Composite soil conditioner and application thereof

Abstract

The invention discloses a composite soil conditioner and application thereof, and belongs to the technical field of saline-alkali soil treatment, the soil conditioner comprises the following components by weight: 10-30 parts of fly ash, 5-15 parts of carbide slag, 30-50 parts of water, and 30-50 parts of a microbial coated fertilizer. According to the method, the chelating agent and the surfactant are used for leaching the fly ash to remove heavy metals and organic harmful substances in the fly ash, the fly ash suspension is activated by adopting microwave, ultrasonic wave and ultraviolet laser treatment, and the carbide slag is added for solidifying residual heavy metal ions, so that the bioavailability and mobility of the heavy metal ions in the soil are reduced; by adding the microbial coated fertilizer, the soil fertility and activity are enhanced, nutrient circulation in soil and plant root growth are promoted, the yield and quality of crops are improved, and the prepared soil conditioner can change the soil structure, increase the soil aggregate content, enhance the air permeability and water permeability and improve the quality of the crops. The soil quality and the crop yield are improved while long-term effective improvement of the saline-alkali soil is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land treatment, and in particular relates to a composite soil conditioner and application thereof. Background Art

[0002] my country's saline-alkali land is roughly distributed in the northwest, northeast, north China and coastal areas. Saline-alkali land refers to land with a large amount of salt in the soil, which leads to a decrease in soil fertility and inhibits the growth of crops. The main causes of its formation include natural and human factors. In terms of nature, in arid and semi-arid areas, under the action of evaporation, the water on the land is evaporated into water vapor and discharged into the air, while the salt in the water cannot be discharged and remains in the soil. As time goes by, the salt in the soil continues to accumulate and the concentration becomes higher and higher. Human factors include unreasonable irrigation, industrial wastewater discharge and agricultural production activities. For example, in some areas, the salt content of irrigation water is high and flooding has been used for a long time, which causes the salt in the soil to accumulate continuously; industrial wastewater discharge will also bring a large amount of salt into the soil.

[0003] At present, the improvement measures for saline-alkali land mainly include physical improvement, chemical improvement, biological improvement and comprehensive improvement. Physical improvement effectively reduces the salt content of the soil surface through deep plowing, loosening the soil, drainage and salt washing, creating favorable conditions for the establishment of microbial communities and crop growth. Covering with organic matter such as crop residues increases the organic matter content of the soil, improves the soil structure, and increases the soil's water retention capacity. Chemical improvement uses chemical substances such as gypsum and ammonium sulfate to adjust the soil pH, reduce the exchangeable sodium content in the soil, and alleviate the inhibitory effect of salt and alkali on crop growth. Biological improvement uses the plant's own salt tolerance and improvement effect, such as planting salt-tolerant plants such as Suaeda salsa and alfalfa, to improve soil structure and affect the soil microenvironment through root secretion substances.

[0004] However, there are still many difficult problems in the process of saline-alkali land improvement. For example, the existing single improvement method is difficult to effectively remove heavy metals and organic harmful substances in the soil, and cannot fully reduce the biological effectiveness and mobility of heavy metal ions in the soil, thereby failing to reduce the potential harm to the ecosystem. In terms of improving soil structure, it is difficult to increase the content of soil aggregates and enhance soil permeability and water permeability. At the same time, in terms of improving soil fertility and activity, the existing conditioners are effective in promoting nutrient circulation in the soil and plant root growth. Therefore, the use effect of existing conditioners is not ideal. In view of this, it is necessary to provide a composite soil conditioner that can combine the advantages of physical improvement, chemical improvement and biological improvement. Summary of the invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the composite soil conditioner of the present invention includes fly ash, carbide slag, water, and microbial coated fertilizer. Through the synergistic effect of each component, the function of improving the soil structure of saline-alkali land, enhancing fertility and removing harmful substances is achieved.

[0006] In order to achieve the above purpose, the following technical scheme is adopted: the present invention provides a composite soil conditioner, comprising the following components in parts by weight: 10-30 parts of fly ash, 5-15 parts of carbide slag, 30-50 parts of water, and 30-50 parts of microbial coated fertilizer.

[0007] Furthermore, the composite soil conditioner is prepared by the following steps:

[0008] S1. dissolving a chelating agent and a surfactant in deionized water to obtain an eluent, then adding fly ash to the eluent, stirring for 2-4 hours, filtering, adding water to the eluent fly ash to obtain a fly ash suspension, and then subjecting the fly ash suspension to microwave treatment, ultrasonic treatment and ultraviolet laser treatment to activate the fly ash suspension to obtain an activated fly ash suspension;

[0009] S2. Mix the activated fly ash suspension with carbide slag and microbial coated fertilizer, stir evenly, and obtain the composite soil conditioner.

[0010] Furthermore, the microbial coated fertilizer is prepared by the following steps:

[0011] a. The livestock and poultry manure, corn straw and wheat straw are mixed and composted, and fermented for 30-40 days, to which urea, diammonium phosphate, potassium sulfate and potassium humate are added, and mixed to obtain an organic fertilizer raw material;

[0012] b. Add pyridinium cationic bromide to deionized water, then add D-fructose-1,6-dicalcium diphosphate, stir at 80-100°C for 1-3h, then add 0.5mol / L sodium hydroxide solution, continue stirring for 2-3h, remove water under reduced pressure, add anhydrous ethanol to dissolve, filter, remove ethanol from the filtrate under reduced pressure, and obtain D-fructose-1,6-dicalcium diphosphate ionic liquid;

[0013] c. Grind the vermiculite into 200 mesh powder, immerse it in a 2mol / L nitric acid solution for 1-3h, then filter it, wash it with water until the filtrate is neutral, and dry it to obtain acidified vermiculite powder. Then add the acidified vermiculite powder to deionized water, stir it evenly to form an acidified vermiculite suspension with a mass fraction of 5%-10%, dissolve D-fructose-1,6-dicalcium diphosphate ionic liquid in deionized water to obtain an ionic liquid solution with a mass fraction of 8%-12%, and drop the ionic liquid solution into the acidified vermiculite suspension. While dropping, perform ultrasonic-assisted dispersion. After reacting at 80°C for 3h, filter out the precipitate, dry it, and grind it into 200 mesh powder to obtain intercalated modified vermiculite powder;

[0014] d. Add water to corn starch to prepare starch milk, heat to 70-80°C, add intercalated modified vermiculite powder and stir continuously to obtain starch paste, then spray the starch paste evenly on the surface of fertilizer particles through a nozzle, dry at 50-60°C for 30-60min, spray the composite microbial liquid evenly on the surface of the coated and dried fertilizer particles through a spray device, dry at 30-40°C for 2-5h, and obtain the microbial coated fertilizer.

[0015] Furthermore, the pyridinium type cationic bromide salt is one of 1-ethyl-1-methylpiperidinium bromide salt, 1-propyl-1-methylpiperidinium bromide salt and 1-butyl-1-methylpiperidinium bromide salt.

[0016] Furthermore, the composite microbial bacterial liquid is prepared by mixing Paecilomyces lilacinus, Sphingomonas oligophenolica, Bacillus megaterium, Paenibacillus jelly-like, Bacillus licheniformis, Bacillus megaterium and Bacillus brevis in a ratio of 1:1:2:1:3:2:2, and inoculating, activating, fermenting and diluting the mixture. The total colony count of the composite microbial bacterial liquid is ≥5×10 9 CFU / mL.

[0017] Furthermore, the organic fertilizer raw material includes the following components in parts by weight: 40-60 parts of livestock and poultry manure, 10-20 parts of corn straw, 10-20 parts of wheat straw, 10-20 parts of urea, 3-10 parts of diammonium phosphate, 5-12 parts of potassium sulfate and 5-10 parts of potassium humate.

[0018] Furthermore, in step b, the mass ratio of pyridinium cationic bromide, deionized water, D-fructose-1,6-diphosphate dicalcium salt and sodium hydroxide solution is 1:30-40:1-2:2-5.

[0019] Furthermore, in the step c, the mass ratio of the ionic liquid solution to the acidified vermiculite suspension is 1:2-3; and in the step d, the mass ratio of the corn starch, water and intercalated modified vermiculite powder is 5:30-50:1-2.

[0020] Furthermore, the chelating agent is one of ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and aminotrimethylenephosphonic acid, and the surfactant is one of nonylphenol polyoxyethylene ether, sodium dodecylbenzene sulfonate, sodium dodecyl alcohol ether sulfate and dodecylphenol polyoxyethylene ether.

[0021] Furthermore, the eluent comprises the following components in parts by weight: 1-3 parts of a chelating agent, 1-3 parts of a surfactant, and 80-100 parts of deionized water.

[0022] Furthermore, the power of the microwave treatment is 500-800W, and the treatment time is 10-15min; the frequency of the ultrasonic treatment is 20-40kHz, and the treatment time is 15-20min; the power of the ultraviolet laser treatment is 5-10W, and the treatment time is 5-10min.

[0023] The present invention also provides an application of a composite soil conditioner in improving saline-alkali land.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention uses chelating agents and surfactants to wash fly ash, which can remove heavy metals and organic harmful substances in the fly ash. The fly ash suspension is activated by microwave, ultrasonic and ultraviolet laser treatment. The residual heavy metal ions are further solidified by adding calcium carbide slag, and their biological effectiveness and mobility in the soil are reduced, thereby reducing potential harm to the ecosystem. The addition of microbial coated fertilizers enhances soil fertility and activity. These bacteria can promote nutrient circulation in the soil and plant root growth, thereby improving crop yield and quality. The present invention uses physical, chemical and biological methods to prepare a soil conditioner that can change soil structure, increase soil aggregate content, enhance air permeability and water permeability, and allow salt ions to be slowly carried away by water through subsequent irrigation, forming a virtuous cycle, achieving long-term effective improvement of saline-alkali land while improving soil quality and crop yield;

[0026] (2) The present invention intercalates acidified vermiculite with D-fructose-1,6-diphosphate dicalcium salt ionic liquid, and the vermiculite has the advantages of large specific surface area, adjustable pore size, and environmental friendliness; the adsorption of microorganisms is enhanced; D-fructose-1,6-diphosphate dicalcium salt exists between the intercalated vermiculite layers, and the D-fructose-1,6-diphosphate dicalcium salt has multiple water-based groups, which improves the water and fertilizer retention effect of the soil conditioner; the modified vermiculite can be dispersed between starch molecules to form a skeleton structure, and when the starch paste is dried to form a film, it plays a role in enhancing the mechanical strength of the coating; and the surface of the modified vermiculite is charged and has surface activity, and can form electrostatic interactions with starch molecules, which helps to evenly disperse starch molecules in the solution and reduce aggregation and precipitation between starch molecules, thereby promoting the film formation of corn starch in organic fertilizer raw materials;

[0027] (3) The present invention uses ionic liquids, and the cations in the ionic liquids are exchanged with the cations between the vermiculite layers, so that the distance between the vermiculite layers becomes larger. The ionic liquids have good ion exchange capacity and adsorption performance. Therefore, when the fertilizer is applied to the soil, due to the presence of the ionic liquids, the coating layer has a slow-release effect on the fertilizer, thereby extending the effective action time of the fertilizer and reducing the loss and waste of nutrients. In addition, the ionic liquids prepared by the present invention have a pH response effect. When the pH value of the saline-alkali land is high, the acidic groups in the ionic liquids gradually dissociate and release hydrogen ions, thereby lowering the pH value of the soil and reducing the alkalinity of the soil. In addition, the ionic liquids can form complexes with nutrients such as phosphorus, iron, and zinc in the soil to prevent these nutrients from being fixed by the soil, thereby improving their solubility and effectiveness in the soil. They can also bind heavy metal ions to provide a good environment for the growth of microorganisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The effective viable bacteria count test results of each embodiment, comparative example and control group of the present invention;

[0029] Figure 2 The heavy metal content test results of various embodiments, comparative examples and control groups of the present invention are shown in FIG.

[0030] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0033] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

[0034] The Paecilomyces lilacinus was purchased from Shanghai Xuanke Biotechnology Co., Ltd.

[0035] The Sphingomonas oligophenolica was purchased from Nuoan Gene Technology (Wuhan) Co., Ltd.

[0036] The Bacillus megaterium, with a collection number of SHBCC D73423, was purchased from Shanghai Collection Biotechnology Center.

[0037] The jelly-like Paenibacillus megaterium, with a collection number of SHBCC D53182, was purchased from Shanghai Collection Biotechnology Center.

[0038] The Bacillus licheniformis, with a collection number of SHBCC D51106, was purchased from Shanghai Collection Biotechnology Center.

[0039] The Bacillus megaterium, with a collection number of SHBCC D73423, was purchased from Shanghai Collection Biotechnology Center.

[0040] The Bacillus pumilus, with a collection number of SHBCC D53157, was purchased from Shanghai Collection Biotechnology Center.

[0041] Example 1

[0042] A composite soil conditioner comprises the following components in parts by weight: 30 parts of fly ash, 15 parts of carbide slag, 50 parts of water and 50 parts of microbial coated fertilizer.

[0043] The composite soil conditioner is prepared by the following steps:

[0044] S1. The chelating agent and the surfactant are dissolved in deionized water to obtain an eluent, and then fly ash is added to the eluent, stirred for 4 hours, filtered, and the fly ash after elution is mixed with water to obtain a fly ash suspension, and then the fly ash suspension is activated by microwave treatment (power 800W, treatment time 15min), ultrasonic treatment (frequency 40kHz, treatment time 20min) and ultraviolet laser treatment (power 10W, treatment time 10min) to obtain an activated fly ash suspension;

[0045] S2. Mix the activated fly ash suspension with carbide slag and microbial coated fertilizer, stir evenly, and obtain the composite soil conditioner.

[0046] The microbial coated fertilizer is prepared by the following steps:

[0047] a. The livestock and poultry manure, corn stalks and wheat stalks were mixed and composted, and fermented for 40 days, to which urea, diammonium phosphate, potassium sulfate and potassium humate were added, and mixed to obtain an organic fertilizer raw material;

[0048] b. Add 1-ethyl-1-methylpiperidinium bromide to deionized water, then add D-fructose-1,6-diphosphate dicalcium salt, stir at 100°C for 3 hours, then add 0.5 mol / L sodium hydroxide solution, continue stirring for 3 hours, remove water under reduced pressure, add anhydrous ethanol to dissolve, filter, remove ethanol from the filtrate under reduced pressure, and obtain D-fructose-1,6-diphosphate dicalcium salt ionic liquid;

[0049] c. Grind the vermiculite into 200 mesh powder, immerse it in a 2mol / L nitric acid solution for 3h, then filter it, wash it with water until the filtrate is neutral, dry it to obtain acidified vermiculite powder, add the acidified vermiculite powder to deionized water, stir it to form a 10% acidified vermiculite suspension by mass, dissolve D-fructose-1,6-diphosphate dicalcium salt ionic liquid in deionized water to obtain a 12% ionic liquid solution by mass, add the ionic liquid solution dropwise to the acidified vermiculite suspension, perform ultrasonic assisted dispersion while adding dropwise, react at 80°C for 3h, filter out the precipitate, dry it, and grind it into 200 mesh powder to obtain intercalated modified vermiculite powder;

[0050] d. Add water to corn starch to prepare starch milk, heat to 80°C, add intercalated modified vermiculite powder and stir continuously to obtain starch paste, then spray the starch paste evenly on the surface of fertilizer particles through a nozzle, dry at 60°C for 60 minutes, spray the composite microbial liquid evenly on the surface of the coated and dried fertilizer particles through a spray device, and dry at 40°C for 5 hours to obtain the microbial coated fertilizer.

[0051] The composite microbial bacterial liquid is prepared by mixing Paecilomyces lilacinus, Sphingomonas oligophenolica, Bacillus megaterium, Paenibacillus gelatinosa, Bacillus licheniformis, Bacillus megaterium and Bacillus pumilus in a ratio of 1:1:2:1:3:2:2, and is inoculated, activated, fermented and diluted to obtain a total colony count of ≥5×10 9 CFU / mL.

[0052] The organic fertilizer raw materials include the following components in parts by weight: 40 parts of livestock and poultry manure, 10 parts of corn straw, 10 parts of wheat straw, 10 parts of urea, 3 parts of diammonium phosphate, 5 parts of potassium sulfate and 5 parts of potassium humate.

[0053] In the step b, the mass ratio of pyridinium cationic bromide, deionized water, D-fructose-1,6-diphosphate dicalcium salt and sodium hydroxide solution is 1:30:1:2.

[0054] In the step c, the mass ratio of the ionic liquid solution to the acidified vermiculite suspension is 1:2; and in the step d, the mass ratio of corn starch, water and intercalated modified vermiculite powder is 5:30:1.

[0055] The chelating agent is diethylenetriaminepentaacetic acid, and the surfactant is sodium dodecylbenzenesulfonate.

[0056] The eluent comprises the following components in parts by weight: 1 part of a chelating agent, 1 part of a surfactant, and 80 parts of deionized water.

[0057] Example 2

[0058] A composite soil conditioner comprises the following components in parts by weight: 10 parts of fly ash, 5 parts of carbide slag, 30 parts of water and 30 parts of microbial coated fertilizer.

[0059] The composite soil conditioner is prepared by the following steps:

[0060] S1. The chelating agent and the surfactant are dissolved in 80 parts of deionized water to obtain an eluent, and then fly ash is added to the eluent, stirred for 2 hours, filtered, and the fly ash after elution is mixed with water to obtain a fly ash suspension, and then the fly ash suspension is activated by microwave treatment (power 500W, treatment time 10min), ultrasonic treatment (frequency 20kHz, treatment time 15min) and ultraviolet laser treatment (power 5W, treatment time 5min) to obtain an activated fly ash suspension;

[0061] S2. Mix the activated fly ash suspension with carbide slag and microbial coated fertilizer, stir evenly, and obtain the composite soil conditioner.

[0062] The bio-coated fertilizer is prepared by the following steps:

[0063] a. The livestock and poultry manure, corn stalks and wheat stalks were mixed and composted, and fermented for 30 days, to which urea, diammonium phosphate, potassium sulfate and potassium humate were added, and mixed to obtain an organic fertilizer raw material;

[0064] b. Add 1-butyl-1-methylpiperidinium bromide to deionized water, then add D-fructose-1,6-diphosphate dicalcium salt, stir at 80°C for 1 hour, then add 0.5 mol / L sodium hydroxide solution, continue stirring for 2 hours, remove water under reduced pressure, add anhydrous ethanol to dissolve, filter, remove ethanol from the filtrate under reduced pressure, and obtain D-fructose-1,6-diphosphate dicalcium salt ionic liquid;

[0065] c. Grind the vermiculite into 200 mesh powder, immerse it in a 2mol / L nitric acid solution for 1h, then filter it, wash it with water until the filtrate is neutral, and dry it to obtain acidified vermiculite powder. Then add the acidified vermiculite powder to deionized water, stir it evenly to form a 5% acidified vermiculite suspension by mass, dissolve D-fructose-1,6-diphosphate dicalcium salt ionic liquid in deionized water to obtain an 8% ionic liquid solution by mass, and drop the ionic liquid solution into the acidified vermiculite suspension. While dropping, perform ultrasonic-assisted dispersion. After reacting at 80°C for 3h, filter out the precipitate, dry it, and grind it into 200 mesh powder to obtain intercalated modified vermiculite powder;

[0066] d. Add water to corn starch to prepare starch milk, heat to 70°C, add intercalated modified vermiculite powder and stir continuously to obtain starch paste, then spray the starch paste evenly on the surface of fertilizer particles through a nozzle, dry at 50°C for 30 minutes, spray the composite microbial liquid evenly on the surface of the coated and dried fertilizer particles through a spray device, and dry at 30°C for 2 hours to obtain the microbial coated fertilizer.

[0067] The composite microbial bacterial liquid is prepared by mixing Paecilomyces lilacinus, Sphingomonas oligophenolica, Bacillus megaterium, Paenibacillus gelatinosa, Bacillus licheniformis, Bacillus megaterium and Bacillus pumilus in a ratio of 1:1:2:1:3:2:2, and is inoculated, activated, fermented and diluted to obtain a total colony count of ≥5×10 9 CFU / mL.

[0068] The organic fertilizer raw materials include the following components in parts by weight: 60 parts of livestock and poultry manure, 20 parts of corn straw, 20 parts of wheat straw, 20 parts of urea, 10 parts of diammonium phosphate, 12 parts of potassium sulfate and 10 parts of potassium humate.

[0069] In the step b, the mass ratio of pyridinium cationic bromide, deionized water, D-fructose-1,6-diphosphate dicalcium salt and sodium hydroxide solution is 1:40:2:5.

[0070] In the step c, the mass ratio of the ionic liquid solution to the acidified vermiculite suspension is 1:3; and in the step d, the mass ratio of corn starch, water and intercalated modified vermiculite powder is 5:50:2.

[0071] The chelating agent is ethylenediaminetetraacetic acid, and the surfactant is nonylphenol polyoxyethylene ether.

[0072] The eluent comprises the following components in parts by weight: 3 parts of a chelating agent, 3 parts of a surfactant, and 100 parts of deionized water.

[0073] Example 3

[0074] A composite soil conditioner comprises the following components in parts by weight: 20 parts of fly ash, 10 parts of carbide slag, 40 parts of water and 40 parts of microbial coated fertilizer.

[0075] The composite soil conditioner is prepared by the following steps:

[0076] S1. The chelating agent and the surfactant are dissolved in deionized water to obtain an eluent, and then fly ash is added to the eluent, stirred for 3 hours, filtered, and the eluent fly ash is mixed with water to obtain a fly ash suspension, and then the fly ash suspension is activated by microwave treatment (power 650W, treatment time 12min), ultrasonic treatment (frequency 30kHz, treatment time 18min) and ultraviolet laser treatment (power 7W, treatment time 7min) to obtain an activated fly ash suspension;

[0077] S2. Mix the activated fly ash suspension with carbide slag and microbial coated fertilizer, stir evenly, and obtain the composite soil conditioner.

[0078] The microbial coated fertilizer is prepared by the following steps:

[0079] a. The livestock and poultry manure, corn straw and wheat straw were mixed and composted, and fermented for 35 days, to which urea, diammonium phosphate, potassium sulfate and potassium humate were added, and mixed to obtain an organic fertilizer raw material;

[0080] b. Add 1-propyl-1-methylpiperidinium bromide to deionized water, then add D-fructose-1,6-diphosphate dicalcium salt, stir at 90°C for 2h, then add 0.5mol / L sodium hydroxide solution, continue stirring for 2.5h, remove water under reduced pressure, add anhydrous ethanol to dissolve, filter, remove ethanol from the filtrate under reduced pressure to obtain D-fructose-1,6-diphosphate dicalcium salt ionic liquid;

[0081] c. Grind the vermiculite into 200 mesh powder, immerse it in a 2mol / L nitric acid solution for 2h, then filter it, wash it with water until the filtrate is neutral, and dry it to obtain acidified vermiculite powder, then add the acidified vermiculite powder to deionized water, stir it evenly to form an acidified vermiculite suspension with a mass fraction of 7%, dissolve D-fructose-1,6-diphosphate dicalcium salt ionic liquid in deionized water to obtain an ionic liquid solution with a mass fraction of 10%, and drop the ionic liquid solution into the acidified vermiculite suspension, while performing ultrasonic assisted dispersion, react at 80°C for 3h, filter out the precipitate, dry it, and grind it into 200 mesh powder to obtain intercalated modified vermiculite powder;

[0082] d. Add water to corn starch to prepare starch milk, heat to 75°C, add intercalated modified vermiculite powder and stir continuously to obtain starch paste, then spray the starch paste evenly on the surface of fertilizer particles through a nozzle, dry at 55°C for 45 minutes, spray the composite microbial liquid evenly on the surface of the coated and dried fertilizer particles through a spray device, and dry at 35°C for 3 hours to obtain the microbial coated fertilizer.

[0083] The composite microbial bacterial liquid is prepared by mixing Paecilomyces lilacinus, Sphingomonas oligophenolica, Bacillus megaterium, Paenibacillus gelatinosa, Bacillus licheniformis, Bacillus megaterium and Bacillus pumilus in a ratio of 1:1:2:1:3:2:2, and is inoculated, activated, fermented and diluted to obtain a total colony count of ≥5×10 9 CFU / mL.

[0084] The organic fertilizer raw materials include the following components in parts by weight: 50 parts of livestock and poultry manure, 15 parts of corn straw, 15 parts of wheat straw, 15 parts of urea, 7 parts of diammonium phosphate, 8 parts of potassium sulfate and 8 parts of potassium humate.

[0085] In the step b, the mass ratio of pyridinium cationic bromide, deionized water, D-fructose-1,6-diphosphate dicalcium salt and sodium hydroxide solution is 1:35:1.5:3.

[0086] In the step c, the mass ratio of the ionic liquid solution to the acidified vermiculite suspension is 1:2.5; and in the step d, the mass ratio of corn starch, water and intercalated modified vermiculite powder is 5:40:1.5.

[0087] The chelating agent is aminotrimethylenephosphonic acid, and the surfactant is dodecylphenol polyoxyethylene ether.

[0088] The eluent comprises the following components in parts by weight: 2 parts of a chelating agent, 2 parts of a surfactant, and 90 parts of deionized water.

[0089] Comparative Example 1

[0090] The difference between this comparative example and Example 3 is that the fly ash is directly prepared into a fly ash suspension without being activated, and the rest is the same as Example 3.

[0091] Comparative Example 2

[0092] The difference between this comparative example and Example 3 is that D-fructose-1,6-diphosphate dicalcium salt ionic liquid is not added in the preparation of the microbial coated fertilizer, and the rest is the same as Example 3.

[0093] Test Example 1

[0094] Soil physical and chemical properties testing

[0095] A sample plot of 24m long and 15m wide was selected in the experimental area. The land was divided into 6 groups, each group was made into 3 parallel groups, and a total of 18 plots were formed. Each plot was 5m long and 4m wide.

[0096] The soil conditioner prepared in each embodiment of the present invention and the comparative example is evenly spread on the surface of the soil to be conditioned, and then the soil is tilled with a rotary tiller to fully mix the soil and the soil conditioner. The tillage depth is 30 cm, and the amount of the soil conditioner is 30% of the mass of the 30 cm soil. Then the field surface is tidied and irrigated. The irrigation water volume is 60-80 m3 per mu. 3 ,Soil samples were taken on the 14th day to test various physical and chemical properties of the soil. The results are shown in Table 1.,The control group did not use any conditioners and fertilizers, and included rotary tillage and irrigation steps.

[0097] Table 1 Test results of soil physical and chemical properties

[0098] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Control group proportion 2.5133 2.5218 2.5322 2.3207 2.2518 2.0128 Porosity / % 68.58 71.22 71.48 54.68 55.77 32.15 Salt content / % 0.1356 0.1335 0.1328 0.1835 0.1762 0.2523 Alkalinity / % 6.45 6.28 6.34 8.65 8.92 12.25 pH 7.42 7.38 7.45 7.95 8.12 8.77 Hardening No hardening No hardening No hardening No hardening Slightly hardened Obvious hardening Water content / % 62.17 64.23 67.42 48.25 42.22 32.17

[0099] Reasonable soil density is beneficial to soil stability and fertilizer and water retention capacity. Higher density means that the compactness between soil particles is increased, which can better maintain soil fertility and moisture, and provide a good foundation for plant growth. As can be seen from the above table, Examples 1-3 of the present invention increase soil density and are relatively stable; porosity reflects the size and number of pores in the soil. Good porosity is beneficial to soil ventilation and water exchange, and promotes the respiration and growth of plant roots. Examples 1-3 increase soil porosity by adding microbial coated fertilizer and activating fly ash. The microbial coated fertilizer forms a large number of pore structures in the soil, which is conducive to soil ventilation and water penetration; Examples 1-3 remove fly ash by eluting fly ash with chelating agents and surfactants. Surface salt, carbide slag further solidifies the residual heavy metal ions and reduces the release of salt. The microbial coated fertilizer also helps to improve the salt balance of the soil. Therefore, the present invention can reduce the soil salt content at a glance, which is beneficial to improving the ecological environment of the soil and reducing the inhibitory effect of salt on plant growth; excessive alkalinity will affect the plant's absorption of nutrients and reduce the fertility of the soil. The conditioners of Examples 1-3 reduce the alkalinity and pH value of the soil; the activation treatment of the microbial coated fertilizer and fly ash in Examples 1-3 makes the soil particles more tightly bound. Therefore, the conditioner of the present invention reduces the occurrence of soil compaction and is beneficial to soil ventilation and water penetration; the present invention also increases the water content of the soil through the action of the conditioner, thereby improving the water retention capacity of the soil.

[0100] Test Example 2

[0101] Effective viable count detection

[0102] Depend on Figure 1It can be seen that the number of effective live bacteria in the soil was measured on the 7th, 14th and 28th days of the experiment in Example 1. The determination method adopted the plate count method in the "Handbook of Soil Microbiological Analysis Methods". The results are shown in Figure 1 .

[0103] Depend on Figure 1 It can be seen that Figure 2 It can be seen that the effective viable counts of Examples 1-3 on the 7th, 14th and 28th days were all higher than those of Comparative Examples 1 and 2 and the control group, and still had a high effective viable count after 28 days, which indicates that the microbial coated fertilizer can continue to play a role. The activity of microorganisms helps to transform and decompose soil nutrients and improve soil fertility, indicating that the microbial coated fertilizer prepared by the present invention provides a suitable living environment for microorganisms, promotes the growth and reproduction of microorganisms, and these microorganisms interact with the soil environment in the soil to establish a stable ecosystem, enhance the ecological function of the soil, and provide continuous support for plant growth.

[0104] Test Example 3

[0105] Heavy metal content detection

[0106] On the 14th day of Example 1, the heavy metal content in the soil was detected using the method GB / T17141-1997 "Soil quality lead and cadmium determination graphite furnace atomic absorption spectrophotometry", the results are shown in Figure 2 .

[0107] Depend on Figure 2 As a result, the conditioner of the present invention effectively reduces the heavy metal content in the soil. This is because the present invention activates the fly ash suspension by microwave, ultrasound and ultraviolet laser treatment, so that the conditioner effectively changes the soil structure. In this process, the soil aggregate content is improved, the air permeability and water permeability of the soil are enhanced, and as the soil structure changes, the gaps between soil particles become larger, providing channels for heavy metal ions, enabling them to migrate in the soil. At the same time, microbial coated fertilizer also plays a role, which combines with heavy metal ions and further promotes the movement of heavy metal ions to the deep soil layer. The present invention activates the fly ash suspension by microwave, ultrasound and ultraviolet laser treatment, which promotes the migration of heavy metal ions in the soil and allows heavy metals to penetrate deep into the soil. At the same time, the addition of carbide slag further solidifies the residual heavy metal ions. Microbial coated fertilizer also plays a role, which combines with heavy metals to reduce the bioavailability and mobility of heavy metals.

[0108] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0109] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A composite soil conditioner, characterized in that: The invention comprises the following components in parts by weight: 10-30 parts of fly ash, 5-15 parts of carbide slag, 30-50 parts of water, and 30-50 parts of microbial coated fertilizer; The composite soil conditioner is prepared by the following steps: S1. dissolving a chelating agent and a surfactant in deionized water to obtain an eluent, then adding fly ash to the eluent, stirring for 2-4 hours, filtering, adding water to the eluent fly ash to obtain a fly ash suspension, and then subjecting the fly ash suspension to microwave treatment, ultrasonic treatment and ultraviolet laser treatment to activate the fly ash suspension to obtain an activated fly ash suspension; S2. The activated fly ash suspension is mixed with carbide slag and microbial coated fertilizer, and stirred evenly to obtain the composite soil conditioner; The microbial coated fertilizer is prepared by the following steps: a. The livestock and poultry manure, corn straw and wheat straw are mixed and composted, and fermented for 30-40 days, to which urea, diammonium phosphate, potassium sulfate and potassium humate are added, and mixed to obtain an organic fertilizer raw material; b. Add pyridinium cationic bromide to deionized water, then add D-fructose-1,6-dicalcium diphosphate, stir at 80-100°C for 1-3h, then add 0.5mol / L sodium hydroxide solution, continue stirring for 2-3h, remove water under reduced pressure, add anhydrous ethanol to dissolve, filter, remove ethanol from the filtrate under reduced pressure, and obtain D-fructose-1,6-dicalcium diphosphate ionic liquid; c. Grind the vermiculite into 200 mesh powder, immerse it in a 2mol / L nitric acid solution for 1-3h, then filter it, wash it with water until the filtrate is neutral, and dry it to obtain acidified vermiculite powder. Then add the acidified vermiculite powder to deionized water, stir it evenly to form an acidified vermiculite suspension with a mass fraction of 5%-10%, dissolve D-fructose-1,6-dicalcium diphosphate ionic liquid in deionized water to obtain an ionic liquid solution with a mass fraction of 8%-12%, and drop the ionic liquid solution into the acidified vermiculite suspension. While dropping, perform ultrasonic-assisted dispersion. After reacting at 80°C for 3h, filter out the precipitate, dry it, and grind it into 200 mesh powder to obtain intercalated modified vermiculite powder; d. Add water to corn starch to prepare starch milk, heat to 70-80°C, add intercalated modified vermiculite powder and stir continuously to obtain starch paste, then spray the starch paste evenly on the surface of fertilizer particles through a nozzle, dry at 50-60°C for 30-60min, spray the composite microbial liquid evenly on the surface of the coated and dried fertilizer particles through a spray device, dry at 30-40°C for 2-5h, and obtain the microbial coated fertilizer.

2. A composite soil conditioner according to claim 1, characterized in that: The pyridinium type cationic bromide salt is one of 1-ethyl-1-methylpiperidinium bromide salt, 1-propyl-1-methylpiperidinium bromide salt and 1-butyl-1-methylpiperidinium bromide salt.

3. A composite soil conditioner according to claim 2, characterized in that: The composite microbial bacterial liquid is prepared by mixing Paecilomyces lilacinus, Sphingomonas oligophenolica, Bacillus megaterium, Paenibacillus gelatinosa, Bacillus licheniformis, Bacillus megaterium and Bacillus pumilus in a ratio of 1:1:2:1:3:2:2, and is inoculated, activated, fermented and diluted to obtain a total colony count of ≥5×10 9 CFU / mL.

4. The composite soil conditioner according to claim 3, characterized in that: The organic fertilizer raw materials include the following components in parts by weight: 40-60 parts of livestock and poultry manure, 10-20 parts of corn straw, 10-20 parts of wheat straw, 10-20 parts of urea, 3-10 parts of diammonium phosphate, 5-12 parts of potassium sulfate and 5-10 parts of potassium humate.

5. The composite soil conditioner according to claim 4, characterized in that: In the step b, the mass ratio of pyridinium cationic bromide, deionized water, D-fructose-1,6-diphosphate dicalcium salt and sodium hydroxide solution is 1:30-40:1-2:2-5.

6. The composite soil conditioner according to claim 5, characterized in that: In the step c, the mass ratio of the ionic liquid solution to the acidified vermiculite suspension is 1:2-3; and in the step d, the mass ratio of corn starch, water and intercalated modified vermiculite powder is 5:30-50:1-2.

7. The composite soil conditioner according to claim 6, characterized in that: The chelating agent is one of ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and aminotrimethylenephosphonic acid, and the surfactant is one of nonylphenol polyoxyethylene ether, sodium dodecylbenzene sulfonate, sodium dodecyl alcohol ether sulfate and dodecylphenol polyoxyethylene ether.

8. The composite soil conditioner according to claim 7, characterized in that: The eluent comprises the following components in parts by weight: 1-3 parts of a chelating agent, 1-3 parts of a surfactant, and 80-100 parts of deionized water.

9. The composite soil conditioner according to claim 8, characterized in that: The power of the microwave treatment is 500-800W, and the treatment time is 10-15min; the frequency of the ultrasonic treatment is 20-40kHz, and the treatment time is 15-20min; the power of the ultraviolet laser treatment is 5-10W, and the treatment time is 5-10min.

10. Use of the composite soil conditioner according to any one of claims 1 to 9 in improving saline-alkali land.

Images