Composite soil conditioner, its preparation method and application
By combining the acidic activating matrix and jaundice minerals in the composite soil conditioner, the problems of potassium supply and soil structure improvement in high-altitude permafrost regions are solved, achieving slow release of potassium and soil aggregation, improving the soil's water and fertilizer retention capacity, and providing efficient ecological restoration effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHILAN ECOLOGICAL ENVIRONMENT CONSTR CO LTD
- Filing Date
- 2026-02-06
- Publication Date
- 2026-05-29
AI Technical Summary
In high-altitude permafrost regions, the available potassium content in the soil is low, the release rate of traditional potassium fertilizers does not match the needs of plants, and the soil structure is severely degraded. Existing soil conditioners have limited effectiveness in low-temperature environments.
A composite soil conditioner is made by combining superphosphate, powdered humic acid, fulvic acid metal complex with potassium ferrous sulfate minerals to form an acidic activated matrix, and adding lignin sulfonate as a binding medium. The mixture is then processed through dry mixing, granulation, and low-temperature curing to achieve the slow release of potassium ions and the improvement of soil structure.
It achieves continuous potassium release and improves soil structure stability, promotes soil aggregation, enhances soil water and fertilizer retention capacity, and provides an efficient ecological restoration solution for high-altitude permafrost regions.
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Figure CN121652816B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of ecological technology, and in particular to a composite soil conditioner, its preparation method, and its application. Background Technology
[0002] The soil ecosystems in high-altitude permafrost regions are extremely fragile due to their unique low-temperature environment, facing the dual challenges of soil nutrient depletion and structural degradation. The average annual temperature in these regions is below 0℃, resulting in potassium in the soil primarily existing as insoluble minerals, with available potassium content generally below 80 mg / kg, severely restricting plant growth. Simultaneously, the soil aggregate structure is poorly developed, with a low proportion of water-stable aggregates, leading to poor water and fertilizer retention capacity and significant nutrient loss. Existing soil improvement technologies have significant limitations. Traditional fast-acting potassium fertilizers release too quickly in the low-temperature environment of permafrost regions, with potassium loss exceeding 50% within 30 days after application, and they cannot solve the problem of soil structural degradation. While single soil conditioners can improve soil physical properties in the short term, they lack a sustained potassium supply capacity, making it difficult to meet the long-term growth needs of plants. Some compound conditioners decompose slowly under high-altitude conditions, resulting in a severe mismatch between nutrient release and plant demand.
[0003] To address the technical needs of soil improvement in high-altitude mining areas, existing solutions often suffer from limitations such as limited functionality or poor environmental adaptability. For example, Chinese patent application CN202210431391.7, entitled "A Method for Applying Organic Fertilizer to Alfalfa Grasslands in High-Altitude Areas," primarily relies on fermented livestock and poultry manure products. While this increases organic matter, its contribution to soil aggregate formation and pH buffering is limited, and the nutrient release rate is difficult to control under high-altitude conditions. Similarly, Chinese patent application CN202011183731.6, entitled "A Soil Conditioner Containing Vermiculite and Its Preparation Method," uses a compound of vermiculite, animal manure, and beneficial bacteria. While this approach balances fertilization and soil structure improvement, its potassium release rate still cannot match the short growth cycle of plants in high-altitude areas, and potassium release slows down in low-temperature environments. These technologies fail to systematically solve the problems of soil infertility and poor effective soil aggregate structure in high-altitude permafrost regions. Summary of the Invention
[0004] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a composite soil conditioner, its preparation method and application. By compounding superphosphate, powdered humic acid and fulvic acid metal complex in a specific ratio to form an acidic activated matrix, jaundice mineral is introduced as a slow-release carrier of potassium fertilizer, and lignin sulfonate is added as a binding and dispersing medium. The conditioner can realize the continuous release of potassium ions. At the same time, the mineral skeleton remaining after potassium release reacts with calcium ions and organic matter in the soil to promote the formation of water-stable aggregate structure, thereby achieving synergistic improvement of potassium slow-release supply and soil structure construction.
[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:
[0006] A composite soil conditioner comprises the following components in parts by weight: 30-40 parts of superphosphate, 20-25 parts of powdered humic acid, 20-25 parts of fulvic acid metal complex, 10-25 parts of potassium ferrous sulfate and 5-8 parts of lignin sulfonate.
[0007] According to one aspect of the present invention, the fulvic acid metal complex contains ≥40% fulvic acid, ≥6% metal element content, and has a pH value of 4.0 to 6.0.
[0008] According to one aspect of the invention, the metallic element is iron or zinc.
[0009] According to one aspect of the present invention, the jaundice alum has a purity of ≥70% and a particle size of 150 mesh to 300 mesh.
[0010] According to one aspect of the present invention, the powdered humic acid has an organic matter content of ≥80%, a humic acid content of ≥65%, and a pH value of 3.5 to 6.0.
[0011] According to one aspect of the invention, the lignin sulfonate is one or a combination of calcium lignin sulfonate, sodium lignin sulfonate, magnesium lignin sulfonate, and ammonium lignin sulfonate.
[0012] According to one aspect of the present invention, the superphosphate is an acidic, fast-acting phosphate fertilizer with an effective phosphorus content of 12% to 21%.
[0013] A method for preparing a composite soil conditioner includes the following steps:
[0014] Superphosphate, powdered humic acid, and fulvic acid metal complex were pulverized, sieved, and mixed to obtain an acid-activated matrix.
[0015] The acidic activated matrix is dry-mixed with potassium ferrous sulfate and lignin sulfonate, granulated, dried and solidified to obtain a composite soil conditioner.
[0016] According to one aspect of the invention, the drying and curing includes drying in a drying oven at 50-60°C until the moisture content of the particles is less than 8%.
[0017] According to one aspect of the present invention, the above-mentioned composite soil conditioner is used in ecological restoration.
[0018] Advantages of implementing this invention:
[0019] A composite soil conditioner is produced by combining superphosphate, powdered humic acid, and a metal complex of fulvic acid in a specific ratio to form an acidic activated matrix. Potassium sulfonate minerals are then introduced as a slow-release carrier for potassium fertilizer, and lignin sulfonate is added as a binding and dispersing medium. The mixture is then processed through dry mixing, granulation, and low-temperature curing to create a multifunctional composite soil conditioner. Potassium sulfonate releases potassium ions continuously through slow hydrolysis in the soil environment. The residual mineral framework after potassium release further synergistically interacts with calcium ions and organic matter in the soil, effectively promoting the formation of water-stable aggregate structures. Therefore, this composite conditioner innovatively achieves the dual functions of slow-release potassium fertilizer and soil aggregate formation. The dynamic transformation process of potassium sulfonate simultaneously solves the problems of potassium supply and soil structure improvement. The low-temperature preparation process ensures the product's stability in cold environments, and all components are naturally transformable, making it environmentally friendly and residue-free. Meanwhile, through the slow release and retention of potassium, the soil's potassium supply capacity is effectively enhanced, soil aggregate formation is promoted, and water and fertilizer retention functions are achieved, providing an efficient and reliable overall solution for ecological restoration in high-altitude permafrost regions. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 Figures showing the available potassium content in soil under different experimental conditions;
[0022] Figure 2 Figure showing the average plant height under different experimental conditions;
[0023] Figure 3 The graph shows the saturated water content in soil under different experimental conditions.
[0024] Figure 4 The graph shows the germination rate of grass seeds under different experimental conditions;
[0025] Figure 5 The graph shows the average root-to-shoot ratio of plants under different experimental conditions.
[0026] Figure 6 Germination rate of grass seeds with different glue contents. Detailed Implementation
[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] A composite soil conditioner comprises the following components in parts by weight: 30-40 parts of superphosphate, 20-25 parts of powdered humic acid, 20-25 parts of fulvic acid metal complex, 10-25 parts of potassium ferrous sulfate and 5-8 parts of lignin sulfonate.
[0029] In practical applications, the fulvic acid-metal complex contains ≥40% fulvic acid, ≥6% metal element, and has a pH value of 4.0 to 6.0. The metal element is iron or zinc.
[0030] In practical applications, the purity of the jaundice iron alum is ≥70% and the particle size is 150 mesh to 300 mesh.
[0031] In practical applications, the superphosphate can be selected from acidic fast-acting phosphate fertilizers with an effective phosphorus content of 12% to 21%. While providing effective phosphorus, the large amount of anhydrous calcium sulfate contained in the acidic fast-acting phosphate fertilizer can serve as a soil sulfur and calcium supplement, and a small amount of free acid helps to activate trace elements in the soil.
[0032] In practical applications, the organic matter content of the powdered humic acid is ≥80%, the humic acid content is ≥65%, and the pH value is 3.5 to 6.0.
[0033] In practical applications, the lignin sulfonate serves as a binding and dispersing medium. Upon dissolution, it forms a colloidal solution that encapsulates soil particles, creating aggregate structures through cementation and filling, thereby enhancing the integrity and strength of the soil. Specifically, the lignin sulfonate can be one or a combination of calcium lignin sulfonate, sodium lignin sulfonate, magnesium lignin sulfonate, and ammonium lignin sulfonate.
[0034] A method for preparing a composite soil conditioner includes the following steps:
[0035] Superphosphate, powdered humic acid, and fulvic acid metal complex were pulverized, sieved, and mixed to obtain an acid-activated matrix.
[0036] The acidic activated matrix is dry-mixed with potassium ferrous sulfate and lignin sulfonate, granulated, dried and solidified to obtain a composite soil conditioner.
[0037] In practical applications, the dry mixing process includes mixing in a double-spiral conical mixer at a speed of 15-20 rpm for 15-20 minutes until the mixture has a uniform color and no obvious color spots.
[0038] In practical applications, the granulation process involves adding 15-25% water by weight to the mixture until the material reaches a suitable moisture level where it can be formed into a clump by hand but crumbles easily when touched. The mixture is then processed using a screw extruder or disc granulator to produce cylindrical or spherical granules with a diameter of 2-4 mm.
[0039] In practical applications, the drying and curing process is carried out in a forced-air drying oven at 50-60°C for 2-3 hours until the moisture content of the particles is below 8%.
[0040] In practical applications, the above-mentioned composite soil conditioner can be used in ecological restoration, such as applying the composite soil conditioner at a dosage of 1500-2500 g / ㎡ to the neutral to slightly alkaline or weakly alkaline mining soil in the high-altitude coal gangue permafrost area for ecological restoration.
[0041] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available or prepared according to conventional methods in the art.
[0042] Example 1
[0043] A composite soil conditioner comprises the following components in parts by weight: 35 parts superphosphate, 25 parts powdered humic acid, 25 parts iron fulvic acid, 10 parts potassium ferric sulfate, and 5 parts calcium lignosulfonate.
[0044] The preparation method of the above-mentioned composite soil conditioner includes:
[0045] Superphosphate, powdered humic acid and ferrous fulvic acid were pulverized separately and passed through an 80-mesh standard sieve, then mixed evenly to obtain an acid-activated matrix.
[0046] Add 150-300 mesh jaundice iron alum powder and calcium lignosulfonate to the acidic activated matrix, and then put it into a double-helix conical mixer. Dry mix at 15-20 rpm for 15-20 minutes until the mixture is uniform in color. Then, add water to the uniformly mixed powder for wet granulation, wherein the amount of water added is 15-25% of the mass of the uniformly mixed powder. Process it through a screw extruder or disc granulator to produce particles with a diameter of 2-4 mm, and place the particles in a forced-air drying oven at 50-60℃ for 2-3 hours to cure them until the moisture content is below 8%, thus obtaining the composite soil conditioner.
[0047] Example 2
[0048] A composite soil conditioner comprises the following components in parts by weight: 30 parts superphosphate, 20 parts powdered humic acid, 20 parts zinc fulvic acid, 15 parts potassium ferric sulfate, and 5 parts calcium lignosulfonate.
[0049] The preparation method of the above-mentioned composite soil conditioner includes:
[0050] Superphosphate, powdered humic acid, and zinc fulvate were pulverized separately and passed through an 80-mesh standard sieve. They were then mixed evenly to obtain an acid-activated matrix.
[0051] Add 150-300 mesh jaundice iron alum powder and calcium lignosulfonate to the acidic activated matrix, and put it into a double helical conical mixer. Dry mix at 15-20 rpm for 15-20 minutes until the mixture has a uniform color. Then add water to the uniformly mixed powder for wet granulation. The amount of water added is 15-25% of the mass of the uniformly mixed powder. Process it through a screw extruder or disc granulator to make particles with a diameter of 2-4 mm. Place the particles in a forced-air drying oven at 50-60℃ for 2-3 hours to cure them so that the moisture content is less than 8%, and obtain the composite soil conditioner.
[0052] Example 3
[0053] A composite soil conditioner comprises the following components in parts by weight: 40 parts superphosphate, 25 parts powdered humic acid, 25 parts iron fulvic acid, 25 parts potassium ferric sulfate, and 8 parts calcium lignosulfonate.
[0054] The preparation method of the above-mentioned composite soil conditioner includes:
[0055] Superphosphate, powdered humic acid and ferrous fulvic acid were pulverized separately and passed through an 80-mesh standard sieve, then mixed evenly to obtain an acid-activated matrix.
[0056] Add 150-300 mesh jaundice iron alum powder and calcium lignosulfonate to the acidic activated matrix, and put it into a double helical conical mixer. Dry mix at 15-20 rpm for 15-20 minutes until the mixture has a uniform color. Then add water to the uniformly mixed powder for wet granulation. The amount of water added is 15-25% of the mass of the uniformly mixed powder. Process it through a screw extruder or disc granulator to make particles with a diameter of 2-4 mm. Place the particles in a forced-air drying oven at 50-60℃ for 2-3 hours to cure them so that the moisture content is less than 8%, and obtain the composite soil conditioner.
[0057] Example 4
[0058] This embodiment provides a composite soil conditioner and its preparation method. The components and preparation steps of the composite soil conditioner are basically the same as those in Example 1, except that in Example 4, the amount of calcium lignosulfonate is replaced from 5 parts to 8 parts.
[0059] Example 5
[0060] This embodiment provides a composite soil conditioner and its preparation method. The components and preparation steps of the composite soil conditioner are basically the same as those in Example 1, except that calcium lignosulfonate is replaced with magnesium lignosulfonate in Example 5.
[0061] Comparative Example 1
[0062] This comparative example provides a composite soil conditioner and its preparation method. Its components and preparation steps are basically the same as those in Example 1, except that in Comparative Example 1, potassium ferrous sulfate is replaced with an equal amount of potassium feldspar.
[0063] Comparative Example 2
[0064] This comparative example provides a composite soil conditioner and its preparation method. The components and preparation steps of the composite soil conditioner are basically the same as those in Example 1. The only difference is that in Comparative Example 2, iron humate is replaced with an equal amount of ordinary humic acid.
[0065] Comparative Example 3
[0066] This comparative example provides a composite soil conditioner and its preparation method. The components and preparation steps of the composite soil conditioner are basically the same as those in Example 1, except that calcium lignosulfonate is replaced with an equal amount of methylcellulose in Comparative Example 3.
[0067] Application Example 1
[0068] The composite soil conditioners prepared in Example 1 and Comparative Example 1 were labeled Jar-sc and Ck-sc, respectively. They were applied to ecological restoration in high-altitude permafrost regions. The germination rate of grass seeds after being mixed with Jar-sc and Ck-sc and sown onto the surface of a grass-planting substrate layer in high-altitude permafrost regions under different glue dosage conditions was tested. A blank control was also included. The glue is a gangue-based moisture-retaining polymer, a novel polymer material that can directly bind soil particles and react with clay minerals to form gel-like substances at room temperature. Specifically, glue was added to Jar-sc and Ck-sc, and after mixing with grass seeds, the mixture was sown onto the surface of a grass-planting substrate layer in high-altitude permafrost regions. The observation period was 80 days, and the germination rate of the grass seeds was recorded. The grass seeds included 6 parts of crested wheatgrass, 6 parts of Kentucky bluegrass, 6 parts of cool-field Kentucky bluegrass, and 6 parts of Chinese fescue. The results are as follows: Figure 6 As shown.
[0069] from Figure 6It was found that the germination rate of plants treated with the potassium sulfide alum composite soil conditioner Jar-sc was significantly higher than that of the corresponding grass seeds in the Ck-sc treatment group and the blank control group. Furthermore, the germination rate initially increased and then decreased with increasing glue dosage, reaching 75.41% when the glue dosage was 6.25 g / kg. This indicates that adding glue to the composite soil conditioner can strengthen the bonding between the soil conditioner and organic matter, promoting soil aggregation. Optionally, the mass ratio of glue to potassium sulfide alum composite soil conditioner should be 0.5-1%.
[0070] Physicochemical characteristic test
[0071] The composite soil conditioners prepared in Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2, and 3 were subjected to physicochemical characteristic tests, and the results are shown in Table 1.
[0072] Table 1
[0073]
[0074] As shown in Table 1, in Examples 2 and 3, the contents of organic carbon, total nitrogen, ammoniacal nitrogen, and nitrate nitrogen in the soil all showed an upward trend with the increase of potassium ferric sulfate dosage. The increase in these nitrogen indicators generally indicates improved soil fertility, which is more conducive to plant growth. Examples 1 and 4 show that the increase of calcium lignosulfonate dosage significantly improved soil aggregate structure and subsequently promoted the increase of organic carbon, available phosphorus, and nitrate nitrogen contents. Examples 1 and 5 show no significant differences in key indicators such as organic carbon, total nitrogen, total phosphorus, ammoniacal nitrogen, nitrate nitrogen, and available phosphorus. This indicates that both lignosulfonates can play similar functions in soil conditioners, namely, promoting the formation of soil aggregate structure through cementation and filling effects, thereby enhancing the integrity and strength of the soil.
[0075] As can be seen from Example 1 and Comparative Example 1, compared with potassium feldspar, the addition of potassium ferric sulfate can more effectively increase the content of available potassium, organic carbon, ammonia nitrogen and nitrate nitrogen in the soil conditioner. This indicates that potassium ferric sulfate can effectively enhance the soil's potassium supply capacity, thereby improving soil fertility and creating more favorable conditions for plant growth.
[0076] As can be seen from Example 1 and Comparative Example 2, compared with ordinary humic acid, the addition of humic acid metal complex can promote ion exchange in the soil, indirectly activate phosphorus, and improve the availability and mobility of phosphorus. This process also promotes the accumulation of organic carbon, ammonia nitrogen and nitrate nitrogen, and comprehensively improves the soil's nutrient supply capacity.
[0077] As can be seen from Example 1 and Comparative Example 3, compared with methylcellulose, the addition of lignin sulfonate can cement the soil more effectively, improve soil aggregate structure, and enhance soil fertility.
[0078] Effect verification example
[0079] The composite soil conditioners prepared in Example 1 and Comparative Example 1 were labeled Jar-sc and Ck-sc, respectively, and their effects on vegetation restoration and ecological reconstruction in the permafrost areas of coal gangue mining areas in high-altitude and cold regions were determined. Specifically, a 20-30 cm thick grass-planting substrate layer was laid on the leveled slag surface, and Jar-sc and Ck-sc were evenly spread on the surface of the grass-planting substrate layer. Rotary tillage was carried out at a depth of more than 15 cm using a rotary tillage device to fully mix Jar-sc and Ck-sc with the grass-planting substrate layer and the surface slag. After rotary tillage, the basic formula grass seeds were sown, harrowed and compacted, and covered with non-woven fabric in sequence. Meanwhile, a blank control was set up, specifically including: laying a 20-30cm thick layer of seeding substrate on the leveled slag surface; using a rotary tiller to a depth greater than 15cm to thoroughly mix the seeding substrate layer and the surface slag; and then sequentially sowing the basic formula grass seeds, harrowing and compacting, and covering with non-woven fabric on the tilled surface. The basic formula grass seeds included 6 parts crested wheatgrass, 6 parts Kentucky bluegrass, 6 parts cool-field Kentucky bluegrass, and 6 parts Chinese fescue. The observation period was 90 days, during which the available potassium content in the soil, the average plant height, and the saturated water content in the soil were tested. After 35 days, the germination rate of the grass seeds and the average root-to-shoot ratio of the plants were measured, as shown below. Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown.
[0080] from Figure 1 , Figure 3 , Figure 4 It can be seen that after the application of the compound soil conditioner in Example 1, the soil moisture content remained at 40-50%, the available potassium content reached 284 mg / kg within 60 days, and the grass seed germination rate reached over 70% within 35 days of sowing. Figure 2 and Figure 5 It is evident that the compound soil conditioner in Example 1 resulted in better plant growth after application. This demonstrates that the compound soil conditioner in Example 1 effectively improves the water retention capacity of high-altitude permafrost, enables the slow-release supply of potassium, continuously provides nutrients to plants, and offers a suitable growth environment, thereby significantly improving plant germination rate and growth vigor.
[0081] Advantages of this invention: A composite soil conditioner is produced by combining superphosphate, powdered humic acid, and a metal complex of fulvic acid in a specific ratio to form an acidic activated matrix. Potassium sulfonate minerals are then introduced as a slow-release carrier for potassium fertilizer, and lignin sulfonate is added as a binding and dispersing medium. The mixture is then processed through dry mixing, granulation, and low-temperature curing to create a multifunctional composite conditioner. Potassium sulfonate releases potassium ions continuously through slow hydrolysis in the soil environment. The remaining mineral skeleton after potassium release further synergistically interacts with calcium ions and organic matter in the soil, effectively promoting the formation of water-stable aggregate structures. Therefore, this composite conditioner innovatively achieves the dual synergistic function of slow-release potassium fertilizer and soil aggregate formation. The dynamic transformation process of potassium sulfonate simultaneously solves the problems of potassium supply and soil structure improvement. The low-temperature preparation process ensures the stability of the product in cold environments, and all components can be naturally transformed, making it environmentally friendly and residue-free. Meanwhile, through the slow release and retention of potassium, the soil's potassium supply capacity is effectively enhanced, soil aggregate formation is promoted, and water and fertilizer retention functions are achieved, providing an efficient and reliable overall solution for ecological restoration in high-altitude permafrost regions.
[0082] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A composite soil conditioner, characterized in that, The product comprises the following components in parts by weight: 30-40 parts of superphosphate, 20-25 parts of powdered humic acid, 20-25 parts of fulvic acid metal complex, 10-25 parts of potassium ferrous sulfate and 5-8 parts of lignin sulfonate. The fulvic acid metal complex contains ≥40% fulvic acid, ≥6% metal element content, and has a pH value of 4.0 to 6.
0. The metal element is iron or zinc. The potassium ferrous sulfate has a purity of ≥70% and a particle size of 150-300 mesh.
2. The composite soil conditioner according to claim 1, characterized in that, The lignin sulfonate is one or a combination of calcium lignin sulfonate, sodium lignin sulfonate, magnesium lignin sulfonate, and ammonium lignin sulfonate.
3. The composite soil conditioner according to claim 1, characterized in that, The powdered humic acid has an organic matter content of ≥80%, a humic acid content of ≥65%, and a pH value of 3.5 to 6.
0.
4. The composite soil conditioner according to claim 1, characterized in that, The superphosphate is an acidic, fast-acting phosphate fertilizer with an effective phosphorus content of 12% to 21%.
5. A method for preparing a composite soil conditioner according to any one of claims 1 to 4, characterized in that, Includes the following steps: Superphosphate, powdered humic acid, and fulvic acid metal complex were pulverized, sieved, and mixed to obtain an acid-activated matrix. The acidic activated matrix is dry-mixed with potassium ferrous sulfate and lignin sulfonate, granulated, dried and solidified to obtain a composite soil conditioner.
6. The method for preparing a composite soil conditioner according to claim 5, characterized in that, The drying and curing process includes drying at 50-60°C until the moisture content of the particles is below 8%.
7. The application of a composite soil conditioner according to any one of claims 1-4 in ecological restoration.