Efficient and environment-friendly saline-alkali soil improver and preparation device and preparation method thereof

Abstract

The invention belongs to the technical field of saline-alkali soil improvement, and particularly relates to an efficient and environment-friendly saline-alkali soil improver and a preparation device and a preparation method thereof. The method comprises the following steps: S1, respectively culturing a plurality of microbial agents in a culture medium, and mixing the microbial agents after the culture period is ended to obtain a compound microbial agent; s2, dissolving sodium carboxymethyl cellulose in distilled water for modification treatment to obtain a modified sodium carboxymethyl cellulose solution; s3, mixing the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan to obtain a coating solution; s4, mixing a compound microbial agent, a glucose solution, biochar and the coating liquid, stirring and dispersing, and drying to obtain a compound biological agent; and S5, uniformly mixing the bottom mud, titanium gypsum, the composite biological agent, amino acid, ground phosphate rock and an iron fertilizer to obtain the saline-alkali soil modifier.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land improvement, and specifically relates to a highly efficient and environmentally friendly saline-alkali land improver and a preparation device and a preparation method thereof. Background Art

[0002] In recent years, the use of microbial agents with specific functions for biological improvement has become a research focus in the field of saline-alkali land improvement. Biological improvement has the advantages of being environmentally friendly and sustainable. It improves the structure and function of soil microbial communities, promotes soil nutrient circulation, and improves soil fertility, ultimately achieving the purpose of improving saline-alkali land. However, how to improve the survival rate and effectiveness of microbial agents in practical applications, as well as their synergy with other improvement measures, remains a key issue that needs to be addressed. Summary of the invention

[0003] The present invention overcomes the deficiencies of the prior art and provides a highly efficient and environmentally friendly saline-alkali land improver and a preparation device and method thereof.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for preparing an efficient and environmentally friendly saline-alkali land improver comprises the following steps:

[0006] S1, placing several kinds of microbial agents in culture medium for cultivation respectively, and mixing them after the cultivation period to obtain a composite microbial agent;

[0007] S2, dissolving sodium carboxymethyl cellulose in distilled water for modification to obtain a modified sodium carboxymethyl cellulose solution;

[0008] S3, mixing the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan to obtain a coating solution;

[0009] S4, mixing the composite microbial agent, glucose solution, biochar and coating liquid, stirring and dispersing, and then drying to obtain a composite biological agent;

[0010] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer to obtain a saline-alkali land conditioner.

[0011] In a preferred embodiment of the present invention, the microbial agent in step S1 includes one or more of alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria.

[0012] In a preferred embodiment of the present invention, the preparation method of the modified sodium carboxymethyl cellulose solution in step S2 is: after dissolving sodium carboxymethyl cellulose in distilled water, nitrogen is introduced to exhaust the air, the temperature is raised to 65-75° C., potassium persulfate is added, and stirring is performed for 20-40 minutes; γ-aminobutyric acid and magnesium sulfate are added in sequence, and the mixture is stirred and heated at a temperature of 65-75° C. for 2-4 hours; the mixture is cooled to 20-26° C. and allowed to stand for 40-60 minutes to obtain the modified sodium carboxymethyl cellulose solution.

[0013] In a preferred embodiment of the present invention, the preparation method of the coating liquid in step S3 is: after mixing modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan, heating the mixed solution to 50-60°C and stirring; after all the components are completely dissolved, adding glycerol to adjust the viscosity and moisture retention of the coating liquid, adding a calcium chloride solution with a mass fraction of 1%-3% to adjust the strength and stability of the coating liquid; wherein the viscosity of the modified sodium carboxymethyl cellulose solution is between 10-50mPa.s; the mass proportions of the modified sodium carboxymethyl cellulose solution, sodium alginate, chitosan, glycerol and calcium chloride solution in the coating liquid are: 40-80%, 12-25%, 12-25%, 3-8% and 3-8%, respectively.

[0014] In a preferred embodiment of the present invention, the biochar preparation method in step S4 is hydrothermal carbonization or biomass boiler combustion.

[0015] In a preferred embodiment of the present invention, in step S4, the mass proportions of the composite microbial agent, glucose solution, biochar and coating liquid are 20-40%, 5-15%, 20-40% and 20-40% respectively; the drying method of the mixture is one of spray drying, vacuum drying and freeze drying.

[0016] In a preferred embodiment of the present invention, the mass proportions of the sludge, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer in step S5 are 25-40%, 35-50%, 15-25%, 5-10%, 6-12% and 6-12%, respectively.

[0017] An efficient and environmentally friendly saline-alkali land improver preparation device, based on the above preparation method, comprises a first mixing drum, a vacuum drying oven and a second mixing drum;

[0018] The first mixing cylinder comprises a first cylinder, a first feed port arranged at the top of the first cylinder, a first discharge port arranged at the bottom of the first cylinder, a first stirring assembly arranged inside the first cylinder, and a temperature control assembly arranged inside the first cylinder;

[0019] The vacuum drying oven comprises a body, a vacuum chamber installed in the upper part of the body, and a vacuum pumping assembly installed in the lower part of the body;

[0020] The second mixing barrel comprises a second barrel, a second material inlet arranged at the top of the second barrel, a second material outlet arranged at the bottom of the second barrel, and a second stirring assembly arranged in the second barrel.

[0021] In a preferred embodiment of the present invention, the temperature control component includes a medium tube; the medium tube is spirally wound around the axis of the first mixing cylinder and abuts against the inner wall of the first mixing cylinder; the head end and the tail end of the medium tube extend outward through the inner wall of the first mixing cylinder to form a medium inlet and a medium outlet respectively.

[0022] A highly efficient and environmentally friendly saline-alkali land improver is prepared by the above-mentioned highly efficient and environmentally friendly saline-alkali land improver preparation method.

[0023] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0024] (1) The present invention provides a highly efficient and environmentally friendly saline-alkali land improver and a preparation method and a preparation device thereof, aiming to improve the efficiency of saline-alkali land improvement, promote saline-alkali land vegetation restoration, and ultimately realize the resource utilization of saline-alkali land.

[0025] (2) The preparation method provided by the present invention uses a combination of composite microbial agents, biochar, sediment, titanium gypsum, amino acids, phosphate rock powder and iron fertilizer, and prepares a coating liquid to protect the microbial agents. The multiple strains in the composite microbial agent work synergistically to improve the soil microbial environment; biochar provides good soil structure and nutrients; sediment and titanium gypsum improve the physical and chemical properties of the soil; amino acids, phosphate rock powder and iron fertilizer supplement nutrients. Compared with the single improver protection mechanism in the prior art, the improver of the present invention significantly increases the growth rate of plants in saline-alkali land.

[0026] (3) The preparation method provided by the present invention uses modified sodium carboxymethyl cellulose, sodium alginate and chitosan to prepare a coating liquid to coat the composite microbial agent. The coating liquid can protect the microbial agent from damage by the external environment and improve its survival rate; glycerol improves the moisture retention of the coating liquid; calcium chloride improves the strength and stability of the coating liquid; and the controlled release mechanism prolongs the activity time of the microorganism. Compared with the protection measures for microbial agents in the prior art, the survival rate and activity of the composite microbial agent in the improver of the present invention are significantly improved, and the improvement effect is better.

[0027] (4) The present invention combines a variety of improvers with coated microbial agent technology. The composite improver formula provides nutrition and a good growth environment for microorganisms, while the coating technology ensures that the microbial agent survives and functions in the soil for a long time, achieving a significant improvement in the improvement effect. In addition, the composite improver quickly improves the physical and chemical properties of the soil and provides nutrients, while the coated microbial agent continuously improves the soil environment and increases soil fertility, ultimately producing a more significant and lasting improvement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a flow chart of a method for preparing a highly efficient and environmentally friendly saline-alkali land improver;

[0030] Figure 2 It is a structural schematic diagram of a highly efficient and environmentally friendly saline-alkali land improver preparation device;

[0031] Figure 3 is a schematic structural diagram of a first mixing cylinder;

[0032] Figure 4 It is a schematic diagram of the structure of a vacuum drying oven;

[0033] Figure 5 is a schematic structural diagram of a second mixing cylinder;

[0034] In the figure: 1. first mixing cylinder; 2. vacuum drying oven; 3. second mixing cylinder; 11. first cylinder body; 12. first feed inlet; 13. first discharge outlet; 14. first stirring assembly; 15. temperature control assembly; 16. jacket; 17. ventilation assembly; 18. sampling valve; 19. window; 21. machine body; 22. vacuum chamber; 23. vacuum pumping assembly; 31. second cylinder body; 32. second feed inlet; 33. second discharge outlet; 34. second stirring assembly; 141. stirring shaft; 142. stirring paddle; 143. positioning seat; 144. first power unit; 151. medium pipe; 152. medium inlet; 153. medium outlet; 161. liquid inlet; 162 liquid outlet; 171. mounting bracket; 172. ventilation pipe; 1431. bracket; 1432. shaft seat. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0039] Application Overview

[0040] Salt-alkali land conditioners are a type of additives used to improve soil properties. They are divided into natural conditioners, synthetic conditioners, biological conditioners and composite conditioners. Natural conditioners use inorganic and organic materials inherent in the world, synthetic conditioners include high molecular polymers, and biological conditioners are based on the symbiotic relationship between microorganisms and plants. These conditioners play an important role in improving soil quality and promoting agricultural production, but they also have certain limitations. For example, biological conditioners may be restricted by the soil environment, and synthetic materials may face degradation problems. Therefore, researching and developing soil improvement programs suitable for the resources and farming characteristics of specific regions is of great significance for improving degraded soils and increasing cultivated land areas.

[0041] The present application provides a highly efficient and environmentally friendly saline-alkali soil conditioner suitable for carbonate saline-alkali soils. This type of soil usually has a high pH value and contains more carbonates and bicarbonates.

[0042] The titanium gypsum in the present application is an industrial by-product, the main component of which is calcium sulfate, which has the ability to neutralize the alkalinity of the soil and reduce the pH value of the soil by reacting with alkaline substances in the soil; microbial preparations can promote the decomposition and circulation of organic matter in the soil, improve the biological activity and fertility of the soil, and reduce the alkalinity of the soil; amino acids are essential nutrients for plant growth, which can be directly absorbed and utilized by plants to promote plant growth, and at the same time form chelates with multivalent metal ions in the soil to improve the soil's aggregate structure; bottom mud is soil that has undergone physical and chemical actions and biological reactions and is deposited in slow-flowing or stagnant water, which can improve the physical and chemical properties of the soil and increase soil fertility and aggregation.

[0043] Biochar in this application is a mesoporous material, and the production process includes hydrothermal carbonization, pyrolysis, gasification and biomass boiler combustion. Among them, hydrothermal carbonization is a thermochemical process in the temperature range of 180-375°C, in which the biomass is in a subcritical or supercritical water environment, and automatically generates pressure (2-6MPa) in a closed system, realizing the conversion of high-moisture biomass into hydrothermal charcoal in a short time (ranging from a few minutes to a few hours); pyrolysis refers to the process of preparing biochar from biomass raw materials at a temperature of 300-1200°C in an oxygen-free or oxygen-limited atmosphere; gasification is a thermochemical process for preparing biochar at a higher temperature (>500°C) and under anoxic conditions; biomass boiler combustion refers to the combustion reactor mainly through the heating of biomass under aerobic conditions, and the generated gas is burned near the biomass. Since the combustion technology usually does not lead to complete combustion, biochar can be obtained from it.

[0044] The spray drying method mentioned in this application is a drying technology that atomizes liquid materials into tiny droplets and contacts them with hot air to quickly evaporate water. The advantage of this method is that the drying speed is fast, usually only a few seconds, and the solution and emulsion can be directly dried into powder or granular products. In addition, during the spray drying process, the temperature of the droplets is relatively low, which can reduce the denaturation and loss of heat-sensitive materials. The vacuum drying method is a drying method carried out under reduced pressure. By reducing the pressure, moisture can be removed at a lower temperature, reducing oxidation and thermal damage of the material and maintaining its original properties. The freeze drying method is to freeze the water-containing material into a solid first, and then directly sublimate the water into steam under low temperature and low pressure conditions to achieve the purpose of drying.

[0045] The exemplary culture conditions of various bacterial agents in the present invention are as follows:

[0046] Alkali-resistant Bacillus uses beef extract peptone medium (NA) as a culture medium, is cultured at 30°C for 24-36 hours, and the pH is controlled at about 8.

[0047] The culture medium formula of Bacillus licheniformis is 2g / L α-lactose, 20g / L soybean meal, 1g / L MnSO4, 0.01g / L FeSO4, 0.04g / L MgSO4, 2g / L K2HPO4, and the culture conditions are 4% inoculation, 24-48h culture, and initial pH 7. The maximum number of viable bacteria in a 50L fermenter is 1.36×10^9CFU / mL.

[0048] Bacillus subtilis uses beef extract peptone medium (NA) as the culture medium with a pH range of 4.8-9.0. During the culture process, the pH value shows a trend of first decreasing and then increasing. The culture temperature is 30°C in the early stage and increased to 36°C in the later stage for 24-48 hours.

[0049] The nitrogen-fixing bacteria use Yersinia medium as the culture medium, and the pH is controlled at 8-10. According to the detection of nitrogen fixation activity, the culture period is 24-36 hours.

[0050] Trichoderma grows on potato culture medium (PDA), which is composed of potatoes, glucose and agar, with a pH of 1.5 and a culture period of 3-7 days.

[0051] The culture medium for halotolerant actinomycetes is based on ISP-1, with 1-2% concentration of NaCl solution added, pH ranging from 6 to 8, culture temperature of 25-37°C, and culture for 24-48h.

[0052] Lactic acid bacteria were grown on MRS medium. Buffer was added at 2.5 hours of fermentation to adjust the pH to 6.6, and then nutritional factors (whey: tomato juice: carrot juice: milk = 4:6:6:5) of the original fermentation liquid were added and fermented for 4 hours.

[0053] Exemplary Methods

[0054] like Figure 1 As shown, a method for preparing an efficient and environmentally friendly saline-alkali land improver comprises the following steps:

[0055] S1, placing several kinds of microbial agents in culture medium for cultivation respectively, and mixing them after the cultivation period to obtain a composite microbial agent;

[0056] S2, dissolving sodium carboxymethyl cellulose in distilled water for modification to obtain a modified sodium carboxymethyl cellulose solution;

[0057] S3, mixing the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan to obtain a coating solution;

[0058] S4, mixing the composite microbial agent, glucose solution, biochar and coating liquid, stirring and dispersing, and then drying to obtain a composite biological agent;

[0059] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer to obtain a saline-alkali land conditioner.

[0060] Below, each step will be described in detail.

[0061] The microbial agent in step S1 includes one or more of alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria.

[0062] The preparation method of the modified sodium carboxymethyl cellulose solution in step S2 is as follows: after dissolving sodium carboxymethyl cellulose in distilled water, nitrogen is introduced to exhaust the air, the temperature is raised to 65-75° C., potassium persulfate is added, and stirring is performed for 20-40 minutes; γ-aminobutyric acid and magnesium sulfate are added in sequence, and the mixture is stirred and heated at a temperature of 65-75° C. for 2-4 hours; the mixture is cooled to 20-26° C., and allowed to stand for 40-60 minutes to obtain the modified sodium carboxymethyl cellulose solution.

[0063] The preparation method of the coating liquid in step S3 is: after mixing modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan, heating the mixed solution to 50-60°C and stirring; after all the components are completely dissolved, adding glycerol with a mass fraction of 1%-3% to adjust the viscosity and moisture retention of the coating liquid, adding calcium chloride solution with a mass fraction of 1%-3% to adjust the strength and stability of the coating liquid; wherein the viscosity of the modified sodium carboxymethyl cellulose solution is between 10-50mPa.s; the mass proportions of the modified sodium carboxymethyl cellulose solution, sodium alginate, chitosan, glycerol and calcium chloride solution in the coating liquid are: 40-80%, 12-25%, 12-25%, 3-8% and 3-8%, respectively.

[0064] The biochar preparation method in step S4 is hydrothermal carbonization or biomass boiler combustion.

[0065] In step S4, the mass proportions of the composite microbial agent, glucose solution, biochar and coating liquid are 20-40%, 5-15%, 20-40% and 20-40% respectively; the drying method of the mixture is one of spray drying, vacuum drying and freeze drying.

[0066] In step S5, the mass proportions of sludge, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer are 25-40%, 35-50%, 15-25%, 5-10%, 6-12% and 6-12%, respectively.

[0067] Exemplary Devices

[0068] like Figure 2As shown, a highly efficient and environmentally friendly saline-alkali land improver preparation device includes a first mixing drum 1, a vacuum drying oven 2 and a second mixing drum 3. The raw materials are mixed in the first mixing drum 1, then dried in the vacuum drying oven 2, and finally further processed in the second mixing drum 3.

[0069] The first mixing drum 1 comprises a first barrel 11, a first feed port 12 disposed at the top of the first barrel 11, a first discharge port 13 disposed at the bottom of the first barrel 11, a first stirring assembly 14 disposed inside the first barrel 11, and a temperature control assembly 15 disposed inside the first barrel 11;

[0070] The vacuum drying box 2 includes a body 21, a vacuum chamber 22 installed at the upper part of the body 21, and a vacuum pumping assembly 23 installed at the lower part of the body 21;

[0071] The second mixing drum 3 includes a second barrel 31 , a second material inlet 32 ​​arranged at the top of the second barrel 31 , a second material outlet 33 arranged at the bottom of the second barrel 31 , and a second stirring assembly 34 arranged in the second barrel 31 .

[0072] The temperature control assembly 15 includes a medium tube 151; the medium tube 151 is spirally arranged around the axis of the first mixing barrel 1 and abuts against the inner wall of the first mixing barrel 1; the head end and the tail end of the medium tube 151 pass through the inner wall of the first mixing barrel 1 and extend outward to form a medium inlet 152 and a medium outlet 153 respectively. By providing the spiral medium tube 151 and circulating the medium in the medium tube 151, the heat is evenly distributed and the temperature in the first mixing barrel 1 is controlled.

[0073] The first stirring assembly 14 includes a stirring shaft 141 disposed in the first mixing drum 1, a stirring paddle 142 disposed at the bottom of the stirring shaft 141, a positioning seat 143 disposed at the bottom of the first mixing drum 1, and a first power unit 144 disposed at the top of the first mixing drum 1; the positioning seat 143 includes a plurality of brackets 1431 abutting against the inner wall of the first mixing drum 1 and a shaft seat 1432 fixed at the top of the bracket legs 1431; the top end of the stirring shaft 141 is connected to the first power unit 144 for power, and the end is rotatably disposed in the center of the shaft seat 1432. The first power unit 144 provides power for the stirring shaft 141 to rotate, and the rotation of the stirring shaft 141 drives the stirring paddle 142 to rotate, thereby mixing the materials in the first mixing drum 1.

[0074] A hollow jacket 16 is also provided around the first mixing cylinder 1 , and a liquid inlet 161 and a liquid outlet 162 are provided on the jacket 16 . The fluid circulation in the jacket 16 cooperates with the medium pipe 151 to further control the temperature in the first mixing cylinder 1 .

[0075] A ventilation assembly 17 is also provided in the first mixing barrel 1; the ventilation assembly 17 includes a mounting bracket 171 fixed on the inner wall of the first mixing barrel 1 and a ventilation pipe 172 fixed on the mounting bracket 171; one end of the ventilation pipe 172 is close to the bottom of the first mixing barrel 1, and the other end extends outward from the top of the first mixing barrel 1 to connect to an external air source. The first mixing barrel 1 is ventilated through the ventilation pipe 172 to remove air in the mixed liquid.

[0076] A sampling valve 18 for sampling is also provided at the bottom of the first mixing cylinder 1 , and sampling is directly performed through the sampling valve 18 .

[0077] The first mixing cylinder 1 is also provided with a window 19 for observing the inside of the cylinder. By installing the transparent window 19 on the first mixing cylinder 1, the situation inside the cylinder can be directly observed, which is convenient for the operator to monitor and adjust.

[0078] When the device is in use, distilled water and sodium carboxymethyl cellulose are introduced into the first mixing barrel 1 through the first feed port 12, nitrogen is introduced into the sodium carboxymethyl cellulose solution through the vent pipe 172, circulating medium is introduced into the medium pipe 151 through the medium inlet 152, the temperature in the barrel is heated to 65-75°C, potassium persulfate is added through the first feed port 12, the first power unit 144 is started to control the stirring shaft 141 and the stirring paddle 142 to rotate around the axis of the positioning seat 143, and the stirring condition is maintained for 20-40 minutes; after stirring, γ-aminobutyric acid and magnesium sulfate are added in sequence through the first feed port 12, and stirring and heating are continued at a temperature of 65-75°C for 2-4 hours; after stirring, circulating medium is introduced into the medium pipe 151 through the medium inlet 152, the temperature in the barrel is reduced to 20-26°C, and the mixture is allowed to stand for 40-60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0079] Sodium alginate and chitosan are added into the first mixing barrel 1 through the first feed port 12, and the temperature in the barrel is controlled at 50-60°C and stirred; glycerol and calcium chloride solution are continuously added into the stirred solution through the first feed port 12 to obtain a modified sodium carboxymethyl cellulose solution.

[0080] The pre-configured composite microbial agent, biochar and glucose solution are added into the first mixing barrel 1 through the first feed port 12, and mixed evenly to obtain a composite biological agent. The composite biological agent is placed in the vacuum chamber 22 of the vacuum drying oven 2, and the vacuum pumping component 23 is started to dry to obtain a dried composite biological agent.

[0081] The dried composite biological preparation and pre-prepared bottom mud, titanium gypsum, amino acid, phosphate rock powder and iron fertilizer are added into the second mixing drum 3 through the second feed port 31, and the second stirring component 34 of the second mixing drum 3 is started to stir the above materials, and finally collected through the second discharge port 32 to obtain an efficient and environmentally friendly saline-alkali land improver.

[0082] During the whole process, the internal situation of the first mixing barrel 1 is monitored through the viewing window 19, and the mixing conditions are adjusted in time according to the situation in the barrel to ensure the mixing effect. At the same time, sampling and testing are performed through the sampling valve 18 to ensure that the product obtained in each operation is accurate. In addition, through the fluid circulation in the jacket 16 and the medium pipe 151, the temperature in the first mixing barrel 1 is accurately controlled to ensure the mixing effect of the materials.

[0083] The temperature control component of the device includes a medium tube, which is spirally wound around the axis of the first mixing barrel. When in use, a heat transfer medium is introduced into the medium tube to control the temperature in the first mixing barrel through the circulation of the heat transfer medium. The spiral medium tube can evenly distribute heat, avoid local overheating or overcooling, and ensure that the materials are mixed at an appropriate temperature.

[0084] The first stirring assembly of the device includes a stirring shaft arranged in the first mixing drum, a stirring paddle arranged at the bottom of the stirring shaft, a positioning seat arranged at the bottom of the first mixing drum, and a first power unit arranged at the top of the first mixing drum. The positioning seat includes a plurality of brackets abutting against the inner wall of the first mixing drum and a shaft seat fixed on the top of the bracket leg; the top end of the stirring shaft is connected to the power of the first power unit, and the end is rotatably arranged in the center of the shaft seat. The positioning seat is used to ensure the stable operation of the stirring shaft and prevent uneven stirring caused by the movement of the stirring shaft during the stirring process.

[0085] Exemplary Reagents

[0086] A highly efficient and environmentally friendly saline-alkali land improver is prepared by the above-mentioned highly efficient and environmentally friendly saline-alkali land improver preparation method.

[0087] Example 1

[0088] In this embodiment, acidic phosphogypsum is used as a saline-alkali land improver.

[0089] Example 2

[0090] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0091] S2. The composite microbial agent, glucose solution and hydrothermal charcoal are mixed in a feed ratio of 2:1:4, stirred and dispersed, and then dried to obtain a composite biological agent.

[0092] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent and amino acid in a feed ratio of 3:7:3:1 to obtain a saline-alkali land improver.

[0093] Example 3

[0094] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0095] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0096] S3, the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 6:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0097] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0098] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent and amino acid in a feed ratio of 3:7:3:1 to obtain a saline-alkali land improver.

[0099] Example 4

[0100] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0101] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0102] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0103] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0104] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent and amino acid in a feed ratio of 3:7:3:1 to obtain a saline-alkali land improver.

[0105] Example 5

[0106] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0107] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0108] S3, the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 3:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0109] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0110] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent and amino acid in a feed ratio of 3:7:3:1 to obtain a saline-alkali land improver.

[0111] Example 6

[0112] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0113] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0114] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0115] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0116] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and ferrous sulfate in a feeding ratio of 4:7:3:1:0.5:0.5 to obtain a saline-alkali land improver.

[0117] Example 7

[0118] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0119] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0120] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0121] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0122] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and ferrous sulfate in a feeding ratio of 4:7:3:1:1:1 to obtain a saline-alkali land improver.

[0123] Example 8

[0124] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0125] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0126] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0127] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0128] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and ferrous sulfate in a feeding ratio of 4:7:3:1:1.5:1.5 to obtain a saline-alkali land improver.

[0129] Example 9

[0130] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0131] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0132] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0133] S4. The composite microbial agent, glucose solution, hydrothermal charcoal and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0134] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and ferrous sulfate in a feeding ratio of 4:7:3:1:2:2 to obtain a saline-alkali land improver.

[0135] Example 10

[0136] S1. Alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria are respectively placed in culture medium for cultivation to obtain various bacterial agents with an effective live bacteria count of more than 100 million per milliliter, and various bacterial agents are mixed to obtain a composite microbial bacterial agent.

[0137] S2. Dissolve sodium carboxymethyl cellulose in distilled water, introduce nitrogen to exhaust the air, heat to 70°C, add potassium persulfate, and stir for 20 minutes; add γ-aminobutyric acid and magnesium sulfate in sequence, stir and heat at 70°C for 2 hours; cool to 20°C, and let stand for 60 minutes to obtain a modified sodium carboxymethyl cellulose solution.

[0138] S3. Modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan were mixed in a ratio of 4:1:1, and the mixed solution was heated to 60°C and stirred for 15 minutes. After all the components were completely dissolved, 3% glycerol and 3% calcium chloride solution were added respectively.

[0139] S4. The composite microbial agent, glucose solution, boiler biochar and coating liquid are mixed in a feed ratio of 2:1:4:1, stirred and dispersed, and then dried to obtain a composite biological agent.

[0140] S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and ferrous sulfate in a feeding ratio of 4:7:3:1:1.5:1.5 to obtain a saline-alkali land improver.

[0141] Experimental design

[0142] The test site was divided into 10 test plots, each with an area of ​​1 mu, which were recorded as test plots 1 to 10, and the saline-alkali land improvers used corresponded to the saline-alkali land improvers in Examples 1 to 10. The experimental crop was corn, and the improvement experiment was carried out for two months, with tap water used for regular irrigation. After the experiment, sampling and analysis were carried out, and the results were shown in the following table:

[0143] Table 1 Corn crop growth

[0144]

[0145]

[0146] Through the above experiments and experimental results, we can conclude that:

[0147] (1) Example 1 and Example 2: The height, stem diameter and number of leaves of corn in Example 2 are significantly higher than those in Example 1. This is because the combination of modifiers in Example 2 is more effective in promoting corn growth. Example 1 used acidic phosphogypsum as a saline-alkali land modifier, while Example 2 used a mixture of composite microbial agents, glucose solution, hydrochar and bottom mud, titanium gypsum, and amino acids as modifiers. Composite microbial agents can improve the soil microbial environment and increase soil fertility, while glucose solution and hydrochar provide carbon sources and energy for microorganisms, which help the growth and activity of microorganisms, thereby further improving soil structure and promoting crop growth.

[0148] (2) Example 2 and Examples 3 to 5: The growth of corn in Examples (3, 4, and 5) using coating liquid is generally better than that in Example 2 without coating liquid. This is because no coating liquid is used in Example 2, while coating liquid composed of modified sodium carboxymethyl cellulose solution, sodium alginate, and chitosan is used in Examples 3 to 5. The coating liquid can protect the microbial agent, improve its survival rate under adverse environmental conditions, and slowly release microorganisms through a controlled release mechanism to enhance the biological activity of biochar and the soil improvement effect. In addition, the concentration of the coating liquid (i.e., the feed ratio of each component) in Examples 3 to 5 is different. If the concentration of the coating liquid is too high, an overly tight coating layer will be formed, which will limit the contact between the microbial agent and the soil environment, thereby affecting its respiration and metabolic activity; if the concentration of the coating liquid is too low, the microbial agent will be damaged by the external environment in the soil, resulting in the inhibition of the growth of the microbial agent in the soil, and thus it cannot fully play its role in improving the soil environment. Therefore, the growth of corn in Example 4 is better than that in Examples 3 and 5.

[0149] (3) Example 4 and Examples 6 to 9: The growth of corn in Examples (6, 7, 8, 9) in which phosphate rock and iron fertilizer were added was generally better than that in Example 4 in which no phosphate rock and iron fertilizer were added. This is because phosphate rock and iron fertilizer were not added in Example 4, while different amounts of phosphate rock and iron fertilizer were added in Examples 6 to 9. As a source of phosphorus, phosphate rock can increase the POD activity of corn; and iron fertilizer can promote the antioxidant enzyme system of plants. Increasing the POD and CAT activities of corn is specifically manifested in removing excess reactive oxygen free radicals in cells by increasing the POD and CAT activities, thereby protecting the cell membrane from oxidative damage and improving its growth vitality, while optimizing the metabolic pathway of corn and improving energy utilization efficiency. In addition, the growth of corn in Example 8 is better than that in Examples 6, 7, and 9, because the addition ratios of phosphate rock and iron fertilizer in the saline-alkali land improver are different. If the amount of phosphate rock powder added is too high, it will lead to excessive accumulation of phosphorus in the soil, forming a competitive relationship with other nutrients (such as nitrogen, potassium, etc.), resulting in nutrient imbalance, affecting the absorption and utilization of other nutrients by corn, and further affecting root growth and water absorption and transportation; if the amount of phosphate rock powder added is too low, it cannot play the role of an amendment in improving the physical and chemical properties of the soil. If the amount of iron fertilizer added is too high, it will lead to soil acidification, affecting the activity of soil microorganisms and the stability of soil structure; if the amount of iron fertilizer added is too low, it will damage the antioxidant enzyme system and reduce the resistance of corn to salt stress.

[0150] (4) Example 8 vs. Example 10: The growth of corn in Example 8 using hydrochar was significantly better than that in Example 10 using boiler biochar. This is because hydrochar has a better pore structure and adsorption performance, which can more effectively adsorb and fix harmful substances in the soil, while providing the carbon source and energy required by microorganisms. Although boiler biochar also has certain adsorption properties, its structure and performance are not as good as hydrochar. In addition, in the production of boiler biochar, high temperature leads to the loss of acidic functional groups and the formation of alkaline functional groups, so the pH value of boiler biochar will be higher than that of hydrochar.

[0151] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing an efficient and environmentally friendly saline-alkali land conditioner, characterized in that: The following steps are involved: S1, placing several kinds of microbial agents in culture medium for cultivation respectively, and mixing them after the cultivation period to obtain a composite microbial agent; S2, dissolving sodium carboxymethyl cellulose in distilled water for modification to obtain a modified sodium carboxymethyl cellulose solution; S3, mixing the modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan to obtain a coating solution; S4, mixing the composite microbial agent, glucose solution, biochar and coating liquid, stirring and dispersing, and then drying to obtain a composite biological agent; S5. Evenly mix the bottom mud, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer to obtain a saline-alkali land conditioner.

2. The method for preparing a highly efficient and environmentally friendly saline-alkali land conditioner according to claim 1, characterized in that: The microbial agent in step S1 includes one or more of alkali-resistant Bacillus, Bacillus licheniformis, Bacillus mucilaginosus, nitrogen-fixing bacteria, Trichoderma, salt-tolerant actinomycetes and lactic acid bacteria.

3. The method for preparing a highly efficient and environmentally friendly saline-alkali land conditioner according to claim 1, characterized in that: The preparation method of the modified sodium carboxymethyl cellulose solution in step S2 is as follows: after dissolving sodium carboxymethyl cellulose in distilled water, nitrogen is introduced to exhaust the air, the temperature is raised to 65-75° C., potassium persulfate is added, and stirring is performed for 20-40 minutes; γ-aminobutyric acid and magnesium sulfate are added in sequence, and the mixture is stirred and heated at a temperature of 65-75° C. for 2-4 hours; the mixture is cooled to 20-26° C., and allowed to stand for 40-60 minutes to obtain the modified sodium carboxymethyl cellulose solution.

4. The method for preparing a highly efficient and environmentally friendly saline-alkali land modifier according to claim 1, characterized in that: The preparation method of the coating liquid in step S3 is: after mixing modified sodium carboxymethyl cellulose solution, sodium alginate and chitosan, heating the mixed solution to 50-60°C and stirring; after all the components are completely dissolved, adding glycerol to adjust the viscosity and moisture retention of the coating liquid, adding a calcium chloride solution with a mass fraction of 1%-3% to adjust the strength and stability of the coating liquid; wherein the viscosity of the modified sodium carboxymethyl cellulose solution is between 10-50mPa.s; the mass proportions of the modified sodium carboxymethyl cellulose solution, sodium alginate, chitosan, glycerol and calcium chloride solution in the coating liquid are: 40-80%, 12-25%, 12-25%, 3-8% and 3-8%, respectively.

5. The method for preparing a highly efficient and environmentally friendly saline-alkali land conditioner according to claim 1, characterized in that: The biochar preparation method in step S4 is hydrothermal carbonization or biomass boiler combustion.

6. The method for preparing a highly efficient and environmentally friendly saline-alkali land conditioner according to claim 5, characterized in that: In step S4, the mass proportions of the composite microbial agent, glucose solution, biochar and coating liquid are 20-40%, 5-15%, 20-40% and 20-40% respectively; the drying method of the mixture is one of spray drying, vacuum drying and freeze drying.

7. The method for preparing a highly efficient and environmentally friendly saline-alkali land conditioner according to claim 1, characterized in that: In step S5, the mass proportions of sludge, titanium gypsum, composite biological agent, amino acid, phosphate rock powder and iron fertilizer are 25-40%, 35-50%, 15-25%, 5-10%, 6-12% and 6-12%, respectively.

8. An efficient and environmentally friendly saline-alkali land conditioner preparation device, based on the preparation method according to any one of claims 1 to 7, characterized in that: It comprises a first mixing cylinder (1), a vacuum drying box (2) and a second mixing cylinder (3); The first mixing barrel (1) comprises a first barrel (11), a first material inlet (12) arranged at the top of the first barrel (11), a first material outlet (13) arranged at the bottom of the first barrel (11), a first stirring component (14) arranged inside the first barrel (11), and a temperature control component (15) arranged inside the first barrel (11); The vacuum drying box (2) comprises a body (21), a vacuum chamber (22) installed at the upper part of the body (21), and a vacuum pumping assembly (23) installed at the lower part of the body (21); The second mixing barrel (3) comprises a second barrel (31), a second feed port (32) arranged at the top of the second barrel (31), a second discharge port (33) arranged at the bottom of the second barrel (31), and a second stirring assembly (34) arranged in the second barrel (31).

9. The highly efficient and environmentally friendly saline-alkali land conditioner preparation device according to claim 8, characterized in that: The temperature control component (15) comprises a medium tube (151); the medium tube (151) is spirally arranged around the axis of the first mixing cylinder (1) and abuts against the inner cylinder wall of the first mixing cylinder (1); the head end and the tail end of the medium tube (151) pass through the inner wall of the first mixing cylinder (1) and extend outward to form a medium inlet (152) and a medium outlet (153) respectively.

10. An efficient and environmentally friendly saline-alkali land improver, characterized in that: The invention is prepared by the method for preparing a highly efficient and environmentally friendly saline-alkali land improver according to any one of claims 1 to 7.

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