Alkali salt settling agent as well as preparation method and application thereof

Abstract

The invention provides an alkali salt settling agent as well as a preparation method and application thereof, and belongs to the technical field of saline-alkali soil improvement. The alkali salt settling agent is prepared from the following raw materials in parts by weight: 20-25 parts of humic acid, 20-25 parts of modified medical stone, 18-23 parts of tribulus terrestris powder, 7-10 parts of common gendarussa herb bone meal, 5-7 parts of barium sulfate, 3-5 parts of polyacrylamide and 3-5 parts of a compound microbial preparation. According to the method, the saline-alkali soil is improved by adopting a technology combining a biological means and a chemical means, so that the EPS value of the soil is reduced to 5.1% from 15.2% at most, the pH value of the soil is also reduced to a normal level from 9.3 in the past, and the saline-alkali soil is changed from severe salinization to light salinization; the alkali salt settling agent provided by the invention has a very remarkable effect on improvement of saline-alkali soil.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali soil improvement, and in particular to an alkali-salt sedimentation agent and a preparation method and application thereof. Background Art

[0002] Soil salinization is a land resource problem that the world is facing. China has a huge area of ​​saline-alkali land, which is widely distributed and has a wide variety of types. Timely management of saline-alkali land resources to improve the ecological environment plays a very important role in the economic, social and ecological sustainable development of local areas. It is also an important measure to promote the sustainable development of China's agriculture. Soil salinization is an environmental geological phenomenon that not only disrupts the ecosystem and affects agricultural production, but also leads to the decline of the economic level in saline-alkali areas. The formation of soil salinization is divided into natural factors and human factors. Soil salinization is actually caused by soluble salts dissolved in the soil and stored in the soil surface. Under normal circumstances, groundwater and soil water maintain a certain dynamic balance, and the ion content in the surface soil is relatively stable. Once this stable state is destroyed, it is easy to form saline-alkali land. Salt in saline-alkali land accumulates inside and on the surface of the soil, and the physical and chemical properties of the soil deteriorate, such as decreased structural adhesion, high soil bulk density, poor air permeability, and poor activity of aerobic microorganisms in the soil. This further aggravates the accumulation of salt in the surface soil, inhibits plant growth and development, and even leads to plant death and crop yield reduction.

[0003] In response to the problem of soil salinization, my country's existing improvement technologies include: water conservancy improvement measures such as establishing a complete drainage and irrigation system, reducing soil salinity through irrigation, flood diversion and silt release, combining wells, ditches and canals, using machine wells to extract groundwater for irrigation, leaching salt in the surface soil to below the cultivated layer, while lowering the groundwater level and reducing the accumulation of salt in the soil surface; agricultural technology improvement measures such as deep plowing, loosening the cultivated layer, cutting off soil capillaries, reducing soil moisture evaporation, effectively controlling soil salt return, leveling the land to allow water to infiltrate evenly, and increasing rainfall salt and The effect of irrigation and salt washing is to prevent soil salinization and increase the application of organic fertilizers; chemical improvement measures such as the use of improvers such as calcium sulfate, gypsum, humic acid, etc., to neutralize soil pH and improve soil structure, and apply special fertilizers such as urea phosphate and humic acid to increase humus in the soil and reduce the damage of salt to plants; biological improvement measures such as planting salt-tolerant plants: such as alfalfa, ryegrass, etc., absorb and transfer salt through their own growth metabolism, gradually improve the soil environment, and plant trees to improve soil fertility, improve the microclimate of farmland, reduce surface water evaporation, and inhibit salt return.

[0004] Judging from the saline-alkali land improvement methods currently commonly used in China, the main problems are single function, high investment cost, slow improvement speed of 3-5 years to be effective, poor salt reduction effect, and difficulty in comprehensive promotion. Summary of the invention

[0005] In view of this, the present invention provides an alkali salt precipitator, comprising the following raw materials in parts by weight: 20-25 parts of humic acid, 20-25 parts of modified medical stone, 18-23 parts of Tribulus terrestris powder, 7-10 parts of Osmanthus fragrans powder, 5-7 parts of barium sulfate, 3-5 parts of polyacrylamide, and 3-5 parts of a composite microbial preparation.

[0006] Preferably, the humic acid is selected from at least one of fulvic acid, black humic acid and palmitic acid.

[0007] Preferably, the preparation method of the modified medical stone comprises: crushing the medical stone to a particle size of 20-50 μm, then placing it in hydrochloric acid and applying ultrasonic assisted soaking for 3-4 hours, the power of the ultrasonic wave is 60-100 W, washing with deionized water, and then roasting at 350-420° C. for 4-6 hours, cooling to room temperature and soaking it in hydrogen peroxide with a mass concentration of 8-10% for 3-4 hours, then washing it with deionized water until it is neutral and then drying it, then adding hexadecyltrimethylammonium bromide solution equivalent to 3-5% of the weight of the medical stone and 2-3% of polyethylene glycol, stirring at a speed of 2000-3000 r / min for 10-20 minutes, filtering and drying to obtain the modified medical stone.

[0008] Preferably, the particle size of the Tribulus terrestris powder is 2-5 mm, and the moisture content is 2-5%.

[0009] Preferably, the particle size of the small bone powder is 2.5-6 mm, and the moisture content is 2-5%.

[0010] Preferably, the polyacrylamide is anionic polyacrylamide.

[0011] Preferably, the composite microbial preparation comprises Chaetomium, Trichoderma and Cryptococcus.

[0012] Preferably, the mass ratio of Chaetomium, Trichoderma and Cryptococcus in the composite microbial preparation is 2-5:1-3:0.1-0.5.

[0013] The invention also provides a preparation method of the alkali salt sedimentation agent, which comprises the steps of uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Osmanthus fragrans powder, barium sulfate and polyacrylamide in proportion, granulating, screening, drying and cooling.

[0014] The alkali-salt sedimentation agent provided by the present invention can be used to improve saline-alkali land with high salinity, high alkalinity, no sedimentation, poor soil permeability and the like.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a technology combining biological means and chemical means to improve saline-alkali land, effectively regulates the physical and chemical properties of saline-alkali land, and can also improve the microenvironment in saline-alkali soil, enhance the disease resistance of crops, improve crop quality, and increase yield. The invention combines modified medical stone with a composite microbial preparation to promote the release of metal ions in the soil through exchange, thereby reducing the salt content. The composite microorganisms carried by the porous carrier have an adsorption chelation effect of the extracellular enzymes generated by the metabolic activities, so that the salt in the soil is mineralized, thereby achieving the effect of reducing the salt content of saline-alkali land. The composite microbial preparation added in the formula of the invention can secrete acidic substances, can effectively neutralize the alkaline components in the soil, and does not cause any harm to plants and the soil itself, which is in line with the future development direction of green agriculture. At the same time, the composite microbial preparation used in the invention has a good preventive and therapeutic effect on crop diseases, and can effectively prevent and control the occurrence of crop seedling diseases. The tribulus terrestris powder, small schizonepeta powder and humic acid added in the formula of the invention have the effects of synergistically adsorbing salt in the soil, reducing the salt content in the saline-alkali land, and improving soil fertility. The invention promotes the formation of soil aggregate structure, increases soil porosity, enhances soil permeability and air permeability, balances pH value, helps to wash out salt, and inhibits salt return. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a comparison chart of the ESP values ​​of the soil after 60 days of using the alkali salt precipitants prepared in Examples 1-5 of the present invention and Comparative Examples 1-6.

[0017] Figure 2 It is a comparison chart of the pH value of the soil after 60 days of using the alkali salt precipitants prepared in Examples 1-5 of the present invention and Comparative Examples 1-6. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. 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 belong to the scope of protection of the present invention.

[0019] The experimental methods or test methods described in the following examples are conventional methods unless otherwise specified; the raw materials and auxiliary agents are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified.

[0020] The invention provides an alkali salt sedimentation agent, which comprises the following raw materials in parts by weight: 20-25 parts of humic acid, 20-25 parts of modified medical stone, 18-23 parts of tribulus terrestris powder, 7-10 parts of scutellaria baicalensis powder, 5-7 parts of barium sulfate, 3-5 parts of polyacrylamide and 3-5 parts of a composite microbial preparation.

[0021] In the present invention, the alkali salt precipitant preferably comprises the following raw materials in parts by weight: 21-23 parts of humic acid, 21-23 parts of modified medical stone, 19-21 parts of Tribulus terrestris powder, 8-9 parts of Osmanthus fragrans powder, 6-7 parts of barium sulfate, 4-5 parts of polyacrylamide, and 4-5 parts of composite microbial preparation.

[0022] In the present invention, the humic acid is selected from at least one of fulvic acid, black humic acid and palmitic acid, and the humic acid is preferably fulvic acid.

[0023] In the present invention, the preparation method of the modified medical stone comprises: crushing the medical stone to a particle size of 20-50 μm, then placing it in hydrochloric acid and applying ultrasonic assisted soaking for 3-4 hours, the power of the ultrasonic wave is 60-100W, washing with deionized water, and then roasting at 350-420° C. for 4-6 hours, cooling to room temperature and soaking it in hydrogen peroxide with a mass concentration of 8-10% for 3-4 hours, then washing it with deionized water until it is neutral and drying it, then adding hexadecyltrimethylammonium bromide solution equivalent to 3-5% of the weight of the medical stone and 2-3% of polyethylene glycol, stirring it at a speed of 2000-3000 r / min for 10-20 minutes, filtering and drying it to obtain the modified medical stone.

[0024] The present invention utilizes a modifier to modify medical stone, and greatly improves the adsorption and dissolution function, ion exchange capacity and biological activity of medical stone, can activate the calcium ions solidified in the soil, adsorb and remove excess sodium ions, accelerate the activation and decomposition of sparingly soluble phosphates in saline-alkali soils, contribute to the formation of soil aggregates, and inhibit salt return. The modified medical stone reaches the effect of reducing the salt content in the soil by exerting an ion exchange effect. In addition, the formula of the present invention contains a large amount of carbon ions and hydrogen ions, wherein the hydrogen ions can react with carbonate and bicarbonate in the soil, play the effect of reducing the pH value of the soil, and the carbon ions can improve the air permeability of the soil, promote the growth and development of crops, balance the pH value of the soil, and further reduce the salinity of the soil.

[0025] In the present invention, the particle size of the Tribulus terrestris powder is 2-5 mm, preferably 3 mm, and the moisture content is 2-5%, preferably 3%.

[0026] In the present invention, the particle size of the small bone powder is 2.5-6mm, preferably 3mm, and the moisture content is 2-5%, preferably 3%.

[0027] In the present invention, the cooling includes but is not limited to natural cooling to room temperature.

[0028] Preferably, the polyacrylamide is anionic polyacrylamide. The anionic polyacrylamide used in the formula of the present invention easily reacts with water in the soil to form a viscous colloid, which plays a role in adjusting the permeability, porosity and moisture content of the soil, reshaping the soil structure, improving the stability of aggregates, reducing surface runoff, and promoting crop yields.

[0029] In the present invention, the composite microbial preparation comprises Chaetomium, Trichoderma and Cryptococcus, wherein the mass ratio of Chaetomium, Trichoderma and Cryptococcus is 2-5:1-3:0.1-0.5.

[0030] The inventors have found that the composite microbial preparation obtained by compounding Chaetomium, Trichoderma and Cryptococcus in the above proportion can effectively promote the dissolution of nutrients in modified medical stone, which is beneficial to the absorption and utilization of crops. At the same time, the acidic substances produced in its metabolic activities can neutralize the alkalinity in the soil, balance the pH value, and help improve saline-alkali soil.

[0031] In the present invention, the Chaetomium is one or more of Chaetomium globosum, Chaetomium hornense, and Chaetomium spiralis, and the effective viable bacteria count in the powder of the Chaetomium is 8×10 9 CFU / g.

[0032] In the present invention, the Trichoderma is one or more of Trichoderma longibrachiatum, Trichoderma harzianum, and Trichoderma viride, and the effective viable bacteria count in the Trichoderma powder is 9×10 9 CFU / g.

[0033] In the present invention, the cryptococcus is at least one of Cryptococcus neoformans and Cryptococcus gattii, and the effective viable count of the cryptococcus powder is 8×10 9 CFU / g.

[0034] The invention also provides a preparation method of the alkali salt sedimentation agent, which comprises the steps of uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Osmanthus fragrans powder, barium sulfate and polyacrylamide in proportion, granulating, screening, drying and cooling.

[0035] The alkali-salt sedimentation agent provided by the invention can be used to improve the defects of saline-alkali land, such as high salinity, high alkalinity, no sedimentation, and poor soil permeability.

[0036] The application amount of the alkali salt sedimentation agent of the present invention is 50-150kg / hm 2 , adjust the application amount according to actual soil conditions.

[0037] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. 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.

[0038] Example 1

[0039] An alkali salt sedimentation agent is composed of the following raw materials in parts by weight: 20 parts of fulvic acid, 20 parts of modified medical stone, 18 parts of Tribulus terrestris powder, 7 parts of Osmanthus fragrans powder, 5 parts of barium sulfate, 3 parts of anionic polyacrylamide, and 3 parts of a composite microbial preparation;

[0040] The preparation method of the modified medical stone is as follows: crushing the medical stone to a particle size of 20 μm, then placing the medical stone in hydrochloric acid and applying ultrasonic wave to soak for 3 hours, wherein the power of the ultrasonic wave is 60W, washing with deionized water, and then roasting at 350° C. for 6 hours, cooling to room temperature, soaking in hydrogen peroxide with a mass concentration of 8% for 3 hours, washing with deionized water until neutral, and drying, then adding 3% hexadecyltrimethylammonium bromide solution and 2% polyethylene glycol equivalent to the weight of the medical stone, stirring at a speed of 2000 r / min for 20 minutes, filtering, and drying to obtain the modified medical stone;

[0041] The particle size of the Tribulus terrestris powder is 2 mm, and the moisture content is 3%;

[0042] The particle size of the small bone powder is 2.5mm and the moisture content is 3%;

[0043] The composite microbial preparation consists of Chaetomium, Trichoderma and Cryptococcus in a mass ratio of 2:1:0.1.

[0044] The preparation method of the alkali salt sedimentation agent comprises the following steps: uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Ostriata sibiricum powder, barium sulfate and polyacrylamide in proportion, granulating, sieving, drying at 60° C. and cooling to room temperature.

[0045] Example 2

[0046] An alkali salt sedimentation agent is composed of the following raw materials in parts by weight: 25 parts of humic acid, 25 parts of modified medical stone, 23 parts of Tribulus terrestris powder, 10 parts of Osmanthus fragrans powder, 7 parts of barium sulfate, 5 parts of anionic polyacrylamide, and 5 parts of a composite microbial preparation;

[0047] The preparation method of the modified medical stone is as follows: crushing the medical stone to a particle size of 50 μm, then placing the medical stone in hydrochloric acid and applying ultrasonic wave to soak for 4 hours, wherein the power of the ultrasonic wave is 100 W, washing with deionized water, and then roasting at 420° C. for 6 hours, cooling to room temperature, soaking in hydrogen peroxide with a mass concentration of 10% for 4 hours, washing with deionized water to neutrality, and then drying, then adding hexadecyl trimethyl ammonium bromide solution equivalent to 5% of the weight of the medical stone and 3% of polyethylene glycol, stirring at a speed of 3000 r / min for 20 minutes, filtering, and drying to obtain the modified medical stone;

[0048] The particle size of the Tribulus terrestris powder is 5 mm and the moisture content is 5%;

[0049] The particle size of the small bone powder is 6mm and the moisture content is 5%;

[0050] The composite microbial preparation consists of Chaetomium, Trichoderma and Cryptococcus in a mass ratio of 5:3:0.5.

[0051] The preparation method of the alkali salt sedimentation agent comprises the following steps: uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Ostriata sibiricum powder, barium sulfate and polyacrylamide in proportion, granulating, sieving, drying at 60° C. and cooling to room temperature.

[0052] Example 3

[0053] An alkali salt sedimentation agent is composed of the following raw materials in parts by weight: 20 parts of palmitic acid, 20 parts of modified medical stone, 18 parts of Tribulus terrestris powder, 7 parts of Osmanthus fragrans powder, 5 parts of barium sulfate, 3 parts of anionic polyacrylamide, and 3 parts of a composite microbial preparation;

[0054] The preparation method of the modified medical stone is as follows: crushing the medical stone to a particle size of 20 μm, then placing the medical stone in hydrochloric acid and applying ultrasonic wave to soak for 3 hours, wherein the power of the ultrasonic wave is 800 W, washing with deionized water, and then roasting at 380° C. for 6 hours, cooling to room temperature, soaking in hydrogen peroxide with a mass concentration of 10% for 4 hours, washing with deionized water to neutrality, and then drying, adding hexadecyl trimethylammonium bromide solution equivalent to 3% of the weight of the medical stone and 2% of polyethylene glycol, stirring at a speed of 3000 r / min for 20 minutes, filtering, and drying to obtain the modified medical stone;

[0055] The particle size of the Tribulus terrestris powder is 3 mm, and the moisture content is 3%;

[0056] The particle size of the small bone powder is 3mm and the moisture content is 4%;

[0057] The composite microbial preparation consists of Chaetomium, Trichoderma and Cryptococcus in a mass ratio of 3:2:0.3.

[0058] The preparation method of the alkali salt sedimentation agent comprises the following steps: uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Ostriata sibiricum powder, barium sulfate and polyacrylamide in proportion, granulating, sieving, drying at 60° C. and cooling to room temperature.

[0059] Example 4

[0060] An alkali salt sedimentation agent is composed of the following raw materials in parts by weight: 23 parts of fulvic acid, 22 parts of modified medical stone, 20 parts of Tribulus terrestris powder, 8 parts of Osmanthus fragrans powder, 6 parts of barium sulfate, 4 parts of anionic polyacrylamide, and 4 parts of a composite microbial preparation;

[0061] The preparation method of the modified medical stone is as follows: crushing the medical stone to a particle size of 30 μm, then placing the medical stone in hydrochloric acid and applying ultrasonic wave to soak for 3.5 hours, wherein the power of the ultrasonic wave is 90W, washing with deionized water, and then roasting at 420° C. for 4 hours, cooling to room temperature, soaking in hydrogen peroxide with a mass concentration of 10% for 3 hours, washing with deionized water until neutral, and drying, then adding hexadecyl trimethylammonium bromide solution equivalent to 3% of the weight of the medical stone and 3% of polyethylene glycol, stirring at a speed of 3000 r / min for 15 minutes, filtering, and drying to obtain the modified medical stone;

[0062] The particle size of the Tribulus terrestris powder is 4 mm and the moisture content is 3%;

[0063] The particle size of the small bone powder is 3mm and the moisture content is 3%;

[0064] The composite microbial preparation consists of Chaetomium, Trichoderma and Cryptococcus in a mass ratio of 4:1:0.1.

[0065] The preparation method of the alkali salt sedimentation agent comprises the following steps: uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Ostriata sibiricum powder, barium sulfate and polyacrylamide in proportion, granulating, sieving, drying at 60° C. and cooling to room temperature.

[0066] Example 5

[0067] An alkali salt sedimentation agent is composed of the following raw materials in parts by weight: 24 parts of fulvic acid, 24 parts of modified medical stone, 22 parts of Tribulus terrestris powder, 9 parts of Osmanthus fragrans powder, 7 parts of barium sulfate, 5 parts of anionic polyacrylamide, and 5 parts of a composite microbial preparation;

[0068] The preparation method of the modified medical stone is as follows: crushing the medical stone to a particle size of 45 μm, then placing the medical stone in hydrochloric acid and applying ultrasonic wave to soak for 3.5 hours, wherein the power of the ultrasonic wave is 80W, washing with deionized water, and then roasting at 420° C. for 5 hours, cooling to room temperature, soaking in hydrogen peroxide with a mass concentration of 10% for 4 hours, washing with deionized water until neutral, and then drying, adding hexadecyl trimethyl ammonium bromide solution equivalent to 3% of the weight of the medical stone and 3% of polyethylene glycol, stirring at a speed of 3000 r / min for 18 minutes, filtering, and drying to obtain the modified medical stone;

[0069] The particle size of the Tribulus terrestris powder is 5 mm and the moisture content is 5%;

[0070] The particle size of the small bone powder is 26mm and the moisture content is 4%;

[0071] The composite microbial preparation consists of Chaetomium, Trichoderma and Cryptococcus in a mass ratio of 2:3:0.5.

[0072] The preparation method of the alkali salt sedimentation agent comprises the following steps: uniformly mixing the composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Ostriata sibiricum powder, barium sulfate and polyacrylamide in proportion, granulating, sieving, drying at 60° C. and cooling to room temperature.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Example 1 is that unmodified medical stone is added, and the other steps are consistent with Example 1.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 1 is that no Tribulus terrestris powder is added, and the remaining steps are consistent with Example 1.

[0077] Comparative Example 3

[0078] The difference between this comparative example and Example 1 is that no small bone powder is added, and the other steps are consistent with Example 1.

[0079] Comparative Example 4

[0080] The difference between this comparative example and Example 1 is that the composite microbial preparation does not contain Chaetomium, and the other steps are consistent with Example 1.

[0081] Comparative Example 5

[0082] The difference between this comparative example and Example 1 is that the composite microbial preparation does not contain Trichoderma, and the other steps are consistent with Example 1.

[0083] Comparative Example 6

[0084] The difference between this comparative example and Example 1 is that the composite microbial preparation does not contain Cryptococcus, and the other steps are consistent with Example 1.

[0085] The alkali salt precipitators prepared in Examples 1-5 and Comparative Examples 1-6 were applied in a severely saline-alkali area, wherein the amount of the alkali salt precipitators applied in the Examples and Comparative Examples during the test was the same, and the ESP value test and pH value test of the soil were respectively carried out after 60 days, and the results are shown in Table 1:

[0086] Table 1 Test results of ESP value and pH value of soil after 60 days of alkali salt sedimentation agents prepared in Examples 1-5 and Comparative Examples 1-6

[0087] Group ESP value of soil (%) Soil pH Test soil 15.2 9.3 Example 1 5.1 7.1 Example 2 5.8 7.5 Example 3 5.9 7.2 Example 4 5.3 7.9 Example 5 5.1 7.8 Comparative Example 1 12.7 8.2 Comparative Example 2 11.5 8.0 Comparative Example 3 10.2 8.3 Comparative Example 4 12.5 8.9 Comparative Example 5 10.9 8.5 Comparative Example 6 10.1 8.6

[0088] From Table 1 and Figure 1 , Figure 2 It can be seen that after the alkali-salt precipitator prepared in Examples 1-5 was used to improve the saline-alkali land, the salinity of the soil decreased significantly, the EPS value of the soil decreased from 15.2% to 5.1% at most, the pH value of the soil decreased from the original 9.3 to a normal level, and the saline-alkali soil was transformed from severe salinization to mild salinization. It can be seen that the alkali-salt precipitator provided by the present invention plays a very significant role in the improvement of saline-alkali soil.

[0089] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An alkali salt precipitant, characterized in that The invention comprises the following raw materials in parts by weight: 20-25 parts of humic acid, 20-25 parts of modified medical stone, 18-23 parts of tribulus terrestris powder, 7-10 parts of scutellaria baicalensis powder, 5-7 parts of barium sulfate, 3-5 parts of polyacrylamide and 3-5 parts of composite microbial preparation.

2. The alkali salt sedimentation agent according to claim 1, characterized in that The humic acid is selected from at least one of fulvic acid, black humic acid and palmitic acid.

3. The alkali salt sedimentation agent according to claim 1, characterized in that The preparation method of the modified medical stone comprises: crushing the medical stone to a particle size of 20-50 μm, then placing the medical stone in hydrochloric acid and simultaneously applying ultrasonic assisted soaking for 3-4 hours, wherein the power of the ultrasonic wave is 60-100 W, washing with deionized water, and then roasting at 350-420 DEG C for 4-6 hours, cooling to room temperature and soaking in hydrogen peroxide with a mass concentration of 8-10% for 3-4 hours, then washing with deionized water until neutral and drying, then adding hexadecyltrimethylammonium bromide solution equivalent to 3-5% of the weight of the medical stone and 2-3% of polyethylene glycol, stirring at a speed of 2000-3000 r / min for 10-20 minutes, filtering and drying to obtain the modified medical stone.

4. The alkali salt sedimentation agent according to claim 1, characterized in that: The particle size of the Tribulus terrestris powder is 2-5 mm, and the moisture content is 2-5%.

5. The alkali salt sedimentation agent according to claim 1, characterized in that: The particle size of the small bone powder is 2.5-6mm, and the moisture content is 2-5%.

6. The alkali salt sedimentation agent according to claim 1, characterized in that: The polyacrylamide is anionic polyacrylamide.

7. The alkali salt sedimentation agent according to claim 1, characterized in that: The composite microbial preparation comprises Chaetomium, Trichoderma and Cryptococcus.

8. The alkali salt sedimentation agent according to claim 1, characterized in that: The mass ratio of Chaetomium, Trichoderma and Cryptococcus in the composite microbial preparation is 2-5:1-3:0.1-0.

5.

9. The method for preparing the alkali salt sedimentation agent according to any one of claims 1 to 8, characterized in that: The composite microbial preparation, modified medical stone, humic acid, Tribulus terrestris powder, Osmanthus fragrans powder, barium sulfate and polyacrylamide are uniformly mixed in proportion, granulated, sieved, dried and cooled.

10. Use of the alkali salt precipitator according to any one of claims 1 to 8 or the alkali salt precipitator prepared by the method according to claim 9 in improving saline-alkali land.

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