Environment-friendly microbial soil conditioner and preparation method thereof

Abstract

The present application relates to the field of soil conditioning, in particular to an environment-friendly microbial soil conditioner and a preparation method thereof.The present application discloses an environment-friendly microbial soil conditioner and a preparation method thereof; first, a bacillus subtilis with high yield of antibacterial peptide is selected by ultraviolet radiation, and the bacillus subtilis is used as core material; sodium alginate and chitosan oligosaccharide are used as wall material to prepare microcapsules which have immune and killing effects on various soil fungi, bacteria and viruses.The chitosan oligosaccharide can also coordinate with heavy metal ions in acid soil, so the microcapsules prepared by the present application can not only change the soil flora, promote the growth of beneficial microorganisms, induce the plant to produce disease resistance, but also chelate heavy metal ions such as cadmium, lead and copper in the soil, thereby adjusting the soil pH and improving the soil quality.The soil conditioner prepared by mixing the microcapsules with bamboo charcoal powder, bactericide and wollastonite powder has a positive effect on soil fertility, soil purification and restoration, and disease prevention.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil conditioning, in particular to an environment-friendly microbial soil conditioner and a preparation method thereof. BACKGROUND

[0002] Soil conditioner is one or more substances that can adjust soil obstacles and improve soil nutrient conditions. Through reasonable application, it can effectively improve the properties of soil quality such as physics (soil structure, water and soil conservation capacity), chemistry (soil pH, soil salinization, heavy metal pollution, etc.), biology (microbial community diversity, soil enzyme activity, etc.), so as to meet the needs of various high-quality and efficient agricultural production activities. As early as in the traditional farming society, people learned to improve soil quality by applying lime, straw and soil replacement in production. With the gradual diversification and complication of soil problems, more and more people began to pay attention to the research of soil conditioner.

[0003] According to the function and purpose of soil conditioner, it can be divided into five categories, which are structure improver, water regulator, saline-alkali soil conditioner, acid soil conditioner and heavy metal pollution remediation agent. Among them, the structure improver is generally divided into two categories according to the source, namely natural and artificial synthesis; soil water regulator is used for soil water retention, and in recent years, there are also studies on using specific materials to prepare soil water increasing agent to absorb gaseous water for plant growth; acid soil conditioner mainly includes lime, mineral, microbial fertilizer, organic material, biochar and industrial and mining waste; saline-alkali soil conditioner mainly includes chemical conditioner, microbial conditioner, organic fertilizer, humic acid and zeolite; heavy metal pollution remediation agent can be divided into passivation remediation agent and leaching remediation agent, according to the physicochemical properties of passivation materials, the passivation remediation agent can be divided into inorganic, organic, biochar, new nano materials and composite materials, and according to the difference of leaching technology, the leaching remediation agent can be divided into inorganic solution cleaning agent, chelating agent and surfactant.

[0004] The existing soil conditioner has various types and complete functions, but also has the risk of use. Some soil conditioners contain artificial synthetic materials, although most scholars believe that these substances are harmless to soil, but the residues may have hidden dangers, such as polyacrylamide is non-toxic, but the monomer acrylamide after decomposition can damage the human body nerve; polyvinyl alcohol is difficult to be degraded in nature, which also causes plastic pollution. In addition, the existing soil conditioner has relatively single function, and often needs to be mixed to achieve the expected conditioning effect, so it is necessary to invent an environment-friendly soil conditioner. SUMMARY

[0005] The present application relates to the technical field of soil conditioning, in particular to an environment-friendly microbial soil conditioner and a preparation method thereof.

[0006] To solve the above technical problems, the present application provides the following technical invention: an environment-friendly microbial soil conditioner and a preparation method thereof, comprising the following steps:

[0007] Step 1: Move Bacillus subtilis into a sterile culture dish; after preheating the ultraviolet lamp for 10 minutes, place the culture dish while slowly stirring at a uniform speed; use ultraviolet breeding to select strains with a survival rate of 25-30% for dilution, culture, preliminary screening and rescreening to obtain high-yield Bacillus subtilis selected by ultraviolet; logarithmically culture the high-yield Bacillus subtilis selected by ultraviolet, remove the supernatant after centrifugation to obtain a bacterial suspension; then add paraffin, corn starch and water, stir uniformly to obtain a mixed solution A, and stand by;

[0008] Step 2: Mix water, chitosan oligosaccharide, calcium chloride and water-soluble surfactant, stir for 30-45 minutes at room temperature, then add to the mixed solution A, continue stirring at the same speed for 60 minutes; obtain a mixed solution B; mix the organic solvent, oil-soluble surfactant and crosslinking agent uniformly to obtain a mixed solution C;

[0009] Step 3: Add a sodium alginate solution to the mixed solution B, stir for 10-15 minutes, then immediately add the mixed solution C, use shear stirring while water-bath heating, rotary evaporation, filtration and drying to obtain microcapsules;

[0010] Step 4: Mix bamboo charcoal powder, fertilizer synergist, wollastonite powder and microcapsules to obtain the environment-friendly microbial soil conditioner.

[0011] Further, in step 1, the Bacillus subtilis is of the type Bacillus subtilis HS-A38 which can produce antibacterial peptides.

[0012] Further, in step 1, the ultraviolet breeding conditions are irradiation under a 15-20W ultraviolet lamp for 60-90 seconds, with an irradiation distance of 20-30 cm.

[0013] Further, in step 1, the content of each component in the mixed solution A is 2-3 parts of bacterial suspension, 1-2 parts of paraffin, 1-2 parts of corn starch and 20-30 parts of water by weight.

[0014] Further, in step 2, the content of each component in the mixed solution B is 20-30 parts of water, 3-4.5 parts of chitosan oligosaccharide, 0.4-1.6 parts of calcium chloride, 0.5-1 part of water-soluble surfactant and 0.5-1.2 parts of mixed solution A by weight.

[0015] Further, in step 2, the content of each component in the mixed solution C is 10-13 parts of organic solvent, 3-5 parts of oil-soluble surfactant and 1-2 parts of crosslinking agent by weight.

[0016] Further, in step 2, the water-soluble surfactant is any one of sodium dodecyl benzene sulfonate, Tween 80, sodium dodecyl sulfate and polyethylene glycol; the organic solvent is any one of n-hexane, cyclohexane, isooctane and C12-C30 fatty acid; the oil-soluble surfactant is any one of propylene glycol fatty acid ester, sorbitan sesquioleate and sorbitan monooleate; and the crosslinking agent is any one of glutaraldehyde, glyoxal, oxidized alginic acid, oxidized cyclodextrin, dialdehyde starch, tripolyphosphoric acid and citric acid.

[0017] Further, in step 2, the stirring speed is 500-1000 rpm.

[0018] Further, in step 3, the amount of each component is 4-5 parts of the mixed solution B, 1-2 parts of the sodium alginate solution and 0.5-1 part of the mixed solution C.

[0019] Further, in step 3, the water bath temperature is 50-60℃, the shear stirring speed is 5000-10000 rpm, and the shear stirring time is 24-48 h.

[0020] Further, in step 4, in the environment-friendly microbial soil conditioner, the content of each component is 40-50% of the bamboo charcoal powder, 20-25% of the fertilizer synergist, 20-25% of the wollastonite powder and 10-20% of the microcapsule.

[0021] Compared with the prior art, the present application has the following beneficial effects: the HS-A38 Bacillus subtilis is subjected to ultraviolet selection, and a Bacillus subtilis mutant strain with high yield of antibacterial peptides and stronger bactericidal ability is obtained; then chitosan oligosaccharide rich in positive charge cationic basic amino groups and sodium alginate with a large number of carboxyl groups on the molecular chain are used to form a polyelectrolyte membrane through mutual attraction of positive and negative charges, and a microcapsule is obtained. Since chitosan oligosaccharide is a green, harmless and pollution-free natural material, it can produce immunity and killing effect on various fungi, bacteria and viruses, and provide a good growth environment for the Bacillus subtilis mutant strain for delayed release. The traditional bactericide has the problems of short efficacy and easy drug resistance of disease bacteria, while the HS-A38 Bacillus subtilis mutant strain can secrete antibacterial peptides, and the bactericidal effect is more persistent. In addition, chitosan oligosaccharide can also coordinate with metal ions, so the microcapsule prepared by the present application can not only change the soil flora, promote the growth of beneficial microorganisms, induce the plant to produce disease resistance, but also chelate heavy metal ions such as cadmium, lead and copper in the soil, thereby improving the soil quality. The soil conditioner prepared by mixing the microcapsule with bamboo charcoal powder, bactericide and wollastonite powder has an irreplaceable role in fertilizing the land, improving the utilization rate of chemical fertilizers, purifying and repairing the soil, reducing crop diseases and improving crop quality. DETAILED DESCRIPTION

[0022] The technical inventions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0023] The main materials and their sources in the following embodiments are as follows: Bacillus subtilis HS-A38 from Shanghai Ditian Biological Technology; paraffin wax from Colaman, CAS No. 8002-74-2; corn starch from Tianlei Chemical Industry, CAS No. 9005-25-8; chitooligosaccharide from Haifeng Biological, CAS No. 148411-57-8, molecular weight 1000-3000; calcium chloride from Tianlei Chemical Industry, CAS No. 10043-52-4; Tween 80 from Younite Biological Technology, CAS No. 9005-65-6; isooctane from Macklin, CAS No. 540-84-1; propylene glycol fatty acid ester from Guangzhou Yongyi, CAS No. 1323-39-3; glutaraldehyde from Macklin, CAS No. 111-30-8; sodium alginate from Macklin, CAS No. 9005-38-3; bamboo charcoal powder from Hainuo Carbon Industry; fertilizer synergist selected as polyaspartic acid from Syngenta Chemical; wollastonite powder from San Yuan Silicon Material Co., Ltd.

[0024] Embodiment 1:

[0025] Step 1: Bacillus subtilis HS-A38 was moved into a sterile culture dish; after the ultraviolet lamp was preheated for 10 min, the culture dish was placed, and slow and uniform stirring was carried out at the same time; ultraviolet breeding was adopted, and the strains with a survival rate of 25-30% were selected for dilution, culture, preliminary screening and rescreening to obtain high-yield Bacillus subtilis selected by ultraviolet radiation; the high-yield Bacillus subtilis selected by ultraviolet radiation was logarithmically cultured, and the supernatant was removed after centrifugation to obtain a bacterial suspension; 20 g of the bacterial suspension, 10 g of paraffin wax, 10 g of corn starch and 200 g of water were stirred uniformly to obtain a mixed solution A, which was reserved after standing;

[0026] Step 2: 2 kg of water, 0.3 kg of chitooligosaccharide, 0.04 kg of calcium chloride and 0.05 kg of Tween 80 were mixed and stirred at room temperature for 30 min at a speed of 1000 rpm; then 0.05 kg of the mixed solution A was added, and the stirring was continued at the same speed for 60 min; a mixed solution B was obtained; 1 kg of isooctane, 0.3 kg of propylene glycol fatty acid ester and 0.1 kg of glutaraldehyde were mixed uniformly to obtain a mixed solution C;

[0027] Step 3: 1 kg of sodium alginate solution was added to 4 kg of mixed solution B, stirred for 10 min, then 0.5 kg of mixed solution C was immediately added, the water bath was heated to 50°C, and shearing stirring was used at a speed of 5000 rpm for 48 h; after rotary evaporation, filtration and drying, microcapsules were obtained;

[0028] Step 4: 40% bamboo charcoal powder, 25% fertilizer synergist, 25% wollastonite powder and 10% microcapsules were mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0029] Example 2:

[0030] Step 1: Bacillus subtilis HS-A38 was moved into a sterile culture dish; after the ultraviolet lamp was preheated for 10 min, the culture dish was placed while slowly and uniformly stirring; ultraviolet breeding was used, and strains with a survival rate of 25-30% were selected for dilution, culture, preliminary screening and rescreening to obtain high-yield Bacillus subtilis selected by ultraviolet radiation; the high-yield Bacillus subtilis selected by ultraviolet radiation was logarithmically cultured, and the supernatant was removed after centrifugation to obtain a bacterial suspension; 22 g of bacterial suspension, 14 g of paraffin, 17 g of corn starch and 230 g of water were stirred uniformly to obtain mixed solution A, and were placed for standby;

[0031] Step 2: 2.1 kg of water, 0.35 kg of chitosan oligosaccharide, 0.06 kg of calcium chloride and 0.08 kg of Tween 80 were mixed and stirred at room temperature for 35 min at a speed of 7500 rpm; then 0.08 kg of mixed solution A was added, and stirring was continued at the same speed for 60 min; mixed solution B was obtained; 1.3 kg of isooctane, 0.35 kg of propylene glycol fatty acid ester and 0.12 kg of glutaraldehyde were mixed uniformly to obtain mixed solution C;

[0032] Step 3: 1.2 kg of sodium alginate solution was added to 4.5 kg of mixed solution B, stirred for 12 min, then 0.6 kg of mixed solution C was immediately added, the water bath was heated to 55°C, and shearing stirring was used at a speed of 6000 rpm for 30 h, after rotary evaporation, filtration and drying, microcapsules were obtained;

[0033] Step 4: 40% bamboo charcoal powder, 25% fertilizer synergist, 20% wollastonite powder and 15% microcapsules were mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0034] Example 3:

[0035] Step 1: Bacillus subtilis HS-A38 is moved into a sterile culture dish; after the UV lamp is preheated for 10 minutes, the culture dish is placed while slow and uniform stirring is carried out; UV breeding is adopted, and the strains with a survival rate of 25-30% are selected for dilution, culture, primary screening and rescreening to obtain high-yield Bacillus subtilis selected by UV; the high-yield Bacillus subtilis selected by UV is logarithmically cultured, and the supernatant is removed after centrifugation to obtain a bacterial suspension; 28 g of the bacterial suspension, 16 g of paraffin, 15 g of corn starch and 300 g of water are stirred uniformly to obtain a mixed solution A, which is reserved after standing;

[0036] Step 2: 2.7 kg of water, 0.3 kg of chitooligosaccharide, 0.16 kg of calcium chloride and 0.1 kg of Tween 80 are mixed and stirred at room temperature for 45 min at a speed of 500 rpm; then 0.1 kg of mixed solution A is added, and stirring is continued at the same speed for 60 min; a mixed solution B is obtained; 1.3 kg of isooctane, 0.35 kg of propylene glycol fatty acid ester and 0.12 kg of glutaraldehyde are mixed uniformly to obtain a mixed solution C;

[0037] Step 3: 2 kg of sodium alginate solution is added to 5 kg of mixed solution B, stirred for 15 min, then 1 kg of mixed solution C is immediately added, the water bath is heated to 60°C, and shearing stirring is adopted at a speed of 5000 rpm for 48 h; after rotary evaporation, filtration and drying, microcapsules are obtained;

[0038] Step 4: 50% bamboo charcoal powder, 20% fertilizer synergist, 20% wollastonite powder and 10% microcapsules are mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0039] Example 4:

[0040] Step 1: Bacillus subtilis HS-A38 is moved into a sterile culture dish; after the UV lamp is preheated for 10 minutes, the culture dish is placed while slow and uniform stirring is carried out; UV breeding is adopted, and the strains with a survival rate of 25-30% are selected for dilution, culture, primary screening and rescreening to obtain high-yield Bacillus subtilis selected by UV; the high-yield Bacillus subtilis selected by UV is logarithmically cultured, and the supernatant is removed after centrifugation to obtain a bacterial suspension; 28 g of the bacterial suspension, 16 g of paraffin, 15 g of corn starch and 300 g of water are stirred uniformly to obtain a mixed solution A, which is reserved after standing;

[0041] Step 2: 2.7 kg of water, 0.3 kg of chitooligosaccharide, 0.16 kg of calcium chloride and 0.1 kg of Tween 80 are mixed and stirred at room temperature for 45 min at a speed of 500 rpm; then 0.1 kg of mixed solution A is added, and stirring is continued at the same speed for 60 min; a mixed solution B is obtained; 1.3 kg of isooctane, 0.35 kg of propylene glycol fatty acid ester and 0.12 kg of glutaraldehyde are mixed uniformly to obtain a mixed solution C;

[0042] Step 3: 2 kg of sodium alginate solution was added to 4 kg of mixed solution B, stirred for 15 min, then 0.5 kg of mixed solution C was immediately added, the water bath was heated to 55°C, and shearing stirring was used at a speed of 10000 rpm for 48 h. After rotary evaporation, filtration and drying, microcapsules were obtained;

[0043] Step 4: 45% bamboo charcoal powder, 25% fertilizer synergist, 20% wollastonite powder and 10% microcapsules were mixed to obtain an environmentally friendly microbial soil conditioner.

[0044] Example 5:

[0045] Step 1: Bacillus subtilis HS-A38 was moved into a sterile culture dish; after the ultraviolet lamp was preheated for 10 min, the culture dish was placed while slowly and uniformly stirring; ultraviolet breeding was used, and strains with a survival rate of 25-30% were selected for dilution, culture, preliminary screening and rescreening to obtain high-yield Bacillus subtilis selected by ultraviolet radiation; the high-yield Bacillus subtilis selected by ultraviolet radiation was logarithmically cultured, and the supernatant was removed after centrifugation to obtain a bacterial suspension; 23 g of bacterial suspension, 10 g of paraffin, 18 g of corn starch and 230 g of water were stirred uniformly to obtain mixed solution A, and were placed for standby;

[0046] Step 2: 2.8 kg of water, 0.4 kg of chitosan oligosaccharide, 0.09 kg of calcium chloride and 0.07 kg of Tween 80 were mixed and stirred at room temperature for 30 min at a speed of 800 rpm; then 0.12 kg of mixed solution A was added, and stirring was continued at the same speed for 60 min; mixed solution B was obtained; 2.8 kg of isooctane, 0.41 kg of propylene glycol fatty acid ester and 0.17 kg of glutaraldehyde were mixed uniformly to obtain mixed solution C;

[0047] Step 3: 1 kg of sodium alginate solution was added to 5 kg of mixed solution B, stirred for 14 min, then 1 kg of mixed solution C was immediately added, the water bath was heated to 60°C, and shearing stirring was used at a speed of 10000 rpm for 45 h. After rotary evaporation, filtration and drying, microcapsules were obtained;

[0048] Step 4: 42% bamboo charcoal powder, 24% fertilizer synergist, 24% wollastonite powder and 10% microcapsules were mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0049] Example 6:

[0050] Step 1: Bacillus subtilis HS-A38 is moved into a sterile culture dish; after the UV lamp is preheated for 10 minutes, the culture dish is placed while slow and uniform stirring is performed; UV breeding is adopted, and the strains with a survival rate of 25-30% are selected for dilution, culture, primary screening and re-screening to obtain high-yield Bacillus subtilis selected by UV; the high-yield Bacillus subtilis selected by UV is logarithmically cultured, and the supernatant is removed after centrifugation to obtain a bacterial suspension; 29 g of the bacterial suspension, 11 g of paraffin, 13 g of corn starch and 270 g of water are uniformly stirred to obtain a mixed solution A, which is reserved after standing;

[0051] Step 2: 2.6 kg of water, 0.35 kg of chitosan oligosaccharide, 0.09 kg of calcium chloride and 0.08 kg of Tween 80 are mixed and stirred at room temperature for 45 min at a speed of 860 rpm; then 0.07 kg of mixed solution A is added, and stirring is continued at the same speed for 60 min; a mixed solution B is obtained; 3 kg of isooctane, 0.3 kg of propylene glycol fatty acid ester and 0.1 kg of glutaraldehyde are uniformly mixed to obtain a mixed solution C;

[0052] Step 3: 1 kg of sodium alginate solution is added to 4.7 kg of mixed solution B, stirred for 15 min, and then 0.5-1 kg of mixed solution C is immediately added; the water bath is heated to 50°C, and shearing stirring is performed at a speed of 10,000 rpm for 48 h; after rotary evaporation, filtration and drying, microcapsules are obtained;

[0053] Step 4: 46% bamboo charcoal powder, 20% fertilizer synergist, 20% wollastonite powder and 14% microcapsules are mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0054] Comparative Example 1: No microcapsules are added.

[0055] 50% bamboo charcoal powder, 25% fertilizer synergist and 25% wollastonite powder are mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0056] Comparative Example 2: No chitosan oligosaccharide is added.

[0057] Step 1: Bacillus subtilis HS-A38 is moved into a sterile culture dish; after the UV lamp is preheated for 10 minutes, the culture dish is placed while slow and uniform stirring is performed; UV breeding is adopted, and the strains with a survival rate of 25-30% are selected for dilution, culture, primary screening and re-screening to obtain high-yield Bacillus subtilis selected by UV; the high-yield Bacillus subtilis selected by UV is logarithmically cultured, and the supernatant is removed after centrifugation to obtain a bacterial suspension; 29 g of the bacterial suspension, 11 g of paraffin, 13 g of corn starch and 270 g of water are uniformly stirred to obtain a mixed solution A, which is reserved after standing;

[0058] Step 2: 2.1 kg of water, 0.06 kg of calcium chloride were stirred at room temperature for 35 min at a speed of 7500 rpm; then 0.08 kg of mixed solution A was added, and stirring was continued for 60 min at the same speed; mixed solution B was obtained;

[0059] Step 3: 1.2 kg of sodium alginate solution was added to 4.5 kg of mixed solution B, and after stirring for 12 min, the water bath was heated to 55°C, while shear stirring was used at a speed of 6000 rpm for 30 h. After rotary evaporation, filtration and drying, microcapsules were obtained;

[0060] Step 4: 40% bamboo charcoal powder, 25% fertilizer synergist, 20% wollastonite powder and 15% microcapsules were mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0061] Comparative Example 3: Bacillus subtilis HS-A38 was directly inlaid.

[0062] Step 1: 28 g of Bacillus subtilis HS-A38 bacterial suspension, 16 g of paraffin, 15 g of corn starch and 300 g of water were stirred uniformly to obtain mixed solution A, and were left for standby;

[0063] Step 2: 2.7 kg of water, 0.3 kg of chitosan oligosaccharide, 0.16 kg of calcium chloride and 0.1 kg of Tween 80 were mixed and stirred at room temperature for 45 min at a speed of 500 rpm; then 0.1 kg of mixed solution A was added, and stirring was continued for 60 min at the same speed; mixed solution B was obtained; 1.3 kg of isooctane, 0.35 kg of propylene glycol fatty acid ester and 0.12 kg of glutaraldehyde were mixed uniformly to obtain mixed solution C;

[0064] Step 3: 2 kg of sodium alginate solution was added to 5 kg of mixed solution B, and after stirring for 15 min, 1 kg of mixed solution C was immediately added, and the water bath was heated to 60°C, while shear stirring was used at a speed of 5000 rpm for 48 h. After rotary evaporation, filtration and drying, microcapsules were obtained;

[0065] Step 4: 50% bamboo charcoal powder, 20% fertilizer synergist, 20% wollastonite powder and 10% microcapsules were mixed by weight to obtain an environmentally friendly microbial soil conditioner.

[0066] Experiment:

[0067] The environmentally friendly microbial soil conditioner prepared in the above Examples 1-6 and Comparative Examples 1-3 was used in the cadmium-contaminated acidic soil in the spring of February when the ground was thawed, 20 kg of which was used on 50 square meters of land for planting rape, twice a month, and sowed in the middle of April for cultivation. After 12 months, the physicochemical properties of the soil (the soil pH before conditioning was 5.72; the cadmium content was 0.18 mg / kg) and the growth of rape were detected. The cadmium metal ions were extracted by acetic acid solution extraction, the content of cadmium was measured by inductively coupled plasma emission spectrometer, the adsorption rate of cadmium was calculated according to the adsorption rate = 1- (the cadmium content after using the conditioner) / (the cadmium content before using the conditioner), and all the results are shown in the following table.

[0068]

[0069]

[0070] Conclusion: By comparing the data of Examples 1-6 and Comparative Examples 1, it can be seen that the soil conditioner prepared in the present application effectively improves the soil quality; the incidence of rape sclerotial disease is generally between 10-30%, and the ultraviolet breeding high-yield bacillus can secrete more antibacterial peptides, which, together with chitosan oligosaccharide, improve the soil environment and significantly reduce the incidence of rape. In addition, in the case of adding microcapsules, the chitosan oligosaccharide in the microcapsules has alkalinity, can chelate heavy metal ions in the soil, and at the same time adjust the acidic soil to neutral. Taking Example 2 as the reference group, the data of Comparative Example 2 shows that when the microcapsule wall material is only sodium alginate, the chelating effect of the microcapsule on heavy metal ions is greatly reduced, and the heavy metal ions in the soil can chelate with the antibacterial peptides secreted by the ultraviolet breeding bacillus, thereby limiting the bactericidal function of the antibacterial peptides; taking Example 3 as the reference, the data of Comparative Example 3 shows that the antibacterial performance of the antibacterial peptides secreted by the ultraviolet breeding bacillus is better.

[0071] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical inventions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an environmentally friendly microbial soil conditioner, characterized in that: Includes the following steps: Step 1: Ultraviolet selection of Bacillus subtilis with a survival rate of 25-30%; after logarithmic culture and centrifugation, the supernatant is removed to obtain a high-yielding Bacillus subtilis suspension; paraffin, corn starch and water are added, and after stirring evenly, mixed solution A is obtained and set aside to stand; Step 2: Mix and stir water, chitosan oligosaccharide, calcium chloride and water-soluble surfactant, add to mixed solution A, and continue stirring to obtain mixed solution B; mix organic solvent, oil-soluble surfactant and crosslinking agent evenly to obtain mixed solution C; Step 3: Add sodium alginate solution to mixed solution B, stir for 10-15 minutes, then immediately add mixed solution C, heat in a water bath while shearing and stirring, rotary evaporate, filter, and dry to obtain microcapsules; Step 4: Mix bamboo charcoal powder, fertilizer enhancer, wollastonite powder and microcapsules to obtain an environmentally friendly microbial soil conditioner; In step 1, the Bacillus subtilis strain is Bacillus subtilis HS-A38, which is capable of producing antimicrobial peptides; the conditions for ultraviolet selection are irradiation under a 15-20W ultraviolet lamp for 60-90 seconds at a distance of 20-30cm.

2. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 1, the content of each component in the mixed solution A, by weight, is 2-3 parts bacterial suspension, 1-2 parts paraffin, 1-2 parts corn starch, and 20-30 parts water.

3. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 2, the content of each component in the mixed solution B, by weight, is 20-30 parts water, 3-4.5 parts chitosan oligosaccharide, 0.4-1.6 parts calcium chloride, 0.5-1 part water-soluble surfactant, and 0.5-1.2 parts mixed solution A; the content of each component in the mixed solution C, by weight, is 10-13 parts organic solvent, 3-5 parts oil-soluble surfactant, and 1-2 parts crosslinking agent.

4. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 2, the water-soluble surfactant is any one of sodium dodecylbenzenesulfonate, Tween 80, sodium dodecyl sulfate, and polyethylene glycol; the organic solvent is any one of n-hexane, cyclohexane, isooctane, and C12-C30 fatty acids; the oil-soluble surfactant is any one of propylene glycol fatty acid ester, sorbitan sesquioleate, and sorbitan monooleate; and the crosslinking agent is any one of glutaraldehyde, glyoxal, oxidized alginic acid, oxidized cyclodextrin, dialdehyde starch, tripolyphosphate, and citric acid.

5. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 3, the amounts of each component, by weight, are 4-5 parts of mixed solution B, 1-2 parts of sodium alginate solution, and 0.5-1 part of mixed solution C.

6. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 3, the water bath temperature is 50-60℃, the shearing and stirring speed is 5000-10000 rpm, and the shearing and stirring time is 24-48h.

7. The method for preparing an environmentally friendly microbial soil conditioner according to claim 1, characterized in that: In step 4, the environmentally friendly microbial soil conditioner contains, by weight, 40-50% bamboo charcoal powder, 20-25% fertilizer enhancer, 20-25% wollastonite powder, and 10-20% microcapsules.

8. The soil conditioner prepared by the method of any one of claims 1 to 7 for preparing an environmentally friendly microbial soil conditioner.

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