Growth promotion method and growth promoter

Abstract

Realizing technology to promote seed growth and reducing the labor required for seed preparation A method for promoting the growth of seeds includes a soaking step of soaking the seeds in a suspension containing a growth promoter including lime and silica.

Description

[Technical field]

[0001] The present invention relates to a method for promoting seed growth and a seed growth promoter. [Background technology]

[0002] In rice cultivation, a series of preparatory steps (seed preparations) are carried out before sowing to ensure good germination and subsequent growth. Specifically, it is necessary to prepare seeds in a slightly germinated state called pigeon breast through the processes of seed selection, disinfection, soaking, and germination. Methods of direct seed sowing are broadly divided into surface sowing, where seeds are sown on the soil surface, and subsurface sowing, where seeds are sown underground. Surface sowing is known to have problems with lodging and floating rice due to poor rooting, while subsurface sowing is known to have problems with reduced seedling establishment due to lack of oxygen.

[0003] In order to solve the problems that may arise when seeds are directly sown, the techniques of Patent Documents 1 to 3 describe a method of coating the surface of seeds with iron, calcium, or the like. Patent Documents 1 and 2 describe a technique of coating the surface of seeds with a material containing slag or incineration ash. Patent Document 3 describes direct sowing of seeds coated with a coating material containing iron powder. Also, a technique of coating seeds with a calcium peroxide agent is known to solve the problem of oxygen deficiency caused by sowing in soil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-136861 A [Patent Document 2] JP 2017-046674 A [Patent Document 3] JP 2023-110185 A Summary of the Invention [Problem to be solved by the invention]

[0005] Among the seed preparation steps, the soaking process, in which the seeds are soaked in temperature-controlled water to fully absorb the water, takes about a week and accounts for the majority of the work period. During the soaking process, the water needs to be changed every few days to prevent the seeds from becoming oxygen-deprived or rotting, which increases the time that agricultural workers are required to work, placing a burden on them.

[0006] In addition, the techniques of Patent Documents 1 to 3 and calcium peroxide coating technique require skilled techniques to properly coat the surface of the seeds. Furthermore, there is a method of preventing poor rooting and oxygen deficiency by rooting the seeds and sowing them in a shallow layer of the soil, but the rooting process takes about two days, which requires more time for agricultural workers than the seed soaking process.

[0007] One aspect of the present invention has been made to solve the above-mentioned problems, and its object is to realize a technology for promoting seed growth and, for example, to reduce the labor required for seed preparation work. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention includes, for example, the following aspects. (1) A method for promoting seed growth, comprising a soaking step of soaking the seeds in a suspension containing a growth promoter including calcium oxide (CaO) and silica (SiO2). (2) A growth promoter for rice seeds, containing steel slag. Effect of the Invention

[0009] According to one aspect of the present invention, a technique for promoting seed growth is realized, which can reduce the labor required for seed preparation, for example. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram comparing the germination of seeds soaked in a slag suspension in an example. [Diagram 2] FIG. 1 is a diagram comparing germination of seeds soaked in a slag suspension in an example. [Diagram 3] FIG. 1 is a diagram comparing root growth of seeds immersed in a slag suspension in an example. [Figure 4] FIG. 2 is a graph comparing the number of seeds that sprouted when immersed in a slag suspension for each sowing method in the examples. [Diagram 5] 1 is a graph comparing the number of seeds that germinate when soaked in a slag suspension in an example, by sowing method. [Figure 6] FIG. 2 is a diagram showing the particle size of slag used in the examples. [Figure 7] 1 is a graph showing the results of investigating the relationship between slug particle size and the number of germinated seeds and the average coleoptile length in an example. [Figure 8] FIG. 2 is a diagram showing the slag suspensions used in the examples by concentration. [Figure 9] 1 is a graph showing the results of investigating the relationship between the slag suspension concentration and the number of germinated seeds and the average coleoptile length in an example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Embodiment] Hereinafter, one embodiment of the present invention will be described in detail. A method for promoting seed growth according to one embodiment of the present invention is a method comprising a soaking step of soaking seeds in a suspension containing a growth promoter including calcium oxide (CaO) and silica (SiO2).

[0012] (Growth promoter) The seed growth promoter is not particularly limited as long as it contains calcium oxide (CaO) and silica (SiO2), but may further contain at least one element selected from the group consisting of magnesium, phosphorus, iron, manganese, and boron, and may more preferably contain at least two, three, four, or five (all) elements. Magnesium, phosphorus, iron, manganese, and boron may be contained as simple substances or in the form of compounds such as salts and oxides. For example, compounds such as magnesium oxide (MgO), diphosphorus pentoxide (PO5), iron oxide (FeO), iron(III) oxide (Fe2O3), manganese oxide (MnO), and boron oxide may be included.

[0013] The ratio of each component contained in the growth promoter is not particularly limited, but calcium oxide is, for example, in the range of 30% by mass or more and 50% by mass or less, 40% by mass or more and 50% by mass or less, and 42% by mass or more and 50% by mass or less. Silica is, for example, in the range of 5% by mass or more and 15% by mass or less, 5% by mass or more and 13% by mass or less, and 5% by mass or more and 12% by mass or less. When magnesium oxide (MgO) is contained, it is, for example, in the range of 1% by mass or more and 10% by mass or less, 1% by mass or more and 5% by mass or less, and 2% by mass or more and 5% by mass or less. When diphosphorus pentoxide (P2O5) is contained, it is, for example, in the range of 1% by mass or more and 10% by mass or less, 1% by mass or more and 5% by mass or less, and 2% by mass or more and 4% by mass or less. When iron (III) oxide (Fe2O3) is contained, the content is, for example, in the range of 5% by mass or more and 20% by mass or less, in the range of 5% by mass or more and 15% by mass or less, and in the range of 7% by mass or more and 15% by mass or less. When magnesium element, phosphorus element, and iron element are contained in a form other than MgO, P2O5, and Fe2O3, the content of these elements can be a value converted from the content of the above-mentioned specifically exemplified compounds. For example, the content of magnesium element can be a value obtained by multiplying the content (mass%) of magnesium oxide (MgO) by about 0.6. When manganese element is contained, the content is, for example, in the range of 1% by mass or more and 10% by mass or less, in the range of 1% by mass or more and 5% by mass or less, and in the range of 2% by mass or more and 4% by mass or less. When boron element is contained, the content is, for example, 1 g / kg or less, in the range of 50 mg / kg or more and 1 g / kg or less, and in the range of 100 mg / kg or more and 600 mg / kg or less.

[0014] The form of the growth promoter is not particularly limited, but may be, for example, a solid, particularly a granular or powdery solid, and is used in the form of a suspension suspended in water as described below. An example of the growth promoter is steel slag such as blast furnace slag or steelmaking slag. The steel slag may be used as is, or may be selected from those having a particle size within a predetermined range using a sieve or the like, or may be used as a powder having a smaller particle size by crushing or the like, or these may be used in combination. When the steel slag is made into a powder having a smaller particle size by crushing or the like, it may be easier to suspend it in water, or the effect of the growth promoter may be more easily exerted. The powder of the steel slag may be, for example, preferably a powder having a particle size of 200 μm or less, preferably a powder having a particle size of 100 μm or less, or preferably a powder having a particle size of 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, or 50 μm or less. The lower limit of the particle size of the iron and steel slag powder is not particularly limited and is appropriately determined depending on the desired handleability, etc., and is, for example, 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, or 40 μm or more, etc. In terms of the average particle size, the iron and steel slag powder may preferably be, for example, in the range of 20 μm or more to 200 μm or less, preferably in the range of 30 μm or more to 100 μm or less, preferably in the range of 30 μm or more to 70 μm or less, 40 μm or more to 60 μm or less, or 40 μm or more to 55 μm or less.

[0015] (Suspension of growth promoter) In one embodiment of the present invention, the growth promoter is used as an aqueous suspension in which it is suspended in water. This aqueous suspension exhibits, for example, alkalinity due to partial dissolution of the suspended components, and in a more specific example, may exhibit an alkalinity within the range of pH 9 or more, pH 9.5 or more, or pH 10 or more, and pH 12.5 or less, or pH 12 or less. That is, this aqueous suspension exhibits, for example, a weak to strong alkaline (pH 11 or more).

[0016] Furthermore, when the growth promoter is steel slag, from the viewpoint of promoting seed germination, the steel slag is preferably suspended in the suspension at a concentration of 1 mg / mL or more, or at a concentration of 2 mg / mL or more. More preferably, the steel slag is suspended at a concentration of 5 mg / mL or more, or at a concentration of 10 mg / mL or more. The upper limit of the steel slag concentration is not particularly limited, but is, for example, 500 mg / mL or less, 250 mg / mL or less, 200 mg / mL or less, or 150 mg / mL or less.

[0017] When the growth promoter is steel slag, from the viewpoint of promoting the growth of cotyledons, it may be preferable that the steel slag is suspended in the suspension at a concentration of 2 mg / mL or more, 5 mg / mL or more, or 10 mg / mL or more. The upper limit of the concentration of the steel slag is not particularly limited, but is, for example, 500 mg / mL or less, 250 mg / mL or less, 200 mg / mL or less, or 150 mg / mL or less.

[0018] (Seeds, treatments on seeds, and treated seeds) Regarding one embodiment of the present invention, the type of seed is not particularly limited, and examples thereof include seeds used for industrial purposes including agriculture and horticulture. Typical examples include ungerminated rice (particularly paddy rice) seeds, seeds of beans such as wheat, corn, and soybeans, seeds of other vegetables, and hard seeds, and other typical examples include seeds before sowing for seedlings (the type of plant is not limited to rice, etc.).

[0019] A preferred example of the seed treatment method using the above suspension includes a soaking step of soaking seeds in the above suspension. The temperature conditions for performing the soaking step are not particularly limited and may be appropriately set depending on the type of seed, etc. The temperature conditions may be the same as the outside air temperature, or may be temperature controlled in a facility, etc. An example of the temperature conditions for performing the soaking step is in the range of 5°C or more and 35°C or less, in the range of 10°C or more and 35°C or less, in the range of 15°C or more and 35°C or less, in the range of 15°C or more and 25°C or less, and in the range of 25°C or more and 35°C or less. The period for performing the soaking step of soaking seeds in the suspension is not particularly limited, and examples thereof include a range of 5 hours to 100 hours, a range of 10 hours to 100 hours, a range of 15 hours to 100 hours, and a range of 20 hours to 100 hours.

[0020] This soaking step can be carried out, for example, as one step in the seed preparation work. Seed preparation is a process of preparing seeds in a slightly germinated state called pigeon breast through the steps of seed selection, disinfection, soaking, and germination, particularly in rice (paddy rice) seeds. The soaking step in one embodiment of the present invention can be carried out as a soaking step in the seed preparation, which results in, for example, shortening the soaking period and / or omitting the germination step. In addition, by shortening the soaking period, water exchange during the soaking period can also be omitted. The soaking step in one embodiment of the present invention can be carried out as a germination step in the seed preparation, which results in growth promotion effects such as promoting the elongation of coleoptiles and promoting the development of the root system (for example, root elongation, crown root development, root hair development, etc.). Both the soaking step and the germination step in the seed preparation can be carried out as this soaking step.

[0021] The seeds treated with the above suspension can be used, for example, as seeds for raising seedlings or seeds for direct sowing. The treated seeds show a significant improvement in germination rate in any use, compared to untreated seeds. In addition, as shown in the examples described later, by appropriately changing the treatment conditions, it is possible to prepare seeds in a desired state according to the use, such as a pigeon breast state, a state in which the elongation of the coleoptile has been promoted to a desired level, a state in which the development of the root system has been promoted to a desired level, etc.

[0022] (Processes other than the immersion process) In one embodiment of the present invention, the method may further include a step of sowing the treated seeds for seedling raising or a step of directly sowing the seeds in soil (paddy field in the case of paddy rice). The method of direct sowing is not particularly limited, and may be, for example, surface sowing or subsoiling.

[0023] (Rice seed growth promoter) An example of the above growth promoter is a growth promoter for rice (particularly paddy rice) seeds containing steel slag. This growth promoter is used to prepare a composition for promoting the growth of rice seeds, as follows: 1) an aqueous suspension in which steel slag is suspended in water, 2) a supernatant of the aqueous suspension of steel slag, or 3) a supernatant and sediment of the aqueous suspension of steel slag (steel slag). Here, an example of the aqueous suspension does not contain a binder such as PVA (polyvinyl alcohol). Another example of the aqueous suspension substantially contains only water and steel slag. This rice seed growth promoter is, for example, for preparing rice seeds in a pigeon-breasted state, for preparing rice seeds in a state in which coleoptile elongation has been promoted, and for preparing rice seeds in a state in which root system development has been promoted.

[0024] (summary) For example, the following inventions are also included in the scope of the present invention. (1) A method for promoting seed growth, comprising a soaking step of soaking the seeds in a suspension containing a growth promoter including calcium oxide (CaO) and silica (SiO2). (2) The growth promotion method according to (1), wherein the growth promoter further contains magnesium oxide (MgO). (3) The growth promotion method according to (1) or (2), wherein the growth promoter contains calcium oxide at 30% by mass or more and 50% by mass or less and silica at 5% by mass or more and 15% by mass or less. (4) The growth promotion method according to any one of (1) to (3), wherein the growth promoter is a steel slag. (5) The growth promotion method according to (4), wherein the suspension contains the steel slag suspended at a concentration of 2 mg / mL or more. (6) A growth promotion method according to (4) or (5), wherein the steel slag is steel slag powder having a particle diameter of 200 μm or less. (7) A growth promotion method described in any one of (1) to (6), wherein the suspension is alkaline, having a pH of 10 or more and a pH of 12 or less. (8) The method for promoting growth described in any one of (1) to (7), wherein the seeds are ungerminated rice seeds. (9) A growth promotion method described in any of (1) to (8), wherein in the soaking step, the seeds are soaked in the suspension for 20 hours or more and 100 hours or less in an environment of 15°C or more and 35°C or less. (10) A rice seed growth promoter comprising an iron and steel slag. A rice seed growth promoter comprising an iron and steel slag suspension. The iron and steel slag suspension is, for example, any one of (1) to (7) above.

[0025] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. EXAMPLES

[0026] Example 1: Germination of seeds soaked in a slag suspension Slag A suspension (25 mg / mL) and slag B suspension (25 mg / mL) were prepared by adding 1 g of pulverized slag A or slag B per 40 mL of distilled water (25 mg / mL). Slag A was converter slag (product name: S-Minecal, manufactured by Sangyo Shinko Co., Ltd.), and slag B was pretreated slag (product name: Noriyaku Up, manufactured by Sangyo Shinko Co., Ltd.). The composition analysis results of the steel slags A and B are shown in Table 1. [Table 1]

[0027] The meaning of each component shown in Table 1 is as follows: T-CaO (total lime), CaO (exchangeable lime), T-MgO (total magnesium), MgO (exchangeable magnesium), T-P2O5 (total phosphoric acid), P2O5 (available phosphoric acid), T-Fe2O3 (total iron oxide), Fe2O3 (available iron oxide), T-SiO2 (total silicic acid), SiO2 (available silicic acid), T-Mn (total manganese), Mn (exchangeable manganese), TB (total boron), B (hot water soluble boron).

[0028] Of the components listed in Table 1 above, the amount of calcium in the slag A suspension was 159-212 mg / L, the amount of ionic silica was 3-4 mg / L, the amount of soluble manganese was 0.1 mg / L-0.2 mg / L, the amount of boron calculated as borate ion was 0.5 mg / L, the amount of phosphate ion was less than 1.0 mg / L (below the detection limit), the amounts of Fe(II) ions and Fe(III) ions were less than 0.1 mg / L (below the detection limit), and the amount of magnesium was less than 0.1 mg / L (below the detection limit). The calcium content in the slag B suspension was 305-333 mg / L, the ionic silica content was 7 mg / L, the soluble manganese content was 0.5 mg / L-0.6 mg / L, the boron content was 0.6 mg / L calculated as borate ion, the Fe(II) ion content was 1 mg / L-1.2 mg / L, the magnesium content was 0.1 mg / L, the phosphate ion content was less than 1.0 mg / L (below the detection limit), and the Fe(III) ion content was less than 1 mg / L (below the detection limit). Both the slag A suspension and the slag B suspension were alkaline, with their pH values ​​generally ranging from 10 to 12. Furthermore, no oxygen generation was confirmed in either the slag A suspension or the slag B suspension.

[0029] Each slag suspension or distilled water used as a control was poured into a tube, Kinuhikari seeds were added to each, and soaked for 4 days at 20°C. After soaking, the calcium content in slag A suspension was 71.4-85.8mg / L, the ionic silica content was 10-13mg / L, the soluble manganese content was 0.2mg / L-0.3mg / L, the boron content was 0.9mg / L-1.0mg / L in terms of borate ion, the Fe(II) ion content was 0.1mg / L-0.2mg / L, the magnesium content was 2.7mg / L, the phosphate ion content was less than 1.0mg / L (below the detection limit), and the Fe(III) ion content was less than 0.1mg / L (below the detection limit). The calcium content in the slag B suspension after soaking was 206-225 mg / L, the ionic silica content was 85-97 mg / L, the soluble manganese content was 0.8 mg / L-1.1 mg / L, the boron content was 1.0 mg / L-1.1 mg / L in terms of borate ion, the Fe(II) ion content was 1.1 mg / L-1.3 mg / L, the magnesium content was 2.2-3.9 mg / L, the phosphate ion content was less than 1.0 mg / L (below the detection limit), and the Fe(III) ion content was less than 1 mg / L (below the detection limit).

[0030] The image of the seeds after soaking is shown in Figure 1. Figure 1 is a diagram comparing the germination of seeds soaked in slag suspensions. As shown in Figure 1, the seeds soaked in distilled water did not germinate, but the seeds soaked in slag A suspension and the seeds soaked in slag B suspension both germinated to the pigeon breast size.

[0031] Example 2: Germination of seeds soaked in a slag suspension The seeds soaked in Example 1 were further placed in the suspension at 30° C. for 1 day to induce germination. The results are shown in Figure 2. Figure 2 is a diagram comparing the germination of seeds soaked in a slag suspension.

[0032] As shown in the third row of images from the top of Figure 2, only a few of the seeds germinated in distilled water germinated, but both the seeds germinated in the slag A suspension and the seeds germinated in the slag B suspension showed more promoted coleoptile elongation than the seeds germinated in distilled water.

[0033] In addition, when a similar test was conducted under shallow water conditions (soaking and germinating seeds in a petri dish), which is not performed in actual soaking and germination treatment, the elongation of coleoptiles was confirmed even in distilled water, as shown in the bottom row of images in Figure 2. From this result, it can be said that growth can be guaranteed by using a slag suspension, even when the dissolved oxygen concentration is lower than in shallow water conditions.

[0034] Example 3: Rooting of seeds immersed in a slag suspension The pigeon-thorax seeds obtained in Example 1 were taken out of the suspension and placed on a sieve in a thermo-hygrostat heated to 30° C. for two days to carry out a rooting treatment. The results are shown in Figure 3. Figure 3 is a diagram comparing the rooting of seeds immersed in slag suspensions.

[0035] As shown in images A to F in Figure 3, the elongation of coleoptiles and seminal roots was promoted in the seeds rooted with the slag A suspension and the seeds rooted with the slag B suspension, compared to the seeds rooted with distilled water. In addition, the development of crown and lateral roots was promoted in the seeds rooted with the slag A suspension and the seeds rooted with the slag B suspension, which was not observed in the seeds rooted with distilled water.

[0036] (Example 4: Germination of seeds soaked in slag suspension by different sowing methods) The pigeon-breasted seeds obtained in Example 1 were sown in pots by the following method, and the number of sprouts was counted. As the seedling raising method A, the seeds were sown in culture soil, covered with soil, and steam-type germination treatment was performed under conditions of 30°C for 2 days, and then managed at 25°C. As the surface sowing method B, the seeds were sown on the surface of puddled paddy field soil and managed at 25°C without covering with soil. As the shallow soil sowing method C, the seeds were sown on the surface of puddled paddy field soil, covered with soil 2mm, and managed at 25°C. As the subsoil sowing method D, the seeds were sown on the surface of puddled paddy field soil, covered with soil 10mm, and managed at 25°C. As the Italian-style direct sowing method E, the seeds were sown on the surface of flooded paddy field soil, not covered with soil, and maintained at a water depth of 4cm for 2 days after sowing, and then managed at 25°C.

[0037] The number of seeds that emerged from the pots sown by each method was counted 5, 10, and 15 days after sowing, and the percentage of each seed out of 100 seeds was calculated. The results are shown in Figures 4 and 5. Figures 4 and 5 are graphs comparing the number of seeds that emerged from the seeds immersed in the slag suspension by sowing method.

[0038] As shown in Figures 4 and 5, in all sowing methods, the germination rate of seeds soaked in the slag suspension was improved compared to seeds soaked in distilled water.

[0039] (Example 5: Relationship between slag particle size and number of germinated seeds) A slag suspension (25 mg / mL) was prepared by adding 1 g of slag A per 40 mL of distilled water. As slag A, four types of slag with different particle shapes were prepared: a commonly available granular slag (S-Minecal (product name) manufactured by Sangyo Shinko Co., Ltd.; hereinafter, also referred to as "coarse-fine mixed slag"), coarse-grained slag and fine-grained slag obtained by sieving the coarse-fine mixed slag, and fine-grained slag obtained by pulverizing the coarse-fine mixed slag, and a suspension was prepared for each of them. Images of each slag and their average particle diameters are shown in FIG. 6. FIG. 6 is a diagram showing the particle diameters of the slags used in the examples.

[0040] The average particle size of the coarse-fine mixed slag, the coarse slag, and the fine slag was measured by a sieving method. A low-tap sieving device, DuraTap (Advantech), was used for the measurement. The measurement conditions were a sieving time of 10 minutes and a particle size range of 9500 to 53 μm.

[0041] The average particle size of the fine slag powder was measured by the laser diffraction / scattering method. A laser diffraction / scattering particle size distribution analyzer LMS-2000e (manufactured by Seishin Enterprise Co., Ltd.) was used for the measurement. The measurement method consisted of performing a blank measurement using only the dispersion medium, then putting an appropriate amount of sample into a dispersion tank, dispersing the sample with ultrasonic waves, and measuring the particle size distribution using a circulation method. The measurement conditions were a measurement range of 0.020 to 2000.00 μm, ion-exchanged water as the dispersion medium, and one minute of ultrasonic dispersion time.

[0042] Kinuhikari seeds were soaked in each slag suspension at 20°C for four days, and then germination was stimulated at 30°C for one day. The number of germinated seeds and average coleoptile length of seeds stimulated to germinate in each of the four slag suspensions with different grain sizes were calculated, and the results are shown in Figure 7. Figure 7 is a graph showing the results of investigating the relationship between slug particle size and the number of germinated seeds and the average coleoptile length.

[0043] As shown in Figure 7, the number of germinated seeds was the highest when the fine slag suspension was used, and the average coleoptile length was also the longest. This result indicates that the growth-promoting effect of slag can be improved by preparing it into a fine powder finer than the fine particles with an average particle size of 201 μm.

[0044] (Example 6: Relationship between slag suspension concentration and number of germinated seeds) Slag A was added to 40 mL of distilled water to prepare a slag suspension. The slag suspension was prepared to four concentrations: 2.5 mg / mL (0.1 g / 40 mL), 12.5 mg / mL (0.5 g / 40 mL), 25 mg / mL (1 g / 40 mL), and 125 mg / mL (5 g / 40 mL). Images of the suspensions of each concentration are shown in FIG. 8. FIG. 8 shows the slag suspensions used in the examples by concentration.

[0045] Kinuhikari seeds were soaked in each slag suspension at 20°C for four days, and then germination was stimulated at 30°C for one day. The number of germinated seeds and average coleoptile length of seeds stimulated to germinate in each of the four concentrations of slag suspension were calculated, and the results are shown in Figure 9. Figure 9 is a graph showing the results of investigating the relationship between slag suspension concentration and the number of germinated seeds.

[0046] As shown in Figure 9, the number of germinated seeds increased and coleoptile elongation was promoted in a slag concentration-dependent manner. The number of germinated seeds reached a plateau at slag concentrations of 12.5 mg / mL or higher. This result indicates that the seed growth promotion effect can be controlled by adjusting the slag concentration. [Industrial Applicability]

[0047] The present invention can be used in the fields of agriculture, breeding, etc.

Claims

1. A method for promoting seed growth, comprising: Calcium oxide (CaO) and silica (SiO ２ The method includes a soaking step of soaking the seeds in a suspension containing a growth promoter comprising: The growth promoter is steel slag, The growth promotion method, wherein the soaking step is a step of seed preparation.

2. The growth promotion method according to claim 1 , wherein the growth promoter further comprises magnesium oxide (MgO).

3. 3. The growth promotion method according to claim 1 or 2, wherein the growth promoter contains calcium oxide in an amount of 30% by mass or more and 50% by mass or less, and silica in an amount of 5% by mass or more and 15% by mass or less.

4. The growth promotion method according to claim 1 , wherein the suspension contains the steel slag suspended at a concentration of 2 mg / mL or more.

5. The growth promotion method according to claim 1 , wherein the steel slag is steel slag powder having a particle diameter of 200 μm or less.

6. The growth promotion method according to claim 1 or 2, wherein the suspension is alkaline, having a pH of 10 or more and a pH of 12 or less.

7. The method for promoting growth according to claim 1 or 2, wherein the seeds are ungerminated rice seeds.

8. The growth promotion method according to claim 1 or 2, wherein in the soaking step, the seeds are soaked in the suspension for 20 hours or more and 100 hours or less in an environment of 15°C or more and 35°C or less.

9. The water suspension contains steel slag suspended in water. For preparing rice seeds in a pigeon-thorax state, for preparing rice seeds in a state where coleoptile elongation has been promoted, or for preparing rice seeds in a state where root system development has been promoted, A growth promoter for rice seeds.

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