Organic fertilizer formula with soil improvement function and preparation method thereof

Abstract

The invention discloses an organic fertilizer with a soil improvement function and a preparation method of the organic fertilizer, and the integrated target of heavy metal passivation, saline-alkali regulation and fertilizer efficiency slow release is achieved through kitchen waste, straw and biochar multi-source organic matter compounding, staged functional fungicide adding and intelligent temperature control processes. After the soil conditioner is applied, the soil pH adjusting amplitude reaches 1.0-1.5 units, the heavy metal migration rate is reduced by 65% or above, the crop yield is increased by 15%-25%, and the soil conditioner is suitable for green remediation of degraded soil.

Description

Technical Field

[0001] The present invention relates to the technical field of organic fertilizers, in particular to an organic fertilizer formula with soil improvement function and a preparation method thereof. Background Art

[0002] Soil degradation has become a global agricultural problem. Although traditional organic fertilizers can replenish organic matter, they face the following technical bottlenecks in practical application:

[0003] Functional drawbacks: Conventional organic fertilizers, primarily based on livestock and poultry manure or straw compost, lack the ability to chelate heavy metal ions (such as Cd and Pb), preventing the migration of pollutants to crops. Studies have shown that conventional compost fixes less than 30% of cadmium, while the present invention achieves over 65%.

[0004] Salt-alkali land improvement relies on chemical amendments such as gypsum or sulfur, which can easily cause soil compaction and fail to simultaneously increase organic matter content. For example, in saline-alkali land in North China, applying conventional organic fertilizers only reduces soil pH by 0.3-0.5 units, while the present invention can reduce it by 1.0-1.3 units.

[0005] Microbial activity constraints: The survival rate of a single bacterial species (such as Bacillus subtilis) during the high-temperature fermentation stage (>50°C) is less than 20%, resulting in poor subsequent colonization. However, the present invention increases the bacterial colony survival rate to 85% by inoculating thermotolerant and mesophilic bacteria in stages.

[0006] In the traditional process, the bacterial agent and the raw materials are not mixed evenly, and the effective colonization area of the functional bacteria in the soil is less than 40%. However, the present invention increases the colonization area to 75% through rotary spraying and carrier adsorption technology.

[0007] Conflict between resource utilization and environmental protection: my country produces 120 million tons of food waste and 1 billion tons of straw annually. However, existing methods of directly composting food waste easily produce foul-smelling gases (such as NH3 and H2S) and are not combined with adsorbent materials such as biochar, resulting in a carbon loss rate of up to 45%. The present invention reduces this carbon loss rate to below 15% through biochar coating pretreatment.

[0008] Insufficient slow-release performance: The organic carbon release period of conventional organic fertilizers is only 2-3 months, requiring frequent topdressing. However, the present invention uses starch-based coating technology to extend the slow-release period to 6-8 months, reducing the frequency of fertilization by 50%. Summary of the Invention

[0009] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0010] In view of the above problems in the prior art, the inventors proposed the present invention.

[0011] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide an organic fertilizer formulation with soil improvement function.

[0012] To solve the above technical problems, the present invention provides the following technical solution: an organic fertilizer with soil improvement function, comprising the following steps:

[0013] The organic fertilizer formula comprises the following components, calculated by weight percentage of raw materials: 30%-40% of kitchen waste, 20%-25% of crop straw, 15%-20% of livestock and poultry manure, 5%-10% of biochar, 1%-3% of functional bacterial agent, 3%-5% of humic acid chelating agent, and 2%-5% of seaweed extract.

[0014] As a preferred embodiment of the organic fertilizer with soil improvement function of the present invention, the functional bacterial agent is compounded by high-temperature decomposition bacteria, heavy metal passivation bacteria, and salt-alkali tolerance bacteria in a ratio of 1:1:2.

[0015] As a preferred embodiment of the organic fertilizer with soil improvement function of the present invention, the humic acid chelating agent is a complex of humic acid, iron and zinc, and the complex molar ratio is 1:1.5.

[0016] The present invention also provides a method for preparing an organic fertilizer having a soil-improving function, which comprises the following steps:

[0017] Raw material pretreatment

[0018] Staged temperature-controlled fermentation

[0019] Add functional bacterial agents

[0020] Curing and granulation.

[0021] As a preferred embodiment of the method for preparing organic fertilizer with soil improvement function of the present invention, the staged temperature-controlled fermentation includes: a high temperature stage (50-65°C, 5-7 days), a medium temperature stage (35-45°C, 10-12 days), and a normal temperature maturation stage (25-30°C, 15-20 days).

[0022] As a preferred embodiment of the method for preparing organic fertilizer with soil improvement function of the present invention, high temperature-resistant decomposition bacteria are added in the high temperature stage, heavy metal passivation bacteria and humic acid are added in the medium temperature stage, and salt-alkali tolerant bacteria are added in the normal temperature stage.

[0023] As a preferred embodiment of the method for preparing organic fertilizer with soil improvement function of the present invention, a vertical multi-layer fermentation device is used to evenly spray the bacterial agent through a rotating nozzle.

[0024] The present invention also provides an organic fertilizer application method for improving salinized soil, comprising the following steps: a) applying organic fertilizer at a dosage of 300-500 kg per mu evenly to the surface layer of target soil, wherein the soil has a pH value of 8.5-9.5 and an electrical conductivity of 3.5-6.0 dS / m;

[0025] b) After fertilization, mix the organic fertilizer with the top 20-30 cm of soil by tilling. The frequency of tilling is once every 7 days, and the tillage is repeated 2-3 times;

[0026] c) Cooperate with the drip irrigation system to regulate water content and maintain the soil moisture content at 60%-70% for 6-8 months;

[0027] d) The biochar content in the organic fertilizer is 5%-10%, the seaweed extract content is 4%-5%, and the salt-alkali tolerant bacteria (Halomonas sp) are added during the normal temperature maturation stage, and the number of viable bacteria in the bacterial agent is ≥1×10 8 CFU / g.

[0028] The present invention also provides an organic fertilizer application method for remediating heavy metal contaminated soil, comprising the following steps: a) mixing the organic fertilizer with potassium dihydrogen phosphate at a mass ratio of 10:1, and applying the mixture to the contaminated soil at a dosage of 400-600 kg per mu, wherein the effective cadmium content in the soil is ≥1.0 mg / kg;

[0029] b) After fertilization, cover with degradable mulch (thickness 0.02-0.05mm), maintain soil temperature at 25-35°C and humidity at 50%-60% for 3-4 months;

[0030] c) the humic acid chelating agent in the organic fertilizer is a complex of humic acid and zinc, the complex molar ratio is 1:1.5, and the biochar content is 8%-10%;

[0031] d) The concentration of Pseudomonas fluorescens added during the medium-temperature fermentation stage was 2×10 8 -5×10 8 CFU / g, and after colonization in the soil, it secretes hydrogen sulfide (H2S) at a rate of 0.5-1.2 μmol / g·d.

[0032] The present invention also provides an organic fertilizer application system for improving crop stress resistance:

[0033] a) compounding organic fertilizer and Trichoderma harzianum spore powder in a mass ratio of 100:1 to form a stress-resistant compound fertilizer;

[0034] b) 7-10 days before sowing the crop, apply compound fertilizer to the soil at a rate of 200-300kg per mu and mix it with the root growth layer (depth of 10-15cm);

[0035] c) During the crop growth period, additional spraying of seaweed extract diluted solution (concentration 0.5%-1.0%) is performed every 30 days at a spraying rate of 50-80 L / mu;

[0036] d) The stress resistance includes drought resistance, disease resistance and salt stress resistance.

[0037] The invention has the following beneficial effects: through the dual mechanisms of ion exchange and biosorption, the effective cadmium in the soil is converted into a residual state, with a passivation efficiency of 65%-75%, and the cadmium content in crop grains is reduced to below 0.1 mg / kg; the biochar and seaweed extract form an acid-base buffer system, which reduces the pH value of the soil while increasing the sodium ion adsorption capacity by 40% and the organic matter content by 1.2%-1.8%; the staged temperature control process enables the thermotolerant bacteria to quickly decompose lignin during the high temperature period, creating a living environment for the mesophilic bacteria, and the final bacterial population density reaches 5×10 8 The synergistic fermentation of food waste and straw stabilizes the carbon-nitrogen ratio (C / N) at 25-30, shortens the fermentation cycle to 25 days, and reduces malodorous gas emissions by 80%. The starch-based coating material gradually degrades in the soil, maintaining a nitrogen release rate of 60%-70% within six months, reducing nutrient loss and increasing corn yields by 15%-20%. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0041] Example 1

[0042] This embodiment provides an implementation method of using an organic fertilizer with soil improvement function in improving salinized soil.

[0043] Target soil properties: pH 8.5-9.2, conductivity 4.0-5.5 dS / m, organic matter content <1.0%.

[0044] Formula: Kitchen waste (35%), straw (22%), livestock and poultry manure (18%), biochar (8%), functional bacteria (2.5%), seaweed extract (4.5%), and humic acid chelated iron (3%). Fermentation is carried out in three stages: high temperature (65°C / 6 days), medium temperature (40°C / 12 days), and room temperature (28°C / 20 days). A starch coating agent is added during the maturation stage.

[0045] Dosage and method:

[0046] Apply 400kg of organic fertilizer per mu and spread it evenly on the soil surface;

[0047] The tillage depth is 25 cm, and the frequency is once every 7 days, for a total of 3 times;

[0048] Drip irrigation maintained soil moisture at 65% for 6 months.

[0049] Application effect:

[0050]

[0051]

[0052] Mechanism of action analysis:

[0053] Physical-chemical synergistic desalination of biochar

[0054] Sodium ion adsorption: The surface of biochar is rich in oxygen-containing functional groups (-COOH, -OH), which adsorb Na through ion exchange. + (adsorption capacity 85mg / g), reduces the conductivity of soil solution.

[0055] Pore retention: Mesoporous structure (pore size 2-50nm) retains Na + -Cl - ion pairs, inhibiting their migration to the upper layer.

[0056] Biochemical buffering of seaweed extracts

[0057] Proton release: Alginate oligosaccharides (AOS) activate H in plant roots + -ATPase, secretes H + Replacement of colloid-adsorbed Na + (H + / Na+ The exchange ratio is increased by 2.5 times).

[0058] Osmotic regulation: Mannitol and betaine reduce cell osmotic pressure and enhance crop salt tolerance (proline accumulation increases 3 times).

[0059] Biomineralization enhancement of functional bacteria

[0060] Extracellular polysaccharide encapsulation: EPS (containing glucuronic acid) secreted by Halomonas sp. and Na + An insoluble complex is formed (Na-EPS, solubility < 0.01 g / L).

[0061] Carbon source supply: Maltose produced by the degradation of starch coating agent provides a continuous carbon source for the bacterial community (colonization density increases by 40%).

[0062] It can be seen that the adsorption capacity of biochar and the proton supply of seaweed extract form a "physical-chemical" synergistic salt reduction, and the biomineralization of functional bacteria prolongs the sustainability of the improvement effect. The combination of the three increases the desalination efficiency by 2.3 times.

[0063] Example 2

[0064] Remediation of heavy metal contaminated soil

[0065] Target soil properties: total cadmium content 1.5-2.0 mg / kg (3-4 times higher than the national standard), pH 5.5-6.5.

[0066] Recipe Optimization:

[0067] Increase the humic acid chelating agent to 5%, the biochar to 10%, and add an additional 2% potassium dihydrogen phosphate (to promote the conversion of cadmium into cadmium phosphate precipitation).

[0068] Dosage and operation:

[0069] Mix organic fertilizer and potassium dihydrogen phosphate at a ratio of 10:1 and apply 500 kg per mu;

[0070] Cover with 0.03mm biodegradable mulch and maintain the soil temperature at 30℃ and humidity at 55% for 4 months.

[0071] Key processes:

[0072] Humic acid and Pseudomonas fluorescens (2×10 8 CFU / g), and the particles were coated with sodium alginate-starch composite film at room temperature.

[0073] Repair effect:

[0074] The effective cadmium content dropped from 1.25 mg / kg to 0.42 mg / kg, with a passivation rate of 66.4%;

[0075] The cadmium content of rice grains is 0.11 mg / kg (the national standard limit is 0.2 mg / kg);

[0076] Soil catalase activity increased by 80% (indicating the recovery of microbial activity).

[0077] Mechanism of action analysis:

[0078] Humic acid-heavy metal complex

[0079] Chelation mechanism: carboxyl groups of humic acid and Cd 2+ Formation of [HCd(OOCR)2] + The complex (logK=5.2) is stable in the pH range of 5-9.

[0080] Electronic shielding: π-π conjugation of phenolic hydroxyl groups reduces Cd 2+ activity, reducing plant absorption (Cd accumulation on the root surface decreased by 60%).

[0081] Biochar-phosphate precipitation

[0082] Loading phosphate: biochar adsorbs PO4 3- , and Cd 2+ Cd3(PO4)2 precipitate is generated (solubility product Ksp = 2.5×10 -33 ).

[0083] Nanoconfinement effect: The mesoporous structure limits the precipitate grain size (<100 nm) and inhibits redissolution.

[0084] Functional bacteria bioreduction

[0085] Sulfide production: Pseudomonas fluorescens expresses the cdsA gene, catalyzing the synthesis of H2S and producing CdS precipitates (Ksp = 1×10 -28 ).

[0086] Siderophore competition: secreted pyoverdine snatches Cd 2+ , forming inert nanoparticles (particle size 2-5nm).

[0087] It can be seen that chemical chelation (humic acid), biological transformation (functional bacteria) and precipitation reaction (phosphate) form a three-level passivation barrier, targeting different forms of cadmium (water-soluble, exchangeable, and carbonate-bound), and the comprehensive passivation efficiency is 35% higher than that of a single method.

[0088] Example 3

[0089] Soil remediation for continuous cropping obstacles

[0090] Target soil properties: fungal disease incidence >30%, organic matter <1.5%, microbial diversity index (Shannon) <2.5.

[0091] Furthermore, 1% of Trichoderma harzianum spore powder was added, and the proportion of actinomycetes (Streptomyces spp.) in the functional bacterial agent was increased to 30%.

[0092] Process adjustment:

[0093] The normal temperature aging stage is extended to 25 days to ensure that the germination rate of Trichoderma spores is greater than 90%.

[0094] Operation steps: Mix organic fertilizer and Trichoderma spore powder in a ratio of 100:1, apply 250 kg per mu to the soil 10 days before sowing; plow to a depth of 15 cm and mix with the root layer; spray 0.8% seaweed extract dilution (60 L / mu) every 30 days during the growing period.

[0095] Repair effect:

[0096] The abundance of soil-borne pathogens (Fusarium and Phytophthora) decreased by 85%;

[0097] The soil microbial Shannon index increased from 2.1 to 3.9;

[0098] Tomato yield increased by 22% and the incidence of bacterial wilt was less than 5%.

[0099] Mechanism of action analysis:

[0100] Parasitism and antagonism of Trichoderma

[0101] Heavy parasitism: Trichoderma secretes chitinase (>15U / g) to degrade the cell walls of pathogens (such as Fusarium), causing them to lyse.

[0102] Antibiotic inhibition: Gliotoxin production inhibits spore germination of pathogens (IC 50 =5 μM).

[0103] Chemical defenses of actinomycetes

[0104] Jinggangmycin secretion: blocks the sugar metabolism pathway of pathogens (inhibits hexokinase activity by 80%).

[0105] Quorum sensing interference: degrades pathogen AHLs signaling molecules and inhibits virulence gene expression.

[0106] Microecological construction of biochar

[0107] Pore protection: Biochar micropores (pore size <2nm) provide a microhabitat for beneficial bacteria to avoid ultraviolet and dry stress.

[0108] Slow-release carbon source: Adsorbed organic acids (such as citric acid) are gradually released to maintain bacterial metabolic activity (survival rate increased by 50%). This demonstrates that the secretion of antibacterial substances by the functional bacteria (actinomycetes) and the parasitic action of Trichoderma form a dual "inhibition-killing" pathway, while biochar ensures bacterial sustainability by establishing microecological niches. The three synergistically enhance pathogen control by 60%.

[0109] Furthermore, using multi-source organic waste as the basic raw material, combined with functional bacteria and functional additives, a trinity complex system of "nutrient supply-soil remediation-microbial regulation" is formed. The specific formula includes:

[0110] Organic matter module: kitchen waste (30%-40%), crop straw (20%-25%), livestock and poultry manure (15%-20%), optimizes microbial metabolic efficiency through dynamic balance of carbon-nitrogen ratio (C / N=25-30);

[0111] Functional carrier module: biochar (5%-10%), with a high specific surface area (>300m 2 / g) and multi-level pore structure (micropores <2nm, mesopores 2-50nm) provide adsorption sites and bacterial shelters;

[0112] Repair module:

[0113] Functional bacterial agent (1%-3%): thermostable decomposition bacteria (Bacillus subtilis), heavy metal passivation bacteria (Pseudomonas fluorescens), and salt-alkali tolerance bacteria (Halomonas sp) are mixed in a ratio of 1:1:2;

[0114] Functional additives: humic acid chelated iron / zinc (3%-5%), seaweed extract (2%-5%), starch-based sustained-release coating agent (1%-2%).

[0115] At the same time, a process combining staged temperature-controlled fermentation with intelligent equipment integration is adopted, specifically including:

[0116] Pretreatment stage: raw material crushing (particle size ≤ 2cm), moisture adjustment (55%-60%), bacterial agent activation (1%-2% brown sugar solution);

[0117] High-temperature decomposition stage (50-65°C, 5-7 days): The high-temperature resistant bacteria quickly degrade lignin and cellulose, releasing a fast-acting carbon source;

[0118] Medium-temperature remediation stage (35-45°C, 10-12 days): Add humic acid and heavy metal passivating bacteria to simultaneously fix heavy metal ions;

[0119] Normal temperature aging stage (25-30℃, 15-20 days): Introduce salt-alkali tolerant bacteria and slow-release coating materials to complete bacterial colonization and particle formation.

[0120] The combined effect of the three-level heavy metal passivation barrier enables the cadmium passivation efficiency to reach 65%-75%, which is 35%-40% higher than that of a single method.

[0121] Primary chemical complexation: carboxyl group (-COOH) of humic acid and Cd 2+ Forms a stable complex (stability constant logK = 5.2), reducing the activity of water-soluble heavy metals;

[0122] Secondary physical adsorption: biochar-loaded phosphate (PO4 3- ) and Cd 2+ The insoluble Cd3(PO4)2 precipitate is generated (solubility product Ksp = 2.5×10 -33 );

[0123] Three-stage biotransformation: Pseudomonas fluorescens secretes hydrogen sulfide (H2S) to convert Cd 2+ Converted to CdS (Ksp = 1 × 10 -28 ).

[0124] Through laboratory tests and field trials, the core indicators of this invention are significantly better than traditional organic fertilizers and similar patented technologies:

[0125] index Traditional organic fertilizer Similar patented technologies The present invention Heavy metal passivation rate (Cd) 20％-30％ 40％-50％ 65％-75％ pH adjustment range of saline-alkali land 0.3-0.5 units 0.8-1.0 units 1.0-1.5 units Functional bacteria colonization rate (30 days) 30％-40％ 50％-60％ 75％-85％ Organic carbon slow release cycle 2-3 months 4-5 months 6-8 months Malodorous gas emission reduction rate - 50％-60％ 80％-85％

[0126] Furthermore, from the perspective of economic benefits, using food waste and straw as the main raw materials can reduce the production cost per ton by 300-400 yuan; the average crop yield increases by 15%-25%, and the average income per mu increases by 200-300 yuan.

[0127] From the perspective of ecological benefits, repairing degraded soil can restore farming capacity in 5-8 years; every 10,000 tons of fertilizer can reduce CO2 emissions by 12 tons.

[0128] This invention, through its innovative design of multi-source organic matter compatibility, phased microbial activation, and cross-scale synergistic mechanisms, overcomes the technical challenges of traditional organic fertilizers, such as their single function, long remediation cycle, and low microbial survival rate. It achieves breakthroughs in key indicators such as heavy metal passivation efficiency (65%-75%), salinity regulation (pH reduction of 1.0-1.5 units), and microbial colonization rate (75%-85%). Combined with intelligent equipment and a modular formulation system, this product is widely adaptable to different degraded soil types, offering significant environmental and economic benefits and promising market prospects.

[0129] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. Organic fertilizer with soil improvement function, characterized by: The organic fertilizer formula comprises the following components, calculated by weight percentage of raw materials: 30%-40% of kitchen waste, 20%-25% of crop straw, 15%-20% of livestock and poultry manure, 5%-10% of biochar, 1%-3% of functional bacterial agent, 3%-5% of humic acid chelating agent, and 2%-5% of seaweed extract.

2. the organic fertilizer with soil improving function as claimed in claim 1, is characterized in that: The functional bacterial agent is compounded by high-temperature resistant decomposition bacteria, heavy metal passivation bacteria and salt-alkali tolerant bacteria in a ratio of 1:1:

2.

3. The organic fertilizer with soil improving function as claimed in claim 1, wherein: The humic acid chelating agent is a complex of humic acid, iron and zinc, and the complexing molar ratio is 1:1.

5.

4. A method for preparing an organic fertilizer with soil-improving function as claimed in any one of claims 1 to 3, comprising the following steps: Raw material pretreatment; Fermentation with controlled temperature in stages; Add functional bacterial agents; Curing and granulation.

5. The method for preparing organic fertilizer with soil improvement function as claimed in claim 4, wherein: The staged temperature-controlled fermentation includes: a high-temperature stage (50-65° C., 5-7 days), a medium-temperature stage (35-45° C., 10-12 days), and a normal-temperature maturation stage (25-30° C., 15-20 days).

6. The method for preparing an organic fertilizer having a soil improving function as claimed in claim 4, wherein: High-temperature-resistant decomposition bacteria are added in the high-temperature stage, heavy metal passivation bacteria and humic acid are added in the medium-temperature stage, and salt-alkali-tolerant bacteria are added in the normal-temperature stage.

7. The method for preparing an organic fertilizer having a soil improving function as claimed in claim 4, wherein: A vertical multi-layer fermentation device is used to evenly spray the bacterial agent through a rotating nozzle.

8. A method for applying organic fertilizer for improving salinized soil, characterized in that: The following steps are involved: a) applying the organic fertilizer according to claim 1 evenly to the surface of the target soil at an amount of 300-500 kg per mu, wherein the pH value of the soil is 8.5-9.5 and the electrical conductivity is 3.5-6.0 dS / m; b) After fertilization, mix the organic fertilizer with the top 20-30 cm of soil by tilling. The frequency of tilling is once every 7 days, and the tillage is repeated 2-3 times; c) Cooperate with the drip irrigation system to regulate water content and maintain the soil moisture content at 60%-70% for 6-8 months; d) The biochar content in the organic fertilizer is 5%-10%, the seaweed extract content is 4%-5%, and the salt-alkali tolerant bacteria (Halomonas sp) are added during the normal temperature maturation stage, and the number of viable bacteria in the bacterial agent is ≥1×10 8 CFU / g.

9. A method for applying organic fertilizer for remediation of heavy metal contaminated soil, characterized by: The following operations are included: a) mixing the organic fertilizer according to claim 1 with potassium dihydrogen phosphate in a mass ratio of 10:1, and applying the mixture to contaminated soil at a dosage of 400-600 kg per mu, wherein the available cadmium content in the soil is ≥1.0 mg / kg; b) After fertilization, cover with degradable mulch (thickness 0.02-0.05mm), maintain soil temperature at 25-35°C and humidity at 50%-60% for 3-4 months; c) the humic acid chelating agent in the organic fertilizer is a complex of humic acid and zinc, the complex molar ratio is 1:1.5, and the biochar content is 8%-10%; d) The concentration of Pseudomonas fluorescens added during the medium-temperature fermentation stage was 2×10 8 -5×10 8 CFU / g, and after colonization in the soil, it secretes hydrogen sulfide (H2S) at a rate of 0.5-1.2 μmol / g·d.

10. An organic fertilizer application system for improving crop stress resistance, characterized by: a) compounding the organic fertilizer according to claim 1 with Trichoderma spore powder in a mass ratio of 100:1 to form an adversity-resistant compound fertilizer; b) 7-10 days before sowing the crop, apply compound fertilizer to the soil at a rate of 200-300kg per mu and mix it with the root growth layer (depth of 10-15cm); c) During the crop growth period, additional spraying of seaweed extract diluted solution (concentration 0.5%-1.0%) is performed every 30 days at a spraying rate of 50-80 L / mu; d) The stress resistance includes drought resistance, disease resistance and salt stress resistance.

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