An agricultural polymeric polypeptide composition, its preparation method and application

Abstract

The application discloses an agricultural polymeric polypeptide composition and a preparation method and application thereof, and belongs to the technical field of agricultural fertilizers.The polymeric polypeptide composition is prepared from the following raw materials in parts by weight: polyglutamic acid 5-20 parts, potassium fulvate 10-30 parts, chitosan oligosaccharide 3-10 parts, pollen polysaccharide 5-15 parts and functional adjuvant 5-15 parts.Through the polymerization and cooperation of multiple raw materials, the polymeric polypeptide composition can promote root growth, loosen soil, promote tillering, promote vegetative growth, improve seed setting rate and significantly increase yield.The preparation process is simple, the cost is low, the polymeric polypeptide composition is suitable for industrial production, is suitable for multiple crops and application scenes, is safe and environmentally friendly, has significant synergistic effect, and simultaneously solves the problems of moisture absorption and caking and Maillard reaction during the compounding of high-activity raw materials.

Description

Technical Field

[0001] This invention belongs to the technical field of agricultural fertilizers and plant growth regulators, specifically relating to a polymeric polypeptide composition with polyglutamic acid as the core, and particularly to a compound fertilizer that has the functions of promoting root growth, loosening soil, promoting tillering, promoting vegetative growth, increasing fruit setting rate, and increasing yield and quality, as well as its preparation and application. Background Technology

[0002] In existing technologies, rooting agents, soil conditioners, and biostimulants have limited functions and cannot simultaneously address issues such as weak root systems, soil compaction, poor nutrient absorption, and low fruit set. While theoretically, directly combining polyglutamic acid, potassium humate, chitosan oligosaccharides, and pollen polysaccharides could achieve functional complementarity, two major technical obstacles remain in practical production: First, potassium humate and chitosan oligosaccharides are highly hygroscopic, rapidly absorbing moisture, clumping, and even liquefying after simple mixing; second, the amino groups of chitosan oligosaccharides are prone to Maillard reactions with the carbonyl compounds in pollen polysaccharides and potassium humate during processing and storage, leading to browning and reduced activity in the products.

[0003] This invention aims to solve the aforementioned technological challenges through a unique formula design and a step-by-step coating and granulation process, while achieving synergistic effects of multiple active ingredients, and providing a compound fertilizer that combines strong rooting, soil loosening, tillering promotion, accelerated vegetative growth, improved fruit setting rate, and significant yield increase. Summary of the Invention

[0004] The purpose of this invention is to provide a polymeric polypeptide composition. Providing its preparation method and application is another objective of this invention. The composition of this invention uses polyglutamic acid as its core, polymerizing various nutrients and functional excipients to achieve comprehensive effects such as strong rooting, soil loosening, promoting tillering, accelerating vegetative growth, increasing fruit setting rate, and significantly increasing yield. It also solves the problems of potassium humate and chitosan oligosaccharides being highly hygroscopic, rapidly absorbing moisture, clumping, or even liquefying after simple mixing, and the Maillard reaction easily occurring between the amino groups of chitosan oligosaccharides and pollen polysaccharides, and the carbonyl compounds in potassium humate, leading to product browning and reduced activity during processing and storage.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A polymeric polypeptide composition comprising the following raw materials in parts by weight: 5-20 parts polyglutamic acid, 10-30 parts potassium humate, 3-10 parts chitosan oligosaccharide, 5-15 parts pollen polysaccharide, and 5-15 parts functional excipients.

[0006] Preferably, the polymeric polypeptide composition is composed of the following raw materials in parts by weight: 10 parts polyglutamic acid, 20 parts potassium humate, 6 parts chitosan oligosaccharide, 8 parts pollen polysaccharide, and 6 parts functional excipients.

[0007] Preferably, the functional excipient is composed of a buffer carrier, a dispersant, and a stabilizer, and the mass ratio of the buffer carrier, dispersant, and stabilizer is 5:3:2; the molecular weight of the polyglutamic acid is 500,000 to 3,000,000 Da. The reason for choosing a polyglutamic acid molecular weight of 500,000 to 3,000,000 Da in this invention is mainly because the aqueous solution of polyglutamic acid with a molecular weight of 500,000 to 3,000,000 Da has extremely high viscosity, exhibiting strong water absorption, water retention, and film-forming properties. Furthermore, the side chains of polyglutamic acid with this molecular weight have a large number of free carboxyl groups, and the ultra-long molecular chains form a more stable and massive three-dimensional network structure, strongly complexing metal ions such as calcium, magnesium, iron, and zinc, preventing them from being fixed by the soil and maintaining their absorbable state.

[0008] Preferably, the buffer carrier is one or a mixture of two or more of diatomaceous earth, attapulgite, humic acid powder, and light calcium carbonate.

[0009] More preferably, the buffer carrier is a mixture of diatomaceous earth and light calcium carbonate, with a mixing mass ratio of (2-4):1.

[0010] Preferably, the dispersant is one or a mixture of two or more of sodium lignosulfonate, alkyl polysaccharide (APG), and modified soybean lecithin.

[0011] Preferably, the stabilizer is one or a mixture of two or more of sodium citrate, citric acid-sodium citrate, and polyvinyl alcohol.

[0012] The present invention further discloses the application of the polymeric polypeptide composition in the preparation of polymeric polypeptide fertilizers.

[0013] Furthermore, the present invention discloses a method for preparing polymeric polypeptide fertilizer using the polymeric polypeptide composition, comprising the following steps: 1) Potassium humate is mixed with water to obtain a potassium humate aqueous solution with a concentration of 40-60%. This aqueous solution is used as a binder and mixed with a buffer carrier for granulation. After granulation, it is dried at 50-60℃ until the moisture content is ≤5% to obtain potassium humate carrier particles. This step locks the most hygroscopic potassium humate inside the particles and is wrapped by a porous carrier, thus completing the first layer of physical isolation. 2) Mix polyglutamic acid, chitosan oligosaccharide, pollen polysaccharide and other excipients with water, and stir at 25-30℃ for 15-30 minutes to obtain the coating solution; 3) The potassium humate carrier particles prepared in step 1) are fed into a fluidized bed. The functional active coating solution prepared in step 2) is uniformly sprayed onto the surface of the boiling potassium humate particles through a top spray or bottom spray system. The inlet air temperature is controlled at 45-50℃. While the coating solution is dried instantly, the particle temperature is ensured not to exceed 35℃ to minimize Maillard reaction and deactivation of heat-sensitive substances. This step can effectively form an active coating layer. The film-forming components achieve physical isolation between active substances, and the buffer system ensures chemical stability.

[0014] 4) After coating is completed, continue to circulate cold air until the temperature reaches room temperature, then discharge the material to obtain the finished product. Preferably, in step 2), the final pH of the coating solution is controlled at 5.5-6.0, and the solid content is 15-20%.

[0015] The product of this invention can be used in any of the following ways: For fertigation or drip irrigation: dilute 500-1000 times and apply once each during the seedling stage, tillering stage, and grain-filling stage, at a rate of 500-1000g per acre.

[0016] Foliar spray: Dilute 800-1500 times and spray during the tillering, booting, and grain-filling stages, using 300-500g per acre.

[0017] Base fertilizer or soil mixing: 1-2 kg per acre, simply mix with the soil.

[0018] The raw materials used in this invention are non-toxic, biodegradable, and residue-free, with wide applicability. It is suitable for various crops such as rice, wheat, corn, vegetables, and fruit trees, and can significantly enhance crop efficiency throughout its entire growth cycle. Seedling stage: Strongly promotes root growth, resulting in long taproots, numerous fibrous roots, and robust white root system; Growing period: Loosen the soil, break up compaction, increase aeration, and improve water and fertilizer retention capacity; promote tillering; Mid-to-late stage: Accelerates vegetative growth, resulting in dark green leaves and strong photosynthesis; improves seed setting rate, reduces empty grain rate, and increases thousand-grain weight; significantly increases yield.

[0019] The formulation of this invention consists of active ingredients and functional excipients. Polyglutamic acid, potassium humate, chitosan oligosaccharides, and pollen polysaccharides are all active ingredients. Among them, polyglutamic acid is the core component, primarily acting as a super-strong water-retention and chelating transport carrier. Its long-chain molecules can chelate trace elements such as calcium and magnesium in the soil, preventing their fixation and directly transporting nutrients to the rhizosphere. Simultaneously, its viscosity promotes the formation of soil aggregates. Potassium humate provides rapid soil improvement and carbon source stimulation. Its small molecular weight allows for rapid replenishment of active carbon in the soil, regulation of rhizosphere pH, stimulation of microbial activity, and enhancement of soil fertility. Chitosan oligosaccharides can directly stimulate root cell division. This invention promotes strong root development and acts as a plant immune stimulant, inducing systemic resistance in crops, enhancing their resilience, and reducing soil-borne diseases. Pollen polysaccharides replenish active polysaccharides, amino acids, and trace elements, promoting vegetative growth and increasing seed setting rate. Furthermore, the effective combination of these four components in a specific ratio allows for the formation of a long-lasting water-retaining film, locking in the carbon source and nutrients from potassium humate and preventing leaching, thus combining rapid and slow-acting soil improvement. Chitosan oligosaccharides strongly stimulate root development from the outside, while pollen polysaccharides provide comprehensive nutrition and hormone signals from within. This internal and external combination results in well-developed roots and vigorous tillering, laying the foundation for high yields.

[0020] The excipients selected in this invention are functional excipients. Buffer carriers such as diatomaceous earth and light calcium carbonate are mixed in a certain proportion. On the one hand, porous diatomaceous earth preferentially adsorbs environmental moisture, physically isolating hygroscopic raw materials; on the other hand, light calcium carbonate creates a slightly alkaline environment inside the particles, effectively inhibiting the Maillard reaction (which is prone to occur under acidic conditions), and also serves as a calcium source. Dispersants (such as alkyl polysaccharide glycosides, APG) aim to reduce the surface tension of the functional coating liquid, allowing it to spread instantly during fluidized bed spraying, forming a continuous and uniform active protective film. Stabilizers (such as citric acid-sodium citrate buffer pairs) stabilize the pH of the coating layer's microenvironment at 5.5-6.5, which is the most stable range for all active components. Furthermore, citric acid itself is a mild chelating agent, capable of complexing metal ions that may catalyze oxidation reactions.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The composition of this invention uses polyglutamic acid as the core and polymerizes various nutrients and functional additives to achieve comprehensive effects such as strong rooting, loosening soil, promoting tillering, accelerating vegetative growth, improving fruit setting rate, and significantly increasing yield. At the same time, this invention adopts a dry suspension-active coating granulation process, which fundamentally solves the problems of potassium humate and chitosan oligosaccharide being highly hygroscopic, rapidly absorbing moisture, clumping, or even liquefying after simple mixing, and the Maillard reaction easily occurring between the amino groups of chitosan oligosaccharide and pollen polysaccharides and the carbonyl compounds in potassium humate during processing and storage, leading to product browning and reduced activity. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments.

[0023] Example 1 This embodiment of a polymeric polypeptide composition comprises the following raw materials in parts by weight: 10 parts polyglutamic acid (molecular weight 1 million Da), 20 parts potassium humate, 6 parts chitosan oligosaccharide, 8 parts pollen polysaccharide, and 6 parts functional excipients. In this embodiment, the functional excipients consist of a buffer carrier, a dispersant, and a stabilizer, with a mass ratio of 5:3:2. The buffer carrier is a mixture of diatomaceous earth and light calcium carbonate, with a mass ratio of 3:1. The dispersant is an alkyl polysaccharide glycoside (APG), and the stabilizer is citric acid-sodium citrate.

[0024] A method for preparing polymeric polypeptide fertilizer using the polymeric polypeptide composition includes the following steps: 1) Potassium humate was mixed with water to obtain a 50% potassium humate aqueous solution. This aqueous solution was used as a binder and mixed with a buffer carrier for granulation. The mixture was then dried at 55°C until the moisture content was ≤5% to obtain potassium humate carrier particles. 2) Mix polyglutamic acid, chitosan oligosaccharide, pollen polysaccharide, and other excipients with water, and stir at 25°C for 20 minutes to obtain a coating solution; control the final pH of the coating solution at 5.5 and the solid content at 18%; 3) The potassium humate carrier particles prepared in step 1) are put into a fluidized bed. The functional active coating solution prepared in step 2) is uniformly sprayed onto the surface of the boiling potassium humate particles through a top spray or bottom spray system. The air inlet temperature is controlled at 48°C. While the coating solution is dried instantly, the particle temperature is ensured not to exceed 35°C to prevent Maillard reaction and deactivation of heat-sensitive substances to the greatest extent. 4) After coating is completed, continue to circulate cold air until the temperature reaches room temperature, then discharge the material to obtain the finished product. Example 2 This embodiment presents a polymeric polypeptide composition comprising the following raw materials in parts by weight: 5 parts polyglutamic acid (molecular weight 1 million Da), 10 parts potassium humate, 3 parts chitosan oligosaccharide, 5 parts pollen polysaccharide, and 5 parts functional excipients. The functional excipients consist of a buffer carrier, a dispersant, and a stabilizer, with a mass ratio of 5:3:2. The buffer carrier is a mixture of diatomaceous earth and light calcium carbonate, with a mass ratio of 2:1. The dispersant is an alkyl polysaccharide glycoside (APG), and the stabilizer is citric acid-sodium citrate.

[0025] A method for preparing polymeric polypeptide fertilizer using the polymeric polypeptide composition includes the following steps: 1) Potassium humate was mixed with water to obtain a 40% potassium humate aqueous solution. This aqueous solution was used as a binder and mixed with a buffer carrier for granulation. The mixture was then dried at 50°C until the moisture content was ≤5% to obtain potassium humate carrier particles. 2) Mix polyglutamic acid, chitosan oligosaccharide, pollen polysaccharide, and other excipients with water, and stir at 25°C for 30 minutes to obtain a coating solution; control the final pH of the coating solution at 6.0 and the solid content at 15%; 3) The potassium humate carrier particles prepared in step 1) are put into a fluidized bed. The functional active coating solution prepared in step 2) is uniformly sprayed onto the surface of the boiling potassium humate particles through a top spray or bottom spray system. The air inlet temperature is controlled at 45°C. While the coating solution is dried instantly, the particle temperature is ensured not to exceed 35°C to prevent Maillard reaction and deactivation of heat-sensitive substances to the greatest extent. 4) After coating is completed, continue to circulate cold air until the temperature reaches room temperature, then discharge the material to obtain the finished product.

[0026] Example 3 This embodiment provides a polymeric polypeptide composition comprising the following raw materials in parts by weight: 20 parts polyglutamic acid (molecular weight 1 million Da), 30 parts potassium humate, 10 parts chitosan oligosaccharide, 15 parts pollen polysaccharide, and 15 parts functional excipients. The functional excipients consist of a buffer carrier, a dispersant, and a stabilizer, with a mass ratio of 5:3:2. The buffer carrier is a mixture of diatomaceous earth and light calcium carbonate, with a mass ratio of 4:1. The dispersant is an alkyl polysaccharide glycoside (APG), and the stabilizer is citric acid-sodium citrate.

[0027] A method for preparing polymeric polypeptide fertilizer using the polymeric polypeptide composition includes the following steps: 1) Potassium humate was mixed with water to obtain a 60% potassium humate aqueous solution. This aqueous solution was used as a binder and mixed with a buffer carrier for granulation. The mixture was then dried at 60°C until the moisture content was ≤5% to obtain potassium humate carrier particles. 2) Mix polyglutamic acid, chitosan oligosaccharide, pollen polysaccharide, and other excipients with water, and stir at 30°C for 15 minutes to obtain a coating solution; control the final pH of the coating solution at 5.5 and the solid content at 20%; 3) The potassium humate carrier particles prepared in step 1) are put into a fluidized bed. The functional active coating solution prepared in step 2) is uniformly sprayed onto the surface of the boiling potassium humate particles through a top spray or bottom spray system. The air inlet temperature is controlled at 50°C. While the coating solution is dried instantly, the particle temperature is ensured not to exceed 35°C to prevent Maillard reaction and deactivation of heat-sensitive substances to the greatest extent. 4) After coating is completed, continue to circulate cold air until the temperature reaches room temperature, then discharge the material to obtain the finished product.

[0028] In other embodiments, the buffer carrier is one or a mixture of two or more of diatomaceous earth, attapulgite, humic acid powder and light calcium carbonate; the dispersant is one or a mixture of two or more of sodium lignosulfonate, alkyl polysaccharide (APG) and modified soybean lecithin; and the stabilizer is one or a mixture of two or more of sodium citrate, citric acid-sodium citrate and polyvinyl alcohol, all of which can achieve the effects of the present invention.

[0029] Effect Test 1 To verify the effectiveness of this invention against moisture absorption, clumping, and Maillard reactions, the comparative experiment was designed as follows: Experimental sample preparation: Taking Example 1 as an example, Control 1 and Control 2 were prepared respectively. Control 1 was a simple mixing group: its formula was the same as that of Example 1, except that Control 1 used direct physical mixing and did not add functional excipients or granulation. Control 2 was a conventional granulation group: its formula was the same as that of Control 1, without adding functional excipients, and was granulated using conventional disc granulation (using water as a binder and drying with hot air at 80°C).

[0030] Moisture absorption and clumping test method: Take 50g of each sample from Example 1, Control 1, and Control 2, spread them evenly in an open petri dish, and place them in a constant temperature and humidity chamber at 30℃ and 75% relative humidity. Observe the appearance and measure the moisture content after 24h and 72h, respectively. The test results are shown in Table 1.

[0031] Maillard (anti-browning) efficacy test method: Take 50g of each sample from Example 1, Control 1, and Control 2, seal them in a package, and place them in an oven at 50℃ for accelerated storage. After 7 days, take them out, observe the color change, and determine the retention rate of effective chitosan oligosaccharide content. The test results are shown in Table 2.

[0032] Table 1. Test results of moisture absorption and clumping of the present invention, control 1, and control 2. Table 2. Anti-browning test results of the present invention, control 1, and control 2. As shown in Table 1, the simple mixing in Control 1 resulted in severe moisture absorption, rendering it completely ineffective and unusable. Conventional granulation in Control 2 showed improvement, but failed to eliminate the moisture absorption problem. This invention (Example 1) employs stepwise coating and carrier isolation technology, successfully solving the problem of moisture absorption and clumping.

[0033] As shown in Table 2, Control 1 underwent a severe Maillard reaction, resulting in significant loss of active substances. While the high-temperature drying of Control 2 promoted the reaction, browning and activity loss were still significant. The low-temperature process and microenvironment pH buffer system of this invention successfully inhibited the reaction, preserving the activity intact.

[0034] Effect Experiment 2: Application Effect Experiment Experimental Design: Test crop: Rice (representative grain crop). The experiment included the following four treatments, with three replicates. Treatment 1: Blank control (CK), conventional fertilization, no experimental product applied; Treatment 2: Commercially available rooting agent, applied at the recommended dosage; Treatment 3: Commercially available humic acid soil conditioner, applied at the recommended dosage; Treatment 4: Product of Example 1 of this invention, diluted 800 times, sprayed on the leaves once each during the tillering and booting stages, at a dosage of 500g / mu.

[0035] The comparison of application effects is shown in Table 3: Table 3 Comparison of Application Effects As shown in Table 3, compared to treatments 1-3, the formulation of this invention ensures robust root growth, loosens the soil, and increases the number of effective tillers, seed setting rate, and final yield. The mechanism is as follows: chitosan oligosaccharides and pollen polysaccharides synergistically promote strong root development; polyglutamic acid transports nutrients, ensuring a well-developed and robust root system; and the water-retention and binding effects of polyglutamic acid, combined with the carbon supply from potassium humate, significantly promote aggregate structure and loosen the soil. A strong root system and loose soil provide physical space and sufficient nutrients for tillering. Pollen polysaccharides provide hormonal signals, directly supplying the nutrients and endogenous hormones needed for pollen tube germination during the heading-flowering stage, significantly increasing the seed setting rate. Therefore, the formulation of this invention works synergistically throughout the entire growth cycle—from root development to soil improvement, nutrition, and yield increase—successfully transforming the advantages of the early and mid-stages into a significant increase in final yield.

[0036] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A polymeric polypeptide composition, characterized in that, It is composed of the following raw materials in parts by weight: 5-20 parts polyglutamic acid, 10-30 parts potassium humate, 3-10 parts chitosan oligosaccharide, 5-15 parts pollen polysaccharide, and 5-15 parts excipients.

2. The polymeric polypeptide composition according to claim 1, characterized in that, It is composed of the following raw materials in parts by weight: 10 parts polyglutamic acid, 20 parts potassium humate, 6 parts chitosan oligosaccharide, 8 parts pollen polysaccharide, and 6 parts functional excipients.

3. The polymeric polypeptide composition according to claim 1, characterized in that, The functional excipient is composed of a buffer carrier, a dispersant, and a stabilizer, and the ratio of the three components is 5:3:2; the molecular weight of the polyglutamic acid is 500,000 to 3,000,000.

4. The polymeric polypeptide composition according to claim 3, characterized in that, The buffer carrier is one or a mixture of two or more of the following: diatomaceous earth, attapulgite, humic acid powder, and light calcium carbonate.

5. The polymeric polypeptide composition according to claim 4, characterized in that, The buffer carrier is a mixture of diatomaceous earth and light calcium carbonate, with a weight mixing ratio of (2-4):

1.

6. The polymeric polypeptide composition according to claim 3, characterized in that, The dispersant is one or a mixture of two or more of sodium lignosulfonate, alkyl polysaccharide (APG), and modified soybean lecithin.

7. The polymeric polypeptide composition according to claim 3, characterized in that, The stabilizer is one or a mixture of two or more of sodium citrate, citric acid-sodium citrate, and polyvinyl alcohol.

8. The use of the polymeric polypeptide composition according to any one of claims 1-7 in the preparation of polymeric polypeptide fertilizer.

9. A method for preparing polymeric polypeptide fertilizer using the polymeric polypeptide composition according to any one of claims 1-7, characterized in that, Includes the following steps: 1) Potassium humate is mixed with water to obtain a potassium humate aqueous solution with a concentration of 40-60%. This aqueous solution is used as a binder to mix with a buffer carrier and granulate. After granulation, it is dried at 50-60℃ until the moisture content is ≤5% to obtain potassium humate carrier particles. 2) Mix polyglutamic acid, chitosan oligosaccharide, pollen polysaccharide and other excipients with water, and stir at 25-30℃ for 15-30 minutes to obtain the coating solution; 3) The potassium humate carrier particles prepared in step 1) are put into a fluidized bed. The functional active coating solution prepared in step 2) is uniformly sprayed onto the surface of the boiling potassium humate particles through a top spray or bottom spray system. The air inlet temperature is controlled at 45-50℃. While the coating solution is dried instantly, the particle temperature is ensured not to exceed 35℃. 4) After coating is completed, continue to circulate cold air until the temperature reaches room temperature, then discharge the material to obtain the finished product.

10. The method for preparing polymeric polypeptide fertilizer using a polymeric polypeptide composition according to claim 9, characterized in that, In step 2), the final pH of the coating solution is controlled at 5.5-6.0, and the solid content is 15-20%.

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