Plant growth promoter

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] The present invention relates to a plant growth promoter. [Background technology]

[0002] Lignin is a high molecular weight phenolic polymer contained in plant tissue. When plants are decomposed by soil microorganisms, lignin decomposition products are generated as intermediate products, and the lignin decomposition products combine with peptides and amino acids produced by the decomposition of microbial proteins to produce humic acid. Humic acid promotes plant growth, improves the fertility retention of soil, and activates soil microorganisms. For this reason, lignin has been used to promote the growth of plants such as agricultural crops.

[0003] Patent Document 1 describes a plant vitalizing agent containing, as an active ingredient, a lignin decomposition product that has an aldehyde yield of 10 mass % or more as a result of alkaline nitrobenzene oxidation.

[0004] Patent Document 2 describes a plant growth promoter that contains granular plant seed husk components that contain 40% by mass or more and 60% by mass or less of lignin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-190331 A [Patent Document 2] International Publication No. 2019 / 078209 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in order to further utilize lignin, there has been a demand for the development of a lignin derivative that can exert a higher growth-promoting effect on plants than the agents of Patent Documents 1 and 2. However, there have been cases where the yield has not been sufficiently improved. The present invention has been made in view of the above, and aims to provide a plant growth-promoting agent that contains a lignin compound as an active ingredient and 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 comprising 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 derived from sulfonic groups of 2.0% or more. [2] Lignosulfonic acid components, The reducing sugar content is 35% by weight or less. The sulfur atom content is 3.0% by weight or more, and The sodium atom content is 0.3% by weight or more. The agent according to [1], which satisfies at least one of the above. [3] The agent according to [1] or [2], wherein the carboxyl group content of the lignosulfonic acid component is 0.1 to 4.5 mmol / g. [4] The agent according to any one of [1] to [3], wherein the weight average molecular weight (RI) of the lignosulfonic acid component is 3,000 or more. [5] The agent according to any one of [1] to [4], wherein the lignin sulfonic acid has a substituent derived from a (poly)alkylene oxide. [6] A method for producing a plant, comprising cultivating a plant using the agent according to any one of [1] to [5]. [7] A plant cultivation kit comprising the agent according to any one of [1] to [5] and a plant seed or seedling. Effect of the Invention

[0008] According to the present invention, there is provided a plant growth-promoting agent capable of promoting the growth of various plants. The plant growth-promoting agent of the present invention can be applied regardless of the growing season or cultivation conditions of the plant, and therefore can lead to increased production and yield of crops in the agricultural field. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [1. Lignosulfonic acid components] The plant growth promoter of the present invention contains a lignosulfonic acid component.

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

[0011] Lignosulfonic acid may take the form of a salt, such as a monovalent metal salt, a divalent metal salt, an ammonium salt, or an organic ammonium salt, of which calcium salt, magnesium salt, sodium salt, or a mixed calcium-sodium salt is preferred.

[0012] [Substituent] Lignosulfonic acid contains a substituent other than a sulfone group. The substituent may be a substituent derived from lignin, or may be a substituent that is introduced by modification treatment and is not originally contained in lignin. Examples of the substituent include a hydroxyl group (phenolic hydroxyl group, alcoholic hydroxyl group), a methoxyl group, a carboxyl group, a sulfomethyl group, an aminomethyl group, and a (poly)alkylene oxide group. Of these, it is more preferable to contain a phenolic hydroxyl group, a methoxyl group, a sulfone group, and a (poly)alkylene oxide group in a predetermined range. This can promote plant growth.

[0013] -Phenol hydroxyl group- The phenolic hydroxyl group is generally a hydroxyl group directly bonded to an aromatic ring 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 the lignosulfonic acid component. 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 the lignosulfonic 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 measured by a spectrophotometer.

[0014] -Methoxyl group- The 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 the lignosulfonic acid component. 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 method.

[0015] -Sulfonic acid group- A sulfone group (sulfonic acid group, sulfo group) is generally represented by the formula: -SO3 - M +(M is a counter cation (e.g., H, Na, Ca, Mg, NH4)). The sulfonic group content can be represented by the content of sulfur atoms derived from sulfonic groups (sulfonic group S content). The sulfonic 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, based on the total amount of the lignosulfonic acid component. 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 sulfonic 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 sulfonic group S content can be determined by subtracting the inorganic sulfur atom content from the total sulfur atom content in the lignosulfonic acid.

[0016] -Carboxyl group- A carboxyl group generally has the formula: -COOM + (M is a counter cation (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, more preferably 0.3 mmol / g or more, and even more preferably 0.5 mmol / g or more, per weight of the lignosulfonic acid component. 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 a (poly)alkylene oxide. The average number of moles added of the 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 improve the dispersibility. Among them, it is preferable that the number is 50 or more, 60 or more, 70 or more, 80 or more, or 90 or more, because the water surface spreadability is further improved. 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 the decrease in dispersion retention. Therefore, the average number of moles added 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 may be preferably 25 to 300, more preferably 30 to 200, and even more preferably 35 to 150. The number of carbon atoms of the polyalkylene glycol is not particularly limited, and is usually 2 to 18, preferably 2 to 4, and more preferably 2 to 3. Examples of the alkylene oxide unit include an ethylene oxide unit, a propylene oxide unit, and a butylene oxide unit, and an ethylene oxide unit or a propylene oxide unit is preferable. Examples of lignin sulfonic acids containing a (poly)alkylene oxide group include lignin derivatives described in WO 2021 / 066166.

[0018] [Inorganic components] The lignosulfonic acid component may further contain an inorganic component. Examples of the inorganic component include inorganic salts of sulfur, calcium, sodium, magnesium, nitrogen, phosphorus, potassium, iron, etc., 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), carbonates (e.g., calcium carbonate, sodium carbonate), and nitric acid. The form of the inorganic component is not particularly limited, and may be a counter cation of lignosulfonic acid or a free inorganic component (e.g., an inorganic component added during the production of lignosulfonic acid). Of these, it is preferable to contain at least one of sulfur, calcium, sodium, magnesium, nitrogen, phosphorus, and potassium.

[0019] -Sulfur ion- The content of sulfur ions can be expressed as the content of sulfur atoms (total S content) contained in lignosulfonic 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 atomic emission spectrometry.

[0020] -Sulfur oxide- Lignosulfonic acid may contain sulfur oxide. Examples of sulfur oxide include sulfur dioxide (SO2), sulfur trioxide (SO3), and sulfur tetroxide (SO4), and SO3 and SO4 are 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, since SO3 may change to the SO4 form. 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] -Proportion of sulfonic S in the total S content- The ratio of the sulfur atom content derived from sulfonic groups to the total sulfur atom content in lignosulfonic acid is preferably 0.5 or more, more preferably 0.6 or more, and the upper limit is usually 0.95 or less, preferably 0.9 or less, but is not particularly limited.

[0022] -The ratio of SO3 to SO4- The ratio of the SO3 content to the SO4 content in lignosulfonic acid is usually 0 or more, preferably 0.01 or more, and more preferably 0.02 or more. 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+ Each ion content 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 limit to the 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 further 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 content, Ca content, and Mg content can be quantitatively determined by an inductively coupled plasma (ICP) method.

[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 generating aldehyde groups or ketone groups in a basic solution. Examples of reducing sugars include all monosaccharides; disaccharides such as maltose, lactose, arabinose, and invert sugars of sucrose; and polysaccharides. Reducing sugars generally include cellulose, hemicellulose, and their decomposition products. Examples of decomposition products of cellulose and hemicellulose 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 of such modified products 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 of the sugar derivatives (two types) are bonded.

[0025] The reducing sugar content is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.5% by weight or more, or 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, and even more preferably 0.5 to 25% by weight, or 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 lignosulfonic acid component may contain components other than those mentioned above. For example, organic components and ash may be mentioned. Examples of the organic components include low molecular weight organic substances (for example, organic acids having 5 or less carbon atoms) such as formic acid, acetic acid, propionic acid, valeric acid, pyruvic acid, succinic acid, and lactic acid.

[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. The upper limit is not particularly limited, but 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 lignosulfonic 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. The upper limit is not particularly limited, but 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 a 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 the weight average molecular weight (RI) to the weight average molecular weight (UV) is preferably 0.95 or less, more preferably 0.93 or less. The lower limit is usually 0.4 or more, preferably 0.5 or more, and is not particularly limited.

[0030] As the lignin sulfonic acid component, for example, one having the above-mentioned substituents and inorganic component amounts may be selected from Sanlighon (scheduled to be sold by Nippon Paper Industries Co., Ltd. after July 2022) and used.

[0031] [1.2 Method for producing lignosulfonic acid components] The method for producing the lignosulfonic acid component is not particularly limited, but it can be produced, for example, by a method of subjecting a lignocellulose raw material to a sulfite treatment, or a method of decomposing lignin and sulfonating it. By adjusting the production conditions, it is possible to adjust the type and content of the substituents possessed by the lignosulfonic acid component, and the type and content of each component such as inorganic components and reducing sugars.

[0032] -Raw materials- Lignocellulose raw materials as an example of raw materials are not particularly limited as long as they contain lignocellulose in the constituents. For example, pulp raw materials such as wood and non-wood can be mentioned. For example, wood can be coniferous wood such as radiata pine, Yezo spruce, red pine, cedar, and cypress, and broadleaf wood such as white birch and beech. The age of the wood and the part from which it was harvested do not matter. Therefore, wood harvested from trees of different ages or wood harvested from different parts of a tree may be used in combination. For example, non-wood can be bamboo, kenaf, reed, and rice. The lignocellulose raw materials may be one type alone or two or more types in combination.

[0033] Other examples of lignin as the raw material include naturally occurring lignin and artificially produced lignin (for example, dehydrogenation polymerized product of hydroxycinnamic alcohol analogues).

[0034] -Sulfurous acid treatment- The sulfite treatment can be carried out by contacting the lignocellulosic raw material with at least one of sulfurous acid and a sulfite salt. The conditions for the sulfite treatment are not particularly limited as long as they allow introduction of a sulfo group to the α-carbon atom of the side chain of lignin contained in the lignocellulosic raw material.

[0035] The sulfite treatment is preferably carried out by sulfite cooking, which allows the lignin in the lignocellulosic raw material to be sulfonated more quantitatively. The sulfite cooking is a method in which the lignocellulosic raw material is reacted at high temperature in a solution of at least one of sulfurous acid and a sulfite salt (e.g., aqueous solution: cooking liquid). This method has been established and is being carried out industrially as a method for producing sulfite pulp, and is therefore advantageous in terms of economy and ease of implementation.

[0036] When sulfite cooking is carried out, examples of the sulfite salt 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 mass (g) of SO2 to 100 mL of reaction solution is preferably 1 g / 100 mL or more, and more preferably 2 g / 100 mL or more when sulfite cooking is performed. The upper limit is preferably 20 g / 100 mL or less, and more preferably 15 g / 100 mL or less when sulfite cooking is performed. The SO2 concentration is preferably 1 g / 100 mL to 20 g / 100 mL, and more preferably 2 g / 100 mL to 15 g / 100 mL when sulfite cooking is performed.

[0038] The pH value of the sulfurous acid treatment is not particularly limited, but is usually 10 or less. When sulfurous acid cooking is performed, it is preferably performed under acidic conditions, more preferably pH 5 or less, and even more preferably pH 3 or less. This allows lignin derivatives (e.g., lignin sulfonic acid) to be efficiently extracted, and pulp of higher quality can be obtained. The lower limit of the pH value is preferably 0.1 or more, and when sulfurous acid cooking is performed, it is more preferably 0.5 or more. The pH value during the sulfurous acid treatment is preferably 0.1 to 10, and when sulfurous acid cooking is performed, it is more preferably 0.5 to 5, and even more preferably 0.5 to 3.

[0039] The temperature of the sulfite treatment is not particularly limited, but is preferably 170° C. or lower, and more preferably 150° C. or lower when sulfite cooking is performed. The lower limit is preferably 70° C. or higher, and more preferably 100° C. or higher when sulfite cooking is performed. The temperature condition of the sulfite treatment is preferably 70 to 170° C., and more preferably 100 to 150° C. when sulfite cooking is performed. The treatment time for the sulfurizing treatment is not particularly limited, and although it depends on the conditions of the sulfurizing treatment, it is preferably 0.5 to 24 hours, and more preferably 1.0 to 12 hours.

[0040] In the sulfite treatment, it is preferable to add a compound that supplies a counter cation to the lignosulfonic acid. By adding a compound that supplies a counter cation, the pH value in the sulfite treatment can be kept constant. Examples of compounds that supply counter cations include MgO, Mg(OH)2, CaO, Ca(OH)2, CaCO3, NH3, NH4OH, NaOH, NaHCO3, and Na2CO3. The counter cation is preferably a magnesium ion or a sodium ion.

[0041] In the sulfurous acid treatment, when a solution of at least one of sulfurous acid and sulfite is used, the solution may contain, in addition to SO2, the above-mentioned counter cation (salt) and a digestion and penetration agent (e.g., a cyclic ketone compound such as anthraquinone sulfonate, anthraquinone, or tetrahydroanthraquinone), as necessary.

[0042] There is no limitation on the equipment used in the sulfite treatment, and for example, generally known dissolving pulp manufacturing equipment can be used.

[0043] The intermediate product may be separated from the solution of at least one of sulfurous acid and sulfite salts by a conventional method, such as a method for separating the sulfurous acid digestion wastewater after the sulfurous acid digestion (e.g., filtration).

[0044] The lignosulfonic acid obtained by the sulfite treatment (e.g., as the filtrate or filtration residue after filtering insoluble matters in a sulfite solution, preferably as the filtrate) may be used as the lignosulfonic acid component, which is an active ingredient, either as is or after concentrating as necessary. On the other hand, if necessary, other treatments may be further carried out. This can increase the purity or introduce other substituents that are not inherently contained in the raw material. Examples of other treatments include alkali treatment, oxidation treatment, dialysis treatment, ultrafiltration treatment, modification treatment, and combinations of these.

[0045] (Alkaline treatment) The alkaline treatment can be carried out by placing the target sample under alkaline conditions. Placing the sample under alkaline conditions usually means placing the sample in an aqueous solution having a pH value of 8 or more, preferably a pH value of 9 or more. The upper limit of the pH value is usually 14.

[0046] In the alkali treatment, an alkaline substance is usually brought into contact with the sulfite treatment product. The alkaline substance is not particularly limited, but examples thereof 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 a method for contacting an alkaline substance with the sulfurous acid treated product include a method of preparing a dispersion or solution (e.g., an aqueous dispersion or aqueous solution) of the sulfurous acid treated product and adding an alkaline substance to the dispersion or solution, and a method of adding a solution or dispersion (e.g., an aqueous dispersion or aqueous solution) of the alkaline substance to the sulfurous acid treated product.

[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 the alkaline substance in the alkali treatment is preferably 0.5 to 40 mass %, more preferably 1.0 to 30 mass %, based on the solids mass of the sulfurous acid treated product, or, when an aqueous solution or dispersion is prepared by dispersing the alkali treated extract in an aqueous solvent (e.g., water), based on the mass of the aqueous solution or dispersion.

[0050] The time for the alkali treatment is not particularly limited, but is preferably 0.1 hours or more, more preferably 0.5 hours or more, and is preferably 10 hours or less, more preferably 6 hours or less.

[0051] Prior to the alkali treatment, the sulfite-treated product may be dissolved, dispersed, or the concentration adjusted (preparation of a solution or dispersion in an aqueous solvent such as water) as necessary. Dispersion can be performed by passing through a disc refiner, adding to a mixer or disperser, kneading, or the like. The concentration can be adjusted, for example, by using an aqueous solvent such as water.

[0052] (Oxidation treatment) The oxidation treatment can be carried out on the treated product obtained after the sulfurous acid treatment (for example, the filtrate after filtration) or the treated product after the alkali treatment. The oxidation treatment can be carried out by using an appropriate oxidizing agent. When the oxidizing agent is a gas, the oxidation treatment can be carried out by bubbling the gas into the filtrate. When the oxidizing agent is a liquid, the oxidation treatment can be carried out by adding the liquid to the filtration residue or the 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 (alkaline oxidation treatment). The treatment pH of the alkaline oxidation treatment is usually 8 or more, preferably 10 or more, and more preferably 12 or more. The temperature of the oxidation treatment is usually 20 to 200°C, and preferably 50 to 180°C. The time of the oxidation treatment is usually preferably 0.1 hours or more, and 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 or UF treatment) The dialysis treatment can be performed on the treated product obtained after the sulfite treatment (for example, the filtrate after filtration). Examples of the dialysis membrane include cellulose-based membranes such as cellulose acetate, and synthetic polymer-based membranes such as ethylene vinyl alcohol, polyacrylonitrile, polymethyl methacrylate, polysulfone, and polyethersulfone, and 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] Instead of dialysis, ultrafiltration (UF) can be used. As the UF membrane, a known UF membrane can be used. For example, a hollow fiber membrane, a spiral membrane, a tubular membrane, and a flat membrane can be used. As the material of the UF membrane, a known material can be used. For example, cellulose acetate, aromatic polyamide, polyvinyl alcohol, polysulfone, polyvinylidene fluoride, polyethylene, polyacrylonitrile, and ceramic can be used. The UF membrane may be a commercially available product.

[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. When a UF membrane with a molecular weight cutoff of 5,000 or more is used, it is possible to prevent the separation speed of the treatment liquid from being excessively slowed. In addition, when a UF membrane with a molecular weight cutoff of 30,000 or less is used, it is possible to prevent lignin from being unable to be separated from the treatment liquid.

[0056] The concentration ratio by the UF treatment using the UF membrane can be set arbitrarily. In other words, the UF treatment can be stopped when the outflow amount of the concentrated liquid reaches an arbitrary amount. It is preferable to concentrate 2 to 6 times. Concentrating 2 to 6 times means that the amount of the raw liquid (black liquor) becomes 1 / 2 to 1 / 6.

[0057] The temperature of the treatment liquid during UF treatment is not particularly limited. For example, it is preferably 20 to 80°C, and more preferably 20 to 70°C in consideration of the heat resistance of the UF membrane material. The pH value of the treatment liquid 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%, more preferably 5 to 20%.

[0058] Examples of the modification treatment include chemically modified methods such as hydrolysis, alkylation, alkoxylation, sulfonation, sulfonate esterification, sulfomethylation, aminomethylation, desulfonation, alkalization, and condensation reaction with (poly)alkylene oxide; and a method of molecular weight fractionation of lignosulfonic acid by ultrafiltration. Of these, the chemically modified method is preferably one or more reactions selected from hydrolysis, alkoxylation, desulfonation and alkylation, and condensation reaction with (poly)alkylene oxide (e.g., WO 2021 / 066166).

[0059] [1.3 Plant growth promotion effect] The lignin sulfonic acid component has the effect of promoting plant growth.

[0060] [plant] Target plants include herbaceous plants and woody plants, such as Brassicaceae, Fabaceae, Cucurbitaceae, Solanaceae, Capsicum, Rosaceae, Malvaceae, Poaceae, Liliaceae, Amaryllidaceae, Asteraceae, Amaranthaceae, Umbelliferae, Zingiberaceae, Lamiaceae, Araceae, Convolvulaceae, Dioscoreaceae, and Nelumbaceae. Specific examples include leafy vegetables such as komatsuna, Chinese cabbage, onion, green onion, garlic, scallion, Chinese chives, lettuce, bok choy, cabbage, cauliflower, broccoli, Brussels sprouts, asparagus, lettuce, salad lettuce, celery, spinach, chrysanthemum, parsley, mitsuba, Japanese parsley, 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, burdocks, potatoes, taro, sweet potatoes, yams, ginger, and lotus roots; rice varieties (e.g., paddy rice, upland rice), wheat varieties (e.g., wheat, barley); and flowers. Examples of woody plants include the genus Cryptomeria japonica (e.g., Japanese cedar), the genus Chamaecyparis obtusifolia (e.g., Japanese cypress), the family Pinaceae (the genus Pinus (e.g., Japanese larch), the genus Larix (e.g., Japanese larch, Larch), the genus Abies (e.g., Abies sachalinensis)), the genus Eucalyptus (e.g., Eucalyptus), the genus Prunus (e.g., Cherry, Prunus mume, Prunus tomentosa), the genus Mangifera (e.g., Mango), the genus Acacia, the genus Myrica rubra, the genus Quercus acutissima (e.g., Quercus acutissima), the genus Vitis, the genus Malus, the genus Rosa, the genus Camellia (e.g., Tea), the genus Jacaranda (e.g., Jacaranda), the genus Crocodile (e.g., Avocado), the genus Pyrus (e.g., Pear), and the genus Sandalwood (e.g., Sandalwood (Sandalwood)). Among these, herbaceous plants are preferred, and plants of the family Brassicaceae and Fabaceae are more preferred.

[0061] Examples of plant growth promotion include increasing the amount of growth (increasing the growth rate), multiplication of the plant body (or parts of the plant body such as fruits or roots), promoting germination, promoting differentiation (for example, tissue culture such as cuttings and scion cuttings), increasing the content of inorganic elements (e.g., magnesium, phosphorus, potassium, calcium), and improving the quality such as improving the taste of the edible part. In the case of leafy vegetables, this can be confirmed by measuring the germination rate, SPAD value, root growth amount, head formation rate, head weight, outer leaf size, etc. In the case of fruit vegetables where the edible part is a seed (for example, soybean, edamame, broad bean), this can be confirmed by measuring the plant height, grain weight, thousand kernel weight, etc.

[0062] [1.4 Optional components] The plant growth promoter may contain components (optional components) other than the lignosulfonic acid component, as necessary. Examples of the optional components include optional components (formulation auxiliaries) such as plant growth promoting components other than the lignosulfonic acid component, excipients, colorants, preservatives, pH regulators, stabilizers, disintegrants, carriers, binders, pH adjusters, antifoaming agents, nonionic surfactants, cationic surfactants, and amphoteric surfactants.

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

[0064] Examples of inorganic components include essential elements such as nitrogen, phosphorus, and potassium, and trace elements such as sulfur, calcium, magnesium, iron, manganese, zinc, boron, molybdenum, chlorine, iodine, and cobalt, as well as inorganic salts, oxides, chlorides, sulfates, hydroxides, and carbonates thereof. Examples of inorganic components include magnesium hydroxide, magnesium oxide, calcium carbonate (slaked lime), potassium nitrate, ammonium nitrate, ammonium chloride, sodium nitrate, monoammonium phosphate, potassium monohydrogen phosphate, sodium dihydrogen phosphate, potassium oxide (salt salt), potassium chloride, potassium sulfate (sulfate), ammonium sulfate (ammonium sulfate), magnesium sulfate, calcium sulfate, ferrous sulfate, ferrous 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 (e.g., peroxycarbonate (a mixture of monocalcium phosphate and calcium sulfate), soluble phosphorus (a mixture of citric acid-soluble phosphoric acid, lime, magnesium (magnesium) and the like), potassium phosphate nitrate (a mixture of ammonium nitrate, potassium sulfate, monoammonium phosphate and the like)), and hydrates thereof.

[0065] Examples of antioxidants include ascorbic acid and sulfites, with ascorbic acid being preferred. Ascorbic acid has low residual capacity in the medium and can therefore prevent environmental pollution.

[0066] Examples of carbon sources include compounds such as carbohydrates and derivatives thereof, such as sucrose; organic acids, such as fatty acids; and primary alcohols, such as 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 of the optional components include inorganic components, organic materials (for example, compost, oil cake, humic acid, and other humic substances), and microbial materials (for example, yeast). The optional components may be used alone or in combination of two or more. The fertilizer component may be a fast-acting fertilizer, a slow-acting fertilizer, or a delayed-acting fertilizer, and may be any of an inorganic fertilizer, an organic fertilizer, and a chemical fertilizer.

[0069] The content of each optional component may be selected appropriately.

[0070] [1.5 Dosage form, manufacturing method] The plant growth promoter may be in any form, including, for example, powder, granule, grain, and liquid, and is not particularly limited. Granules and grains can facilitate spraying. Liquids can facilitate mixing with functional components, and can stabilize the slurry after mixing. The plant growth promoter may be formulated together with the functional components, or may be formulated separately. The method for producing the plant growth promoter can be appropriately selected according to the formulation.

[0071] [2. Plant Production Method] The above-mentioned plant growth promoter can be used in plant production. This can promote plant growth, leading to increased agricultural production. The target plants are the same as the above-mentioned examples of the target plants.

[0072] [Terms of use] The conditions for using the plant growth promoter are not particularly limited. For example, the plant growth promoter may be administered to a support and / or a plant body (e.g., leaves, stems) used in plant production. Examples of the support 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 husk; porous molded products such as foamed phenolic resin and rock wool; solidifying agents (e.g., agar or gellan gum), and combinations of two or more of these. The administration method may vary depending on the formulation and the type of support, but may include, for example, spraying and application (the agent may be mixed with water and sprayed during irrigation), and may further include mixing treatment such as stirring as necessary. The administration time of the plant growth promoter of the present invention is not particularly limited, and may be administered to a support before use, or may be added once or multiple times after the start of growth of the plant body from a seedling or seed, or may be both. The dosage of the plant growth promoter of the present invention may be appropriately determined depending on the plant species, the time of addition, the cultivation conditions, etc., but is usually 0.000001% by weight or more, preferably 0.00001% by weight or more, more preferably 0.00005% by weight or more, calculated as a lignin sulfonic acid component, per support (e.g., culture soil). The upper limit is not particularly limited, but is usually 10% by weight or less.

[0073] The plant growth promoter may be used in combination with other plant growth promoters. In the case of combined use, the plant growth promoter and other agents may be mixed and administered simultaneously, or each may be administered separately at an appropriate time. Examples of other agents include the above-mentioned fertilizers.

[0074] When producing plants using a plant growth promoter, the plant cultivation conditions (e.g., temperature, light intensity, type of light (e.g., artificial light, sunlight), light cycle, irrigation amount, humidity, carbon dioxide concentration, whether or not these are adjusted, sowing density, irrigation method, irrigation amount, whether or not 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 promoter may be used together with a plant seed or seedling to form a plant cultivation kit. The target plant may be any of the above-mentioned examples of the target plant. The seed or seedling may be selected depending on the plant species. The cultivation kit may further include a support and a container. The support and container may be any of the above-mentioned examples of the support and container. EXAMPLES

[0076] The present invention will now be described with reference to examples, which are not intended to limit the scope of the present invention.

[0077] The compositions of the main samples used in the examples are shown in Table 1.

[0078] [Table 1]

[0079] [Table 1 Footnotes] *1 "%" indicates the mass % relative to the dry weight of the sample.

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

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

[0082] *4 Reducing sugar content The content of reducing sugars in the lignin fertilizer was calculated by converting the values ​​measured by the Somogyi-Schaffer method into glucose content.

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

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

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

[0086] *8 Sulfur atom (S) content of sulfonic groups The S content of the sulfonic group was calculated according to the following formula. Sulfonic acid content of sulfonic acid groups (mass%) = S content (mass%) - inorganic S content (mass%) In the formula, the mass % is the ratio of the S content to the solid content of lignosulfonic acid. The S content is a value measured by the method described above. The inorganic S content is the sum of the SO3 content and the SO4 content determined by the method described above.

[0087] *9 Weight average molecular weight (RI) Measurement was performed by gel permeation chromatography (GPC) under the following conditions. Measuring device: Tosoh 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 material: Polyethylene glycol (Tosoh or GL Science) Detector: Differential refractometer (Tosoh Corporation) Calibration curve; Polyethylene glycol standard

[0088] *10 Weight average molecular weight (UV) The measurement was carried out under the same conditions as for the weight average molecular weight by RI detection described above, except that a UV detector (280 nm, manufactured by Tosoh Corporation) was used as the detector.

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

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

[0091] <Production Example 2: Production of Sample 2> The intermediate composition A obtained in Production Example 1 was subjected to 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), and the pH was adjusted to 7.0. This was spray-dried to obtain Sample 2, which is a solidified composition.

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

[0093] <Production Example 4: Production of Sample 4> A lignin-containing material (kraft lignin) was prepared from kraft cooking black liquor by a conventional method. 3 kg of conifer kraft cooking black liquor was placed in a beaker, kept at 60°C, and carbon dioxide was blown in under atmospheric pressure while stirring until the pH reached 10. After that, stirring was continued for 1 hour at 80°C to produce precipitate 3, which was then dehydrated by filtration to obtain a carbonate lignin cake. The obtained carbonate lignin cake was transferred to a beaker, and pure water was added so that the solid content concentration was 15% by mass, and the mixture was stirred to obtain a homogeneous slurry. While keeping the temperature at 50°C, 8N sulfuric acid was added while stirring until the pH of the above slurry became 2. Stirring was then continued at 50°C for 1 hour to produce precipitate 4. The above slurry was filtered through a Buchner funnel, and 100 ml of hot water at 50°C was added to the obtained lignin cake (precipitate 4), and filtration and washing were repeated until the electrical conductivity of the filtrate was 0.2 S / m or less, thereby obtaining a lignin-containing material. The obtained lignin-containing material was dried with a blower dryer at 50°C (solid content concentration: 95% by mass).

[0094] <Production Example 5: Production of Sample 5> A lignin-containing material (soda lignin) was prepared from soda cooking black liquor in a conventional manner. 200 ml of black liquor from soda AQ cooking of rice straw was placed in a beaker, kept at 70°C, and carbon dioxide was blown into it under atmospheric pressure while stirring until the pH reached 8. 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 carbonate lignin cake was transferred to a beaker, and pure water was added so that the solid content concentration was 15% by mass, and the mixture was stirred to obtain a homogeneous slurry. While keeping the temperature at 50°C, 8N sulfuric acid was added while stirring until the pH of the above slurry became 2. Stirring was then continued at 50°C for 1 hour to produce precipitate 2. The above slurry was filtered through a Buchner funnel, and 100 ml of hot water at 50°C was added to the obtained lignin cake (precipitate 2), and filtration and washing were repeated until the electrical conductivity of the filtrate was 0.5 S / m or less, thereby obtaining a lignin-containing material. The obtained lignin-containing material was dried with a blower dryer at 50°C (solid content concentration: 95% by mass).

[0095] <Test Example 1: Komatsuna Cultivation Test> (1) Cultivation by sunlight (Examples 1-2 and Comparative Examples 1-3) Komatsuna (Atariya Farm Komatsuna) was sown on August 23, 2021. The sowing interval was 250 seeds / m. 2 The number of seeds sowed per pot (size: 7L, dimensions 450mm x 208mm x 170mm) was 20. The culture soil was prepared by spreading each sample and other fertilizers shown in Table 2 on 5L of soil ("Flower / Vegetable Planter Soil, Planter Culture Soil" manufactured by Togawa Heiwa Farm: Akadama soil, vermiculite, bark compost) and mixing. The pots were placed indoors in a room with a skylight for cultivation. During the cultivation period, the skylight was left open to allow sunlight in. A screen was placed over the skylight to avoid direct sunlight. The temperature in the room was the same as the outdoor temperature. The frequency of watering was when the soil surface of the blank was dry (about once every 1-2 days). The amount of watering was such that the soil was sufficiently moistened, and the same amount of water was given each time, taking care not to let the water hit the leaves directly with the shower-like nozzle and cause them to fall over.

[0096] For each plot, four plants were selected from those that germinated on the 14th day after the start of cultivation. In addition, 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 a guide to the amount of chlorophyll for a leaf selected from the part close to the apex of each individual, and the average value was calculated (N = 10). In addition, on the 42nd day after the start of cultivation, the root development (the state in which the roots are spread vertically and horizontally underground) of each individual (N = 4) was visually observed, and the average plant body was used to evaluate according to the following criteria: ◎ Very good root development compared to the non-additive product, 〇 Good root development compared to the non-additive product, △ Equivalent root development compared to the non-additive product, × Poor root development compared to the non-additive product (Table 2). The yield was converted to that of the non-additive plot (Table 2).

[0097] (2) Cultivation under artificial light (Examples 3 to 6 and Comparative Examples 4 to 10) On February 25, 2022, the soil was prepared in the same manner as in test (1), except that the samples shown in Table 3 were used, and Komatsuna seeds were sown. The pots were placed on a windowsill indoors, the temperature was set to 20°C, and the light cycle was 9 hours light and 14 hours dark, and light was applied using a Fujikura plant growth clip lamp.

[0098] For each plot, the number of germinated seeds (per 20 seeds) was counted on the 14th day after the start of cultivation. In addition, on the 28th day after the start of cultivation, the SPAD value (Spoil Plant Analysis Development) was measured for 10 leaves selected from the part close to the stem apex of each individual as a guide to the amount of chlorophyll using a Konica Minolta chlorophyll meter, SPAD-502, and the average value was calculated (N=10). In addition, on the 28th day after the start of cultivation, the root development of each individual (N=4) was visually observed and evaluated according to the same criteria as in the test (1) (Table 3).

[0099] [Table 2]

[0100] [Table 3]

[0101] [Notes to Tables 2 and 3] *1 The amount of phosphorus, nitrogen, and potassium is the weight percentage of the sample added to the culture soil. *2 In Comparative Examples 2 and 5, Hachipara Ace (slow release fertilizer, P10, N10, K10, magnesium 1), manufactured by Toyochu, was used as a commercially available fertilizer. *3 In Comparative Examples 3, 9 and 10 and Examples 2 and 6, yeast (Cavitrula, manufactured by Nippon Paper Industries Co., Ltd.) was used. *4 In Examples 2 and 6, the weight ratio of yeast to sample 1 was 9.78:10 in order to match the amount of nitrogen in commercially available fertilizers. *5 In Comparative Example 10, the yeast:lignin (weight ratio) was set to 9.78:10 in order to match the amounts added in Example 6.

[0102] In both the cultivation tests using sunlight and artificial light, the roots of the Examples were better than those of the Comparative Examples. In addition, each of the Examples showed a high SPAD value (Tables 2 and 3).

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

[0104] Each plot was harvested on November 20th of the same year, and the yield, amount of MgO contained in the Chinese cabbage, head weight, outer leaves, and head formation rate were measured, and an index was calculated for each measurement value, with the value for no sample added (Comparative Example 11) set at 100 (Table 5).

[0105] [Table 4]

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

[0107] [Table 5]

[0108] [Footnotes to Table 5] *1 Head weight (g) is the average weight of headed Chinese cabbage. *2 MgO (unit: mg) is the MgO content (%) contained in Chinese cabbage, and was measured using the following method. 10-20 stalks of average size were selected from the field and collected. For medium to large sized ones, 8-10 pieces were divided vertically into 4-8 pieces, and one section was taken from each. For small ones, about 20 pieces were collected. The leaves were then peeled off and the pieces were spread out and dried through ventilation. If necessary, the pieces were separated into inner and outer leaves. After drying, the pieces were pulverized using a Willey-type or coffee mill-type grinder to obtain a powder sample, which was measured in the same manner as the MgO measurement method described above. *3 Outer leaves (cm) are the maximum leaf length of the outer leaves (N=3). *4 Head formation rate (%) is the ratio of head-forming individuals to the total number of individuals.

[0109] Examples 7 to 9 had a higher MgO content and larger outer leaves than the comparative example. Among them, Examples 7 and 9 had good yields and head weights, and Example 7 also had a high head formation rate (Table 5).

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

[0111] [Table 6]

[0112] [Notes 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 (Sun & Hope Co., ammonium sulfate, superphosphate, and potassium sulfate; N: ammonium sulfate 21%, P2O5: superphosphate 16.5%, and K2O: sulfate 50%) added to each plot and the samples used in each plot. *2 MgO is the amount of MgO contained in each sample, and was measured in the same manner as in Test Example 2.

[0113] [Table 7]

[0114] [Footnotes for Table 7] *1 Plant height (cm) is the height from ground surface to the top (N=4). *2 Grain weight (g / m 2= kg / 10a) is the weight of grain (N=1) per plot (10a). *3 Thousand kernel weight (unit: g) is the average weight of 1,000 kernels (N=1).

[0115] The embodiment had a larger grain weight or grass bamboo than the non-added (control) comparative example 16. Among them, the embodiment 10 also showed a high thousand-grain weight.

[0116] <Test Example 4: Calcium carbonate dispersion test (B-type viscosity test) (Example 14, Comparative Examples 21 to 24)> The effect of calcium carbonate, which is used as an extender in pesticides, on the dispersibility was evaluated. 172.44 g of calcium carbonate (water content 30%) was mixed with 37.56 g of water and each dispersant shown in Table 8 and stirred to prepare a slurry. 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 amount of the slurry. Stirring was performed with a Homo Disper 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.) at 20°C, 60 rpm, No. 3 rotor or No. 2 rotor, without guard (Table 8).

[0117] [Table 8]

[0118] Example 14, which used sample 3, had a lower viscosity than Comparative Examples 21 to 24, which used water only or samples 4 to 6, demonstrating that the plant growth promoter of the present invention exhibits good dispersibility, is retained in the culture medium, and can enhance the dispersibility of fertilizer components and pesticide components.

[0119] <Test Example 5: Fertilizer Efficacy Test Using Sample 1 (Examples 15 to 25, Comparative Examples 25 to 27)> (1) Onion On September 16, yellow onions (Kaizuka-wase) were sown in the seedbed, and on November 18 of the same year, the heads were planted in soil (red-yellow soil derived from beach deposits, 13.1 m per plot). 2 The planting conditions were 75cm bank width, 2 rows, 12cm spacing, and a planting density of 2222 plants / a. As common fertilizers, Kumiai Kasei No. 11 (N, P2O5, K2O) 2kg / a, F·T·E (B9%, Mn19%) 0.4kg / a, and humic acid PVA were used, and the fertilizers listed in Table 9 were added to each plot. The plants were harvested on June 3 of the following year, and the yield was measured (Table 10).

[0120] [Table 9]

[0121] [Table 10]

[0122] [Footnotes for Table 10] Table 10 shows the 1.8m area with few missing stumps. 2 The results of a yield survey were presented.

[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), and then the lignin sample (sample 1) was placed on top of it in the amounts shown in Table 11, and soil was placed again in the upper layer (up to 10 cm from the pot opening) to prepare 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 of it in the amounts shown in Table 11 (up to the pot opening) to prepare pots for the surface layer treatment. In addition, 2.0 g of N (ammonium sulfate), 1.0 g of P2O2 (peroxide or dissolved phosphorus) and 1.0 g of K2O (salted) were applied to each treatment as common feed. For each treatment plot, wheat (Norin wheat No. 50) was sown in three pots (four seeds per pot) on November 14th. Then, on December 15th of the same year, the plants were thinned out to leave three seeds per pot, and then harvested on June 15th of the following year after the plants had matured (Table 11).

[0124] [Table 11]

[0125] [Notes for Table 11] Table 11 shows the average value (air-dried matter amount per pot) for triplicates per plot.

[0126] <Test Example 6: Fertilizer Efficacy Test Using Sample 2 (Examples 26 to 45, Comparative Examples 28 to 43)> (1) Cucumbers and eggplants On May 9, cucumber seedlings (four-leaf cucumber, four true leaves, plant height 8 cm) and eggplant seedlings (first generation hybrid high-quality early-ripening medium-quality eggplant, five true leaves, plant height 18 cm) were transplanted into soil (diluvial sandy loam) (1st area 3.3 m 2 The fertilizers were humic acid PVA as a common fertilizer, and the fertilizers shown in Table 12 were added to each plot. Growth surveys and yield measurements were conducted over time (Tables 13 and 14: N=3).

[0127] [Table 12]

[0128] [Table 13]

[0129] [Table 14]

[0130] [Notes to Tables 13 and 14] The growth volume is the average growth volume (cm) per plant in each plot. The numbers in parentheses for growth indicate the number of leaves for cucumbers and the number of branches for eggplants. The yield is the total weight (g) of three plants in each plot. The numbers in parentheses for yield indicate the number of individuals.

[0131] (2) Melon Melons (Earl's variety, Nan'en No. 2) were divided into three sections (Table 15) and grown in a vinyl greenhouse with each section measuring 1 m 2 The cultivation test was carried out in one series. Seeds were sown in soil (diluvial layered loam) on June 8, temporary planted on June 15, and planted (four true leaves) on July 2. Then, top pinching (July 18), crossing (July 21-26), fruit thinning (July 29), hanging (July 30), bagging (August 7) ​​were carried out in sequence, and the plants were harvested on September 4. Fertilization was carried out for each section with the fertilizers shown in Table 15 and common fertilizers (humic acid, PVA-based), the first time (basal fertilizer), the second time (first top dressing) was done immediately after fruit thinning on July 2, and the third time (second top dressing) was done when the net started to emerge. Irrigation was carried out twice before crossing and three times after crossing. Dithane and charathane were sprayed seven times as fungicides and disinfectants. Temperature and humidity were controlled as follows: seedling stage 30°C daytime, 22°C nighttime; vegetative stage 32°C daytime, 25°C nighttime, 75% humidity; fruiting stage 32°C daytime, 24°C nighttime, 94% humidity; harvest stage windows were opened to reduce humidity. Yields were measured and fruits were evaluated (Tables 16 and 17).

[0132] [Table 15]

[0133] [Table 16]

[0134] [Table 17]

[0135] (3) Corn Soil (either of the following: Kofu Basin filled alluvial soil topsoil or Yatsugatake brown volcanic ash soil subsoil) 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 the crop was harvested on August 12th.

[0136] [Table 18]

[0137] [Notes to Table 18] The three elements, CaCO3, lignin (sample 2), and compost were mixed into the entire soil layer from 0 to 10 cm. The fertilizers applied were as follows: ammonium sulfate 21%, peroxycarbonate 19.5%, sulfuric acid 50%; compost components N 0.59%, P2O 50.23%, K2O 0.66% excluded; lignin magnesium MgO 5.0%

[0138] [Table 19]

[0139] [Table 20]

[0140] (4) Turnip Soil to which lignin (sample 2) had been added (either of the following: topsoil of the Kofu Basin alluvial land field soil or subsoil of the Yatsugatake brown volcanic ash soil) was placed in a 1 / 2000a Wagner pot, and small turnips (Someya Kanamachi) were sown on April 30th and fertilized (Table 21). Disinfection and other procedures were carried out on May 20th and 30th, and weeding was carried out on June 7th. Growth was monitored over time during the cultivation period (Table 22), and the plant was harvested on June 11th, after which the yield was monitored (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 soil (alluvial layer field soil) with a planting density adjusted to two rows with 30 grains per row. It was sown and fertilized on May 13th (Table 24), harvested on November 4th of the same year, and its growth was investigated (Table 25).

[0145] [Table 24]

[0146] [Footnotes to Table 24] Chemical fertilizer: N 1.0kg / 10a, P2O5 1.0kg / 10a, K2O 0.8kg / 10a (Kumiai phosphorus nitrate potassium: N 15.0%, P 15.0%, K 12.0%) Lignin Magnesium Oxide MgO5.0%

[0147] [Table 25]

[0148] (6) Summer carrots The soil was plowed to a depth of 15 cm, and the common fertilizer and the fertilizers shown in Table 26 were applied to the fertilizer furrows. The ridges were 60 cm wide (13.1 m per section). 2 On June 11th, carrots (Kuroda Gosun Ninjin) were sown (two rows). The plants were thinned to 15cm apart, giving a total of approximately 2220 plants / a. When the soil had dried to the point where the soil moisture tension at a depth of 10cm within the rows exceeded pF2.5, irrigation was carried out at 20-30mm intervals, for a total of 180mm. The plant was harvested on September 16th, and the yield, component content, and nutrient absorption of the harvested product were measured (Tables 27 and 28).

[0149] [Table 26]

[0150] [Table 27]

[0151] [Table 28]

[0152] (7) Autumn carrots The common fertilizer and the fertilizers shown in Table 29 were applied to the soil (fine-grained soil with little humus derived from unconsolidated Pleistocene deposits) (August 2nd). Ridges were made with a width of 60 cm (9 m per section). 2 (3m x 3m, 3 rows), and on September 1st, carrots (Kuroda Gosun Ninjin) were sown (two rows). The plants were thinned out to 15cm apart, giving a total of approximately 2220 plants / a. When the soil moisture tension at a depth of 10cm within the rows had dried to a level exceeding pF2.5, irrigation was carried out at 10-20mm intervals, totalling 220mm. The plants were harvested on January 6th of the following year, and growth was investigated and nutrient absorption was measured (Table 30).

[0153] [Table 29]

[0154] [Table 30]

[0155] <Test Example 7: Fertilizer Efficacy Test Using Calcium Lignosulfonate (Examples 46 to 49, Comparative Examples 44 to 47)> (1) Onion Yellow onions (Senshu yellow onions) were sown in a bed on September 6th, and the heads were planted in soil (Kofu Basin reclaimed alluvial soil, loam) on November 10th. Planting conditions were 100cm width on the bank, 4 rows planted, 18cm spacing between plants, and 12cm spacing between plants. Fertilizers shown in Tables 31 and 32 (also treated with nitrohumic acid PVA, etc.) were applied as basal fertilizer on November 6th, and top dressing on February 23rd, March 28th, and April 16th of the following year. They were harvested 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 26, rice (Pi5) seedlings were planted in paddy fields (paddy soil: granite sandy loam, 10 m per plot). 2 Three plants were planted in a 3m x 3.35m square grid (planting density: 1m 2 The number of plants per year was 32 (25cm x 12.5cm). The fertilizers shown in Table 34 were applied at each stage. The heading occurred on September 2nd, and then pesticides such as Diazinon, PCP, and Fumiron were sprayed. The plants were harvested on October 31st, and growth was investigated and phosphorus and potassium contents were measured (Tables 35 and 36).

[0160]

Table 34

[0161]

Table 35

[0162]

Table 36

Claims

1. A plant growth promoter comprising a lignin sulfonic acid component in which the ratio of the sulfur atom content derived from sulfonic groups to the sulfur atom content contained in the lignin sulfonic acid is 0.5 or more, the calcium atom content is 0.001% by weight or more, the sodium atom content is 0.3% by weight or more, and the magnesium atom content is 0.05% by weight or more.

2. For the lignin sulfonic acid component, the reducing sugar content is 30% by weight or less, the sulfur atom content derived from sulfonic groups is 3.0% by weight or more, and the phenolic hydroxyl group content is 0.5% by weight or more, The agent according to claim 1, which satisfies at least any one of the above.

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 a substituent derived from (poly)alkylene oxide.

6. A method for producing a plant, comprising cultivating the plant using the agent according to claim 1 or 2.

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