Composite microbial fertilizer synergist capable of cooperating with multiple beneficial strains and production method of composite microbial fertilizer synergist

Abstract

The invention relates to the technical field of composite microbial fertilizer manufacturing, and discloses a composite microbial fertilizer synergist capable of cooperating with multiple beneficial strains and a production method thereof, and the production method comprises the following steps: mixing a hydrophilic temporary storage agent with a basic carrier, spraying critical water lower than a microbial activation threshold value, and uniformly stirring; inducing the surface gelling of the hydrophilic temporary storage agent by using water to form a viscous micronucleus; the preparation method comprises the following steps: firstly, adding a hydrophobic separant and a core flora, realizing spontaneous selective coating by utilizing a micronucleus viscous surface, and finally dispersing a pioneer flora into a matrix outside a coating structure. A microcosmic functional structure of particles is preset in a preparation process, so that the activation relationship of microorganisms after meeting water is competed by disordered synchronous resources, and the microcosmic functional structure of the particles is changed into the microcosmic functional structure of the particles, and the microcosmic functional structure of the particles is changed into the microcosmic functional structure of the particles; the method is converted into deterministic time sequence ecological niche relay, so that the advantage of diversity of strains in the formula can be exerted in practical application.

Description

TECHNICAL FIELD

[0001] The present application relates to a synergistic multi-strain microbial fertilizer synergist and its production method, belonging to the technical field of compound microbial fertilizer manufacturing. BACKGROUND

[0002] Currently, with the increasing demand for the diversity and functional synergy of bacterial strains in fertilizers, the above-mentioned manufacturing method pursuing physical homogenization has begun to restrict its application effect due to its inherent limitations. Specifically, when the fertilizer granules encounter non-uniform trace moisture during storage or at the initial stage of field application, the homogenized internal structure will cause all strains to be awakened simultaneously. In the microenvironment of the granules, different bacterial groups compete for limited moisture and available nutrients, leading to a decrease in the activity of some slow-starting or environment-sensitive functional strains, making it difficult to effectively maintain the designed bacterial diversity advantage in the formula.

[0003] Analysis shows that the root cause of this problem is not the biological characteristics of specific strains, but the moisture response mechanism determined by the homogenized structure of the fertilizer granules. This manufacturing concept of pursuing physical homogenization not only fixes the structure of the granules, but also fundamentally limits the ability to control the activation timing of multi-strain systems, leading to a lack of control strategies in existing technologies. For example, Chinese Patent No. CN101928186B discloses a compound microbial fertilizer for preventing and treating crop diseases and pests and its preparation method. Although this patent combines Bacillus megaterium, Bacillus mycoides with yield-increasing function and Bacillus thuringiensis, Bacillus subtilis with disease and pest control function, in its preparation method, all functional bacterial agents, organic matter, inorganic fertilizers, and other components are blended in one step, and finally the fertilizer is made through mixing, granulation, and drying. The essence of this process is to pursue the uniform distribution of each component in statistics, which inevitably leads to the mixing of all functional strains together in a physically homogenized granule. Once water is encountered, different functional bacterial groups are activated simultaneously, which directly triggers the aforementioned resource competitive internal consumption problem, making it impossible to achieve non-competitive and time-sequential activation between bacterial groups, thereby limiting the final efficiency of the conversion of bacterial diversity to functional diversity in formula design. The existing improvement ideas of optimizing strain screening or adjusting carrier nutrition do not change the physical premise of internal homogenization of the granules, so the situation of synchronous activation of all strains and subsequent resource competition cannot be avoided.

[0004] Specifically, the prior art mainly exists in the following aspects: 1. The homogeneous particle structure makes it difficult to achieve non-competitive and time-sequential activation of microorganisms in principle; 2. The stability of the microbial community is greatly affected by the external moisture environment before the product is applied, and lacks an internal regulation mechanism; 3. The conversion efficiency of the functional diversity of the formula design strain diversity is limited in actual application. Therefore, how to pre-construct the internal microstructure of the particles in the conventional fertilizer manufacturing process to regulate the activation sequence of the multi-strain system after encountering water, and convert the synchronous competition of resources into an orderly relay utilization relationship, has become a technical problem to be solved by the present application. SUMMARY

[0005] The present application provides a kind of synergistic multi-strain complex microbial fertilizer synergist and its production method, its main purpose is to solve the problem that the synchronous activation of microorganism is caused by the homogeneous manufacturing method, and the diversity of strain cannot guarantee the effective application of the advantages.

[0006] To achieve the above-mentioned purpose, the present application provides a kind of synergistic multi-strain complex microbial fertilizer synergist, the synergist is a granular composition comprising multiple functional partitions, the granular composition is prepared by the method comprising the following steps: Step a, mix the organic matter powder as the base fertilizer carrier, a dry superabsorbent polymer as a hydrophilic temporary agent, and a lignosulfonate as a flexible skeleton agent in a mixing device; then spray liquid water into the continuously stirred mixed powder, and the amount of liquid water sprayed is set within a critical range, the lower limit of the critical range is defined by the technical condition that the dry superabsorbent polymer particle surface is swollen and gelled to form multiple discrete gel nuclei with surface adhesion, and the upper limit of the critical range is defined by the technical condition that the water activity of the entire powder system is lower than the biological activation threshold of the preset multiple beneficial strains; Step b, add a micro-hydrophobic isolation agent and at least one dormant bacteria agent of the first type of beneficial strain to the device, and under the gradient driving of the physical and chemical forces between the hydrophobic isolation agent and the surface of the discrete gel nuclei, the hydrophobic isolation agent and the first type of bacteria agent spontaneously and selectively adhere to the surface of the discrete gel nuclei, thereby constructing multiple core-shell structure precursors with discrete gel nuclei as the core and the hydrophobic isolation agent and the first type of bacteria agent as the shell on the microscale; Step c, add at least one dormant bacteria agent of the second type of beneficial strain to the device and mix, so that the second type of bacteria agent is dispersed in the external space of the core-shell structure precursor composed of the base fertilizer carrier.

[0007] Preferably, the amount of liquid water sprayed in step a is subjected to a rule directly related to the physical properties of superabsorbent polymers and the biological characteristics of beneficial bacterial strains, which is defined by the following inequality: wherein, is the dry weight of superabsorbent polymers; is the minimum water absorption coefficient required for reaching surface swelling gelation, which is preset according to the material specifications of superabsorbent polymers; is the total dry weight of the mixed powders; is the biological activation water activity threshold value, which is preset according to the strain characteristics of various beneficial bacterial strains; is the molar mass of water.

[0008] Preferably, the hydrophilic temporary storage agent is sodium polyacrylate, potassium polyacrylate or calcium polyacrylate; the micro-hydrophobic isolation agent is diatomite surface-modified by silane or fatty acid; the base fertilizer carrier is humic acid powder or grass charcoal powder; the flexible skeleton agent is lignin sulfonate, which, in the dry state of the composition, interweaves with the base fertilizer carrier and other components through its macromolecular chains to form a flexible polymer network for absorbing and dispersing mechanical stress to inhibit the generation of micro-fissures; and when the composition encounters moisture intrusion, the lignin sulfonate on the micro-fissure wall absorbs water to swell and form a high-viscosity gel to block the rapid penetration path of moisture along the micro-fissure.

[0009] Preferably, the hydrophilic temporary storage agent is selected to be calcium polyacrylate or potassium polyacrylate; when the moisture carrying heavy metal ions in the form of multivalent cations enters the composition and is absorbed by the hydrophilic temporary storage agent, the hydrophilic temporary storage agent captures and fixes the heavy metal ions through ion exchange while releasing calcium ions or potassium ions into the hydrogel micro-environment formed by the hydrophilic temporary storage agent.

[0010] Preferably, the composition further comprises a metabolic response microcapsule; the metabolic response microcapsule encapsulates a functional enhancer in its core and is composed of a material that is sensitive to the micro-zone chemical environment changes caused by the metabolic products of the first type of beneficial bacterial strains or the second type of beneficial bacterial strains after they are activated by moisture and enter an active metabolic state.

[0011] Preferably, the micro-zone chemical environment changes are a decrease in pH value; the shell of the metabolic response microcapsule is a composite material of chitosan and sodium alginate, which is stable in neutral or weakly alkaline environments and disintegrates in acidic environments with a pH value below 6.0; the functional enhancer is a molybdate, a cobalt salt, a quorum-sensing inducer or a preset amino acid precursor.

[0012] Preferably, the composition further comprises a temperature-gated activation microcapsule; the temperature-gated activation microcapsule encapsulates a solid organic acid in its core and is composed of a phase-change material with a preset melting point, which is set within the range of 10 degrees Celsius to 20 degrees Celsius.

[0013] Preferably, the solid organic acid is citric acid powder; the phase change material is stearic acid or palmitic acid; when the ambient temperature reaches the preset melting point, the shell melts and releases the solid organic acid, which acts as an exogenous chemical signal to trigger the metabolic response of the microcapsule shell to disintegrate.

[0014] Preferably, the granular composition has a physical inhomogeneous structure at the microscale, which includes: a core composed of superabsorbent polymer; a shell layer composed of micro-hydrophobic isolating agent mixed with the first type of beneficial bacterial strain coated on the surface of the core; and a matrix composed of basic fertilizer carrier, lignosulfonate mixed with the second type of beneficial bacterial strain filled in the external space of the core-shell structure precursor.

[0015] A production method of a synergistic multi-beneficial bacterial strain composite microbial fertilizer synergist, comprising the following steps: Step a, mixing organic matter powder as a basic fertilizer carrier, dry superabsorbent polymer as a hydrophilic temporary storage agent, and lignosulfonate as a flexible skeleton agent in a mixing device; then spraying liquid water in the critical range into the continuously stirred mixed powder to induce the surface of the superabsorbent polymer to swell and gel, thereby forming a plurality of discrete gel nuclei with surface adhesion, while ensuring that the water activity of the entire powder system is below the biological activation threshold of the beneficial bacterial strain; Step b, adding a micro-hydrophobic isolating agent and at least one dormant bacterial agent of the first type of beneficial bacterial strain to the mixing device, using the surface adhesion of the discrete gel nuclei to drive the hydrophobic isolating agent and the first type of bacterial agent to spontaneously and selectively adhere and coat the surface of the discrete gel nuclei, thereby constructing a plurality of core-shell structure precursors with the discrete gel nuclei as the core and the hydrophobic isolating agent and the first type of bacterial agent as the shell at the microscale; Step c, adding at least one dormant bacterial agent of the second type of beneficial bacterial strain to the mixing device and mixing to disperse the second type of bacterial agent in the external space of the core-shell structure precursor composed of the basic fertilizer carrier, and finally obtaining the granular composition.

[0016] Compared with the prior art, the beneficial effects of the present application are: 1. By introducing micro-hydrophobic isolators with specific physico-chemical properties and hydrophilic temporary storage agents into the base fertilizer carrier, the mixture is not formed into statistically uniform particles during the conventional extrusion or rolling granulation process, but rather a physically heterogeneous functional zoned structure is spontaneously constructed on the microscale within the particles, with different components responding differently to water and mechanical forces. This pre-set internal structure in the manufacturing process is the physical basis for the subsequent recovery of microbial populations in a predetermined order, which changes the manufacturing process of fertilizer particles from a process of pursuing macroscopic homogenization of material mixing to a process of structurally constructing microscale functional zones within the particles.

[0017] 2. Based on the physical zoning formed within the particles, when external water invades, its penetration path and distribution rate are governed by the structure, and water is no longer a homogeneous signal that triggers the recovery of all microorganisms at the same time, but is transformed into a heterogeneous activation sequence with a time difference. Water preferentially wets the unshielded base carrier area to activate the pioneer microbial population, then slowly penetrates the hydrophobic isolation area, and finally provides water from the local high-humidity area formed by the hydrophilic temporary storage agent. This water conduction mode determined by the particle physical structure changes the relationship between microbial populations from direct competition for limited resources in the same time and space to a niche relay that is activated in different time windows and different microenvironments.

[0018] 3. By introducing metabolic response microcapsules, a material release link controlled by the life activities of microorganisms is further constructed based on the above time-sequential activation driven by water. After being awakened by water and entering an active metabolic state, specific functional microbial populations change the chemical environment of their microzones with metabolic products such as organic acids. This change in the environment becomes a signal to unlock the microcapsules, which in turn release functional enhancers needed to trigger their specific biological functions. This secondary response mechanism from water signals to metabolic signals directly links the release of functional substances to the real physiological state of microorganisms, avoiding resource mismatch caused by the release of functional substances at the early stage of strain recovery. By further introducing temperature-gated activation microcapsules, a pre-activation condition determined by the external physical environment is set for the above biochemical response process. Only when the environmental temperature reaches the preset value, such as the temperature at which crops begin to actively grow, will the phase change material shell of the microcapsule melt, releasing chemical signal substances that can directly trigger metabolic response microcapsules, so that the entire functional activation chain remains in a standby locked state even if water is present under conditions that are not suitable for the efficient work of functional microbial populations. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 Process flow chart for the preparation of the heterogeneous functional particles of the present invention; Fig. 2 This is a diagram illustrating the environmental response and functional release mechanism of the present invention. Fig. 3 This is a dynamic comparison diagram of the water saturation process of the particles of this invention and conventional homogeneous particles. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] A compound microbial fertilizer synergist incorporating multiple beneficial microbial strains and its production method are disclosed. The overall process is configured within a conventional mixing and granulation device, employing a three-step sequential feeding procedure consisting of core shaping and toughening, shell construction, and matrix filling to construct a heterogeneous internal structure within the fertilizer granules. This production method can further integrate functional modules such as flexible framework reinforcement, specific ion purification, release of metabolic response substances, and temperature-gated activation. The synergist ultimately presents as a granular composition whose internal structure determines its ability to transform the activation process of different microorganisms from synchronous competition to a sequential relay when interacting with external moisture. In the manufacture of compound microbial fertilizers, the uniform distribution of components produced by conventional dry blending and granulation processes leads to the formation of all microorganisms at the microscopic level. Dormant bacterial strains are indiscriminately and synchronously activated upon encountering moisture, leading to competition for limited resources within fertilizer granules and reducing the ultimate survival rate of functional strains. To address this issue, the method disclosed in this application employs a critical hydration self-assembly coating process. During manufacturing, moisture, which serves as a medium for bioactivation signals in the final application, is controllably used as a shaping tool to guide the formation of physical structures. This induces different functional material components to complete an orderly physical coating process at the particle scale without activating dormant strains. Ultimately, a physically heterogeneous functional partition structure consisting of a core, shell, and matrix is ​​constructed within the fertilizer granules. This structure provides the physical prerequisite for the subsequent temporal activation of the bacterial community.

[0022] The initial state of the production method is defined as follows: all materials to be compounded, including the basic fertilizer carrier, hydrophilic temporary storage agent, hydrophobic isolation agent, flexible skeleton agent, and at least two dormant bacterial agents, are dry powdery solids that meet agricultural production standards; wherein, the basic fertilizer carrier is preferably humic acid powder or peat powder with a particle size distribution between 80-120 mesh; the hydrophilic temporary storage agent, which serves as the viscous micronucleus in the subsequent self-assembly process and the water storage unit in the final application, is preferably dry sodium polyacrylate, potassium polyacrylate, or calcium polyacrylate micropowder, with an initial water absorption ratio of not less than 200 times its own weight; the hydrophobic isolation agent, which serves to construct moisture... The slow-moving layer for penetration is preferably diatomaceous earth surface-modified with silane or fatty acids, with a static water contact angle greater than 90 degrees; the flexible skeleton agent, which enhances the mechanical toughness of the particles and provides a sealing function for microcracks, is preferably lignin sulfonate powder; both the first and second types of beneficial strains are dormant bacterial agents, with initial water activities below 0.5; the entire production method is carried out in a horizontal ribbon mixer, which has a mixing system with an adjustable speed within the range of 30-60 rpm, and an atomizing nozzle system capable of uniformly spraying liquid water in the form of 5-10 micron droplets, with the ambient temperature controlled at 25 degrees Celsius. The relative humidity is below 40%.

[0023] The first step in the production method is the shaping and toughening of the core. The procedure begins by adding 60-80% of the total dry weight of the base fertilizer carrier, along with all the hydrophilic temporary storage agent and all the flexible skeleton agent, into a mixer. This is followed by dry premixing at 30-50 rpm for 2-3 minutes to form a homogeneous dry powder mixture. Then, liquid deionized water is sprayed into the continuously stirred powder mixture through an atomizing nozzle. The amount of liquid water injected is... It is bound by a rule relating to the physical properties of superabsorbent polymers and the biological characteristics of beneficial strains, which is defined by the following inequality: ;in, The amount of liquid water injected is expressed in kilograms. The dry weight of the superabsorbent polymer is expressed in kilograms. The minimum water absorption ratio coefficient required for the superabsorbent polymer to achieve surface swelling and gelation is a dimensionless parameter. The total dry weight of the mixed powder is expressed in kilograms. The biological activation water activity threshold is a dimensionless parameter preset based on the characteristics of various beneficial strains. The molar mass of water is approximately 18.015 g / mol. The value was determined through an experimental calibration procedure: 100 grams of the superabsorbent polymer to be tested were placed in a stirrer, and pure water was added dropwise at a rate of 1 ml / min. The stirring resistance was monitored using a torque sensor. When the resistance first showed a non-linear, sharp increase at an inflection point, the amount of water added at this point was recorded. The ratio of this water amount to 100 grams is the value. ; Based on the technical specifications provided by the strain supplier or determined through standard microbiological experiments, the value is typically between 0.6 and 0.7; for example, in a batch, It weighs 10 kilograms. It weighs 300 kg and has been calibrated. The value was 0.25, the most sensitive strain used. If it is 0.65, then The range of values ​​for is determined to be greater than or equal to kilograms, and less than kilograms, therefore under these conditions The operable window is between 2.5 kg and 3.55 kg; under this critical water volume, the surface of the hydrophilic temporary storage agent particles swells and transforms into a discrete gel core with high surface adhesion, while the water activity of the entire powder system is still controlled below the strain activation threshold. At the same time, the macromolecular chains of lignin sulfonate begin to intertwine with the basic carrier, pre-constructing the structural toughness of the subsequent particles.

[0024] The second step, shell construction, is then performed. The procedure is as follows: immediately after completing the previous step, all the microscopic hydrophobic isolating agent and at least one dormant bacterial agent of the first type of beneficial strain serving as the core functional bacterial group are added to a mixer and stirred continuously. Because a physical force determined by the surface energy gradient exists between the hydrophobic powder and the hydrophilic viscous surface of the hydrogel core formed in step one, this force drives the subsequently added hydrophobic isolating agent and the first type of bacterial agent to spontaneously and selectively adhere to and coat the surface of the discrete gel core. This constructs multiple core-shell structure precursors at the particle scale, with the discrete gel core as the core and the hydrophobic isolating agent and the first type of bacterial agent as the shell. This process is continued with stirring for 1-2 minutes until, upon sampling and observation, the powder color is uniform, indicating that the coating process is essentially complete. To stably obtain the aforementioned core-shell structure precursors, the particle size of the powder serving as the hydrophobic isolating agent and the particle size of the first type of bacterial agent are... There is a specific geometric constraint relationship between the particle sizes of the hydrophilic temporary storage agent. Specifically, the D50 particle size of the hydrophobic isolation agent powder is controlled to be no greater than 1 / 10 of the D50 particle size of the hydrophilic temporary storage agent. Meanwhile, the surface adhesion work of the discrete gel core formed after the critical water injection is calibrated by a probe-type viscosity tester. The calibration process records the maximum pull required when the probe contacts and separates from the gel core surface. This pull value is controlled within an operating window of 0.5-2.0 mN. A pull value below the lower limit of this window indicates insufficient gelation and inability to effectively capture the hydrophobic powder, while a pull value above the upper limit of this window indicates that the water activity may exceed the bacterial activation threshold. Those skilled in the art can confirm the conventional process conditions for a specific batch of material by adjusting the injection amount of critical water and the initial particle size distribution of the hydrophilic temporary storage agent, and by monitoring the above process parameters.

[0025] Finally, the third step, matrix filling, is performed. The procedure involves adding at least one dormant bacterial agent of a second type of beneficial strain, representing the pioneer dominant bacterial group, into the equipment and performing a short final mixing for 30-60 seconds. This allows the second type of bacterial agent to be evenly dispersed in the external space of the core-shell structure precursor, which is composed of the basic fertilizer carrier, forming the final matrix area. After this three-step process, the material's internal functional zones are pre-defined. Subsequently, this mixture is transferred to an extrusion granulator for granulation through a template with a pore size of 2-4 mm. Finally, the granulation process is carried out at a temperature below 40°C. The product is dried at low temperature under certain conditions until the moisture content of the final product is less than 5%, thereby removing the critical moisture introduced during the manufacturing process as a molding tool, and obtaining the final granular composition product. This product has a physically heterogeneous structure at the particle scale, which specifically includes: a core composed of a highly absorbent polymer; a shell covering the surface of the core composed of a micro-hydrophobic isolating agent and a first type of beneficial strain; and a matrix filling the outer space of the core-shell structure precursor, composed of a basic fertilizer carrier, lignin sulfonate and a second type of beneficial strain.

[0026] In the production process integrating the metabolically responsive microcapsules and temperature-gated start-up microcapsules, to maintain their structural integrity during the subsequent extrusion granulation process, the mechanical property parameters of the microcapsules themselves and the operating parameters of the extrusion granulator are configured into a synergistic constraint relationship. Specifically, the average bursting load value of this batch of microcapsules is first obtained through nanoindentation testing using atomic force microscopy. Subsequently, during the extrusion granulation step, the maximum shear and extrusion stress exerted by the granulator screw on the material system is controlled to achieve the equivalent pressure on the material particles by adjusting the screw speed and die opening ratio. Always lower than The established safety threshold, this procedure directly converts the material mechanical properties of microcapsules into an executable, quantifiable process control parameter for the granulation equipment, thereby avoiding premature breakage of microcapsules due to mechanical stress; in an alternative embodiment, to address the problem of cracks in fertilizer granules caused by mechanical stress during transportation and application, which in turn disrupts the preset moisture conduction path, the production method adds a flexible skeleton agent, lignin sulfonate, in the shaping and toughening stage of step a. In the dry state of the composition, lignin sulfonate, through its macromolecular chains, interweaves with the basic fertilizer carrier and other components to form a flexible polymer network, which absorbs and disperses mechanical stress to suppress crack formation; and when When external moisture intrudes along accidentally formed fissures, the lignin sulfonate on the fissure walls preferentially absorbs water and swells, forming a high-viscosity gel. This gel physically blocks the rapid infiltration channels of water along the fissures, forcing water back to the slow infiltration path set by the hydrophobic isolation layer, thus ensuring the integrity of the sequential activation function. In another alternative embodiment, to address the problem that the hydrophilic temporary storage agent may accumulate harmful ions and form a local high-concentration inhibition zone when the fertilizer is applied in heavy metal-contaminated or high-salt soils, the hydrophilic temporary storage agent used in the production method is specifically selected as calcium polyacrylate or potassium polyacrylate. When carrying heavy metal ions in the form of polyvalent cationic forms (such as... When water enters the composition and is absorbed by the hydrophilic temporary storage agent, based on the principle of ion exchange selectivity, the carboxyl groups on the polymer backbone preferentially capture and fix heavy metal ions, while releasing calcium or potassium ions into the hydrogel microenvironment formed by it. This process actively purifies the local environment on which the core bacteria depend for survival before activating the core bacteria, and transforms the potential inhibitory effect into nutrient supply.

[0027] To address the resource allocation challenges of functional strains requiring specific micronutrients to efficiently perform their biological functions after resuscitation, the granular composition may further include a metabolically responsive microcapsule. The core of this microcapsule encapsulates a functional enhancer, such as molybdate for nitrogen-fixing bacteria or quorum sensing inducer for resistant bacteria. Its outer shell is made of a material sensitive to pH changes caused by microbial metabolic activity, preferably a composite of chitosan and sodium alginate. This shell remains structurally stable in neutral or weakly alkaline environments but disintegrates in acidic environments with a pH below 6.0. These metabolically responsive microcapsules are added along with the second type of bacterial agent during the matrix filling step of the production process. Upon application of the granules, the moisture-awakened strains enter an active metabolic cycle. In the metabolic state, the microorganisms' metabolic products, such as organic acids, cause a decrease in the pH of their surrounding area. Once the pH falls below a preset disintegration threshold of 6.0, the microcapsule shell dissolves, precisely releasing the core material at the time and place when the microbial community needs the functional enhancer. This constructs a two-stage response mechanism initiated by water signals and followed by metabolic signals. Furthermore, to address the issue of delayed activation of the above biochemical response mechanism under low-temperature conditions such as spring sowing due to slow microbial metabolism, the composition may also include a temperature-gated initiation microcapsule. The core of this temperature-gated initiation microcapsule encapsulates a solid organic acid, such as citric acid powder, and its shell is made of a phase change material with a preset melting point. This preset melting point is set at the minimum effective soil temperature meaningful for the growth of the target crop, for example, 10°C. Up to 20 Within the specified range, stearic acid or palmitic acid can be selected as the specific material. The temperature-gated microcapsule is also added during the matrix filling step. When the ambient temperature is lower than the melting point of its shell, the citric acid in the core is locked even if moisture is present, and the entire functional activation chain remains on standby. When the soil temperature warms up and reaches the preset melting point, the shell of the phase change material undergoes physical melting, releasing the citric acid in the core. This citric acid acts as an exogenous chemical signal, lowering the local pH value to a level sufficient to trigger the disintegration of the metabolic response microcapsule, thereby activating the entire functional activation chain.

[0028] To ensure the reproducibility of the technical solution disclosed in this invention and to illustrate the decisive role of the ratio range of its core components in the final technical effect, the following supplementary explanation is provided: In one specific embodiment, the dry weight percentage range of each component of the granular composition is set as follows: basic fertilizer carrier 65%-85%, hydrophilic temporary storage agent 2%-10%, microscopic hydrophobic isolation agent 4%-15%, flexible skeleton agent 0.5%-5%, and dormant bacterial agents of the first and second types of beneficial strains totaling 0.2%-4%; wherein, a preferred ratio range is: basic fertilizer carrier 70%-80%, hydrophilic temporary storage agent 3%-7%, microscopic hydrophobic isolation agent 6%-12%, flexible skeleton agent 1%-3%, and dormant bacterial agents of the two types totaling 0.5%-2%. The engineering basis for limiting the ratio range of the key components is that the content of the hydrophilic temporary storage agent directly determines the surface adhesion work of the discrete gel core formed after critical hydration. When its content is below 2%, the number of gel cores formed is insufficient or the surface adhesion is too low, making it unable to effectively capture and coat the subsequently added hydrophobic isolating agent powder. This results in a physical discontinuity in the shell structure, allowing water to rapidly penetrate along this discontinuous path, thus rendering the sequential activation function ineffective. When its content is above 10%, on the one hand, the process window requirements for the critical water injection rate during production become more stringent, increasing the risk that the system's water activity will exceed the strain activation threshold. On the other hand, when the granules are exposed to water after application, excessive swelling may damage the physical integrity of the granules. The content of the micro-hydrophobic isolating agent directly determines the thickness and density of the shell. This allows for the control of the time required for water to penetrate the layer. When the content is below 4%, the resulting shell is too thin or porous, failing to effectively delay water penetration. This causes the activation time windows of the first and second types of strains to overlap, leading to resource competition. When the content is above 15%, the shell's barrier effect on water is too strong, potentially preventing water from reaching and activating the first type of beneficial strains within the core during the time window required for crop growth. This causes them to miss the opportunity to grow synergistically with the crop, thus failing to achieve the intended technical objective. Therefore, controlling the proportions of each group within a specified range is a prerequisite for constructing an effective physical heterogeneous structure and achieving sequential relay of the microbial community.

[0029] Example 1: In a spring-sown corn application in northern China, the soil surface moisture distribution is uneven due to the diurnal temperature range, with some areas being moist while others are dry, and the soil temperature is below 15°C. This operating condition inhibits the effective survival and colonization of microbial strains in conventional compound microbial fertilizers. When the granular composition prepared using the method disclosed in the aforementioned specific embodiments is applied to this type of soil, its internal physical heterogeneous structure interacts with environmental moisture. Initially, limited moisture in the moist areas of the soil comes into contact with the composition particles, wetting the matrix area of ​​the particles, thereby selectively activating a second type of beneficial strain dispersed in that area, such as Bacillus subtilis. The revival of this microbial community does not trigger a response from other microbial species within the particles, but rather begins preliminary colonization in the soil area surrounding the particles, and its metabolic activity begins to alter the physicochemical properties of the rhizosphere. With subsequent irrigation or rainfall, water enters the soil and infiltrates... As the water penetrates the particles, its conduction pathway is impeded by a shell composed of microscopic hydrophobic isolating agents. Water requires a process to penetrate this shell. This physical impediment creates a time interval between the activation of the second type of beneficial bacteria and the first type of beneficial bacteria. This time interval allows the second type of beneficial bacteria time to expand, thus avoiding instantaneous competition for water and readily available nutrients among all bacterial groups. When the water finally reaches the interior of the shell, the first type of beneficial bacteria, which serves as the core functional group, such as a nitrogen-fixing bacterium, is awakened after the second type of beneficial bacteria has completed preliminary environmental modification. The relationship between the two functional bacteria changes from direct resource competition to a temporal relay.

[0030] Throughout the activation process, the hydrophilic temporary storage agent located at the core of the particle absorbs and locks in moisture, forming a localized high-humidity buffer zone. This zone provides a stable survival environment for the first type of beneficial strains that are sensitive to moisture fluctuations. It should be noted that the operation of this composition does not control the biological characteristics of the strains, but rather the conduction path and rate of moisture within the particle. By pre-constructing the internal physical structure of the particle, the temporal and spatial distribution of the activation signal of moisture is regulated, thus avoiding the problem of strain competition under the new activation sequence. Ultimately, in the early spring sowing season with alternating wet and cold conditions, the fields where this composition was applied developed a stable and functionally diverse microbial community in the rhizosphere of crops, consisting of the second and first types of strains, resulting in more robust growth of crop seedlings. The realization of this process depends on the internal physical partitioning of the particle constructed during the manufacturing process, and the operation of the entire system is driven by the physical interaction between its internal structure and the external environment.

[0031] Example 2: This example aims to quantitatively verify the regulatory effect of granular compositions prepared using different production methods on the activation sequence of multiple microorganisms through controlled experiments. The experiment was conducted on a platform consisting of multiple independent soil microenvironment units. Each unit contained 100 grams of sterilized homogeneous loam, and the initial moisture content was adjusted to 40% of the maximum water holding capacity by adding sterile water to simulate soil conditions with limited moisture. The entire experimental platform was placed at 25°C. In a constant temperature incubator, the experiment consisted of one experimental group and two control groups. The types and initial amounts of the basic fertilizer carrier, hydrophilic temporary storage agent, hydrophobic isolation agent, flexible skeleton agent, and bacterial strains used were all identical. Specifically, Bacillus subtilis was used as the second type of beneficial strain, and Azotobacter brownings was used as the first type of beneficial strain. The initial inoculum amount was the same for both groups. CFU / g dry soil; the experimental group was prepared using the critical hydration self-assembly coating three-step method disclosed in this application; control group A was prepared using a conventional one-step dry mixing and granulation process, in which all components were added to a mixer at once for mixing and granulation; control group B was prepared using the same process as the experimental group, but without the microscopic hydrophobic isolating agent. Soil samples from each group at 0, 12, 24, and 72 hours of culture were analyzed using high-throughput quantitative polymerase chain reaction (qPCR) to obtain the gene copy number of each of the two strains, thereby characterizing their population size. After the start of the experiment, samples were taken at the set time points, and total DNA was extracted using a soil genomic DNA extraction kit. Subsequently, qPCR amplification was performed using specific primers for Bacillus subtilis and Azotobacter brownings, with three replicates for each sample. The number of the two strains in different sample groups was recorded as the logarithm of the gene copy number per gram of dry soil. (Statistical) dynamic change data, see Table 1.

[0032] Table 1: Dynamic changes in the number of two strains under different treatments.

[0033] Table 1 records the population changes of the two strains in different groups. In the experimental group, a clear sequential activation sequence was observed: the number of the second type of strains increased rapidly within 12 hours, while the number of the first type of strains grew sluggishly within the first 12 hours, only beginning to proliferate after 24 hours. In contrast, in control group A, which used a one-step blending process, both strains showed growth within 12 hours, indicating synchronous activation. Subsequently, the number of the first type of strains continued to decline, a phenomenon caused by resource competition between strains. It should be noted that in control group B, where the hydrophobic isolating agent was removed, a similar synchronous activation and subsequent population decline of the first type of strains was reproduced as in control group A. This result isolates and confirms that the shell structure formed by the hydrophobic isolating agent is a key physical element for achieving the sequential activation of strains. In the experimental group, the first type of strains finally reached [a certain number] after 72 hours. The level was higher than that of the two control groups; the experimental data showed that the production method disclosed in this application, namely the core-shell structure constructed inside the particles using the critical hydration self-assembly process, can regulate the activation order of different strains under limited water conditions, transforming the synchronous competition relationship into a temporal relay relationship, thereby ensuring the survival and proliferation of the core functional strains.

[0034] Example 3: This example combines Figs. 1 to 3 This document describes a compound microbial fertilizer synergist that works synergistically with multiple beneficial bacterial strains and its production method. Fig. 1 The diagram illustrates the complete manufacturing process, beginning with the input of raw materials, including a base carrier, a hydrophilic storage agent, and a flexible framework agent. This is followed by a core shaping and toughening step, where critical water is sprayed in to induce gelation of the hydrophilic storage agent surface, forming a viscous micronucleus. Next, in the shell construction step, a hydrophobic isolating agent and core microbial communities are added, utilizing the viscosity of the micronucleus to spontaneously achieve selective encapsulation. Following this, in the matrix filling step, pioneer microbial communities are added to uniformly disperse them in the external space of the core-shell structure. In this step, temperature-gated initiation microcapsules for time-gated initiation can be selectively integrated, capable of initiating at preset temperatures such as 10-20°C. The process involves physical melting to release organic acids and integrating metabolically responsive microcapsules for on-demand supply, which can be triggered by organic acids or metabolites to precisely release functional enhancers, ultimately producing heterogeneous functional particles with a core-shell matrix three-layer microstructure.

[0035] like Fig. 2 As shown in the diagram, the core need of farmers or agricultural technicians as users is to improve crop growth and yield. This is achieved through a series of interconnected functions triggered by the soil environment. Specifically, moisture signals in the soil environment trigger the sequential activation of the microbial community, while temperature signals trigger the on-demand release of functional enhancers. Simultaneously, the system also possesses the ability to purify the local soil environment. Fig. 3 As shown in the figure, the horizontal axis represents time in minutes, and the vertical axis represents water saturation in %; the figure compares the water saturation process of the matrix region, core region, and conventional homogeneous particles of the present invention. The curve representing the particle-matrix region of the present invention and the curve representing conventional homogeneous particles have similar water saturation rates, both showing a rapid upward trend. However, the curve representing the particle-core region of the present invention shows a significant lag in the increase of water saturation, indicating that it takes longer for water to penetrate from the matrix region on the particle surface to the internal core region.

[0036] Example 4: This example provides a key process parameter for determining the production method in a specific implementation, namely the critical water injection rate. The standardized engineering calibration procedure for the work window is designed to address the uncertainties caused by batch-to-batch variations in the physical properties of raw materials such as hydrophilic storage agents and base fertilizer carriers, which affect the critical hydration self-assembly coating process. This calibration procedure aims to determine a specific calibration standard for potassium polyacrylate used as a hydrophilic storage agent in a particular batch. The operating range aims to ensure that the raw material achieves sufficient surface adhesion during production to coat the hydrophobic barrier agent, while preventing the water activity of the entire powder system from exceeding the biological activation water activity threshold of the strain used. The threshold is set to 0.65 in this procedure; the procedure is performed in a laboratory-grade horizontal ribbon mixer equipped with high-precision atomizing nozzles; firstly, based on the inequality relationships disclosed in the specific implementation, the following is calculated: The theoretical guidance range was then determined; subsequently, six groups of dry powder mixture samples were prepared, each containing 1.0 kg of basic fertilizer carrier mixed according to a predetermined formula and the batch of potassium polyacrylate; then, these six groups of samples were sprayed with a gradient of increasing critical water, with the spraying amount set to 90%, 100%, 110%, 120%, 130% and the upper limit of the theoretical range, respectively.

[0037] After the critical water injection is completed, the procedure assesses the process through two parallel quantitative monitoring steps. First, to evaluate the formation and coating efficiency of the gel core, 10 grams of surface-modified iron oxide red powder as a tracer is immediately added to each sample group, and the mixture is stirred continuously for 60 seconds. Afterward, the mixture is sieved using a 20-mesh standard sieve, and the mass of the agglomerates remaining on the sieve is weighed. The ratio of this mass to the initial total dry weight of the sample group is recorded as the gelation coating rate. Second, to monitor the water activity of the system, samples are taken from each sample group after water injection but before the tracer is added, and measured using a water activity meter with a measurement accuracy of ±0.003 to obtain the water activity value of the powder system. The data obtained from this calibration procedure are as follows: When... When the value is 90% of the lower limit of the theoretical range, the gelation coating rate is less than 90%; when When the gelation coverage is between 100% and 120% of the theoretical range, the gelation coverage is greater than 95%, and the corresponding water activity measurements are all below 0.65; when When the upper limit of the theoretical range was reached, the measured water activity value exceeded 0.65; based on the above data, for this specific batch of raw materials, The process window is defined as the range of 100% to 120% of the theoretical lower limit. This calibration procedure transforms a process parameter that depends on the raw material characteristics into a deterministic numerical range that can be executed in production through a reproducible experimental process.

[0038] Example 5: A soil sample contained 1.5 mg / kg of soluble heavy metal cadmium ions ( In the application of this technology, the granular composition used employs calcium polyacrylate as a hydrophilic temporary storage agent. When soil moisture carrying cadmium ions enters the fertilizer granules and is absorbed by the calcium polyacrylate, based on ion exchange selectivity, the carboxylate functional groups on the polymer backbone complex with divalent cadmium ions and fix them, while simultaneously releasing calcium ions. The process involves purifying the chemical environment of the initiation zone before the first type of beneficial strains are activated by water, thus protecting the strains from exposure to high concentrations of harmful ions.

[0039] In another application, the granular composition was applied to northern regions where the soil temperature was 10°C during spring sowing. The composition contains, in combination with, a metabolically responsive microcapsule with a molybdate core and a pH-sensitive chitosan-sodium alginate composite material, and a citric acid powder core and a shell with a melting point set at 15°C. The stearic acid temperature-gated microcapsules; under these low-temperature conditions, even with sufficient soil moisture, the metabolic activity of the revived microorganisms is relatively slow, and the organic acids they produce are insufficient to lower the local pH value below the disintegration threshold of the metabolically responsive microcapsules, thus the functional enhancer remains locked; when the soil temperature rises to 15... At this time, the stearic acid shell of the temperature-gated microcapsule undergoes a physical phase transition and melts, and the citric acid in the core is released into the surrounding hydrogel microenvironment, causing the local pH value to drop rapidly to below 6.0, thereby triggering the disintegration of the metabolic response microcapsule and the release of molybdate. This process couples the release of the functional enhancer with the suitable temperature for active crop growth.

[0040] Example 6: This example aims to provide a standardized engineering optimization procedure for determining the core component ratio of a particulate composition. Its purpose is to define a working window for the key parameter of the mass ratio of the micro-hydrophobic isolator to the hydrophilic temporary storage agent, ensuring that the first type of beneficial strain reaches its maximum survival rate during the sequential activation process with the second type of beneficial strain. In an offline formulation optimization experiment, the technical problem is that the mass ratio of the micro-hydrophobic isolator to the hydrophilic temporary storage agent directly determines the time required for water to penetrate the shell, thus affecting the activation delay time of the first type of beneficial strain. Too short a delay cannot effectively prevent it from avoiding initial resource competition with the second type of beneficial strain, while too long a delay may... This causes the organism to miss the optimal proliferation window; therefore, there exists an optimal ratio range that needs to be determined through systematic experiments. To address this issue, this procedure prepared five sets of test samples. Except for the mass ratio of the micro-hydrophobic isolator to the hydrophilic temporary storage agent, all other components, including the basic fertilizer carrier, flexible framework agent, and the types and initial inoculation amounts of the two strains, were consistent with the test group in Example 2. In these five sets of samples, the mass ratio of the micro-hydrophobic isolator to the hydrophilic temporary storage agent was set to 0.5:1, 1:1, 2:1, 3:1, and 4:1, respectively. Subsequently, these five sets of samples were applied to independent soil microenvironment units that were identical to those in Example 2, with an initial water content of 40% of the maximum water holding capacity, and were tested at 25°C. Cultivation is carried out under specific conditions.

[0041] During the execution of this procedure, the sole endpoint determination criterion was the measurement of the final population size of the first-class beneficial bacteria in each group of soil samples using high-throughput quantitative polymerase chain reaction (PCR) technology after 72 hours of incubation. The procedure aimed to identify the objective function—the parameter point corresponding to maximizing the survival rate of the first-class beneficial bacteria—by monitoring the trend of this single performance index with varying ratio parameters. After 72 hours of incubation, the number of first-class beneficial bacteria in each group of samples was measured as follows: , , , and CFU / g dry soil; Analysis of the data obtained from this optimization procedure showed that when the mass ratio of the micro-hydrophobic isolator to the hydrophilic temporary storage agent was 0.5:1, the final number of the first type of beneficial strains was low, indicating that the activation delay obtained was insufficient to avoid competition. As the ratio increased, the final number of the first type of beneficial strains continued to rise, reaching a peak at a ratio of 2:1. When the ratio further increased to 4:1, the final number began to decrease slightly, indicating that the excessively thick hydrophobic shell may have hindered the final penetration of water to some extent. Therefore, for this specific component and strain system, the preferred mass ratio range of the micro-hydrophobic isolator to the hydrophilic temporary storage agent was determined to be between 2:1 and 3:1. This procedure transformed a key formulation parameter affecting the synergistic effect of strains into an optimal numerical range with clear engineering basis through a performance-oriented optimization experiment.

[0042] To further verify from the reverse perspective the decisive role of the three-step self-assembly coating method of critical hydration disclosed in this invention in constructing heterogeneous structures inside particles and thereby achieving temporal activation of the microbial community, the following comparative examples are provided.

[0043] Comparative Example 1: This comparative example aims to verify the actual impact on the activation sequence of multiple microorganisms and the final survival rate of core functional strains when using the exact same material composition and initial addition amount as in Example 2, instead of employing a three-step sequential feeding procedure to construct a heterogeneous internal structure of the granules, a one-step blending homogenization dry granulation process is used. In the preparation of this comparative example, all materials used in the experimental group of Example 2, including the basic fertilizer carrier, hydrophilic temporary storage agent, micro-hydrophobic isolation agent, flexible skeleton agent, and dormant Bacillus subtilis (as a second type of beneficial strain) and dormant Azotobacter brownings (as a first type of beneficial strain), were all added to a horizontal ribbon mixer at once. Subsequently, dry blending was carried out at a speed of 30-50 rpm for 5 minutes to ensure that all components achieved statistically uniform distribution. The mixed material was then transferred to an extrusion granulator for granulation through a template with a pore size of 2-4 mm, and the granulation was carried out at a speed below 40 rpm. The mixture was dried at low temperature under controlled conditions until the final product had a moisture content of less than 5%, resulting in a granular composition. The internal components of the resulting granules exhibited a physically homogeneous distribution. The granular composition prepared using this comparative method was tested under the same controlled experimental conditions as in Example 2, i.e., it was applied to sterilized soil with an initial moisture content of 40% of the maximum water holding capacity and dried at 25°C. Cultured under constant temperature conditions, with an initial inoculum size of [missing information]. CFU / gram of dry soil was collected at 0, 12, 24, and 72 hours of incubation. The gene copy number of each of the two strains was measured using quantitative polymerase chain reaction (qPCR). The number of each strain in the sample group prepared using this comparative example was recorded as the logarithm of the gene copy number per gram of dry soil. (Statistical) dynamic change data, see Table 2.

[0044] Table 2: Dynamic changes in the number of two strains in the sample group prepared using the conventional one-step blending process.

[0045] Experimental data show that in the sample group prepared using the conventional one-step blending process, the number of both the second and first strains increased within the first 12 hours, and their activation process was synchronous. However, after 24 hours, the population of the first strain, which is the core functional group, began to decline sharply, and after 72 hours, it declined to below the initial inoculation level. This indicates that it was suppressed in direct resource competition with the second strain, which has a greater growth advantage, and eventually died in large numbers. This result objectively confirms that, in the absence of the core-shell physical partitioning structure constructed by the specific process of this invention, with hydrophobic isolating agents as the core, even if all beneficial components are present in the system, it is impossible to avoid the competitive internal consumption caused by the synchronous activation of strains. As a result, the survival and proliferation of the core functional strains cannot be guaranteed, and the advantages of the strain diversity in the formulation design cannot be effectively utilized.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0047] Finally, 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 it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A compound microbial fertilizer synergist that synergizes with multiple beneficial bacterial strains, characterized in that, The synergist is a particulate composition comprising multiple functional zones, the particulate composition being prepared by a method comprising the following steps: Step a: The organic powder, which serves as the base fertilizer carrier, is mixed with a dry, highly absorbent polymer, which serves as a hydrophilic temporary storage agent, and a lignin sulfonate, which serves as a flexible skeleton agent, in a mixing device; then, liquid water is sprayed into the continuously stirred mixed powder, and the amount of liquid water sprayed is set within a critical range. Step b: Add a micro-hydrophobic isolating agent and at least one type of dormant bacterial agent of a first-class beneficial strain to the mixing device. Driven by the physicochemical force gradient between the hydrophobic isolating agent and the surface of the discrete gel core, the hydrophobic isolating agent and the first-class bacterial agent spontaneously and selectively adhere to and coat the surface of the discrete gel core, thereby constructing multiple core-shell structure precursors with the discrete gel core as the core and the hydrophobic isolating agent and the first-class bacterial agent as the shell at the micro-scale. Step c: Add at least one dormant bacterial agent of a second type of beneficial strain to the mixing device and mix, so that the second type of bacterial agent is dispersed in the outer space of the core-shell structure precursor composed of the basic fertilizer carrier.

2. The compound microbial fertilizer synergist according to claim 1, characterized in that, The amount of liquid water injected in step a It is bound by a rule directly related to the physical properties of superabsorbent polymers and the biological characteristics of beneficial strains, which is defined by the following inequality: in, This is the dry weight of the superabsorbent polymer; This is a preset minimum water absorption ratio coefficient based on the material specifications of a superabsorbent polymer, which is required to achieve surface swelling and gelation. The total dry weight of the mixed powder; A biological activation water activity threshold is preset based on the characteristics of various beneficial strains; This is the molar mass of water.

3. The compound microbial fertilizer synergist according to claim 1, characterized in that, The hydrophilic temporary storage agent is sodium polyacrylate, potassium polyacrylate, or calcium polyacrylate; the micro-hydrophobic isolation agent is diatomaceous earth modified with silane or fatty acid; the basic fertilizer carrier is humic acid powder or peat powder; and the flexible skeleton agent is lignin sulfonate. In the dry state of the composition, the lignin sulfonate forms a flexible polymer network by interweaving its macromolecular chains with the basic fertilizer carrier and other components. When the composition is exposed to water, the lignin sulfonate located on the microcrack walls absorbs water and swells to form a high-viscosity gel.

4. The compound microbial fertilizer synergist according to claim 1, characterized in that, The hydrophilic temporary storage agent is selected as calcium polyacrylate or potassium polyacrylate. When water carrying heavy metal ions in the form of polyvalent cationic forms enters the composition and is absorbed by the hydrophilic temporary storage agent, the hydrophilic temporary storage agent captures and fixes the heavy metal ions through ion exchange, while releasing calcium or potassium ions into the hydrogel microenvironment formed therein.

5. The compound microbial fertilizer synergist according to claim 1, characterized in that, The composition also includes a metabolically responsive microcapsule; the metabolically responsive microcapsule has a core encapsulating a functional enhancer and a shell made of a material that is sensitive to changes in the micro-regional chemical environment caused by the metabolic products of a first or second type of beneficial strain after it is activated by water and enters an active metabolic state.

6. The compound microbial fertilizer synergist according to claim 5, characterized in that, The change in the micro-region chemical environment is a decrease in pH value; the shell of the metabolic response microcapsule is a composite material of chitosan and sodium alginate, which is stable in a neutral or weakly alkaline environment and disintegrates in an acidic environment with a pH value below 6.0; the functional enhancer is molybdate, cobalt salt, quorum sensing inducer or pre-set amino acid precursor.

7. The compound microbial fertilizer synergist according to claim 6, characterized in that, The composition also includes a temperature-gated start-up microcapsule; the temperature-gated start-up microcapsule has a core encapsulated with a solid organic acid and a shell made of a phase change material having a preset melting point set in the range of 10 degrees Celsius to 20 degrees Celsius.

8. The compound microbial fertilizer synergist according to claim 7, characterized in that, The solid organic acid is citric acid micropowder; the phase change material is stearic acid or palmitic acid; when the ambient temperature reaches the preset melting point, the outer shell melts and releases the solid organic acid. The solid organic acid acts as an exogenous chemical signal, triggering the disintegration of the outer shell of the metabolic response microcapsule.

9. The compound microbial fertilizer synergist according to claim 1, characterized in that, The granular composition has a physically heterogeneous structure at the microscale, comprising: a core composed of a highly absorbent polymer; a shell coating the surface of the core composed of a micro-hydrophobic isolating agent and a first type of beneficial strain; and a matrix filling the external space of the core-shell structure precursor composed of a basic fertilizer carrier, lignin sulfonate and a second type of beneficial strain.

10. A method for producing a compound microbial fertilizer synergist that synergizes with multiple beneficial strains, characterized in that, Includes the following steps: Step a: The organic powder, which serves as the base fertilizer carrier, the dried superabsorbent polymer, which serves as a hydrophilic temporary storage agent, and the lignin sulfonate, which serves as a flexible skeleton agent, are mixed in a mixing device; then, liquid water within a critical range is sprayed into the continuously stirred mixed powder to induce swelling and gelation of the surface of the superabsorbent polymer, thereby forming multiple discrete gel cores with surface adhesion, while ensuring that the water activity of the entire powder system is below the biological activation threshold of the beneficial strains. Step b: Add a microscopic hydrophobic isolating agent and at least one type of dormant bacterial agent of a first-class beneficial strain to the mixing device. Utilize the surface adhesion of the discrete gel core to drive the hydrophobic isolating agent and the first-class bacterial agent to spontaneously and selectively adhere to and coat the surface of the discrete gel core, thereby constructing multiple core-shell structure precursors at the microscale, with the discrete gel core as the core and the hydrophobic isolating agent and the first-class bacterial agent as the shell. Step c: Add at least one dormant bacterial agent of a second type of beneficial strain to the mixing device and mix to disperse the second type of bacterial agent in the external space of the core-shell structure precursor composed of the basic fertilizer carrier, and finally obtain the granular composition.

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