Concentrated composition for soil improvement

Abstract

Disclosed is a concentrated composition for soil improvement, which contains (A) carboxymethyl cellulose and / or a salt thereof (hereinafter referred to as component (A)), (B) one or more inorganic salts that are selected from among sulfates, phosphates, nitrates, carbonates, and chloride salts (hereinafter referred to as component (B)), and water, wherein the content of component (A) is 2 to 15% by mass inclusive and the mass ratio ((A) / (B)) of the content of component (A) to the content of component (B) is 0.11 to 0.4 inclusive in the composition.

Description

Concentrated soil improvement composition

[0001] The present invention relates to a concentrated soil improving composition, a method for producing a concentrated soil improving composition, and a method for improving soil.

[0002] BACKGROUND ART In fields where agricultural crops are grown, soil properties are an important factor in terms of improving productivity, etc. In particular, poor drainage in fields is known to cause reduced crop yields due to water damage (Journal of the Crop Science Society of Japan, Crop Science Society of Japan, 2011, Vol. 80, No. 1, pp. 65-72). To improve permeability, various forms of soil conditioners have been proposed. Soil conditioners include solid and liquid agents.

[0003] As a solid formulation, Japanese Patent Publication No. 2004-236530 discloses a culture soil containing 0.0001 to 0.5 parts by weight of a water-soluble cellulose derivative per 100 parts by weight of soil. On the other hand, as a liquid formulation, Japanese Patent Publication No. 2018-170998 discloses an agricultural liquid mulch composition containing (A) component: carboxymethylcellulose or a salt thereof, (B) component: a cationic polymer, and (D) component: a colorant. Japanese Patent Publication No. 2017-109999 discloses a pesticide efficacy enhancer composition containing (A) a specific cellulose derivative A, (B) one or more compounds selected from sulfates, phosphates, nitrates, sucrose, glucose, fructose, sorbitol, and glycerin, and (C) a specific surfactant and water. Furthermore, Japanese Patent Publication No. 2-227433 discloses a method for producing an aqueous suspension of carboxymethylcellulose salt. Japanese Patent Laid-Open Publication No. 2-227433 discloses a method for producing an aqueous suspension of a water-soluble carboxymethyl cellulose salt, which includes: (a) a step of dissolving at least 33% by weight of potassium carbonate in water; and (b) a step of dispersing at least 8% by weight of a carboxymethyl cellulose salt, based on the total weight of the resulting aqueous suspension, therein while stirring.

[0004] Summary of the Invention When cultivating crops in fields, etc., it is necessary to maintain soil suitable for cultivation, for example, soil with appropriate water permeability. Specifically, by forming soil into an aggregated structure, the air-phase ratio of the soil is increased, which is expected to improve soil drainage and rhizosphere growth. However, an easy-to-use and economically reasonable soil conditioner has not been obtained. The present inventors focused on liquid agents and completed the present invention as a result of extensive research. The present invention provides a concentrated solution for a soil improvement composition with excellent soil improvement performance, which has easy-to-handle fluidity, storage stability, and rapid water solubility upon dilution; a method for producing the concentrated soil improvement composition; and a soil improvement method in which the concentrated composition is diluted and used.

[0005] The present invention relates to a concentrated soil improvement composition comprising (A) carboxymethylcellulose and / or a salt thereof (hereinafter referred to as component (A)), (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides (hereinafter referred to as component (B)), and water, wherein the content of component (A) in the composition is 2% by mass or more and 15% by mass or less, and the mass ratio of the content of component (A) to the content of component (B) [(A) / (B)] is 0.11 or more and 0.4 or less.

[0006] The present invention also relates to a method for producing a concentrated soil improvement composition, which includes the steps of mixing (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides with water, and then mixing the resulting mixture (I) with (A) carboxymethyl cellulose and / or a salt thereof to produce mixture (II).

[0007] The present invention also relates to a method for improving soil, which comprises diluting the concentrated soil improving composition with water to prepare a soil improving composition, and applying the resulting composition to soil.

[0008] According to the present invention, there are provided a concentrated solution for a soil improvement composition that has excellent soil improvement performance, has easy-to-handle fluidity, storage stability, and rapid water solubility when diluted, a method for producing the concentrated soil improvement composition, and a soil improvement method in which the concentrated composition is diluted and used.

[0009] 1 is a photograph showing the state of concentrated soil improving compositions of Examples and Comparative Examples.

[0010] Modes for Carrying Out the Invention The reasons why the soil improvement concentrated composition of the present invention has easy-to-handle fluidity, storage stability, and rapid water solubility upon dilution, and why soil improvement compositions obtained by diluting the concentrated composition have excellent soil improvement properties, are unclear, but are presumed to be as follows. The combined use of component (A) carboxymethylcellulose and / or its salt with a predetermined concentration of component (B) inorganic salt prevents component (A) from dissolving in water due to a salting-out effect, thereby improving the fluidity, storage stability, and water solubility upon dilution of the composition containing component (A). Furthermore, by diluting a soil improvement concentrated composition in which component (A) is well dispersed with water and spraying it on soil in a field or the like, the soil is efficiently covered, thereby significantly improving the drainage (also known as permeability) of the soil compared to spraying the same amount of solid component (A). This effect is significant and unexpected to those skilled in the art. The soil improvement concentrated composition, the method for producing the soil improvement concentrated composition, and the soil improvement method of the present invention are not limited to the above-mentioned mechanism of action.

[0011] <Concentrated soil improvement composition> The concentrated soil improvement composition of the present invention contains (A) carboxymethyl cellulose and / or a salt thereof [hereinafter referred to as component (A)], (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides [hereinafter referred to as component (B)], and water, wherein the content of component (A) in the composition is 2% by mass or more and 15% by mass or less, and the mass ratio of the content of component (A) to the content of component (B) [(A) / (B)] is 0.11 or more and 0.4 or less.

[0012] The soil improvement concentrate composition of the present invention may be a liquid soil improvement concentrate composition. In the present invention, soil improvement refers to improving the drainage of soil. By improving the drainage of soil, one or more effects selected from promoting the formation of soil aggregates, increasing the air-phase ratio of soil, and reducing soil hardness can be expected.

[0013] <Component (A)> Component (A) is carboxymethyl cellulose and / or a salt thereof. Examples of counter ions of the carboxymethyl group of component (A) include hydrogen ions and alkali metal ions such as sodium ions.

[0014] The degree of substitution per structural unit of the carboxymethyl group of component (A) is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 0.6 or more, even more preferably 0.7 or more, and even more preferably 0.8 or more, from the viewpoint of improving the storage stability of the soil improvement concentrated composition and the drainage of the soil improvement composition. From the viewpoint of improving economic rationality, it is preferably 2.5 or less, more preferably 2.0 or less, even more preferably 1.8 or less, and even more preferably 1.5 or less. Taking these viewpoints into consideration, the degree of substitution per structural unit of the carboxymethyl group of component (A) is preferably 0.1 or more and 2.5 or less, more preferably 0.5 or more and 2.0 or less, even more preferably 0.6 or more and 1.8 or less, and even more preferably 0.8 or more and 1.5 or less. The degree of substitution per structural unit of the carboxymethyl group of component (A) can be measured by the method described in the Examples.

[0015] The viscosity of a 1% by mass aqueous solution of component (A) at 25°C is preferably 100 mPa·s or more, more preferably 500 mPa·s or more, even more preferably 1,000 mPa·s or more, and still more preferably 2,000 mPa·s or more, from the viewpoint of improving the storage stability of the concentrated soil improvement composition and the drainage properties of the soil improvement composition, and is preferably 30,000 mPa·s or less, more preferably 15,000 mPa·s or less, even more preferably 10,000 mPa·s or less, even more preferably 5,000 mPa·s or less, even more preferably 3,500 mPa·s or less, and still more preferably 2,800 mPa·s or less, from the viewpoint of improving handleability when diluted. Taking all these points into consideration, the viscosity of a 1% by mass aqueous solution of component (A) at 25°C is preferably from 100 to 30,000 mPa·s, more preferably from 500 to 15,000 mPa·s, even more preferably from 1,000 to 10,000 mPa·s, still more preferably from 2,000 to 5,000 mPa·s, even more preferably from 2,000 to 3,500 mPa·s, and even more preferably from 2,000 to 2,800 mPa·s. In the present invention, the viscosity of component (A) is measured according to the method shown below.

[0016] Method for Measuring Viscosity (mPa s) of a 1% by Mass Aqueous Solution of Component (A) In the present invention, the viscosity (mPa s) of a 1% by mass aqueous solution of component (A) at 25°C is measured using a Brookfield viscometer (for example, TVB-10, manufactured by Toki Sangyo Co., Ltd.). When the viscosity of the aqueous solution is less than 50 mPa s, the measurement is performed using a rotor M1 at a rotation speed of 30 rpm for a measurement time of 60 seconds; when the viscosity of the aqueous solution is 50 mPa s or more but less than 1,000 mPa s, the measurement is performed using a rotor M2 at a rotation speed of 30 rpm for a measurement time of 60 seconds; and when the viscosity of the aqueous solution is 1,000 mPa s or more but less than 5,000 mPa s, the measurement is performed using a rotor M3 at a rotation speed of 30 rpm for a measurement time of 60 seconds. When the viscosity of the aqueous solution is 5,000 mPa·s or more and 40,000 mPa·s or less, the viscosity is measured using a helical stand (manufactured by Toki Sangyo Co., Ltd.) with a spindle TC at a rotation speed of 0.5 rpm for a measurement time of 60 seconds.

[0017] Specific examples of the component (A) include the Sunrose series manufactured by Nippon Paper Industries Co., Ltd. (e.g., Sunrose F350HC, Sunrose F600MC, etc.) and the CMC Daicel series manufactured by Daicel Miraize Co., Ltd. (e.g., CMC Daicel 1390, etc.).

[0018] <Component (B)> Component (B) is one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides. Examples of salts of component (B) include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as magnesium salts, and ammonium salts. Preferably, the salt is at least one selected from alkali metal salts and ammonium salts, more preferably at least one selected from sodium salts, potassium salts, and ammonium salts. Specific examples of sulfates include alkali metal sulfates such as sodium sulfate and potassium sulfate, alkaline earth metal sulfates such as magnesium sulfate, and ammonium sulfate. Examples of phosphates include alkali metal phosphates such as disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate, and ammonium phosphates such as diammonium hydrogen phosphate and ammonium dihydrogen phosphate. Examples of nitrates include alkali metal nitrates such as sodium nitrate and potassium nitrate, alkaline earth metal nitrates such as magnesium nitrate, and ammonium nitrate. Examples of carbonates include alkali metal carbonates such as sodium carbonate and potassium carbonate, alkaline earth metal carbonates such as magnesium carbonate, and ammonium carbonate. Examples of chloride salts include alkali metal chlorides such as sodium chloride and potassium chloride, alkaline earth metal chlorides such as magnesium chloride, and ammonium chloride.

[0019] The component (B) is preferably one or more inorganic salts selected from sulfates, phosphates, and carbonates, more preferably one or more inorganic salts selected from ammonium sulfate, potassium carbonate, sodium carbonate, and diammonium hydrogen phosphate, and even more preferably ammonium sulfate.

[0020] <Water> Examples of water include deionized water, tap water, and distilled water. Water is used in an amount such that the composition of the soil improvement concentrate composition is 100% by mass, as the remainder other than component (A), component (B), and the optional components described below. The soil improvement concentrate composition of the present invention contains water in an amount of preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, even more preferably 60% by mass or more, and even more preferably 63% by mass or more, from the viewpoint of improving storage stability, and preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 68% by mass or less, from the viewpoint of improving fluidity.

[0021] <Composition, etc.> In the concentrated soil improvement composition of the present invention, the content of component (A) is 2% by mass or more, preferably 2.5% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and even more preferably 4.5% by mass or more, from the viewpoint of improving economic rationality and ease of handling, and is 15% by mass or less, preferably 11% by mass or less, more preferably 10% by mass or less, even more preferably 8% by mass or less, and even more preferably 7.5% by mass or less, from the viewpoint of improving fluidity.

[0022] In the concentrated soil improvement composition of the present invention, the content of component (B) is preferably 11% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, and even more preferably 27% by mass or more, from the viewpoint of improving fluidity, and is preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, and even more preferably 32% by mass or less, from the viewpoint of improving storage stability.

[0023] In the concentrated soil improvement composition of the present invention, the mass ratio of the content of component (A) to the content of component (B) in the composition [(A) / (B)] is 0.11 or more, preferably 0.12 or more, more preferably 0.15 or more, and even more preferably 0.17 or more, from the viewpoint of reducing viscosity, and is 0.4 or less, preferably 0.35 or less, more preferably 0.3 or less, even more preferably 0.25 or less, even more preferably 0.2 or less, and even more preferably 0.19 or less, from the viewpoint of improving storage stability.

[0024] <Component (C)> The soil improving concentrated composition of the present invention may further contain a polyether compound (C) (hereinafter referred to as component (C)). The soil improving concentrated composition of the present invention contains one or more types of component (C).

[0025] The component (C) is preferably one or more polyether compounds (c1) selected from compounds represented by the following general formula (c1), polyoxyalkylene alkyl ethers (c2), polyoxyalkylene sorbitan fatty acid esters (c3), polyoxyalkylene sorbitol fatty acid esters (c4), and polyoxyalkylene fatty acid esters (c5).

[0026] R １ｃ O-(AO) ｎ -R ２ｃ (c1) [wherein, R １ｃ and R ２ｃ are each independently a hydrogen atom or an alkyl or alkenyl group having from 1 to 6 carbon atoms, AO is an alkyleneoxy group having from 2 to 4 carbon atoms, and n is the average number of moles of AO added, which is from 2 to 1,800.

[0027] In general formula (c1), R １ｃ and R ２ｃ The number of carbon atoms in the alkyl group or alkenyl group in R is independently 1 or more, preferably 2 or more, from the viewpoint of improving fluidity and storage stability, and is 6 or less, preferably 4 or less, more preferably 3 or less, from the viewpoint of improving water solubility. １ｃ and R ２ｃThe alkyl or alkenyl groups in R are each independently a straight chain or a branched chain, and are preferably straight chain. １ｃ and R ２ｃ are each independently a hydrogen atom, an alkyl group, or an alkenyl group, and are preferably a hydrogen atom.

[0028] In general formula (c1), AO is preferably one or more alkyleneoxy groups selected from an ethyleneoxy group, a propyleneoxy group, and a butyleneoxy group, and more preferably an ethyleneoxy group, from the viewpoint of improving fluidity and storage stability. When AO contains different alkyleneoxy groups, the different alkyleneoxy groups may be bonded in a block bond or a random bond.

[0029] In general formula (c1), n ​​is 2 or more, preferably 5 or more, more preferably 10 or more, from the viewpoint of improving fluidity and storage stability, and is 1800 or less, preferably 500 or less, more preferably 200 or less, even more preferably 100 or less, and still more preferably 50 or less, from the viewpoint of improving fluidity and storage stability.

[0030] From the viewpoint of improving fluidity and storage stability, the polyoxyalkylene alkyl ether (c2) is a polyoxyalkylene alkyl ether in which the number of carbon atoms in the alkyl group is preferably 10 or more, more preferably 12 or more, even more preferably 14 or more, still more preferably 16 or more, and preferably 22 or less, more preferably 20 or less, and the average number of moles of oxyalkylene groups added is preferably 10 or more, more preferably 15 or more, even more preferably 20 or more, and preferably 50 or less, more preferably 40 or less, and even more preferably 35 or less. The oxyalkylene group is preferably an oxyethylene group. The polyoxyalkylene alkyl ether (c2) is more preferably polyoxyethylene oleyl ether.

[0031] From the viewpoint of improving fluidity and storage stability, the polyoxyalkylene sorbitan fatty acid ester (c3) is a polyoxyalkylene sorbitan fatty acid ester in which the number of carbon atoms in the fatty acid is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 20 or less, more preferably 18 or less, and even more preferably 14 or less, and the average number of moles of oxyalkylene groups added is preferably 10 or more, more preferably 15 or more, even more preferably 18 or more, and preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, and even more preferably 25 or less. The oxyalkylene group is preferably an oxyethylene group.

[0032] From the viewpoint of improving fluidity and storage stability, the polyoxyalkylene sorbitol fatty acid ester (c4) is a polyoxyalkylene sorbitol fatty acid ester in which the number of carbon atoms in the fatty acid is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 20 or less, more preferably 18 or less, and even more preferably 14 or less, and the average number of moles of oxyalkylene groups added is preferably 10 or more, more preferably 15 or more, even more preferably 18 or more, and preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, and even more preferably 25 or less. The oxyalkylene group is preferably an oxyethylene group.

[0033] From the viewpoint of improving fluidity and storage stability, the polyoxyalkylene fatty acid ester (c5) is a polyoxyalkylene fatty acid ester in which the number of carbon atoms in the fatty acid is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 20 or less, more preferably 18 or less, and even more preferably 14 or less, and the average number of moles of oxyalkylene groups added is preferably 10 or more, more preferably 15 or more, even more preferably 18 or more, and preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, and even more preferably 25 or less. The oxyalkylene group is preferably an oxyethylene group.

[0034] From the viewpoint of improving fluidity and storage stability, the component (C) is preferably the polyether compound (c1), and among these, one or more selected from polyalkylene glycol, polyalkylene glycol alkyl ether, and polyalkylene glycol dialkyl ether are preferred, one or more selected from polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polypropylene glycol, polypropylene glycol monomethyl ether, polypropylene glycol dimethyl ether, polytetramethylene oxide, and copolymers thereof are more preferred, one or more selected from polyethylene glycol and polyethylene glycol dimethyl ether are even more preferred, and polyethylene glycol is even more preferred. That is, from the viewpoint of improving fluidity and storage stability, the component (C) is preferably a polyether compound (c1) represented by the general formula (c1), where R １ｃ and R ２ｃ are each independently a hydrogen atom or a methyl group, preferably a hydrogen atom; AO is an oxyalkylene group having from 2 to 4 carbon atoms, preferably an oxyethylene group; and n is a number from 2 to 1,800.

[0035] From the viewpoint of improving fluidity and storage stability, the weight average molecular weight of component (C) is preferably 100 or more, more preferably 200 or more, even more preferably 240 or more, and even more preferably 300 or more. From the viewpoint of improving fluidity, it is preferably 50,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, even more preferably 2,000 or less, even more preferably 1,500 or less, even more preferably 1,000 or less, even more preferably 800 or less, and even more preferably 600 or less. The weight average molecular weight of component (C) is measured by gel permeation chromatography (GPC) using high performance liquid chromatography. The GPC measurement conditions are shown below.

[0036] *GPC conditions Apparatus: GPC (HLC-8320GPC) manufactured by Tosoh Corporation Column: G4000PWXL + G2500PWXL (manufactured by Tosoh Corporation) Eluent: chloroform (containing 1 mmol / L dimethyldodecylamine; Farmin DM20, manufactured by Kao Corporation) Flow rate: 1.0 mL / min Column temperature: 40°C Detection: RI Sample size: 0.2 mg / mL Standard substance: the following monodisperse polyethylene glycol PEO standard substance: molecular weights 786,000, 143,000, 37,600 (manufactured by Tosoh Corporation) PEG standard substance: molecular weights 7,000, 1,500, 400 (manufactured by GL Sciences Inc.)

[0037] When the soil improvement concentrate composition of the present invention contains component (C), the content of component (C) in the soil improvement concentrate composition of the present invention is, from the viewpoint of improving fluidity and storage stability, preferably 0.1 mass% or more, more preferably 0.25 mass% or more, even more preferably 0.5 mass% or more, even more preferably 1 mass% or more, even more preferably 1.5 mass% or more, even more preferably 2 mass% or more, and even more preferably 3 mass% or more, and from the viewpoint of improving fluidity and economic rationality, preferably 15 mass% or less, more preferably 10 mass% or less, even more preferably 8 mass% or less, even more preferably 5 mass% or less, and even more preferably 4 mass% or less.

[0038] When the soil improvement concentrated composition of the present invention contains component (C), the mass ratio of the content of component (C) to the content of component (A) in the composition [(C) / (A)] is preferably 0.05 or more, more preferably 0.1 or more, even more preferably 0.2 or more, and even more preferably 0.5 or more, from the viewpoint of improving fluidity and storage stability, and is preferably 3 or less, more preferably 2 or less, even more preferably 1.5 or less, and even more preferably 1.0 or less, from the viewpoint of improving fluidity and storage stability.

[0039] When the soil improvement concentrated composition of the present invention contains component (C), the mass ratio of the content of component (C) to the content of component (B) in the composition [(C) / (B)] is preferably 0.001 or more, more preferably 0.01 or more, even more preferably 0.02 or more, even more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoint of improving fluidity and storage stability, and is preferably 0.7 or less, more preferably 0.5 or less, even more preferably 0.35 or less, even more preferably 0.3 or less, and even more preferably 0.25 or less, from the viewpoint of improving fluidity and storage stability.

[0040] <Component (D)> The soil improvement concentrated composition of the present invention can optionally contain (D) a hydroxy acid or a salt thereof (hereinafter referred to as component (D)). Component (D) is a preferred component from the viewpoint of improving fluidity and storage stability. The soil improvement concentrated composition of the present invention contains one or more types of component (D). Examples of component (D) include malic acid, citric acid, isocitric acid, isopropyl citrate, hydroxymalonic acid, tartaric acid, 3-hydroxy-3-methylglutaric acid, mucic acid, gluconic acid, gallic acid, mevalonic acid, pantoic acid, orsellinic acid, gentisic acid, quinic acid, and salts thereof. Examples of salts of component (D) include sodium salts, potassium salts, calcium salts, and ammonium salts. Component (D) is preferably a polycarboxylic acid having a hydroxy group or a salt thereof, more preferably citric acid, malic acid, or a salt thereof, and even more preferably citric acid or a salt thereof. The polycarboxylic acid having a hydroxy group may have 1 to 4 hydroxy groups. The number of carbon atoms in the polycarboxylic acid having a hydroxy group may be, for example, 3 to 10. Furthermore, component (D), for example, the polycarboxylic acid having a hydroxy group or a salt thereof, may be a hydrate.

[0041] When the soil improvement concentrated composition of the present invention contains component (D), the soil improvement concentrated composition of the present invention contains component (D) in an amount of preferably 0.001 mass% or more, more preferably 0.003 mass% or more, even more preferably 0.01 mass% or more, even more preferably 0.03 mass% or more, and even more preferably 0.05 mass% or more, from the viewpoint of improving fluidity and storage stability, and preferably 5 mass% or less, more preferably 1 mass% or less, and even more preferably 0.5 mass% or less, from the viewpoint of improving fluidity and storage stability.

[0042] The viscosity of the soil improvement concentrated composition of the present invention at 25°C is preferably 1 mPa·s or more, more preferably 2 mPa·s or more, and even more preferably 5 mPa·s or more, from the viewpoint of improving storage stability and handleability, and is preferably 1,000 mPa·s or less, more preferably 800 mPa·s or less, even more preferably 400 mPa·s or less, even more preferably 250 mPa·s or less, and even more preferably 200 mPa·s or less, from the viewpoint of improving fluidity. The viscosity of the soil improvement concentrated composition is measured at 25°C for 1 minute using a vibration viscometer (e.g., Viscomate VM-10A-L, manufactured by Sekonic Corporation).

[0043] The soil improving concentrated composition of the present invention can be applied to various soils, but is particularly suitable for agricultural soils, particularly field soils. That is, the soil improving concentrated composition of the present invention is preferably for agricultural use, more preferably for field use.

[0044] The soil improvement concentrate composition of the present invention may contain other optional components, such as thickeners, surfactants, fertilizer components, fungicides, insecticides, plant growth regulators, disinfectants, herbicides, and organic solvents, in addition to the above-mentioned components. The content of the thickener (excluding those corresponding to component (A)) in the soil improvement concentrate composition of the present invention is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably substantially 0% by mass, from the viewpoint of improving fluidity. Examples of surfactants that can be used include those described in JP 2020-196814 A. The content of the optional surfactant (excluding those corresponding to component (C)) in the soil improvement concentrate composition of the present invention is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably substantially 0% by mass, from the viewpoint of improving storage stability and fluidity. The aforementioned components (c2), (c3), (c4), and (c5) are also nonionic surfactants. Therefore, when the soil improvement concentrated composition of the present invention contains any of (c2), (c3), (c4) and (c5), the content of the optional surfactant in the composition is the total content excluding the contents of these components (c2) to (c5) within the above-mentioned preferred range.

[0045] <Method for producing a concentrated soil improvement composition> The present invention provides a method for producing a concentrated soil improvement composition, which includes the steps of mixing (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides [component (B)] with water, and then mixing the resulting mixture (I) with (A) carboxymethyl cellulose and / or a salt thereof [component (A)] to produce mixture (II).

[0046] The present invention also provides a method for producing a soil improving concentrate, which comprises the step of mixing the mixture (I) or the mixture (II) with a polyether compound (C) (component (C)). The method for producing a soil improving concentrate of the present invention preferably comprises the step of mixing the mixture (I) with the polyether compound (C), and then mixing the mixture (I) with component (A) to produce the mixture (III).

[0047] The present invention also provides a method for producing a soil improving concentrate, which comprises mixing the mixture (I), the mixture (II), or the mixture (III) with a (D) hydroxy acid or a salt thereof (component (D)). The method for producing the soil improving concentrate of the present invention preferably comprises the step of mixing the (D) hydroxy acid or a salt thereof with the mixture (II) or the mixture (III) before mixing the component (A) in the method for producing the mixture (II) or the mixture (III), and more preferably comprises the step of mixing the mixture (I) with the component (C), and then mixing the mixture (I) with the component (D), and then further mixing the component (A) to produce a mixture (IV).

[0048] The method for producing a soil improvement concentrated composition of the present invention may be the method for producing a soil improvement concentrated composition of the present invention, comprising the steps of: mixing (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides [component (B)] with water to obtain an aqueous solution containing 11% by mass or more and 45% by mass or less of component (B); and mixing the aqueous solution with (A) carboxymethylcellulose and / or a salt thereof [component (A)].

[0049] The preferred embodiments of the components (A) and (B) used in the method for producing the soil improving concentrated composition of the present invention are the same as the preferred embodiments of the components (A) and (B) of the soil improving concentrated composition of the present invention.

[0050] The method for producing the soil improving concentrated composition of the present invention will be specifically described. However, the method for producing the soil improving concentrated composition of the present invention is not limited to the specific examples. The method for producing the soil improving concentrated composition of the present invention includes step 1 of mixing component (B) with water to obtain an aqueous solution containing component (B), and step 2 of mixing component (A) with the aqueous solution obtained in step 1.

[0051] In step 1, from the viewpoint of improving fluidity, component (B) is mixed with water to obtain an aqueous solution containing component (B) in a concentration of 11% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and even more preferably 27% by mass or more, and from the viewpoint of improving storage stability, 45% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 32% by mass or less.

[0052] In step 2, the aqueous solution obtained in step 1 is mixed with component (A) to obtain the soil improvement concentrated composition of the present invention. The preferred amount of component (A) to be mixed in step 2 can be interpreted as the preferred content of component (A) in the soil improvement concentrated composition of the present invention.

[0053] In the method for producing a concentrated soil improving composition of the present invention, the mass ratio of the amount of component (A) mixed to the amount of component (B) mixed [(A) / (B)] is 0.11 or more, preferably 0.12 or more, more preferably 0.15 or more, and even more preferably 0.17 or more, from the viewpoint of reducing viscosity, and is 0.4 or less, preferably 0.35 or less, more preferably 0.3 or less, even more preferably 0.25 or less, even more preferably 0.2 or less, and even more preferably 0.19 or less, from the viewpoint of improving storage stability.

[0054] In addition, in step 1 or step 2, (C) a polyether compound (component (C)) and / or (D) a hydroxy acid or a salt thereof (component (D)) can be optionally mixed with the aqueous solution. The preferred embodiments of the components (C) and (D) used in the method for producing the soil improvement concentrate of the present invention are the same as the preferred embodiments of the components (C) and (D) in the soil improvement concentrate of the present invention. Furthermore, in the method for producing the soil improvement concentrate of the present invention, the preferred amounts of the components (C) and (D) to be mixed can be interpreted as the amounts to be mixed by replacing the preferred contents of the components (C) and (D) in the soil improvement concentrate of the present invention.

[0055] <Soil Improvement Method> The present invention provides a soil improvement method in which a soil improvement composition prepared by diluting the above-mentioned soil improvement concentrated composition of the present invention with water is sprayed onto soil. Preferred embodiments of the soil improvement concentrated composition used in the soil improvement method of the present invention are the same as those described above for the soil improvement concentrated composition of the present invention. In the following description, the soil improvement composition is also referred to as a spray liquid (hereinafter referred to as the spray liquid of the present invention).

[0056] In the soil improvement method of the present invention, the target soil is preferably soil in cultivated land for growing plants and crops. The target soil in the soil improvement method of the present invention is not particularly limited, but is preferably agricultural soil, especially field soil.

[0057] From the viewpoint of improving economic rationality, the spray solution of the present invention contains the soil improvement concentrated composition of the present invention in an amount of preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 5% by mass or more, even more preferably 8% by mass or more, and from the viewpoint of improving ease of handling during spraying, it is preferably 20% by mass or less, more preferably 12% by mass or less, even more preferably 10% by mass or less. That is, from the same viewpoint, it is preferable that the soil improvement composition of the present invention contains the soil improvement concentrated composition of the present invention in the above-mentioned amount.

[0058] The spray solution of the present invention is preferably prepared by diluting the concentrated soil improvement composition by preferably 2 times or more, more preferably 5 times or more, even more preferably 8 times or more, and even more preferably 10 times or more from the viewpoint of improving ease of handling during dilution, and from the viewpoint of improving economic rationality, by diluting the concentrated soil improvement composition by preferably 1500 times or less, more preferably 1000 times or less, even more preferably 500 times or less, even more preferably 300 times or less, even more preferably 100 times or less, even more preferably 80 times or less, and even more preferably 50 times or less. That is, in the soil improvement method of the present invention, from the same viewpoint, it is preferable to prepare the soil improvement composition by diluting the concentrated soil improvement composition of the present invention at a dilution ratio within the above range.

[0059] The spray solution of the present invention contains component (A) in an amount of preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoint of improving soil improvement performance, and preferably 1.9% by mass or less, more preferably 1% by mass or less, even more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less, from the viewpoint of improving ease of handling during spraying.

[0060] The spray solution of the present invention contains component (B) in an amount of preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of improving ease of handling during spraying, and preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, from the viewpoint of improving economic rationality.

[0061] When the spray solution of the present invention contains component (C), the spray solution of the present invention contains component (C) in an amount of preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoint of improving ease of handling during spraying, and preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, from the viewpoint of improving economic rationality.

[0062] When the spray solution of the present invention contains component (D), the spray solution of the present invention contains component (D) in an amount of preferably 0.00001% by mass or more, more preferably 0.00003% by mass or more, even more preferably 0.0001% by mass or more, from the viewpoint of improving ease of handling during spraying, and preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, from the viewpoint of improving ease of handling during spraying.

[0063] A specific method for applying the spray solution of the present invention to soil in a farm field includes using a sprayer in combination with a tiller or the like and plowing the soil while spraying the spray solution of the present invention.

[0064] In the present invention, the soil improvement composition is applied to soil so that the proportion of component (A) applied per 100 parts by mass of soil is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, even more preferably 0.001 parts by mass or more, and preferably 0.1 parts by mass or less, more preferably 0.05 parts by mass or less, even more preferably 0.03 parts by mass or less, and even more preferably 0.01 parts by mass or less.

[0065] When the soil improving method of the present invention is used to spray the spray solution of the present invention on soil, the spray solution is applied to 1,000 m of soil. ２ The soil improvement composition is applied to the soil so that the amount of component (A) applied is preferably 0.1 kg or more, more preferably 0.5 kg or more, even more preferably 1 kg or more, and preferably 100 kg or less, more preferably 50 kg or less, even more preferably 30 kg or less, and even more preferably 10 kg or less per 10 ...

[0066] The soil improvement method of the present invention can be applied to, for example, soil when converting paddy fields to upland fields, soil after being used as upland fields, or soil in non-cultivated land. The soil improvement method of the present invention can also be applied to, for example, crushed soil such as soil after cultivation, or to soil that was non-cultivated land when non-cultivated land is converted into cultivated land.

[0067] The following are examples of embodiments of the present invention. The matters described in the soil improving concentrated composition, the method for producing the soil improving concentrated composition, and the soil improving method of the present invention can be applied as appropriate to these embodiments.

[0068] <1> A concentrated soil improvement composition comprising: (A) carboxymethyl cellulose and / or a salt thereof [hereinafter referred to as component (A)]; (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides [hereinafter referred to as component (B)]; and water, wherein the content of component (A) in the composition is 2% by mass or more and 15% by mass or less, and the mass ratio of the content of component (A) to the content of component (B) [(A) / (B)] is 0.11 or more and 0.4 or less.

[0069] <2> The degree of substitution per structural unit of the carboxymethyl group of component (A) is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 0.6 or more, even more preferably 0.7 or more, even more preferably 0.8 or more, and preferably 2.5 or less, more preferably 2.0 or less, even more preferably 1.8 or less, even more preferably 1.5 or less. The concentrated soil improvement composition according to <1>.

[0070] <3> The viscosity of a 1% by mass aqueous solution of the component (A) at 25°C is preferably 100 mPa·s or more, more preferably 500 mPa·s or more, even more preferably 1,000 mPa·s or more, still more preferably 2,000 mPa·s or more, and preferably 30,000 mPa·s or less, more preferably 15,000 mPa·s or less, even more preferably 10,000 mPa·s or less, still more preferably 5,000 mPa·s or less, even more preferably 3,500 mPa·s or less, and still more preferably 2,800 mPa·s or less. The soil improvement concentrated composition according to <1> or <2>.

[0071] <4> The soil improvement concentrated composition according to any one of <1> to <3>, wherein the component (B) is preferably one or more inorganic salts selected from sulfates, phosphates, and carbonates, more preferably one or more inorganic salts selected from ammonium sulfate, potassium carbonate, sodium carbonate, and diammonium hydrogen phosphate, and even more preferably ammonium sulfate.

[0072] <5> The soil improvement concentrated composition according to any one of <1> to <4>, wherein the content of component (A) in the soil improvement concentrated composition is 2% by mass or more, preferably 2.5% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, even more preferably 4.5% by mass or more, and 15% by mass or less, preferably 11% by mass or less, more preferably 10% by mass or less, even more preferably 8% by mass or less, and even more preferably 7.5% by mass or less.

[0073] <6> The soil improvement concentrated composition according to any one of <1> to <5>, wherein the content of component (B) in the soil improvement concentrated composition is preferably 11% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, even more preferably 27% by mass or more, and preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, and even more preferably 32% by mass or less.

[0074] <7> The soil improvement concentrated composition according to any one of <1> to <6>, wherein the mass ratio of the content of the component (A) to the content of the component (B) in the soil improvement concentrated composition [(A) / (B)] is 0.11 or more, preferably 0.12 or more, more preferably 0.15 or more, even more preferably 0.17 or more, and is 0.4 or less, preferably 0.35 or less, more preferably 0.3 or less, even more preferably 0.25 or less, even more preferably 0.2 or less, and even more preferably 0.19 or less.

[0075] <8> The concentrated soil improvement composition according to any one of <1> to <7>, which is a liquid concentrated soil improvement composition.

[0076] <9> The soil improvement concentrated composition according to any one of <1> to <8>, containing water in an amount of preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, even more preferably 60% by mass or more, even more preferably 63% by mass or more, and preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 68% by mass or less.

[0077] <10> The soil improvement concentrated composition according to any one of <1> to <9>, further comprising (C) a polyether compound [hereinafter referred to as component (C)].

[0078] <11> The soil improvement concentrated composition according to <10>, wherein the component (C) is preferably one or more polyether compounds (c1) selected from compounds represented by the following general formula (c1), polyoxyalkylene alkyl ethers (c2), polyoxyalkylene sorbitan fatty acid esters (c3), polyoxyalkylene sorbitol fatty acid esters (c4), and polyoxyalkylene fatty acid esters (c5). １ｃ O-(AO) ｎ -R ２ｃ (c1) [wherein, R １ｃ and R ２ｃ are each independently a hydrogen atom or an alkyl or alkenyl group having from 1 to 6 carbon atoms, AO is an alkyleneoxy group having from 2 to 4 carbon atoms, and n is the average number of moles of AO added, which is from 2 to 1,800.

[0079] <12> The soil improvement concentrated composition according to <10> or <11>, wherein the weight-average molecular weight of component (C) is preferably 100 or more, more preferably 200 or more, even more preferably 240 or more, and still more preferably 300 or more, and preferably 50,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, even more preferably 2,000 or less, even more preferably 1,500 or less, even more preferably 1,000 or less, even more preferably 800 or less, and even more preferably 600 or less.

[0080] <13> The soil improvement concentrated composition according to any one of <10> to <12>, wherein the content of component (C) in the soil improvement concentrated composition is preferably 0.1% by mass or more, more preferably 0.25% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.5% by mass or more, even more preferably 2% by mass or more, even more preferably 3% by mass or more, and preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 5% by mass or less, and even more preferably 4% by mass or less.

[0081] <14> The soil improvement concentrated composition according to any one of <1> to <13>, further comprising (D) a hydroxy acid or a salt thereof (hereinafter referred to as component (D)).

[0082] <15> The soil improvement concentrated composition according to <14>, wherein component (D) is at least one selected from the group consisting of malic acid, citric acid, isocitric acid, isopropyl citrate, hydroxymalonic acid, tartaric acid, 3-hydroxy-3-methylglutaric acid, mucic acid, gluconic acid, gallic acid, mevalonic acid, pantoic acid, orsellinic acid, gentisic acid, quinic acid, and salts thereof.

[0083] <16> The soil improvement concentrate composition according to <14> or <15>, containing the component (D) in an amount of preferably 0.001% by mass or more, more preferably 0.003% by mass or more, even more preferably 0.01% by mass or more, even more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, and preferably 5% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less.

[0084] <17> A method for producing a concentrated soil improvement composition, comprising the steps of: (B) mixing one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides with water; and (A) mixing the resulting mixture (I) with carboxymethyl cellulose and / or a salt thereof to produce a mixture (II).

[0085] <18> A method for producing the soil improvement concentrated composition according to <17>, comprising a step of mixing the mixture (I) or the mixture (II) with a polyether compound (C), preferably a step of mixing the mixture (I) with the polyether compound (C), and then mixing the mixture (I) with (A) carboxymethyl cellulose and / or a salt thereof to produce a mixture (III).

[0086] <19> A method for producing the soil improvement concentrated composition according to <17> or <18>, comprising the step of mixing the mixture (I), the mixture (II), or the mixture (III) with a (D) hydroxy acid or a salt thereof (component (D)), preferably mixing the mixture (I) with a (C) polyether compound, and then mixing the mixture (I) with a (D) hydroxy acid or a salt thereof (component (D)), and further mixing with (A) carboxymethyl cellulose and / or a salt thereof to produce a mixture.

[0087] <20> A soil improvement method, comprising: diluting the concentrated soil improvement composition according to any one of <1> to <16> with water to prepare a soil improvement composition; and applying the diluted soil improvement composition to soil.

[0088] <21> The soil improvement method according to <20>, wherein the concentrated soil improvement composition is diluted preferably 2 times or more, more preferably 5 times or more, even more preferably 8 times or more, even more preferably 10 times or more, and preferably 1500 times or less, more preferably 1000 times or less, even more preferably 500 times or less, even more preferably 300 times or less, even more preferably 100 times or less, even more preferably 80 times or less, even more preferably 50 times or less to prepare a soil improvement composition.

[0089] <22> Soil 1,000m ２ The soil improvement method according to <20> or <21>, wherein the soil improvement composition is applied to the soil so that the amount of component (A) applied is preferably 0.1 kg or more, more preferably 0.5 kg or more, even more preferably 1 kg or more, and preferably 100 kg or less, more preferably 50 kg or less, even more preferably 30 kg or less, and still more preferably 10 kg or less per 1000 m² of soil.

[0090] Examples Concentrated soil improvement compositions shown in Tables 1 to 4 were prepared using the ingredients listed below, and the handling (fluidity) and storage stability of the concentrated soil improvement compositions were evaluated. The soil improvement concentrated compositions were also diluted with water to form soil improvement compositions (spray solutions) that had good drainage performance.

[0091] <Ingredients> <Component (A)> A-1: ​​Sodium carboxymethylcellulose, Sunrose F350HC, 1% mass viscosity (25°C) 2,457 mPa·s, degree of substitution 0.95, manufactured by Nippon Paper Industries Co., Ltd. A-2: Sodium carboxymethylcellulose, Sunrose F600MC, 1% mass viscosity (25°C) 4,000 mPa·s, degree of substitution 0.7, manufactured by Nippon Paper Industries Co., Ltd. A-3: Sodium carboxymethylcellulose, CMC Daicel 1390, 1% mass viscosity (25°C) 3,027 mPa·s, degree of substitution 1.6, manufactured by Daicel Miraize Co., Ltd. <Component (A')> A'-1: Hydroxypropyl methylcellulose, Metrose 65SH-15000, manufactured by Shin-Etsu Chemical Co., Ltd. A'-2: Hydroxyethyl cellulose, HEC Daicel SP900, manufactured by Daicel Miraize Co., Ltd.

[0092] <Method for measuring viscosity of a 1% by mass aqueous solution of component (A)> The viscosity of a 1% by mass aqueous solution of component (A) (25°C) was measured using a Brookfield viscometer (TVB-10, manufactured by Toki Sangyo Co., Ltd.) with a rotor M3 at a rotation speed of 30 rpm for a measurement time of 60 seconds.

[0093] <Method for measuring the degree of substitution per structural unit of carboxymethyl group in component (A)> The degree of substitution of component (A) was measured by the following method. ２ 1 mL of O, D ２ O / D ２ SO ４ 1 mL of (molar ratio = 1:1) was added and stirred with a vortex for 1 minute. The mixture was then heated at 90°C for 2 hours, centrifuged (30 rpm, 10 min), and the supernatant was transferred to an NMR tube for 1H NMR measurement. From the obtained spectrum, the integral value of one proton in the sugar backbone and the integral value of two protons in the carboxymethyl group were calculated, and the value obtained by dividing the integral value of the carboxymethyl group / 2 by one proton in the sugar backbone was determined as the degree of substitution of component (A). <NMR measurement conditions> Apparatus: AVANCE NEO400N manufactured by Bruker Magnetic field strength: 400 MHz Probe: iProve (5 mmφ, for solution) 1H, deuterated solvent: D ２O Accumulation count: 128 Waiting time: 30 seconds Data points: 65536 Pulse width: 45° Observation width: 8196 Hz

[0094] <Component (B)> B-1: Ammonium sulfate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-2: Potassium carbonate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-3: Diammonium hydrogen phosphate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-4: Sodium carbonate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-5: Potassium nitrate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-6: Potassium chloride, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. B-7: Dipotassium hydrogen phosphate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.

[0095] <Component (C)> C-1: polyethylene glycol (weight average molecular weight 247), polyethylene glycol 300, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. C-2: polyethylene glycol (weight average molecular weight 383), polyethylene glycol 400, manufactured by Tokyo Chemical Industry Co., Ltd. C-3: polyethylene glycol (weight average molecular weight 573), polyethylene glycol 600, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. C-4: polyethylene glycol (weight average molecular weight 1799), polyethylene glycol 2,000, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. C-5: polyethylene glycol (weight average molecular weight 16524), polyethylene glycol 20,000, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. C-6: polyethylene glycol dimethyl ether (weight average molecular weight 697), manufactured by Sigma-Aldrich C-7: polypropylene glycol (weight average molecular weight 408), polypropylene glycol, diol type, 400, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd. C-8: Polytetramethylene oxide (weight average molecular weight 813), polytetramethylene oxide 650, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. C-9: Polyoxyethylene oleyl ether, average number of moles of oxyethylene added 30, Emulgen 430, manufactured by Kao Corporation <Component (D)> D-1: Citric acid, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0096] Example 1 (1) Preparation of a soil improvement concentrate composition Component (B), water, and optionally component (D) shown in Tables 1 and 2 were added to a 30 mL vial, and the mixture was stirred and dissolved using a vortex mixer or stirrer to obtain an aqueous solution containing component (B). Component (A) was added to this aqueous solution and stirred in the same manner to prepare a soil improvement concentrate composition. Each component was weighed and mixed in an amount that would result in the composition shown in Tables 1 and 2.

[0097] (2) Method for Evaluating Composition State and Storage Stability (i) Evaluation of Composition State Thirty minutes after preparation of the soil improvement concentrated composition, the state of the soil improvement concentrated composition was visually observed. Samples in which the composition flowed when the vial containing the composition was tilted were evaluated as "liquid." On the other hand, samples that immediately separated or samples in which the composition did not flow when tilted were unable to be uniformly collected, and therefore soil improvement evaluation could not be performed. Figure 1 shows the state of the soil improvement concentrated compositions of Example 1-1 and Comparative Example 1-9 as examples of the state of the soil improvement concentrated compositions.

[0098] (ii) Evaluation of fluidity (handleability) 15 g of the soil improvement concentrated composition was placed in a 15 mL vial, and the viscosity of the soil improvement concentrated composition was measured using a vibration viscometer (Viscomate VM-10A-L, manufactured by Sekonic Corporation). Samples in which the composition did not flow when the vial containing the composition was tilted had a viscosity of 1,000 mPa s or more, which was above the measurement limit of the instrument and therefore could not be measured. The lower the viscosity of a soil improvement concentrated composition, the better its handleability.

[0099] (iii) Evaluation method for storage stability 15 g of the soil improvement concentrated composition was placed in a 15 mL vial and placed in a constant temperature bath at 50 ° C. to evaluate the storage stability of the soil improvement concentrated composition. 20 days after placing the vial containing the soil improvement concentrated composition in the constant temperature bath, the total volume of the soil improvement concentrated composition and the volume of the cloudy portion in the vial were measured, and the ratio of the volume of the cloudy portion to the total volume of the soil improvement concentrated composition was calculated. The ratio (volume %) of the volume of the cloudy portion of the soil improvement concentrated composition to the total volume of the soil improvement concentrated composition was evaluated. The higher this volume ratio, the better the storage stability of the soil improvement concentrated composition. A soil improvement concentrated composition with a volume ratio of the cloudy portion of 100 vol% indicates that the composition has not separated. Note that Comparative Example 1-8, which is composed only of component (B), was dissolved transparently, so storage stability was not evaluated. Furthermore, if the volume of the cloudy portion relative to the total volume of the soil improvement concentrated composition became 80% by volume or less within 20 days after the vial containing the soil improvement concentrated composition was placed in the thermostatic bath, the evaluation of storage stability was terminated, and the number of days from the start of the evaluation to the end of the evaluation was indicated in the storage stability column in the table, and furthermore, "-" was entered in the column for the volume of the cloudy portion.

[0100] (3) Evaluation method of soil drainage performance (i) Soil preparation method Arakida soil was sieved into three sizes using 4 mm and 2 mm sieves to ensure uniform particle size. 100 g of Arakida soil (80 g as dry soil) (hereinafter referred to as soil) with a moisture content of approximately 20% was filled into a 100 mL plastic cup with a hole in the bottom and lined with gauze (the surface area of ​​the soil filled in the plastic cup was 0.002 m). ２The soil improvement compositions (spray solutions) were prepared by diluting the concentrated soil improvement compositions shown in Tables 1 and 2 with water. These soil improvement compositions were prepared by diluting the concentrated soil improvement compositions with water so that the content of component (A) in the composition was the concentration of component (A) shown in Tables 1 and 2. The soil improvement compositions were then sprayed onto soil filled in a 100 mL plastic cup so that the amount of component (A) added to the soil was the amount shown in Tables 1 and 2. For example, when a soil improvement composition containing 0.1 mass % of component (A) was sprayed so that the amount of component (A) added was 0.005 mass parts per 100 mass parts of soil, the soil surface area was 0.002 m. ２ In this case, 4 g of the soil improvement composition was added to 1,000 m of soil. ２ The amount of component (A) applied per test was 2 kg. For Comparative Examples 1-2 to 1-5, the soil was prepared by applying only powdered component (A) according to Table 2 to the surface of soil filled in a plastic cup and mixing with a spatula. (ii) Evaluation Method for Drainage Performance: The plastic cup filled with soil was fixed on an electronic balance, and a water tray was placed on the balance. In this state, 25 mL of water was slowly added to the soil three times. The first addition was not counted because the soil absorbed the water, and the second and third additions were evaluated as the first and second additions. The evaluation was based on the time from when water began to flow after addition until 5 g of water was drained (drainage performance). The evaluation result for soil with no additions was set at 100, and a relative value for each test was calculated. The smaller this value (the shorter the time until 5 g of water was drained), the better the soil's drainage performance (i.e., permeability).

[0101]

[0102]

[0103] <Notes> The explanations for *1 to *4 in Tables 1 and 2 are as follows. *1: For the sake of convenience, the column for component (A) also lists component (A'), which is a comparative component to component (A). *2: This is the concentration of component (A) in the soil improvement composition when added to the soil. In Comparative Example 1-8, this shows the concentration of component (B) in the soil improvement composition. *3: This is the amount of component (A) added per 100 parts by mass of soil. In Comparative Example 1-8, this shows the amount of component (B) added per 100 parts by mass of soil. *4: When added to 1,000 m of soil ２ In Comparative Example 1-8, the amount of component (A) applied was 1,000 m of soil. ２ The amount (kg) of component (B) applied per unit area is shown.

[0104] Comparing Examples 1-1 to 1-4 with Comparative Examples 1-2 to 1-5, it was found that spraying a liquid containing component (A), i.e., a soil improvement composition containing component (A), on the soil exhibited higher performance than spraying the same amount of component (A) on the soil in solid form. Furthermore, comparing Examples 1-1 to 1-6, 1-10 to 1-12 with Comparative Examples 1-9 to 1-10, it was found that when the concentration of component (A) in the concentrated soil improvement composition was fixed and the concentration of component (B) was increased, the viscosity decreased but the storage stability deteriorated, and when the mass ratio of (A) / (B) was above or below a certain concentration, the formulation became difficult to handle. Furthermore, comparing Example 1-13 with Comparative Example 1-11, it was found that compositions containing component (A) of 20% by mass or more were difficult to handle from the viewpoint of the viscosity of the composition, even when the mass ratio of (A) / (B) was controlled.

[0105] Example 2 (1) Preparation of Soil Improvement Concentrate Compositions Component (B), water, component (C), and optionally component (D) listed in Tables 3 and 4 were added to a 30 mL vial and stirred and dissolved using a vortex mixer or stirrer to obtain an aqueous solution containing component (B). Component (A) was added to this aqueous solution and stirred in the same manner to prepare a soil improvement concentrate composition. Each component was weighed and mixed in the amount required to achieve the composition listed in Tables 3 and 4. Using this soil improvement concentrate composition, the same procedures as in (i) to (iii) of (2) of Example 1 were carried out to evaluate the condition, fluidity (handling), and storage stability of the soil improvement concentrate composition. Furthermore, the same procedures as in (i) to (ii) of (3) of Example 1 were carried out to evaluate the soil drainage performance of each soil improvement composition. The results of these evaluations are shown in Tables 3 and 4.

[0106]

[0107]

[0108] <Notes> The explanations for *1 to *3 in Tables 3 and 4 are as follows: *1: The concentration of component (A) in the soil improvement composition when added to the soil. *2: The amount of component (A) added per 100 parts by mass of soil. *3: The amount of component (A) added per 1,000 parts by mass of soil. ２ The amount (kg) of component (A) applied per unit area.

[0109] Comparing Examples 2-1 to 2-5 with Reference Example 2-1, soil improvement concentrate compositions containing component (C) in addition to components (A) and (B) tended to have a reduced viscosity compared to soil improvement concentrate compositions containing components (A) and (B) but not (C). This effect was more pronounced when the weight-average molecular weight of component (C) was 2,000 or less. Furthermore, as shown in Examples 2-3 and 2-21 to 2-23, the viscosity of the soil improvement concentrate composition also tended to be reduced when the alkylene group of the polyalkylene glycol of component (C) was a propylene group or a butylene group, and this tendency was more pronounced when the alkylene group of the polyalkylene glycol of component (C) was an ethylene group. Furthermore, the viscosity-reducing effect of the soil improvement concentrate composition was more pronounced when the terminal of the polyalkylene glycol of component (C) was a hydroxyl group than when it was a methyl group. Furthermore, as shown in Example 2-24, the viscosity of the soil improvement concentrate composition tended to be reduced even when a nonionic surfactant in which the alkylene group of the (C) component was an ethylene group was used. Examples 2-9 and 2-16 were the most useful compositions in terms of the soil improvement performance of the soil improvement concentrate composition and the soil improvement composition, as well as the storage stability, fluidity, and solubility upon dilution of the soil improvement concentrate composition. As shown in Examples 1-15 to 1-19 and Examples 2-25 to 2-28, it was also possible to combine various types of salts in the soil improvement concentrate composition and the soil improvement composition. In addition to the soil improvement performance of the soil improvement concentrate composition and the soil improvement composition, as well as the storage stability, fluidity, and solubility upon dilution of the soil improvement concentrate composition, it is also possible to add component (B) as a fertilizer component by controlling the combination of salts.

[0110] Furthermore, when component (A) was used, it took approximately 40 minutes to dissolve powder of component (A) in a liquid to prepare a 0.5% by mass aqueous solution of component (A). However, when the concentrated soil improvement compositions of the Examples in Tables 1 to 4 were dissolved in water to prepare similar aqueous solutions, they all dissolved within 1 minute, making them easy for users to handle.

Claims

1. A concentrated composition for soil improvement comprising (A) carboxymethylcellulose and / or a salt thereof [hereinafter referred to as component (A)], (B) one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates and chlorides [hereinafter referred to as component (B)], and water, wherein the content of component (A) in the composition is 2% by mass or more and 15% by mass or less, and the mass ratio of the content of component (A) to the content of component (B) [(A) / (B)] is 0.11 or more and 0.4 or less.

2. A concentrated soil improving composition as described in claim 1, wherein the degree of substitution per constituent unit of the carboxymethyl group of component (A) is 0.6 or more and 1.8 or less.

3. A concentrated soil improvement composition as described in claim 1 or 2, in which the viscosity of a 1 mass% aqueous solution of component (A) at 25°C is 100 mPa·s or more and 30,000 mPa·s or less.

4. A soil improvement concentrated composition described in any one of claims 1 to 3, wherein the content of component (A) in the soil improvement concentrated composition is 3 mass% or more and 10 mass% or less.

5. A soil improvement concentrated composition described in any one of claims 1 to 4, wherein the content of component (B) in the soil improvement concentrated composition is 11 mass% or more and 45 mass% or less.

6. A concentrated soil improving composition according to any one of claims 1 to 5, further comprising (C) a polyether compound (hereinafter referred to as component (C)).

7. A concentrated soil improving composition as described in claim 6, wherein the weight average molecular weight of component (C) is 5,000 or less.

8. The soil improving concentrated composition according to claim 6 or 7, wherein the component (C) is one or more compounds selected from the group consisting of polyether compounds (c1), polyoxyalkylene alkyl ethers (c2), polyoxyalkylene sorbitan fatty acid esters (c3), polyoxyalkylene sorbitol fatty acid esters (c4), and polyoxyalkylene fatty acid esters (c5), which are selected from the compounds represented by the following general formula (c1): １ｃ O-(AO) ｎ -R ２ｃ (c1) [wherein, R １ｃ and R ２ｃ are each independently a hydrogen atom or an alkyl or alkenyl group having from 1 to 6 carbon atoms, AO is an alkyleneoxy group having from 2 to 4 carbon atoms, and n is the average number of moles of AO added, which is a number of from 2 to 1,800.

9. The concentrated soil improving composition according to any one of claims 1 to 8, further comprising (D) a hydroxy acid or a salt thereof.

10. The concentrated soil improving composition according to claim 9, wherein component (D) is one or more selected from the group consisting of malic acid, citric acid, isocitric acid, isopropyl citrate, hydroxymalonic acid, tartaric acid, 3-hydroxy-3-methylglutaric acid, mucic acid, gluconic acid, gallic acid, mevalonic acid, pantoic acid, orsellinic acid, gentisic acid, quinic acid, and salts thereof.

11. A method for producing a concentrated composition for soil improvement, comprising the steps of: (B) mixing one or more inorganic salts selected from sulfates, phosphates, nitrates, carbonates, and chlorides with water; and (C) mixing the resulting mixture (I) with (A) carboxymethylcellulose and / or a salt thereof to produce mixture (II).

12. A method for producing the concentrated soil improvement composition described in claim 11, comprising the step of mixing the mixture (I) with (C) a polyether compound, and then mixing the mixture (I) with (A) carboxymethyl cellulose and / or a salt thereof to produce a mixture (III).

13. A method for producing a concentrated soil improvement composition according to claim 11 or 12, comprising the steps of mixing the mixture (I) with (C) a polyether compound, mixing the mixture (I) with (D) a hydroxy acid or a salt thereof, and further mixing with (A) carboxymethyl cellulose and / or a salt thereof to produce a mixture (IV).

14. A method for improving soil, comprising the steps of: diluting the concentrated soil improving composition according to any one of claims 1 to 10 with water to prepare a soil improving composition; and spraying the resulting soil improving composition on soil.

15. The method for improving soil according to claim 14, wherein the soil improving composition is prepared by diluting the concentrated soil improving composition by a ratio of 2 to 500.

16. Soil 1,000m ２ The method for improving soil according to claim 14 or 15, wherein the soil improvement composition is applied to soil in an amount of 0.1 kg or more and 10 kg or less of component (A) per application.

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