Plant growth stimulant

Abstract

To provide a plant growth promoter containing a lignin compound, which can efficiently promote plant growth, as an active ingredient.SOLUTION: A plant growth promoter contains a lignosulfonic acid component having a phenolic hydroxyl group content of 0.1-3.5 wt.%, a methoxyl group content of 1.0-15.0 wt.%, and a sulfone-group-derived sulfur atom content of 2.0% or more. A plant production method includes cultivating plants using the plant growth promoter. A plant cultivation kit comprises the plant growth promoter and plant seeds or seedlings.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a plant growth promoter. [Background technology]

[0002] Lignin is a high-molecular-weight phenolic polymer found in plant tissues. When plants are decomposed by soil microorganisms, lignin degradation products are produced as intermediate products. These lignin degradation products combine with peptides and amino acids produced by the decomposition of microbial proteins to generate humic acid. Humic acid promotes plant growth and also improves soil nutrient retention and activates soil microorganisms. For this reason, lignin has been used to promote the growth of crops and other plants.

[0003] Patent Document 1 describes a plant vitality agent containing a lignin decomposition product as an active ingredient, in which the aldehyde yield by alkali nitrobenzene oxidation is 10% by mass or more.

[0004] Patent Document 2 describes a plant growth promoter containing granular material of plant seed husk components, which contains 40% to 60% by mass of lignin. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-190331 [Patent Document 2] International Publication No. 2019 / 078209 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in order to further utilize lignin, there has been a need to develop lignin derivatives that can exhibit a higher growth-promoting effect on plants than the agents described in Patent Documents 1 and 2. However, there have been cases where yields could not be sufficiently improved. The present invention has been made in view of the above, and aims to provide a plant growth promoter containing a lignin-based compound as an active ingredient that can efficiently promote plant growth. [Means for solving the problem]

[0007] The present invention provides the following [1] to [7]. [1] A plant growth promoter containing a lignin sulfonic acid component having a phenolic hydroxyl group content of 0.1 to 3.5% by weight, a methoxyl group content of 1.0 to 15.0% by weight, and a sulfur atom content of 2.0% or more derived from sulfone groups. [2] Lignin sulfonic acid component, The reducing sugar content must be 35% by weight or less. The sulfur atom content is 3.0% by weight or more, and The sodium atom content must be 0.3% by weight or more. The agent described in [1], which satisfies at least one of the following conditions. [3] The agent according to [1] or [2], wherein the carboxyl group content of the lignin sulfonic acid component is 0.1 to 4.5 mmol / g. [4] The agent according to any one of items [1] to [3], wherein the weight-average molecular weight (RI) of the lignin sulfonic acid component is 3,000 or more. [5] The agent according to any one of [1] to [4], wherein the lignin sulfonic acid has substituents derived from (poly)alkylene oxide. A method for producing plants, comprising cultivating plants using any one of the agents described in items [6], [1], to [5]. A plant cultivation kit comprising any one of items [7](1) to [5) and plant seeds or seedlings. [Effects of the Invention]

[0008] According to the present invention, there is provided a plant growth promoter that can promote the growth of various plants. Since the plant growth promoter of the present invention can be applied regardless of the growth stage of the plant and the cultivation conditions, it can lead to an increase in the yield and income of crops in the agricultural field.

Mode for Carrying Out the Invention

[0009] [1. Lignin sulfonic acid component] The plant growth promoter of the present invention contains a lignin sulfonic acid component.

[0010] [Lignin sulfonic acid] The lignin sulfonic acid component is a component mainly containing lignin sulfonic acid and is usually derived from the sulfite cooking of pulp. Lignin sulfonic acid is a compound having a skeleton in which the carbon at the α-position of the side chain of the hydroxyphenylpropane structure of lignin is cleaved and a sulfone group is introduced.

[0011] Lignin sulfonic acid can take the form of a salt. Examples of the salt include monovalent metal salts, divalent metal salts, ammonium salts, and organic ammonium salts. Among these, calcium salts, magnesium salts, sodium salts, and calcium-sodium mixed salts are preferred.

[0012] [Substituent] Lignin sulfonic acid contains substituents other than the sulfone group. The substituents may be substituents derived from lignin or substituents that are introduced by a modification treatment and are not possessed by the original lignin. Examples of the substituents include hydroxyl groups (phenolic hydroxyl groups, alcoholic hydroxyl groups), methoxyl groups, carboxyl groups, sulfomethyl groups, aminomethyl groups, and (poly)alkylene oxide groups. Among these, it is more preferable to contain phenolic hydroxyl groups, methoxyl groups, sulfone groups, and (poly)alkylene oxide groups within a predetermined range. Thereby, the growth of plants can be promoted.

[0013] -Phenolic hydroxyl group- Phenolic hydroxyl groups are generally hydroxyl groups directly bonded to aromatic rings such as benzene. The phenolic hydroxyl group content is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, even more preferably 1.0% by weight or more, and even more preferably 1.1% by weight or more, based on the total amount of ligninsulfonic acid components. The upper limit is preferably 3.5% by weight or less, more preferably 3.3% by weight or less, even more preferably 3.0% by weight or less, and even more preferably 2.7% by weight or less. Therefore, the phenolic hydroxyl group content of ligninsulfonic acid is preferably 0.1 to 3.5% by weight, more preferably 0.5 to 3.3% by weight, even more preferably 1.0 to 3.0% by weight, and even more preferably 1.1 to 2.7% by weight. The phenolic hydroxyl group content can be quantified from the absorbance measurement using a spectrophotometer.

[0014] -Methoxyl group- A methoxyl group is a group represented by the formula -OCH3. The methoxyl group content is preferably 1.0% by weight or more, more preferably 3.0% by weight or more, even more preferably 5.0% by weight or more, and even more preferably 6.0% by weight or more, based on the total amount of lignin sulfonic acid components. The upper limit is preferably 15.0% by weight or less, more preferably 13.0% by weight or less, even more preferably 12.0% by weight or less, and even more preferably 11.5% by weight or less. Therefore, the methoxyl group content is preferably 1.0 to 15.0% by weight, more preferably 3.0 to 13.0% by weight, even more preferably 5.0 to 12.0% by weight, and even more preferably 6.0 to 11.5% by weight. The methoxyl group content of lignin can be measured by the Viebock and Schwappach methods.

[0015] -Sulfone group- A sulfone group (sulfonic acid group, sulfo group) is generally represented by the formula: -SO3 - M +The group is represented as (where M is a countercation (e.g., H, Na, Ca, Mg, NH4)). The sulfone group content can be indicated by the sulfur atom content derived from the sulfone group (sulfone group S content). The sulfone group S content is preferably 2.0% or more, more preferably 3.0% or more, even more preferably 4.0% or more, and even more preferably 4.5% or more, relative to the total amount of ligninsulfonic acid components. There is no particular upper limit, but it is preferably 10.0% or less, more preferably 9.0% or less, even more preferably 8.0% or less, and even more preferably 7.0% or less. Therefore, the sulfone group S content is preferably 2.0 to 10.0%, more preferably 3.0 to 9.0%, even more preferably 4.0 to 8.0%, and even more preferably 4.5 to 7.0%. The sulfone group S content can be determined by subtracting the inorganic sulfur atom content from the total sulfur atom content in ligninsulfonic acid.

[0016] -Carboxyl group- The carboxyl group is generally represented by the formula: -COOM + The group is represented as (where M is a countercation (e.g., H, Na, Ca, Mg, NH4)). The carboxyl group content is preferably within a predetermined range. That is, it is preferably 0.1 mmol / g or more per weight of the ligninsulfonic acid component, more preferably 0.3 mmol / g or more, and even more preferably 0.5 mmol / g or more. The upper limit is preferably 4.5 mmol / g or less, more preferably 4.0 mmol / g or less, and even more preferably 3.0 mmol / g or less. Therefore, the carboxyl group content is preferably 0.1 to 4.5 mmol / g, more preferably 0.3 to 4.0 mmol / g, and even more preferably 0.5 to 3.0 mmol / g. The carboxyl group content can be determined by neutralization titration.

[0017] -(Poly)alkylene glycol group- The (poly)alkylene glycol group is a substituent derived from (poly)alkylene oxide. The average number of added moles of alkylene oxide units constituting the polyalkylene glycol is usually 1 or more, 5 or more, or 10 or more, preferably 15 or more, more preferably 20 or more, even more preferably 25 or more, or 30 or more, and even more preferably 35 or more. This can result in good dispersibility. Among these, values ​​of 50 or more, 60 or more, 70 or more, 80 or more, or 90 or more are preferred because they further improve surface spreadability. The upper limit is usually 300 or less or 200 or less, preferably 190 or less, more preferably 180 or less, and even more preferably 170 or less. This can suppress a decrease in dispersion retention. Therefore, the average number of added moles is usually 10 to 200, preferably 15 to 190, more preferably 20 to 180, and even more preferably 25 to 170. On the other hand, it is preferably 25 to 300, more preferably 30 to 200, and even more preferably 35 to 150. The number of carbon atoms in polyalkylene glycol is not particularly limited, but is usually 2 to 18, preferably 2 to 4, and more preferably 2 to 3. Examples of alkylene oxide units include ethylene oxide units, propylene oxide units, and butylene oxide units, with ethylene oxide units or propylene oxide units being preferred. Examples of lignin sulfonic acids containing a (poly)alkylene oxide group include lignin derivatives described in International Publication No. 2021 / 066166.

[0018] [Inorganic components] The ligninsulfonic acid component may further contain inorganic components. Examples of inorganic components include inorganic salts of sulfur, calcium, sodium, magnesium, nitrogen, phosphorus, potassium, iron, ammonia, oxides of these inorganic salts (e.g., sulfur oxide, magnesium oxide, calcium oxide), hydroxides (e.g., magnesium hydroxide, calcium hydroxide, sodium hydroxide, ammonium hydroxide), carbon oxides (e.g., calcium carbonate, sodium carbonate), and nitric acid. The form of the inorganic component is not particularly limited and may be a countercation of ligninsulfonic acid or a free inorganic component (e.g., an inorganic component added during the production of ligninsulfonic acid). Of these, it is preferable to include at least one of sulfur, calcium, sodium, magnesium, nitrogen, phosphorus, and potassium.

[0019] -Sulfur ions- The sulfur ion content can be expressed as the sulfur atom content (total S content) contained in ligninsulfonic acid. The total S content is preferably 3.0% by weight or more, more preferably 4.0% by weight or more, and even more preferably 5.0% by weight or more. There is no particular upper limit, but it is preferably 10.0% by weight or less, more preferably 9.0% by weight or less, and even more preferably 8.0% by weight or less. Therefore, the S content is preferably 3.0 to 10.0% by weight, more preferably 4.0 to 9.0% by weight, and even more preferably 5.0 to 8.0% by weight. The total S content can be quantified by ICP emission spectrometry.

[0020] -Sulfur Oxide- Ligninsulfonic acid may contain sulfur oxides. Examples of sulfur oxides include sulfur dioxide (SO2), sulfur trioxide (SO3), and sulfur tetroxide (SO4), with SO3 and SO4 being preferred. The SO3 content is usually 0% or more, preferably 0.001% by weight or more, more preferably 0.005% by weight or more, and even more preferably 0.01% by weight or more or 0.04% by weight or more, as SO3 may change to SO4. The upper limit is preferably 3.0% by weight or less, more preferably 2.0% by weight or less, even more preferably 1.0% by weight or less, and even more preferably 0.5% by weight or less. Therefore, the SO3 content is usually 0 to 3.0% by weight, preferably 0.001 to 3.0% by weight, more preferably 0.005 to 2.0% by weight, even more preferably 0.01 to 1.0% by weight, and even more preferably 0.04 to 0.5% by weight. The SO4 content is preferably 0.2% by weight or more, more preferably 0.4% by weight or more, and even more preferably 0.5% by weight or more, 2.0% by weight or more, or 3.0% by weight or more. The upper limit is preferably 10% by weight or less, more preferably 9.5% by weight or less, and even more preferably 9.0% by weight or less. Therefore, the SO4 content is preferably 0.2 to 10% by weight, more preferably 0.4 to 9.5% by weight, even more preferably 0.5 to 9.0% by weight, and even more preferably 2.0 to 9.0% by weight or 3.0 to 9.0% by weight. The sulfur oxide content can be quantified by ion chromatography.

[0021] -Percentage of sulfonate group S in the total S content- The proportion of sulfur atoms derived from sulfone groups to the total sulfur atom content in ligninsulfonic acid is preferably 0.5 or higher, and more preferably 0.6 or higher. The upper limit is usually 0.95 or lower, preferably 0.9 or lower, but there are no particular restrictions.

[0022] -The proportion of SO3 to SO4- The ratio of SO3 content to SO4 content in ligninsulfonic acid is usually 0 or greater, preferably 0.01 or greater, and more preferably 0.02 or greater. The upper limit is preferably 0.5 or less, and more preferably 0.4 or less.

[0023] -Sodium ions, calcium ions, magnesium ions- Na + Ca 2+ Mg 2+ The content of each ion can be expressed as the content of each atom. The sodium atom content (Na content) is preferably 0.3% by weight or more, more preferably 0.4% by weight or more, and even more preferably 0.5% by weight or more. There is no particular upper limit, but it is preferably 10.0% by weight or less, more preferably 9.0% by weight or less, and even more preferably 8.0% by weight or less. Therefore, the Na content is preferably 0.3 to 10.0% by weight, more preferably 0.4 to 9.0% by weight, and even more preferably 0.5 to 8.0% by weight. The calcium atom content (Ca content) is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, and even more preferably 0.03% by weight or more. The upper limit is preferably 5.0% by weight or less, more preferably 4.0% by weight or less, and even more preferably 1.0% by weight or less. Therefore, the Ca content is preferably 0.001 to 5.0% by weight, more preferably 0.01 to 4.0% by weight, and even more preferably 0.03 to 1.0% by weight. The magnesium atom content (Mg content) is preferably 0.05% by weight or more, more preferably 0.07% by weight or more, and even more preferably 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 2.0% by weight or more, 3.0% by weight or more, or 3.2% by weight or more. The upper limit is preferably 10.0% by weight or less, more preferably 8.0% by weight or less, and even more preferably 5.0% by weight or less. Therefore, the Mg content is preferably 0.05 to 10.0% by weight, more preferably 0.07 to 8.0% by weight, and even more preferably 0.1 to 5.0% by weight, 0.5 to 5.0% by weight, 1.0 to 5.0% by weight, 2.0 to 5.0% by weight, 3.0 to 5.0% by weight, or 3.2 to 5.0% by weight. The Na, Ca, and Mg content can be quantified by inductively coupled plasma (ICP) spectroscopy.

[0024] -Reducing sugars- The lignin sulfonic acid component preferably further contains reducing sugars. In this specification, reducing sugars refer to sugars that have reducing properties, that is, sugars that have the property of producing an aldehyde group or a ketone group in a basic solution. Examples of reducing sugars include all monosaccharides; disaccharides such as maltose, lactose, arabinose, and sucrose invert sugar; and polysaccharides. Reducing sugars usually include cellulose, hemicellulose, and their decomposition products. Examples of cellulose and hemicellulose decomposition products include monosaccharides such as rhamnose, galactose, arabinose, xylose, glucose, mannose, and fructose; oligosaccharides such as xylooligosaccharides and cellooligosaccharides; and modified products thereof. Modified products are chemically modified products such as oxidation and sulfonation, and examples include sugar derivatives in which functional groups such as hydroxyl groups, aldehyde groups, carbonyl groups, and sulfo groups are introduced into the sugar skeleton, and compounds in which two or more such sugar derivatives are bonded together.

[0025] The reducing sugar content is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, 0.5% by weight or more, or even more preferably 2.0% by weight or more. The upper limit is preferably 35% by weight or less, more preferably 30% by weight or less, and even more preferably 25% by weight or less. Therefore, the reducing sugar content is preferably 0.1 to 35% by weight, more preferably 0.3 to 30% by weight, 0.5 to 25% by weight, or even more preferably 2.0 to 25% by weight. The reducing sugar content can be calculated as a glucose equivalent value by the Somogyi-Schaffer method.

[0026] [Other ingredients] The lignin sulfonic acid component may contain components other than those listed above. Examples include organic components and ash. Examples of organic components include low molecular weight organic substances such as formic acid, acetic acid, propionic acid, valerian acid, pyruvic acid, succinic acid, and lactic acid (for example, organic acids with 5 or fewer carbon atoms).

[0027] [Weight average molecular weight (RI)] The weight-average molecular weight (RI) of the lignin sulfonic acid component is preferably 3,000 or more, more preferably 3,500 or more, even more preferably 3,700 or more, and even more preferably 4,000 or more. There is no particular upper limit, but it is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. Therefore, the weight-average molecular weight (RI) is preferably 3,000 to 50,000, more preferably 3,500 to 50,000, even more preferably 3,700 to 40,000, and even more preferably 4,000 to 35,000. In this specification, the weight-average molecular weight (RI) is the weight-average molecular weight determined by GPC using a differential refractive index detector (RI).

[0028] [Weight average molecular weight (UV)] The weight-average molecular weight (UV) of the lignin sulfonic acid component is preferably 9,000 or more, more preferably 11,000 or more, even more preferably 15,000 or more, and even more preferably 17,000 or more. There is no particular upper limit, but it is more preferably 70,000 or less, even more preferably 60,000 or less, and even more preferably 57,000 or less. Therefore, the weight-average molecular weight (UV) is preferably 9,000 to 70,000, more preferably 11,000 to 70,000, even more preferably 15,000 to 60,000, and even more preferably 17,000 to 57,000. In this specification, the weight-average molecular weight (UV) is the weight-average molecular weight determined by GPC using an ultraviolet-visible absorbance detector.

[0029] -Ratio of weight-average molecular weight RI / UV- The ratio of weight-average molecular weight (RI) to weight-average molecular weight (UV) is preferably 0.95 or less, and more preferably 0.93 or less. The lower limit is usually 0.4 or more, preferably 0.5 or more, and there are no particular restrictions.

[0030] As the lignin sulfonic acid component, for example, you may select and use Sanlighon (scheduled to be sold by Nippon Paper Industries Co., Ltd. from July 2022 onwards) that has the above substituents and inorganic component amounts.

[0031] [1.2 Method for producing lignin sulfonic acid] The method for producing ligninsulfonic acid is not particularly limited, but for example, it can be produced by a method involving sulfite treatment from lignocellulose raw materials, or by a method of decomposing lignin and sulfonating it. By adjusting the production conditions, the types and content of substituents in the ligninsulfonic acid component, as well as the types and content of each component such as inorganic components and reducing sugars, can be adjusted.

[0032] -Raw materials- Lignocellulose raw materials, as an example of raw materials, are not particularly limited as long as they contain lignocellulose in their composition. Examples include pulp raw materials such as wood and non-wood. Examples of wood include coniferous wood such as radiata pine, Yezo spruce, Japanese red pine, cedar, and cypress, and broadleaf wood such as birch and beech. The age of the tree and the part from which the wood is harvested are not considered. Therefore, wood harvested from trees of different ages or from different parts of the tree may be used in combination. Examples of non-wood include bamboo, kenaf, reeds, and rice. Lignocellulose raw materials may be used alone or in combination of two or more types.

[0033] Other examples of lignin as a raw material include, for example, naturally derived lignin and artificially manufactured lignin (e.g., dehydrogenated polymers of hydroxycinnamol alcohol analogs).

[0034] -Sulfurous acid treatment- Sulfite treatment can be carried out by contacting the lignocellulose raw material with at least one of sulfite and sulfite salts. The conditions for sulfite treatment are not particularly limited, and any conditions that allow a sulfo group to be introduced to the α-carbon atoms of the side chains of lignin contained in the lignocellulose raw material are acceptable.

[0035] The sulfite treatment is preferably carried out by the sulfite pulping method. This allows for more quantitative sulfonation of the lignin in the lignocellulose raw material. The sulfite pulping method is a method of reacting the lignocellulose raw material at high temperature in a solution of at least one of sulfite and sulfite salts (e.g., aqueous solution: pulp). This method is advantageous in terms of economy and ease of implementation because it is industrially established and implemented as a method for producing sulfite pulp.

[0036] Examples of sulfite salts used in sulfite pulping include magnesium salts, calcium salts, sodium salts, and ammonium salts.

[0037] The sulfurous acid (SO2) concentration in at least one of the sulfurous acid and sulfite solutions is not particularly limited, but the ratio of the mass (g) of SO2 to 100 mL of the reaction solution is preferably 1 g / 100 mL or more, and more preferably 2 g / 100 mL or more when sulfurous acid pulping is performed. The upper limit is preferably 20 g / 100 mL or less, and more preferably 15 g / 100 mL or less when sulfurous acid pulping is performed. The SO2 concentration is preferably between 1 g / 100 mL and 20 g / 100 mL, and more preferably between 2 g / 100 mL and 15 g / 100 mL when sulfurous acid pulping is performed.

[0038] The pH value for sulfur dioxide treatment is not particularly limited, but is usually 10 or less. When sulfur dioxide pulping is performed, it is preferable to do so under acidic conditions, more preferably at a pH of 5 or less, and even more preferably at a pH of 3 or less. This allows for efficient extraction of lignin derivatives (e.g., ligninsulfonic acid), resulting in higher quality pulp. The lower limit of the pH value is preferably 0.1 or higher, and more preferably 0.5 or higher when sulfur dioxide pulping is performed. The pH value during sulfur dioxide treatment is preferably 0.1 to 10, more preferably 0.5 to 5 when sulfur dioxide pulping is performed, and even more preferably 0.5 to 3.

[0039] The temperature for sulfur dioxide treatment is not particularly limited, but is preferably 170°C or lower, and more preferably 150°C or lower when sulfur dioxide pulping is performed. The lower limit is preferably 70°C or higher, and more preferably 100°C or higher when sulfur dioxide pulping is performed. The temperature conditions for sulfur dioxide treatment are preferably 70 to 170°C, and more preferably 100 to 150°C when sulfur dioxide pulping is performed. The treatment time for sulfur dioxide treatment is not particularly limited and depends on the conditions of the sulfur dioxide treatment, but 0.5 to 24 hours is preferred, and 1.0 to 12 hours is more preferred.

[0040] In sulfurous acid treatment, it is preferable to add a compound that supplies countercations to ligninsulfonic acid. By adding a compound that supplies countercations, the pH value during sulfurous acid treatment can be kept constant. Examples of compounds that supply countercations include MgO, Mg(OH)2, CaO, Ca(OH)2, CaCO3, NH3, NH4OH, NaOH, NaHCO3, and Na2CO3. Magnesium ions and sodium ions are preferred as countercations.

[0041] In sulfurous acid treatment, when using a solution of at least one of sulfurous acid and sulfites, the solution may, if necessary, contain, in addition to SO2, the above-mentioned countercation (salt) and pulping agents (e.g., cyclic ketone compounds such as anthraquinone sulfonates, anthraquinones, and tetrahydroanthraquinones).

[0042] There are no limitations on the equipment used in the sulfur dioxide treatment process; for example, generally known equipment for manufacturing dissolved pulp can be used.

[0043] Intermediate products can be separated from solutions of at least one of sulfurous acid and sulfites by conventional methods. Examples of separation methods include separating the sulfurous acid effluent after sulfurous acid pulping (e.g., by filtration).

[0044] Ligninsulfonic acid obtained by sulfite treatment (for example, as filtrate or filtration residue after filtering insoluble matter from the sulfite solution, preferably as filtrate) may be used as is, or concentrated as necessary, as the active ingredient ligninsulfonic acid component. On the other hand, other treatments may be performed as necessary. This can increase the purity or introduce other substituents that are not originally present in the raw material. Examples of other treatments include alkali treatment, oxidation treatment, dialysis treatment, ultrafiltration treatment, modification treatment, and combinations thereof.

[0045] (Alkaline treatment) Alkaline treatment involves placing the sample under alkaline conditions. Alkaline conditions typically mean placing the sample in an aqueous solution with a pH of 8 or higher, preferably 9 or higher. The upper limit of the pH value is usually 14.

[0046] In alkaline treatment, an alkaline substance is typically brought into contact with the sulfur dioxide treatment material. The alkaline substance is not particularly limited, but examples include calcium hydroxide, magnesium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia. Among these, sodium hydroxide and calcium hydroxide are preferred. The alkaline substance may be used alone or in combination of two or more.

[0047] Examples of methods for contacting a sulfurous acid-treated material with an alkaline substance include preparing a dispersion or solution of the sulfurous acid-treated material (e.g., an aqueous dispersion, an aqueous solution) and adding the alkaline substance to the dispersion or solution, or adding a solution or dispersion of the alkaline substance (e.g., an aqueous dispersion, an aqueous solution) to the sulfurous acid-treated material.

[0048] The temperature of the alkali treatment is not particularly limited, but is preferably 40°C or higher, and more preferably 60°C or higher. The upper limit is preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower.

[0049] The amount of alkaline substance in the alkaline treatment is preferably 0.5 to 40% by mass, and more preferably 1.0 to 30% by mass, relative to the mass of the aqueous solution or dispersion when preparing an aqueous solution or dispersion by dispersing the alkaline treatment extract in an aqueous solvent (e.g., water).

[0050] The duration of the alkaline treatment is not particularly limited, but is preferably 0.1 hours or longer, and more preferably 0.5 hours or longer. The upper limit is preferably 10 hours or less, and more preferably 6 hours or less.

[0051] Prior to alkaline treatment, if necessary, the sulfurous acid treatment material may be dissolved, dispersed, or its concentration adjusted (preparation of a solution or dispersion in an aqueous solvent such as water). Dispersion can be performed by passing through a disc refiner, using a mixer, adding to a disperser, or kneading. Concentration adjustment can be performed, for example, using an aqueous solvent such as water.

[0052] (Oxidation treatment) The oxidation treatment can be performed on the treated material obtained after sulfurous acid treatment (e.g., the filtrate after filtration) or on the treated material after alkali treatment. The oxidation treatment can be carried out using an appropriate oxidizing agent. If the oxidizing agent is a gas, it can be carried out by passing the gas through the filtrate. If the oxidizing agent is a liquid, it can be carried out by adding the liquid to the filtration residue or filtrate. The oxidizing agent is preferably air, oxygen, hydrogen peroxide, ozone, or a combination thereof. The oxidation treatment is preferably carried out under alkaline conditions (alkali oxidation treatment). The treatment pH for alkali oxidation treatment is usually 8 or higher, preferably 10 or higher, and more preferably 12 or higher. The temperature for oxidation treatment is usually 20 to 200°C, preferably 50 to 180°C. The duration of oxidation treatment is usually preferably 0.1 hours or more, more preferably 0.5 hours or more. The upper limit is preferably 5 hours or less, and more preferably 3 hours or less.

[0053] (Dialysis treatment or UF treatment) Dialysis can be performed on the treated material obtained after sulfurous acid treatment (e.g., the filtrate after filtration). Examples of dialysis membranes include cellulose-based membranes such as cellulose acetate, and synthetic polymer membranes such as ethylene vinyl alcohol, polyacrylonitrile, polymethyl methacrylate, polysulfone, and polyethersulfone. The molecular weight fraction is usually 5,000 to 100,000, preferably 7,000 to 80,000, and more preferably 10,000 to 50,000.

[0054] Ultrafiltration (UF treatment) can be used instead of dialysis. Known UF membranes can be used, such as hollow fiber membranes, spiral membranes, tubular membranes, and flat membranes. The material of the UF membrane can be any known material, such as cellulose acetate, aromatic polyamide, polyvinyl alcohol, polysulfone, polyvinylidene fluoride, polyethylene, polyacrylonitrile, or ceramic. Commercially available UF membranes may also be used.

[0055] The molecular weight cutoff of the UF membrane is preferably 5,000 to 30,000, more preferably 10,000 to 25,000, and even more preferably 15,000 to 23,000. Using a UF membrane with a molecular weight cutoff of 5,000 or more can prevent the separation rate of the processing solution from becoming excessively slow. Using a UF membrane with a molecular weight cutoff of 30,000 or less can prevent lignin from not being separated from the processing solution.

[0056] The concentration ratio achieved by UF treatment using a UF membrane can be set arbitrarily. In other words, the UF treatment should be stopped when the amount of concentrated liquid flowing out reaches the desired amount. Preferably, the concentration is 2 to 6 times. Concentrating by 2 to 6 times means that the amount of the original solution (black liquor) is reduced to 1 / 2 to 1 / 6 of its original volume.

[0057] The temperature of the treatment solution during UF treatment is not particularly limited. For example, 20 to 80°C is preferred, and 20 to 70°C is more preferred considering the heat resistance of the UF film material. The pH value of the treatment solution during UF treatment is preferably 2 to 11. The solid content concentration (w / w) of the black liquor during UF treatment is preferably 2 to 30%, and more preferably 5 to 20%.

[0058] Examples of modification treatments include chemical modification methods such as hydrolysis, alkylation, alkoxylation, sulfonation, sulfonic acid esterification, sulfomethylation, aminomethylation, desulfonation, alkalization, and condensation reaction with (poly)alkylene oxide; and molecular weight fractionation of ligninsulfonic acid by ultrafiltration. Of these, one or more reactions selected from hydrolysis, alkoxylation, desulfonation, alkylation, and condensation reaction with (poly)alkylene oxide (for example, International Publication No. 2021 / 066166) are preferred as methods of chemical modification.

[0059] [1.3 Plant Growth Promoting Effect] Lignin sulfonic acid has the effect of promoting plant growth.

[0060] [plant] The target plants include herbaceous plants and woody plants. Examples of herbaceous plants include those from the Brassicaceae, Fabaceae, Cucurbitaceae, Solanaceae, Capsicumaceae, Rosaceae, Malvaceae, Poaceae, Alliaceae, Amaryllidaceae, Asteraceae, Amaranthaceae, Apiaceae, Zingiberaceae, Lamiaceae, Araceae, Convolvulaceae, Dioscoreaceae, and Nelumbonaceae families. Specifically, examples include leafy vegetables such as komatsuna, Chinese cabbage, onions, leeks, garlic, shallots, chives, pickled greens, bok choy, cabbage, cauliflower, broccoli, Brussels sprouts, asparagus, lettuce, salad greens, celery, spinach, garland chrysanthemum, parsley, mitsuba, celery, udo, myoga, butterbur, and shiso; fruit vegetables such as soybeans, edamame, broad beans, peas, cucumbers, eggplants, melons, corn, pumpkins, watermelons, tomatoes, bell peppers, strawberries, okra, and green beans; root vegetables such as carrots, turnips, radishes, burdock, potatoes, taro, sweet potatoes, yams, ginger, and lotus root; rice varieties (e.g., paddy rice, upland rice), wheat varieties (e.g., wheat, barley); and flowers. Examples of woody plants include the genera Cryptomeria (e.g., Japanese cedar), Chamaecyparis (e.g., Japanese cypress), Pinaceae (Pinus (e.g., Japanese black pine), Larch (e.g., Japanese larch, Daphne), Abies (e.g., Sakhalin fir)), Eucalyptus (e.g., Eucalyptus), Prunus (e.g., cherry, plum, Nanking cherry), Mango (e.g., mango), Acacia, Myrica, Quercus (e.g., Quercus acutissima), Vitis, Malus, Rosa, Camellia (e.g., tea), Jacaranda (e.g., Jacaranda), Pyrus (e.g., avocado), Pyrus (e.g., pear), and Sandalwood (e.g., sandalwood). Of these, herbaceous plants are preferred, and Brassicaceae and Fabaceae plants are more preferred.

[0061] Examples of promoting plant growth include increasing growth rate, increasing the proliferation of plant tissue (including parts of the plant such as fruits and roots), promoting germination, promoting differentiation (e.g., tissue culture of cuttings and other cuttings), increasing the content of inorganic components (e.g., magnesium, phosphorus, potassium, calcium), and improving quality such as the taste of edible parts. In the case of leafy vegetables, this can be confirmed by measuring germination rate, SPAD value, root growth rate, head formation rate, head weight, and outer leaf size. In the case of fruit vegetables where the edible part is the seed (e.g., soybeans, edamame, broad beans), this can be confirmed by measuring plant height, seed yield, and thousand-grain weight.

[0062] [1.4 Optional components] Plant growth promoters may contain components other than ligninsulfonic acid (optional components) as needed. Examples of optional components include plant growth promoters other than ligninsulfonic acid, excipients, colorants, preservatives, pH adjusters, stabilizers, disintegrants, carriers, binders, pH adjusters, defoamers, nonionic surfactants, cationic surfactants, amphoteric surfactants, and other optional components (formulation aids).

[0063] Examples of plant growth-promoting components include inorganic components, silver ions, antioxidants, carbon sources, vitamins, amino acids, plant hormones, and other components that can serve as sources of nutrients for plants. The form of the additive is not particularly limited and may be solid (e.g., powder, granules) or liquid (e.g., liquid fertilizer).

[0064] Examples of inorganic components include essential elements such as nitrogen, phosphorus, and potassium, and trace elements such as inorganic salts of sulfur, calcium, magnesium, iron, manganese, zinc, boron, molybdenum, chlorine, iodine, and cobalt, as well as their oxides, chlorides, sulfur oxides, hydroxides, and carbon oxides. Examples of inorganic components include magnesium hydroxide, magnesium oxide, calcium carbonate (slaked lime), potassium nitrate, ammonium nitrate, ammonium chloride, sodium nitrate, monoammonium phosphate, monopotassium phosphate, dihydrogen phosphate, potassium oxide (salt), potassium chloride, potassium sulfate (sulfur), ammonium sulfate (ammonium sulfate), magnesium sulfate, calcium sulfate, ferrous sulfate, ferric sulfate, manganese sulfate, zinc sulfate, copper sulfate, sodium sulfate, calcium chloride, magnesium chloride, cobalt chloride, boric acid, molybdenum trioxide, sodium molybdate, potassium iodide, monocalcium phosphate, mixtures thereof (for example, superphosphate (a mixture of monocalcium phosphate and calcium sulfate), soluble phosphorus (a mixture of citrate-soluble phosphoric acid and lime, magnesium (magnesium), etc.), phosphorus-nitrate-potassium (a mixture of ammonium nitrate, potassium sulfate, monoammonium phosphate, etc.)), and their hydrates.

[0065] Examples of antioxidants include ascorbic acid and sulfites, with ascorbic acid being preferred. Ascorbic acid has low persistence in the culture medium, thus helping to suppress environmental pollution.

[0066] Examples of carbon sources include compounds such as carbohydrates like sucrose and their derivatives; organic acids like fatty acids; and primary alcohols like ethanol.

[0067] Examples of vitamins include biotin, thiamine (vitamin B1), pyridoxine (vitamin B4), pyridoxal, pyridoxamine, calcium pantothenate, inositol, nicotinic acid, nicotinamide, and riboflavin (vitamin B2).

[0068] Examples of amino acids include glycine, alanine, glutamic acid, cysteine, phenylalanine, and lysine. Examples include inorganic components, organic materials (e.g., compost, oil cake, humic acid and other humic substances), and microbial materials (e.g., yeast). Optional components may be used individually or in combination of two or more. The fertilizer components can be fast-acting, slow-release, or delayed-release fertilizers, and can be inorganic, organic, or chemical fertilizers.

[0069] The amount of each optional ingredient should be selected appropriately.

[0070] [1.5 Dosage form, manufacturing method] The plant growth promoter can be in the form of powder, granules, pellets, or liquid, and is not particularly limited. A granular or pellet form facilitates application. A liquid form facilitates mixing with the functional component, allowing for stabilization of the slurry after mixing. The plant growth promoter may be formulated together with the functional component, or formulated separately. The manufacturing method for the plant growth promoter can be appropriately selected according to the formulation.

[0071] [2. Plant Production Methods] The plant growth stimulants described above can be used in plant production. This can promote plant growth and lead to increased crop yields. The target plants are the same as the examples of target plants described above.

[0072] [Terms of use] The conditions for using the plant growth promoter are not particularly limited. For example, one method is to administer the agent to a support used in plant production and / or to the plant body (e.g., leaves, stems). Examples of support materials include natural soil such as sand and soil; artificial soil such as rice husk charcoal, coconut fiber, vermiculite, perlite, peat moss, glass beads, and rice husks; porous molded products such as foamed phenolic resin and rock wool; and solidifying agents (e.g., agar or gellan gum), with combinations of two or more of these. The administration method depends on the dosage form and the type of support material, but examples include spraying and application (the agent may be mixed with water during irrigation and sprayed), and further mixing treatments such as stirring may be performed as needed. The timing of administration of the plant growth promoter of the present invention is not particularly limited; it may be administered to the support material before use, or added once or multiple times after the start of growth from seedlings or seeds, or both. The dosage of the plant growth promoter of the present invention may be determined appropriately depending on the plant species, timing of application, cultivation conditions, etc., but is usually 0.000001% by weight or more, preferably 0.00001% by weight or more, and more preferably 0.00005% by weight or more, per support (e.g., growing medium), converted to lignin sulfonic acid component. There is no particular upper limit, but it is usually 10% by weight or less.

[0073] Plant growth stimulants may be used in combination with other plant growth stimulants. When used in combination, the plant growth stimulant and the other agent may be mixed and administered simultaneously, or they may be administered separately at appropriate times. Examples of other agents include the fertilizers mentioned above.

[0074] When producing plants using plant growth promoters, the plant cultivation conditions (e.g., temperature, light intensity, type of light (e.g., artificial light, sunlight), light cycle, irrigation volume, humidity, carbon dioxide concentration, whether or not these are adjusted, seeding density, irrigation method, irrigation volume, presence or absence of cultivation facilities / containers (e.g., planters, pots, trays, containers, cell trays)) are not particularly limited and can be selected as appropriate.

[0075] [3. Plant cultivation kit] The plant growth stimulant may constitute a plant cultivation kit together with plant seeds or seedlings. Examples of target plants are given above. Seeds or seedlings should be selected according to the plant species. The cultivation kit may further include a support and a container. Examples of the support and container are given above. [Examples]

[0076] The present invention will be described below with reference to examples. The following examples are not intended to limit the present invention.

[0077] Table 1 shows the compositions of the main samples used in the examples.

[0078] [Table 1]

[0079] [Footnote to Table 1] *1 "%" represents the mass percentage relative to the dry weight of the sample.

[0080] *2 Phenolic hydroxyl group By subtracting the absorption spectrum of a neutral solution containing the same concentration of lignin from the absorption spectrum of an alkaline solution containing a lignin sample, an ionization difference spectrum was obtained, and the phenolic hydroxyl group (%) was determined from the following formula. In the formula, Δαmax [L / (g·cm)] represents the differential extinction coefficient (Junzo Nakano (ed.), "Chemistry of Lignin - Fundamentals and Applications - Revised and Enlarged Edition," Uni Publishing, published May 25, 1990, p. 541). Phenolic hydroxyl groups (%) = (17 × Δαmax) / 4100 × 100

[0081] *3 Carboxylate group A 60 ml aqueous dispersion of 0.5% by mass of the sample was prepared, and a 0.1 M hydrochloric acid solution was added to adjust the pH to 2.5. Then, a 0.05 N sodium hydroxide solution was added dropwise until the pH reached 11, and the electrical conductivity was measured. The amount of sodium hydroxide consumed during the neutralization phase of the weak acid, where the change in electrical conductivity was gradual, was calculated using the following formula (a): Carboxyl group content [mmol / g sample] = a [ml] × 0.05 / sample mass

[0082] *4 Amount of reducing sugars The amount of reducing sugars in the lignin fertilizer was calculated by converting the measured values ​​obtained by the Somogyi-Schaffer method into glucose amounts.

[0083] *5 Methoxyl (OCH3) group content The methoxyl group content of lignin was determined by the Viebock and Schwappach method for the quantitative determination of methoxyl groups ("Lignin Chemistry Research Methods," pp. 336-340, 1994, published by Uni Publishing).

[0084] *6 Total sulfur atom (S) content S content was quantified by ICP emission spectroscopy.

[0085] *7 Sulfur oxide (SO3, SO4) content SO3 and SO4 content were quantified by ion chromatography.

[0086] *8 Sulfur atom (S) content of the sulfone group The sulfur content of the sulfone group was determined by the following formula. S content of sulfone group (mass%) = S content (mass%) - inorganic S content (mass%) In the formula, mass% represents the ratio of the sulfur content to the amount of solid matter in ligninsulfonic acid. The sulfur content is the measured value obtained by the method described above. The inorganic sulfur content is the sum of the SO3 and SO4 content obtained by the method described above.

[0087] *9 Weight average molecular weight (RI) The following conditions were met by gel permeation chromatography (GPC). Measuring device; manufactured by Tosoh Corporation. Columns used: Shodex Column OH-pak SB-806HQ, SB-804HQ, SB-802.5HQ Eluent; 0.05 mM sodium nitrate / acetonitrile 8 / 2 (v / v) Standard substance; polyethylene glycol (manufactured by Tosoh Corporation or GL Sciences Inc.) Detector; differential refractometer (manufactured by Tosoh Corporation) Calibration curve; based on polyethylene glycol

[0088] *10 Weight-average molecular weight (UV) Except for using a UV detector (280 nm, manufactured by Tosoh Corporation) as the detector, the measurement was performed under the same conditions as those for the weight-average molecular weight by the above RI detection.

[0089] *11 Ca content, Na content, Mg content Each metal ion (Ca 2+ , Na + , Mg 2+ ) was quantified by inductively coupled plasma (ICP) method, and the quantification results were respectively converted and calculated into Ca content, Na content and Mg content (mass%).

[0090] <Production Example 1: Production of Sample 1> Wood (radiata pine) was subjected to sulfite treatment based on the sulfite digestion method to obtain an intermediate composition. In the sulfite treatment, a solution of magnesium sulfite with a SO2 concentration of 4 g / 100 mL was used at a temperature of 140 °C, pH 2, and a treatment time of 3 hours. Next, the insoluble matter was filtered off, and the obtained filtrate was concentrated using a rotary evaporator until the solid content reached 50% to obtain an intermediate composition A. Sample 1, which is a solidified composition, was obtained by spray drying.

[0091] <Production Example 2: Production of Sample 2> An alkali reaction (addition rate of calcium hydroxide solution: 9 wt.% (based on solid content), reaction temperature: 90 °C, reaction time: 4 hours) and an oxidation reaction (treatment with oxygen, oxygen pressure: 200 kPa, reaction time: 2 hours) were performed on the intermediate composition A obtained in Production Example 1, and this was adjusted to pH 7.0. Sample 2, which is a solidified composition, was obtained by spray drying this.

[0092] <Production Example 3: Production of Sample 3> An intermediate composition was obtained by sulfurous acid treatment of wood (radiata pine) based on the sulfurous acid pulping method. In the sulfurous acid treatment, a sodium sulfite solution with an SO2 concentration of 4 g / 100 mL was used at a temperature of 140 °C, pH 2, and a treatment time of 3 hours. Next, insoluble materials were filtered off, and the obtained filtrate was adjusted to pH 5.0. This was then subjected to ultrafiltration using a polysulfone-based ultrafiltration membrane with a fractional molecular weight cutoff of 20,000, and the concentrated solution was spray-dried to obtain sample 3, a solidified composition.

[0093] <Manufacturing Example 4: Manufacturing of Sample 4> A lignin-containing substance (Kraft lignin) was prepared from Kraft liquor using conventional methods. Three kilograms of kraft liquor from coniferous trees were placed in a beaker and kept warm at 60°C. Carbon dioxide was blown in under atmospheric pressure while stirring until the pH reached 10. Then, stirring was continued at 80°C for one hour to produce precipitate 3, which was then dehydrated by filtration to obtain a carbonate lignin cake. The obtained lignin carbonate cake was transferred to a beaker, and pure water was added to achieve a solid content concentration of 15% by mass. The mixture was stirred to obtain a homogeneous slurry. While maintaining the temperature at 50°C, 8N sulfuric acid was added while stirring until the pH of the slurry reached 2. The mixture was then stirred at 50°C for 1 hour to produce precipitate 4. The slurry was filtered through a Buchner funnel, and 100 ml of 50°C warm water was added to the obtained lignin cake (precipitate 4). The filtration and washing process was repeated until the electrical conductivity of the filtrate was 0.2 S / m or less to obtain a lignin-containing material. The obtained lignin-containing material was dried in a forced-air dryer at 50°C (solid content concentration: 95% by mass).

[0094] <Manufacturing Example 5: Manufacturing of Sample 5> A lignin-containing substance (soda lignin) was prepared from soda liquor using a conventional method. 200 ml of black liquor from the digestion of rice straw in soda AQ was placed in a beaker and kept warm at 70°C. Carbon dioxide was blown in under atmospheric pressure while stirring until the pH reached 8. After that, stirring was continued at 70°C for 1 hour to produce precipitate 1, which was then dehydrated by filtration to obtain carbonate lignin cake (precipitate 1). The obtained lignin carbonate cake was transferred to a beaker, and pure water was added to achieve a solid content concentration of 15% by mass. The mixture was stirred to obtain a homogeneous slurry. While maintaining the temperature at 50°C, 8N sulfuric acid was added while stirring until the pH of the slurry reached 2. The mixture was then stirred at 50°C for 1 hour to produce precipitate 2. The slurry was filtered through a Buchner funnel, and 100 ml of 50°C warm water was added to the obtained lignin cake (precipitate 2). The filtration and washing process was repeated until the electrical conductivity of the filtrate was 0.5 S / m or less to obtain a lignin-containing material. The obtained lignin-containing material was dried in a forced-air dryer at 50°C (solid content concentration: 95% by mass).

[0095] <Example Test 1: Cultivation Test of Komatsuna (Japanese mustard spinach)> (1) Cultivation using sunlight (Examples 1-2 and Comparative Examples 1-3) Komatsuna (Japanese mustard spinach) seeds (Atariya Farm Komatsuna) were sown on August 23, 2021. The sowing interval was 250 seeds / m 2 Each pot (size: 7L, dimensions: 450mm x 208mm x 170mm) was planted with 20 seeds. The growing medium was prepared by scattering each of the samples shown in Table 2 and other fertilizers onto 5L of soil ("Flower and Vegetable Planter Soil, Planter Cultivation Soil," manufactured by Togawa Heiwa Farm: akadama soil, vermiculite, bark compost) and mixing. The pots were placed indoors in a room with a skylight. The skylight was kept open to allow sunlight in during the growing period. A screen was placed over the skylight to prevent direct sunlight. The indoor temperature was the same as the outdoor temperature. Watering was done when the surface of the soil in the Blank pots was dry (about once every 1-2 days). The amount of water given each time was equal, ensuring that the soil was sufficiently moist, and care was taken to prevent water from directly hitting the leaves and causing them to fall over by using a shower nozzle.

[0096] For each group, four plants were selected from those that germinated on the 14th day after cultivation began. On the 28th day after cultivation began, the SPAD value (Spoil Plant Analysis Development) was measured using a Konica Minolta chlorophyll meter, SPAD-502, as an indicator of chlorophyll content, and the average value was calculated (N=10). On the 42nd day after cultivation began, the root system (the state in which the roots spread horizontally and vertically in the soil) of each individual plant (N=4) was visually observed, and the average plant was evaluated according to the following criteria: ◎ Excellent root system compared to the untreated group, ○ Good root system compared to the untreated group, △ Root system is the same as the untreated group, × Poor root system compared to the untreated group (Table 2). Yield conversion was performed compared to the untreated group (Table 2).

[0097] (2) Cultivation using artificial light (Examples 3-6 and Comparative Examples 4-10) On February 25, 2022, the growing medium was prepared in the same manner as in experiment (1), except that the samples shown in Table 3 were used, and komatsuna seeds were sown. The plants were grown in pots placed by a window indoors, the temperature was set to 20°C, the light cycle was 9 hours of light and 14 hours of dark, and light was irradiated using a plant growth clip lamp manufactured by Fujikura Co., Ltd.

[0098] For each plot, the number of germinated seeds (per 20 seeds) was counted on the 14th day after the start of cultivation. On the 28th day after the start of cultivation, the SPAD value (Spoil Plant Analysis Development) was measured using a Konica Minolta chlorophyll meter, SPAD-502, as an indicator of chlorophyll content, and the average value was calculated (N=10). Also on the 28th day after the start of cultivation, the root development of each individual (N=4) was observed visually and evaluated using the same criteria as in the experiment in (1) (Table 3).

[0099] [Table 2]

[0100] [Table 3]

[0101] [Footnotes for Tables 2 and 3] *1 The amounts of phosphorus, nitrogen, and potassium are given as weight percent relative to the sample added to the growing medium. *2 In Comparative Examples 2 and 5, commercially available fertilizers used were Hachipara Ace (slow-release fertilizer, P10, N10, K10, magnesium 1), manufactured by Toyochu. *3 In Comparative Examples 3, 9 and 10, and Examples 2 and 6, yeast (Cyperus rotundus, manufactured by Nippon Paper Industries Co., Ltd.) was used. *4 In Examples 2 and 6, the ratio of yeast to sample 1 (by weight) was set to 9.78:10 in order to match the nitrogen content with the commercially available fertilizer. *5 In Comparative Example 10, the yeast:lignin (weight ratio) was set to 9.78:10 to match the amount added in Example 6.

[0102] In both cultivation tests using sunlight and artificial light, the examples showed better root development compared to the comparative examples. Furthermore, each example exhibited high SPAD values ​​(Tables 2 and 3).

[0103] <Test Example 2: Cultivation Test of Chinese Cabbage (Examples 7-9 and Comparative Examples 11-15)> On August 19th, I planted Chinese cabbage (variety: Matsushima Shin-2) seeds in open-field pots (size: 1 / 2000a = 0.05m). 2 Three seeds were sown per pot in 1 / 2000a Wagner pots (manufactured by Tokyo Glass Machinery Co., Ltd.). The growing medium was prepared by spreading and mixing each of the samples shown in Table 4 and other fertilizers onto soil (alluvial deposits, sandy loam). Cultivation was carried out outdoors.

[0104] For each plot, the harvest was carried out on November 20 of the same year, and the yield, the amount of MgO contained in the Chinese cabbage, the weight of the head, the outer leaves, and the head formation rate were measured. For each measurement value, an index was calculated with the sample without additives (Comparative Example 11) set to 100 (Table 5).

[0105] [Table 4]

[0106] [Footnote to Table 4] *1 MgO refers to the amount of MgO contained in each sample, and was measured by the following method: 2.5-5 g of the analytical sample was accurately placed in a tall beaker, approximately 30 ml of hydrochloric acid and approximately 10 ml of nitric acid were added, and the mixture was boiled for approximately 30 minutes. After cooling, water was added to make a total volume of exactly 250-500 ml, and the mixture was filtered through dry filter paper. A certain amount of the sample solution (preferably 50-500 μg as Mg, or 80-800 μg as MgO) was accurately placed in a 100 ml volumetric flask, and 10 ml of interference suppressant solution (60.9-152.1 g of strontium chloride (SrCl2·6H2O) was dissolved in 420 ml of water and hydrochloric acid to make 1000 ml; or 53.5 g of lanthanum chloride (LaCl3·7H2O) was used instead of strontium chloride) was added. After that, water was added to the mark, and the absorbance at a wavelength of 285.2 nm was measured using an atomic absorption spectrometer. Simultaneously, standard magnesium solution was accurately measured in several stages, and interference suppressant solution was added to each to the same concentration as the sample solution. The amount of magnesium (Mg) or magnesium oxide (MgO) was then determined from the calibration curve created by photometry under the same conditions.

[0107] [Table 5]

[0108] [Footnote to Table 5] *1 Head weight (g) is the average weight of the formed head of Chinese cabbage. *2 MgO (unit: mg) represents the MgO content (%) in Chinese cabbage, and was measured using the following method: 10 to 20 plants of average size were selected and collected from the field. Medium to large plants were divided lengthwise into 4 to 8 sections, and one section was taken from each section. Approximately 20 small plants were taken. The leaves were then removed and spread out for ventilation and drying. Inner and outer leaves were separated as needed. After drying, the plants were ground using a Wiley-type or coffee mill-type grinder to obtain powder samples, which were then measured in the same manner as the MgO measurement method described above. *3 Outer leaf (cm) is the maximum leaf length of the outer leaves (N=3). *4 The head formation rate (%) is the ratio of head-forming individuals to the total number of individuals.

[0109] Examples 7-9 had higher MgO content and larger outer leaves compared to the comparative example. In particular, Examples 7 and 9 showed good yield and head weight, and Example 7 also had a high head formation rate (Table 5).

[0110] <Test Example 3: Soybean Cultivation Test (Examples 10-13 and Comparative Examples 16-20)> On June 29th, 258 soybean (variety: Tachisuzunari) seeds were sown (sowing interval: 20 seeds / m²). 2 , 10a = 1000m per section 2 The plants were grown in open fields. The growing medium was prepared by spreading each of the samples shown in Table 6 (including commercially available fertilizers) onto soil (from Ibaraki Prefecture) and mixing them. The plants were harvested on October 15 of the same year, and the plant height, grain yield, and thousand-grain weight were measured for each plot. For the grain yield, an index was calculated with the sample without additives (Comparative Example 16) set to 100 (Table 7).

[0111] [Table 6]

[0112] [Footnote to Table 6] *1 The amounts of N, P2O5, and K2O added are the amounts of each component added relative to the total amount of commercially available fertilizer (manufactured by Sun & Hope, containing ammonium sulfate, superphosphate, and potassium sulfate; N: 21% ammonium sulfate, P2O5: 16.5% superphosphate, and K2O: 50% potassium sulfate) added to all groups, and the sample used in each group. *2 MgO refers to the amount of MgO contained in each sample, and was measured in the same manner as the MgO measurement method in Test Example 2.

[0113] [Table 7]

[0114] [Footnote to Table 7] *1 Grass height (cm) is the height from the ground surface to the top (N=4). *2 Grain weight (g / m 2=kg / 10a) is the weight of grain per plot (10a) (N=1). *3 The thousand-grain weight (unit: g) is the average weight of 1,000 seeds (N=1).

[0115] Compared to Comparative Example 16 (no additives, standard group), the harvested soybean grains or bamboo shoots were larger in each of the examples. In particular, Example 10 showed a high thousand-grain weight.

[0116] <Test Example 4: Calcium Carbonate Dispersion Test (Type B Viscosity Test) (Example 14, Comparative Examples 21-24)> We evaluated the effect of calcium carbonate, used as a bulking agent in pesticides, on dispersibility. A slurry was prepared by adding 37.56 g of water and each of the dispersants shown in Table 8 to 172.44 g of calcium carbonate (water content 30%) and stirring. The slurry concentration of water and calcium carbonate was 57%, and the amount of dispersant added (solid content addition rate) was 0.05 or 0.1% of the total slurry volume. Stirring was performed with a homodisper at 3000 rpm for 2 minutes. The B-type viscosity of the slurry after stirring was measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.) under the conditions of 20°C, 60 rpm, No. 3 rotor or No. 2 rotor, and no guard (Table 8).

[0117] [Table 8]

[0118] Since Example 14, using sample 3, had a lower viscosity than water alone or Comparative Examples 21-24, using samples 4-6, it became clear that the plant growth promoter of the present invention exhibits good dispersibility, is retained in the culture medium, and can improve the dispersibility of fertilizer components and pesticide components.

[0119] <Test Example 5: Fertilizer Efficacy Test Using Sample 1 (Examples 15-25, Comparative Examples 25-27)> (1) Onion Yellow onions (Kaizuka Wase variety) were sown in seedbeds on September 16th, and the main ears were planted in soil (reddish-yellow soil derived from beach sediment, 13.1m in each plot) on November 18th of the same year. 2 The plants were planted in two rows of 3.75 x 3.5 m plots. The planting conditions were a ridge width of 75 cm, two rows planted, a plant spacing of 12 cm, and a planting density of 2222 plants / a. As common fertilizers, Kumiai Chemical No. 11 (N, P2O5, K2O) 2 kg / a, F·T·E (B9%, Mn19%) 0.4 kg / a, and humic acid PVA were used. In addition, the fertilizers listed in Table 9 were added to each plot. The harvest was carried out on June 3 of the following year, and the yield was measured (Table 10).

[0120] [Table 9]

[0121] [Table 10]

[0122] [Footnote to Table 10] Table 10 shows the 1.8m m with few missing plants. 2 The results of the yield survey regarding this matter are shown.

[0123] (2) Wheat On November 14th (the day of sowing), soil was placed in the lower layer of the pot (up to 20 cm from the pot opening), then the lignin sample (Sample 1) was placed on top in the amounts shown in Table 11 (up to 10 cm from the pot opening), and then soil was placed on top again to prepare the pots for the middle layer treatment. Separately, on November 4th (10 days before sowing) and 14th (the day of sowing), soil was placed in the middle layer of the pot (up to 10 cm from the pot opening), and then the lignin sample was placed on top in the amounts shown in Table 11 (up to the pot opening) to prepare the pots for the top layer treatment. In addition, 2.0 g of N (ammonium sulfate), 1.0 g of P2O2 (superphosphate or fused phosphate), and 1.0 g of K2O (hydrochloride) were applied as common feed to each treatment group. For each treatment plot, wheat (Wheat Norin No. 50) was sown on November 14th in three pots (four seeds per pot). Then, on December 15th of the same year, the seedlings were thinned to leave three plants per pot, and the wheat was harvested on June 15th of the following year after maturation (Table 11).

[0124] [Table 11]

[0125] [Notes on Table 11] Table 11 shows the average values ​​(amount of air-dried material per pot) for three rows in one section.

[0126] <Test Example 6: Fertilizer Efficacy Test Using Sample 2 (Examples 26-45, Comparative Examples 28-43)> (1) Cucumbers and eggplants On May 9th, cucumber seedlings (four-leaf cucumber, 4 true leaves, 8cm tall) and eggplant seedlings (first-generation hybrid Takano early-maturing medium eggplant, 5 true leaves, 18cm tall) were transplanted into soil (alluvial sandy loam) (3.3m per plot). 2 Six plants were planted per plot, and their growth was observed over time. Humic acid PVA was used as a common fertilizer, and the fertilizers listed in Table 12 were added to each plot. Growth surveys and yield measurements were conducted over time (Tables 13, 14: N=3).

[0127] [Table 12]

[0128] [Table 13]

[0129] [Table 14]

[0130] [Footnotes to Tables 13 and 14] The growth rate is the average growth rate (cm) per plant in each section. The numbers in parentheses for growth quantity indicate the number of leaves for cucumbers and the number of branches for eggplants. The yield is the total amount (g) of 3 plants in each plot. The number in parentheses for yield indicates the number of individuals.

[0131] (2) Melon The melons (Earl's variety, Nan'en No. 2) were divided into 3 sections (Table 15), with each section measuring 1m² in the greenhouse. 2 A cultivation trial was conducted in a single row. Seeds were sown in soil (diluvial loam) on June 8, transplanted on June 15, and permanently planted (with 4 true leaves) on July 2. Subsequently, pinching (July 18), pollination (July 21-26), fruit thinning (July 29), suspension (July 30), and bagging (August 7) ​​were carried out sequentially, and harvesting took place on September 4. For each plot, the fertilizers shown in Table 15 and common fertilizers (humic acid, PVA-based) were applied on July 2 for the first time (base fertilizer), the second time (first top dressing) immediately after fruit thinning, and the third time (second top dressing) when the netting began to emerge. Watering was performed twice before pollination and three times after pollination. Daisen and Karasen were sprayed seven times as fungicides and disinfectants. Temperature and humidity were controlled as follows: seedling stage: 30°C during the day and 22°C at night; vegetative growth stage: 32°C during the day and 25°C at night, with 75% nighttime humidity; fruiting stage: 32°C during the day and 24°C at night, with 94% nighttime humidity; harvest stage: windows were opened to reduce humidity. Yield was measured and fruit was evaluated (Tables 16 and 17).

[0132] [Table 15]

[0133] [Table 16]

[0134] [Table 17]

[0135] (3) Corn Soil (either of the following: topsoil from the alluvial soil of the Kofu Basin or subsoil from the brown volcanic ash soil of the Yatsugatake Mountains) was placed in Wagner pots 1 / 2000a (3 rows), and green corn was sown on June 28th and fertilized (Table 18). Growth was monitored over time, and harvesting took place on August 12th.

[0136] [Table 18]

[0137] [Footnote to Table 18] The three elements, CaCO3, lignin (sample 2), and compost were each mixed throughout the entire layer from 0 to 10 cm. The fertilizer applied is as follows: ammonium sulfate 21%, superphosphate 19.5%, potassium sulfate 50%; compost components: N 0.59%, P2O 50.23%, K2O 0.66% deducted; lignin, magnesium, MgO 5.0%

[0138] [Table 19]

[0139] [Table 20]

[0140] (4) Cub Soil (either of the following: topsoil of alluvial soil from the Kofu Basin or subsoil of brown volcanic ash soil from the Yatsugatake Mountains) supplemented with lignin (sample 2) was placed in Wagner pots 1 / 2000a. Small turnips (Someya Kanemachi) were sown on April 30 and fertilized (Table 21). Disinfection was carried out on May 20 and 30, and weeding was done on June 7. Growth was monitored periodically throughout the cultivation period (Table 22), and the crops were harvested on June 11 and the yield was investigated (Table 23).

[0141] [Table 21]

[0142] [Table 22]

[0143] [Table 23]

[0144] (5) Upland rice Rice (Upland rice Norin No. 1 (mochi)) was planted in diluvial soil (alluvial soil) with a planting density adjusted to 30 grains per row for two rows. Sowing and fertilization were carried out on May 13 (Table 24), and the rice was harvested on November 4 of the same year, followed by a growth survey (Table 25).

[0145] [Table 24]

[0146] [Footnote to Table 24] Compound fertilizer: N 1.0kg / 10a, P2O 5 1.0kg / 10a, K2O 0.8kg / 10a (Kumiai Phosphorus, Nitrogen, Ammonium, Potassium: N 15.0%, P 15.0%, K 12.0%) Lignin Magnesium Oxide (MgO) 5.0%

[0147] [Table 25]

[0148] (6) Summer carrots The soil was tilled to a depth of 15 cm, and common fertilizer and the fertilizers shown in Table 26 were applied to the fertilization furrows. Ridges were made with a width of 60 cm (13.1 m per plot). 2 Carrots (Kuroda Gosun carrots) were sown (two rows) on a 3.75m x 3.5m plot on June 11th. The plants were thinned to a spacing of 15cm, resulting in approximately 2220 plants / a. When the soil moisture tension at a depth of 10cm within the furrow exceeded pF2.5, watering was performed with 20-30mm at a time, for a total of 180mm. The carrots were harvested on September 16th, and the yield, component content, and nutrient absorption of the harvested produce were measured (Tables 27 and 28).

[0149] [Table 26]

[0150] [Table 27]

[0151] [Table 28]

[0152] (7) Autumn-grown carrots Common fertilizers and the fertilizers shown in Table 29 were applied to the soil (fine-grained soil poor in humus, derived from unconsolidated Pleistocene sediments) (August 2nd). Ridges were constructed with a width of 60 cm (9 m per plot). 2 Carrots (Kuroda Gosun carrots) were sown (two rows) on September 1st in a 3m x 3m plot (3 rows). The plants were thinned to a spacing of 15cm, resulting in approximately 2220 plants / a. When the soil moisture tension at a depth of 10cm within the furrow exceeded pF2.5, watering was performed with 10-20mm of water at a time, for a total of 220mm. The plants were harvested on January 6th of the following year, and growth was surveyed and nutrient absorption was measured (Table 30).

[0153] [Table 29]

[0154] [Table 30]

[0155] <Test Example 7: Fertilizer efficacy test using calcium ligninsulfonate (Examples 46-49, Comparative Examples 44-47)> (1) Onion Yellow onions (Senshu Yellow Onions) were sown in a seedbed on September 6th, and the main ears were transplanted into soil (Kofu Basin alluvial soil, loam) on November 10th. The transplanting conditions were a ridge width of 100cm, 4 rows planted, 18cm between plants, and 12cm between plants. Fertilization was carried out using the fertilizers listed in Tables 31 and 32 (also treated with nitrohumic acid PVA, etc.) as base fertilizer on November 6th, and as top dressing on February 23rd, March 28th, and April 16th of the following year. Harvesting took place on July 9th, and the yield was measured (Table 33).

[0156] [Table 31]

[0157] [Table 32]

[0158] [Table 33]

[0159] (2) Paddy rice On June 26th, rice (Pi5) seedlings were planted in paddy fields (paddy field soil: granitic sandy loam, 10m per plot). 2 Three plants were planted per area (3m x 3.35m) (planting density: 1m 2 The number of plants per field was 32 (25cm x 12.5cm). Fertilizers shown in Table 34 were applied at each stage. Heading occurred on September 2nd, after which pesticides such as diazinon, PCP, and fumilon were sprayed. Harvesting took place on October 31st, and growth surveys and phosphorus and potassium content were measured (Tables 35 and 36).

[0160] Table 34

[0161] Table 35

[0162] Table 36

Claims

1. The proportion of sulfur atoms derived from sulfone groups to the total sulfur atom content in ligninsulfonic acid is 0.5 or more. Calcium atom content of 0.001% by weight or more, The sodium atom content is 0.3% by weight or more, A plant growth promoter containing a lignin sulfonic acid component with a magnesium atom content of 0.05% by weight or more.

2. Lignin sulfonic acid component, The reducing sugar content is 30% by weight or less. The sulfur atom content derived from the sulfone group is 3.0% by weight or more, and The phenolic hydroxyl group content must be 0.5% by weight or more. The agent according to claim 1, which satisfies at least one of the following conditions.

3. The agent according to claim 1 or 2, wherein the carboxyl group content of the lignin sulfonic acid component is 0.3 to 4.0 mmol / g.

4. The agent according to claim 1 or 2, wherein the weight-average molecular weight (RI) of the lignin sulfonic acid component is 3,000 or more.

5. The agent according to claim 1 or 2, wherein the lignin sulfonic acid has substituents derived from (poly)alkylene oxide.

6. A method for producing plants, comprising cultivating plants using the agent described in claim 1 or 2.

7. A plant cultivation kit comprising the agent according to claim 1 or 2, and plant seeds or seedlings.

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