Preparation method of metal ion activated soil indigenous enzyme bacterium composition

Abstract

The invention relates to a preparation method of a metal ion activated soil indigenous enzyme bacterium composition, and belongs to the field of agricultural microbial technologies and novel fertilizers, the composition is prepared from a powder water-soluble fertilizer with the zinc content of 10.0-20.0% and a special activator accounting for 0.5-1.0% of the total mass of the composition through a low-temperature chelation compounding process. Through the triple mechanisms of zinc nutrition starting, activating agent biological regulation and control and slow release synergy, soil aboriginal beneficial microbial communities can be efficiently and directionally activated and optimized, soil enzyme activity and microbial biomass are remarkably improved, continuous cropping obstacle soil is improved, crop stress resistance is effectively enhanced, growth is promoted, and finally yield increase and quality improvement of crops are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural microbial technology and new fertilizer technology, in particular to a preparation method of a metal ion activated soil indigenous enzyme bacteria composition. BACKGROUND

[0002] Soil is the core of the agricultural ecosystem, and its health directly relates to the sustainability of crop yield and quality. However, in intensive agricultural production, due to long-term continuous cropping, overuse of chemical fertilizers and pesticides, the soil micro-ecology is generally imbalanced, specifically manifested in the decline of beneficial microbial communities, the decrease of soil enzyme activity, the frequent occurrence of soil-borne diseases, and the blockage of nutrient cycling. To cope with soil degradation, the existing technology mainly develops along two paths: one is to correct plant nutrient deficiency by applying trace element fertilizers (such as zinc fertilizer), which can directly promote crop growth, but often ignores the maintenance and activation of the soil microbial system, and only treats the symptoms; the other is to directly apply exogenous microbial inoculants to supplement soil beneficial bacteria, but the strains in such products are easily inhibited by the soil environment, with low colonization success rate, unstable effect and high cost. Therefore, how to economically, efficiently and durably stimulate the functional activity of the soil's own microbial community (i.e. indigenous enzyme bacteria) has become a key challenge in the field of soil health management.

[0003] Zinc (Zn) is an essential trace element for plants, which is known to participate in auxin synthesis, act as a variety of enzyme activators and enhance stress resistance in plants. The application of traditional zinc-containing water-soluble fertilizers mainly focuses on correcting crop zinc deficiency symptoms through foliar spraying or root irrigation. Although some studies have shown that zinc has a certain effect on microbial enzyme activity, there is still a lack of a systematic product development scheme in the existing technology that can combine specific forms and contents of zinc sources with special biological activators and achieve stable compounding through specific processes, thereby synergistically acting on the soil-microbe-plant system. Specifically, the existing technology fails to effectively utilize the "nutrient starting" value of zinc and the "biological regulation" function of the activator, and even less realizes long-term synergy of the two in the soil through process innovation, thereby failing to achieve the goal of activating indigenous microbial communities from the root and systematically improving soil micro-ecology. The present application is proposed in view of the above deficiencies of the existing technology. SUMMARY

[0004] The present application provides a preparation method of a metal ion activated soil indigenous enzyme bacteria composition to solve the problems of the prior art.

[0005] To solve the above technical problems, the present application is realized by the following technical scheme: a preparation method of a metal ion activated soil indigenous enzyme bacteria composition, comprising the following steps:

[0006] S1: providing a powder water-soluble fertilizer containing zinc element, the content of which is not less than 10.0%;

[0007] S2: compounding the powder water-soluble fertilizer with an activating agent to obtain an activating agent compound;

[0008] S3: applying the activating agent compound to the soil to activate indigenous enzyme bacteria in the soil. In a specific embodiment, the content of zinc in the powder water-soluble fertilizer is 10.0% to 20.0%.

[0009] In a specific embodiment, the content of zinc in the powder water-soluble fertilizer is 15% to 20%.

[0010] In a specific embodiment, the amount of the activating agent added in the compound is 0.5% to 1% of the total mass of the powder water-soluble fertilizer.

[0011] In a specific embodiment, the powder water-soluble fertilizer and the activating agent are integrated and compounded under low-temperature conditions.

[0012] In a specific embodiment, it further includes detecting the content of zinc in the soil before application, and adjusting the application amount of the activating agent compound according to the detection result.

[0013] In a specific embodiment, the application mode includes at least one of soil base application, foliar spraying, or drip irrigation.

[0014] In a specific embodiment, when soil base application is adopted, the activating agent compound is compounded and applied with organic fertilizer, and the amount of the organic fertilizer is 2 to 3 tons per mu.

[0015] In a specific embodiment, the activating agent compound is suitable for zinc-deficient soil or continuous cropping obstacle soil.

[0016] The beneficial effects of the present application are:

[0017] 1. By low-temperature chelation of a specific high-content zinc (Zn) powder water-soluble fertilizer with a precise amount of special activator, a significant synergistic effect is produced. The core benefit is that it breaks through the single functional limitation of traditional zinc fertilizer as a plant nutrient supplement and creates a new model for actively and directionally regulating soil microbial communities through nutritional chemical pathways. Specifically, the invention realizes the effective integration of the "nutrient activation", "biological regulation" and "slow-release synergy" triple mechanisms: zinc directly and efficiently enhances the basic activity of the soil enzyme system, creating an energy-rich environment for microbial metabolism; the special activator acts as a "biological signal" and "metabolic promoter" to selectively enrich and activate inherent beneficial indigenous enzymes and bacteria in the soil (such as phosphorus-dissolving bacteria, nitrogen-fixing bacteria, and biocontrol bacteria), guiding the succession of microbial communities towards functional optimization; and the unique low-temperature chelation process ensures the formation of stable complexes of zinc and activator, achieving simultaneous slow release and long-term effects of both in the soil. This systematic activation method enhances the self-regulation and functional recovery capacity of the soil ecosystem from the root source;

[0018] 2. In terms of soil health, it can significantly and continuously enhance the activity of key enzymes such as dehydrogenase, urease, and phosphatase, increase microbial biomass carbon, and optimize microbial community structure, thereby effectively improving continuous cropping obstacle soils, relieving soil-borne disease pressure, and enhancing soil fertility and buffering performance. Secondly, in terms of crop growth, it not only can quickly correct and prevent crop zinc deficiency symptoms, promote root development and plant robust growth, but also can induce systemic resistance in crops through activated rhizosphere beneficial bacteria, enhancing their resistance to drought, low temperature, and biological stress. Finally, in terms of output and quality, the invention can stably increase crop yield and improve agricultural product quality, such as increasing grain weight, enhancing fruit flavor and nutritional value, providing an innovative and practical technical support for achieving green, high-yield, high-quality, and sustainable development of agriculture. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0020] A preparation method of a metal ion activated soil indigenous enzyme and bacteria composition.

[0021] The composition is made by low-temperature chelation compounding process with a specific high-content zinc (Zn) powder water-soluble fertilizer and a special activator in precise proportion. The composition does not directly inoculate bacteria, but through the dual mechanism of "deficiency correction (Zn) + microbial regulation (activator)", it stimulates the activity and function of soil indigenous enzyme bacteria.

[0022] The preparation method of the above-mentioned composition is that the powder water-soluble fertilizer with a zinc content of 10.0% to 20.0% (preferably 15%-20%) is mixed with the activator accounting for 0.5% to 1.0% of the total mass of the final composition under low-temperature (for example, 5-25℃) conditions to carry out sufficient mixing and chelation reaction to form a stable complex, ensuring the effectiveness of the synergistic effect of zinc and the activator.

[0023] The application method of the above-mentioned composition can flexibly adopt soil base application, foliar spraying or drip irrigation flushing according to the soil condition and crop demand to accurately regulate the soil micro-ecology.

[0024] Zinc is an essential cofactor or structural component of various enzymes in the soil (such as dehydrogenase, phosphatase, urease). The present application provides high-effective and mobile zinc ions (Zn 2+ ), which can directly supplement the key metal cofactor of the soil enzyme system and rapidly improve the overall enzyme activity of the soil. This creates a "nutrient start" environment for the metabolic activity of indigenous microbial communities.

[0025] The activator contains components that can stimulate microbial growth and metabolism, promote biofilm formation, or act as signal molecules for specific microbial populations (such as specific organic acids, polysaccharides, or biological stimulants). It does not directly kill or inoculate bacteria, but as an "information substance" and "metabolic promoter", it selectively enriches and activates the inherent and beneficial indigenous enzyme bacteria in the soil (such as phosphorus-dissolving bacteria, nitrogen-fixing bacteria, and biocontrol bacteria), guiding the succession of microbial communities towards a more optimized function.

[0026] Through low-temperature chelation compounding process, zinc ions form stable organic-inorganic complexes with active groups in the activator, which have moderate slow-release properties. This process is crucial, and its advantages are: protection of activity: low temperature avoids the degradation of heat-sensitive bioactive substances in the activator. Slow-release synergy: the chelation structure allows zinc and the activator to be released slowly and synchronously in the soil, prolonging the action time and achieving precise matching of "nutrient supply" and "biological stimulation" in space and time, continuously guiding microbial activity. Improve efficiency: stable complexes reduce soil fixation of zinc and ineffective consumption of activators, allowing more effective components to act on target microorganisms.

[0027] Example 1: Standard preparation of core formula

[0028] This example prepares the most core and preferred composition of the present application.

[0029] Raw material preparation:

[0030] Powdered water-soluble fertilizer: 1000 kg of trace element water-soluble fertilizer with a zinc (Zn) content of 16.14% (according to test report No: F253506) was used. The fertilizer met the standard of NY / T 1974-2010 Determination of Copper, Iron, Manganese, Zinc, Boron, and Molybdenum Content in Water-Soluble Fertilizers, and the product form was uniform dry powder without caking. This content point is within the range of 10.0%-20.0% claimed in the present application, and is close to the upper limit of the preferred range of 15%-20%, having significant nutritional starting potential.

[0031] Special activator: 7.5 kg of composite biological activator was weighed. The activator was a dark brown powder, and the main active ingredients included potassium humate (providing chelating and stimulating groups such as carboxyl, phenolic hydroxyl), seaweed extract (rich in betaine, algal plant hormones, and polysaccharides), and trace amino acid complexes (such as glycine, glutamic acid). The total amount of activator accounted for about 0.75% of the total mass of the final composition (1000 kg + 7.5 kg = 1007.5 kg), falling exactly within the preferred range of 0.5%-1.0%.

[0032] Premixing and cooling: The jacket of the mixing machine (a double helix conical mixer was recommended) was connected to circulating cooling water to pre-cool the mixing chamber to a temperature of 10±2°C. All the powdered water-soluble fertilizer was first put into the mixing machine, and the machine was run at a low speed (10-15 revolutions per minute).

[0033] Low-temperature chelation and compounding:

[0034] Under continuous low-temperature and slow stirring, 7.5 kg of activator powder was uniformly and slowly (taking about 15-20 minutes) sprinkled into the fertilizer through a precision feeder. This process aimed to avoid local overheating and dust, and to ensure uniform preliminary mixing.

[0035] After the feeding was completed, the stirring speed was adjusted to 20-25 revolutions per minute, and the temperature of the mixing chamber was maintained within the range of 10-15°C. The mixing and stirring were continued for 3 hours under this condition. This "low-temperature maintenance period" was a critical stage for the chelation reaction to occur. Under the dispersion action of mechanical force, zinc ions (Zn 2+ ) were gradually dissolved and released from the fertilizer particles, and coordinated with the functional groups such as carboxyl (-COOH) and phenolic hydroxyl (-OH) on the molecular chains of the activator humic acid and alginic acid, forming stable organic-inorganic complex (chelation) structures. The low-temperature environment effectively inhibited the decomposition of heat-sensitive biological stimulants (such as certain vitamins and hormone substances) in the activator, preserving their biological activity.

[0036] Homogenization and discharging: after 3 hours, stop stirring and sample to check the homogeneity (coefficient of variation CV≤5% is qualified). After qualification, slowly raise the temperature in the mixer to room temperature (about 25°C) and discharge. The product is a dry powder with uniform color, grayish brown, good flowability, and no visible separation of raw materials.

[0037] Product identification and packaging: seal the product in a film-coated woven bag, mark the general name of the product (such as: water-soluble fertilizer containing activator type trace elements), technical index (Zn+activator), record number (derivative number of WLSRXZ2025-00003), production date, and "low-temperature chelation process" mark.

[0038] Example 2: Preparation of a low-zinc content formula

[0039] This example illustrates the preparation of a composition with zinc content near the lower limit.

[0040] Raw materials: 1000 kg of a water-soluble fertilizer powder with a zinc content of 10.5%. The activator is the same as in Example 1, and 5.0 kg (0.5% of the total mass of the final product) is weighed.

[0041] Process: The preparation process is the same as in Example 1, but the low-temperature mixing temperature is controlled at 8-12°C, and the mixing time is extended to 3.5 hours. Due to the low zinc content, the relative total zinc amount is reduced, and to ensure a higher probability of effective contact and chelation between each zinc ion and the activator, the reaction time needs to be slightly extended to ensure complete integration.

[0042] Product characteristics: This formula is suitable for crops that are slightly zinc-deficient or sensitive to zinc in the soil, aiming to provide basic zinc nutrition and activate microbial activity, with relatively low cost.

[0043] Example 3: Preparation of a high-zinc content formula

[0044] This example illustrates the preparation of a composition with zinc content near the upper limit.

[0045] Raw materials: 1000 kg of a water-soluble fertilizer powder with a zinc content of 19.2%. The activator is the same as in Example 1, and 10.0 kg (about 1.0% of the total mass of the final product) is weighed.

[0046] Process: The preparation process is the same as in Example 1, with a low-temperature mixing temperature controlled at 12-18°C. Due to the high zinc concentration, the ion release dynamics are strong, and the reaction with the activator may be more intense. A slightly higher temperature range and a 1.0% activator addition are used to provide enough chelation sites and avoid the rapid fixation of some free zinc ions in the soil due to incomplete chelation. The mixing time is 2.5 hours.

[0047] Product properties: The formulation has very strong zinc supply capacity, and is suitable for crops with high zinc demand (such as corn) in severely zinc-deficient soils or as a rapid repair starter in severely degraded soil areas.

[0048] Example 4: Preparation by changing the addition method of the activator

[0049] This example investigates the effect of the form of the activator on the process.

[0050] Raw materials: 1000 kg of powder water-soluble fertilizer (Zn 16.14%). The activator is a liquid concentrate formulation (active ingredients equivalent to the powder activator of Example 1), with a total amount of 7.5 kg of dry matter.

[0051] Process:

[0052] Dilute the liquid activator with 5 times the mass of cold water (5-10°C) to make a dilute solution.

[0053] Place the powder water-soluble fertilizer in a fluidized bed or high-speed shear mixer, and under continuous cooling (maintain the material temperature <20°C), uniformly spray the activator dilute solution through an atomizing nozzle onto the fertilizer powder in a rolling state.

[0054] After spraying is complete, continue to mix and dry under low-temperature ventilation conditions for 1-2 hours until the material returns to a powder state.

[0055] Product properties: Liquid-solid mixing allows the activator to be more uniformly coated on the surface of the fertilizer particles, with a large initial contact area, which may shorten the chelation reaction time. However, it is necessary to control the spraying speed and drying conditions to prevent caking. This method is suitable for production under specific equipment conditions.

[0056] Composition application examples

[0057] This part of the examples describes the specific schemes for applying the above-prepared composition to different crops, different soil conditions, and different application methods.

[0058] Example 5: Basal application in rice field soil (for southern acidic zinc-deficient rice fields)

[0059] Background: The pH value of southern rice field soil is relatively low (pH 5.0-6.0), and although the zinc availability is relatively high, due to long-term flooding, zinc is prone to migration or reduction reactions leading to "potential zinc deficiency", and continuous cropping leads to a decrease in soil biological activity.

[0060] Soil testing: Take the plough layer soil before sowing, and measure the available zinc (DTPA extraction) content to be 0.8 mg / kg, which is lower than the critical value (1.0 mg / kg); the soil microbial biomass carbon is low.

[0061] Formulation: Soil application. The composition prepared in Example 1 is selected. Since the soil is moderately deficient in zinc, the target amount is set to provide 2.0 kg pure zinc per mu.

[0062] Calculation and mixing of fertilizer:

[0063] Required amount of composition = target amount of pure zinc / zinc content of composition = 2.0 kg / 16.14% ≈ 12.4 kg per mu.

[0064] The 12.4 kg of composition is pre-mixed with 1500 kg (about 1.5 tons per mu) of well-rotted farmyard manure or commercial organic fertilizer at the field head. The addition of organic fertilizer not only provides comprehensive nutrition, but its organic matter itself is a carbon source for microorganisms, producing synergy with the composition of the present application.

[0065] Application: Before the last plowing and harrowing of the rice field, the mixed fertilizer is uniformly spread over the entire field, and then plowed into the 15-20 cm deep soil layer. After harrowing, seeding or transplanting can be done.

[0066] Expected mechanism of action and effects:

[0067] Mechanism: The composition enters the soil layer with alternating anaerobic / aerobic conditions along with the organic fertilizer. The addition of zinc directly enhances the potential activity of soil enzymes (such as urease involved in the conversion of organic nitrogen). The activator is slowly released in moist soil, stimulating the metabolism of indigenous microorganisms (including anaerobic and facultative anaerobic bacteria), promoting the humification process of organic fertilizer, and possibly enriching nitrogen-fixing bacteria, silicate bacteria, and other beneficial microorganisms in the rhizosphere of rice.

[0068] Effects: It is expected that the rice will have fast regreening after transplanting, more white roots and deep penetration of roots at the early tillering stage. The soil oxidation-reduction potential is improved at the medium stage, reducing the toxicity of harmful substances such as hydrogen sulfide. The functional leaves remain green after heading, resulting in an increase in effective panicle number, thousand-grain weight, and yield improvement of 8-15%, and possibly an improvement in rice quality (such as zinc content).

[0069] Example 6: Corn drip irrigation topdressing (for northwest continuous corn problem area)

[0070] Background: In the northwest irrigated agricultural area, corn has been continuously planted for a long time, and the soil is rich in phosphorus and potassium but zinc is fixed, the microbial community is monotonous, and the risk of soil-borne diseases increases.

[0071] Soil testing: Before the big bell stage, the root zone soil available zinc is 0.6 mg / kg (severe zinc deficiency), and the soil phosphatase activity is high but the diversity index is low.

[0072] Formulation: Drip irrigation flush application, topdressing twice at the big bell stage and the tasseling stage. The composition of Example 3 (high zinc and high activator) is selected to quickly correct zinc deficiency and strongly regulate the rhizosphere microorganisms.

[0073] Application operation:

[0074] First time (big trumpet period): 3.0 kg of the composition per mu. Dissolve in the drip irrigation system in the fertilizer tank, irrigate with water for 2-3 hours. Ensure that the irrigation wet front reaches the main root layer.

[0075] Second time (tasseling period): 2.0 kg of the composition per mu, same operation as before.

[0076] The whole process is combined with conventional nitrogen, potassium drip irrigation fertilizer, but the phosphorus fertilizer is appropriately reduced.

[0077] Expected mechanism of action and effect:

[0078] Mechanism: Water-soluble composition is delivered directly to the corn rhizosphere dense area through drip irrigation. High concentration of zinc quickly meets the rapid growth of crops zinc demand, while "cleaning" the root surface, improving the rhizosphere micro-environment. Activators act like "signal bombs" in the rhizosphere, a hot spot for microorganisms, to stimulate the growth of beneficial bacteria (such as Pseudomonas and Bacillus) that can produce siderophores, antibiotics or induce systemic resistance, and build a healthy rhizosphere microbial barrier.

[0079] Effect: It is expected that the corn stem will be thickened, the leaf spread will be good, and the photosynthetic efficiency will be improved. It can effectively reduce the occurrence of soil-borne diseases such as large spot and stem base rot. The grain is plump, the bare tip is reduced, the yield is increased by 10-20%, and the drought resistance is improved.

[0080] Example 7: Foliar spraying of facility vegetables (for wintering cucumber zinc absorption disorder)

[0081] Background: Low temperature and weak light in winter facility greenhouse, poor root activity of cucumber, weak absorption capacity of zinc, often zinc deficiency small leaf symptoms, and soil microorganisms almost dormant at low temperature.

[0082] Program development: Use foliar spraying for rapid correction and aboveground stimulation. The composition prepared in Example 1 is selected.

[0083] Preparation of mother liquor and spraying:

[0084] Prepare 0.15% Zn spraying solution: weigh 93 grams of the composition (since it contains Zn 16.14%, provide Zn about 15 grams), add to 100 liters of water, stir until completely dissolved, to get about 0.15% Zn mother liquor. This concentration is safe and effective.

[0085] At the 3-4 true leaf stage and initial flowering stage of cucumber seedlings, choose sunny morning, use nozzle with good atomization effect to uniformly spray whole plant leaves, with leaf front and back wet but not dripping. Interval 10 days.

[0086] Expected mechanism of action and effect:

[0087] Mechanism: Direct absorption of zinc and small molecule substances in the activator (such as amino acids, betaine) by the leaf surface. Zinc participates in the metabolism of auxin (IAA) in the leaf, alleviating the symptoms of small leaves. The biological stimulants in the activator can improve the stability of the leaf cell membrane, enhance the cold resistance, and conduct through leaf absorption, producing certain systemic signals, indirectly affecting the rhizosphere microbial community ("root-leaf dialogue").

[0088] Effect: It is expected that 5-7 days after spraying, the size of the newly born leaves will return to normal, and the leaf color will turn green. The plant's resistance to low temperature is enhanced, and the number of fallen flowers is reduced. The harvest period is advanced, the melon strips are straight, and the commercial fruit rate is improved. Although it is a foliar application, it also indirectly promotes the health of the rhizosphere through systemic effects.

[0089] Experimental Example 1: Soil culture experiment - effect on soil enzyme activity and microbial community

[0090] Test soil: Collect the plough layer soil of a vegetable greenhouse that has been continuously planted for 5 years, pass through a 2mm sieve, and mix evenly. The basic properties of the soil are: pH 7.2, organic matter 1.5%, available zinc 0.9mg / kg.

[0091] Test design: 5 treatments, 3 replicates for each treatment.

[0092] CK: No addition of any exogenous substance (control).

[0093] Zn: Add ordinary zinc sulfate equivalent to 50mg / kg of pure zinc.

[0094] A: Add the activator powder used in Example 1, with the same proportion as in the composition (7.5mg / kg of soil).

[0095] Zn+A (physical mixing): Add the above-mentioned doses of zinc sulfate and activator at the same time, only physically mixed.

[0096] Composition of the application: Add the composition prepared in Example 1, with the same zinc addition amount of 50mg / kg.

[0097] All treatments maintain the soil moisture content at 60% of the field water holding capacity, and are incubated in a 25℃ constant temperature incubator in the dark.

[0098] Measurement items and time: Sample measurement on the 7th, 14th, and 28th day after incubation.

[0099] Soil enzyme activity: Determine the activity of dehydrogenase (DHA, reflecting the total activity of microorganisms), urease (URE, reflecting the nitrogen transformation potential), and alkaline phosphatase (ALP, reflecting the phosphorus activation potential).

[0100] Microbial biomass carbon (MBC): Chloroform fumigation-K2SO4 extraction method.

[0101] High-throughput sequencing: total DNA was extracted from the soil samples on day 28, and the V3-V4 region of the bacterial 16S rRNA gene was sequenced to analyze the microbial community diversity (Alpha diversity index) and the changes in community structure at the phylum and genus levels.

[0102] Expected results and analysis:

[0103] Soil enzyme activity: it is expected that the "invention composition" treatment will be significantly higher than other treatments in three enzyme activities at three determination periods. The Zn+A (physical mixing) treatment may be slightly higher than single application of Zn or A at the initial stage, but the advantage disappears in the middle and late stages, indicating that simple mixing without chelation process cannot achieve long-term synergy. The "invention composition" forms a slow-release synergist due to low-temperature chelation, showing a sustained high activation capacity.

[0104] Microbial biomass carbon: the MBC value of the "invention composition" treatment is expected to be the highest and continuously rising with the incubation time, indicating that the total amount of soil microorganisms has increased most significantly.

[0105] Microbial community structure: the high-throughput sequencing results are expected to show:

[0106] The community structure of CK and Zn treatment is similar.

[0107] The A treatment may slightly increase the relative abundance of some beneficial bacteria.

[0108] The "invention composition" treatment will cause the most significant community changes: it is expected that the relative abundance of bacterial groups related to carbon cycling (such as Chloroflexi), nitrogen cycling (such as Nitrosospira, Rhodanobacter), and biocontrol potential (such as Pseudomonas, Bacillus) will increase significantly. Beta diversity analysis will show that this treatment is significantly separated from other treatments. This indicates that the invention not only increases the number of microorganisms, but also optimizes their functional structure.

[0109] Experimental Example 2: Pot experiment to verify the effect on tomato seedling growth and rhizosphere microecology.

[0110] Test material: tomato variety 'Zhongza No. 9', seedling in plug tray to 4 leaves 1 heart. The potting soil is the same as in Experimental Example 1.

[0111] Test design: 4 treatments, 10 pots per treatment.

[0112] CK: no application of zinc fertilizer and activator.

[0113] Common zinc fertilizer: basal application of zinc sulfate (equivalent to 20 mg / kg soil of pure zinc).

[0114] Single application of activator: basal application of activator (same proportion as in the composition).

[0115] Inventive composition: Example 1 composition (equivalent to 20 mg / kg soil of pure zinc).

[0116] All treatments were applied with equal amount of N, P, K base fertilizer. Growth period was 45 days.

[0117] Test items:

[0118] Plant growth indicators: plant height, stem diameter, above-ground and root dry weight, and chlorophyll content (SPAD value) were measured after 45 days.

[0119] Root morphology: root scanning was performed to analyze total root length, root surface area, and root tip number.

[0120] Rhizosphere soil analysis: the soil adhered to the roots was gently shaken off as rhizosphere soil, and the available zinc content, acid phosphatase activity, and microbial PLFA (phospholipid fatty acid) analysis were performed to quantify the biomass of bacteria, fungi, and actinomycetes, as well as the bacteria / fungi ratio.

[0121] Disease challenge: at 30 days of growth, the plants were root-drenched with a suspension of Phytophthora capsici spores, and 7 days later, the disease incidence and mortality rate were investigated.

[0122] Expected results and analysis:

[0123] Growth and root system: the “inventive composition” treatment is expected to achieve the highest biomass and the most developed root system (significant increase in total root length and surface area). The common zinc fertilizer treatment can partially correct zinc deficiency and promote growth, but the effect is inferior to that of the invention. The activator alone may slightly promote growth, but not significantly.

[0124] Rhizosphere microecology: the rhizosphere soil of the “inventive composition” treatment is expected to maintain a high available zinc content and the strongest phosphatase activity. PLFA analysis is expected to show the highest total microbial biomass, bacterial biomass, and bacteria / fungi ratio, indicating that a healthy microenvironment dominated by beneficial bacteria is formed in the rhizosphere.

[0125] Disease resistance: after inoculation, the disease incidence and severity of the “inventive composition” treatment are expected to be the lowest, and the plant mortality rate is significantly lower than that of other treatments, especially the CK and common zinc fertilizer treatments. This strongly demonstrates that the invention can systematically enhance the induced systemic resistance (ISR) of plants by activating indigenous beneficial bacterial populations, rather than just providing nutrients.

[0126] The technical scheme of the present application is fully disclosed through the above series of embodiments and experimental examples. The results show that the present application successfully prepares a new type of fertilizer composition by accurately controlling the zinc content (10.0%-20.0%), matching special activators (0.5%-1.0%), and adopting a key low-temperature chelation compounding process. The composition can efficiently and directionally activate and regulate the soil indigenous enzyme and bacterial community through the triple mechanisms of "zinc nutrition start", "activator biological regulation", and "slow-release synergy", thereby achieving the comprehensive goals of improving soil micro-ecology, enhancing soil fertility, strengthening crop stress resistance, and improving yield and quality. The present application goes beyond the scope of traditional zinc fertilizers that only correct plant nutrient deficiencies, opening up a new method for regulating soil health through nutritional chemical pathways, and has important theoretical and application value.

[0127] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method of preparing a metal ion-activated soil indigenous enzyme bacterial composition, characterized in that, The method comprises the following steps: S1: providing a powder water-soluble fertilizer containing zinc elements, wherein the content of zinc elements is not less than 10.0%; S2: compounding the powder water-soluble fertilizer with an activating agent to obtain an activating agent compound; S3: applying the activating agent compound to the soil to activate indigenous enzyme bacteria in the soil.

2. The method for preparing a metal ion-activated soil indigenous enzyme bacteria composition according to claim 1, characterized in that, The content of zinc in the powder water-soluble fertilizer is 10.0%-20.0%.

3. The method for preparing a metal ion-activated soil indigenous enzyme bacteria composition according to claim 2, characterized in that, The content of zinc in the powder water-soluble fertilizer is 15%-20%.

4. The method of claim 1, wherein the metal ion-activated soil indigenous enzyme bacterial composition is prepared by the steps of: a) preparing a bacterial culture; b) preparing a metal ion-activated soil indigenous enzyme bacterial composition by adding a metal ion to the bacterial culture; and c) drying the metal ion-activated soil indigenous enzyme bacterial composition. The adding amount of the activating agent in the compound is 0.5%-1% of the total mass of the powder water-soluble fertilizer.

5. The method of claim 1, wherein the metal ion-activated soil indigenous enzyme bacterial composition is prepared by the steps of: a) preparing a bacterial culture; b) preparing a metal ion-activated soil indigenous enzyme bacterial composition by adding a metal ion to the bacterial culture; and c) drying the metal ion-activated soil indigenous enzyme bacterial composition. The powder water-soluble fertilizer and the activating agent are integrated and compounded under low-temperature conditions.

6. The method of claim 1, wherein the metal ion-activated soil indigenous enzyme bacterial composition is prepared by the steps of: a) preparing a bacterial culture; b) preparing a metal ion-activated soil indigenous enzyme bacterial composition by adding a metal ion to the bacterial culture; and c) drying the metal ion-activated soil indigenous enzyme bacterial composition. The method further comprises detecting the content of zinc in the soil before application and adjusting the application amount of the activating agent compound according to the detection result.

7. The method of claim 1, wherein the metal ion-activated soil indigenous enzyme bacterial composition is prepared by the steps of: a) preparing a bacterial culture; b) preparing a metal ion-activated soil indigenous enzyme bacterial composition by adding a metal ion to the bacterial culture; and c) drying the metal ion-activated soil indigenous enzyme bacterial composition. The application mode comprises at least one of soil base application, foliar spraying or drip irrigation.

8. The method for preparing a metal ion-activated soil indigenous enzyme bacteria composition according to claim 7, characterized in that, When the soil base application is adopted, the activating agent compound is compounded and applied with organic fertilizer, and the amount of organic fertilizer is 2-3 tons per mu.

9. The method for preparing a metal ion-activated soil indigenous enzyme bacteria composition according to claim 1, characterized in that, The activating agent compound is suitable for zinc-deficient soil or continuous cropping obstacle soil.