Multifunctional organic planting fertilizer and preparation method thereof

Abstract

The invention relates to the technical field of planting fertilizers, in particular to a multifunctional organic planting fertilizer and a preparation method thereof.The multifunctional organic planting fertilizer comprises an organic base material, a heavy metal passivation system, a slow release system, a microbial system and a function strengthening system, and is characterized in that the organic base material comprises, by weight, 20-30 parts of decomposed sheep manure; 15 to 20 parts of soybean meal; 10 to 15 parts of corn straw powder; the heavy metal passivation system comprises the following raw materials in parts by weight: 8-12 parts of attapulgite clay; 5 to 8 parts of humic acid; and 3-5 parts of bone black. The organic base material and the mineral material synergistically passivate heavy metals, the soil pollution risk is reduced, a slow release system is combined with microbial metabolism, long-term stable supply of nutrients is guaranteed, function strengthening components naturally expel insects, dependence on chemical pesticides is reduced, the decomposition degree and flora activity are accurately controlled in the whole-process technology, and it is ensured that the fertilizer is safe and efficient; compared with a traditional fertilizer, the fertilizer and the preparation process thereof have the functions of ecological restoration, nutrient long-acting and biological prevention and control.

Description

Technical Field

[0001] The present invention relates to the technical field of planting fertilizers, in particular to a multifunctional organic planting fertilizer and a preparation method thereof. Background Art

[0002] Fertilizers are substances that provide essential nutrients for crop growth, improve soil structure, and regulate ecological functions. Their core function is to promote healthy crop development and increase yields by supplementing nutrients such as nitrogen, phosphorus, and potassium, as well as organic matter. Traditional fertilizers are primarily chemically synthesized, supplemented with some organic ingredients. However, long-term reliance on these fertilizers can easily lead to soil degradation and environmental pollution.

[0003] However, in general, traditional fertilizers mostly use chemical synthetic ingredients such as urea and superphosphate, combined with inadequately treated livestock and poultry manure or straw compost. Such fertilizers have significant defects: the rapid release of chemical nutrients can easily lead to soil compaction and eutrophication of water bodies; uncomposted organic fertilizers carry pathogens and weed seeds, increasing the risk of crop diseases; there is a lack of heavy metal passivation and slow-release mechanisms, and long-term use causes accumulated soil pollution; low microbial activity makes it difficult to maintain soil ecological balance.

[0004] Based on this, the present invention provides a multifunctional organic planting fertilizer and a preparation method thereof to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a multifunctional organic planting fertilizer and a preparation method thereof, so as to solve the problems mentioned in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a multifunctional organic planting fertilizer, comprising an organic base material, a heavy metal passivation system, a slow-release system, a microbial system and a function enhancement system. The organic base material comprises, by weight, 20-30 parts of decomposed sheep manure; 15-20 parts of soybean meal; and 10-15 parts of corn stalk powder.

[0008] The raw materials of the heavy metal passivation system include, by weight: 8-12 parts of attapulgite clay; 5-8 parts of humic acid; 3-5 parts of bone char;

[0009] The raw materials of the slow-release system include, by weight: 5-10 parts of phosphate rock powder; 3-6 parts of kelp residue; 2-4 parts of plant ash;

[0010] The raw materials of the microbial system include, by weight: 1-2 parts of composite microbial agent; 2-3 parts of molasses;

[0011] The functional enhancement system comprises, by weight, 4-6 parts of oyster shell powder and 1-2 parts of tobacco powder.

[0012] Preferably, the decomposed sheep manure is prepared by turning and fermenting fresh sheep manure in a high-temperature aerobic environment at 55-60° C. for 15-20 days, and the degree of decomposition is ≥90%.

[0013] Preferably, the attapulgite clay is obtained by calcining and activating natural attapulgite ore at 600-800° C. for 2 hours and then crushing the ore into 200 mesh.

[0014] Preferably, the bone char is obtained by carbonizing animal bones at a high temperature of 800-1000° C. for 4-6 hours in an oxygen-deficient environment and then crushing them into 100 mesh.

[0015] Preferably, the humic acid is prepared by extracting weathered lignite in an alkaline solution with a pH of 9-11 at 60-80° C. for 3 hours with stirring, followed by centrifugal drying.

[0016] Preferably, the composite microbial agent is prepared by mixing and culturing Bacillus subtilis, Bacillus gelatinosa and Trichoderma harzianum in a liquid fermentation tank at 30-35° C. for 48 hours and then freeze-drying.

[0017] Preferably, the oyster shell powder is prepared by calcining cleaned oyster shells at 900-1000° C. for 2 hours and grinding the shells to 150 mesh.

[0018] Preferably, the phosphate rock powder is obtained by coarsely crushing phosphate ore with a jaw crusher, wet-grinding it to 100 mesh in a ball mill, and drying and sieving it.

[0019] Based on the above organic planting fertilizer, the present invention also proposes a preparation method of a multifunctional organic planting fertilizer, comprising the following steps:

[0020] S1. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, and 10-15 parts of corn straw powder are added to a twin-shaft mixer in a weight ratio of 20-30:15-20:10-15. The mixer is operated at a low speed of 15-20 rpm for 8-10 minutes at an ambient temperature of 25-30°C and a humidity of ≤40%. Ensure that the material is uniform and free of lumps. 8-12 parts of attapulgite clay, 3-5 parts of bone char, and 5-10 parts of phosphate rock powder are added to the premixing bin by a pneumatic conveying system in a ratio of 8-12:3-5:5-10. The premixing time is 5 minutes to avoid dust.

[0021] S2. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, 10-15 parts of corn straw powder and 8-12 parts of premixed attapulgite clay, 3-5 parts of bone char, 5-10 parts of phosphate rock were added to the fermentation tank, piled 1.5-2m high, turned on the compost turning machine, controlled the temperature at 55-60 ° C, turned the compost 2-3 times a day for 7 days, and maintained the humidity at 50-55%. At the high temperature, the attapulgite clay adsorbs heavy metals, the microporous structure of bone char fixes arsenic and chromium, and humic acid simultaneously complexes free metal ions. On the fifth day of high temperature fermentation, 5-8 parts of humic acid were evenly sprinkled in a ratio of 5-8 parts, and the compost was mixed twice to promote the humification reaction.

[0022] S3. Transfer the high-temperature fermented material to a low-temperature fermentation bin, lower the temperature to 40-45°C, adjust the turning frequency to once a day for 15 days, and maintain a humidity of 45-50%. During this stage, the humic acid content increases to 12-15%. Mix 1-2 parts of a composite microbial agent with 2-3 parts of molasses in a ratio of 1-2:2-3, dilute with 10 times the amount of clean water, and activate in a constant temperature stirring tank at 30°C for 2 hours. Spray evenly onto the material surface using a high-pressure atomizing nozzle, with the spraying amount accounting for 3-5% of the total weight of the material, ensuring a bacterial colonization rate of ≥90%;

[0023] S4. 3-6 parts of kelp residue, 2-4 parts of wood ash, and 4-6 parts of oyster shell powder were added to a paddle mixer in a ratio of 3-6:2-4:4-6. The mixer was operated at 25-30 rpm for 15 minutes at a temperature of ≤35°C to avoid high temperature damage to the alginic acid in the kelp residue. Finally, 1-2 parts of tobacco powder were added and mixed for 5 minutes to disperse the insect repellent evenly into the gaps between the particles.

[0024] S5. The mixture is conveyed to a disc granulator via a belt, with a disc inclination of 45-50° and a rotation speed of 8-10 rpm. 2-3 parts of molasses solution are sprayed as a binder to control the particle size to 2-4 mm, a forming rate ≥ 85%, and a granulation humidity of 18-22%. The wet granules enter a rotary dryer to prevent inactivation of the microbial agent or volatilization of the tobacco powder.

[0025] S6. The dried granules are cooled in a countercurrent cooling tower with a cold air temperature of 15-20°C and a cooling time of 15 minutes. Once the granule temperature drops to room temperature, a double-layer vibrating screening machine is used to remove oversized or oversized granules. Qualified granules are packaged in an automatic packaging machine using aluminum-plastic composite film. The storage environment temperature is ≤30°C and the humidity is ≤60%.

[0026] Preferably, in step S5, the hot air temperature of the rotary dryer is 65-70°C, the residence time is 20-25 minutes, the outlet moisture is ≤12%, and the temperature fluctuation in the drying zone is ≤±2°C.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention achieves the synergistic passivation of heavy metals by organic base materials and mineral materials, reducing the risk of soil pollution. The slow-release system is combined with microbial metabolism to ensure a long-term and stable supply of nutrients. The functional enhancement components naturally repel insects, reducing dependence on chemical pesticides. The entire process precisely controls the degree of maturity and bacterial activity to ensure the safety and efficiency of the fertilizer. Compared with traditional fertilizers, the fertilizer of the present invention and its preparation process have the functions of ecological restoration, long-term nutrient release and biological control, are suitable for sustainable agriculture, and solve the problems existing in traditional fertilizers. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] 1. Materials:

[0031] The material components of the multifunctional organic planting fertilizer of the present invention are all commercially available unless otherwise specified.

[0032] The present invention provides a multifunctional organic planting fertilizer, comprising an organic base material, a heavy metal passivation system, a slow-release system, a microbial system and a functional enhancement system. It should be noted that the organic base material comprises, by weight, 20-30 parts of decomposed sheep manure; 15-20 parts of soybean meal; and 10-15 parts of corn stalk powder.

[0033] It should be noted that the raw materials of the heavy metal passivation system include, by weight: attapulgite clay: 8-12 parts; humic acid: 5-8 parts; bone char: 3-5 parts;

[0034] It should be noted that the raw materials of the sustained-release system include, by weight: phosphate rock: 5-10 parts; kelp residue: 3-6 parts; plant ash: 2-4 parts;

[0035] It should be noted that the raw materials of the microbial system include, by weight: composite microbial agent: 1-2 parts; molasses: 2-3 parts;

[0036] It should be noted that the raw materials of the functional enhancement system include, by weight: oyster shell powder: 4-6 parts; tobacco powder: 1-2 parts.

[0037] It should also be noted that the decomposed sheep manure is prepared by turning and fermenting fresh sheep manure in a high-temperature aerobic environment of 55-60°C for 15-20 days, with a decomposition degree of ≥90%.

[0038] It should be noted that the attapulgite clay is obtained by calcining and activating natural attapulgite ore at 600-800° C. for 2 hours and then crushing it into 200 mesh.

[0039] It should also be noted that bone char is made by carbonizing animal bones at a high temperature of 800-1000°C for 4-6 hours in an oxygen-deficient environment and then crushing them into 100 mesh.

[0040] It should be noted that humic acid is prepared by extracting weathered lignite in an alkaline solution of pH 9-11 at 60-80° C. for 3 hours with stirring, followed by centrifugal drying.

[0041] It should be noted that the composite microbial agent is prepared by mixing and culturing Bacillus subtilis, Bacillus gelatinosa and Trichoderma harzianum in a liquid fermentation tank at 30-35°C for 48 hours and then freeze-drying.

[0042] It should be noted that the oyster shell powder is prepared by calcining cleaned oyster shells at 900-1000°C for 2 hours and grinding them to 150 mesh.

[0043] Among them, it should be noted that phosphate rock powder is obtained by coarsely crushing phosphate ore with a jaw crusher, wet grinding it in a ball mill to 100 mesh, and then drying and sieving it.

[0044] 2. Process:

[0045] Based on the above organic planting fertilizer, the present invention also proposes a preparation method of a multifunctional organic planting fertilizer, comprising the following steps:

[0046] S1. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, and 10-15 parts of corn straw powder are added to a twin-shaft mixer in a weight ratio of 20-30:15-20:10-15. The mixer is operated at a low speed of 15-20 rpm for 8-10 minutes at an ambient temperature of 25-30°C and a humidity of ≤40%. Ensure that the material is uniform and free of lumps. 8-12 parts of attapulgite clay, 3-5 parts of bone char, and 5-10 parts of phosphate rock powder are added to the premixing bin by a pneumatic conveying system in a ratio of 8-12:3-5:5-10. The premixing time is 5 minutes to avoid dust.

[0047] S2. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, 10-15 parts of corn straw powder and 8-12 parts of premixed attapulgite clay, 3-5 parts of bone char, 5-10 parts of phosphate rock were added to the fermentation tank, piled 1.5-2m high, turned on the compost turning machine, controlled the temperature at 55-60 ° C, turned the compost 2-3 times a day for 7 days, and maintained the humidity at 50-55%. At the high temperature, the attapulgite clay adsorbs heavy metals, the microporous structure of bone char fixes arsenic and chromium, and humic acid simultaneously complexes free metal ions. On the fifth day of high temperature fermentation, 5-8 parts of humic acid were evenly sprinkled in a ratio of 5-8 parts, and the compost was mixed twice to promote the humification reaction.

[0048] S3. Transfer the high-temperature fermented material to a low-temperature fermentation bin, lower the temperature to 40-45°C, adjust the turning frequency to once a day for 15 days, and maintain a humidity of 45-50%. During this stage, the humic acid content increases to 12-15%. Mix 1-2 parts of a composite microbial agent with 2-3 parts of molasses in a ratio of 1-2:2-3, dilute with 10 times the amount of clean water, and activate in a constant temperature stirring tank at 30°C for 2 hours. Spray evenly onto the material surface using a high-pressure atomizing nozzle, with the spraying amount accounting for 3-5% of the total weight of the material, ensuring a bacterial colonization rate of ≥90%;

[0049] S4. 3-6 parts of kelp residue, 2-4 parts of wood ash, and 4-6 parts of oyster shell powder were added to a paddle mixer in a ratio of 3-6:2-4:4-6. The mixer was operated at 25-30 rpm for 15 minutes at a temperature of ≤35°C to avoid high temperature damage to the alginic acid in the kelp residue. Finally, 1-2 parts of tobacco powder were added and mixed for 5 minutes to disperse the insect repellent evenly into the gaps between the particles.

[0050] S5. The mixture is conveyed to a disc granulator via a belt, with a disc inclination of 45-50° and a rotation speed of 8-10 rpm. 2-3 parts of molasses solution are sprayed as a binder to control the particle size to 2-4 mm, a forming rate ≥ 85%, and a granulation humidity of 18-22%. The wet granules enter a rotary dryer to prevent inactivation of the microbial agent or volatilization of the tobacco powder.

[0051] S6. The dried granules are cooled in a countercurrent cooling tower with a cold air temperature of 15-20°C and a cooling time of 15 minutes. Once the granule temperature drops to room temperature, a double-layer vibrating screening machine is used to remove oversized or oversized granules. Qualified granules are packaged in an automatic packaging machine using aluminum-plastic composite film. The storage environment temperature is ≤30°C and the humidity is ≤60%.

[0052] It should also be noted that in step S5, the hot air temperature of the rotary dryer is 65-70°C, the residence time is 20-25 minutes, the outlet moisture is ≤12%, and the temperature fluctuation in the drying zone is ≤±2°C.

[0053] Example 1: In this example, a method for preparing a multifunctional organic fertilizer comprises the following steps:

[0054] S1: 25 parts of decomposed sheep manure, 18 parts of soybean meal, and 12 parts of corn straw powder were placed in a twin-shaft mixer and operated at 18 rpm for 9 minutes in an ambient temperature of 28°C and a humidity of 35%. 10 parts of attapulgite clay, 4 parts of bone char, and 8 parts of phosphate rock powder were premixed by pneumatic conveying for 5 minutes.

[0055] S2: The mixed material was piled up to 1.8m high and turned twice a day by a compost turner. The temperature was 58°C and the humidity was 52% for 7 days. On the 5th day, 6 parts of humic acid were added and the compost was turned and mixed twice.

[0056] S3: Low-temperature fermentation at 42°C, turning the compost once a day, 48% humidity, for 15 days; spraying with a dilution of 1.5 parts of composite microbial agent and 2.5 parts of molasses at a spray rate of 4%;

[0057] S4: Mix 4 parts of kelp residue, 3 parts of wood ash, and 5 parts of oyster shell powder for 15 minutes at 33°C; add 1.5 parts of tobacco powder and mix for 5 minutes;

[0058] S5: disc granulator with an inclination of 48°, a rotation speed of 9 rpm, and a spraying of 2.5 parts of molasses solution; dryer hot air temperature of 68°C, residence time of 23 minutes, and outlet moisture of 11%;

[0059] S6: Cooling temperature 18℃, qualified rate after screening 96%, packaging storage temperature 28℃, humidity 55%.

[0060] Example 2: In this example, the amount of decomposed sheep manure is 20 parts, the amount of attapulgite clay is 8 parts, and the amount of bone char is 3 parts. Other process parameters are the same as those in Example 1.

[0061] Example 3: In this example, the amount of decomposed sheep manure is 30 parts, the amount of attapulgite clay is 12 parts, and the amount of bone char is 5 parts. Other process parameters are the same as those in Example 1.

[0062] Example 4: In this example, phosphate rock powder is 5 parts, kelp residue is 3 parts, and other process parameters are the same as in Example 1;

[0063] Example 5: In this example, the composite microbial agent is 2 parts, the tobacco powder is 2 parts, and the other process parameters are the same as those in Example 1;

[0064] The component parameters in Examples 1 to 5 are recorded as shown in Table 1:

[0065] Table 1: Example material composition table

[0066]

[0067]

[0068] Comparative Example 1: In this comparative example, the amount of decomposed sheep manure was 35 parts (exceeding the upper limit of the range), and the other process parameters were the same as those in Example 1;

[0069] Comparative Example 2: In this comparative example, the soybean meal was 25 parts (exceeding the upper limit of the range), and the other process parameters were the same as those in Example 1;

[0070] Comparative Example 3: In this comparative example, the amount of corn stalk shreds was 20 parts (exceeding the upper limit of the range), and the other process parameters were the same as those in Example 1;

[0071] Comparative Example 4: In this comparative example, the amount of attapulgite clay was 15 parts (exceeding the upper limit of the range), and the other process parameters were the same as those in Example 1;

[0072] Comparative Example 5: In this comparative example, the amount of bone char was 1 part (exceeding the lower limit of the interval), and the other process parameters were the same as those in Example 1;

[0073] The component parameters of Comparative Examples 1 to 5 are recorded as shown in Table 2:

[0074] Table 2: Comparative Example Material Composition Table

[0075]

[0076]

[0077] 3. Performance test:

[0078] Fertilizer samples were prepared according to the preparation methods and parameters of the embodiments and comparative examples, and performance tests were performed on the fertilizer samples. The steps are as follows:

[0079] a. Heavy metal passivation rate test:

[0080] a1. Sample preparation: 10 g of fertilizer sample was digested with a nitric acid-hydrofluoric acid mixture by microwave;

[0081] a2. Heavy metal extraction: Extract available heavy metals using the DTPA extraction method according to the "Method for Extraction of Available Heavy Metals in Soil Quality" (HJ803-2016);

[0082] a3. Detection and analysis: Atomic absorption spectrometry (AAS) or inductively coupled plasma mass spectrometry (ICP-MS) to determine cadmium (Cd), lead (Pb), and arsenic (As) content;

[0083] Passivation rate (%) = (original soil available heavy metal content - available content after application) / original content × 100%, required to be ≥85%;

[0084] b. Nutrient slow-release performance test:

[0085] b1. Static extraction: 5 g of fertilizer granules were placed in deionized water (solid-to-liquid ratio 1:10) and shaken at a constant temperature of 25°C. Samples were taken at 1, 7, 14, and 28 days.

[0086] b2. Nutrient determination:

[0087] Nitrogen: Kjeldahl method (GB / T8572-2010);

[0088] Phosphorus: Molybdenum Antimony Anti-Spectrophotometry (NY / T2421-2013);

[0089] Potassium: flame photometry (NY / T2540-2014);

[0090] Cumulative release rate over 28 days: nitrogen ≥60%, phosphorus ≥40%, potassium ≥70% (refer to NY / T525-2021);

[0091] c. Microbial activity test:

[0092] c1. Colony count: Take 1 g of fertilizer sample, dilute it serially, and spread it on LB medium. Incubate at 30°C for 48 hours and count the number of viable bacteria.

[0093] c2. Antibacterial effect: Co-culture Trichoderma with common pathogens (such as Fusarium) and measure the diameter of the inhibition zone;

[0094] Standard: viable bacteria survival rate ≥ 85%, Trichoderma inhibition zone diameter ≥ 15 mm;

[0095] d. Anti-insect effect test:

[0096] d1. Indoor simulation: Evenly spread fertilizer in a culture dish, introduce 100 nematodes (e.g., root-knot nematodes), and incubate at 25°C for 72 hours.

[0097] d2. Calculation of inhibition rate: Calculate the nematode mortality or activity inhibition rate;

[0098] Standard: Nematode inhibition rate ≥ 80% (compared to the blank control group);

[0099] e. Safety testing:

[0100] e1. Seed germination test: Dilute the fertilizer extract at a ratio of 1:10, soak filter paper, and place radish seeds on it. Incubate at 25°C for 5 days.

[0101] e2. Germination index (GI): calculation of germination rate and root length ratio;

[0102] Standard: germination index ≥ 80% (GI = germination rate of treatment group × root length / germination rate of control group × root length × 100%);

[0103] The performance parameters of the fertilizer samples prepared in Examples 1 to 5 are recorded in Table 3:

[0104] Table 3: Example performance data

[0105]

[0106]

[0107] The performance parameters of the fertilizer samples prepared in Comparative Examples 1 to 5 are recorded, as shown in Table 4:

[0108] Table 4: Comparative Example Performance Data

[0109] Performance indicators Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Heavy metal passivation rate (%) 75 82 78 70 68 Nitrogen release rate (28 days) 55 72 58 62 50 Phosphorus release rate (28 days) 28 40 30 32 25 Microbial survival rate (%) 80 85 82 78 75 Anti-insect effect (inhibition rate) 70 75 72 65 60

[0110] 4. Analysis Conclusions:

[0111] In the example, 8-12 parts of attapulgite clay and 3-5 parts of bone char synergistically adsorbed heavy metals, with a passivation rate of ≥85%. In the comparative example, the passivation rate dropped to 70% due to excessive minerals squeezing the pores. In Example 1, 8 parts of phosphate rock powder and 3 parts of wood ash were matched for sustained release, resulting in a phosphorus release rate of 45%. In Comparative Example 5, 1 part of bone char failed to stabilize arsenic, resulting in a phosphorus release rate of only 25%. In Example 1, 1.5 parts of the microbial agent and 2.5 parts of molasses provided sufficient carbon and nitrogen sources, resulting in a survival rate of 93%. In Comparative Example 1, excessive sheep manure led to a C / N imbalance, and the survival rate dropped to 80%.

[0112] Furthermore, in the fertilizer sample prepared in Example 1, 25 parts of decomposed sheep manure and 18 parts of soybean meal provide a balanced nitrogen source, 10 parts of attapulgite clay and 4 parts of bone char form an efficient passivation network, 2.5 parts of molasses as a binder and precise temperature control at 68°C for drying ensure the particle forming rate (≥85%) and microbial activity (survival rate 93%), the heavy metal passivation rate is 92%, the nitrogen and phosphorus release rate is 68% / 45%, and the insect repellent inhibition rate is 85%, all of which are higher than those of other embodiments and comparative examples. Therefore, Example 1 is the best embodiment of the present invention due to its scientific proportion and process synergy.

[0113] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0114] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A multifunctional organic planting fertilizer, comprising an organic base material, a heavy metal passivation system, a slow-release system, a microbial system and a function enhancement system, characterized in that: The organic base material comprises, by weight, 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, and 10-15 parts of corn stalks. The raw materials of the heavy metal passivation system include, by weight: 8-12 parts of attapulgite clay; 5-8 parts of humic acid; 3-5 parts of bone char; The raw materials of the slow-release system include, by weight: 5-10 parts of phosphate rock powder; 3-6 parts of kelp residue; 2-4 parts of plant ash; The raw materials of the microbial system include, by weight: 1-2 parts of composite microbial agent; 2-3 parts of molasses; The functional enhancement system comprises, by weight, 4-6 parts of oyster shell powder and 1-2 parts of tobacco powder.

2. A multifunctional organic planting fertilizer according to claim 1, characterized in that, The decomposed sheep manure is prepared by turning and fermenting fresh sheep manure in a high-temperature aerobic environment of 55-60° C. for 15-20 days, and the degree of decomposition is ≥90%.

3. A multifunctional organic planting fertilizer according to claim 2, characterized in that, The attapulgite clay is prepared by calcining and activating natural attapulgite ore at 600-800° C. for 2 hours and then crushing the ore into 200 meshes.

4. The multifunctional organic planting fertilizer according to claim 1, characterized in that: The bone char is obtained by carbonizing animal bones at a high temperature of 800-1000° C. for 4-6 hours in an oxygen-deficient environment and then crushing them into 100 mesh.

5. The multifunctional organic planting fertilizer according to claim 4, characterized in that: The humic acid is prepared by extracting weathered lignite in an alkaline solution at pH 9-11 at 60-80° C. for 3 hours through stirring, and then centrifugally drying.

6. The multifunctional organic planting fertilizer according to claim 4, characterized in that: The composite microbial agent is prepared by mixing and culturing Bacillus subtilis, Bacillus jelly-like and Trichoderma harzianum in a liquid fermentation tank at 30-35 DEG C for 48 hours and then freeze-drying.

7. The multifunctional organic planting fertilizer according to claim 1, characterized in that: The oyster shell powder is prepared by calcining cleaned oyster shells at 900-1000° C. for 2 hours and grinding the shells to 150 meshes.

8. The multifunctional organic planting fertilizer according to claim 1, characterized in that: The phosphate rock powder is obtained by coarsely crushing phosphate ore with a jaw crusher, wet-grinding it to 100 mesh in a ball mill, and drying and sieving it.

9. The method for preparing a multifunctional organic planting fertilizer according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, and 10-15 parts of corn straw powder are added to a twin-shaft mixer in a weight ratio of 20-30:15-20:10-15. The mixer is operated at a low speed of 15-20 rpm for 8-10 minutes at an ambient temperature of 25-30°C and a humidity of ≤40%. Ensure that the material is uniform and free of lumps. 8-12 parts of attapulgite clay, 3-5 parts of bone char, and 5-10 parts of phosphate rock powder are added to the premixing bin in a ratio of 8-12:3-5:5-10 by a pneumatic conveying system. The premixing time is 5 minutes to avoid dust. S2. 20-30 parts of decomposed sheep manure, 15-20 parts of soybean meal, 10-15 parts of corn straw powder and 8-12 parts of premixed attapulgite clay, 3-5 parts of bone char, 5-10 parts of phosphate rock were added to the fermentation tank, piled 1.5-2m high, turned on the compost turning machine, controlled the temperature at 55-60 ° C, turned the compost 2-3 times a day for 7 days, and maintained the humidity at 50-55%. At the high temperature, the attapulgite clay adsorbs heavy metals, the microporous structure of bone char fixes arsenic and chromium, and humic acid simultaneously complexes free metal ions. On the fifth day of high temperature fermentation, 5-8 parts of humic acid were evenly sprinkled in a ratio of 5-8 parts, and the compost was mixed twice to promote the humification reaction. S3. Transfer the high-temperature fermented material to a low-temperature fermentation bin, lower the temperature to 40-45°C, adjust the turning frequency to once a day for 15 days, and maintain a humidity of 45-50%. During this stage, the humic acid content increases to 12-15%. Mix 1-2 parts of a composite microbial agent with 2-3 parts of molasses in a ratio of 1-2:2-3, dilute with 10 times the amount of clean water, and activate in a constant temperature stirring tank at 30°C for 2 hours. Spray evenly onto the material surface using a high-pressure atomizing nozzle, with the spraying amount accounting for 3-5% of the total weight of the material, ensuring a bacterial colonization rate of ≥90%; S4. 3-6 parts of kelp residue, 2-4 parts of wood ash, and 4-6 parts of oyster shell powder were added to a paddle mixer in a ratio of 3-6:2-4:4-6. The mixer was operated at 25-30 rpm for 15 minutes at a temperature of ≤35°C to avoid high temperature damage to the alginic acid in the kelp residue. Finally, 1-2 parts of tobacco powder were added and mixed for 5 minutes to disperse the insect repellent evenly into the gaps between the particles. S5. The mixture is conveyed to a disc granulator via a belt, with a disc inclination of 45-50° and a rotation speed of 8-10 rpm. 2-3 parts of molasses solution are sprayed as a binder to control the particle size to 2-4 mm, a forming rate ≥ 85%, and a granulation humidity of 18-22%. The wet granules enter a rotary dryer to prevent inactivation of the microbial agent or volatilization of the tobacco powder. S6. The dried granules are cooled in a countercurrent cooling tower with a cold air temperature of 15-20°C and a cooling time of 15 minutes. Once the granule temperature drops to room temperature, a double-layer vibrating screening machine is used to remove oversized or oversized granules. Qualified granules are packaged in an automatic packaging machine using aluminum-plastic composite film. The storage environment temperature is ≤30°C and the humidity is ≤60%.

10. The method for preparing a multifunctional organic planting fertilizer according to claim 9, characterized in that: In step S5, the hot air temperature of the rotary dryer is 65-70° C., the residence time is 20-25 minutes, the outlet moisture is ≤12%, and the temperature fluctuation in the drying zone is ≤±2° C.

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