Soil conditioner for promoting crop growth and preparation process thereof

Abstract

The invention relates to a soil conditioner for promoting crop growth and a preparation process thereof, and belongs to the technical field of soil conditioning. A formula of the soil conditioner comprises the following components in parts by weight: 4-6 parts of a microbial complex microbial inoculant, 10-15 parts of humic acid, 30-50 parts of modified charcoal, 5-8 parts of ulva oligosaccharide, 3-5 parts of gamma-polyglutamic acid and 10-12 parts of bentonite, and the microbial complex microbial inoculant is prepared from bacillus marinus and pseudomonas kirschner in a mass ratio of 1: 1. The soil conditioner prepared by the invention can comprehensively improve soil fertility and crop stress resistance, thereby effectively promoting crop growth.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil conditioning, and relates to a soil conditioner for promoting crop growth and a preparation process thereof. BACKGROUND

[0002] With the global population growth and the development of agricultural intensification, the problem of soil degradation is becoming increasingly serious. It is reported that about 33% of the soil in the world is in a moderate to severe degradation state due to excessive tillage, misuse of chemical fertilizers, heavy metal pollution and salinization, etc., resulting in a 10%-40% reduction in crop yield and threatening food security. Traditional soil improvement techniques such as increasing the application of organic fertilizer have defects such as low nutrient utilization rate, insufficient stress resistance and long ecological restoration period.

[0003] The mainstream soil conditioner on the market at present mainly has a single functional component, which is difficult to meet the restoration needs of compound degraded soil. For example, although microbial agents can activate nutrients, they are easily affected by the environment, have a low survival rate, and lack the ability to repair heavy metal pollution; the adsorption performance of biochar-based materials is strong, but they lack the function of nutrient release, and long-term use may lead to imbalance of soil carbon and nitrogen ratio; chemical chelating agents can fix heavy metals, but they may destroy soil microbial communities and cause secondary pollution.

[0004] Therefore, it is urgent to develop a soil conditioner for promoting crop growth and a preparation process thereof. SUMMARY

[0005] The purpose of the present application is to provide a soil conditioner for promoting crop growth and a preparation process thereof, which has the characteristics of efficiently promoting crop growth.

[0006] The purpose of the present application can be achieved by the following technical solutions: A soil conditioner for promoting crop growth, the formula of the soil conditioner is as follows: 4-6 parts of microbial composite bacteria, 10-15 parts of humic acid, 30-50 parts of modified biochar, 5-8 parts of ulvan oligosaccharide, 3-5 parts of gamma-polyglutamic acid, and 10-12 parts of bentonite, in terms of weight.

[0007] As a preferred technical solution of the present application, the microbial composite bacteria is Bacillus oceanisediminis and Pseudomonas knackmussii with a mass ratio of 1:1.

[0008] As a preferred technical solution of the present application, the preparation method of the microbial composite bacteria is as follows, S3-1: Place the Bacillus oceanisediminis in the liquid culture medium A and shake culture at 30°C and 150-200 rpm, until the bacterial concentration reaches 10 9After centrifugation, the bacteria A is collected and dried; S3-2: Pseudomonas koreensis is placed in liquid medium B and cultured at 25 ℃, 150-170 rpm, and the bacteria concentration reaches 10 8 After centrifugation, the bacteria B is collected and dried; S3-3: The bacteria A and the bacteria B are mixed in a mass ratio of 1:1, sodium alginate is added, and freeze-drying is performed at -30 to -50 ℃ for 12 h to obtain the microbial compound agent.

[0009] As a preferred technical solution of the present application, the formula of the liquid medium A in S3-1 is 5-10 g / L of glucose, 5-10 g / L of sucrose, 1-3 g / L of yeast powder, 1-2 g / L of protein powder, 0.01-0.1 g / L of magnesium chloride, 0.1-0.3 g / L of potassium chloride, 0.1-0.3 g / L of potassium dihydrogen phosphate, 10-12 g / L of NaCl, and deionized water in excess.

[0010] As a preferred technical solution of the present application, the formula of the liquid medium B in S3-2 is 2-5 g / L of glucose, 5-10 g / L of tryptone, 1-5 g / L of yeast extract, 3-5 g / L of sodium chloride, 1-3 g / L of potassium dihydrogen phosphate, 0.1-0.3 g / L of magnesium sulfate, 0.01-0.1 g / L of vitamin B1, 0.01-0.02 g / L of ferric phosphate, and deionized water in excess.

[0011] As a preferred technical solution of the present application, the addition amount of sodium alginate in S3-3 is 10-15% of the total mass of the bacteria A and the bacteria B.

[0012] As a preferred technical solution of the present application, the preparation method of the modified biochar is as follows, The rice straw and the rice husk are mixed in a mass ratio of 1:(3-5) and pyrolyzed at 500-550 ℃ for 2-3 h to prepare a crude biochar, the crude biochar is mixed with 30-50 wt% of bamboo vinegar liquid diluent, stirred at 45-50 ℃ for 6-8 h, washed with deionized water until the pH is neutral, dried at 80-100 ℃, and pulverized to 40-60 mesh to obtain the modified biochar.

[0013] As a preferred technical solution of the present application, the crude biochar is mixed with the bamboo vinegar liquid diluent in a mass ratio of 1:(5-10).

[0014] A preparation process of a soil conditioner for promoting crop growth, the specific steps of the preparation process are as follows, S9-1: The microbial complexing agent is added to the modified biochar according to the formula proportion, mixed at 28~32 ℃ for 3~5 h, bentonite and humic acid are added and mixed for 10~15 min, then ulvan oligosaccharide and gamma-polyglutamic acid are added and mixed for 10~15 min, to obtain a mixture; S9-2: Spray atomized water into the mixture and stir, use a double-roller extrusion granulator to granulate at room temperature, form wet granules with a particle size of 3~4 mm, dry the wet granules at 45~50 ℃ until the water content is less than 12%, to obtain the soil conditioner.

[0015] As a preferred technical solution of the present application, the spraying of atomized water in S9-2 controls the total water content of the material to be 15%~18%.

[0016] The microbial complexing agent is compounded by marine bacillus and pseudomonas koreensis according to a mass ratio of 1:1. Marine bacillus has stronger stress resistance and can form spores to survive in harsh environments, thereby improving the microenvironment for the survival of subsequent microorganisms. Pseudomonas koreensis is a rhizosphere growth-promoting bacterium with fast reproduction speed and strong competition ability, but its survival stability in soil is relatively poor. Marine bacillus first improves the soil physical environment for pseudomonas koreensis, and the latter can rapidly reproduce by utilizing rhizosphere exudates, together occupying the rhizosphere niche, effectively excluding and inhibiting the invasion of pathogenic bacteria, and achieving faster and more stable root colonization.

[0017] Marine bacillus produces extracellular polysaccharides and other substances, which can significantly improve the soil aggregate structure, relieve hardening, and enhance the water and fertilizer retention capacity. It also has the potential for phosphorus and potassium solubilization and nitrogen fixation. Pseudomonas koreensis can efficiently secrete organic acids and phosphatase, etc., to convert the fixed ineffective phosphorus and potassium in the soil into plant available forms, greatly improving the fertilizer utilization rate. At the same time, it can produce siderophores, antagonize pathogenic bacteria, and secrete plant growth hormones to directly stimulate root growth.

[0018] The addition of sodium alginate forms a glassy matrix under freeze-drying conditions, encapsulates the bacterial cell membrane, prevents mechanical damage caused by ice crystal formation, and improves the survival rate of the bacterial agent after freeze-drying. The guluronic acid in sodium alginate interacts with the phospholipid bilayer of the bacterial cell membrane, enhancing membrane fluidity and improving tolerance to high temperature and high salt. During the use of the conditioner, sodium alginate slowly degrades, continuously releasing alginate polysaccharides, mannitol, and other carbon sources, providing long-term nutritional support for the bacteria. The carboxyl group of sodium alginate and the hydroxyl group on the surface of biochar are combined through hydrogen bonds, enhancing the adhesion of the bacterial agent to biochar and reducing the loss of bacterial cells after application. The mannitol produced by the degradation of sodium alginate can induce crops to produce stress-related proteins, forming a dual protection network of stress resistance and disease resistance with the disease-related proteins induced by ulvan oligosaccharides, and comprehensively improving the stress resistance of crops. In addition, the carboxyl group of sodium alginate and the amino group of γ-polyglutamic acid form a complex network through electrostatic interaction, enhancing the stability of the soil water film.

[0019] Although the crude biochar generated by direct pyrolysis of rice straw and rice husk has a porous structure, its specific surface area is small and the pore connectivity is poor, which limits its efficient adsorption of nutrients and water. During the stirring process at 45-50℃, the organic acids in the diluted bamboo vinegar solution further open up the pores of the biochar through etching, forming more micropores and mesopores, which increases the specific surface area of the biochar. This allows the modified biochar to have higher adsorption capacity for NH4 + , NO3 - , and other nutrient ions, increased water holding capacity, and significantly enhanced soil water and fertilizer retention capacity. Phenolic and ketonic substances in bamboo vinegar react with the surface of biochar during heat treatment, introducing more oxygen-containing functional groups such as hydroxyl and carboxyl groups. These functional groups fix NH4 + , K + , and other cations in the soil through ion exchange and complexation, reducing nutrient leaching; at the same time, when the crop roots secrete organic acids, the functional groups release nutrients through protonation, achieving sustained supply. In addition, the weak acidity of bamboo vinegar neutralizes part of the basic groups of biochar, and the surface oxygen-containing functional groups adjust soil pH through protonation / deprotonation reactions, reducing soil pH and electrical conductivity in saline-alkali soils, effectively alleviating salt stress.

[0020] The addition of humic acid can increase soil aggregate structure, improve aeration and water retention; chelate metal ions such as iron and aluminum in the soil, reduce the fixation of nutrients such as phosphorus and zinc, and improve the utilization rate; stimulate crop root growth and enhance nutrient absorption capacity.

[0021] Ulvan oligosaccharide can activate the immune system of crops, enhance resistance to diseases, drought, and saline-alkali; at the same time, stimulate the secretion of auxin by roots, promote the growth of lateral roots and root hairs, and expand the absorption area; also can improve the absorption efficiency of crops to nitrogen, phosphorus, and potassium.

[0022] Gamma-polyglutamic acid can adsorb more than 1000 times its own weight of water to form a hydrogel to slowly release water; at the same time, it can adsorb ammonium and potassium cations in the soil, reduce nutrient loss, and extend the fertilizer effect; it can also synergize with humic acid and biochar to achieve long-term and quick-release compound fertilizer supply.

[0023] Bentonite can fill soil pores, reduce water evaporation, and maintain air permeability; it can also protect microbial inoculants as a carrier, reducing the damage of environmental stress such as ultraviolet light and high temperature; in addition, bentonite can adsorb organic matter such as humic acid and gamma-polyglutamic acid, slowing down the decomposition rate and extending the action time.

[0024] The preparation process of the present application first mixes the microbial compound inoculant with modified biochar at 28-32℃, using the porous structure of biochar as a carrier for microorganisms to avoid subsequent mechanical shear force damaging the cell membrane. Bentonite and humic acid are added later, using the layered structure of bentonite to adsorb small molecular organic acids in humic acid to form mineral-organic complexes, reducing the volatilization loss of humic acid during storage. Ulvan oligosaccharide and gamma-polyglutamic acid are added last to avoid excessive adsorption with the carboxyl and hydroxyl groups on the surface of biochar, ensuring that they can be evenly distributed on the surface of the granules during subsequent granulation, quickly exerting their stress resistance induction and water retention functions.

[0025] The beneficial effects of the present application are: The present application uses a microbial compound inoculant, among which marine bacillus has strong stress resistance, improves the soil environment, and pseudomonas kleda reproduces quickly and has strong phosphorus and potassium solubilizing ability, both of which occupy the rhizosphere niche, inhibit pathogenic bacteria, and the former solubilizes phosphorus and nitrogen, improves the granule, and the latter secretes hormones to promote root growth; sodium alginate forms a glassy matrix to protect the bacterial cells, improves the survival rate and stress resistance of freeze-dried bacteria, provides a carbon source after degradation, induces stress resistance proteins, and also enhances the adhesion of the inoculant to biochar and the stability of the water retention membrane.

[0026] The modified biochar in the formula is etched with bamboo vinegar, increasing its specific surface area, adsorption capacity, and water holding capacity, and enabling the oxygen-containing functional groups to provide sustained nutrient supply; humic acid improves soil structure and nutrient utilization rate, stimulates root growth; ulvan oligosaccharide enhances crop stress resistance and nutrient absorption; gamma-polyglutamic acid efficiently retains water and slowly releases nutrients; bentonite reduces water evaporation, protects the inoculant, and extends the action time of organic matter; the components in the formula synergize to comprehensively improve soil fertility and crop stress resistance, effectively promoting crop growth.

[0027] The preparation process realizes synergistic effect of multiple components through step-by-step mixing, the microbial compound inoculant is mixed with modified biochar first, the porous structure of the biochar is used to protect the bacterial bodies from mechanical damage and improve the survival rate; the bentonite and humic acid are added in gradient, the layered structure is used to adsorb small-molecule organic acids to form mineral-organic complex and reduce the volatile loss during storage; finally, the ulvan oligosaccharide and gamma-polyglutamic acid are added to avoid excessive adsorption by the biochar and ensure uniform distribution on the surface of the granules after granulation, so that the functions of stress resistance induction and efficient water retention can be quickly exerted. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0029] In the examples and comparative examples of the present application: Bacillus oceanisediminis: purchased from Ningbo Mingzhou Biotechnology Co., Ltd., with the product number B66451; Pseudomonas knackmussii: purchased from Ningbo Mingzhou Biotechnology Co., Ltd., with the product number B69309 Humic acid: purchased from Shanghai Bangcheng Chemical Co., Ltd.; Ulvan oligosaccharide: purchased from Wuhan Baierde Biotechnology Co., Ltd., from Enteromorpha, with a cut-off value of 650 DA~1 kDA; Gamma-polyglutamic acid: purchased from Wuhan Dongkangyuan Technology Co., Ltd.; Bamboo vinegar: purchased from Hubei Chengfeng Chemical Co., Ltd.; Bentonite: purchased from Shanghai Pu Zhen Biotechnology Co., Ltd.

[0030] The formula of the liquid culture medium A is glucose 7.5 g / L, sucrose 7.5 g / L, yeast powder 2 g / L, protein powder 1.5 g / L, magnesium chloride 0.05 g / L, potassium chloride 0.2 g / L, potassium dihydrogen phosphate 0.2 g / L, NaCl 11 g / L and deionized water in balance.

[0031] The formula of the liquid culture medium B is glucose 3.5 g / L, tryptone 7.5 g / L, yeast extract 3.5 g / L, sodium chloride 4 g / L, potassium dihydrogen phosphate 2 g / L, magnesium sulfate 0.2 g / L, vitamin B1 0.05 g / L, ferric phosphate 0.015 g / L and deionized water in balance.

[0032] Example 1 A soil conditioner for promoting crop growth, the formula of the soil conditioner is as follows, microbial complex inoculant 5 parts, humic acid 12.5 parts, modified biochar 40 parts, ulvan oligosaccharide 6.5 parts, gamma-polyglutamic acid 4 parts, bentonite 11 parts.

[0033] The microbial complex inoculant is bacillus marinus and pseudomonas koreensis with a mass ratio of 1:1, and the preparation method of the microbial complex inoculant is as follows, S3-1: The bacillus marinus is placed in liquid medium A and cultured at 30°C and 175 rpm, and when the bacterial concentration reaches 10 9 CFU / mL, centrifugal collection and drying are performed to obtain bacterial body A; S3-2: The pseudomonas koreensis is placed in liquid medium B and cultured at 25°C and 160 rpm, and when the bacterial concentration reaches 10 8 CFU / mL, centrifugal collection and drying are performed to obtain bacterial body B; S3-3: The bacterial body A and the bacterial body B are mixed in a mass ratio of 1:1, 12.5% of sodium alginate of the total mass of the bacterial body A and the bacterial body B is added, and freeze-drying is performed at -40°C for 12h to obtain the microbial complex inoculant.

[0034] The preparation method of the modified biochar is as follows, The rice straw and rice husk are mixed in a mass ratio of 1:4 and pyrolyzed at 520°C for 2.5h to prepare a crude biochar, the crude biochar is mixed with 40wt% bamboo vinegar diluent in a mass ratio of 1:7.5, stirred at 47°C for 7h, washed with deionized water until the pH is neutral, dried at 90°C, and pulverized to 50 mesh to obtain the modified biochar.

[0035] A preparation process of a soil conditioner for promoting crop growth, the specific steps of the preparation process are as follows, S9-1: The microbial complex inoculant is added to the modified biochar according to the formula ratio, mixed at 30°C for 4h, bentonite and humic acid are added and mixed for 12.5min, and then ulvan oligosaccharide and gamma-polyglutamic acid are added and mixed for 12.5min to obtain a mixture; S9-2: Atomized water is sprayed into the mixture and stirred, the total water content of the material is controlled to be 17%, a double-roller extrusion granulator is used to granulate at room temperature to form wet particles with a particle size of 3.5mm, and the wet particles are dried at 47°C until the water content is less than 12% to obtain the soil conditioner.

[0036] Example 2 A soil conditioner for promoting crop growth, the formula of the soil conditioner is as follows, in parts by weight, microbial complex inoculant 4 parts, humic acid 10 parts, modified biochar 30 parts, ulvan oligosaccharide 5 parts, gamma-polyglutamic acid 3 parts, bentonite 10 parts.

[0037] The microbial complex inoculant is a mixture of bacillus marinus and pseudomonas koreensis in a mass ratio of 1:1, and the preparation method of the microbial complex inoculant is as follows, S3-1: The bacillus marinus is placed in liquid medium A and cultured at 30°C and 150 rpm, and when the concentration of the bacterial body reaches 10 9 CFU / mL, centrifugal collection and drying are performed to obtain bacterial body A; S3-2: The pseudomonas koreensis is placed in liquid medium B and cultured at 25°C and 150 rpm, and when the concentration of the bacterial body reaches 10 8 CFU / mL, centrifugal collection and drying are performed to obtain bacterial body B; S3-3: The bacterial body A and the bacterial body B are mixed in a mass ratio of 1:1, 10% of sodium alginate based on the total mass of the bacterial body A and the bacterial body B is added, and freeze-drying is performed at -30°C for 12 h to obtain the microbial complex inoculant.

[0038] The preparation method of the modified biochar is as follows, The rice straw and rice husk are mixed in a mass ratio of 1:3 and pyrolyzed at 500°C for 2 h to prepare a crude biochar, the crude biochar is mixed with 30 wt% of bamboo vinegar diluent in a mass ratio of 1:5, stirred at 45°C for 6 h, washed with deionized water until the pH is neutral, dried at 80°C, and pulverized to 40 mesh to obtain the modified biochar.

[0039] A preparation process of a soil conditioner for promoting crop growth, the specific steps of the preparation process are as follows, S9-1: The microbial complex inoculant is added to the modified biochar according to the formula ratio, mixed at 28°C for 3 h, bentonite and humic acid are added, mixed for 10 min, and then ulvan oligosaccharide and gamma-polyglutamic acid are added, and mixed for another 10 min to obtain a mixture; S9-2: Atomized water is sprayed into the mixture and stirred, the total water content of the material is controlled to be 15%, a double-roller extrusion granulator is used to granulate at room temperature to form wet particles with a particle size of 3 mm, and the wet particles are dried at 45°C until the water content is less than 12% to obtain the soil conditioner.

[0040] Example 3 A soil conditioner for promoting crop growth, the formula of the soil conditioner is as follows, in parts by weight, microbial complex inoculant 6 parts, humic acid 15 parts, modified biochar 50 parts, ulvan oligosaccharide 8 parts, gamma-polyglutamic acid 5 parts, bentonite 12 parts.

[0041] The microbial complex inoculant is a mixture of bacillus marinus and pseudomonas koreensis in a mass ratio of 1:1, and the preparation method of the microbial complex inoculant is as follows, S3-1: The bacillus marinus is placed in liquid medium A and cultured at 30°C and 200 rpm, and when the concentration of the bacterial body reaches 10 9 CFU / mL, it is centrifuged and dried to obtain bacterial body A; S3-2: The pseudomonas koreensis is placed in liquid medium B and cultured at 25°C and 170 rpm, and when the concentration of the bacterial body reaches 10 8 CFU / mL, it is centrifuged and dried to obtain bacterial body B; S3-3: The bacterial body A and the bacterial body B are mixed in a mass ratio of 1:1, 15% of sodium alginate based on the total mass of the bacterial body A and the bacterial body B is added, and the mixture is freeze-dried at -50°C for 12 h to obtain the microbial complex inoculant.

[0042] The preparation method of the modified biochar is as follows, The rice straw and rice husk are mixed in a mass ratio of 1:5 and pyrolyzed at 550°C for 3 h to obtain crude biochar, the crude biochar is mixed with 30-50 wt% bamboo vinegar diluent in a mass ratio of 1:10, stirred at 50°C for 8 h, washed with deionized water until the pH is neutral, dried at 100°C, and ground to 60 mesh to obtain the modified biochar.

[0043] A preparation process of a soil conditioner for promoting crop growth, the specific steps of the preparation process are as follows, S9-1: The microbial complex inoculant is added to the modified biochar according to the formula ratio, mixed at 32°C for 5 h, bentonite and humic acid are added and mixed for 15 min, and then ulvan oligosaccharide and gamma-polyglutamic acid are added and mixed for another 15 min to obtain a mixture; S9-2: Atomized water is sprayed into the mixture and stirred, the total water content of the material is controlled to be 18%, a double-roller extrusion granulator is used to granulate at room temperature to form wet granules with a particle size of 4 mm, and the wet granules are dried at 50°C until the water content is less than 12% to obtain the soil conditioner.

[0044] Comparative Example 1 Only bacillus marinus is used, and the remaining steps are the same as those of Example 1.

[0045] Comparative Example 2 Only Pseudomonas kirch was used, and the remaining steps were the same as in Example 1.

[0046] Comparative Example 3 Sodium alginate was not added in the preparation of the microbial compound inoculant, and the remaining steps were the same as in Example 1.

[0047] Comparative Example 4 In the preparation of modified biochar, bamboo vinegar diluent was not added, and the remaining steps were the same as in Example 1.

[0048] Comparative Example 5 Ulva oligosaccharide was not added during the preparation of the soil conditioner; the remaining steps were the same as in Example 1.

[0049] Comparative Example 6 γ-polyglutamic acid was not added during the preparation of the soil conditioner, and the remaining steps were the same as in Example 1.

[0050] Comparative Example 7 The soil conditioner was prepared using a one-step mixing method, with the remaining steps being the same as in Example 1.

[0051] Pot experiment Saline-alkali soil (EC=4.2 dS / m) with pH=8.2 was used as the experimental soil. Ten treatments were set up: Examples 1-3 and Comparative Examples 1-7, with each treatment replicated three times in a randomized block design. Soil conditioner was mixed at a rate of 2 g / kg of soil, thoroughly mixed, and then placed in plastic pots. Ten rice seeds were sown in each pot, and after germination, seedlings were thinned to 5 plants / pot. The cultivation conditions were: temperature 28±2℃, light 14 h / d, relative humidity 65%~70%, and regular watering to maintain soil moisture content at 18%~25%. Plant height was measured after 45 days of growth, and stem base diameter was measured with calipers. The experimental results are summarized in the table below.

[0052] Group Plant height (cm) Stem diameter (cm) Example 1 68.1±2.0 5.8±0.3 Example 2 67.2±1.6 5.7±0.5 Example 3 67.8±2.1 5.8±0.4 Comparative Example 1 62.3±1.9 5.2±0.2 Comparative Example 2 61.6±1.5 5.1±0.3 Comparative Example 3 58.4±2.3 4.9±0.2 Comparative Example 4 58.9±1.4 5.0±0.1 Comparative Example 5 63.3±2.0 5.3±0.2 Comparative Example 6 62.8±1.8 5.2±0.2 Comparative Example 7 59.4±1.3 5.1±0.2 The data above show that the rice plants with height and stem diameter of those treated in Examples 1-3 were higher than those treated in Comparative Examples 1-7, indicating that the soil conditioner prepared by this invention can effectively promote crop growth.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are still within the scope of the present invention.

Claims

1. A soil conditioner for promoting crop growth, characterized in that, The soil conditioner is formulated as follows, by weight: 4-6 parts of microbial compound inoculant, 10-15 parts of humic acid, 30-50 parts of modified biochar, 5-8 parts of Ulva oligosaccharide, 3-5 parts of γ-polyglutamic acid, and 10-12 parts of bentonite.

2. The soil conditioner for promoting crop growth according to claim 1, characterized in that, The microbial compound inoculant consists of Bacillus oceanisediminis and Pseudomonas knackmussii in a mass ratio of 1:

1.

3. The soil conditioner for promoting crop growth according to claim 1, characterized in that, The preparation method of the microbial compound inoculant is as follows: S3-1: Place marine Bacillus in liquid culture medium A and culture with shaking at 30 ℃ and 150~200 rpm until the bacterial concentration reaches 10. 9 After centrifuging and drying, CFU / mL was collected to obtain bacterial cells A; S3-2: Place *Pseudomonas krusei* in liquid medium B and incubate with shaking at 25 °C and 150–170 rpm until the bacterial concentration reaches 10⁻⁶. 8 After centrifuging and drying, CFU / mL was collected to obtain bacterial cells B; S3-3: Mix bacterial cells A and B at a mass ratio of 1:1, add sodium alginate, and freeze-dry at -30~-50 ℃ for 12 h to obtain the microbial compound inoculant.

4. The soil conditioner for promoting crop growth according to claim 3, characterized in that, The liquid culture medium A in S3-1 is formulated as follows: glucose 5-10 g / L, sucrose 5-10 g / L, yeast powder 1-3 g / L, protein powder 1-2 g / L, magnesium chloride 0.01-0.1 g / L, potassium chloride 0.1-0.3 g / L, potassium dihydrogen phosphate 0.1-0.3 g / L, NaCl 10-12 g / L, and deionized water to make up the remainder.

5. The soil conditioner for promoting crop growth according to claim 3, characterized in that, The liquid culture medium B in S3-2 has the following formula: glucose 2-5 g / L, tryptone 5-10 g / L, yeast extract 1-5 g / L, sodium chloride 3-5 g / L, potassium dihydrogen phosphate 1-3 g / L, magnesium sulfate 0.1-0.3 g / L, vitamin B1 0.01-0.1 g / L, ferric phosphate 0.01-0.02 g / L, and deionized water as the balance.

6. The soil conditioner for promoting crop growth according to claim 3, characterized in that, The amount of sodium alginate added in S3-3 is 10-15% of the total mass of bacterial cells A and B.

7. The soil conditioner for promoting crop growth according to claim 1, characterized in that, The method for preparing the modified biochar is as follows: Rice straw and rice husks are mixed at a mass ratio of 1:(3~5) and pyrolyzed at 500~550 ℃ for 2~3 h to produce crude biochar. The crude biochar is mixed with 30~50 wt% bamboo vinegar solution and stirred at 45~50 ℃ for 6~8 h. It is then washed with deionized water until the pH is neutral, dried at 80~100 ℃, and pulverized to 40~60 mesh to obtain the modified biochar.

8. The soil conditioner for promoting crop growth according to claim 7, characterized in that, The crude biochar and bamboo vinegar dilution are mixed at a mass ratio of 1:(5~10).

9. A preparation process for a soil conditioner for promoting crop growth as described in any one of claims 1 to 8, characterized in that, The specific steps of the preparation process are as follows. S9-1: Add the microbial compound agent to the modified biochar according to the formula ratio, mix at 28~32 ℃ for 3~5h, add bentonite and humic acid, mix for 10~15min, then add Ulva oligosaccharide and γ-polyglutamic acid, continue mixing for 10~15min to obtain the mixture; S9-2: Spray atomized water into the mixture and stir. Granulate the mixture at room temperature using a double-roller extrusion granulator to form wet granules with a particle size of 3-4 mm. Dry the wet granules at 45-50 ℃ until the moisture content is less than 12% to obtain the soil conditioner.

10. The preparation process of the soil conditioner for promoting crop growth according to claim 9, characterized in that, In S9-2, the atomized water is sprayed to control the total moisture content of the material to be 15%~18%.