Stable fertilizer with growth promoting and stress resisting functions and preparation method thereof

Abstract

The invention discloses a stable fertilizer with growth-promoting and stress-resisting functions as well as a preparation method and application of the stable fertilizer. The fertilizer comprises the following raw materials in parts by weight: 10 parts of an inorganic nutrient component; 20 parts and 15 parts of a functional compound microbial agent; 25 parts of the microbial active accelerant A; 3 parts of a microbial activity promoter B; 2 parts and 30 parts of a decomposed organic matter carrier; 40 parts of water-retaining agent, and 1 part of water-retaining agent; 3 parts of a pH buffer agent; and 4 parts. The functional compound microbial agent comprises monascus xerophilus, halotolerant bacillus flavus and paenibacillus limonellii, the functions of the monascus xerophilus, the halotolerant bacillus flavus and the paenibacillus limonellii are complementary, and the metabolic activity of strains is remarkably enhanced by combining active promoters (trehalose / chitosan oligosaccharide and L-and fucose / vitamin B7). The fertilizer provided by the invention can effectively improve the soil structure, enhance the tolerance of wheat to adverse situations such as drought, salt and alkali, and improve the yield and quality, and is suitable for wheat planting in arid, semi-arid and saline-alkali soil.

Description

Technical Field

[0001] This invention belongs to the field of organic and microbial fertilizer technology, specifically relating to a stable fertilizer with growth-promoting and stress-resistant functions and its preparation method. Background Technology

[0002] As one of the world's three major food crops, wheat yield stability is significantly affected by drought stress. Especially in arid and semi-arid regions of northern China, water scarcity has become a key factor restricting high and stable wheat yields. Long-term application of traditional chemical fertilizers not only leads to soil compaction and low fertilizer efficiency but also exacerbates crop sensitivity to adverse conditions. Furthermore, factors such as phosphorus deficiency in the soil, drought, and frequent soil-borne diseases hinder sustainable agricultural development and environmental security. Therefore, the rational and efficient use of land resources with yield-impeding characteristics, thereby ensuring the sustainable use of land resources, is of significant strategic importance for ecological environment construction and the development of reserve arable land resources.

[0003] Bio-organic fertilizer is a type of fertilizer that combines organic matter with beneficial microorganisms. Through microbial activity, it improves the soil environment and promotes plant growth. Currently, bio-organic fertilizers are mostly made from agricultural waste such as livestock and poultry manure and straw, with the addition of functional microorganisms such as nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, and potassium-solubilizing bacteria. While these fertilizers can improve soil fertility to some extent, their effects on stress resistance, plant growth promotion, and soil stability enhancement are limited.

[0004] Stress resistance and growth promotion refer to enhancing a plant's tolerance to adverse conditions and promoting its growth through biological or chemical means. Current technologies primarily achieve this by adding plant growth regulators (such as gibberellins and abscisic acid) or functional fertilizers. However, these methods suffer from high costs, inconsistent effectiveness, and environmental unfriendliness.

[0005] Rhizosphere microorganisms, especially PGPR, play an important role in plant healthy development and tolerance to abiotic stress, and have good application potential. Therefore, exploring rhizosphere microorganisms with beneficial drought-resistant functions and improving crop root vitality and resistance to drought, phosphorus deficiency, salinity and alkalinity from the perspective of regulating rhizosphere plant microorganisms will provide an effective way to improve soil fertility, prevent diseases and increase yields in an eco-friendly manner.

[0006] However, current microbial fertilizers generally suffer from problems such as limited functionality and poor environmental adaptability, making it difficult to sustain their growth-promoting and stress-resistance effects in complex and variable soil environments. Furthermore, most strains have low survival rates under abiotic stresses such as drought and high temperatures, leading to unstable fertilizer efficacy.

[0007] For example, Chinese patent application CN202310676157.5 discloses a drought-resistant organic fertilizer and its preparation method, belonging to the field of organic fertilizer technology, which includes the following raw materials in parts by weight: animal manure, straw, bran, water-retaining agent, microbial agent, humic acid, biochar, and trace elements. The preparation method includes the following steps: (1) mixing animal manure, straw, bran, and microbial agent and then carrying out anaerobic fermentation, and then adding water-retaining agent to adjust the moisture content to obtain anaerobic fermentation product; (2) mixing the anaerobic fermentation product, humic acid, trace elements, and modified biochar evenly and then granulating to obtain the drought-resistant organic fertilizer.

[0008] For example, Chinese patent application CN202010855744.7 provides a compound microbial fertilizer with drought and pest resistance and its preparation method, which relates to the field of microbial fertilizer. This compound microbial fertilizer, which is drought-resistant and pest-resistant, includes organic fertilizer, microbial strains, and inorganic nutrient raw materials. The organic fertilizer is composed of a mixture of pig manure and crop straw. The microbial strains are Bacillus, silicate bacteria, and rhizobium, and the ratio is 1:0.5:1. The weight ratio of each component of the organic fertilizer and microbial strains is 70-90 parts of the pig manure and crop straw mixture and 5-8 parts of the microbial strains. The weight ratio of each component of the inorganic nutrient raw materials is 0.25-0.5 parts of borax, 0.05-0.15 parts of zinc sulfate, 0.15-0.3 parts of calcium carbonate, 0.2-0.4 parts of ammonium phosphate, 0.05-0.15 parts of potassium chloride, 0.01-0.02 parts of manganese sulfate, 0.1-0.3 parts of potassium sulfate, 0.01-0.03 parts of copper sulfate, 0.02-0.04 parts of titanium dioxide, and 0.2-0.35 parts of sodium molybdate. The use of Bacillus, silicate bacteria and rhizobium significantly improves fertilizer utilization and has the effects of disease and insect prevention and drought resistance.

[0009] Although the above technologies have made some breakthroughs in drought resistance and multifunctionality, the efficiency of their microbial community is still limited by the dynamic changes in the soil microenvironment, resulting in large fluctuations in the effect in practical applications, making it difficult to achieve long-term colonization and functional expression of the microbial agent in the rhizosphere. Summary of the Invention

[0010] This invention addresses the problems of existing microbial fertilizers, such as limited functionality, weak environmental adaptability, poor synergy between stress resistance and growth promotion, and unstable fertilizer efficacy. It provides a stable fertilizer with growth-promoting and stress-resistance functions, along with its preparation method. This fertilizer achieves a synergistic effect of "microbial growth promotion – water and fertilizer retention by the carrier – enhanced activity by the regulator" through screening specific stress-resistant strains and optimizing the organic matter carrier and activity promoter. This significantly improves crop tolerance to drought, phosphorus deficiency, and salinity, while also improving soil physicochemical properties and increasing fertilizer utilization, providing technical support for sustainable agricultural development.

[0011] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 10-20 parts inorganic nutrient components, 15-25 parts functional compound microbial agent, 0.5-3 parts microbial activity promoter A, 1-2 parts microbial activity promoter B, 30-40 parts decomposed organic matter carrier, 1-3 parts water-retaining agent, and 2-4 parts pH buffer.

[0012] Furthermore, the inorganic nutrient components include nitrogen, phosphorus, and potassium, with a mass ratio of N:P2O5:K2O = 15-20:10-15:10-15.

[0013] Furthermore, the functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Haemophilus flavonoids* strain has the accession number CGMCC No. 1.12756, with an original accession date of December 30, 2013; and the *Bacillus lijrens* strain has the accession number CGMCC No. 1.10239, with an original accession date of October 16, 2009. All three strains can be purchased from the preservation center and do not require biological preservation.

[0014] Furthermore, the microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of (1:1) to (5:1).

[0015] Furthermore, the microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of (2:1) to (10:1).

[0016] Furthermore, the preparation method of the composted organic matter carrier is as follows: livestock and poultry manure and straw are mixed at a mass ratio of 3:1, fermentation inoculants are added, and composting is carried out under ventilated conditions for 30-45 days until the material is fully composted, odorless, with a total nutrient content ≥5% and an organic matter content ≥30%; the fermentation inoculant is composed of Bacillus subtilis, Bacillus licheniformis and EM bacteria mixed at a live bacteria ratio of 1:1:2, and the inoculation amount is 0.3%-0.5%.

[0017] Furthermore, the water-retaining agent is sodium polyacrylate; the pH buffer is a mixture of potassium dihydrogen phosphate and calcium carbonate in a weight ratio of 3:1.

[0018] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus purpureus, Halobacillus flavus, and Bacillus listiformis were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed culture for each strain; the composition of the seed tank culture medium was: glucose 20g / L, yeast extract 10g / L, ammonium sulfate 5g / L, potassium dihydrogen phosphate 2g / L, magnesium sulfate 1.5g / L, and natural pH.

[0019] (4) Mixed fermentation: The seed cultures of *Monascus purpureus*, *Haemophilus spp.*, and *Bacillus lignosticus* were mixed at a volume ratio of 3:2:1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid-state fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid-state fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated by extrusion granulation process to produce granules with a particle size of 2-4 mm. The granules are then dried until the moisture content is ≤8% to obtain a stable fertilizer with growth-promoting and stress-resistant functions.

[0020] Furthermore, in step (2), the activation medium for *Monascus xerophyticus* is malt extract medium with a natural pH and a culture temperature of 25-27℃; the activation medium for *Haloxybacterium flavonoids* is LB medium with a pH of 7.0-7.2 and a culture temperature of 28-30℃; and the activation medium for *Bacillus lijrens* is NA medium with a pH of 7.0-7.5 and a culture temperature of 28-30℃.

[0021] Application of a stable fertilizer with growth-promoting and stress-resistance functions in improving soil structure, promoting wheat growth, and enhancing wheat's drought and salt tolerance.

[0022] All raw materials used in this application are commercially available.

[0023] The stable fertilizer with growth-promoting and stress-resistant functions and its preparation method provided by this invention have the following significant beneficial effects: 1. Synergistic effects and complementary functions of multiple bacteria significantly enhance growth promotion and stress resistance: The three functional bacteria selected in this invention—*Monascus purpureus*, *Haloxybacterium halophilum*, and *Bacillus listiformis*—all possess clear growth promotion and stress resistance functions, and their functions are complementary. *Monascus purpureus* can still grow stably under drought stress and secrete a variety of plant growth-promoting substances (such as hormone-like substances), directly stimulating wheat root development and plant growth; *Haloxybacterium halophilum* has excellent salt and alkali tolerance and can improve wheat's adaptability to salt and alkali stress by regulating plant osmotic pressure and enhancing the antioxidant system; *Bacillus listiformis* has efficient phosphorus solubilization and nitrogen fixation capabilities and can synthesize plant hormones (such as IAA), further promoting nutrient absorption and growth. After the three bacteria are combined, they not only exert their core functions individually, but also form a synergistic growth promotion and stress resistance network effect through the interaction of metabolites, significantly improving the growth potential and yield of wheat under drought, salt and alkali and other adverse conditions.

[0024] 2. The two microbial activity promoters specially added in this invention have clear synergistic protective and activating effects: Microbial activity promoter A (trehalose and chitosan oligosaccharide combination): Trehalose, as a protectant, can stabilize the cell membrane structure and enhance the strain's tolerance to adverse conditions such as drought and high temperature; chitosan oligosaccharide, as an elicitor, can induce plant systemic resistance and promote the colonization of the strain in the rhizosphere. Microbial activity promoter B (L-fucose and vitamin B7 combination): L-fucose can serve as a carbon source and signaling molecule for specific strains, promoting their proliferation and metabolism; vitamin B7 (biotin) is an important component of many coenzymes and directly participates in cell energy metabolism and growth. In particular, both L-fucose and vitamin B7 (biotin) are indispensable. Activity promoters A and B not only provide nutrition and protection for functional bacteria but also activate their metabolic pathways, enhancing their survival rate and functional expression stability in the soil.

[0025] 3. Improve soil structure and enhance soil fertility: The introduction of decomposed organic matter carriers not only provides carbon and energy sources for microorganisms, but its rich organic matter content also significantly improves soil aggregate structure, increases soil porosity, and enhances soil water and fertilizer retention capacity and aeration. Combined with the use of water-retaining agents (sodium polyacrylate), it can further enhance the soil's water-holding capacity under drought conditions. pH buffers (a mixture of potassium dihydrogen phosphate and calcium carbonate) can stabilize soil pH, creating a suitable acid-base environment for crop growth and microbial activity. Long-term application can effectively alleviate soil compaction, improve soil fertility, and promote a virtuous cycle in the soil ecosystem.

[0026] 4. Balanced Nutrient Supply: This invention scientifically combines inorganic nutrient components, organic carriers, and functional microbial agents to achieve a rapid supply of inorganic nutrients with a slow-release and long-lasting effect of organic nutrients and microbially activated nutrients. The inorganic nutrient components provide the macronutrients such as nitrogen, phosphorus, and potassium required for crop growth, while the functional microbial agents activate insoluble nutrients in the soil (such as phosphorus) through their life activities, improving nutrient utilization and reducing fertilizer runoff and environmental pollution. This synergistic effect makes fertilizer nutrient supply more balanced and efficient, meeting the requirements of modern agricultural sustainable development.

[0027] 5. Scientific and rational preparation process, stable product quality: The preparation method of this invention has a clear process flow and is highly operable. From the preparation of the mature organic matter carrier, the activation and expansion culture of the strain, to the solid-state fermentation of the compound microbial agent, and finally to the mixing, granulation and drying of the fertilizer, the parameters of each step are clear and the conditions are controllable. In particular, the precise control of temperature, humidity and turning frequency during solid-state fermentation ensures the efficient proliferation of functional bacteria and the accumulation of metabolites. The granulation process gives the product a suitable particle size and good physical properties, facilitating storage, transportation and application. Drying to a moisture content of ≤8% ensures the stability of the product during storage and effectively prevents clumping and nutrient loss.

[0028] 6. Significant Application Effects and High Promotion Value: The stabilized fertilizer of this invention demonstrates outstanding effects in improving soil structure, promoting wheat growth, and enhancing wheat's drought and salt tolerance. It is not only suitable for normal soil conditions but also plays a vital role in arid, semi-arid, and saline-alkali soils, making it significant for developing and utilizing low- and medium-yield farmland and ensuring food security. Furthermore, the raw materials are widely available, the preparation cost is controllable, and it offers good economic and ecological benefits, making it easy to produce and promote on a large scale. Attached Figure Description

[0029] Figure 1 The image shows the antagonistic effect of *Monascus purpureus*, *Halobacterium fluorescens*, and *Bacillus listerius* in the present invention, where 1 represents *Monascus purpureus*, 2 represents *Halobacterium fluorescens*, and 3 represents *Bacillus listerius*. Figure 2The data included temperature, precipitation, and sunshine variations during the wheat growing season in the experimental field. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0031] Example 1 A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 10 parts inorganic nutrient components, 15 parts functional compound microbial agent, 0.5 parts microbial activity promoter A, 1 part microbial activity promoter B, 30 parts decomposed organic matter carrier, 1 part water-retaining agent, and 2 parts pH buffer.

[0032] The inorganic nutrient components include nitrogen, phosphorus, and potassium, with a mass ratio of N:P2O5:K2O=15:10:10.

[0033] The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Haemophilus flavonoids* strain has the accession number CGMCC No. 1.12756, with an original accession date of December 30, 2013; and the *Bacillus lijrens* strain has the accession number CGMCC No. 1.10239, with an original accession date of October 16, 2009. All three strains can be obtained through the preservation center and do not require biological preservation.

[0034] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 1:1.

[0035] The microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of 2:1.

[0036] The preparation method of the mature organic matter carrier is as follows: livestock and poultry manure and straw are mixed at a mass ratio of 3:1, fermentation inoculants are added, and composting is carried out under ventilated conditions for 30-45 days until the material is fully decomposed, odorless, with a total nutrient content ≥5% and an organic matter content ≥30%; the fermentation inoculant is a mixture of Bacillus subtilis, Bacillus licheniformis and EM bacteria at a live bacteria ratio of 1:1:2, and the inoculation amount is 0.3%.

[0037] The water-retaining agent is sodium polyacrylate; the pH buffer is a mixture of potassium dihydrogen phosphate and calcium carbonate in a weight ratio of 3:1.

[0038] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus purpureus, Halobacillus flavus, and Bacillus listiformis were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed cultures of *Monascus purpureus*, *Haemophilus spp.*, and *Bacillus lignosticus* were mixed at a volume ratio of 3:2:1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid-state fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid-state fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10 parts of inorganic nutrient components, 15 parts of functional compound microbial agent prepared in step (4), 0.5 parts of microbial activity promoter A, 1 part of microbial activity promoter B, 30 parts of organic matter carrier decomposed in step (1), 1 part of water-retaining agent, and 2 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated into granules with a particle size of 2-4 mm using an extrusion granulation process. The granules are then dried until the moisture content is ≤8%, resulting in a stable fertilizer with growth-promoting and stress-resistant functions. The product performance is tested according to the corresponding methods in the national quality standard for organic fertilizer NY525-2021. The product has an organic matter content of ≥60%, a moisture content of ≤10%, a pH of 6-9, and an effective viable bacteria count of ≥100 million / g.

[0039] In step (2), the activation medium for *Monascus xerophyticus* is malt extract medium with a natural pH and a culture temperature of 25-27℃; the activation medium for *Haloxybacterium flavonoids* is LB medium with a pH of 7.0-7.2 and a culture temperature of 28-30℃; and the activation medium for *Bacillus lijrens* is NA medium with a pH of 7.0-7.5 and a culture temperature of 28-30℃.

[0040] Antagonistic Experiment: The antagonistic effect among the strains was determined using the plate confrontation method. The three activated strains were streaked in pairs onto the same culture medium plate and incubated at 28℃ for 72-90 hours. No obvious inhibition bands were observed, indicating no antagonistic effect among the three strains. The culture effect was as follows: Figure 1 As shown.

[0041] Example 2 A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 15 parts inorganic nutrient components, 20 parts functional compound microbial agent, 1.5 parts microbial activity promoter A, 1.5 parts microbial activity promoter B, 30 parts decomposed organic matter carrier, 1 part water-retaining agent, and 2 parts pH buffer.

[0042] The inorganic nutrient components include nitrogen, phosphorus, and potassium, with a mass ratio of N:P2O5:K2O = 16:13:13.

[0043] The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Haemophilus flavonoids* strain has the accession number CGMCC No. 1.12756, with an original accession date of December 30, 2013; and the *Bacillus lijrens* strain has the accession number CGMCC No. 1.10239, with an original accession date of October 16, 2009. All three strains can be obtained through the preservation center and do not require biological preservation.

[0044] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 3:1.

[0045] The microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of 5:1.

[0046] The method for preparing the composted organic matter carrier is as follows: livestock and poultry manure and straw are mixed at a mass ratio of 3:1, fermentation inoculants are added, and composting is carried out under ventilated conditions for 30-45 days until the material is fully composted, odorless, with a total nutrient content ≥5% and an organic matter content ≥30%; the fermentation inoculant is a mixture of Bacillus subtilis, Bacillus licheniformis and EM bacteria at a live bacteria ratio of 1:1:2, and the inoculation amount is 0.3%-0.5%.

[0047] The water-retaining agent is sodium polyacrylate; the pH buffer is a mixture of potassium dihydrogen phosphate and calcium carbonate in a weight ratio of 3:1.

[0048] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus purpureus, Halobacillus flavus, and Bacillus listiformis were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed cultures of *Monascus purpureus*, *Haemophilus spp.*, and *Bacillus lignosticus* were mixed at a volume ratio of 3:2:1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid-state fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid-state fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 15 parts of inorganic nutrient components, 20 parts of functional compound microbial agent prepared in step (4), 1.5 parts of microbial activity promoter A, 1.5 parts of microbial activity promoter B, 30 parts of decomposed organic matter carrier in step (1), 1 part of water-retaining agent, and 2 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated into granules with a particle size of 2-4 mm using an extrusion granulation process. The granules are then dried until the moisture content is ≤8%, resulting in a stable fertilizer with growth-promoting and stress-resistant functions. The product performance is tested according to the corresponding methods in the national quality standard for organic fertilizer NY525-2021. The product has an organic matter content of ≥60%, a moisture content of ≤10%, a pH of 6-9, and an effective viable bacteria count of ≥100 million / g.

[0049] In step (2), the activation medium for *Monascus xerophyticus* is malt extract medium with a natural pH and a culture temperature of 25-27℃; the activation medium for *Haloxybacterium flavonoids* is LB medium with a pH of 7.0-7.2 and a culture temperature of 28-30℃; and the activation medium for *Bacillus lijrens* is NA medium with a pH of 7.0-7.5 and a culture temperature of 28-30℃.

[0050] Example 3 A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0051] The inorganic nutrient components include nitrogen, phosphorus, and potassium, with a mass ratio of N:P2O5:K2O=20:15:15.

[0052] The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Haemophilus flavonoids* strain has the accession number CGMCC No. 1.12756, with an original accession date of December 30, 2013; and the *Bacillus lijrens* strain has the accession number CGMCC No. 1.10239, with an original accession date of October 16, 2009. All three strains can be obtained through the preservation center and do not require biological preservation.

[0053] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 5:1.

[0054] The microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of 10:1.

[0055] The method for preparing the composted organic matter carrier is as follows: livestock and poultry manure and straw are mixed at a mass ratio of 3:1, fermentation inoculants are added, and composting is carried out under ventilated conditions for 30-45 days until the material is fully composted, odorless, with a total nutrient content ≥5% and an organic matter content ≥30%; the fermentation inoculant is a mixture of Bacillus subtilis, Bacillus licheniformis and EM bacteria at a live bacteria ratio of 1:1:2, and the inoculation amount is 0.3%-0.5%.

[0056] The water-retaining agent is sodium polyacrylate; the pH buffer is a mixture of potassium dihydrogen phosphate and calcium carbonate in a weight ratio of 3:1.

[0057] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus purpureus, Halobacillus flavus, and Bacillus listiformis were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed cultures of *Monascus purpureus*, *Haemophilus spp.*, and *Bacillus lignosticus* were mixed at a volume ratio of 3:2:1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid-state fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid-state fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated into granules with a particle size of 2-4 mm using an extrusion granulation process. The granules are then dried until the moisture content is ≤8%, resulting in a stable fertilizer with growth-promoting and stress-resistant functions. The product performance is tested according to the corresponding methods in the national quality standard for organic fertilizer NY525-2021. The product has an organic matter content of ≥60%, a moisture content of ≤10%, a pH of 6-9, and an effective viable bacteria count of ≥100 million / g.

[0058] In step (2), the activation medium for *Monascus xerophyticus* is malt extract medium with a natural pH and a culture temperature of 25-27℃; the activation medium for *Haloxybacterium flavonoids* is LB medium with a pH of 7.0-7.2 and a culture temperature of 28-30℃; and the activation medium for *Bacillus lijrens* is NA medium with a pH of 7.0-7.5 and a culture temperature of 28-30℃.

[0059] Comparative Example 1 Compared to Example 3, the composition of the microbial strains in the functional compound microbial agent was changed, that is, only *Monascus purpureus* and *Haemophilus flavonoids* were used: The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Haemophilus flavonoids* strain has the accession number CGMCC No. 1.12756, with an original accession date of December 30, 2013. Both strains can be obtained through the conservation center and do not require biological preservation.

[0060] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus xeroides and Haloxylon ammodendron were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed liquids of *Monascus purpureus* and *Haloxybacterium tumefaciens* were mixed at a volume ratio of 3:2. The mixed bacterial liquid was then inoculated into a solid fermentation substrate composed of wheat bran, rice bran, and decomposed organic carrier at an inoculation rate of 10%-15%. Solid fermentation was carried out for 5-10 days at 28-30℃ and 50%-70% humidity, with the substrate turned over every 24 hours until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated by extrusion granulation process to produce granules with a particle size of 2-4 mm. The granules are then dried until the moisture content is ≤8% to obtain a stable fertilizer with growth-promoting and stress-resistant functions.

[0061] Comparative Example 2 Compared to Example 3, the composition of the microbial strains in the functional compound microbial agent was changed, that is, only *Monascus purpureus* and *Bacillus listerius* were used: A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0062] The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the *Monascus purpureus* strain has the accession number CGMCC No. 3.18022, with an original accession date of June 1, 2016; the *Bacillus lijrens* strain has the accession number CGMCC No. 1.10239, with an original accession date of October 16, 2009. Both strains can be obtained through the preservation center and do not require biological preservation.

[0063] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus xerophyte and Bacillus lijrenaeus were inoculated into their respective activation media and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed liquids of *Monascus purpureus* and *Bacillus lignosticus* were mixed at a volume ratio of 3:1. The mixed bacterial liquid was then inoculated into a solid fermentation substrate composed of wheat bran, rice bran, and decomposed organic carrier at an inoculation rate of 10%-15%. Solid fermentation was carried out for 5-10 days at 28-30℃ and 50%-70% humidity, with the substrate turned over every 24 hours until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated by extrusion granulation process to produce granules with a particle size of 2-4 mm. The granules are then dried until the moisture content is ≤8% to obtain a stable fertilizer with growth-promoting and stress-resistant functions.

[0064] Comparative Example 3 Compared to Example 3, the composition of the microbial strains in the functional compound microbial agent was changed, that is, only *Halobacterium flavonoids* and *Bacillus listerius* were used: A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0065] The functional compound microbial agent contains *Hydroxybacterium fulvicii* (… Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the preservation number of the *Haloxysporum tobira* strain is CGMCC No. 1.12756, and the original preservation date is December 30, 2013; the preservation number of the *Bacillus lijrens* strain is CGMCC No. 1.10239, and the original preservation date is October 16, 2009. Both strains can be obtained through the preservation center and do not require biological preservation.

[0066] A method for preparing a stable fertilizer with growth-promoting and stress-resistance functions includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: *Haloxybacterium fulvicii* and *Bacillus listi* were inoculated into their respective activation media and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed cultures of *Haloxybacterium flavonoids* and *Bacillus ligeri* were mixed at a volume ratio of 2:1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated by extrusion granulation process to produce granules with a particle size of 2-4 mm. The granules are then dried until the moisture content is ≤8% to obtain a stable fertilizer with growth-promoting and stress-resistant functions.

[0067] Comparative Example 4 In this comparative example, except for the absence of microbial activity promoter A, the preparation steps are exactly the same as in Example 3, namely: A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0068] The microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of 10:1.

[0069] Comparative Example 5 In this comparative example, except for the absence of microbial activity promoter B, the preparation steps are exactly the same as in Example 3, namely: A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0070] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 5:1.

[0071] Comparative Example 6 This comparative example is identical to Example 3 except that L-fucose is not used in microbial activity promoter B. A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0072] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 5:1.

[0073] The microbial activity promoter B is vitamin B7.

[0074] Comparative Example 7 This comparative example is identical to Example 3 in all preparation conditions except that vitamin B7 is not used in microbial activity promoter B. A stable fertilizer with growth-promoting and stress-resistant functions comprises the following raw materials in parts by weight: 20 parts inorganic nutrient components, 25 parts functional compound microbial agent, 3 parts microbial activity promoter A, 2 parts microbial activity promoter B, 40 parts decomposed organic matter carrier, 3 parts water-retaining agent, and 4 parts pH buffer.

[0075] The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of 5:1.

[0076] The microbial activity promoter B is L-fucose.

[0077] Performance testing strain resistance Salt tolerance test: Equal concentrations of *Monascus purpureus*, *Haemophilus flavonoids*, and *Bacillus ligelli* were inoculated into LB liquid medium with different NaCl concentrations (1%, 7%, 12%) (three replicates were set up, and the mean value was taken). The medium was incubated at 25-30℃ and 220 r / min for 72 h, and the OD values ​​of the culture media under different treatments were measured. 600 To determine the NaCl tolerance of the strain.

[0078] Acid and alkali tolerance test: Equal concentrations of *Monascus purpureus*, *Haemophilus flavonoids*, and *Bacillus ligelli* were inoculated into LB liquid medium at different pH values ​​(4.0, 7.0, 10.0) (three parallel groups were set up, and the average result was taken). The medium was incubated at 25-30℃ and 220 r / min for 72 h, and the OD values ​​of the culture media under different treatments were measured. 600 To determine the acid and alkali tolerance of the strain Drought tolerance determination: Drought stress was simulated using PEG6000, with different concentration gradients of 20, 60, and 120 g / L (three parallel groups were set up, and the results were averaged). Inoculated with bacterial suspensions of *Monascus purpureus*, *Haemophilus flavonoids*, and *Bacillus ligeri* at the same concentrations into LB liquid medium containing different concentrations of PEG6000, and cultured at 25-30℃ and 220 r / min for 72 h, the OD values ​​of the culture media under different treatments were measured. 600 To determine the drought resistance of the strain.

[0079] Temperature tolerance test: Equal concentrations of *Monascus purpureus*, *Haemophilus flavonoids*, and *Bacillus ligeri* were inoculated into LB liquid medium (three parallel groups were set up, and the mean value was taken). The medium was incubated at 4, 28, and 45℃ for 72 h, and the OD values ​​of the culture media under different treatments were measured. 600 To determine the temperature tolerance of the strain.

[0080] Table 1 Tolerance of different strains

[0081] As shown in Table 1, the strains exhibited differentiated tolerance characteristics under different stress conditions. *Haloxybacterium fulvidracosum* showed the most outstanding performance under salt stress, maintaining an OD600 of 1.80 even at a 12% NaCl concentration, significantly higher than *Monascus purpureus* (0.63) and *Bacillus lignosticus* (0.51), demonstrating extremely strong salt tolerance. In an alkaline environment of pH 10.0, its OD600... 600 The value was 1.92, also higher than the other two strains, indicating that its alkali resistance was also quite excellent. The OD value of *Monascus purpureus* at 45℃ was... 600 The OD value was 1.82, slightly higher than that of *Haloxybacterium flavonoids* (1.71) and *Bacillus listerius* (1.60), indicating a slight advantage in temperature tolerance. While *Bacillus listerius* showed generally weaker tolerance to various stress conditions than *Haloxybacterium flavonoids*, it exhibited a higher OD value in an acidic environment at pH 4.0. 600 The value was 0.30, higher than that of *Monascus purpureus* (0.10) and *Haemophilus flavonoids* (0.05), indicating relatively good acid resistance potential. Overall, the three strains each have their own strengths in salt tolerance, alkali tolerance, temperature tolerance, and drought tolerance, which provides a basis for functional compound microbial agents to enhance overall stress resistance through synergistic effects among strains.

[0082] Growth-promoting ability test of strains: The functions of salt and alkali tolerance, drought tolerance, ACC deaminase, phosphorus solubilization, potassium solubilization, nitrogen fixation, and IAA production were verified by referring to existing technologies (Zhang Zhidong, Gu Meiying, Tang Qiyong, et al. Screening and hole planting verification of salt-tolerant growth-promoting bacteria in rhizosphere of *Salmonella salina* [J]. China Agricultural Science and Technology Guide, 2021, 23(3):186-192.) Table 2 Results of strain growth-promoting ability test

[0083] Note: ++: Growing well; +: Growing; -: Not growing Based on the data analysis in Table 2, the three strains exhibited significant complementary characteristics in terms of growth-promoting functions. *Monascus xerophyticus* showed "++" levels in both siderophore production and ACC deaminase activity, indicating a strong iron chelating ability and potential to reduce ethylene stress in plants. However, its phosphorus solubilization and nitrogen fixation abilities were not detected (marked as "-"), while its potassium solubilization ability was "+". *Haloxybacterium fulvidracosum* showed "++" levels in both ACC deaminase activity and IAA production, possessing both phosphorus solubilization and nitrogen fixation abilities ("+"), but lacking potassium solubilization ability ("-"), and its siderophore production capacity was relatively weak ("+"). *Bacillus lijrens* showed "+" or "++" activities in phosphorus solubilization, potassium solubilization, nitrogen fixation, and IAA production, demonstrating a relatively comprehensive nutrient conversion and supply capacity; however, its ACC deaminase activity was only "+", and its siderophore production capacity was also "+". All three strains can produce IAA (auxin), with *Monascus xerophyticus* and *Haloxera flavum* exhibiting stronger IAA production ("++"), which has a direct positive effect on promoting plant growth. Overall, the siderophore supply and ethylene regulation advantages of *Monascus xerophyticus*, the nitrogen and phosphorus supply and ACC deaminase activity of *Haloxera flavum*, and the phosphorus, potassium, and nitrogen comprehensive conversion capacity of *Bacillus listiformis* collectively constitute a diversified growth-promoting functional system of the compound microbial agent. Through the synergistic effect among strains, multidimensional promotion of plant growth can be achieved.

[0084] Planting experiment: Fertilizers were prepared according to the examples and comparative methods, and planting trials were conducted. The experiments were continued at Stanley Henan Company in Shangqiu, from 2022 to 2023. The previous crop was soybean, the soil was mixed soil (a combination of soil and fertilizer), with an organic matter content of 1.10%, available nitrogen content of 35.6 mg / kg, available phosphorus content of 25.95 mg / kg, and available potassium content of 110 mg / kg. Temperature, precipitation, and sunshine duration during the growing season are detailed below. Figure 2 .

[0085] Experimental Design: Under drought stress conditions, the normal irrigation volume at the jointing stage is 750 m³. 3 / hm 2 The drought stress treatment was a 50% reduction in irrigation, i.e., 375 m³. 3 / hm 2 All other management measures remained consistent. The tested crop was "Pinyu 8161". The experiment consisted of 11 treatment groups, with 3 replicates per treatment group, for a total of 33 plots arranged in a randomized block design, with each plot area of ​​20 m². The treatments included: T1: Blank control (no fertilizer applied), drought stress treatment; T2: Organic fertilizer from Example 1, drought stress treatment; application rate: 100 kg / hm²; T3: Organic fertilizer from Example 2, drought stress treatment; application rate: 100 kg / hm²; T4: Organic fertilizer from Example 3, drought stress treatment; application rate: 100 kg / hm²; T5: Comparative Example 1 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T6: Comparative Example 2 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T7: Comparative Example 3 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T8: Comparative Example 4 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T9: Comparative Example 5 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T10: Comparative Example 6 organic fertilizer, drought stress treatment; application rate: 100 kg / hm²; T11: Comparative Example 7 organic fertilizer, drought stress treatment. Application rate: 100 kg / hm²; At maturity, morphological parameters (ear length, thousand-grain weight, phenylalanine ammonia-lyase and peroxidase activities) of wheat plants in the experimental and control groups were measured.

[0086] Ear length, yield, and three yield factors: At maturity, 20 wheat samples with consistent plant height and growth stage were selected from each plot for seed testing, and ear length, number of grains per ear, and thousand-grain weight were calculated; the number of ears was investigated in a 1 m double-row section; all wheat in each plot was harvested and threshed, and the yield was calculated.

[0087] The activities of phenylalanine amino-lyase (PAL) and peroxidase (POD) were determined by Suzhou Keming Biotechnology Co., Ltd. using lignin content kits, plant chlorophyll kits, and PAL and POD enzyme activity assay kits, and were all measured by colorimetric methods.

[0088] Soil samples were collected from each experimental plot at a depth of 0–20 cm using a soil sampler and ring sampler. A five-point sampling method was used for each plot. After sampling, the samples were combined into one sample, and plant debris and other impurities were removed. Water-stable aggregate analysis was then performed. Soil index testing: Soil bulk density was determined using the ring sampler method. Soil water-stable aggregate analysis was performed using the wet sieving method, with sieve aperture diameters of 2, 1, 0.5, 0.25, and 0.053 mm (Instrument model: DIK-2012 AGGREGATE ANALYZER; Manufacturer: Daikisoil & Moisture).

[0089] Table 3 Results of wheat planting experiment

[0090] As can be clearly seen from the data in Table 3, the wheat in each experimental group showed significant differences in various indicators. The wheat treated with the fertilizer of this invention generally performed better than the blank control group and the comparative groups. Among them, Example 3 showed the most outstanding comprehensive effect. Its ear length reached 9.25 cm, significantly higher than the 7.12 cm of the blank group; the thousand-grain weight was 41.50 g, an increase of 18.17% compared with the 35.12 g of the blank group; the activities of phenylalanine ammonia-lyase and peroxidase were 78.6 U / g and 240.2 U / g, respectively, compared with the 40.2 U / g and 150.6 U / g of the blank group, representing increases of 95.52% and 59.50%, respectively; and the yield reached 7350.2 kg / hm², an increase of 22.1% compared with the 6020.3 kg / hm² of the blank group.

[0091] The indicators of Examples 2 and 1 were also superior to those of the control group, indicating that the fertilizer's growth-promoting and stress-resistance effects gradually improved as the synergistic effect of the functional compound microbial inoculant and microbial activity promoters was enhanced. In the comparative examples, Comparative Examples 6 and 7 performed relatively well, with ear lengths of 8.70 cm and 8.65 cm, thousand-grain weights of 39.54 g and 39.30 g, and yields of 7050.9 kg / hm² and 7020.4 kg / hm², respectively. This may be because they only lacked a single component (L-fucose or vitamin B7) from microbial activity promoter B, while other effective components still played a role. However, their indicators were still lower than those of Example 3, indicating that the synergistic effect of L-fucose and vitamin B7 in microbial activity promoter B is crucial for improving fertilizer performance.

[0092] Comparative Examples 1 to 5 differed from the Examples in terms of raw material composition or preparation conditions, and all their indicators were lower than those of the Example group, further verifying the necessity of the synergistic combination of the raw material components in this invention. Overall, the stable fertilizer with growth-promoting and stress-resistance functions prepared by this invention, through the synergistic effect of functional compound microbial agents and the synergistic effect of microbial activity promoters, can effectively promote wheat growth, enhance its stress resistance, and thus significantly increase yield.

[0093] Table 4 Comparison of soil water-stable aggregates in each treatment group (0 ~ 20 cm)

[0094] As shown in Table 4, the mean weight diameter (MWD) and geometric weight diameter (GWD) of soil water-stable aggregates in each treatment group exhibited a similar trend to that of wheat growth indicators. The soil MWD and GWD values ​​of the treatment groups treated with the fertilizer of this invention were significantly higher than those of the blank control group. Specifically, Example 3 achieved a MWD of 1.25 mm and a GWD of 0.75 mm, representing increases of 140.38% and 167.86% respectively compared to the blank group's MWD of 0.52 mm and GWD of 0.28 mm, indicating the most significant improvement in soil structure. Example 2 had a MWD of 1.12 mm and a GWD of 0.68 mm, and Example 1 had a MWD of 0.96 mm and a GWD of 0.59 mm, all superior to the blank group, demonstrating that the enhanced synergistic effect of the functional compound microbial agents and microbial activity promoters in the fertilizer effectively improved the stability and structure of soil water-stable aggregates. Although the MWD and GWD values ​​of each comparative example group were generally higher than those of the control group, they were all lower than those of Example 3. Among them, the MWD of Comparative Example 6 was 1.00 mm and the GWD was 0.62 mm, and the MWD of Comparative Example 7 was 0.98 mm and the GWD was 0.60 mm, which showed relatively better performance, but were still not as good as those of the example groups. This further confirms that the fertilizer prepared by the present invention can create a more favorable soil environment for crop growth by improving soil structure and increasing the number and stability of water-stable aggregates.

[0095] In summary, the fertilizer of this invention exhibits significant advantages in promoting wheat growth, enhancing stress resistance, and improving soil structure, with Example 3 showing the most outstanding effect. Through the synergistic effect of functional microbial agents and activity promoters, it not only increases the content and stability of soil water-stable aggregates but also effectively enhances the soil's water and fertilizer retention capacity, providing a favorable environment for wheat root development and nutrient absorption. Field trial results consistently demonstrate that applying this fertilizer can significantly increase wheat yield and improve quality, showing broad prospects for widespread application.

[0096] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A stable fertilizer with growth-promoting and stress-resistance functions, characterized in that, The raw materials include the following parts by weight: 10-20 parts inorganic nutrients, 15-25 parts functional compound microbial agent, 0.5-3 parts microbial activity promoter A, 1-2 parts microbial activity promoter B, 30-40 parts decomposed organic matter carrier, 1-3 parts water-retaining agent, and 2-4 parts pH buffer.

2. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The inorganic nutrient components include nitrogen, phosphorus, and potassium, with a mass ratio of N:P2O5:K2O = 15-20:10-15:10-15.

3. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The functional compound microbial agent contains *Monascus purpureus* (…). Monascus eremophilus ), yellow salt-tolerant bacteria ( Halodurantibacterium flavum ), Bacillus lijrens ( Paenibacillus jilunlii The total viable count is not less than 2.0 × 10⁻⁶. 9 CFU / g; the preservation number of the xerophytic red Monascus is CGMCC No.3.18022; the preservation number of the yellow halophilic bacillus is CGMCC No.1.12756; the preservation number of the Bacillus lijrens is CGMCC No.1.10239.

4. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The microbial activity promoter A is a mixture of trehalose and chitosan oligosaccharide in a weight ratio of (1:1) to (5:1).

5. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The microbial activity promoter B is a mixture of L-fucose and vitamin B7 in a weight ratio of (2:1) to (10:1).

6. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The preparation method of the mature organic matter carrier is as follows: livestock and poultry manure and straw are mixed at a mass ratio of 3:1, fermentation inoculants are added, and composting is carried out under ventilated conditions for 30-45 days until the material is fully decomposed, odorless, with a total nutrient content ≥5% and an organic matter content ≥30%; the fermentation inoculants are composed of Bacillus subtilis, Bacillus licheniformis and EM bacteria mixed at a live bacteria ratio of 1:1:2, and the inoculation amount is 0.3%-0.5%.

7. The stable fertilizer with growth-promoting and stress-resistance functions according to claim 1, characterized in that, The water-retaining agent is sodium polyacrylate; the pH buffer is a mixture of potassium dihydrogen phosphate and calcium carbonate in a weight ratio of 3:

1.

8. A method for preparing a stable fertilizer with growth-promoting and stress-resistant functions as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Preparation of decomposed organic matter carrier; (2) Activation of bacterial strains: Monascus purpureus, Halobacillus flavus, and Bacillus listiformis were inoculated into the corresponding activation medium and cultured at 25-30℃ with shaking for 3-5 days until the bacterial culture reached OD500. 600 When the value reaches 2.0, an activated bacterial solution is obtained; (3) Seed culture expansion: The activated bacterial solution was inoculated into the seed tank culture medium at an inoculation rate of 5%, and cultured at 25-30℃ and a stirring speed of 200 r / min for 18-24 h until the viable count reached 1.0 × 10⁻⁶. 10 CFU / mL was used to obtain seed solutions for each strain; (4) Mixed fermentation: The seed cultures of *Monascus purpureus*, *Haemophilus spp.*, and *Bacillus lignosticus* were mixed at a volume ratio of 3:2:

1. The mixed culture was then inoculated at 10%-15% of the total culture into a solid-state fermentation substrate composed of wheat bran, rice bran, and well-rotted organic carrier. Solid-state fermentation was carried out at 28-30℃ and 50%-70% humidity for 5-10 days, with the substrate turned over every 24 hours, until the total viable count was not less than 2.0 × 10⁻⁶. 9 CFU / g yields a fermentation product rich in microbial cells and their metabolites, which is the functional compound microbial agent; the solid fermentation substrate is a mixture of wheat bran, rice bran and the decomposed organic carrier prepared in step (1) in a mass ratio of 2:1:

1. (5) Raw material mixing: Weigh out 10-20 parts of inorganic nutrient components, 15-25 parts of functional compound microbial agent prepared in step (4), 0.5-3 parts of microbial activity promoter A, 1-2 parts of microbial activity promoter B, 30-40 parts of organic matter carrier decomposed in step (1), 1-3 parts of water-retaining agent, and 2-4 parts of pH buffer. Put the above raw materials into a double helix mixer and mix for 15-20 minutes at a speed of 150-200 r / min to obtain a mixture. (6) Granulation and drying: The mixture obtained in step (5) is fed into a granulator and granulated by extrusion granulation process to produce granules with a particle size of 2-4 mm. The granules are then dried until the moisture content is ≤8% to obtain a stable fertilizer with growth-promoting and stress-resistant functions.

9. The method for preparing a stable fertilizer with growth-promoting and stress-resistant functions according to claim 8, characterized in that, In step (2), the activation medium for *Monascus xerophyticus* is malt extract medium with a natural pH and a culture temperature of 25-27℃; the activation medium for *Haloxybacterium flavonoids* is LB medium with a pH of 7.0-7.2 and a culture temperature of 28-30℃; and the activation medium for *Bacillus lijrens* is NA medium with a pH of 7.0-7.5 and a culture temperature of 28-30℃.

10. The application of a stable fertilizer with growth-promoting and stress-resistance functions as described in any one of claims 1-6 in improving soil structure, promoting wheat growth, and enhancing wheat's drought and salt tolerance.

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