A kind of humic acid water-soluble fertilizer containing bacterial agent and its production process

Abstract

The present invention discloses a humic acid water-soluble fertilizer containing a bacterial agent and a production process thereof. The humic acid water-soluble fertilizer comprises humic acid, bacterial strains and a binder; the production process comprises the steps of grading humic acid, coating bacterial strains, preparing potassium humate, preparing a binder water agent, preparing fertilizer granules and drying fertilizer granules. Aiming at the characteristics of the existing fulvic acid and its salts being easy to crystallize and harden after being dissolved in water, the invention proposes grading potassium fulvic acid, and at the same time, utilizing the alkali catalytic effect of potassium fulvic acid on the hydrolysis of polyacrylamide and the flocculation effect of polyacrylamide on the crystallization of potassium fulvic acid, mixing potassium fulvic acid with a larger molecular weight, being difficult to dissolve and being easy to crystallize with polyacrylamide, forming a multi-shell particle structure of polyacrylamide and potassium fulvic acid coating the bacterial agent. The formed particles have high water retention, can ensure the long-term effectiveness of potassium fertilizer and bacterial agent, have a slow-release effect of fertilizer effect, and are not easy to stick to roots and have no adverse effects on soil structure.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer production, and in particular to a humic acid water-soluble fertilizer containing a bacterial agent and a production process thereof. Background Art

[0002] With the refinement of agricultural soil science research, traditional inorganic fertilizers are very likely to change soil structure after application, causing soil compaction, which seriously affects agricultural production. Therefore, the development of multi-effect organic fertilizers and microbial fertilizers is becoming more and more important. Organic fertilizers are represented by humic acid, and microbial fertilizers are represented by various nitrogen-fixing and phosphorus-fixing microorganisms.

[0003] In addition, the new fertilizers have good compatibility with inorganic fertilizers. For example, humic acid fertilizers made by combining with nitrogen, phosphorus, potassium and other elements have the functions of increasing fertilizer efficiency, improving soil, stimulating crop growth, and improving the quality of agricultural products. For example, humic acid magnesium, humic acid zinc, and humic acid urea iron have good effects in supplementing soil magnesium deficiency, corn zinc deficiency, and fruit tree iron deficiency, respectively. Another example is humic acid microbial coated compound fertilizer, which overcomes the incompatibility problem between microorganisms and humic acid by coating the outer surface of the bacteria, while achieving a slow-release effect.

[0004] However, humic acid has poor solubility. Even fulvic acid and fulvic acid salts, which have better solubility, still have the defects of high pH value, easy crystallization and easy growth of crystals and agglomeration. When applied to the soil, it is easy to cause the soil pH value or salinity to be too high, thereby changing the soil structure. Therefore, the existing technology still needs to grade fulvic acid before use.

[0005] In addition, the humic acid or bacteria in the powder form can easily produce the side effect of sticking to the roots and wrapping the root bark when applied, creating the risk of insufficient soil permeability.

[0006] Based on the above analysis, the present invention attempts to propose a granular water-soluble fertilizer that integrates potassium humate and bacteria, and attempts to wrap and protect the bacteria, and grade the potassium humate to promote the uniformity of the water solubility of the particles to avoid affecting the soil structure. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a humic acid water-soluble fertilizer containing a bacterial agent and a production process thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A humic acid water-soluble fertilizer containing a bacterial agent, comprising the following components by weight: 85-90 parts of humic acid, 3-7 parts of bacterial strains, 1-3 parts of a binder, and the rest being water;

[0010] Humic acid is divided into multiple parts. The adhesive, part of humic acid and water are mixed to form an adhesive water agent. Part of humic acid and all bacteria are mixed to form a particle core. The particle core is wrapped with a first layer of adhesive water agent. The first layer of adhesive water agent is adhered to the first layer of humic acid adhesion. The first layer of humic acid adhesion is wrapped with a second layer of adhesive water agent. The second layer of adhesive water agent is adhered to the second layer of humic acid adhesion, thus forming a multi-layer wrapped particle structure.

[0011] By improving the granulation process, a multi-layer wrapped and adhered bacterial strain and humic acid mixed structure is achieved, and a new type of fertilizer granule with long fertilizer effect and strong water retention is prepared.

[0012] Preferably, the humic acid is mineral-derived potassium humate, which has good water solubility.

[0013] Preferably, the bacterial species is an alkaline-resistant Bacillus, which includes at least one of Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, Bacillus azotobacter, Bacillus sphaericus or Bacillus laterosporus. Bacillus has biological activities such as phosphate solubilization, potassium solubilization and nitrogen fixation, which is beneficial to increasing crop yields. In addition, Bacillus has good stress resistance and is widely used in the production of biofertilizers.

[0014] Preferably, the adhesive is partially hydrolyzed polyacrylamide with a hydrolysis degree of about 20-25%, obtained by alkaline-catalyzed hydrolysis of polyacrylamide with a concentration of 5-10%, and the adhesive aqueous agent contains hydrolyzed polyacrylamide and potassium fulvic acid.

[0015] According to the mixing requirements of bacterial strains and humic acid, in order to better encapsulate the bacterial agent and maintain the microbial growth conditions for a long time after fertilization, the present invention proposes a production process of humic acid water-soluble fertilizer containing bacterial agent, comprising the following steps:

[0016] 1. Make adhesive water:

[0017] 1) Weigh the adhesive and weigh 5 times the mass of pure water as the adhesive;

[0018] 2) Pour pure water into the small reactor, start the machine, add the adhesive during the stirring process, and mix thoroughly;

[0019] 3) The mixed solution needs to be left for 2 hours to allow it to react fully;

[0020] 4) After 2 hours, restart the reactor, stir it thoroughly, and introduce it into the storage barrel for standby use;

[0021] 2. Manufacturing particles:

[0022] 1) Weigh a sufficient amount of mineral source potassium humate tablets and introduce them into the crusher through a conveyor belt, start the machine, adjust the crushing time, and crush them into a powder of 100-120 mesh;

[0023] 2) taking one third of the total amount of potassium humate powder and putting it into a disc granulator;

[0024] 3) taking all the dormant strains and putting them into the disc granulator, adjusting the angle and speed of the machine to granulate;

[0025] 4) Spray the adhesive water onto the disc surface of the disc granulator, and complete the first granulation through continuous rotation, with a particle size of 1.5-2.0 mm;

[0026] 5) During the rotation of the disc, the remaining potassium humate is put into the feed port of the disc granulator for secondary coating and granulation;

[0027] 6) Re-adjust the angle of the disc, increase its angle, spray the adhesive water on its surface again, and complete the granulation, with a particle size of 4-4.5 mm;

[0028] 7) The formed particles are introduced into a vibrating screen with a mesh size of 60, and particles within the qualified units are screened by vibration;

[0029] 8) The particles are introduced into a dryer for secondary drying, and the temperature is maintained at 50°C for low temperature drying;

[0030] 9) Take some particles and put them into the moisture detector to detect the moisture content of the particles. When the moisture content is ≤10%, the particles are dried and introduced into the material packaging machine for packaging as required;

[0031] 10) Storage.

[0032] Preferably, the adhesive contains polyacrylamide and potassium humate, and the mass ratio of polyacrylamide to potassium humate is 1.5-2:1. The alkaline potassium humate accelerates the hydrolysis of polyacrylamide to produce hydrolyzed polyacrylamide, thereby improving adhesion and water absorption.

[0033] On the basis of the above production process, according to the situation of applying the formed particles in the soil during actual application, the solubility of potassium humate in various parts of the particles is inconsistent, and it is easy to form larger potassium humate crystal particles during the water dissolution process, resulting in higher salinity and alkalinity of the soil in a long time, making the soil caking, drought-resistant, and insufficiently improving water retention. Therefore, the present invention also proposes an improved production process of humic acid water-soluble fertilizer containing bacterial agents, comprising the following steps:

[0034] S1. Classification of humic acid:

[0035] Adding mineral fulvic acid into water and fully dissolving it to obtain a fulvic acid aqueous solution, adding a 5-10% polyacrylamide aqueous solution, the mass ratio of the fulvic acid aqueous solution to the polyacrylamide aqueous solution being 1:0.06-0.08, and after flocculation and sedimentation, obtaining a yellow-grey flocculated precipitate A and a clarified solution B;

[0036] Although mineral-derived fulvic acid is more water-soluble than humic acid, it is still easy to precipitate when it comes into contact with hard water, causing uneven fertilizer or clogging of the spraying pipeline. Therefore, the present invention uses a polyacrylamide flocculant to perform primary flocculation treatment on the easily precipitated components therein to form a yellow-gray flocculated precipitate A, in which a part of the fulvic acid that is easily soluble in water is also wrapped in the gel cavity; the fulvic acid in the clear solution B has a higher solubility and is difficult to precipitate, and the clear solution B still contains polyacrylamide;

[0037] S2. Bacteria packaging:

[0038] A sufficient amount of potassium oxide is added to the clarified solution B, and the solution is fully reacted for 30 minutes until the pH value of the system is 12-13. The solution is stirred and heated to 105-110°C to produce a viscous solution C with a viscosity of 3000-5000 cPs. The viscous solution C is cooled to room temperature, and the prepared dormant bacteria are added. The solution is stirred to produce needle-like crystals on the surface of the bacteria. The bacteria with yellow-white flocculent crystals on the surface are aged to obtain a viscous solution D with a viscosity of 6000-8000 cPs. The rest is vacuum dried at 50°C to obtain a semi-dormant bacteria E.

[0039] The semi-dormant strain E contains potassium fulvic acid crystals that are easy to crystallize. After being soaked in alkaline solution and dried at low temperature, the spore sheath of the dormant strain is initially activated.

[0040] S3. Preparation of potassium humate:

[0041] The viscous liquid D was vacuum dried at 50°C to obtain potassium humate powder F;

[0042] Under the alkaline catalysis of potassium oxide, the hydrolysis of polyacrylamide is accelerated to obtain hydrolyzed polyacrylamide in which part of the amide groups are hydrolyzed into carboxylates, thereby improving the water absorption capacity and flocculation capacity. Under the action of the seed crystals of the dormant bacteria, the further precipitation of potassium humate is promoted, thereby further classifying the potassium humate. It is found that the molecular weight of potassium humate powder F is less than 300 (in terms of number average molecular weight), the molecular weight of potassium humate of semi-dormant bacteria E is 300-500 (in terms of number average molecular weight), and the molecular weight of humic acid of the adhesive water agent G is greater than 500 (in terms of number average molecular weight);

[0043] S4. Preparation of adhesive water:

[0044] Mix equal masses of flocculation precipitate A and potassium oxide, add water 3-4 times the mass of the solid (i.e., flocculation precipitate A and potassium oxide), fully stir and react in a 40-50° C. water bath for 2 hours to obtain a bonding agent G with a viscosity of 1000-1500 cPs, wherein the bonding agent G contains completely dissolved potassium humate and hydrolyzed polyacrylamide in which part of the amide groups are hydrolyzed to carboxylates;

[0045] Among them, the hydrolysis degree of hydrolyzed polyacrylamide is difficult to measure, and the carboxylate and amide groups both show similar carbonyl infrared characteristic peaks, and can only be roughly calculated according to the following method: binder water G or viscous liquid C, rotary evaporation to obtain colloid, by eluting the colloid for 3-5, eluting potassium humate, the eluted colloid is re-prepared into an aqueous solution with a concentration of 3-5%, and titrated with 0.1 mol / L dilute hydrochloric acid aqueous solution to pH 7.0±0.3, the carboxylate content is calculated based on the amount of hydrochloric acid used, and the preliminary statistical hydrolysis degree is about 20-25%.

[0046] S5. Preparation of fertilizer granules:

[0047] Put the semi-dormant strain E into the disc granulator, adjust the machine angle and speed, and granulate;

[0048] Spray the adhesive water G on the disc surface of the disc granulator, and complete the first granulation through continuous rotation, with a particle size of 1.5-2.0mm;

[0049] During the rotation of the disc, potassium humate powder F is put into the feeding port of the disc granulator for secondary coating and granulation;

[0050] The angle of the disc is readjusted to increase it, and the bonding agent G is sprayed on its surface again to complete granulation, with a particle size of 4-4.5 mm; the bonding agent G on the outer layer can also bond the unbonded powder and small particles in the disc, including the remaining semi-dormant bacteria E or potassium humate powder F, so that the particle forming qualified rate is as high as more than 95%, thereby improving production efficiency;

[0051] S6. Drying of fertilizer granules:

[0052] The S5 formed particles are introduced into a vibrating screen with a mesh size of 60, and particles within the qualified units are screened by vibration;

[0053] The granules are introduced into the dryer for secondary drying, and the temperature is maintained at 50°C for low temperature drying;

[0054] Take some particles and put them into the moisture detector to test the moisture content of the particles. When the moisture content is ≤10%, the drying is completed and the formed particles are obtained. They are introduced into the material filling machine, packed according to the requirements and put into storage.

[0055] Preferably, in the first particle formation in S5, the semi-dormant bacteria E may be mixed with chopped straw powder having substantially the same particle size, and the mass ratio of the chopped straw powder to the semi-dormant bacteria E is 0-0.2:1, so as to increase the spacing between the bacteria and make the inner core of the formed particles more fluffy;

[0056] Preferably, in the secondary encapsulation granulation in S5, potassium humate powder F may be mixed with inorganic fertilizer powder having substantially the same particle size, wherein the inorganic fertilizer powder includes phosphate fertilizer or nitrogen fertilizer, and the mass ratio of the inorganic fertilizer powder to potassium humate powder F is 0-0.3:1, so as to improve the fertilizer efficiency and have a slow release effect on the inorganic fertilizer;

[0057] Preferably, the adhesive water agent G is also mixed with an inorganic binder, such as bentonite or attapulgite, and the inorganic binder accounts for no more than 20% of the total mass of the adhesive water agent G, so as to enhance the bonding performance, improve the strength of the particles, and avoid crushing.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. The present invention improves the existing granulation process, encapsulates the bacteria with potassium humate, and uses two particle enlargement processes of a bonding water agent after encapsulation to achieve multiple protections for the bacteria. The obtained fertilizer particles are a multi-layer core-shell structure with strong structural stability and high water retention.

[0060] 2. In view of the fact that existing humic acid and its salts are easy to crystallize and harden after being dissolved in water, the present invention proposes to grade potassium humate, and mix potassium humate with polyacrylamide, which has a larger molecular weight, is more difficult to dissolve and is easy to crystallize, and forms a more solid double-layer shell structure through granulation and packaging, thereby further improving the structural stability of the formed particles.

[0061] 3. The present invention simultaneously utilizes the alkali catalytic effect of potassium humate on the hydrolysis of polyacrylamide and the flocculation effect of polyacrylamide on the crystallization of potassium humate, improves the water retention rate and flocculation ability of polyacrylamide through hydrolysis, and achieves the purpose of potassium humate classification through flocculation.

[0062] 4. The present invention realizes the particle structure of potassium humate wrapped bacterial agent through polyacrylamide auxiliary bonding. The molded particles have high water retention, can ensure the long-term effectiveness of potassium fertilizer and bacterial agent, have a slow-release effect of fertilizer effect, are not easy to stick to roots, and have no adverse effect on soil structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a flow chart of a production process of a humic acid water-soluble fertilizer containing a bacterial agent proposed by the present invention;

[0064] Figure 2 This is a simplified structural diagram of a humic acid water-soluble fertilizer containing a bacterial agent proposed by the present invention. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0066] Embodiment Group A:

[0067] The present invention provides a production process of a humic acid water-soluble fertilizer containing a bacterial agent, comprising the following steps:

[0068] 1. Make adhesive water:

[0069] 1) Weighing an adhesive, the adhesive contains polyacrylamide and potassium humate, the mass ratio of polyacrylamide to potassium humate is 1.5-2:1, and weighing pure water 5 times the mass of the adhesive;

[0070] 2) Pour pure water into the small reactor, start the machine, add the adhesive during the stirring process, and mix thoroughly;

[0071] 3) The mixed solution needs to be left for 2 hours to allow it to react fully;

[0072] 4) After 2 hours, restart the reactor, stir it thoroughly, and introduce it into the storage barrel for standby use;

[0073] 2. Manufacturing particles:

[0074] 1) Weigh a sufficient amount of mineral source potassium humate tablets and introduce them into the crusher through a conveyor belt, start the machine, adjust the crushing time, and crush them into a powder of 100-120 mesh;

[0075] 2) taking one third of the total amount of potassium humate powder and putting it into a disc granulator;

[0076] 3) taking all the dormant strains and putting them into the disc granulator, adjusting the angle and speed of the machine to granulate;

[0077] 4) Spray the adhesive water onto the disc surface of the disc granulator, and complete the first granulation through continuous rotation, with a particle size of 1.5-2.0 mm;

[0078] 5) During the rotation of the disc, the remaining potassium humate is put into the feed port of the disc granulator for secondary coating and granulation;

[0079] 6) Re-adjust the angle of the disc, increase its angle, spray the adhesive water on its surface again, and complete the granulation, with a particle size of 4-4.5 mm;

[0080] 7) The formed particles are introduced into a vibrating screen with a mesh size of 60, and particles within the qualified units are screened by vibration;

[0081] 8) The particles are introduced into a dryer for secondary drying, and the temperature is maintained at 50°C for low temperature drying;

[0082] 9) Take some particles and put them into the moisture detector to detect the moisture content of the particles. When the moisture content is ≤10%, the particles are dried and introduced into the material packaging machine for packaging as required;

[0083] 10) Storage.

[0084] The usage of the obtained humic acid water-soluble fertilizer containing bacterial agent is shown in Table 1:

[0085] Table 1 Amount of each component in Example A

[0086]

[0087] Note: The water solubility of potassium humate decreases from grade I to grade III. Grade I has no obvious precipitation in hard water, grade II has obvious crystallization in hard water, and grade III has obvious precipitation and turbidity in hard water.

[0088] Embodiment Group B:

[0089] On the basis of Example 3, according to the situation of applying the formed particles in the soil during actual application, the solubility of potassium humate in various parts of the particles is inconsistent, and larger potassium humate crystal particles are easily formed during the water dissolution process, resulting in higher salinity and alkalinity of the soil in a long time, making the soil caking, drought-resistant, and insufficiently improving water retention. Therefore, the present invention also proposes an improved production process of humic acid water-soluble fertilizer containing bacterial agents, comprising the following steps:

[0090] S1. Classification of humic acid:

[0091] Adding mineral fulvic acid into water and fully dissolving it to obtain a fulvic acid aqueous solution, adding a 5-10% polyacrylamide aqueous solution, the mass ratio of the fulvic acid aqueous solution to the polyacrylamide aqueous solution being 1:0.06-0.08, and after flocculation and sedimentation, obtaining a yellow-grey flocculated precipitate A and a clarified solution B;

[0092] Although mineral-derived fulvic acid is more water-soluble than humic acid, it is still easy to precipitate when it comes into contact with hard water, causing uneven fertilizer or clogging of the spraying pipeline. Therefore, the present invention uses a polyacrylamide flocculant to perform primary flocculation treatment on the easily precipitated components therein to form a yellow-gray flocculated precipitate A, in which a part of the fulvic acid that is easily soluble in water is also wrapped in the gel cavity; the fulvic acid in the clear solution B has a higher solubility and is difficult to precipitate, and the clear solution B still contains polyacrylamide;

[0093] S2. Bacteria packaging:

[0094] A sufficient amount of potassium oxide is added to the clarified solution B, and the solution is fully reacted for 30 minutes until the pH value of the system is 12-13. The solution is stirred and heated to 105-110°C to produce a viscous solution C with a viscosity of 3000-5000 cPs. The viscous solution C is cooled to room temperature, and the prepared dormant bacteria are added. The solution is stirred to produce needle-like crystals on the surface of the bacteria. The bacteria with yellow-white flocculent crystals on the surface are aged to obtain a viscous solution D with a viscosity of 6000-8000 cPs. The rest is vacuum dried at 50°C to obtain a semi-dormant bacteria E.

[0095] The semi-dormant strain E contains potassium fulvic acid crystals that are easy to crystallize. After being soaked in alkaline solution and dried at low temperature, the spore sheath of the dormant strain is initially activated.

[0096] S3. Preparation of potassium humate:

[0097] The viscous liquid D was vacuum dried at 50°C to obtain potassium humate powder F;

[0098] Under the alkaline catalysis of potassium oxide, the hydrolysis of polyacrylamide is accelerated to obtain hydrolyzed polyacrylamide in which part of the amide groups are hydrolyzed into carboxylates, thereby improving the water absorption capacity and flocculation capacity. Under the action of the seed crystals of the dormant bacteria, the further precipitation of potassium humate is promoted, thereby further classifying the potassium humate. It is found that the molecular weight of potassium humate powder F is less than 300 (in terms of number average molecular weight), the molecular weight of potassium humate of semi-dormant bacteria E is 300-500 (in terms of number average molecular weight), and the molecular weight of humic acid of the adhesive water agent G is greater than 500 (in terms of number average molecular weight);

[0099] S4. Preparation of adhesive water:

[0100] Mix equal masses of flocculation precipitate A and potassium oxide, add water 3-4 times the mass of the solid, stir and react in a water bath at 40-50°C for 2 hours, and obtain a binder G with a viscosity of 1000-1500 cPs. The binder G contains completely dissolved potassium humate and hydrolyzed polyacrylamide in which part of the amide groups are hydrolyzed to carboxylates.

[0101] Among them, the hydrolysis degree of hydrolyzed polyacrylamide is difficult to measure, and the carboxylate and amide groups both show similar carbonyl infrared characteristic peaks, and can only be roughly calculated according to the following method: binder water G or viscous liquid C, rotary evaporation to obtain colloid, elute the colloid for 3-5, elute potassium humate, and re-form the eluted colloid into an aqueous solution with a concentration of 3-5%, and titrate it with 0.1 mol / L dilute hydrochloric acid aqueous solution to pH 7.0±0.3, calculate the carboxylate content based on the amount of hydrochloric acid used, and the preliminary statistical hydrolysis degree is about 20-25%.

[0102] S5. Preparation of fertilizer granules:

[0103] Put the semi-dormant strain E into the disc granulator, adjust the machine angle and speed, and granulate;

[0104] Spray the adhesive water G on the disc surface of the disc granulator, and complete the first granulation through continuous rotation, with a particle size of 1.5-2.0mm;

[0105] During the rotation of the disc, potassium humate powder F is put into the feeding port of the disc granulator for secondary coating and granulation;

[0106] The angle of the disc is readjusted to increase it, and the bonding agent G is sprayed on its surface again to complete granulation, with a particle size of 4-4.5 mm; the bonding agent G on the outer layer can also bond the unbonded powder and small particles in the disc, including the remaining semi-dormant bacteria E or potassium humate powder F, so that the particle forming qualified rate is as high as more than 95%, thereby improving production efficiency;

[0107] S6. Drying of fertilizer granules:

[0108] The S5 formed particles are introduced into a vibrating screen with a mesh size of 60, and particles within the qualified units are screened by vibration;

[0109] The granules are introduced into the dryer for secondary drying, and the temperature is maintained at 50°C for low temperature drying;

[0110] Take some particles and put them into the moisture detector to test the moisture content of the particles. When the moisture content is ≤10%, the drying is completed and the formed particles are obtained. They are introduced into the material filling machine, packed according to the requirements and put into storage.

[0111] According to the formula of Example 3, the raw materials of Example 4 are: 9 kg of potassium fulvic acid grade I, 0.3 kg of polyacrylamide, and 0.3 kg of Bacillus subtilis. The contents of the specific intermediate products and formed particles are shown in Table 2:

[0112] Table 2 Product amount of formed particles after classification

[0113]

[0114] The moisture content in the formed particles is 4.5%, and the yield can be estimated to be 9.15 / (9+0.3+0.3)=95.31%.

[0115] Grade II water-soluble fulvic acid is mixed with bacteria to form a particle inner core, the particle inner core is wrapped with a first layer of binding water agent, the potassium fulvic acid in the binding water agent is grade III water-soluble, the first layer of binding water agent is adhered to grade I water-soluble potassium fulvic acid, the grade I water-soluble potassium fulvic acid is wrapped with a second layer of binding water agent, the second layer of binding water agent is adhered to grade II water-soluble and grade I water-soluble potassium fulvic acid, forming a multi-layer wrapped particle structure.

[0116] Through the improvement of the granulation process, after the adhesive water agent is dehydrated and dried, potassium humate and hydrolyzed polyacrylamide form a relatively stable and hard shell layer, which has relatively poor water solubility, dissolves slowly in the pre-buried soil, and swells when absorbing water. The potassium humate inside and between the layers has a smaller molecular weight and dissolves first, and is slowly released into the soil through the shell layer, thereby realizing the slow release of potassium fertilizer; a space for storing water and fertilizer is formed in the shell layer, and it is not easy to directly adhere to the roots for a long time, and will not cause soil collapse and firmness or exposed roots.

[0117] Comparative Example 1:

[0118] In order to verify the fertilizer effect of the core-shell structure shaped particles of the present invention, the present invention sets a comparative example 1. According to the formula of Example 3, the raw materials of comparative example 4 are: 9 kg of potassium humate grade I, 0.3 kg of polyacrylamide, and 0.3 kg of Bacillus subtilis. They are directly mixed and granulated to verify the timeliness and water retention time of potassium fertilizer. Equivalent fertilizer particles are mixed with equivalent red soil respectively, and the soil moisture content is tested after watering. When the moisture content is less than 25%, it can be regarded as dehydration, and the water retention time is recorded; after dehydration, the soil is soaked for 15 minutes with pure water, and then the filtrate is filtered to release the filtrate, and the potassium ion concentration of the filtrate is recorded. When the potassium concentration is lower than 15 μg / ml, it can be considered that there is no potassium fertilizer effect. The fertilizer effect time and the corresponding potassium concentration are recorded, as shown in Table 3:

[0119] Table 3 Potassium fertilizer time-effectiveness experiment of the present invention

[0120]

[0121] In addition, the water retention time is: 43.5 h for Example 3, 78.1 h for Example 4, and 28.6 h for Comparative Example 1, which fully proves that the core-shell structure of the present invention has obvious scalability, especially after the potassium humate is graded, the core-shell structure is more stable and has a stronger water storage capacity.

[0122] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A production process of humic acid water-soluble fertilizer containing bacterial agent, characterized in that: The following steps are involved: S1. Classification of humic acid: Adding mineral fulvic acid into water and fully dissolving it to obtain a fulvic acid aqueous solution, adding a 5-10% polyacrylamide aqueous solution, the mass ratio of the fulvic acid aqueous solution to the polyacrylamide aqueous solution being 1:0.06-0.08, and after flocculation and sedimentation, obtaining a yellow-grey flocculated precipitate A and a clarified solution B; S2. Bacteria packaging: A sufficient amount of potassium oxide is added to the clarified solution B, and the solution is fully reacted for 30 minutes until the pH value of the system is 12-13. The solution is stirred and heated to 105-110°C to produce a viscous solution C with a viscosity of 3000-5000 cPs. The viscous solution C is cooled to room temperature, and the prepared dormant bacteria are added. The solution is stirred to produce needle-like crystals on the surface of the bacteria. The bacteria with yellow-white flocculent crystals on the surface are aged to obtain bacteria. The viscous solution D with a viscosity of 6000-8000 cPs is separated by centrifugation. The rest is vacuum dried at 50°C to obtain a semi-dormant bacteria E. S3. Preparation of potassium humate: The viscous liquid D was vacuum dried at 50°C to obtain potassium humate powder F; S4. Preparation of adhesive water: Mix equal masses of flocculation precipitate A and potassium oxide, add water 3-4 times the mass of the solid, stir and react in a water bath at 40-50°C for 2 hours, and obtain a bonding agent G with a viscosity of 1000-1500 cPs. The bonding agent G contains potassium fulvic acid and hydrolyzed polyacrylamide; S5. Preparation of fertilizer granules: Put the semi-dormant strain E into the disc granulator, adjust the machine angle and speed, and granulate; Spray the adhesive water G on the disc surface of the disc granulator, and complete the first granulation through continuous rotation, with a particle size of 1.5-2.0mm; During the rotation of the disc, potassium humate powder F is put into the feeding port of the disc granulator for secondary coating and granulation; Re-adjust the angle of the disc to increase it, spray the adhesive water G on its surface again, and complete the granulation, with a particle size of 4-4.5 mm; S6. Drying of fertilizer granules: The S5 formed particles are introduced into a vibrating screen with a mesh size of 60, and particles within the qualified units are screened by vibration; The granules are introduced into the dryer for secondary drying, and the temperature is maintained at 50°C for low temperature drying; Take some particles and put them into the moisture detector to test the moisture content of the particles. When the moisture content is ≤10%, the drying is completed and the formed particles are obtained. They are introduced into the material filling machine, packed according to the requirements and stored.

2. The production process of a humic acid water-soluble fertilizer containing a bacterial agent according to claim 1, characterized in that: In the formation of the first granules in S5, the semi-dormant bacteria E is mixed with chopped straw powder, and the mass ratio of the chopped straw powder to the semi-dormant bacteria E is 0-0.2:

1.

3. The production process of a humic acid water-soluble fertilizer containing a bacterial agent according to claim 1, characterized in that: In the secondary encapsulation granulation in S5, potassium humate powder F is mixed with inorganic fertilizer powder, the inorganic fertilizer powder includes phosphate fertilizer or nitrogen fertilizer, the mass ratio of inorganic fertilizer powder to potassium humate powder F is 0-0.3:1, and the amount of inorganic fertilizer powder is not 0.

4. The production process of a humic acid water-soluble fertilizer containing a bacterial agent according to claim 1, characterized in that: The adhesive water agent G is also mixed with an inorganic binder, the inorganic binder is bentonite or attapulgite, and the inorganic binder accounts for no more than 20% of the total mass of the adhesive water agent G.

5. A humic acid water-soluble fertilizer containing a bacterial agent prepared by the production process of claim 1, characterized in that: The method comprises the following components by weight: 85-90 parts of humic acid, 3-7 parts of bacterial strains, 1-3 parts of adhesive, and the rest is water; Humic acid is divided into multiple parts. The adhesive, part of humic acid and water are mixed to form an adhesive water agent. Part of humic acid and all bacteria are mixed to form a particle core. The particle core is wrapped with a first layer of adhesive water agent. The first layer of adhesive water agent is adhered to the first layer of humic acid adhesion. The first layer of humic acid adhesion is wrapped with a second layer of adhesive water agent. The second layer of adhesive water agent is adhered to the second layer of humic acid adhesion, thus forming a multi-layer wrapped particle structure.

6. The humic acid water-soluble fertilizer containing bacterial agent according to claim 5, characterized in that: The bacterial species is an alkali-resistant Bacillus, and the Bacillus includes at least one of Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, Bacillus azotobacter, Bacillus sphaericus or Bacillus laterosporus.

7. The humic acid water-soluble fertilizer containing bacterial agent according to claim 5, characterized in that: The adhesive is specifically partially hydrolyzed polyacrylamide with a hydrolysis degree of 20-25%, which is obtained by alkaline catalytic hydrolysis of polyacrylamide with a concentration of 5-10%. The adhesive aqueous agent contains hydrolyzed polyacrylamide and potassium humate.

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