A soil conditioner and a method of making the same

Abstract

The application relates to the technical field of soil improvement, and provides a soil conditioner and a preparation method thereof.The soil conditioner comprises the following raw materials in proportion by weight: 85-95 parts of coal gangue-based biological material, 10-20 parts of modified straw powder, 5-10 parts of mineral material, 1-4 parts of nutrition regulator and 0.5-2 parts of binder.The soil conditioner provided by the application takes the coal gangue-based biological material as the main component, and is matched with the modified straw powder, and has the effect of efficiently promoting crop growth.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a soil conditioner and its preparation method. Background Technology

[0002] Soil is an important component of the geographical environment, the material basis for agricultural production, and a fundamental resource for ecological environment construction, and its relationship with humankind is inseparable. Currently, the development of technologies to improve infertile soil is receiving increasing attention, among which soil conditioners, as an important means to effectively improve soil quality, have garnered widespread interest.

[0003] Coal gangue, a waste product generated during coal mining and processing, is one of the largest industrial solid wastes in terms of emissions. However, biological processing of coal gangue yields bio-based materials rich in organic matter, which can be used in soil conditioners. This is economical and environmentally friendly, improving soil structure, regulating soil pH, enhancing soil fertility, and ultimately increasing crop yields. Similarly, straw powder contains cellulose, hemicellulose, and lignin, as well as essential plant nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium. It increases soil organic matter and improves soil fertility. Furthermore, the utilization of straw powder realizes the resource utilization of agricultural waste, reducing agricultural production costs and promoting sustainable agricultural development. Despite these advantages, straw powder in soil conditioners still suffers from agglomeration and poor dispersibility. In particular, the poor compatibility between straw powder and activated coal gangue bio-based materials hinders their full soil-improving effect.

[0004] Patent CN 118272096 A discloses a coal gangue soil conditioner, its preparation method, and its application. The main components of the coal gangue soil conditioner disclosed in this application include coal gangue powder, corn stalk powder, livestock and poultry manure, compound microbial agents, and high-molecular water-absorbing and water-retaining particles. However, the composition of this application is relatively complex, and the application does not address how to solve the problem of poor dispersibility of corn stalk powder.

[0005] Therefore, there is an urgent need in the market for a soil conditioner with coal gangue bio-based material as the main component, which, when combined with modified straw powder, can effectively promote crop growth. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention uses coal gangue-based biomaterials as the main raw material to design and synthesize modified straw powder, and combines it with mineral materials, nutrient regulators and binders to granulate and obtain a soil conditioner that has a highly efficient effect on promoting crop growth.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides a soil conditioner comprising the following raw materials: 85-95 parts of coal gangue-based biomaterial, 10-20 parts of modified straw powder, 5-10 parts of mineral material, 1-4 parts of nutrient regulator, and 0.5-2 parts of binder.

[0008] In some embodiments of the present invention, the preparation method of the coal gangue-based biomaterial includes the following steps: S1. Crush the coal gangue and ball mill it to obtain coal gangue powder for later use; S2. Mix the natural organic acid and deionized water, stir to obtain a liquid, mix the liquid with the coal gangue powder from step S1, stir to obtain product 1 for later use; the natural organic acid is fulvic acid or alginic acid. S3. Add biological enzyme and deionized water to product 1 from step S2, and react under aerobic conditions at 30-45℃ for 13-15 days to obtain product 2 for later use. S4. Add alkaline nitrogen-containing organic matter to product 2 from step S3, and react under aerobic conditions at 30-45℃ for 20-22 days to obtain product 3 for later use. S5. Add microorganisms to product 3 from step S4 and ferment aerobically at 30-45℃ for 13-15 days to obtain coal gangue bio-based material.

[0009] In step S1, the particle size of the coal gangue powder is 20-80 mesh. The concentration of the liquid in step S2 is 25-35 g / L; the mass ratio of the coal gangue powder to the liquid in step S2 is 1: (0.001-0.005); The bioenzyme mentioned in step S3 is one or more of protease, cellulase, and ligninase; the coal in step S2 The mass ratio of gangue powder to the bio-enzyme in step S3 is 1:(0.001-0.01). The alkaline nitrogen-containing organic matter mentioned in step S4 is one of soybean protein powder, amino acid waste liquid, and protein waste liquid. Several types; the mass ratio of coal gangue powder in step S2 to alkaline nitrogen-containing organic matter in step S4 is 1:(0.001-0.05); The microorganisms mentioned in step S5 are one or more of Bacillus subtilis, Bacillus natto, actinomycetes, and lactic acid bacteria; The mass ratio of coal gangue powder in step S2 to microorganisms in step S5 is 1:(0.001-0.01).

[0010] The applicant first modifies coal gangue powder by adding a certain concentration of fulvic acid aqueous solution. This solution is rich in functional groups and has strong chemical activity, enabling efficient activation of the organic matter in the coal gangue powder. Further, the applicant adds a certain amount of bio-enzyme, which accelerates the breaking of chemical bonds in the coal gangue, synergistically modifying the coal gangue powder with fulvic acid. Simultaneously, the applicant adds a certain amount of deionized water to humidify the environment, providing suitable conditions for the enzyme's catalytic action and increasing the contact opportunity between the enzyme and the organic matter in the coal gangue. Finally, the above product is modified with low-cost alkaline nitrogen-containing substances and microorganisms to obtain coal gangue bio-based materials. This significantly increases the organic matter content in the coal gangue, enhances the soil conditioner's water and fertilizer retention capacity, and ultimately improves crop yield.

[0011] In some embodiments of the present invention, the method for preparing the modified straw powder includes the following steps: (1) Mix straw powder and starch, ball mill at 300-500 rpm for 1-2 hours, dry, and obtain a mixture for later use; (2) Add dodecyl dimethyl betaine to the reaction vessel, add deionized water, adjust pH to 5-6.5, stir, add the mixture from step (1), stir, filter, dry, and obtain the product for later use; (3) Mix diisopropyl di(triethanolamine) titanate and isopropanol, stir, add the product from step (2), stir for 2-3 hours, filter, and dry to obtain modified straw powder.

[0012] In some embodiments of the present invention, in step (1), the mass ratio of straw powder to starch is 1:(0.3-0.5).

[0013] Preferably, in step (1), the mass ratio of straw powder to starch is 1:0.4.

[0014] In some embodiments of the present invention, in step (2), the mass ratio of the mixture to dodecyl dimethyl betaine is 1:(0.08-0.12).

[0015] Preferably, in step (2), the mass ratio of the mixture to dodecyl dimethyl betaine is 1:0.1.

[0016] In some embodiments of the present invention, in step (3), the mass ratio of the product to diisopropyl di(triethanolamine)titanate is 1:(0.07-0.11).

[0017] Preferably, in step (3), the mass ratio of the product to diisopropyl di(triethanolamine)titanate is 1:0.1.

[0018] Straw powder, as a natural plant fiber powder, can increase soil organic matter, improve soil structure, enhance soil water and fertilizer retention capacity, and promote crop growth. However, straw powder itself has problems such as easy agglomeration and poor dispersibility. In addition, the strong hydrophilicity of the surface of straw powder makes it incompatible with the surface properties of coal gangue-based biomaterials, resulting in poor dispersibility of straw powder in soil conditioners with coal gangue-based biomaterials as the main component.

[0019] To address the aforementioned problems with straw powder, the applicant first used ball milling to mix straw powder with starch. Starch is rich in organic matter, providing nutrients and enhancing water retention capacity. Furthermore, the increased organic matter content improves the compatibility between straw powder and coal gangue-based biomaterials. Further, the applicant introduced the surfactant dodecyl dimethyl betaine to balance the hydrophilic and hydrophobic characteristics of the mixture surface, further improving the compatibility between the mixture and coal gangue-based biomaterials. Even further, the applicant selected a specific titanate coupling agent, di(triethanolamine)... Diisopropyl titanate modifies the above product. Di(triethanolamine)diisopropyl titanate reduces the van der Waals forces between particles by forming stable chemical bonds with the product surface, thereby inhibiting agglomeration. Furthermore, the titanate coupling agent has good stability, which can give the modified straw powder good physical and chemical stability. In addition, the applicant unexpectedly discovered that di(triethanolamine)diisopropyl titanate may be able to generate intermolecular interactions such as hydrogen bonding and electrostatic interactions with dodecyl dimethyl betaine, thereby improving the stability of the modified straw powder to a certain extent.

[0020] In some embodiments of the present invention, the mineral material is one or more of zeolite, attapulgite, and sepiolite.

[0021] In some embodiments of the present invention, the nutrient regulator is urea.

[0022] In some embodiments of the present invention, the adhesive is polyacrylamide.

[0023] In another aspect, the present invention provides a method for preparing the soil conditioner described in the above technical solution, comprising the following steps: Mix gangue-based biomaterials, modified straw powder, mineral materials and nutrient regulators, stir for 10-20 minutes, grind through a 40-60 mesh sieve, add binder, stir for 20-30 minutes, and granulate to obtain soil conditioner.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses coal gangue-based biomaterials as the main raw material to design and synthesize modified straw powder, and combines it with mineral materials, nutrient regulators and binders to granulate a soil conditioner that has the effect of effectively promoting crop growth.

[0025] (2) The present invention crushes and ball-mills coal gangue and then combines it with humic acid, biological enzymes, alkaline nitrogen-containing organic matter and organic matter to obtain a coal gangue bio-based material, which is environmentally friendly and greatly increases the organic matter content in coal gangue, thereby increasing crop yield.

[0026] (3) The present invention first mixes straw powder with starch, and then introduces surfactants dodecyl dimethyl betaine and diisopropyl di(triethanolamine) titanate to modify the straw powder, so that the straw powder has good dispersibility and compatibility with coal gangue-based biomaterials, and also improves the stability of the straw powder, thereby enabling the modified straw powder to improve soil structure, improve soil water and fertilizer retention capacity and promote crop growth more efficiently. Detailed Implementation

[0027] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0028] In the following examples and comparative examples, except for the modified straw powder, all other compounds and related reagents used were commercially available. Specifically, the protease was GFY-3308, the cellulase was 9012-54-8, the Bacillus subtilis was Bacillus subtilis CICC 10275, deposited at the China Industrial Microbiological Culture Collection Center, the actinomycete had the accession number CPCC206517, deposited at the China Pharmaceutical Microbiological Culture Collection Center, the corn straw powder had a particle size of 20 mesh, the starch was corn starch purchased from Chengdu Yuang Chemical Co., Ltd., and the polyacrylamide was purchased from Suzhou Shengyu Industry & Trade Co., Ltd.

[0029] Preparation Example 1 The synthesis method of coal gangue bio-based material A includes the following steps: S1. Crush 1 kg of coal gangue and ball mill it to 50 mesh to obtain coal gangue powder for later use. S2. Mix 3g of fulvic acid and 100ml of deionized water, stir to obtain a liquid, mix 1.5g of the liquid with 500g of coal gangue powder from step S1, stir evenly to obtain product 1 for later use. S3. Add 2.5g of biological enzyme and 150g of deionized water to product 1 from step S2, and react under aerobic conditions at 40℃ for 14 days to obtain product 2 for later use. The bioenzyme is a mixture of protease and cellulase in a mass ratio of 1:1. S4. Add 12.5g of soybean protein powder to product 2 from step S3, and react under aerobic conditions at 40℃ for 21 days to obtain product 3 for later use. S5. Add 2.5g of microorganisms to product 3 from step S4 and ferment aerobically at 40℃ for 14 days to obtain coal gangue bio-based material A. The microorganisms are a mixture of Bacillus subtilis and actinomycetes in a mass ratio of 1:0.5.

[0030] Preparation Example 2 Coal gangue bio-based material B is implemented in the same way as coal gangue bio-based material A, except that the mass of fulvic acid in step S2 is replaced with 1.5g.

[0031] Preparation Example 3 Coal gangue bio-based material C is implemented in the same way as coal gangue bio-based material A, except that the mass of the liquid in step S2 is replaced with 3g.

[0032] Preparation Example 4 Coal gangue bio-based material D is implemented in the same way as coal gangue bio-based material A, except that the mass of the bio-enzyme in step S3 of step S2 is replaced with 0.3g.

[0033] Preparation Example 5 The synthesis method of modified straw powder A includes the following steps: (1) Mix 20g of corn stalk powder and 8g of corn starch, ball mill at 400rpm for 1.5h, dry, and obtain the mixture for later use; (2) Add 1.5g of dodecyl dimethyl betaine to the reaction vessel, add 50ml of deionized water, adjust the pH to 6, stir evenly, add 15g of the mixture from step (1), stir evenly, filter, dry, and obtain the product for later use. (3) Mix 1g of diisopropyl di(triethanolamine) titanate and 20ml of isopropanol, stir evenly, add 10g of the product from step (2), stir for 2.5h, filter, and dry to obtain modified straw powder A.

[0034] Preparation Example 6 Modified straw powder B is implemented in the same way as modified straw powder A, except that the mass of corn starch in step (1) is replaced with 5g.

[0035] Preparation Example 7 Modified straw powder C is implemented in the same way as modified straw powder A, except that the mass of dodecyl dimethyl betaine in step (2) is replaced with 1g.

[0036] Preparation Example 8 Modified straw powder D is implemented in the same way as modified straw powder A, except that the mass of diisopropyl di(triethanolamine) titanate in step (3) is replaced with 0.5g.

[0037] Example 1 A soil conditioner, by weight, comprises the following raw materials: 90 parts of coal gangue-based biomaterial A, 15 parts of modified straw powder A, 8 parts of mineral materials, 2.5 parts of urea, and 1.5 parts of polyacrylamide. The mineral material is a mixture of zeolite, attapulgite, and sepiolite in a mass ratio of 1:1:1.

[0038] The preparation method of the soil conditioner in this embodiment includes the following steps: Mix gangue-based biomaterials, modified straw powder A, mineral materials and urea, stir for 15 minutes, grind through a 50-mesh sieve, add polyacrylamide, stir for 25 minutes, and granulate (particle size 3 mm) to obtain the soil conditioner.

[0039] Example 2 A soil conditioner, by weight, comprises the following raw materials: 85 parts of coal gangue-based biomaterial A, 10 parts of modified straw powder A, 5 parts of mineral material, 1 part of urea, and 0.5 parts of polyacrylamide. The mineral material is zeolite.

[0040] The preparation method of the soil conditioner in this embodiment includes the following steps: Mix gangue-based biomaterials, modified straw powder A, mineral materials and urea, stir for 10 minutes, grind through a 40-mesh sieve, add polyacrylamide, stir for 20 minutes, and granulate (particle size 3 mm) to obtain the soil conditioner.

[0041] Example 3 A soil conditioner, by weight, comprises the following raw materials: 95 parts of coal gangue-based biomaterial A, 20 parts of modified straw powder A, 10 parts of mineral material, 4 parts of urea, and 2 parts of polyacrylamide. The mineral material is attapulgite.

[0042] The preparation method of the soil conditioner in this embodiment includes the following steps: Mix gangue-based biomaterials, modified straw powder A, mineral materials and urea, stir for 20 minutes, grind through a 60-mesh sieve, add polyacrylamide, stir for 30 minutes, and granulate (particle size 3 mm) to obtain the soil conditioner.

[0043] Example 4 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that coal gangue bio-based material B is used to replace coal gangue bio-based material A in an equal amount.

[0044] Example 5 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that coal gangue bio-based material C is used to replace coal gangue bio-based material A in an equal amount.

[0045] Example 6 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that coal gangue bio-based material D is used to replace coal gangue bio-based material A in an equal amount.

[0046] Example 7 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that modified straw powder A is replaced by an equal amount of modified straw powder B.

[0047] Example 8 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that modified straw powder A is replaced by an equal amount of modified straw powder C.

[0048] Example 9 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that modified straw powder A is replaced by modified straw powder D in an equal amount.

[0049] Example 10 This embodiment provides a soil conditioner and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that coal gangue powder is used to replace coal gangue-based biomaterials in equal amounts.

[0050] The preparation method of coal gangue powder is the same as step S1 in preparation example 1.

[0051] Comparative Example 1 This comparative example provides a soil conditioner and its preparation method. The specific implementation method is the same as in Example 1, except that corn straw powder replaces modified straw powder A in an equal amount.

[0052] Performance testing The effects of the soil conditioners described in Examples 1-10 and Comparative Example 1 were tested, and the test results are shown in Table 1. Each group was tested three times, and the average value was taken.

[0053] By comparing the soil conditioner application experiments of the examples and comparative examples, the test crop was sugarcane. The experimental method was to conduct a field fertilization comparison of equal area. The experiment adopted a randomized block design with 11 treatments: the control group was fertilized with 50 kg / mu of compound fertilizer (15-5-10) according to local custom. In the examples and comparative examples, 10 wt% of soil conditioner was added on the basis of adding the same amount of compound fertilizer as the control group.

[0054] The effectiveness of soil conditioners is judged by testing the yield increase rate of sugarcane. The yield increase rate is calculated based on the control group as a benchmark. Yield increase rate (%) = (sugarcane yield of experimental group - sugarcane yield of control group) / sugarcane yield of control group × 100%.

[0055] Table 1

[0056] As shown in Table 1, the soil conditioners in Examples 1-3 of this invention all exhibited high yield increases, meaning they effectively promoted crop growth. However, Examples 4-6 altered the proportions of key components added during the synthesis of the coal gangue bio-based material, resulting in lower organic matter content and a significant decrease in crop yield. Examples 7-9 changed the proportions of starch, dodecyl dimethyl betaine, and diisopropyl di(triethanolamine) titanate in the modified straw powder synthesis, reducing the dispersibility of the modified straw powder and its compatibility with the coal gangue bio-based material, thus decreasing the crop growth-promoting effect of the soil conditioner. Example 10 involved replacing the coal gangue bio-based material with an equal amount of coal gangue powder; the organic matter content of the coal gangue powder differed significantly from that of the bio-based material, leading to a significant decrease in crop yield. Comparative Example 1 used corn straw powder to replace modified straw powder A in an equal amount, and tests revealed that the prepared soil conditioner showed poor crop growth-promoting effects.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A soil conditioner, characterized in that, By weight, the soil conditioner comprises the following raw materials: 85-95 parts of coal gangue-based biomaterials, 10-20 parts of modified straw powder, 5-10 parts of mineral materials, 1-4 parts of nutrient regulators, and 0.5-2 parts of binders.

2. The soil conditioner according to claim 1, characterized in that, The preparation method of the coal gangue-based biomaterial includes the following steps: S1. Crush the coal gangue and ball mill it to obtain coal gangue powder for later use; S2. Mix natural organic acid and deionized water, stir to obtain a liquid, mix the liquid with the coal gangue powder from step S1, stir to obtain product 1 for later use. The natural organic acid is fulvic acid or alginic acid; S3. Add biological enzyme and deionized water to product 1 from step S2, and react under aerobic conditions at 30-45℃ for 13-15 days to obtain product 2 for later use. S4. Add alkaline nitrogen-containing organic matter to product 2 from step S3, and react under aerobic conditions at 30-45℃ for 20-22 days to obtain product 3 for later use. S5. Add microorganisms to product 3 from step S4 and ferment aerobically at 30-45℃ for 13-15 days to obtain coal gangue bio-based material.

3. The soil conditioner according to claim 1, characterized in that, The preparation method of the modified straw powder includes the following steps: (1) Mix straw powder and starch, ball mill at 300-500 rpm for 1-2 hours, dry, and obtain a mixture for later use; (2) Add dodecyl dimethyl betaine to the reaction vessel, add deionized water, adjust pH to 5-6.5, stir, add the mixture from step (1), stir, filter, dry, and obtain the product for later use; (3) Mix diisopropyl di(triethanolamine) titanate and isopropanol, stir, add the product from step (2), stir for 2-3 hours, filter, and dry to obtain modified straw powder.

4. The soil conditioner according to claim 3, characterized in that, In step (1), the mass ratio of straw powder to starch is 1:(0.3-0.5).

5. The soil conditioner according to claim 3, characterized in that, In step (2), the mass ratio of the mixture to dodecyl dimethyl betaine is 1:(0.08-0.12).

6. The soil conditioner according to claim 3, characterized in that, In step (3), the mass ratio of the product to diisopropyl di(triethanolamine)titanate is 1:(0.07-0.11).

7. The soil conditioner according to claim 1, characterized in that, The mineral material is one or more of zeolite, attapulgite, and sepiolite.

8. The soil conditioner according to claim 1, characterized in that, The nutritional regulator is urea.

9. The soil conditioner according to claim 1, characterized in that, The adhesive is polyacrylamide.

10. A method for preparing a soil conditioner according to any one of claims 1-9, characterized in that, Includes the following steps: Mix gangue-based biomaterials, modified straw powder, mineral materials and nutrient regulators, stir for 10-20 minutes, grind through a 40-60 mesh sieve, add binder, stir for 20-30 minutes, and granulate to obtain soil conditioner.

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