A composite biosynergist, its preparation method and its application

Abstract

This invention provides a composite biosynergist, its preparation method, and its application. The composite biosynergist is composed of polyglutamic acid, humic acid, fucoidan oligosaccharide, and plant polyphenols. The synergistic effect of the active substances polyglutamic acid γ-PGA, humic acid HA, fucoidan oligosaccharide AOS, and plant polyphenol PP in the composite biosynergist is essentially manifested in microscopic-scale functional complementarity and mechanism closed-loop. It achieves four functional pathways: blocking salt toxicity through chelate channels, ensuring nutrient supply through complexation channels, enhancing nutrient absorption through root-promoting channels, and resisting stress damage through stress-resistant channels. Ultimately, it achieves the macroscopic effect of "improved soil physicochemical properties—enhanced root function—increased crop stress resistance and yield." Its core advantage lies in overcoming the functional limitations of single components and solving the industry pain points of "difficult-to-eliminate salt damage, easy nutrient loss, and unstable improvement effect" in saline-alkali land improvement through molecular-level synergistic effects.

Description

Technical Field

[0001] This invention belongs to the field of agricultural environmental management and soil remediation technology, specifically relating to a compound biological synergist, its preparation method, and its application in the improvement of saline-alkali land. Background Technology

[0002] Saline-alkali land management is a major strategic need to ensure national food security, improve arable land quality, and enhance the regional ecological environment. Traditional methods for saline-alkali land management (such as soil replacement, flood irrigation to leach salt, and application of chemical amendments like gypsum / phosphogypsum) can alleviate salinity hazards in the short term, but they generally suffer from large engineering workloads, high costs, and the potential to cause secondary pollution and damage to soil aggregate structure, making sustainable ecological restoration of saline-alkali land difficult. In recent years, with the deepening of the green development concept, biological improvement technologies have become a research hotspot due to their environmental friendliness, ecological sustainability, and multiple synergistic effects. Currently, various technical routes have emerged in this field, but significant shortcomings still exist: Microbial soil conditioners: Patent CN117964421A provides an synergistic soil conditioner for saline-alkali soils, which integrates earthworm castings fermentation liquid, compound probiotic microcapsules (coated with carboxymethyl cellulose and sodium alginate), modified zeolite-vermiculite composite material, and modified chitosan. The technology is relatively complex, and the cost-effectiveness needs to be optimized. The long-term field effect needs further verification. Patent CN202311365494.9 developed a compound liquid microbial agent containing multiple functional microorganisms such as Bifidobacterium longum, Bacillus amyloliquefaciens, and Bacillus subtilis, supplemented with earthworm castings extract and biostimulants such as sugars. However, the survival and colonization efficiency of the microbial agent under extreme saline-alkali conditions is very low.

[0003] Composite chemical / mineral-based modifiers: Patent CN105131962A uses a reverse microcapsule suspension emulsion as a modifier, containing water-soluble calcium, inorganic nutrients, and surfactants, but the preparation process involves multiple chemicals and specific techniques. Patent CN115725303A utilizes a compound modifier made from coal-water slurry gasification slag, polyacrylamide, wood vinegar, and diatomaceous earth, but its effectiveness is significantly affected by the stability of byproduct components.

[0004] Multifunctional compound agents: CN202311064691.7 designed a multifunctional compound agent composed of a seed soaking and root strengthening agent, an isolation and retardation agent, a low molecular weight acid-alcohol mixture, a carboxylic acid and glycerol mixture, and a humic acid mixture. However, the application process is relatively complex and requires precise calculation and operation.

[0005] Furthermore, research on biostimulants derived from halophytes and seaweed has provided new insights into the improvement of saline-alkali land. For example, nanoparticles (NPs) and biostimulants derived from halophytes have been reported to enhance crop stress resistance through mechanisms such as strengthening antioxidant defense, regulating osmotic balance, and promoting nutrient absorption. However, this technology is limited to the experimental stage; optimal application parameters under field conditions need to be explored, and batch stability and long-term safety assessment systems need to be improved.

[0006] Therefore, developing a new technology for the comprehensive improvement of saline-alkali land that can significantly improve the survival rate and colonization efficiency of functional microorganisms under saline-alkali stress, ensure the long-term stability of the improvement effect, optimize cost-effectiveness, and be deeply integrated with intelligent water and fertilizer management systems, while also revealing the interaction mechanism of biostimulants-microorganisms-plants, has important theoretical value and practical significance. Summary of the Invention

[0007] This research, based on the aforementioned background needs, utilizes innovative technical approaches to precisely address numerous shortcomings in existing technologies, promoting the development of saline-alkali land management technology towards a more efficient, economical, and sustainable direction. This invention proposes an integrated "biological-water-salt-crop" solution for the systematic management of saline-alkali land. The invention discloses a composite biological synergist, which forms a closed-loop control system with precision irrigation and drainage and simplified monitoring. The composite biological synergist is primarily composed of polyglutamic acid, humic acid, seaweed-derived oligosaccharides, and plant polyphenols. Through a multi-channel synergistic effect of "chelation—complexation—root promotion—stress resistance," it addresses the triple objectives of soil physicochemical improvement, microecological restoration, and slow-release of nutrients from crop stress. Its preparation process adheres to the principles of green, safe, and scalable production, and can be directly integrated into existing fertilizer and fertilization procedures. In terms of application, this solution emphasizes coupling with water-saving irrigation methods such as drip irrigation under mulch. Through periodic rereading of lightweight indicators such as soil conductivity and soil moisture, it coordinates and adjusts the water-fertilizer ratio, irrigation frequency, and application window to achieve targeted regulation of water and salt migration and continuous optimization of the rhizosphere environment. The overall technical effects of this solution are reflected in: alleviating soil salinity accumulation, improving soil aggregate structure and permeability, enhancing organic matter and water retention capacity, and simultaneously improving crop tolerance to salt stress and nutrient utilization efficiency, thereby achieving stable yield and increased efficiency without increasing environmental burden. The application method of this invention has the advantages of high compatibility with conventional base fertilizers and drip irrigation systems, scalable parameters, and simple operation and maintenance. It is suitable for regional promotion in typical saline-alkali farmland (such as cotton fields) and other dry and salt-sensitive areas. The formula and management rhythm can be adaptively adjusted according to monitoring feedback results for different salinity levels and crop types, demonstrating good engineering replicability and industrialization prospects.

[0008] Specifically, the composite biosynergist of the present invention is composed of polyglutamic acid (γ-PGA), humic acid (HA), alginate (AOS), and plant polyphenols (PP).

[0009] γ-PGA is a linear polymer compound containing a large number of carboxyl groups (-COO) in its molecular structure. - Not only does it possess strong hydrophilicity, but it also provides dense negative charge sites, enabling efficient chelation of salt ions. Simultaneously, γ-PGA can form a gel structure, which protects AOS from degradation, fixes soil moisture and nutrients, and provides a carbon source for microorganisms. HA, an aromatic polymer, is rich in carboxyl, phenolic hydroxyl, and quinone functional groups. Its porous structure adsorbs salt ions and nutrients, serving as a carbon source for microorganisms, promoting metabolism, regulating rhizosphere pH, and protecting root functional groups. AOS, a low-molecular-weight polysaccharide, can act as a signaling molecule to trigger plant gene expression, thereby promoting root growth and enhancing crop resistance. Furthermore, AOS can regulate the microbial community structure and enhance the decomposition and utilization efficiency of HA / γ-PGA. PP molecules contain multiple phenolic hydroxyl groups, exhibiting strong antioxidant and complexing capabilities. On one hand, it can scavenge free radicals; on the other hand, it effectively protects HA / γ-PGA functional groups from oxidation, forming hydrogen bonds / hydrophobic interactions with HA / γ-PGA to enhance system stability.

[0010] The four components, γ-PGA, HA, AOS, and PP, form a cross-scale composite system through the synergistic effects of covalent bonds, coordination bonds, and hydrogen bonds. Specifically, the γ-PGA polymer chain acts as the "skeleton" of the composite system, the multifunctional groups of HA and the phenolic hydroxyl groups of PP act as "active nodes," and AOS acts as a "signal molecule" embedded in the system. This not only enhances the adsorption / chelation capacity for salt ions and nutrients but also prolongs the action time of the signal molecule. At the same time, the improvement effect is further amplified through microbial metabolism.

[0011] Furthermore, the proportions of each component by weight are as follows: polyglutamic acid, humic acid, alginic oligosaccharides and plant polyphenols = (15~25) : (40~60) : (5~15) : (10~20).

[0012] The present invention also provides a method for preparing the composite biosynergist as described above, specifically including the following steps: mixing polyglutamic acid, humic acid, fucoidan oligosaccharide and plant polyphenols by physical dry mixing, solvent soaking or mechanical stirring, drying the resulting mixture at 40-50°C for 8-12 hours, and then pulverizing it to a particle size of 50-200 μm to obtain the composite biosynergist.

[0013] Furthermore, the physical dry mixing method refers to placing polyglutamic acid, humic acid, fucoidan oligosaccharide and plant polyphenols in a mixer and dry mixing them at a speed of 15-60 rpm for 20-30 minutes.

[0014] Furthermore, the solvent immersion method refers to using water or food-grade / pharmaceutical-grade non-toxic solvents (such as ethanol or propylene glycol) as the dispersion medium, with the amount of solvent added being 2%-5% of the total weight of polyglutamic acid, humic acid, alginic oligosaccharides, and plant polyphenols, and immersion at 15-40°C for 2-4 hours.

[0015] Furthermore, the mechanical stirring method refers to mixing polyglutamic acid, humic acid, fucoidan oligosaccharides and plant polyphenols with water or the above solvent at a mass ratio of 1:100~300, and mixing at a stirring speed of 500~1500 rpm for 30-60 minutes.

[0016] Furthermore, in the mechanical stirring method, the total mass ratio of polyglutamic acid, humic acid, fucoidan and plant polyphenols to water or solvent is 1:100 to 1:300.

[0017] The preparation method does not use any harmful chemical solvents throughout the process, thus ensuring the environmental friendliness and safety of the resulting composite biosynergist.

[0018] This invention also provides an application of the aforementioned compound biosynergist in saline-alkali land.

[0019] Furthermore, the present invention provides an application of the aforementioned compound biological synergist in improving saline-alkali land and promoting the growth of plants in saline-alkali land.

[0020] Targeting free Na in saline soil + Cl - The present invention addresses the problems of osmotic stress and ion toxicity in plants caused by chelation, through a multi-channel synergistic effect of "chelation salt - complexation - root promotion - stress resistance", and achieves good application of the compound bio-synergist in saline-alkali land.

[0021] First, the chelation and fixation of harmful salt ions; Site-specific co-capture: Carboxyl group (-COO) of γ-PGA - The carboxyl and phenolic hydroxyl groups of HA provide dense negative charge sites, which coordinate with Na. + Ca 2+ The isocations combine to form a stable "γ-PGA-HA-Na" + "Chelates; the phenolic hydroxyl groups of PP adsorb Cl through hydrogen bonds." - Or through hydrophobic interactions to encapsulate Cl - This reduces its free concentration in the soil solution.

[0022] Spatial barrier and migration: The gel structure of γ-PGA chelates Na +It is "locked" in the polymer network to prevent diffusion into the rhizosphere; the porous structure of HA adsorbs chelates, forming a dual barrier of "adsorption-fixation"; AOS promotes the secretion of protons (H2O) from plant roots. + ), via H + -Na + The exchange pump removes residual Na from the rhizosphere + Pumping into deeper soil layers further reduces the risk of surface salt accumulation.

[0023] Synergistic advantage: A single component (such as HA) can only adsorb a small amount of Na. + The polymer chains of γ-PGA can "entangle" multiple Na+ molecules. + PP enhances the stability of chelates, and the three work synergistically to increase the salt ion chelation capacity by more than 30%, significantly reducing the osmotic pressure of the soil solution.

[0024] Second, complexing channels: stabilize nutrient forms and enhance bioavailability; To address the issue of soil nutrients such as nitrogen (N), phosphorus (P), potassium (K), and iron (Fe) being easily chemically fixed (e.g., phosphorus forming insoluble calcium phosphate) or leached, the mechanism of synergistic complexation is: Targeted complexation: Quinone groups in humic acid (HA) react with ammonium nitrogen (NH4+). + Complexation reduces its volatilization as ammonia (NH3); the carboxyl group of γ-PGA is linked by Ca... 2+ / Mg 2+ Bridging with phosphate (PO4) 3- This forms a stable "γ-PGA-Ca-PO4" complex, inhibiting phosphorus (P) fixation; the phenolic hydroxyl groups of plant polyphenols (PP) can react with Fe. 2+ Zn 2+ Trace elements are chelated to prevent them from being oxidized or precipitated and deactivated.

[0025] Slow Release and Activation: The gel network of polyglutamic acid (γ-PGA) can physically encapsulate complexed nutrients, and humic acid (HA) further acts as a porous carrier to adsorb these encapsulated systems, thereby achieving slow release of nutrients; at the same time, alginate oligosaccharides (AOS) promote the secretion of organic acids such as citric acid and malic acid by plant roots, dissolving complexed nutrients (such as dissociating PO4). 3- It is absorbed through transport proteins on the root cell membrane (such as PHT1 phosphotransporter).

[0026] Microbial assistance: Humic acid (HA) and polyglutamic acid (γ-PGA) provide carbon sources for phosphate-solubilizing bacteria and nitrogen-fixing bacteria. Their metabolites (such as amino acids) further enhance the stability of nutrient complexation, while converting insoluble nutrients into soluble forms, forming a synergistic effect of "chemical complexation + microbial activation".

[0027] Third, root-promoting pathways: signal regulation + environmental optimization, enhancing root absorption function; The root system is the core of soil-plant material exchange, and the microscopic mechanism for synergistic root promotion is: Signaling molecules trigger gene expression: Alginate (AOS) can be recognized by plants as "signaling molecules" and bind to receptors (such as kinase receptors) on root cell membranes, activating the MAPK signaling pathway, upregulating the expression of auxin synthesis gene (YUC) and cytokinin gene (IPT), promoting the synthesis of auxin (IAA) and cytokinin, accelerating cell division in the root tip meristem and cell elongation in the elongation zone, and increasing the number of root hairs and root surface area.

[0028] The rhizosphere environment optimization mechanism utilizes the gel structure of polyglutamic acid (γ-PGA) to maintain high humidity in the rhizosphere soil (increasing water content by more than 20%), providing a suitable water environment for root growth. Humic acid (HA) regulates the rhizosphere pH to 7.5-9.0 (the suitable range for cotton growth), preventing high pH from damaging ion channels on root cell membranes. Plant polyphenols (PP) inhibit the mycelial growth of harmful rhizosphere fungi (such as Fusarium) and protect root epidermal cells from infection.

[0029] Nutritional supply: Glutamic acid, produced by the decomposition of polyglutamic acid (γ-PGA), is an essential amino acid for plants and can be directly absorbed by the roots, promoting protein synthesis in root cells; Small molecule organic acids (such as humic acid fragments) produced by the decomposition of humic acid (HA) provide energy metabolism substrates for the roots and enhance root respiration.

[0030] Fourth, the stress resistance pathway: oxidative protection + osmotic regulation enhances salt stress tolerance; Under salt stress, when plants produce reactive oxygen species (ROS) and experience cell dehydration, this compound synergist enhances plant tolerance through the following synergistic mechanism: Synergistic antioxidant defense: The phenolic hydroxyl groups of plant polyphenols (PP) act as electron donors, rapidly scavenging ROS (such as O2) within root and leaf cells. - It can inhibit lipid peroxidation (reducing MDA content) and protect cell membrane integrity; alginate oligosaccharides (AOS) upregulate the expression of antioxidant enzyme genes (SOD, POD, CAT), enhance the activity of the plant's own antioxidant system, and can also form a dual protection of "exogenous antioxidant + endogenous antioxidant" with plant polyphenols (PP).

[0031] Osmotic balance regulation: The high hydrophilicity of polyglutamic acid (γ-PGA) forms a hydration layer outside the cell, reducing the osmotic potential difference between the inside and outside of the cell and alleviating dehydration stress; humic acid (HA) induces plants to synthesize osmotic regulators such as proline and betaine, which regulate intracellular osmotic pressure, enabling plants to absorb more water from the soil; polyglutamic acid (γ-PGA) chelates potassium... +Absorbed by the root system, maintaining intracellular potassium + / Na + Balance (K) + It is a key ion for maintaining enzyme activity and cell membrane stability, reducing Na+ + Inhibition of photosynthetic enzymes (such as Rubisco).

[0032] Microbial-assisted stress resistance: Polyglutamic acid (γ-PGA) and alginate oligosaccharides (AOS) can promote the reproduction of beneficial microorganisms (such as Bacillus), and the gibberellins, salicylic acid and other substances secreted by them can activate plant defense genes and further enhance stress resistance.

[0033] Furthermore, the specific application steps are as follows: Step S1: Apply compound biological synergist to saline-alkali soil at a rate of 20-25 kg / hm². Step S2: Irrigation regulation is carried out using drip irrigation under mulch to optimize water and salt management.

[0034] The aforementioned compound bio-enhancing agent can increase soil organic matter content, improve soil structure, reduce soil salinity, and enhance crop resistance, making it particularly suitable for saline-alkali cotton fields for the following reasons: 1. Alleviate surface salt accumulation and block the upward pathway of salt ions: ① The synergistic chelation of polyglutamic acid (γ-PGA), humic acid (HA), and plant polyphenols (PP) significantly reduces the concentration of free salt ions in the soil solution and decreases the number of salt ions that rise with water vapor evaporation; ② The gel structure of polyglutamic acid (γ-PGA) and the porous structure of humic acid (HA) enhance soil water retention, reduce the surface water evaporation rate (evaporation is reduced by more than 25%), and weaken the upward movement of salt ions; ③ The improved aggregate structure increases soil porosity, promotes irrigation water infiltration, and carries chelated salt ions to deeper soil layers below 100 cm, preventing their accumulation on the surface; ④ Alginate (AOS) promotes deep root growth, increases deep water absorption, further reduces surface evaporation, and forms a cycle of "water retention-infiltration-deep absorption".

[0035] 2. Improve soil aggregate structure and permeability, and construct a soil particle cementation network: ① Cementation Bridge Formation: The aromatic skeleton of humic acid (HA) and the polymer chain of polyglutamic acid (γ-PGA) bind to the hydroxyl groups on the surface of soil clay particles (montmorillonite, kaolinite) through ionic / hydrogen bonds, binding dispersed soil particles into micro-aggregates. The phenolic hydroxyl groups of plant polyphenols (PP) form cross-linked structures with humic acid (HA) and polyglutamic acid (γ-PGA), enhancing the strength of the cementation bridges and preventing aggregate dispersion. ② Microbial-Assisted Cementation: Humic acid (HA) and polyglutamic acid (γ-PGA) provide carbon sources for microorganisms. The polysaccharides and mucus produced by their metabolism (such as extracellular polymeric substances (EPS)) are natural cementing agents for soil particles, further strengthening the aggregate structure. ③ Pore formation: After the formation of aggregate structure, a large number of aeration pores (diameter > 0.02 mm) and capillary pores (diameter 0.002-0.02 mm) appear in the soil. Aeration pores improve gas exchange, and capillary pores enhance water conduction, thereby improving soil permeability (increasing the permeability rate by more than 40%) and avoiding compaction.

[0036] 3. Enhances the body's ability to retain organic matter and moisture; organic replenishment + structural water-locking: Enhancing Organic Matter: ① Humic acid (HA), polyglutamic acid (γ-PGA), alginate (AOS), and plant polyphenols (PP) are all organic materials that can directly replenish soil organic matter after application. ② Indirect Transformation: Humic acid (HA) and polyglutamic acid (γ-PGA), as carbon sources for microorganisms, promote the reproduction of microbial communities and encourage microorganisms to decompose soil residues to produce more humic substances (such as humic acid and fulvic acid), forming a synergistic effect of "direct replenishment + microbial transformation," which increases organic matter content by more than 20%.

[0037] Moisture retention: ① Polyglutamic acid (γ-PGA) polymer chains contain a large number of hydrophilic groups, which can absorb 50-100 times its own weight in water to form a hydrated gel, converting free water into bound water; ② The nanoscale pores of humic acid (HA) adsorb water through capillary action, forming a "miniature reservoir"; ③ The capillary pores of the aggregate structure distribute water evenly, reducing leakage and evaporation; the three factors work together to increase soil water holding capacity by more than 30%.

[0038] 4. Improve crop salt stress tolerance and nutrient utilization efficiency, and optimize cellular functions: Salt stress tolerance: ① Chelate channels reduce intracellular Na+ + Concentration, complexation channels increase K + Ca 2+ Absorption, maintaining K + / Na +① Balance and protect the normal function of ion channels (such as SOS1) on the cell membrane; ② Humic acid (HA) and alginate oligosaccharides (AOS) induce the synthesis of proline and betaine, reduce intracellular osmotic potential, and alleviate dehydration; ③ Plant polyphenols (PP) scavenge ROS in leaves, prevent chlorophyll from being oxidized, and alginate oligosaccharides (AOS) upregulate the expression of photosynthetic enzyme genes, maintain photosynthetic efficiency, and provide energy for stress resistance.

[0039] Nutrient utilization efficiency: ① Complexation channels fix nutrients in a stable form, preventing leaching / volatilization (e.g., NH3 volatilization is reduced by 25%); ② Alginate oligosaccharides (AOS) promote the expression of root transport proteins (e.g., PHT1, NRT1), increasing nutrient absorption sites; ③ Phosphate-solubilizing bacteria convert insoluble phosphorus into soluble form, and nitrogen-fixing bacteria fix N2 in the air, further supplementing available nutrients and increasing fertilizer utilization by more than 30%.

[0040] Furthermore, in step S2, for moderately saline-alkali soils with an average salt content of 4-10 g / kg in the 0-100cm soil layer, the irrigation quota is between 4000 m³ / hm² and 5000 m³ / hm²; for severely saline-alkali soils with an average salt content greater than 10 g / kg in the 0-100cm soil layer, the irrigation quota is between 4500 m³ / hm² and 6000 m³ / hm².

[0041] Furthermore, drip irrigation under mulch film utilizes the synergistic effect of drip tape and specialized drip heads to distribute water, ensuring even penetration of irrigation water into the root zone. When used in conjunction with a compound bio-synergist, drip irrigation under mulch film can achieve optimal water use efficiency and crop growth by synergistically regulating the water-to-fertilizer ratio, irrigation time, and frequency. The compound synergist improves soil structure and water retention capacity, reduces salt accumulation, and enhances irrigation water permeability, thereby optimizing the water-to-fertilizer ratio, irrigation time, and frequency, improving water use efficiency, and enhancing crop growth.

[0042] This invention also provides an agricultural water and fertilizer management system, comprising: a compound bio-enhancing agent application unit as described above, used to uniformly apply the compound bio-enhancing agent into the soil; a water source management unit, including a drip irrigation system under mulch and an irrigation control device; a monitoring and feedback unit, used to monitor data such as soil electrical conductivity (EC), soil moisture content, and crop growth status in real time; and a control unit, used to automatically adjust irrigation and application rates based on the monitoring data. The control unit can achieve remote monitoring and data optimization through wireless sensors and a data analysis platform to improve management efficiency. This enables coordinated optimization of the irrigation and enhancing agent application processes, improving water and fertilizer use efficiency, reducing salt accumulation, and promoting healthy crop growth.

[0043] The yield increase was 15% to 20% in moderately saline-alkali land and 25% to 30% in severely saline-alkali land; and the crop quality, including fiber length, single boll weight, lint percentage and other indicators, was significantly improved.

[0044] The system has adaptive adjustment capabilities, and can automatically adjust the water and nutrient supply ratio and application cycle according to different growth stages of crops and types of saline-alkali land.

[0045] Compared with the prior art, the present invention has the following outstanding features and advantages: The active substances polyglutamic acid (γ-PGA), humic acid (HA), alginate oligosaccharides (AOS), and plant polyphenols (PP) in this invention's compound biosynergist are essentially based on "microscopic functional complementarity and closed-loop mechanism." Through chelate channels blocking salt toxicity, complexation channels ensuring nutrient supply, root-promoting channels enhancing nutrient absorption, and stress-resistance channels resisting stress damage, it ultimately achieves the macroscopic effect of "improved soil physicochemical properties—enhanced root function—increased crop stress resistance and yield." Its core advantage lies in overcoming the functional limitations of single components and solving the industry pain points of "difficult-to-eliminate salt damage, easy nutrient loss, and unstable improvement effects" in saline-alkali land improvement through molecular-level synergistic effects. Specifically: 1. Multi-party collaboration and intelligent regulation: This invention innovatively combines four biostimulants—polyglutamic acid, humic acid, fucoidan oligosaccharides, and plant polyphenols—in a scientifically formulated ratio, producing a synergistic effect of "1+1>2." This significantly improves soil organic matter and aggregate structure, while also deeply integrating biological improvement with an intelligent water and fertilizer management system. By monitoring soil data in real time, it automatically and precisely controls irrigation and application rates, achieving coordinated and intelligent management of water, salt, and fertilizer, fundamentally solving the industry problem of unstable improvement effects.

[0046] 2. Improve efficiency, increase production and enhance quality: This invention exhibits remarkably significant improvement effects, effectively reducing soil salinity by 25-40% and substantially increasing water and fertilizer use efficiency by over 30%. Its ultimate impact is directly reflected in higher crop yields and improved crop quality, achieving yield increases of 15-20% and 25-30% in moderately and severely saline-alkali land, respectively. It also significantly improves quality indicators such as the average length of the upper portion and breaking strength of crops like cotton, demonstrating outstanding economic value.

[0047] 3. Environmentally friendly, labor-saving and cost-effective: This invention employs green preparation processes such as physical dry mixing throughout the entire process, without using any harmful chemical solvents, resulting in an environmentally friendly product. Furthermore, this technology can reduce fertilizer usage by 15-20% and achieves automated operation through intelligent equipment, reducing labor costs by over 40%. It is a sustainable solution that combines ecological and economic benefits. Attached Figure Description

[0048] Figure 1 This is a schematic diagram illustrating the preparation and application of the composite biosynergist of the present invention. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments only illustrate a portion of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The technical solutions of the present invention will be further described below with reference to implementation examples.

[0050] Example 1 See Figure 1 This embodiment provides an application of a compound bio-enhancing agent in moderately saline-alkali cotton fields. Specifically, an experiment was conducted in a typical moderately saline-alkali cotton field in Shihezi, Xinjiang (average salt content of 7.8 g / kg in the 0–100 cm soil layer, pH 8.6, and organic matter 1.2%).

[0051] In this embodiment, the compound biosynergist was formulated with a ratio of γ-PGA : HA : AOS : PP = 20 : 50 : 10 : 15. The mixture was prepared by physical dry mixing in a 45 rpm mixer for 30 minutes, then dried at 45 °C for 10 hours and pulverized to 100 μm. The synergist was applied at a rate of 22 kg / hm², and mixed with 150 kg / hm² of urea and 50 kg / hm² of potassium dihydrogen phosphate as a base fertilizer.

[0052] Irrigation was carried out using drip irrigation under mulch, with a total annual quota of 4500 m³ / hm², completed in 5 applications. The irrigation cycle and water-fertilizer ratio were adjusted in real time using soil conductivity and soil moisture monitoring, as shown in Table 1. After one growing season, soil salinity decreased by 36%, organic matter content increased by 22%, and the proportion of soil aggregates was significantly improved. Cotton plant height increased by 12 cm, the number of bolls per plant increased by 17%, and yield increased from 3200 kg / hm² to 3740 kg / hm², an increase of 17%. At the same time, all quality indicators and yields showed significant improvement.

[0053] Table 1:

[0054] Example 2 This embodiment provides an application of a compound biosynergist in severely saline-alkali cotton fields. Specifically, field verification was conducted in a severely saline-alkali cotton field in Korla, Xinjiang (average salt content of 12.5 g / kg in the 0–100 cm soil layer, pH 9.2, and organic matter 0.9%). In this embodiment, the compound biosynergist was formulated with a ratio of γ-PGA:HA:AOS:PP = 18:55:12:15. A solvent soaking method was used, with water (3% of the raw material) as the solvent, soaking at room temperature for 3 hours, followed by drying and pulverizing to 150 μm. The synergist was applied at a rate of 25 kg / hm², mixed with 200 kg / hm² of urea and 70 kg / hm² of potassium dihydrogen phosphate as base fertilizer. Irrigation was via drip irrigation under mulch, with a total quota of 5500 m³ / hm², and the drip irrigation cycle was monitored every 8–10 days using soil conductivity monitoring. After one growing season, soil salinity decreased by 40%, organic matter increased by 26%, bulk density decreased from 1.46 g / cm³ to 1.32 g / cm³, and porosity increased by 18%. Cotton survival rate increased by 15%, yield increased from 2600 kg / hm² to 3300 kg / hm², an increase of 27%, fiber length increased by 6.5%, and lint percentage increased by 4.2%. This shows that the method of the present invention can achieve significant stable yield and increased efficiency even in severely saline-alkali environments.

[0055] Comparative Example 1: Application of only conventional chemical fertilizers In a plot of land under the same conditions as in Example 1, without using the synergist of this invention, only urea (150 kg / hm²) and potassium dihydrogen phosphate (50 kg / hm²) were applied, and drip irrigation under mulch was used (quota 4500 m³ / hm²). The results showed that soil salinity decreased by only 12%, and organic matter content did not change significantly; cotton yield did not increase significantly (4.6%), and quality indicators did not improve significantly, indicating insufficient continuous field improvement effect.

[0056] Comparative Example 2: Application of humic acid alone This comparative example was conducted in a moderately saline-alkali cotton field with an average salt content of 8.0 g / kg. Humic acid was applied alone at 25 kg / hm², combined with drip irrigation under mulch (a fixed amount of 4500 m³ / hm²). After treatment, soil salinity decreased by 18%, organic matter increased by 12%, and yield increased by approximately 8%, while plant height and boll number showed limited improvement. Cotton fiber quality also saw limited improvement, with lint percentage increasing by less than 2%. The results indicate that while humic acid alone has some improving effect, it lacks a multi-component synergistic effect, and its overall effect is far lower than that of the method described in this invention.

[0057] Comparative Example 3: Application of traditional plaster amendment This comparative study involved applying 4 t / hm² of gypsum to a severely saline-alkali land with an average salt content of 12.0 g / kg, followed by flood irrigation (6000 m³ / hm²). Initially, the salinity decreased by 22%, but after 3 months, significant soil salinization occurred, electrical conductivity increased again, and soil aggregate structure showed no improvement. Cotton yield increased by only 9%, with no significant difference in quality indicators. This phenomenon indicates that while gypsum can leach salt in the short term, its long-term stability is insufficient, and its large dosage and high cost make it unsustainable.

[0058] Table 2

[0059] The technical effects of the examples and comparative cases in Table 2 demonstrate that the compound bio-synergist has a remarkably significant effect on improving saline-alkali cotton fields. This technology effectively reduces soil salinity and significantly improves water and fertilizer use efficiency. The ultimate effect is directly reflected in higher crop yields and improved quality, achieving yield increases of 17% and 27% in moderately and severely saline-alkali lands, respectively. It also significantly improves quality indicators such as fiber length and boll weight in cotton and other crops, demonstrating outstanding economic value.

[0060] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be understood that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A compound biological synergist, characterized in that, It is composed of polyglutamic acid, humic acid, brown alginic oligosaccharides and plant polyphenols.

2. The composite biosynergist according to claim 1, characterized in that, The proportions of each component by weight are as follows: polyglutamic acid, humic acid, alginic oligosaccharides and plant polyphenols = (15~25) : (40~60) : (5~15) : (10~20).

3. The method for preparing the composite biosynergist according to any one of claims 1-2, characterized in that, Polyglutamic acid, humic acid, fucoidan oligosaccharide and plant polyphenols are mixed by physical dry mixing, solvent soaking or mechanical stirring. The resulting mixture is dried at 40-50°C for 8-12 hours and then pulverized to a particle size of 50-200 μm to obtain the composite biosynergist.

4. The method according to claim 3, characterized in that, The physical dry mixing method specifically involves dry mixing polyglutamic acid, humic acid, fucoidan oligosaccharides, and plant polyphenols using a mixer with a speed of 15-60 rpm for 20-30 minutes.

5. The method according to claim 3, characterized in that, The solvent immersion method uses water or a non-toxic solvent as the solvent. The amount of the solvent used is 2% to 5% of the total weight of polyglutamic acid, humic acid, brown algae oligosaccharides and plant polyphenols. The immersion temperature is 15 to 40°C and the immersion time is 2 to 4 hours.

6. The method according to claim 3, characterized in that, The mechanical stirring method involves mixing polyglutamic acid, humic acid, fucoidan oligosaccharides, and plant polyphenols with water or a solvent at a stirring speed of 500-1500 rpm for 30-60 minutes.

7. The application of the compound biosynergist according to any one of claims 1-6 in saline-alkali land.

8. The application according to claim 7, characterized in that, The specific application steps are as follows: Step S1: Apply compound biological synergist to saline-alkali soil at a rate of 20-25 kg / hm². Step S2: Irrigation regulation is carried out using drip irrigation under mulch.

9. The application according to claim 8, characterized in that, In step S2, for moderately saline-alkali soil with an average salt content of 4-10 g / kg in the 0-100 cm soil layer, the irrigation quota is controlled between 4000 m³ / hm² and 5000 m³ / hm²; for severely saline-alkali soil with an average salt content of more than 10 g / kg in the 0-100 cm soil layer, the irrigation quota is controlled between 4500 m³ / hm² and 6000 m³ / hm².

10. An agricultural water and fertilizer management system, characterized in that, The system includes: a quantitative application unit for the compound biological synergist as described in any one of claims 1-8, a water source regulation and management unit, a soil monitoring and feedback unit, and an intelligent control unit.

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