing costs. ..

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

(About coated seeds)
First, the coated seeds according to the embodiment of the present invention will be described in detail.
The coated seed according to the present embodiment contains a steelmaking slag containing a predetermined component and has a coating layer that covers the surface of the seed of a plant cultivated in a non-flooded state.

<About seeds>
In the following, first, the seeds used for the coated seeds according to the present embodiment will be briefly described.
In the coated seeds according to the present embodiment, seeds of plants cultivated in a non-flooded state are used. Here, "seed cultivated without being flooded" means a seed cultivated without being flooded and the surface of the soil is submerged in water.

Examples of seeds of plants cultivated in a non-flooded state include grass seeds, buckwheat seeds, buckwheat seeds, edible plant seeds, and useful plant seeds. Can be done.

The seeds of gramineous plants as described above are not particularly limited as long as they are cultivated on land that is not flooded, and any known grasses of gramineous plants can be used. Among the seeds of gramineous plants cultivated on land that are not flooded, for example, upland rice seeds, corn seeds, wheat seeds and the like can be mentioned.

The seeds of the above-mentioned legumes are not particularly limited as long as they are cultivated on land that is not flooded, and any known legume seeds can be used. Among the seeds of legumes cultivated on land that are not flooded, for example, soybean seeds, adzuki bean seeds and the like can be mentioned.

The seeds of the Polygonaceae plant as described above are not particularly limited as long as they are cultivated on land that is not flooded, and any known Polygonaceae plant seed can be used. Among the seeds of Polygonaceae plants cultivated on land that are not flooded, for example, buckwheat seeds and the like can be mentioned.

The seeds of the above-mentioned edible herbaceous plants are not particularly limited as long as they are the seeds of edible herbaceous plants (so-called vegetables) cultivated on land that is not flooded, and known seeds of edible herbaceous plants should be used. Is possible. Among the seeds of edible plants and plants cultivated on land that are not flooded, for example, carrot seeds, tomato seeds, sugar beet seeds and the like can be mentioned.

The seeds of useful plants as described above are not particularly limited as long as they are cultivated on land that is not flooded, and known useful plant seeds can be used. Among the seeds of useful plants cultivated on land that are not flooded, for example, turf seeds, grass seeds, plant seeds for green manure, flowering tree seeds and the like can be mentioned. Of these, the green manure plant is a plant that is used as a fertilizer for crops to be cultivated later by cultivating the cultivated plant as it is without harvesting it into the soil. Examples of such green manure plants include sorghum and the like.

In addition, bristles may be present on the surface of various seeds as described above. The presence of bristles on the surface of the seed can lead to a phenomenon in which the adhesion between the coating layer and the seed is weakened, as described in detail below. In order to suppress the possibility of such a phenomenon occurring, the surface of the seeds may be covered with starch by immersing various seeds as described above in an aqueous starch solution. This makes it possible to improve the adhesion between the coating layer and the seed, which will be described later. The concentration of the starch aqueous solution in which the various seeds are immersed as described above (that is, the mass ratio of starch to the total mass of the aqueous solution) is not particularly specified, but is, for example, 40% by mass to 80% by mass. Is preferable. By immersing the various seeds as described above in the starch aqueous solution having such a concentration, it is possible to more reliably improve the adhesion between the coating layer and the seeds.

The seeds applicable to the coated seeds according to the present embodiment have been briefly described above.

<About the coating layer>
Subsequently, the coating layer formed on the surface of the seed as described above will be described in detail.
The coating layer according to the present embodiment formed on the surface of seeds as described above contains steelmaking slag having a predetermined component. Hereinafter, the steelmaking slag contained in the coating layer will be described in detail.

[About steelmaking slag]
Steelmaking slag produced as a by-product in the steelmaking process has been analyzed and controlled in its composition and contains various fertilizer effective elements such as Ca, Si, Mg, Mn, Fe, and P. Therefore, it has been conventionally used as a fertilizer raw material. It is used. In Japan, as fertilizers made from steelmaking slag, there are fertilizers that belong to the standards of ore siliceous fertilizer, ore phosphate fertilizer, by-product lime fertilizer, and special fertilizer (iron-containing) specified by the Fertilizer Control Law. .. In addition, since steelmaking slag of about 10 million tons is produced annually in Japan alone, steelmaking slag can be obtained at low cost and material cost can be suppressed. Therefore, paddy rice seeds are coated with such steelmaking slag. Also in the coated seeds according to the present embodiment, steelmaking slag is used as the main component of the coating layer that covers the surfaces of various seeds as described above.

Steelmaking slag contains iron, but most of it is already oxidized iron oxide. Therefore, it is not necessary to consider the damage to the seeds due to the heat generated by the oxidation of iron, which is a concern in the seed coating with iron powder as in Patent Document 1. Further, the steelmaking slag has a property of solidifying. The porosity between the steelmaking slag particles is much larger than the porosity between the consolidated iron powder particles even in the consolidated state. Due to the large void ratio in the solidified state, in seeds coated with steelmaking slag, oxygen and water required for seed germination and growth are released from the outside of the coating layer as compared with seeds coated with iron powder. It is possible to reach the seeds inside the coating layer more easily.

Seed coating with steelmaking slag can also be applied to the seeds of plants cultivated in a non-flooded state, which is the focus of this embodiment. Regarding the germination of seeds, in the case of directly sown seeds that germinate without being flooded, it is important that water infiltrates the inside of the coating layer and the coating layer itself has a water retention capacity. The coating with steelmaking slag has a large void ratio between the steelmaking slag particles and has a higher water retention capacity than the iron powder coating, so that it is also suitable for germination of seeds cultivated under non-flooded conditions. Therefore, the coating with iron powder as disclosed in Patent Document 1 is mainly limited to rice seeds cultivated in a flooded state (that is, paddy rice seeds), whereas the coating with steelmaking slag is used. Is also applicable to the direct sowing of seeds of any plant grown without flooding.

The steelmaking slag used as the main component of the coating layer according to the present embodiment is a steelmaking slag containing at least 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. ..

◇ CaO: 25% by mass to 50% by mass
First, Ca will be described.
When the steelmaking slag comes into contact with water, Ca and Si or Al, which will be described later, are eluted and chemically bonded to each other to exhibit hydraulic slag. The present invention utilizes this hydraulic property to attach and consolidate steelmaking slag to various seeds to coat various seeds. Therefore, in the present invention, Ca is an important element. Ca is also an essential fertilizer element for plants. When the Ca content of fertilizer or steelmaking slag is expressed, the content is expressed in terms of oxide CaO. Therefore, the Ca content is hereinafter referred to as CaO.

In the present embodiment, when the CaO content of the steelmaking slag used for coating various seeds is less than 25% by mass, it is possible that a sufficient amount of Ca cannot be eluted to develop hydraulic slag. On the other hand, steelmaking slag having a CaO content of more than 50% by mass is not produced by a normal steelmaking process and is difficult to obtain. In the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Therefore, in the present embodiment, the CaO content of the steelmaking slag used for coating various seeds is 25% by mass or more and 50% by mass or less. The CaO content of the steelmaking slag is preferably 38% by mass or more and 50% by mass or less.

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

◇ SiO ₂ : 8% by mass to 30% by mass
Subsequently, Si will be described.
Si, along with Ca and Al, is an element that contributes to the hydraulic limeness of steelmaking slag. Therefore, Si is also an important element in the present invention. Although Si is not an essential element of plants, it is a very important fertilizer effect element especially for rice seeds such as upland rice. Silicic acid (SiO ₂ ) accounts for about 5% of the dry weight of rice plants. In fertilizers and steelmaking slags, when the Si content is expressed, the content is expressed in terms of the oxide SiO ₂ , so the Si content is hereinafter referred to as SiO ₂ .

In the present embodiment, when the content of SiO ₂ of the steelmaking slag used for coating various seeds is less than 8% by mass, it may not be possible to elute a sufficient amount of Si to develop hydraulic slag. .. 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 the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Therefore, in the present embodiment, the content of SiO ₂ of the steelmaking slag used for coating various seeds is 8% by mass or more and 30% by mass or less. The content of SiO _{2 in} the steelmaking slag is preferably 12% by mass or more and 25% by mass or less.

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

Since the CaO content of such steelmaking slag is 25% by mass or more and 50% by mass or less, it exhibits alkalinity of about pH 11. Therefore, when birds and beasts contain seeds having a coating layer containing such steelmaking slag in their mouths, the birds and beasts spit out the seeds without swallowing due to the alkalinity of the steelmaking slag. As a result, it becomes possible to suppress feeding damage caused by birds and beasts.

In addition, the seeds coated with such steelmaking slag germinate even though the steelmaking slag is alkaline. The reason why seeds germinate despite being alkaline is that acidic substances capable of chelating iron ions are secreted from the roots, and the alkali caused by the steelmaking slag that covered the seeds is neutralized, resulting in normal germination. It is believed that it is possible. Further, it is considered that the secretion of such an acidic substance causes iron contained in the steelmaking slag to be chelated as iron ions and easily absorbed from the radicles.

● Steelmaking slag containing a predetermined component The steelmaking slag contained in the coating layer according to the present embodiment is a steelmaking slag containing a predetermined component containing the following components in addition to the above CaO and SiO _2. You may. In other words, steel slag according to the present embodiment, the CaO and in addition to SiO _2, 1 to 20 mass% of MgO, 1% by mass or more and 25 mass% of _Al 2 _O 3, 5 wt% or more 35 mass% of Fe, 1 wt% or more and 8 mass% or less of Mn, and, further contain at least one selected from the group consisting of _P 2 _{O 5} of 5% by weight or less than 0.1 wt% May be good.

◇ MgO: 1% by mass to 20% by mass
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. The Mg contained in the steelmaking slag is mainly due to the Mg eluted from the refractory bricks in the furnace wall of the converter. Mg, together with Ca, Si and Al, is an element related to the hydraulic limeness of steelmaking slag. However, the contribution of Mg to hydraulic lime, such as the difference between the CaO content and the MgO content contained in the steelmaking slag, is smaller than that of Ca. In the present embodiment, since the steelmaking slag used for coating various seeds contains 25% by mass or more of CaO, it is considered that the hydraulic slag can be basically covered by the CaO contained in the steelmaking slag. However, the presence of MgO can be expected to better exhibit hydraulic limeness. In fertilizers and steelmaking slags, when the Mg content is expressed, the content is expressed in terms of the oxide MgO, so the Mg content is hereinafter referred to as MgO.

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

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

◇ Al ₂ O ₃ : 1% by mass to 25% by mass
Subsequently, Al will be described.
Al, along with Ca and Si, is an important element for the hydraulic limeness of steelmaking slag. In fertilizers and steelmaking slags, when the Al content is expressed, the content is expressed in terms of the oxide Al ₂ O ₃ , so the Al content is hereinafter referred to as Al ₂ O ₃ .

Steelmaking slag having an Al ₂ O ₃ content of less than 1% by mass and steelmaking slag having an Al ₂ O ₃ content of more than 25% by mass are not produced by a normal steelmaking process and are difficult to obtain. is there. In the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Further, if the content of Al ₂ O _{3 in} the steelmaking slag is 1% by mass or more, Al can exhibit hydraulicity together with Ca and Si. Therefore, in the present embodiment, the Al ₂ O ₃ content of the steelmaking slag used for coating various seeds is preferably 1% by mass or more and 25% by mass or less. However, when it is desired to further increase the hydraulic hardness and promote the solidification, in the present embodiment, the content of Al ₂ O ₃ of the steelmaking slag used for coating various seeds is set to 10% by mass or more and 25% by mass or less. It is more preferable to do so.

The content of Al ₂ O ₃ can be measured by, for example, a fluorescent X-ray analysis method.

◇ Fe: 5% by mass to 35% by mass
Subsequently, Fe will be described.
Fe is an element unavoidably contained in steelmaking slag. However, although steelmaking slag contains iron, most of it is already oxidized iron oxide and contains almost no metallic iron. Fe is not an essential element of plants, but iron is also an effective element for plants, just as the special fertilizers stipulated by the Fertilizer Control Law contain iron. Steelmaking slags having a Fe content of less than 5% by mass and steelmaking slags having a Fe content of more than 35% by mass are not produced by a normal ironmaking process and are difficult to obtain. In the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Therefore, in the present embodiment, the Fe content of the steelmaking slag used for coating various seeds is preferably 5% by mass or more and 35% by mass or less. The Fe content of 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, a fluorescent X-ray analysis method.

◇ Mn: 1% by mass to 8% by mass
Next, Mn will be described.
Mn is an element that has a fertilizing effect on plants. Steelmaking slag having a Mn content of less than 1% by mass and steelmaking slag having an Mn content of more than 8% by mass are not produced by a normal steelmaking process and are difficult to obtain. In the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Therefore, in the present embodiment, the Mn content of the steelmaking slag used for coating various seeds is preferably 1% by mass or more and 8% by mass or less.

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

◇ P ₂ O ₅ : 0.1% by mass to 5% by mass
Next, P will be described.
P is an essential element of the plant. The fertilizer and steel slag, when denoted the content of P, since the amount contained in terms of P ₂ O ₅ oxide is denoted, for steel slag used in the coating of various seeds in this embodiment Also represents the content as P ₂ O ₅ . P is an element that acts on the root growth point and has an effect on 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 the present embodiment, the steelmaking slag used for coating various seeds preferably can be stably supplied in a large amount, and is preferably produced by a normal steelmaking process. Accordingly, in the present embodiment, the content of P ₂ O ₅ of steel slag used in the coating of various seed is preferably 5 mass% or less than 0.1 wt%.

The content of P ₂ O ₅ can be measured by, for example, a fluorescent X-ray analysis method.

● Derinsing slag and decarburizing slag In the present embodiment, the steelmaking slag used for coating various seeds includes steelmaking slag containing a predetermined component as described above, as well as steelmaking produced as a by-product from the steelmaking process. It is also possible to use derinsed slag, decarburized slag, etc., which are a type of slag. Dephosphorus slag is a slag containing phosphorus that is produced as a by-product by adding lime, iron oxide, etc. as a dephosphorizing agent to the hot metal and blowing a gas such as oxygen in order to remove phosphorus contained in the hot metal. , A type of steelmaking slag. Further, the decarburized slag is a slag produced by blowing oxygen into the hot metal in order to remove carbon contained in the hot metal to make steel, and is a kind of steelmaking slag.

The derinsed slag and decarburized slag as described above also contain the same components as the steelmaking slag containing the above-mentioned predetermined amount of components, but the content is the same as the content of various components in the steelmaking slag. May be different. However, in the case of derinsed slag or decarburized slag, even if a component having a content different from that of the steelmaking slag containing the above-mentioned predetermined amount of the component is present, steelmaking for coating various seeds in the present embodiment. It can be used as a slag.

● Method for measuring the content of each component in steelmaking slag As described above, in the present embodiment, the content of each component in various steelmaking slags used for coating various seeds shall be measured by fluorescent X-ray analysis. Is possible. More specifically, a calibration curve is prepared 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 a sample whose content is unknown, the content of the component of interest can be specified by measuring the peak intensity of the fluorescent X-ray related to the component of interest and using a calibration curve prepared in advance. ..

The peak of the fluorescent X-ray of interest is not particularly limited, but for example, the fluorescent X-ray peak of Ca, Si, Mg, Al, Fe, Mn, and P may be focused on.

The method for measuring the content of each component in various steelmaking slags is not limited to the above-mentioned fluorescent X-ray analysis method, and other known analysis methods can be appropriately used.

● Particle size of steelmaking slag In the present embodiment, the above-mentioned steelmaking slag adjusted to a predetermined particle size by pulverization or the like can be used as it is for coating various seeds. For crushing these steelmaking 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 the present embodiment, the particle size of the steelmaking slag used for coating various seeds is more likely to solidify when the particle size is finer, so it is preferable to make the particle size finer than a predetermined value. As a result of the study by the present inventor, it has been clarified that the steelmaking slag having a particle size adjusted to less than 600 μm tends to have higher adhesion to various seeds and is highly effective. Therefore, it is preferable that the particle size of the steelmaking slag used as the main component of the coating layer according to the present embodiment is less than 600 μm. For example, steelmaking slag is sieved using a sieve having a pore size of 600 μm, and the particle size of the steelmaking slag that has passed through the mesh of the sieve is less than 600 μm. Steelmaking slag with a finer particle size is preferable for improving the adhesion to various seeds, but crushing and classification requires cost and time, so excessive miniaturization is not necessary.

In the present embodiment, the particle size of the steelmaking slag used for the coating layer is such that it passes through a sieve having a pore size of 180 μm and has a pore size of 22 μm in order to improve the adhesion to plant seeds cultivated under conditions that are not particularly flooded. It is more preferable that the material does not pass through the sieve. In other words, the particle size of the steelmaking slag used for the coating layer is more preferably 22 μm or more and less than 180 μm.

In the case of steelmaking slag that cannot pass through a sieve having a pore size of 180 μm, it may be difficult to cover the seeds because the adhesion to small-sized seeds among the plant seeds cultivated under the condition of not being flooded is deteriorated. On the other hand, steelmaking slag that passes through a sieve having a pore size of 22 μm has high adhesion to seeds, but increases the risk of dust being sucked into the respiratory organs of workers during seed coating. There is concern that dustproof measures will require costs. Further, there is a concern that the porosity between the steelmaking slag particles becomes small and becomes dense as in the case of iron powder coating, and the permeation of oxygen and water is suppressed. Therefore, it is preferable that the grain size of the steelmaking slag used for seed coating passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm.

When the particle size of the steelmaking slag constituting the coating layer is measured after the fact, the coating layer is peeled from the coated seeds having the coating layer, and the peeled coating layer is transferred to a scanning electron microscope or a transmission electron microscope. It may be measured by a known measuring device such as a microscope.

[About other components contained in the coating layer]
In addition to the steelmaking slag as described above, the coating layer according to the present embodiment further contains at least one selected from the group consisting of coal ash, gypsum, iron powder, cement, and molasses. May be good.

● Coal ash Coal ash (fly ash) is a type of ash produced when coal is burned, and is a substance containing SiO ₂ and Al ₂ O ₃ as main components. Common coal ash contains 40% by mass to 75% by mass of SiO ₂ , 15% by mass to 35% by mass of Al ₂ O ₃ , 2% by mass to 20% by mass of Fe ₂ O ₃ , and 1% by mass. In many cases, at least one of 10% by mass of CaO is contained so that the total is 100% by mass or less, and further, other components such as MgO may be contained. As is clear from such constituents, coal ash contains a component similar to that of steelmaking slag and is a substance that assists in solidification. By incorporating such coal ash into the coating layer, the coal ash functions as a binder, and the coating layer can be more reliably consolidated.

The coal ash contained in the coating layer is preferably coal ash that passes through a sieve having a pore size of 75 μm. In other words, the particle size of the coal ash contained in the coating layer is preferably less than 75 μm. By setting the particle size of the coal ash to less than 75 μm, the solidification rate of the coal ash can be increased, and the coating layer can be more easily consolidated. The smaller the particle size of the coal ash, the more preferable it is. However, since classification requires cost and time, it is not necessary to use excessively fine particles.

The content of coal ash that can be contained in the coating layer is preferably 20% by mass or less with respect to the mass of the steelmaking slag. If the ratio of coal ash to steelmaking slag exceeds 20% by mass, the ratio of coal ash is too high, which may reduce the degree of solidification and the germination rate of seeds.

● About gypsum and cement Gypsum and cement are substances that have solidifying properties and function as binders. Therefore, by incorporating at least one of such gypsum or cement in the coating layer, the coating layer can be more reliably consolidated.

Here, general cements are CaO of 62% by mass or more and 67% by mass or less, SiO _{2 of} 19% by mass or more and 24% by mass or less, MgO of 0.5% by mass or more and 3% by mass or less, and 2% by mass. At least one of Fe ₂ O _{3 of} % or more and 6% by mass or less and Al ₂ O _{3 of 2} % by mass or more and 7% by mass or less is contained so as to have a total of 100% by mass or less. There are many.

The content of gypsum or cement that can be contained in the coating layer is preferably 20% by mass or less with respect to the mass of the steelmaking slag. If the ratio of gypsum or cement to the steelmaking slag exceeds 20% by mass, the ratio of gypsum or cement is too high, which may reduce the germination rate of seeds.

The gypsum or cement as described above may be mixed with the coating layer, but it is also possible to coat the coating layer with gypsum or cement.

● About iron powder Iron powder is a substance with a large specific gravity. Therefore, by incorporating iron powder in the coating layer, it is possible to increase the weight of the coated seeds and make it difficult for the seeds to run off. The content of iron powder that can be contained in the coating layer is preferably 50% by mass or less with respect to the mass of the steelmaking slag. When the ratio of iron powder to steelmaking slag exceeds 50% by mass, there is a high possibility that the heat generated by the oxidation of metallic iron will increase the damage to the seeds, and the divalent iron ions eluted from the iron powder will be oxidized to trivalent. It becomes an iron ion and shows acidity when it precipitates as a hydroxide, which may adversely affect sprouting and slag growth. Moreover, since iron powder is expensive, a high proportion of iron powder is disadvantageous in terms of cost.

● Molasses Molasses is a dark brown liquid that is produced as a by-product when sugar is refined from squeezed juice such as sugar cane. It contains about 70 to 80% sugar, and also contains minerals and vitamins. In addition, molasses is a by-product and can be obtained at low cost. Molasses in particular contains about 2% of potassium necessary for plant cell growth. Potassium is absorbed from the roots of plants and is a necessary component for the growth of plant cells. Therefore, by including molasses in the coating layer, potassium derived from molasses can be supplied from the coating layer, and it can be expected that the growth of seedlings is further promoted. In addition, since molasses has adhesiveness, by incorporating molasses in the coating layer, it is possible to reinforce the solidification of the coating layer and the stability of adhesion to seeds, and the components contained in the molasses after germination. It is possible to promote the growth of radicles in addition to the fertilizer effect of steelmaking slag.

● Alginic acid compound The coating layer according to the present embodiment may contain a compound derived from alginic acid (alginic acid compound) such as sodium alginate, calcium alginate, magnesium alginate and the like.

Sodium alginate is a type of polysaccharide contained in algae such as brown algae. When Ca or Mg is added to an aqueous solution of sodium alginate, it has the property of gelling. Since steelmaking slag contains Ca and Mg, gelation occurs by adding an aqueous solution of sodium alginate to the surface of the steelmaking slag, which can reinforce the stability of adhesion of the coating layer containing steelmaking slag to seeds. It will be possible. In addition, when coated seeds prepared using sodium alginate are directly sown in soil, sodium alginate is decomposed by the action of soil microorganisms to become alginate oligosaccharides. Alginate oligosaccharides have the effect of assisting the absorption of minerals into plant roots by binding with minerals contained in the steelmaking slag of the coating layer, and can be expected to have the effect of promoting the growth of seedlings after germination.

The sodium alginate as described above may partially react with the calcium present in the steelmaking slag and may be present in the coating layer as calcium alginate. Similarly, if magnesium is present in the steelmaking slag, sodium alginate may partially react with magnesium in the steelmaking slag and be present in the coating layer as magnesium alginate. Therefore, when sodium alginate is contained in the coating layer according to the present embodiment, not only sodium alginate but also calcium alginate and magnesium alginate may be present in the coating layer. Similar to sodium alginate, these calcium alginate and magnesium alginate are also decomposed by the action of soil microorganisms to become alginate oligosaccharides. Alginate oligosaccharides have the effect of assisting the absorption of minerals into plant roots by binding with minerals contained in the steelmaking slag of the coating layer, and can be expected to have the effect of promoting the growth of seedlings after germination.

[About the porosity of the coating layer]
The porosity of the coating layer containing various steelmaking slags as described above is preferably 17 to 50%. The porosity of the coating layer can be controlled to a desired value by adjusting the particle size of the steelmaking slag contained in the coating layer, and the specific value of the porosity is appropriately set for the seed. It may be adjusted as appropriate. In order to preferably maintain oxygen supply and water retention, the porosity of the coating layer is preferably 20 to 40%, more preferably 20 to 30%.

The porosity of the coating layer can be measured as follows.
First, a seed having a coating layer is embedded in various resins and polished by a known method to prepare a measurement sample. Next, the cross section of the coating layer in the obtained measurement sample is observed with an optical microscope set to a predetermined magnification, and the area of pores occupying the area of the seed coating in the visual field is calculated and used as the porosity. .. The observation is carried out in a plurality of visual fields (for example, about 5 visual fields), and the average value of the porosity obtained in each visual field between the plurality of visual fields is obtained and used as the porosity of the covering layer.

The coating layer in the coated seed according to the present embodiment has been described in detail above.

<Regarding the components that can adhere to the surface of the coating layer>
At least one of a disinfectant, an insect repellent, and a herbicide may be attached to the surface of the coating layer according to the present embodiment. These chemicals adhering to the surface of the coating layer realize the medicinal effect of the corresponding chemicals on the soil in which the coated seeds are sown or the coated seeds themselves.

Here, the disinfectants that can adhere to the surface of the coating layer are thiuram, isothienyl, flametopyl, etaboxam, 2-[(2,5-dimethylphenoxy) methyl] -α-methoxy-N-methyl-benzeneacetamide, and benomyl. , Oxolinic acid, probenazole, thiazinyl, pyroquilon and diclosimet may be one or more selected from the group.

The insect repellent that can adhere to the surface of the coating layer is one or more selected from the group consisting of clothianidin, nitenpyram, benzultap, thiamethoxam, dinotefuran, pimetrodin, sulfoxaflor, benfracarb, carbosulfane and cartap hydrochloride. You may.

The herbicides that can adhere to the surface of the coating layer include amino acid compounds such as glyphosate and gluhosinate, carbamate compounds such as esprocarb, pyribuchicarb, benchocarb, and molinate, etobenzanide, cafentrol, tenylchlor, butacrol, pretilachlor, bromobutide, mephenacet, etc. Acid amide compounds, dinitroaniline compounds such as triflularin, azim sulfuron, imazosulfuron, ethoxysulfuron, cyclosulfamron, halosulfuron methyl, pyrazosulfuron ethyl, flucetosulfuron, propyrsulfone, benzulfuron methyl, thio Sulfonylurea compounds such as fensulfuronmethyl, sulfonanilide compounds such as pyrimisulfan, diazine compounds such as bentazone, diazole compounds such as oxadiazone, oxadialgyl, pyracronyl, pyrazoxifene, pyrazolate, pyraflufenethyl, benzophenap, etc. Triazine compounds such as dimetamethrin, simethrin, promethrin, triketone compounds such as tefryltrione and mesotrione, urea compounds such as cumyllon and dimulon, bipyridium compounds such as diquat and paracoat, bispyribac sodium salt, pyriminobacmethyl , Pyrimidyloxybenzoic acid compounds such as penoxyslam, phenoxy compounds such as 2,4-D, MCPA, xarohop, clomeprop, cihalohop, cihalohopbutyl, haloxyhop, clodinahop, isoxazole compounds such as isoxaflutol, imazetapill Imidazolinone compounds such as, organic phosphorus compounds such as butamiphos, aromatic carboxylic acid compounds such as dicamba, indanophan, oxadichromephone, calfentrazone ethyl, quinoclamin, pyriphthalide, fentrazamide, benzobicyclon, pentoxazone, and benfresate. It may be one or more selected from the group consisting of.

The above-mentioned compounds of the disinfectant, the insect repellent, and the herbicide are all known compounds, and commercially available preparations can be used, or they can be produced by a known production method.

In the present embodiment, the above-mentioned agent is usually a mixture of an active ingredient and an inert carrier, and if necessary, a surfactant or other formulation auxiliary agent is added to a powder, a flowable agent, or water. It is preferable to use those formulated in Japanese preparations, granule wettable powders, aqueous solvents, granular aqueous solvents and the like. Further, a preparation in which the elution of the active ingredient is controlled may be used.

Examples of the inert carrier used in the formulation include solid carriers and liquid carriers.
Examples of solid carriers include clays (kaolin dray, diatomaceous soil, bentonite, fubasami clay, acidic white clay, etc.), synthetic silicon hydroxide-containing talc, ceramics, and other inorganic minerals (serisite, quartz, sulfur, activated charcoal, calcium carbonate, water). Fine powders and granules such as Japanese silica), chemical fertilizers (sulfur-an, phosphorus-an, glass-an, urea, salt-an, etc.), and synthetic resins (polypropylene, polyacrylonitrile, polymethylmethacrylate, polyethylene terephthalate, etc.) , Nylon resin such as Nylon-6, Nylon-11, Nylon-66, Polyamide resin, Polyvinyl chloride, Polyvinylidene chloride, Vinyl chloride-propylene copolymer, etc.).
Examples of the liquid carrier include water, alcohols (methanol, ethanol, isopropyl alcohol, butanol, hexanol, benzyl alcohol, ethylene glycol, propylene glycol, phenoxyethanol, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.), and aromatics. Hydrocarbons (toluene, xylene, ethylbenzene, dodecylbenzene, phenylxysilyl ethane, methylnaphthalene, etc.), aliphatic hydrocarbons (hexane, cyclohexane, kerosene, light oil, etc.), esters (ethyl acetate, butyl acetate, myristic acid, etc.) Isopropyl, ethyl oleate, diisopropyl adipate, diisobutyl adipate, propylene glycol monomethyl ether acetate, etc.), nitriles (acetoyl, isobutyronitrile, etc.), ethers (diisopropyl ether, 1,4-dioxane, ethylene glycol dimethyl ether, etc.) Diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, etc.), acid amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.) ), Halogenized hydrocarbons (dioxide, trichloroethane, carbon tetrachloride, etc.), sulfoxides (dimethyl sulfoxide, etc.), propylene carbonate and vegetable oils (soybean oil, cottonseed oil, etc.).

Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers and polyethylene glycol fatty acid esters, and anions such as alkyl sulfonates, alkyl benzene sulfonates and alkyl sulfates. Surfactants can be mentioned.

Other pharmaceutical auxiliary agents include fixing agents, dispersants, coloring agents, stabilizers, etc., specifically casein, gelatin, sugars (temple, arabic gum, cellulose derivatives, alginic acid, etc.), lignin derivatives, bentonite, synthetic. Water-soluble polymers (polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acids, etc.), PAP (isopropyl acid phosphate), BHT (2,6-di-tert-butyl-4-methylphenol), BHA (2-tert-butyl) A mixture of -4-methoxyphenol and 3-tert-butyl-4-methoxyphenol) and the like.

At least a part of these disinfectants, insect repellents or herbicides may be present inside the coating layer. In addition, at least one of these disinfectants, insect repellents or herbicides may be contained in the coating layer.

The coated seeds according to the present embodiment have been described in detail above.

(About the manufacturing method of coated seeds)
Subsequently, a method for producing coated seeds according to the present embodiment will be described in detail using the steelmaking slag as described above.

In the method for producing coated seeds according to the present embodiment, the above-mentioned steelmaking slag containing at least 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 water. And, a mixture obtained by mixing and is prepared, and the seeds of a plant cultivated in a non-flooded state are coated with such a mixture.

Here, regarding the mixing ratio of water added to the steelmaking slag, the mass ratio of water in the mixture of the steelmaking slag and water (that is, the mass ratio of water to the total mass of the mixture) is 10% by mass or more and 80% by mass. % Or less is preferable. When the mass ratio of water in the mixture of the steelmaking slag and water is less than 10% by mass, the adhesion of the steelmaking slag to the seed surface is deteriorated, and there is a high possibility that coating becomes difficult. On the other hand, when the mass ratio of water in the mixture of the steelmaking slag and water exceeds 80% by mass, the proportion of water is too high, and there is a high possibility that the surface of the seed cannot be covered with the steelmaking slag. .. Therefore, the mass ratio of water in the mixture of the steelmaking slag and water is preferably 10% by mass or more and 80% by mass or less. In order to stably succeed in seed coating using steelmaking slag, it is more preferable that the mass ratio of water is 25% by mass or more and 50% by mass or less.

Further, at least one of coal ash, gypsum, iron powder, or cement may be mixed with the mixture of the steelmaking slag and water.

When at least any one of coal ash, gypsum or cement is added to the mixture, the mass ratio of each component to the steelmaking slag preferably does not exceed 20% by mass as mentioned above. When iron powder is added to the steelmaking slag, the mass ratio of the iron powder to the steelmaking slag preferably does not exceed 50% by mass as mentioned above.

Here, when the seed is coated with steelmaking slag or the like, as mentioned earlier, there is a possibility that the bristles existing on the seed surface weaken the adhesion of the coating layer to the seed surface. In order to solve this phenomenon, the seeds may be immersed in an aqueous starch solution in advance and then coated with steelmaking slag or the like. Here, the concentration of the starch aqueous 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 seeds in an aqueous starch solution, the seeds are coated with steelmaking slag or the like to increase the ratio of the mass of one seed to the mass of the coating layer to about 1: 0.6 to 1: 2. Is possible.

Next, a method of coating the seeds of a plant cultivated without being flooded with the above mixture will be described. By preparing a mixture as described above in advance and mixing this mixture with the seeds of a plant cultivated in an unflooded state, the surface of the seeds used is covered with steelmaking slag or the like, and the surface of the seeds is covered. Layers can be formed. It is also possible to coat the seeds with the steelmaking slag or the like by mixing the steelmaking slag or the like with water and seeds together. The method of mixing the mixture and the seed is not particularly limited. In the case of processing a large amount, for example, it is possible to mix using a rotary granulator and coat the seeds with the above-mentioned steelmaking slag or the like.

It is also possible to further coat the seeds on which the coating layer is formed by using steelmaking slag or the like with gypsum from the outside. By double-coating the seeds with steel-making slag and gypsum, it is possible to improve the adhesion to the seeds by coating the steel-making slag. As a method of coating the seeds on which the coating layer is formed with gypsum from the outside, for example, the coated seeds that have been coated with steelmaking slag or the like and dried are immersed in a water suspension of gypsum, taken out, and dried at room temperature. It can be done by using the method of letting. The concentration of the water suspension of gypsum is preferably, for example, 20% by mass to 60% by mass.

The amount of seeds covered with the above-mentioned steelmaking slag or the like is not particularly limited. More preferably, when the mass of the seed is 1, it is preferable to coat the seed with the above-mentioned steelmaking slag having a mass of about 0.1 to 2. Usually, the coating amount realized only by mixing seeds with a mixture of steelmaking slag or the like and water falls within the above range. However, when the surface of the seeds is not completely covered with the steelmaking slag or the like, it is preferable to mix the seeds with the mixture of the steelmaking slag and water again.

Further, in order to enhance the solidification of the steelmaking slag, either blast furnace slag fine powder or calcium sulfate is added to steelmaking slag or the like, a mixture of steelmaking slag or the like and water, or a mixture of steelmaking slag or the like and water and seeds. It is also effective to add to.

<About water used in the production of coated seeds>
Here, when the seeds are coated with a mixture of steelmaking slag or the like and water, the water is mixed with the steelmaking slag or the like, but in addition to pure water, tap water, groundwater, agricultural water or the like can also be used. Although possible, it is more preferable to use water containing waste sugar slag. By using water containing molasses, the stickiness of molasses can be used to reinforce the solidification of the coating layer and the stability of adhesion to seeds, and the components contained in molasses are the components of the slag after germination. Growth can be further promoted in addition to the fertilizer effect of steelmaking slag.

When the mass ratio of molasses contained in water containing molasses is less than 10% by mass with respect to the total mass, the effect of solidifying the coating layer made of steelmaking slag and reinforcing the adhesion stability to seeds is effective. , It becomes difficult to express clearly. On the other hand, when the mass ratio of molasses contained in the water containing molasses exceeds 50% by mass with respect to the total mass, when the steelmaking slag and the like and the water containing the molasses are mixed, the steelmaking slag Etc. become lumps and become difficult to adhere to the seeds. Therefore, the mass ratio of molasses contained in water containing molasses is preferably 10% by mass or more and 50% by mass or less with respect to the total mass.

<Surface treatment of coated seeds using an aqueous solution of sodium alginate>
As mentioned earlier, by adding an aqueous solution of sodium alginate to the surface of the coating layer containing steelmaking slag or the like, gelation occurs and the stability of adhesion of the coating layer containing steelmaking slag or the like to seeds can be reinforced. It will be possible.

A method for adding an aqueous solution of sodium alginate to the surface of a coating layer is, for example, a method of spraying or sprinkling an aqueous solution of sodium alginate on the surface of a coating layer containing steelmaking slag or the like. It is also possible to immerse the seeds having the coating layer containing steelmaking slag or the like in the sodium alginate aqueous solution for a short time while being careful not to peel off the coating layer. 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 sodium alginate is too low, so that gelation does not occur firmly and the coating layer is applied to the seeds. The effect of reinforcing the stability of adhesion may not be exhibited. Further, when the concentration of the sodium alginate aqueous solution exceeds 5% by mass with respect to the total mass of the aqueous solution, the gel becomes too strong and germination may be suppressed. Therefore, the concentration of the sodium alginate aqueous solution added to the surface of the coating layer containing steelmaking slag or the like is preferably 0.5% by mass or more and 5% by mass or less with respect to the total mass of the aqueous solution. The amount of the sodium alginate aqueous solution when the sodium alginate aqueous solution is sprayed or sprinkled may be an amount that moistens the entire surface of the coating layer.

<Surface treatment of coated seeds using disinfectants, insect repellents, and herbicides>
As mentioned earlier, it is possible to attach at least one of a disinfectant, an insect repellent, or a herbicide to the surface of the coating layer containing steelmaking slag and the like.

The method of adding the chemical to the surface of the coating layer is, for example, a method of spraying or sprinkling an aqueous solution containing the chemical on the surface of the coating layer containing steelmaking slag or the like. Further, for example, the chemical may be sprayed as it is on the surface of the coating layer containing steelmaking slag or the like, and the chemical may be adhered to the surface of the coating layer. The amount of the above-mentioned drug used for coated seeds is not particularly specified, but is preferably about 0 to 100 grams with respect to 1000 grams of dry weight of seeds, for example.

In the above description, the composition of the steelmaking slag and the like is shown as the composition before being mixed 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. As described above, the composition of the steelmaking slag before coating and the composition of the steelmaking slag after coating are almost the same.

Seeds coated with a coating layer containing steelmaking slag or the like can be used for direct sowing after being air-dried, for example, in a well-ventilated place. It is preferable to sow as soon as possible after the coating, because the coating deteriorates the air permeability and suppresses the respiration of the seeds. If possible, it is preferable to sow within 4 days after coating.

However, it is also possible to store the coated seeds and use them for direct sowing for up to about half a year after coating.

As described above, it is possible to easily and inexpensively produce coated seeds using steelmaking slag or the like.

(About sowing method of covered seeds)
Subsequently, the method of sowing the coated seeds as described above will be briefly described.
In the method of sowing coated seeds according to the present embodiment, the coated seeds as described above are directly sown in the cultivation area for cultivating the seeds.

Here, the sowing method of the coated seed is not particularly limited, and a known sowing method suitable for cultivation of the plant used for the coated seed may be adopted.

Hereinafter, the coated seeds, the method for producing the coated seeds, and the method for sowing the coated seeds according to the present invention will be specifically described with reference to Examples and Comparative Examples. The examples shown below are merely examples of the coated seeds, the method for producing coated seeds, and the method for sowing coated seeds according to the present invention, and the methods for producing coated seeds, coated seeds, and coated seeds according to the present invention. The sowing method is not limited to the following examples. The rice seeds in the examples shown below are upland rice seeds.

(Example 1)
The steelmaking slag having the composition shown in Table 1 below is crushed, and the crushed steelmaking slag is obtained from A (0 to 22 μm), B (22 μm to 180 μm), C (180 μm to 600 μm), using sieves having different pore sizes. It was classified into 4 types of D (600 μm to 2 mm). Rice seeds and corn seeds were coated with each of the steelmaking slags A to D.

More specifically, a mixture of steelmaking slag and water having the composition shown in Table 1 below was prepared, and the obtained mixture and rice seeds and corn seeds were mixed and applied to the surface of the rice seeds and corn seeds. , A mixture of steelmaking slag and water was attached. Then, the rice seeds and corn seeds to which the mixture was attached were dried to form a coating layer on the seed surface to obtain coated rice seeds and coated corn seeds.

When various seedlings were coated with steelmaking slag classified into D (600 μm to 2 mm), the formed coating layer had poor adhesion to seeds, and the coating layer was easily peeled off, so that a germination test was conducted. I couldn't. On the other hand, when various seedlings were coated with steelmaking slag classified into A to C, the adhesion of the formed coating layer to seeds was appropriate, and a germination test could be performed.

Spread filter paper on a 90 mm diameter plastic petri dish, place 20 rice seeds and 20 corn seeds covered with steelmaking slag on each petri dish, add distilled water, and let stand at 28 ° C for germination test. I did. At this time, the amount of distilled water added was adjusted so that the various children would not be flooded. As a control, the same germination test was conducted in parallel for uncoated rice seeds and corn seeds. Since the uncoated seeds were easy to dry, additional water was supplied, but the coated seeds were not additionally supplied with water. The results of the obtained germination test are shown in Table 2 below.

From the results of germination rate in Table 2, rice seeds and corn seeds coated with steelmaking slag classified into B (steelmaking slag that passes through a sieve with a pore size of 180 μm and does not pass through a sieve with a pore size of 22 μm) germinate most stably. It was found that the rate was high and the germination rate was almost the same as that of various uncoated seedlings.

Therefore, by coating with steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm, a stable germination rate can be obtained for any plant seed cultivated without being flooded. I understood.

(Example 2)
The steelmaking slag having the composition shown in Table 3 below is crushed, and the steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm is classified. Using the obtained steelmaking slag, rice seeds, And coated with corn seeds.

More specifically, a mixture of steelmaking slag and water having the composition shown in Table 3 below was prepared, and the obtained mixture and rice seeds and corn seeds were mixed and applied to the surface of the rice seeds and corn seeds. , A mixture of steelmaking slag and water was attached. Then, the rice seeds and corn seeds to which the mixture was attached were dried to form a coating layer on the seed surface to obtain coated rice seeds and coated corn seeds.

Fifty seeds of each coated seed were dispersed and arranged on a plastic plate, and the plastic plate was placed in the field under the condition of being covered with an enclosure so as not to be affected by the wind. After 2 weeks, the number of seeds remaining uneaten by birds was counted, and the seed survival rate was calculated. As a control, similar tests were performed in parallel for uncoated rice seeds and corn seeds. The results of the obtained residual rate are shown in Table 4 below.

As is clear from Table 4 above, it was found that both rice seeds and corn seeds coated with a coating layer containing steelmaking slag had a higher residual rate than uncoated seeds and could not be eaten by birds.

(Example 3)
Steelmaking slag having the composition shown in Table 1 is crushed, and the crushed steelmaking slag is classified using sieves having different pore diameters. Was used to coat rice seeds and slag seeds.

More specifically, a mixture of steelmaking slag of B (passing through a sieve having a pore size of 180 μm and not passing through a sieve having a pore size of 22 μm) and water containing 20% by mass of waste sugar was prepared, and the obtained mixture and Rice seeds and corn seeds were mixed, and a mixture of steelmaking slag, water and waste sugar slag was attached to the surface of the rice seeds and corn seeds. Then, the rice seeds and corn seeds to which the mixture was attached were dried to form a coating layer on the seed surface to obtain coated rice seeds and coated corn seeds.

Filter paper is laid on a 90 mm diameter plastic petri dish, and 20 rice seeds and corn seeds covered with B (passing through a sieve with a pore size of 180 μm and not passing through a sieve with a pore size of 22 μm) covered with steelmaking slag are placed on each petri dish. The seeds were placed, distilled water was added, and the mixture was allowed to stand at 28 ° C. for a germination test. At this time, the amount of distilled water added was adjusted so that the various children would not be flooded. As a control, the same germination test was conducted in parallel for uncoated rice seeds and corn seeds. Since the uncoated seeds were easy to dry, additional water was supplied, but the coated seeds were not additionally supplied with water. The results of the germination test obtained are shown in Table 5 below.

As is clear from Table 5 above, rice seeds and corn seeds coated with steelmaking slag of B (passing through a sieve having a pore size of 180 μm and not passing through a sieve having a pore size of 22 μm) germinate almost the same as various uncoated seedlings. It turns out that the rate can be obtained.

Therefore, by coating with steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm, a stable germination rate can be obtained for any plant seed cultivated without being flooded. I understood.

(Example 4)
50 grains of rice seeds and corn seeds coated with steelmaking slag of B (passing through a sieve having a pore size of 180 μm and not passing through a sieve having a pore size of 22 μm) prepared by the method described in Example 3 were dispersed in a plastic dish. It was placed and placed outdoors under the condition that the plastic plate was covered with an enclosure so as not to be affected by the wind. After 2 weeks, the number of seeds remaining uneaten by birds was counted, and the seed survival rate was calculated. As a control, similar tests were performed in parallel for uncoated rice seeds and corn seeds. The results of the obtained residual rate are shown in Table 6 below.

As is clear from Table 6 above, both rice seeds and corn seeds coated with steelmaking slag of B (passing through a sieve having a pore size of 180 μm and not passing through a sieve having a pore size of 22 μm) have a residual rate as compared with uncoated seeds. It turned out that it was too expensive for birds to eat.

(Example 5)
Steelmaking slag passing through a sieve having a pore size of 180 μm and iron powder (purity> 99%) whose compositions are shown in Table 1 were prepared. A mixture of steelmaking slag and water and a mixture of iron powder and water are mixed with corn seeds, and a mixture of steelmaking slag and water or a mixture of iron powder and water is applied to the surface of the corn seeds. It was attached. These corn seeds were dried to form a coating layer made of steelmaking slag or a coating layer made of iron powder on the seed surface.

The seeds coated with steelmaking slag or iron powder were embedded in the resin, polished, and then the cross section of the coating layer was observed with an optical microscope. The porosity of the coating layer made of steelmaking slag or the coating layer made of iron powder was determined with reference to the area of pores in the area of the covering observed in the cross section of the covering. The results obtained are shown in Table 7 below.

As is clear from Table 7 above, the porosity of the coating layer made of steelmaking slag was as high as 23%, whereas the porosity of the coating layer made of iron powder was as low as 1%. .. It was found that a dense coating layer was formed in the iron powder coating layer, and that there were almost no voids important as water and air supply channels for water supply and oxygen supply during germination. On the other hand, it was found that the coating layer made of steelmaking slag has sufficient voids that are important as water and air supply paths for water supply and oxygen supply.

A germination test was carried out using the above-mentioned corn seeds coated with steelmaking slag and corn seeds coated with iron powder.
More specifically, filter paper was laid on a 90 mm diameter plastic petri dish, and each petri dish was coated with corn seeds coated with steelmaking slag that had passed through a sieve having a pore size of 180 μm and iron powder that had passed through a sieve having a pore diameter of 180 μm. Twenty corn seeds were placed on each, distilled water was added, and the seeds were allowed to stand at 28 ° C. for a germination test. At this time, the amount of distilled water added was adjusted so that the seeds would not be flooded. The results of the germination test obtained are shown in Table 8 below.

As is clear from Table 8 above, the germination rate of corn seeds coated with iron powder was as low as 60%. It is considered that this is because the iron powder coating has a low porosity and a dense coating layer is formed, so that the supply of water and oxygen to the seeds is insufficient and germination is suppressed. On the other hand, the germination rate of corn seeds coated with steelmaking slag was as good as 85%. It is considered that this is because the porosity was as high as 23% when coated with steelmaking slag, and the supply of water and oxygen to the seeds was good.

Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such examples. It is clear that anyone with ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

Claims (19)

It contains steelmaking slag containing at least 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 covers the surface of seeds of plants cultivated in a non-flooded state. have a coating layer,
Coated seeds , the porosity of the coating layer is 17-50% . The coated seed according to claim 1 , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 600 μm. The coated seed according to claim 1 or 2 , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm. The steelmaking slag, 1 to 20 mass% of MgO, 1% by mass or more and 25 mass% of _Al 2 _O 3, 5 wt% to 35 wt% Fe, 1 wt% or more and 8 mass% or less The coated seed according to any one of claims 1 to 3 , further comprising at least one selected from the group consisting of Mn and P ₂ O _{5 of} 0.1% by mass or more and 5% by mass or less. The coated seed according to any one of claims 1 to 4 , wherein the steelmaking slag is at least one of derinsed slag and decarburized slag. The coated seed according to any one of claims 1 to 5 , wherein the coating layer further contains at least one selected from the group consisting of coal ash, gypsum, iron powder, cement, and molasses. The coated seed according to any one of claims 1 to 6 , wherein the seed of the plant cultivated in a non-flooded state is a seed of a gramineous plant. The coated seed according to any one of claims 1 to 6 , wherein the seed of the plant cultivated in a non-flooded state is a seed of a legume, a Polygonaceae plant, an edible herbaceous plant, or a useful plant. .. The coated seed according to claim 7 , wherein the seed of the grass family is upland rice seed, corn seed, or wheat seed. The seeds of the legumes are soybean seeds or adzuki bean seeds.
The seeds of the Polygonaceae plant are buckwheat seeds,
The seeds of the edible herbaceous plant are carrot seeds, tomato seeds, or sugar beet seeds.
The coated seed according to claim 8 , wherein the seed of the useful plant is a turf seed, a grass seed, a plant seed for green manure, or a flowering tree seed. The coated seed according to any one of claims 1 to 10 , wherein the coating layer further contains an alginic acid compound. The coated seed according to any one of claims 1 to 11 , wherein the seed is a seed coated with starch. A state in which water is not flooded by a mixture obtained by mixing steelmaking slag containing at least 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 water. seeds were coated for in plants cultivated,
A method for producing coated seeds , wherein the particle size of the steelmaking slag is adjusted so that the porosity of the coating layer formed by the mixture is 17 to 50% . The method for producing coated seeds according to claim 13 , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 600 μm. The method for producing coated seeds according to claim 13 or 14 , wherein the steelmaking slag is a steelmaking slag that passes through a sieve having a pore size of 180 μm and does not pass through a sieve having a pore size of 22 μm. The method for producing coated seeds according to any one of claims 13 to 15 , wherein the ratio of the water in the mixture is 10% by mass or more and 80% by mass or less with respect to the total mass of the mixture. The method for producing coated seeds according to any one of claims 13 to 16 , wherein the mixture further comprises at least one selected from the group consisting of coal ash, gypsum, iron powder, and cement. The method for producing coated seeds according to any one of claims 13 to 17 , wherein the water is water containing 10% by mass or more and 50% by mass or less of molasses. A method for sowing coated seeds, wherein the coated seed according to any one of claims 1 to 12 is directly sown in a cultivation area for cultivating the seed.