Compound microbial agent for soil remediation and preparation method thereof

Abstract

The invention provides a compound microbial agent for soil remediation and a preparation method thereof, and relates to the technical field of soil remediation. The compound microbial agent for soil remediation is prepared from the following raw materials in percentage by mass: 5-15% of a liquid bacillus mucilaginosus agent, 5-15% of a liquid bacillus megatherium agent, 60-80% of a liquid bacillus subtilis agent, 6-10% of a compound extract and 1-3% of a microbial agent protective agent, wherein the sum of the mass percentages of the raw materials is 100%; the microbial agent protective agent is prepared from the following raw materials in percentage by mass: 0.1 to 1.5 percent of CaCl2, 1 to 3 percent of chitosan, 0.1 to 1.5 percent of boric acid, 0.1 to 1.5 percent of PBS (Phosphate Buffer Solution) and the balance of water. The compound microbial agent for soil remediation is simple in preparation process, low in cost and remarkable in acting effect, the microbial agent protective agent and the compound extract have a good synergistic effect, the stability of the compound microbial agent for soil remediation can be remarkably improved, and the soil remediation effect is improved. The compound microbial agent for soil remediation has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and in particular to a composite microbial agent for soil remediation and a preparation method thereof. Background Art

[0002] In traditional agricultural planting, long-term excessive application of chemical fertilizers has become a common phenomenon, which not only leads to the aggravation of secondary salinization of soil, but also makes the problem of soil compaction increasingly serious. The scope of soil salinization and alkalization is constantly expanding, which has a profound impact on agricultural production and the ecological environment. First, excessive application of chemical fertilizers will destroy the soil structure. The lack of organic matter and humus in chemical fertilizers will cause the soil aggregate structure to be destroyed, the soil to become compacted, and the air permeability and water retention will decrease, which will eventually lead to soil compaction. The compacted soil is not conducive to the growth of crop roots, affects the ability of crops to absorb water and fertilizer, and leads to a decrease in crop yield and quality. Secondly, excessive use of chemical fertilizers will lead to soil salt accumulation. Elements such as nitrogen, phosphorus, and potassium in chemical fertilizers are easy to consolidate in the soil to form insoluble compounds, leading to salt accumulation in the soil. These salts will inhibit the normal growth of crops and even cause crop death. In addition, soil salinization will affect the activities of soil microorganisms and destroy the balance of the soil ecosystem. In addition, the long-term use of chemical fertilizers will also lead to soil acidification and alkalization. The nitrification of nitrogen fertilizer in the soil will produce nitrates, increase the hydrogen ion concentration in the soil, and cause soil acidification. On the other hand, some physiologically acidic fertilizers such as calcium phosphate and ammonium sulfate will increase the H + The increase in soil acidification further exacerbates soil acidification. Soil acidification not only affects the growth of crops, but also leads to the release of harmful heavy metals in the soil, polluting the environment. In addition, in arid and semi-arid areas, the utilization of salinized soil is of great significance to agricultural production development, land management, and ecological environment protection. Therefore, inhibiting soil salinization and improving salinized soil are important issues that need to be solved urgently.

[0003] At the same time, with the continuous improvement of industrial level, the wastewater, smoke and solid waste discharged by factory industrial production contain a large amount of heavy metals. In addition, the mining of mineral resources, improper treatment of tailings and slag, and the presence of more mercury (Hg), cadmium (Cd), arsenic (As) and lead (Pb) impurities in fertilizers, as well as the accumulation of heavy metals in farmland due to long-term application, have led to the increasingly serious problem of heavy metal pollution in farmland.

[0004] At present, domestic scientific research institutions, researchers from fertilizer and agricultural planting technology companies have invested a lot of financial resources and energy in the remediation technology of soil compaction and degradation and soil pollution.

[0005] The invention patent with the publication number CN118459280A discloses an ecological restoration agent for improving soil fertility and a preparation method thereof. The raw materials of the ecological restoration agent for improving soil fertility are measured by mass, including: 40-60 parts of biomass, 5-9 parts of sulfided attapulgite, 3-7 parts of humic acid, 35-50 parts of animal feces, 5-8 parts of plant ash, 1.5-2 parts of water retaining agent and 2-5 parts of zeolite. Treating attapulgite in its disclosed manner can achieve the purpose of activating attapulgite, and increase the theoretical maximum adsorption capacity by increasing the interlayer distance and the specific surface area, thereby obtaining a more excellent heavy metal purification effect. The ecological restoration agent designed by it can cope with various problems such as soil compaction, salinization, pH imbalance, etc. encountered by crops during the planting process, and is particularly helpful in alleviating the adverse effects of heavy metals in the soil, and can promote the repair efficiency of degraded soil and improve soil fertility. However, the ecological restoration agent provided by this method is not a microbial soil restoration agent, and therefore does not have the advantages of microbial soil restoration agents such as improving soil fertility, improving soil structure, promoting plant growth, enhancing plant stress resistance, being environmentally friendly and pollution-free, and being sustainable.

[0006] The invention patent with publication number CN117923964A discloses a compacted plough repair agent and its preparation method and application method. The compacted plough repair agent includes 20-30 parts of cow dung, 5-15 parts of biochar, 2-12 parts of polyacrylamide, 2-12 parts of soybean lecithin liquid, 2-10 parts of zeolite powder, 20-30 parts of fungus residue, 2-10 parts of trace elements, 1-5 parts of fermented bacterial liquid, 1-5 parts of functional bacterial liquid, and 1-5 parts of adhesive. The compacted plough repair agent prepared by this method contains a variety of functional substances, the product is uniform, and has strong targeting. It can improve and repair the microhabitat of the plough layer in a targeted manner, improve the activity of soil microorganisms in the plough layer, promote soil particle aggregation, improve the conversion and fixation of organic carbon and the effectiveness of nutrients, and strengthen biological functions and carbon-increasing and fertilizer-retaining capabilities. The soil remediation agent provided by this method contains microbial components, but the bacterial species are not isolated and protected. Therefore, there is a risk of decreased activity of effective bacteria and corruption during the storage of the agent, decreased activity of effective bacteria during the use of the agent, and damage to the soil remediation effect.

[0007] Therefore, it is necessary to develop a composite microbial agent with wide adaptability, good soil improvement effect, and the ability to maintain good effective bacterial activity after long-term placement to prevent corruption and deterioration to overcome the problems existing in the existing technology. Summary of the invention

[0008] To solve the above problems, the present invention provides a composite microbial agent for soil remediation and a preparation method thereof. The present invention uses a composite extract and a microbial agent protective agent to enable the composite microbial agent to have good stability while having a good soil remediation effect. The composite microbial agent of the present invention can still maintain a high level of effective live bacteria after long-term storage.

[0009] The composite microbial agent for soil remediation of the present invention is composed of the following raw materials in percentage by mass:

[0010] 5% to 15% of liquid jelly-like bacillus agent, 5% to 15% of liquid bacillus megaterium agent, 60% to 80% of liquid bacillus subtilis agent, 6% to 10% of composite extract, 1% to 3% of microbial agent protective agent, and the sum of the mass percentages of the above raw materials is 100%.

[0011] Furthermore, the composite microbial agent for soil remediation comprises the following raw materials in percentage by mass:

[0012] Liquid jelly-like Bacillus agent 10%, liquid Bacillus megaterium agent 10%, liquid Bacillus subtilis agent 70%, compound extract 8%, microbial agent protective agent 2%.

[0013] Furthermore, the preparation method of the liquid bacterial agent is as follows: prepare a culture medium, and then inoculate jelly-like Bacillus, Bacillus megaterium, and Bacillus subtilis into a seed tank respectively, with an inoculation amount of 0.1% to 0.3%, a culture temperature of 35°C to 37°C, a rotation speed of 50 to 150 rpm, a pressure of 0.04 to 0.05 MPa, and a fermentation time of 4 to 6 hours; then transfer the culture to a fermentation tank respectively, with an inoculation amount of 1 to 3%, a culture temperature of 35°C to 37°C, a rotation speed of 20 to 50 rpm, a pressure of 0.04 to 0.05 MPa, and fermentation for 14 to 26 hours. During the fermentation process, observe the morphology of the bacteria through a microscope, and when it is found that the bacteria become shorter and more than 90% of the bacteria form spores, stop the fermentation to obtain a liquid jelly-like Bacillus bacterial agent, a liquid Bacillus megaterium bacterial agent, or a liquid Bacillus subtilis bacterial agent.

[0014] Furthermore, the culture medium of liquid jelly-like Bacillus includes the following raw materials: 2.5 g / L brown sugar, 5 g / L corn flour, 5 g / L soybean flour, 5 g / L yeast extract, 0.5 g / L CaCl2, 0.5 g / L MnSO4, 1 g / L K2HPO4, and the pH of the culture medium is 7.0.

[0015] Furthermore, the liquid culture medium of Bacillus megaterium includes the following raw materials: 2 g / L brown sugar, 20 g / L corn flour, 10 g / L soybean flour, 1.5 g / L K2HPO4, 0.5 g / L MgSO4, and 1.5 g / L CaCO3, and the pH of the culture medium is 7.5.

[0016] Furthermore, the liquid Bacillus subtilis culture medium includes the following raw materials: 15 g brown sugar, 40 g soybean meal, 20 g / L corn flour, 3 g / L K2HPO4, 0.5 g / L MgSO4, 1.5 g / L CaCO3, 0.5 g / L (NH4)2SO4, 0.2 g / L yeast powder, 0.2 g / L MnSO4, 0.1 g / L FeSO4, and the pH of the culture medium is 7.0.

[0017] Furthermore, the composite extract is composed of the following raw materials in percentage by mass:

[0018] 0.1% to 2% of wormwood extract, 0.1% to 1.5% of tea polyphenols, 1% to 2% of persimmon extract, 1% to 5% of bamboo extract, 1% to 2% of coltsfoot extract, 1% to 4% of honeysuckle extract, and the balance is water.

[0019] Preferably, the composite extract is composed of the following raw materials in percentage by mass:

[0020] 1% wormwood extract, 0.5% tea polyphenols, 1.5% persimmon extract, 3% bamboo extract, 1.5% coltsfoot extract, 2.5% honeysuckle extract, 90% water.

[0021] Furthermore, the preparation method of the composite extract is as follows: after evenly mixing wormwood extract, tea polyphenols, persimmon extract, bamboo extract, coltsfoot extract, honeysuckle extract and water in proportion, inoculating 10% of Bacillus subtilis, and sealing and anaerobic fermenting at 33°C to 37°C for 7 to 15 days, filtering to obtain the composite extract.

[0022] Furthermore, the microbial agent protective agent is composed of the following raw materials in percentage by mass:

[0023] CaCl2 0.1%-1.5%, chitosan 1%-3%, boric acid 0.1%-1.5%, PBS buffer 0.1%-1.5%, and the balance is water.

[0024] Preferably, the microbial agent protective agent is composed of the following raw materials in percentage by mass:

[0025] CaCl2 0.5%, chitosan 2%, boric acid 0.5%, PBS buffer 1%, and the balance is water.

[0026] Furthermore, the preparation method of the microbial agent protective agent is as follows: CaCl2, chitosan, boric acid, and PBS buffer are uniformly mixed and the pH is adjusted to 7.0.

[0027] Furthermore, the number of effective live bacteria in the composite microbial agent for soil remediation is ≥ 1 billion CFU / g.

[0028] The present invention also provides a method for preparing the composite microbial agent for soil remediation, which specifically comprises the following steps:

[0029] S1, mixing a liquid jelly-like Bacillus inoculum, a liquid Bacillus megaterium inoculum, and a liquid Bacillus subtilis inoculum in proportion to obtain a composite liquid inoculum;

[0030] S2. Add the composite extract and the microbial agent protective agent into the composite liquid agent and stir evenly to obtain a composite microbial agent for soil remediation.

[0031] Compared with the prior art, the beneficial technical effects of the present invention are:

[0032] The extracellular polysaccharide substances secreted by the composite microbial agent of the present invention can enhance the soil aggregate structure, improve soil permeability and water and fertilizer retention capacity, increase soil organic matter, and the assistance of multiple bacteria can improve the soil nutrient supply capacity, thereby achieving the control and repair of problems such as soil compaction, salinization and excessive heavy metal residues.

[0033] The microbial agent protective agent of the present invention has a relative encapsulation effect on different bacterial species, can form relatively independent bacterial bodies, and ensures the stability and activity of the bacterial bodies in the soil.

[0034] The ingredients of the composite extract of the present invention, such as wormwood, persimmon, bamboo, coltsfoot and honeysuckle, have the effects of antibacterial, antioxidation and promoting plant growth, and are helpful to improve the soil microbial environment and enhance the stress resistance of plants.

[0035] The composite microbial agent for soil remediation of the present invention has a simple preparation process, low cost and significant effect. The microbial agent protective agent and the composite extract have good synergistic effects, which can significantly improve the stability of the composite microbial agent for soil remediation, so that the composite microbial agent for soil remediation of the present invention has good application prospects. DETAILED DESCRIPTION

[0036] The technical solution provided by the present invention is further described below in conjunction with embodiments.

[0037] In a specific embodiment of the present invention, the culture medium of liquid jelly-like Bacillus comprises the following raw materials: 2.5 g brown sugar, 5 g corn flour, 5 g soybean powder, 5 g yeast extract, 0.5 g CaCl2, 0.5 g MnSO4, 1 g K2HPO4, and 1 L sterile water, and the pH value of the culture medium is 7.0; the culture medium of liquid megaterium comprises the following raw materials: 2 g brown sugar, 20 g corn flour, 10 g soybean powder, 1.5 g K2HPO4, 0.5 g MgSO4, 1.5 g CaCO3, and 1 L sterile water, and the pH value of the culture medium is 7.5; the culture medium of liquid Bacillus subtilis comprises the following raw materials: 15 g brown sugar, 40 g soybean meal, 20 g corn flour, 3 g K2HPO4, 0.5 g MgSO4, 1.5 g CaCO3, 0.5 g (NH4)2SO4, 0.2 g yeast powder, 0.2 g MnSO4, 0.1 g FeSO4 g, 1 L of sterile water, and the pH of the culture medium was 7.0.

[0038] The various microbial strains used in the specific embodiments of the present invention can be purchased from the market.

[0039] The wormwood extract in the specific embodiment of the present invention was purchased from Ji'an Rongsheng Plant Co., Ltd., tea polyphenols were purchased from Xi'an Zebang Biotechnology Co., Ltd., persimmon extract was purchased from Guangzhou Bofeng Chemical Co., Ltd., bamboo extract was purchased from Anji Leida Biological Products Co., Ltd., coltsfoot extract was purchased from Ningxia Lannuo Biotechnology Co., Ltd., and honeysuckle extract was purchased from Ningxia Lannuo Biotechnology Co., Ltd.

[0040] The biological potassium silicate bacterial agent used in the specific implementation manner of the present invention was purchased from Hebei Yantui Bioengineering Co., Ltd.

[0041] Example 1 A composite microbial agent for soil remediation, composed of the following raw materials in percentage by mass:

[0042] Liquid jelly-like Bacillus agent 10%, liquid Bacillus megaterium agent 10%, liquid Bacillus subtilis agent 70%, compound extract 8%, microbial agent protective agent 2%.

[0043] The preparation method of the liquid bacterial agent is as follows:

[0044] (1) Liquid jelly-like Bacillus inoculum: prepare a culture medium, inoculate the jelly-like Bacillus into a seed tank at an inoculation amount of 0.3%, and ferment for 6 hours at 35° C., 100 rpm, and 0.04 MPa. Then, transfer the culture to a fermentation tank, inoculate at an inoculation amount of 3%, and ferment for 24 hours at 37° C., 50 rpm, and 0.04 MPa to obtain a liquid jelly-like Bacillus inoculum;

[0045] (2) Liquid Bacillus megaterium inoculant: prepare a culture medium, inoculate Bacillus megaterium into a seed tank at an inoculation amount of 0.2%, and ferment at 37°C, 80 rpm, and 0.04 MPa for 4 h. Then transfer the culture to a fermentation tank at an inoculation amount of 1%, and ferment at 37°C, 40 rpm, and 0.04 MPa for 18 h to obtain a liquid Bacillus megaterium inoculant;

[0046] (3) Liquid Bacillus subtilis inoculant: prepare culture medium, inoculate Bacillus subtilis into seed tank with inoculation amount of 0.1%, and ferment for 4 h at 37° C., 100 rpm, and 0.05 MPa. Then transfer the culture into fermentation tanks with inoculation amount of 2%, and ferment for 18 h at 37° C., 50 rpm, and 0.05 MPa to obtain liquid Bacillus subtilis inoculant.

[0047] The preparation method of the composite extract is as follows: the following raw materials of wormwood extract (1%), tea polyphenols (0.5%), persimmon extract (1.5%), bamboo extract (3%), coltsfoot extract (1.5%), honeysuckle extract (2.5%) and water (90%) are mixed evenly in proportion, and then 10% of Bacillus subtilis is inoculated, and the mixture is sealed and anaerobically fermented at 35° C. for 15 days, and then filtered to obtain the composite extract.

[0048] The preparation method of the microbial agent protective agent is as follows: the following raw materials in mass percentages are mixed evenly, namely, 0.5% CaCl2, 2% chitosan, 0.5% boric acid, 1% PBS buffer solution, and 96% water, and then the pH is adjusted to 7.0 to obtain the protective agent.

[0049] The effective live bacteria count in the composite microbial agent for soil remediation is 3.55 billion CFU / g.

[0050] The preparation method of the composite microbial agent for soil remediation specifically comprises the following steps:

[0051] S1, mixing a liquid jelly-like Bacillus inoculum, a liquid Bacillus megaterium inoculum, and a liquid Bacillus subtilis inoculum in proportion to obtain a composite liquid inoculum;

[0052] S2. Add the composite extract and the microbial agent protective agent into the composite liquid agent and stir evenly to obtain a composite microbial agent for soil remediation.

[0053] Test Example 1: Application of composite microbial agents for soil remediation to the treatment of saline-alkali land around reservoirs

[0054] Soil sample conditions of the test site: soil pH: 8.51; salt content: 15.87 mg / g; organic matter: 0.88%; nitrogen: 660 ppm; potassium: 2.37%; phosphorus: 1058.5 ppm.

[0055] Test crop varieties and names: Wheat: Xindong 17; Corn: 1. Xinsiyu 10, 2. sc-704; Sunflower: Dwarf Big Head.

[0056] There are 12 test plots in this experiment, including 1 control plot and 3 test plots. Each test plot is 1 mu. Each plot is randomly arranged and repeated three times. The distribution of the test plots is shown in Table 1.

[0057] Table 1 Distribution of test sites

[0058] Experimental site 2 Comparison site 2 Test Site 31 Experimental site 3 Test Site 2 Test Site 32 Control site 1 Test Site 3 Experimental site 1 Test Site 23 Test Site 21 Comparison site 3

[0059] The field operation process is as follows:

[0060] 1) Carry out preliminary preparations such as land preparation, land leveling, ridge building, watering and connecting irrigation belts;

[0061] 2) 20 kg of the composite microbial agent for soil remediation prepared in Example 1 was added to each of the test sites 1, 2 and 3, and only 20 kg of clean water was used in the control site;

[0062] 3) After two days, when the crops can be planted in the field, apply powdered organic fertilizer (Hebei Yantui Bioengineering Co., Ltd., organic matter ≥ 45%). The application rate of powdered organic fertilizer in test site 1 is 500 kg, and that in test site 2 is 1000 kg. No powdered organic fertilizer is applied in test site 3 and the control site.

[0063] 4) Watering once more after four days until thoroughly irrigated, and at the same time, 5 kg, 0.5 kg, and 0.5 kg of the composite microbial agent for soil remediation prepared in Example 1 were added to the test plot 1, the test plot 2, and the test plot 3, respectively, while the control plot was not treated;

[0064] 5) Sowing six days later, before sowing, mix the seeds with the composite microbial agent for soil remediation prepared in Example 1 at a dosage of 1 kg / mu, and water the seeds according to the soil moisture after sowing. The specific watering conditions are as follows:

[0065] 1) Water once with micro-sprinkler irrigation on the 3rd day after sowing, and some wheat and sunflower seedlings will emerge; 2) Water once with micro-sprinkler irrigation on the 11th day after sowing; 3) Water once with micro-sprinkler irrigation on the 18th day after sowing; 4) Water once with micro-sprinkler irrigation on the 25th day after sowing, and the amount of watering is determined according to the growth of the plants.

[0066] On the 28th day after sowing, the growth and development of wheat are shown in Table 2.

[0067] Table 2 Wheat growth and development

[0068]

[0069] In addition, the control wheat showed yellow tip and wilting, while the experimental wheat did not show this phenomenon. The growth and development of corn on the 28th day after sowing is shown in Table 3.

[0070] Table 3 Growth and development of corn

[0071]

[0072] On the 24th day after sowing, the growth and development of oil sunflower are shown in Table 4.

[0073] Table 4 Growth and development of oil sunflower

[0074]

[0075] The test results of soil samples before land preparation and after emergence are shown in Tables 5 and 6.

[0076] Table 5 Soil sample test results before land preparation

[0077] Soil sample type Depth(cm) pH Total ion content (g / kg) Soil sample before land preparation 1 0-10cm 8.93 101.7 Soil sample before land preparation 1 10-20cm 8.68 31.3 Soil sample before land preparation 1 20-30cm 8.95 24.1 Soil sample before land preparation 1 30-40cm 8.85 27.0 Soil sample before land preparation 2 0-10cm 8.79 23.2 Soil sample before land preparation 2 10-20cm 8.51 27.1 Soil sample before land preparation 2 20-30cm 8.63 24.1 Soil sample before land preparation 2 30-40cm 8.62 23.1

[0078] Table 6 Test results of soil samples after emergence

[0079]

[0080]

[0081] In summary, under the condition of saving fertilizer and water without washing alkali, pressing salt and applying other fertilizers, the application of the composite microbial agent of the present invention can make saline-alkali land reclaimed in the same year, and crops such as corn, wheat and oil sunflower can be planted in the same year, and they can grow in the same year.

[0082] In addition, it can be seen from the above test data that: the corn and oil sunflower in the control plot can basically not germinate, and the wheat has a phenomenon of retraction after germination; while the plots treated with the composite microbial agent product of the present invention can germinate after sowing, and the crop seedlings will not retract due to salinity after germination. This shows that the composite microbial agent for soil remediation of the present invention has a significant positive effect on plant growth. Specifically, these results show that the composite microbial agent of the present invention improves the microbial ecological environment of the soil, improves the fertility and water retention capacity of the soil, and promotes the healthy growth of plants. In addition, the composite microbial agent may enhance the stress resistance of the plant, so that it can remain healthy under adverse conditions. These factors work together to make the wheat in the test plot perform better than the wheat in the control plot under the same conditions.

[0083] Test Example 2 Effects of composite microbial agents for soil remediation on the growth and fruiting rate of rice seedlings

[0084] Four groups were set up for this test, among which, test one was clean water, test two was the original solution of the composite microbial agent of Example 1 of the present invention, test three was a 10-fold dilution of the composite microbial agent of Example 1, and test four was a 100-fold dilution of the composite microbial agent of Example 1.

[0085] The experiment used seedling trays to grow seedlings, with each treatment area of ​​0.15m 2 100g dry seeds were sown in each seedling tray, and 3 replicates were set. After emergence, the rice seedlings in the seedbed were sprayed with foliar spray once at the 2-leaf 1-heart stage, and the spraying amount was 1kg / mu. After foliar spraying, the plant height, stem diameter, root length, chlorophyll, fresh weight, dry weight and other indicators were investigated on the 14th day, and the results are shown in Table 7.

[0086] Among them, chlorophyll PAS is the ratio of the SPAD values ​​(chlorophyll content measurement values) of leaves at 650nm and 940nm.

[0087] Table 7 Results of physiological indexes of rice seedlings on the 14th day after treatment

[0088]

[0089] As can be seen from Table 7, the group treated with the composite microbial agent of the present invention is significantly better than the control group, and various physiological indicators have been improved. Among them, the treatment group diluted 10 times has the best effect, which proves that the composite microbial agent for soil remediation can be used as a foliar spray fertilizer, and the dilution multiple of the foliar spray is 10 to 100 times.

[0090] Test Example 3 Effect of composite microbial agent for soil remediation on rice

[0091] Experimental crop: rice (Hemeizhan); Experimental site: rice fields at Dafeng Base of Plant Protection Institute of Guangdong Academy of Agricultural Sciences.

[0092] Experimental process: The water planting method is transplanting and sowing seedlings, and then transplanting and planting 28 days later. The tractor is used for rotary tillage. During the second land preparation, 500 kg of base fertilizer and miscellaneous fertilizer and 20 kg of compound fertilizer (compound fertilizer 15-15-15, Hebei Yantui Bioengineering Co., Ltd.) are applied per mu. Conventional herbicides are applied three days after transplanting, 3 kg of urea is applied per mu, and topdressing is applied 5 days after transplanting. 5 kg of urea and 5 kg of compound fertilizer (compound fertilizer 15-15-15, Hebei Yantui Bioengineering Co., Ltd.) are applied 5 days after transplanting. 5 kg of urea and 7.5 kg of potassium chloride are applied during the booting stage. During the whole process, pest and water management are according to conventional rice management.

[0093] The whole test process was repeated 3 times with 4 treatment areas, each with an area of ​​30m 2, each treatment area is randomly arranged. The agents and dosages of each treatment area are shown in Table 8. The method of using the agent in the test is to use a sprayer to spray 44kg / mu evenly after adding water. Spray once 10 days and 25 days after transplanting, and spray the entire planting area twice. The experimental land is clay, with medium fertility, pH value of 6.0, and organic matter content of 2.3%. The test results are shown in Table 9.

[0094] Table 8 Test agents and dosage

[0095]

[0096]

[0097] Table 9 Test results

[0098]

[0099] After observing the leaf color of each group of plants, it was found that the leaf color of treatment area 1 and treatment area 2 was darker than that of treatment area 3, and both were light green, while the leaf color of the control group was yellow-green. In addition, according to the results in Table 9, the composite microbial agent of the present invention has the best growth and yield effects at a dosage of 450 mL / mu, and both are significantly higher than the control group.

[0100] Test Example 4 Application of composite microbial agent for soil remediation on cabbage

[0101] The test crop is Chinese cabbage, the variety is "Jinfeng"; the soil type of the test site is loam, with medium to high fertility, and the test area is 240m 2 The whole test process was repeated 3 times with 4 treatment areas (a water control group and treatment areas with different dosages of the composite microbial agent of Example 1, where the dosage of treatment area 1 was 50 mL / mu, the dosage of treatment area 2 was 100 mL / mu, and the dosage of treatment area 3 was 300 mL / mu). The area of ​​each treatment area was 20 m 2 , plant spacing: 35cm×50cm, with protective rows around, and each treatment area was randomly arranged. The test results are shown in Tables 10 and 11.

[0102] Table 10 Test results (I)

[0103]

[0104] Table 11 Test results (II)

[0105]

[0106] It can be seen from Tables 10 and 11 that the composite microbial agent for soil remediation of the present invention has the best growth effect on Chinese cabbage when applied twice per season at a dosage of 300 mL per mu.

[0107] Test Example 5: Stability Test

[0108] The composite microbial agent for soil remediation of Example 1 was used as an experimental group, and the composite microbial agent without adding the composite extract and the microbial agent protective agent was used as a control to measure the stability of the agent.

[0109] The preparation method of the control group is the same as that of Example 1, except that no composite extract and microbial agent protective agent are added.

[0110] The test method is as follows:

[0111] Equal amounts of the experimental group composite microbial inoculants and the control group composite microbial inoculants were placed in containers of the same specifications, sealed and stored at room temperature at 25°C away from light for 2 years, and the effective live bacteria count of each group of composite microbial inoculants was determined, with 3 parallel tests set up for each group.

[0112] The results showed that the number of effective live bacteria in the experimental group of composite microbial inoculants increased by (16.8±0.6)% compared with the control group.

[0113] Example 2

[0114] The same as Example 1, except that: the composite microbial agent for soil remediation is composed of the following raw materials in percentage by mass:

[0115] Liquid jelly-like Bacillus agent 15%, liquid Bacillus megaterium agent 5%, liquid Bacillus subtilis agent 73%, compound extract 6%, microbial agent protective agent 1%.

[0116] Example 3

[0117] The same as Example 1, except that: the composite microbial agent for soil remediation is composed of the following raw materials in percentage by mass:

[0118] Liquid jelly-like Bacillus agent 5%, liquid Bacillus megaterium agent 15%, liquid Bacillus subtilis agent 67%, compound extract 10%, microbial agent protective agent 3%.

[0119] Example 4

[0120] Same as Example 1, except that the composite extract is composed of the following raw materials in percentage by mass:

[0121] 0.1% of mugwort extract, 0.1% of tea polyphenols, 1% of persimmon extract, 5% of bamboo extract, 12% of coltsfoot extract, 4% of honeysuckle extract, and the balance is water.

[0122] Example 5

[0123] Same as Example 1, except that the composite extract is composed of the following raw materials in percentage by mass:

[0124] 2% of mugwort extract, 1.5% of tea polyphenols, 2% of persimmon extract, 1% of bamboo extract, 1% of coltsfoot extract, 1% of honeysuckle extract, and the balance is water.

[0125] Example 6

[0126] The same as Example 1, except that the microbial agent protective agent is composed of the following raw materials in percentage by mass:

[0127] CaCl2 0.1%, chitosan 3%, boric acid 0.1%, PBS buffer 0.1%, and the balance is water.

[0128] Example 7

[0129] The same as Example 1, except that the microbial agent protective agent is composed of the following raw materials in percentage by mass:

[0130] CaCl2 1.5%, chitosan 1%, boric acid 1.5%, PBS buffer 1.5%, and the balance is water.

[0131] After testing, there was no significant difference between the effects of the composite microbial agent for soil remediation prepared in Examples 2 to 7 and the composite microbial agent for soil remediation prepared in Example 1 (P>0.05).

[0132] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A composite microbial agent for soil remediation, characterized in that: It is composed of the following raw materials in percentage by mass: Liquid jelly-like bacillus agent 5% to 15%, liquid bacillus megaterium agent 5% to 15%, liquid bacillus subtilis agent 60% to 80%, composite extract 6% to 10%, microbial agent protective agent 1% to 3%, the sum of the above raw materials by mass percentage is 100%; The microbial agent protective agent is composed of the following raw materials in percentage by mass: CaCl2 0.1%-1.5%, chitosan 1%-3%, boric acid 0.1%-1.5%, PBS buffer 0.1%-1.5%, and the balance is water.

2. A composite microbial agent for soil remediation according to claim 1, characterized in that: The composite microbial agent for soil remediation comprises the following raw materials in percentage by mass: Liquid jelly-like Bacillus agent 10%, liquid Bacillus megaterium agent 10%, liquid Bacillus subtilis agent 70%, composite extract 8%, microbial agent protective agent 2%.

3. The composite microbial agent for soil remediation according to claim 1, characterized in that: The preparation method of the liquid bacterial agent is as follows: preparing a culture medium, and then inoculating jelly-like bacillus, bacillus megaterium and bacillus subtilis into a seed tank respectively, with an inoculation amount of 0.1% to 0.3%, a culture temperature of 35°C to 37°C, a rotation speed of 50 to 150 rpm, a pressure of 0.04 to 0.05 MPa, and a fermentation time of 4 to 6 hours; then transferring the culture to a fermentation tank respectively, with an inoculation amount of 1 to 3%, a culture temperature of 35°C to 37°C, a rotation speed of 20 to 50 rpm, a pressure of 0.04 to 0.05 MPa, and fermentation for 14 to 26 hours; during the fermentation process, observing the morphology of the bacteria through a microscope, and stopping the fermentation when it is found that the bacteria become shorter and more than 90% of the bacteria form spores, so as to obtain a liquid jelly-like bacillus bacterial agent, a liquid bacillus megaterium bacterial agent or a liquid bacillus subtilis bacterial agent.

4. The composite microbial agent for soil remediation according to claim 1, characterized in that: The composite extract is composed of the following raw materials in percentage by mass: 0.1% to 2% of wormwood extract, 0.1% to 1.5% of tea polyphenols, 1% to 2% of persimmon extract, 1% to 5% of bamboo extract, 1% to 2% of coltsfoot extract, 1% to 4% of honeysuckle extract, and the balance is water.

5. The composite microbial agent for soil remediation according to claim 4, characterized in that: The composite extract is composed of the following raw materials in percentage by mass: 1% wormwood extract, 0.5% tea polyphenols, 1.5% persimmon extract, 3% bamboo extract, 1.5% coltsfoot extract, 2.5% honeysuckle extract, 90% water.

6. The composite microbial agent for soil remediation according to claim 1, characterized in that: The preparation method of the composite extract is as follows: wormwood extract, tea polyphenols, persimmon extract, bamboo extract, coltsfoot extract, honeysuckle extract and water are uniformly mixed in proportion, 10% Bacillus subtilis is inoculated, and after sealed anaerobic fermentation at 33°C to 37°C for 7 to 15 days, the composite extract is filtered to obtain the composite extract.

7. The composite microbial agent for soil remediation according to claim 1, characterized in that: The preparation method of the microbial agent protective agent is as follows: CaCl2, chitosan, boric acid and PBS buffer are uniformly mixed and then the pH is adjusted to 7.

0.

8. The composite microbial agent for soil remediation according to claim 1, characterized in that: The effective live bacteria count in the composite microbial agent for soil remediation is ≥ 1 billion CFU / g.

9. The method for preparing the composite microbial agent for soil remediation according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing a liquid jelly-like Bacillus inoculum, a liquid Bacillus megaterium inoculum, and a liquid Bacillus subtilis inoculum in proportion to obtain a composite liquid inoculum; S2. Add the composite extract and the microbial agent protective agent into the composite liquid agent and stir evenly to obtain a composite microbial agent for soil remediation.

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