A fertilizer for improving saline-alkali soil, and a preparation method and application thereof

Abstract

The application provides a fertilizer for saline-alkali soil clayey hard soil improvement and a preparation method and application thereof, and belongs to the technical field of soil improvement.The application provides a fertilizer for saline-alkali soil clayey hard soil improvement, which comprises the following raw materials: matured cow dung, humic acid ammonium, polymeric ferric sulfate, anionic polyacrylamide, calcium sulfide powder, polyglutamic acid, aminobutyric acid and bacillus subtilis.The fertilizer provided by the application realizes soil desalination and alkali reduction, rapid particle agglomeration, stable formation of granular structure, synchronous improvement of soil nutrient activation and supply, simultaneously improves the soil microbial environment, improves the salt tolerance of crops, achieves the synergistic effect of short-term rapid improvement and long-term fertility maintenance, and is suitable for saline-alkali soil improvement, saline-alkali farmland quality improvement and sustainable agricultural planting in a saline-alkali area.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement technology, specifically relating to a fertilizer for improving clayey compacted soil in saline-alkali land, its preparation method, and its application. Background Technology

[0002] Saline-alkali clay soils, due to their high clay content, low porosity, and abundance of sodium ions and other salt ions, are highly susceptible to the combined harmful effects of compaction and salinization caused by long-term cultivation, improper fertilization, leaching from rainfall, and salt accumulation on the surface. This combination of soil compaction and salinization not only significantly reduces aeration and permeability but also increases soil osmotic pressure, hindering root growth and making water and nutrient absorption difficult. Simultaneously, it reduces microbial activity and degrades soil fertility, ultimately leading to a substantial decline in crop yield and quality. This has become a major bottleneck restricting the high-quality and efficient development of agriculture in saline-alkali areas.

[0003] Currently, technologies for improving clayey compacted soils in saline-alkali land mainly include deep tillage and loosening, straw return to the field, application of organic fertilizers, saline-alkali amendments, and fertilizer conditioning. Among these, applying improved fertilizers is a direct and convenient way to combine soil improvement with nutrient supply. However, existing technologies often suffer from limitations in functionality or synergy: some products focus solely on saline-alkali improvement (such as simply applying desulfurized gypsum to reduce salinity), failing to address compaction; others focus only on aggregate reconstruction (such as simply using flocculants), unable to alleviate the harmful effects of saline-alkali conditions; still others attempt to address both aspects, but suffer from slow decomposition of organic fertilizers, poor short-term improvement effects, and the potential for secondary pollution from improper use of chemical amendments. Furthermore, they lack synergistic design for regulating soil microbial environment, nutrient supply, salinity control, and aggregate reconstruction, resulting in poor sustainability of improvement effects and low crop adaptability. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a functional fertilizer that can achieve "desalination and alkali reduction - rapid aggregation - stable structure - nutrient synergy - microbial activation" in an integrated manner, and simultaneously solve the technical problems of excessive salt content, low efficiency of aggregate structure reconstruction, poor stability, short-lasting improvement effect and poor crop adaptability in saline-alkali clay compacted soil. It has important practical significance and application value.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a fertilizer for improving clayey compacted soil in saline-alkali land, comprising the following raw materials by weight: 30-42 parts of well-rotted cow manure, 8-12 parts of ammonium humate, 18-22 parts of polyferric sulfate, 8-12 parts of anionic polyacrylamide, 18-22 parts of calcium sulfate powder, 0.12-0.18 parts of polyglutamic acid, 0.03-0.07 parts of aminobutyric acid, and 1-3 parts of Bacillus subtilis.

[0006] Preferably, the effective viable count of the Bacillus subtilis is ≥2.0 × 10⁻⁶. 9 CFU / g.

[0007] Preferably, the method for preparing the composted cow manure includes the following steps: composting the cow manure at a high temperature of 55-65°C for 7-10 days.

[0008] The present invention also provides a method for preparing the above-mentioned fertilizer, comprising the following steps: 1. Mixing crushed and sieved well-rotted cow manure, ammonium humate and calcium sulfate powder to obtain a mixture; 2. Mixing the mixture with polyferric sulfate and anionic polyacrylamide, then adding polyglutamic acid and aminobutyric acid and mixing; 3. Spraying an aqueous solution containing Bacillus subtilis, mixing, granulating and drying to obtain the fertilizer.

[0009] Preferably, the mesh size of the sieve is 80 to 100 mesh.

[0010] Preferably, the mixing speed of mixing 1 is 150~200 r / min and the time is 15~20 minutes; the mixing speed of mixing 2 is 150~200 r / min and the time is 20~30 minutes; and the mixing speed of mixing 3 is 300~350 r / min and the time is 10~15 minutes.

[0011] Preferably, an aqueous solution containing Bacillus subtilis is sprayed until the moisture content of the material is 25-30%.

[0012] Preferably, the particle size of the granulated particles is 2-4 mm, the drying temperature is 45-50°C, and the drying is performed until the moisture content is ≤10%.

[0013] The present invention also provides the application of the above-mentioned fertilizer in the improvement of clayey compacted soil in saline-alkali land, wherein the application dosage of the fertilizer is 45~55 kg / mu.

[0014] The present invention also provides a method for increasing the yield of crops planted in saline-alkali clay compacted soil, by applying the above-mentioned fertilizer at a dosage of 45-55 kg / mu, wherein the crops include cotton, rice and sunflower.

[0015] The beneficial effects of this invention are: This invention addresses the shortcomings of existing fertilizers for improving compacted clayey soils in saline-alkali land, including limited improvement effects, inability to simultaneously address both salinity and compaction, poor aggregate structure stability, long improvement cycles, and low crop compatibility. It provides a functional fertilizer for reconstructing the aggregate structure of compacted clayey soils in saline-alkali land, along with its preparation method and application. The fertilizer provided by this invention, through precise proportioning of multiple functional raw materials, achieves soil desalination and alkali reduction, rapid particle aggregation, stable aggregate structure formation, and simultaneous enhancement of soil nutrient activation and supply. It also improves the soil microbial environment and enhances crop salt tolerance, achieving a synergistic effect of rapid short-term improvement and long-term fertility maintenance. It is suitable for improving clayey soils in saline-alkali land, enhancing the quality of saline-alkali farmland, and promoting sustainable agricultural planting in saline-alkali areas. Compared with existing technologies, this invention has the following advantages: 1. Desalination and soil improvement synergistic effect with strong adaptability: Through the synergistic effect of calcium sulfate powder and ammonium humate, desalination and alkali reduction are achieved while reconstructing the aggregate structure, and the salt and alkali damage and compaction problems of clay soil in saline-alkali land are solved at the same time, which greatly improves the adaptability of fertilizer to saline-alkali land.

[0016] 2. Strong stability of granular structure and long-lasting improvement effect: Through the synergistic effect of chemical stabilization (calcium ions, humic acid complex colloid) and biological activation (Bacillus subtilis, polyglutamic acid), the granular structure formed has strong anti-dispersion ability and can be continuously consolidated by microorganisms decomposing organic matter, thus achieving the unity of short-term rapid improvement and long-term fertility maintenance.

[0017] 3. Balanced nutrient supply and high utilization rate: It takes into account the supply of nutrients such as organic matter, nitrogen, calcium, and sulfur. At the same time, through the fertilizer retention effect of polyglutamic acid and the root-promoting effect of aminobutyric acid, it improves the nutrient utilization rate, reduces fertilizer waste, and achieves synergy between soil improvement and crop yield increase.

[0018] 4. Environmentally friendly and highly safe: The raw materials are mainly natural organic matter such as well-rotted cow manure, and the chemical reagents are used in precise and synergistic ways, avoiding secondary soil pollution caused by excessive use of a single chemical amendment; Bacillus subtilis improves the soil micro-ecological environment, reduces pathogen damage, and enhances the safety of agricultural products.

[0019] 5. Simple preparation process and controllable cost: The raw materials are widely available, the preparation process does not require complex equipment, the low-temperature drying process has low energy consumption, it is suitable for large-scale production, and it is easy to promote and apply. Attached Figure Description

[0020] Figure 1 The effects of different fertilizer application rates on soil aggregates.

[0021] Figure 2The effect of different fertilizer application rates on soil salinity is shown in the figure. The left figure shows the pH results, and the right figure shows the electrical conductivity results. Different lowercase letters on the columns indicate p < 0.05, and the same lowercase letter on the columns indicates p > 0.05.

[0022] Figure 3 The effects of different fertilizer application rates on soil organic matter and total nitrogen content are shown in Figure A, where A represents organic matter and B represents total nitrogen. Different lowercase letters on the column indicate p < 0.05, and the same lowercase letter on the column indicates p > 0.05.

[0023] Figure 4 The effect of different carbon sources on organic matter in compacted clay soils is shown. Different lowercase letters on the columns indicate p < 0.05, and the same lowercase letter on the columns indicates p > 0.05.

[0024] Figure 5 The effect of different carbon sources on total nitrogen in compacted clay soils is shown. Different lowercase letters on the columns indicate p < 0.05, and the same lowercase letter on the columns indicates p > 0.05.

[0025] Figure 6 The effects of different treatment groups on soil organic matter content and total nitrogen content are shown. Different lowercase letters on the column indicate p < 0.05, and the same lowercase letter on the column indicates p > 0.05. Detailed Implementation

[0026] This invention provides a fertilizer for improving clayey compacted soil in saline-alkali land, comprising the following raw materials by weight: 30-42 parts of well-rotted cow manure, 8-12 parts of ammonium humate, 18-22 parts of polyferric sulfate, 8-12 parts of anionic polyacrylamide, 18-22 parts of calcium sulfate powder, 0.12-0.18 parts of polyglutamic acid, 0.03-0.07 parts of aminobutyric acid, and 1-3 parts of Bacillus subtilis.

[0027] In the fertilizer of this invention, the roles of each raw material are as follows: Well-rotted cow manure serves as the core organic matter supply carrier, perfectly suited to the needs of improving clayey soils in saline-alkali land. Rich in humus, amino acids, and various minerals, well-rotted cow manure can replenish soil organic matter, reduce the binding force between clay particles to loosen the soil, provide carbon and energy sources for microorganisms with limited activity in saline-alkali land, and simultaneously enhance the soil's water and fertilizer retention capacity, alleviating the problem of "coexistence of drought and nutrient loss" in saline-alkali land.

[0028] Polyferric sulfate is a highly efficient inorganic flocculant and agglomerant that exerts a directional effect on the compaction characteristics of viscous soils. It produces Fe upon ionization in soil aqueous solutions. 3+ It can quickly neutralize the negative charge on the surface of clay particles, disrupt the stable dispersion system of clay particles, promote the collision of clay particles to form primary small aggregates, quickly break the hardened structure, and create aeration and water permeability conditions for subsequent desalination and deep improvement.

[0029] Anionic polyacrylamide is a high-molecular-weight crosslinking stabilizer that can enhance the stability of aggregates. Its long molecular chains can connect multiple primary aggregates through adsorption, forming more stable secondary aggregates; at the same time, its hydrophilic molecular structure can improve the water retention capacity of the aggregates, preventing the aggregates from dispersing and disintegrating during irrigation or rainfall in saline-alkali land, and ensuring the short-term stability of the compaction improvement effect.

[0030] Polyglutamic acid is a saline-alkali adapted fertilizer retention and stress resistance synergist. It has super hydrophilicity and ion adsorption capacity, and can adsorb hundreds of times its own weight of water and nutrients, alleviating the problems of drought and nutrient loss in saline-alkali land. Its molecular functional groups can form a complex system with soil clay and fertilizer nutrients, realizing the slow release of nutrients and improving utilization rate.

[0031] Bacillus subtilis is a microbial agent for improving the microecology and consolidating soil aggregates in saline-alkali land. It can secrete hydrolytic enzymes such as cellulase and protease to efficiently decompose organic matter such as farmyard manure, producing small-molecule organic cementing substances such as humus, which strengthens the aggregate structure. Its metabolites can inhibit the reproduction of pathogens in saline-alkali land, improve the soil microecological environment, enhance soil enzyme activity, promote nutrient cycling, and maintain the improvement effect for a long time. In addition, it can also enhance the toughness of aggregate structure and resist structural damage in saline-alkali environment.

[0032] Ammonium humate is a specialized synergistic component for improving saline-alkali land, possessing dual functions of desalination assistance and nutrient supply. The carboxyl and hydroxyl functional groups in humic acid molecules can preferentially bind with exchangeable sodium ions in the soil, reducing soil alkalinity. At the same time, it fixes free salt ions through adsorption, alleviating saline-alkali stress. Ammonia nitrogen provides crops with readily available nitrogen, solving the nitrogen deficiency problem caused by high osmotic pressure in saline-alkali land crops, and can also activate microbial metabolism, laying the biological foundation for aggregate formation.

[0033] Sulfur-calcium powder is a core component for desalination and alkali reduction in saline-alkali land and a granular stabilizing and enhancing agent. The released calcium ions can react with exchangeable sodium ions in soil colloids to generate easily leached sodium salts, which can achieve desalination and alkali reduction through irrigation. At the same time, calcium ions can promote the coagulation of soil colloids and form stable organic-inorganic composite colloids with humic acid, which can coat the surface of granules and enhance their resistance to salt erosion. Sulfur element supplements essential medium-level elements for crops in saline-alkali land and enhances the crops' resistance to salt stress.

[0034] Gamma-aminobutyric acid (GABA) is a bio-activator specifically designed for saline-alkali land. On the one hand, it promotes crop root growth, enhances the root system's ability to absorb water and fertilizer in high-salt environments, and improves crop salt tolerance; on the other hand, it directionally activates the activity of beneficial microorganisms such as Bacillus subtilis, solving the problem of low microbial activity in saline-alkali land, accelerating the decomposition and transformation of organic matter, and providing bio-power for the long-term stability of aggregate structure.

[0035] In this invention, the preferred amount of well-rotted cow manure is 32-40 parts, more preferably 34-38 parts; the preferred amount of ammonium humate is 9-11 parts, more preferably 10 parts; the preferred amount of polyferric sulfate is 19-21 parts, more preferably 20 parts; the preferred amount of anionic polyacrylamide is 9-11 parts, more preferably 10 parts; the preferred amount of calcium sulfate powder is 19-21 parts, more preferably 20 parts; the preferred amount of polyglutamic acid is 0.14-0.16 parts, more preferably 0.15 parts; the preferred amount of aminobutyric acid is 0.04-0.06 parts, more preferably 0.05 parts; and the preferred amount of Bacillus subtilis is 2 parts. This invention does not have special requirements regarding the specific source of the above raw materials; conventional commercially available products in the field are acceptable. In this invention, the ammonium humate is self-made. A preferred preparation method includes: pulverizing weathered coal to 80-100 mesh, spraying 200 kg / ton of ammonium water (containing 20% ​​ammonium nitrogen), adjusting the moisture content of the weathered coal to 40%, stirring, turning, and covering with a film for ammoniation for 48 hours until the water-soluble humic acid reaches 40% (meeting the ammonium humate standard), thus obtaining ammonium humate. This invention addresses the core pain point of "the combined harm of saline-alkali stress and compaction" in clayey compacted soils of saline-alkali land. Through precise proportioning and functional synergy of various raw materials, a four-in-one aggregate structure reconstruction and enhancement system is constructed, consisting of "directional desalination and alkali reduction - rapid physical aggregation - chemical stabilization and reinforcement - long-term biological consolidation." Each link is interconnected and synergistically amplified. The specific mechanism is as follows: 1. Synergistic Initiation Stage of Targeted Desalination and Rapid Agglomeration: After fertilizer application, the calcium sulfate powder rapidly releases calcium ions, which preferentially react with exchangeable sodium ions in the soil to generate easily leached sodium salts, creating conditions for subsequent irrigation and leaching desalination; simultaneously, the Fe produced by the ionization of polyferric sulfate... 3+ It rapidly neutralizes the negative charge on the surface of clay particles, disrupts the stable system of compacted clay particles, and promotes the rapid aggregation of clay particles to form primary aggregates. Subsequently, anionic polyacrylamide connects the dispersed primary aggregates to form larger aggregates through molecular chain bridging, quickly breaking up soil compaction, improving soil aeration and permeability, and providing channels for desalination ion migration and microbial activity.

[0036] 2. Chemical Composite Stabilization Stage: Based on the formation of aggregates, the calcium ions continuously released by the calcium sulfate powder undergo a complexation reaction with the humic acid functional groups in the ammonium humate to form a stable organic-inorganic composite colloidal film that tightly wraps the surface of the aggregates. On the one hand, this film resists the erosion of salt ions in the saline-alkali environment and prevents the aggregates from dispersing; on the other hand, it further reduces soil cohesion and improves the water stability and stress resistance of the aggregate structure. At the same time, the ammonia nitrogen released by the ammonium humate provides readily available nutrients for microbial metabolism and crop growth, achieving a synergistic effect of "structural stability - nutrient supply".

[0037] 3. Bio-activation and long-term consolidation stage: Well-rotted cow manure (farmyard manure) provides Bacillus subtilis with sufficient carbon and energy. GABA (aminobutyric acid) directionally activates the activity of Bacillus subtilis, enabling it to rapidly multiply in the saline-alkali environment and secrete various hydrolytic enzymes, accelerating the decomposition and transformation of organic matter such as farmyard manure, producing more humic acid, amino acids and other organic cementing substances, further promoting the formation of new aggregates and consolidating the original aggregate structure. Polyglutamic acid, through its super water and fertilizer retention capacity, maintains a suitable water and nutrient environment in the soil, ensuring the continuous activity of microorganisms such as Bacillus subtilis, alleviating drought and nutrient stress on crops in saline-alkali land, and its molecular chains can intertwine with the aggregate structure, enhancing the toughness of the aggregates. In addition, the metabolites of Bacillus subtilis can inhibit the growth of harmful pathogens in saline-alkali land, improve the soil microecology, and provide ecological protection for the long-term stability of aggregate structure and healthy crop growth.

[0038] The entire system achieves the integrated improvement goal of desalination and alkalinity reduction, aggregate reconstruction, and fertility enhancement of clayey compacted soil in saline-alkali land through a synergistic cycle of "desalination paving the way for aggregation, aggregation creating conditions for biological activity, and biological activation consolidating the effects of aggregation and desalination". The functions of each raw material are complementary and their effects are superimposed, avoiding the limitations of single raw material improvement.

[0039] This invention is the first to construct a four-in-one synergistic improvement system integrating "desalination and alkali reduction, physical aggregation, chemical stabilization, and biological activation," precisely addressing the core pain point of "the cumulative harm of salinity and alkali and compaction" in saline-alkali clayey compacted soils. Unlike existing improvement technologies that rely solely on desalination or simple aggregation, this invention achieves simultaneous initiation of desalination and aggregation, and progressive integration of chemical stabilization and biological consolidation, forming a closed-loop improvement process that fills the technological gap in integrated improvement of saline-alkali clayey compacted soils.

[0040] This invention introduces for the first time a synergistic combination of polyglutamic acid and aminobutyric acid, specifically adapted to saline-alkali environments. The synergistic effect of these two compounds enhances the fertilizer's water and fertilizer retention capacity and improves the toughness of its aggregate structure. It also addresses the problems of low activity of beneficial microorganisms and poor crop salt tolerance in saline-alkali soils, achieving a three-dimensional synergy of "soil improvement - microbial activation - crop growth promotion." This breakthrough overcomes the limitations of traditional soil conditioners that only focus on soil structure improvement while neglecting biological compatibility.

[0041] This invention optimizes the raw material ratio scheme to achieve precise functional matching and maximize efficacy. Through experimental screening, the optimal mass ratio of each raw material was determined. Specifically, the ratio of calcium sulfate powder to ammonium humate precisely matches the desalination and alkali reduction requirements of saline-alkali land; the ratio of polyferric sulfate to anionic polyacrylamide balances agglomeration efficiency and structural stability; and the ratio of Bacillus subtilis to farmyard manure and GABA ensures the activity of microorganisms in a saline-alkali environment. This invention solves the technical problems of incomplete desalination, unstable agglomeration, and short-lived improvement effects caused by imbalanced ratios in traditional soil conditioners.

[0042] In this invention, the effective viable count of Bacillus subtilis is preferably ≥2.0 × 10⁻⁶. 9 CFU / g; The preferred method for preparing the composted cow manure includes the following steps: composting the cow manure at high temperature, wherein the high temperature is preferably 55~65℃, more preferably 58~62℃, and the high temperature composting time is preferably 7~10 days, more preferably 8~9 days; The high temperature composting method used in this invention can kill pathogens and weed seeds.

[0043] The present invention also provides a method for preparing the above-mentioned fertilizer, comprising the following steps: 1. Mixing crushed and sieved well-rotted cow manure, ammonium humate and calcium sulfate powder to obtain a mixture; 2. Mixing the mixture with polyferric sulfate and anionic polyacrylamide, then adding polyglutamic acid and aminobutyric acid and mixing; 3. Spraying an aqueous solution containing Bacillus subtilis, mixing, granulating and drying to obtain the fertilizer.

[0044] This invention does not specifically limit the pulverization method; conventional pulverization methods in the art are acceptable. In this invention, the preferred sieve mesh size is 80-100 mesh, the preferred sieve mesh size for the decomposed cow manure is 80 mesh, and the preferred sieve mesh size for the ammonium humate and calcium sulfate powder is 100 mesh. The preferred rotation speed for mixing 1 is 150-200 r / min, more preferably 160-190 r / min, and the preferred time is 15-20 minutes, more preferably 16-19 minutes; the preferred rotation speed for mixing 2 is 150-200 r / min, more preferably 160-180 r / min, and the preferred time is 20-30 minutes, more preferably 22-28 minutes; the preferred rotation speed for mixing 3 is 300-350 r / min, more preferably 320-340 r / min, and the preferred time is 10-15 minutes, more preferably 12-13 minutes. In this invention, the material moisture content is preferably 25-30% after spraying with an aqueous solution containing Bacillus subtilis. This invention does not specify a particular granulation method; any conventional granulator in the art can be used. In this invention, the particle size of the granulated particles is preferably 2-4 mm, the drying temperature is preferably 45-50°C, and the drying is preferably performed until the moisture content is ≤10%.

[0045] The method for preparing fertilizer adapted for saline-alkali land improvement provided by this invention can ensure the activity of core functional components. This invention specifically adopts a low-temperature drying process (45~50℃) to avoid the damage of high temperature to the activity of Bacillus subtilis and the functional structures of polyglutamic acid and GABA. At the same time, through the mixing process of "premixing basic materials (well-rotted cow manure, ammonium humate and calcium sulfate powder) - adding functional components in steps - post-inoculation with microorganisms", it ensures that the components are evenly dispersed and have synergistic effects, thus overcoming the problem of decreased compatibility with saline-alkali land caused by high temperature or uneven mixing in traditional fertilizer preparation processes.

[0046] This invention also provides the application of the above-mentioned fertilizer in the improvement of clayey compacted soil in saline-alkali land, wherein the application dosage of the fertilizer is 45-55 kg / mu. When applying the fertilizer of this invention, it can be directly broadcast and then tilled into the soil, or mixed with other fertilizers and then broadcast. The effect is better when combined with appropriate irrigation after application. In the application described in this invention, the preferred application dosage of the fertilizer is 48-52 kg / mu.

[0047] The present invention also provides a method for increasing the yield of crops planted in saline-alkali clay compacted soil, specifically by applying the above-mentioned fertilizer at a dosage of 45-55 kg / mu, wherein the crops include cotton, rice and sunflower.

[0048] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0049] Unless otherwise specified, the following embodiments are all conventional methods.

[0050] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0051] The ammonium humate in the following examples was prepared in-house. The specific preparation method was as follows: weathered coal was crushed to 100 mesh, and 200 kg / ton of ammonium water (20% ammonium nitrogen) was sprayed on it. The water was sprayed to adjust the moisture content of the weathered coal to 40%. The coal was stirred, turned and spun evenly, covered and sealed for ammoniation for 48 hours until the water-soluble humic acid content reached 40%, thus obtaining ammonium humate. Polyferric sulfate was purchased from Shandong Taihe Water Treatment Technology Co., Ltd., anionic polyacrylamide was purchased from Shandong Baomo Biochemical Co., Ltd., calcium sulfate powder was purchased from Xinjiang Tailu Agricultural Technology Co., Ltd., polyglutamic acid was purchased from Nanjing Kaixuan Biotechnology Co., Ltd., aminobutyric acid was purchased from Shandong Freda Biotechnology Co., Ltd., and Bacillus subtilis was purchased from Shandong Tianfuyuan Biotechnology Co., Ltd.

[0052] Example 1 A fertilizer for improving compacted clayey soil in saline-alkali land is made from the following raw materials: 36 kg of well-rotted cow manure, 11.8 kg of ammonium humate, 20 kg of polyferric sulfate, 10 kg of anionic polyacrylamide, 20 kg of calcium sulfate powder, 0.15 kg of polyglutamic acid, 0.05 kg of aminobutyric acid, and 2 kg of Bacillus subtilis, wherein the effective viable count of Bacillus subtilis is 2.0 × 10⁻⁶. 9 CFU / g.

[0053] The preparation method is as follows: 1. Raw material pretreatment: Place cow manure in a fermentation tank and control the temperature at 60℃ for 8 days to ferment. After fermentation, crush it through an 80-mesh sieve. Crush ammonium humate and calcium sulfate powder through a 100-mesh sieve respectively for later use. 2. Basic material mixing: The pretreated decomposed cow manure, ammonium humate, and calcium sulfate powder are put into a twin-screw mixer and stirred at 180 r / min for 18 minutes to obtain the basic mixture. 3. Addition of functional ingredients: Add polyferric sulfate and anionic polyacrylamide to the base mixture in sequence, and continue mixing at 180 r / min for 25 minutes; then add polyglutamic acid and aminobutyric acid, increase the speed to 320 r / min, and stir for 12 minutes; 4. Microbial inoculation: Spray Bacillus subtilis inoculant (an aqueous solution containing Bacillus subtilis) evenly into the mixture, continue stirring for 10 minutes, and control the moisture content of the material to 28%; 5. Granulation and drying: The uniformly mixed material is fed into a disc granulator to granulate into particles with a diameter of 3mm. Then, it is dried at a low temperature of 48℃ to a moisture content of 8%, cooled, and sieved to obtain the finished fertilizer product.

[0054] Example 2 A fertilizer for improving compacted clayey soil in saline-alkali land is made from the following raw materials: 30 kg of well-rotted cow manure, 8 kg of ammonium humate, 18 kg of polyferric sulfate, 8 kg of anionic polyacrylamide, 18 kg of calcium sulfate powder, 0.12 kg of polyglutamic acid, 0.03 kg of aminobutyric acid, and 1 kg of Bacillus subtilis, wherein the effective viable count of Bacillus subtilis is 2.0 × 10⁻⁶. 10 CFU / g.

[0055] The preparation method is as follows: 1. Raw material pretreatment: Place cow manure in a fermentation tank and control the temperature at 55℃ for 10 days to ferment. After fermentation, crush it through an 80-mesh sieve. Crush ammonium humate and calcium sulfate powder through a 100-mesh sieve respectively for later use. 2. Basic material mixing: The pretreated decomposed cow manure, ammonium humate, and calcium sulfate powder are put into a twin-screw mixer and stirred at 150 r / min for 20 minutes to obtain the basic mixture. 3. Addition of functional ingredients: Add polyferric sulfate and anionic polyacrylamide to the base mixture in sequence, and continue mixing at 150 r / min for 30 minutes; then add polyglutamic acid and aminobutyric acid, increase the speed to 300 r / min, and stir for 15 minutes; 4. Microbial inoculation: Spray Bacillus subtilis inoculant (an aqueous solution containing Bacillus subtilis) evenly into the mixture, continue stirring for 10 minutes, and control the moisture content of the material to 25%; 5. Granulation and drying: The uniformly mixed material is fed into a disc granulator to granulate into particles with a diameter of 2 mm. Then, it is dried at a low temperature of 45°C to a moisture content of 10%. After cooling, it is sieved to obtain the finished fertilizer product.

[0056] Example 3 A fertilizer for improving compacted clayey soil in saline-alkali land is made from the following raw materials: 42 kg of well-rotted cow manure, 12 kg of ammonium humate, 22 kg of polyferric sulfate, 12 kg of anionic polyacrylamide, 22 kg of calcium sulfate powder, 0.18 kg of polyglutamic acid, 0.07 kg of aminobutyric acid, and 3 kg of Bacillus subtilis, wherein the effective viable count of Bacillus subtilis is 2.0 × 10⁻⁶. 9 CFU / g.

[0057] The preparation method is as follows: 1. Raw material pretreatment: Place cow manure in a fermentation tank and control the temperature at 65℃ for 7 days to ferment. After fermentation, crush it through an 80-mesh sieve. Crush ammonium humate and calcium sulfate powder through a 100-mesh sieve respectively for later use. 2. Basic material mixing: The pretreated decomposed cow manure, ammonium humate, and calcium sulfate powder are put into a twin-screw mixer and stirred at 200 r / min for 15 minutes to obtain the basic mixture. 3. Addition of functional ingredients: Add polyferric sulfate and anionic polyacrylamide to the base mixture in sequence, and continue mixing at 200 r / min for 20 minutes; then add polyglutamic acid and aminobutyric acid, increase the speed to 350 r / min, and stir for 10 minutes; 4. Microbial inoculation: Spray Bacillus subtilis inoculant (an aqueous solution containing Bacillus subtilis) evenly into the mixture, continue stirring, and control the moisture content of the material to 30%; 5. Granulation and drying: The uniformly mixed material is fed into a disc granulator to granulate into particles with a diameter of 4 mm. Then, it is dried at a low temperature of 50°C to a moisture content of 10%. After cooling, it is sieved to obtain the finished fertilizer product.

[0058] Experimental Example 1 In April 2025, the physicochemical properties of the tested soil were measured. The soil pH was 8.40, electrical conductivity was 0.98 mS / cm, organic matter content was 10.3 g / kg, total nitrogen content was 0.59 g / kg, available phosphorus content was 15.8 mg / kg, and available potassium content was 127 mg / kg.

[0059] Experimental groups: T1: 50 kg / mu of fertilizer from Example 1 was applied; T2: 100 kg / mu of fertilizer from Example 1 was applied; T3: 150 kg / mu of fertilizer from Example 1 was applied; T4: 200 kg / mu of fertilizer from Example 1 was applied; CK: No fertilizer from Example 1 was applied. The soil conditioner was applied in a single application on April 3, 2025. On July 11, 2025 (cotton bud stage), soil samples from the 0-20 cm soil layer of each treatment were randomly collected using a soil drill for soil chemical property determination.

[0060] The effects of different dosages of the fertilizer described in Example 1 on soil aggregates, soil salinity, soil organic matter and total nitrogen content were tested.

[0061] Soil aggregates were determined using a wet sieving method. The sample was placed on a series of sieves with apertures of 2, 1, 0.5, 0.25, and 0.1 mm from top to bottom, and sieved by shaking for 5 min (30 times / min). Finally, the aggregates from each sieve layer were washed into an aluminum box, dried, and weighed. The mass percentage of aggregates of each particle size was calculated using the following formula: Ai = Gi / MT × 100%, where Ai is the mass percentage (%) of a certain particle size aggregate; Gi is the dried mass (g) of the aggregate of that particle size aggregate; and MT is the total mass (g) of the aggregates.

[0062] Soil pH was determined using the glass electrode method (soil-to-water mass ratio 5:1); soil and deionized water were mixed at a ratio of 1:5, shaken for 0.5 h, filtered, and then measured using a conductivity meter; soil soluble salts were determined using the gravimetric method; organic matter content was determined using the potassium dichromate method; and total nitrogen in the soil was determined using a semi-automatic nitrogen analyzer.

[0063] The results of the test on the effects of different fertilizer dosages on soil aggregates are as follows: Figure 1 As shown, based on soil aggregate size distribution data, compared to the control (CK), treatments T1, T2, T3, and T4 all increased the content of aggregates >1 mm (>2 mm, 2–1 mm) while decreasing the proportion of microaggregates 0.25–0.1 mm. Among these, treatment T4 showed the highest content of aggregates >2 mm and 2–1 mm, indicating the most significant effect in promoting aggregate formation. The CK treatment had a significantly higher content of 0.25–0.1 mm microaggregates, indicating greater aggregate fragmentation and a higher proportion of fine particles under control conditions. These results demonstrate that various regulatory measures can promote the cementation of microaggregates into large aggregates, optimizing soil aggregate structure; different treatments showed varying improvement effects, with treatment T4 exhibiting the best effect in constructing a good soil aggregate structure.

[0064] The effects of different fertilizer application rates on soil salinity, such as Figure 2 As shown, the results regarding the effect on pH are shown in [the original text]. Figure 2As shown in the left figure, there were no significant differences between the CK, T1, and T2 treatments (p>0.05). Compared to CK, soil pH values ​​in treatments T1, T2, T3, and T4 all showed a decreasing trend. Specifically, soil pH decreased by 2.28% in treatment T1, 3.26% in treatment T2, 8.16% in treatment T3, and 7.77% in treatment T4. Among the different fertilizer application rates, soil pH values ​​in treatments T3 and T4 were significantly lower than the other treatments (p<0.05), with the most significant decrease observed in treatment T3, which decreased by 8.16% compared to CK. Soil electrical conductivity also showed a significant decreasing trend compared to CK with different amounts of soil conditioner (see [reference needed]). Figure 2 (See the right figure). The soil electrical conductivity of treatment T1 decreased by 68.54% compared to the control (CK), treatment T2 decreased by 74.09%, treatment T3 decreased by 4.43%, and treatment T4 decreased by 50.17%. Compared to the control, treatment T2 showed the largest decrease in soil electrical conductivity (0.789 mS / cm), while treatment T3 showed the smallest decrease (2.91 mS / cm).

[0065] The effects of different fertilizer application rates on soil organic matter and total nitrogen content, such as Figure 3 As shown, the soil organic matter and total nitrogen content of different fertilizer application rates were significantly higher than those of the control (CK) treatment. Figure 3 As shown in A, compared with the control (CK), the soil organic matter content of treatments T1, T2, T3, and T4 increased by 45.32%, 85.09%, 59.65%, and 103.51%, respectively; treatment T4 had the highest soil organic matter content, at 23.2 g / kg. Figure 3 As shown in B, compared with CK, the total nitrogen content of soil in treatments T1, T2, T3, and T4 increased by 49.35%, 67.53%, 32.04%, and 99.13%, respectively; among them, treatment T4 had the highest total nitrogen content, at 1.53 g / kg.

[0066] Experimental Example 2 In 2023 and 2024, this invention compared the well-rotted cow manure from Example 1 with four other fertilizers: biochar (purchased from Suihua Lusen Charcoal Powder Technology Co., Ltd., with a diameter of 0.5~5 mm), bio-fertilizer (purchased from Leibangs Biotechnology (Beijing) Co., Ltd.), commercial organic fertilizer (purchased from Xinjiang Minfu Biotechnology Co., Ltd.), and mineral-derived potassium humate (purchased from Xinjiang Minfu Biotechnology Co., Ltd.). Three gradients were set for each fertilizer.

[0067] The experimental site was located in Dunkuotan Town, Kuqa City, Aksu Prefecture. The physicochemical properties of the tested soil were measured in March 2023. The soil contained 25.56% clay, 29.97% silt, and 44.47% sand. The organic matter content was 11.30 g / kg, the total nitrogen content was 0.30 g / kg, the soil moisture content was 16%, and the soil volumetric mass was 1.50 g / cm³. 3 The hydrolyzable nitrogen content was 31.20 mg / kg, the available phosphorus content was 16.40 mg / kg, the available potassium content was 235 mg / kg, the water-soluble salt content was 11.40 g / kg, and the pH was 8.9. A split-plot block design was used. Five carbon source treatments were set up: farmyard manure (composted cow manure from Example 1), biochar, bio-fertilizer, commercial organic fertilizer, and potassium humate (treatments in 2023 were designated Y1, Y2, Y3, Y4, and Y5 respectively; treatments in 2024 were designated YS1, YS2, YS3, YS4, and YS5 respectively). Each group had three gradient treatments: 50% of the recommended amount (-1), 100% of the recommended amount (-2), and 150% of the recommended amount (-3). The control group (CK) was not treated with any carbon source. Each treatment was replicated three times. The application rates of carbon sources for each treatment are detailed in Table 1. The 100% recommended rate was based on surveys of local farmers and literature reviews. Two gradients were established based on the recommended rates: 50% and 150%. The experimental plot size was 5 m × 6 m, with an area of ​​30 m². 2 Cotton was sown on April 10, 2023, and cotton was sown on April 15, 2024. Carbon source materials were applied in a single application on April 5, 2023. Subsequent management and fertilization in the experimental area were carried out by farmers according to their previous farmland management experience to ensure cotton emergence rate. Organic matter and total nitrogen content were measured in different groups at the seedling, boll-forming, and lint-opening stages. Specific testing methods were the same as in Experiment 1.

[0068] Table 1. Application amount of carbon source for different treatments

[0069] The results are as follows Figure 4 and Figure 5 As shown. By Figure 4It can be seen that the soil organic matter content increases with the input of different carbon sources and the increase in the amount of different carbon sources applied. The soil organic matter content during the cotton growing season in 2023 and 2024 showed a gradual upward trend. In the seedling stage of 2023, compared with the control (CK) treatment, all treatments increased the soil organic matter content. Among them, the Y1-3 treatment (150% of the recommended amount of farmyard manure) had the largest increase, at 11.1 g / kg, reaching 11.00%. During the flowering and boll-forming stage, the soil organic matter content of all five carbon sources at 150% of the recommended amount was higher than that of the CK treatment, increasing by 12.69%, 9.08%, 9.92%, 10.50%, and 11.35% respectively. During the boll opening stage, as the growth period progressed, the soil organic matter content in each treatment continued to increase, reaching its highest level throughout the entire growth period. The 150% recommended amount in each group was significantly higher than that in the CK treatment. Among them, the Y1-3 treatment (150% recommended amount of farmyard manure) in the farmyard manure group had the largest increase in organic matter content, reaching 11.11%, with an organic matter content of 11.31 g / kg.

[0070] In 2024, the soil organic matter content of each treatment continued to increase throughout the cotton growth period compared with 2023, but did not reach a significant level. During the cotton seedling stage, boll-forming stage, and boll-opening stage, the soil organic matter content of the YS1-3 treatment (150% of the recommended amount of farmyard manure) in the farmyard manure group was 11.34 g / kg, 11.41 g / kg, and 11.48 g / kg, respectively, which were 11.69%, 10.16%, and 10.47% higher than the CK treatment, respectively.

[0071] Depend on Figure 5 It can be seen that the average soil total nitrogen content at different cotton growth stages in 2023 and 2024 was, in descending order, that of the boll-opening stage, flowering and boll-forming stage, and seedling stage. Soil total nitrogen content increased with the input and application rate of different carbon sources. The effects of different carbon source inputs on soil total nitrogen content during the cotton growth stages were, in descending order, biochar, farmyard manure, bio-fertilizer, commercial organic fertilizer, and potassium humate. Furthermore, the total nitrogen content of each treatment was higher than that of the control (CK) treatment at different cotton growth stages. In 2023, the total nitrogen content of treatment Y1-3 (150% of the recommended amount of farmyard manure) in the farmyard manure group was 0.63 g / kg, 0.61 g / kg, and 0.59 g / kg, respectively, significantly higher than other treatments, increasing by 5.59%, 5.98%, and 9.57% compared to the CK treatment.

[0072] In 2024, at different growth stages of cotton, the total nitrogen content of the YS1-3 treatment (150% of the recommended amount of farmyard manure) in the farmyard manure group was 0.61 g / kg, 0.64 g / kg, and 0.71 g / kg, respectively, which was significantly higher than other treatments, and increased by 6.03%, 6.58%, and 7.57% compared with the CK treatment.

[0073] Experimental Example 3 Experimental Groups: Treatment 1: The difference from Example 1 is that the amount of anionic polyacrylamide added is 10%, and Bacillus subtilis and polyferric sulfate are not added. All other aspects are the same as in Example 1.

[0074] Treatment 2: The difference from Example 1 is that the amount of Bacillus subtilis added is 2%, and anionic polyacrylamide and polyferric sulfate are not added. All other aspects are the same as in Example 1.

[0075] Treatment 3: The difference from Example 1 is that the amount of polyferric sulfate added is 20%, and anionic polyacrylamide and Bacillus subtilis are not added. All other aspects are the same as in Example 1.

[0076] Treatment 4: The difference from Example 1 is that the amount of Bacillus subtilis added is 2%, the amount of anionic polyacrylamide added is 10%, and polyferric sulfate is not added. All other aspects are the same as in Example 1.

[0077] Treatment 5: The difference from Example 1 is that the amount of anionic polyacrylamide added is 10%, the amount of polyferric sulfate added is 20%, and Bacillus subtilis is not added. All other aspects are the same as in Example 1.

[0078] Treatment 6: The difference from Example 1 is that the amount of Bacillus subtilis added is 2%, the amount of polyferric sulfate added is 20%, and anionic polyacrylamide is not added. All other aspects are the same as in Example 1.

[0079] Treatment 7: The difference from Example 1 is that the amount of polyacrylamide added is 10%, the amount of Bacillus subtilis added is 2%, and the amount of polyferric sulfate added is 20%, while the rest are the same as in Example 1.

[0080] Treatment 8: CK treatment, without adding any modifiers.

[0081] The tested soil contained 26.73% clay, 30.11% silt, and 43.16% sand. The organic matter content was 10.27 g / kg, the total nitrogen content was 0.28 g / kg, the soil moisture content was 15%, and the soil volumetric mass was 1.50 g / cm³. 3The hydrolyzable nitrogen content is 30.77 mg / kg, the available phosphorus content is 16.58 mg / kg, the available potassium content is 246 mg / kg, the water-soluble salt content is 10.29 g / kg, and the pH is 8.5.

[0082] Soil incubation was conducted in an artificial climate chamber on August 1, 2024, using an 8.75L (350mm×250mm×100mm) test chamber. Eight treatments were designed: 1. 10% polyacrylamide, 2. 2% Bacillus subtilis, 3. 20% polyferric sulfate, 4. 2% Bacillus subtilis + 10% polyacrylamide, 5. 10% polyacrylamide + 20% polyferric sulfate, 6. 2% Bacillus subtilis + 20% polyferric sulfate, 7. 10% polyacrylamide + 0.2% Bacillus subtilis + 20% polyferric sulfate, and 8. CK (no amendments). Each treatment was replicated three times. All amendments were dissolved and added to the soil during the first watering. Water was added weekly during the experiment to maintain soil moisture content at approximately 60% of maximum field capacity (50%), i.e., approximately 30%. Soil samples were collected three times at the end of August, September and October, and the soil organic matter content, total nitrogen content and soil particle size distribution were tested.

[0083] The effects of different treatment groups on soil organic matter content, total nitrogen content, and soil particle size distribution were investigated. Membership function transformation was performed on the raw measured data of each soil indicator. Indicators were categorized into positive and negative indicators based on their ecological effects. A linear range membership function was used to normalize the measured values ​​to a membership degree of 0-1. A membership degree closer to 1 indicates a better indicator trait. Positive indicators: Fi = (Xi - Xmin) / (Xmax - Xmin); Negative indicators: Fi = (Xmax - Xi) / (Xmax - Xmin), where: Fi is the membership function value; Xi is the measured value of the indicator; Xmax and Xmin are the maximum and minimum values ​​of the indicator across all treatments, respectively. The weighted arithmetic mean of the membership function values ​​of each indicator was calculated to obtain the comprehensive evaluation value of soil improvement. The soil was then ranked according to the magnitude of the comprehensive evaluation value.

[0084] The results are as follows Figure 6 As shown in Table 2, treatments 1 and 2 had higher organic matter and total nitrogen contents in the first sampling. In the second sampling, treatment 7 had the highest organic matter and total nitrogen contents. In the third sampling, these contents decreased. With time, the number of particles <0.002 mm gradually decreased in the soil particle size distribution. Overall, the results indicate that the effects of different amendment combinations on improving soil physicochemical properties varied among the eight amendment combinations. Treatment 7 showed the best effect in improving soil physicochemical properties among the eight amendment combinations.

[0085] Table 2. Comprehensive Evaluation Analysis Results

[0086] Test Example 4 Test location: Kuqa County Test Area The physicochemical properties of the tested soil were determined in March 2023. The soil contained 25.56% clay, 29.97% silt, and 44.47% sand. The organic matter content was 11.30 g / kg, the total nitrogen content was 0.30 g / kg, the soil moisture content was 16%, the soil volumetric mass was 1.50 g / cm3, the hydrolyzable nitrogen content was 31.20 mg / kg, the available phosphorus content was 16.40 mg / kg, the available potassium content was 235 mg / kg, the water-soluble salt content was 11.40 g / kg, and the pH was 8.9.

[0087] Experimental groups: 4 groups were set up, each with an area of ​​50m². 2 Repeat 3 times, with cotton as the crop.

[0088] Control group: Conventional fertilization (200 kg / mu of well-rotted farmyard manure + 20 kg / mu of urea); Experimental group: The fertilizer obtained in Example 1 of this invention was applied: CK=0 kg / mu, T1=50 kg / mu, T2=100 kg / mu, T3=200 kg / mu, T4=400 kg / mu.

[0089] Experimental period: the entire growth period of cotton (210 days).

[0090] The results of soil physicochemical property improvement showed that with the increase of fertilizer, pH decreased by 2.28%-8.16% compared with CK treatment (8.13), electrical conductivity decreased by 50%-74.09% compared with CK treatment (2.64 mS / cm), organic matter increased by 45%-103.51% compared with CK treatment (11.4 g / kg), total nitrogen increased by 40%-99.13% compared with CK treatment (0.77 g / kg), available phosphorus increased by 55.54%-91.22% compared with CK treatment (21.87 mg / kg), and available potassium increased by 23.78%-86.44% compared with CK treatment (150 mg / kg).

[0091] Table 3 shows the crop growth and yield results. With increasing application rate, plant height also increased by 53.3%-67.0%, stem diameter increased by over 11.2%, and chlorophyll content increased by 3.5%-17.3%. The number of bolls increased by the most, up to 13.49%; there was no significant difference in boll weight among different groups, but the increase reached 4.6%; cotton yield increased by 9.8%, 9.3%, 10.4%, and 27.8%, respectively.

[0092] Table 3. Effects of different groups on cotton growth

[0093] Benefit analysis: As shown above, the fertilizer input of this invention has a linear positive correlation with the increase in yield, and the effect of input on increasing yield is significant; however, the input-output efficiency is negatively correlated, with only an input of 50 kg / mu resulting in an additional income of 86.4 yuan / mu, indicating that an additional application of 50 kg can achieve the purpose of improving efficiency.

[0094] Based on the above experimental results, the fertilizer of this invention can rapidly improve the physical and chemical properties of clayey compacted soil, form a stable granular structure, and significantly increase crop yield. Applying an additional 50 kg per mu can achieve the purpose of improving efficiency.

[0095] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A fertilizer for improving compacted clayey soil in saline-alkali land, characterized in that, The ingredients include the following raw materials by weight: 30-42 parts of well-rotted cow manure, 8-12 parts of ammonium humate, 18-22 parts of polyferric sulfate, 8-12 parts of anionic polyacrylamide, 18-22 parts of calcium sulfate powder, 0.12-0.18 parts of polyglutamic acid, 0.03-0.07 parts of aminobutyric acid, and 1-3 parts of Bacillus subtilis.

2. The fertilizer according to claim 1, characterized in that, The effective viable count of the Bacillus subtilis is ≥2.0 × 10⁻⁶. 9 CFU / g.

3. The fertilizer according to claim 1, characterized in that, The method for preparing the decomposed cow manure includes the following steps: the cow manure is decomposed at high temperature, the temperature of which is 55~65℃, and the decomposition time is 7~10 days.

4. The method for preparing the fertilizer according to any one of claims 1 to 3, characterized in that, The process includes the following steps:

1. Mixing crushed and sieved well-rotted cow manure, ammonium humate, and calcium sulfate powder to obtain a mixture; 2. Mixing the mixture with polyferric sulfate and anionic polyacrylamide, then adding polyglutamic acid and aminobutyric acid and mixing; 3. Spraying an aqueous solution containing Bacillus subtilis, mixing, granulating, and drying to obtain the fertilizer.

5. The preparation method according to claim 4, characterized in that, The sieve mesh size includes 80 to 100 mesh.

6. The preparation method according to claim 4, characterized in that, The mixing speed of mixing 1 is 150~200 r / min, and the time is 15~20 minutes; the mixing speed of mixing 2 is 150~200 r / min, and the time is 20~30 minutes; the mixing speed of mixing 3 is 300~350 r / min, and the time is 10~15 minutes.

7. The preparation method according to claim 4, characterized in that, Spray an aqueous solution containing Bacillus subtilis until the moisture content of the material is 25-30%.

8. The preparation method according to claim 4, characterized in that, The granulation particle size is 2~4mm, the drying temperature is 45~50℃, and the drying is carried out until the moisture content is ≤10%.

9. The application of the fertilizer according to any one of claims 1 to 3 in the improvement of clayey compacted soil in saline-alkali land, characterized in that, The application rate of the fertilizer is 45-55 kg / mu.

10. A method for increasing crop yield in saline-alkali clayey compacted soil, characterized in that, The fertilizer according to any one of claims 1 to 3 is applied at a dosage of 45 to 55 kg / mu, and the crop includes cotton, rice and sunflower.

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