Microflora combination for in-situ enrichment of earthworms in soil, culture medium and application

Abstract

The invention discloses a flora combination for in-situ enrichment of earthworms in soil, a culture medium and application of the flora combination, and the flora combination comprises Cupriavidus necator, a bacterial strain YTR-C1 with the preservation number of CGMCC27358, Sinorhizobium sp., a bacterial strain YTR-S1 with the preservation number of CGMCC20681, Mesorhizobium amorphae and a bacterial strain YTR-M3 with the preservation number of CGMCC17532, and the bacterial strain YTR-C1 with the preservation number of CGMCC27358, Sinorhizobium sp., Sinorhizobium sp., Sinorhizobium sp., Sinorhizobium sp., Sinorhizobium sp., Sinorhizobium sp., the flora composition is preserved in China General Microbiological Culture Collection Center on May 16th, 2023, September 18th, 2020 and April 9th, 2019, the flora composition and the culture medium can increase the number of the far-caffeilus in the red soil, field tests find that the effective phosphorus content and the phosphatase activity in the red soil are remarkably increased by adding the far-caffeilus, and the effective phosphorus content and the phosphatase activity of the red soil are remarkably increased by adding the far-caffeilus. The yield and the quality of the corn and the rape are improved.

Description

Technical Field

[0001] The present invention relates to the technical field related to soil earthworm breeding, and in particular to a bacterial community combination, culture medium and application thereof for in situ enrichment of earthworms in soil. Background Art

[0002] In recent years, the beneficial effects of synthetic gut microbiota on host growth, reproduction, and immune function have garnered widespread attention, providing new perspectives and approaches for the development of soil animal enrichment technologies. Soil animals are crucial components of the soil ecosystem, playing a key role in organic matter decomposition, nutrient cycling, and soil structure improvement. However, the growth and reproduction of soil animals are influenced by soil environmental conditions and the microbial community. Research has shown that the introduction of synthetic gut microbiota can significantly improve the growth and reproduction of soil animals. First, synthetic gut microbiota can optimize the nutritional metabolism of soil animals. For example, probiotics can produce digestive enzymes and short-chain fatty acids, helping soil animals more efficiently decompose organic matter and absorb nutrients, thereby promoting their growth and reproduction. Second, synthetic gut microbiota can enhance the immune function of soil animals and reduce the threat posed by pathogens to their health. Synthetic gut microbiota can stimulate the host immune system, promoting the maturation and function of immune cells, thereby improving soil animal resistance to environmental pathogens. Furthermore, synthetic gut microbiota can improve the soil microenvironment and promote the growth of beneficial microorganisms. This balanced microbial community helps maintain the stability of the soil ecosystem, providing a healthier living environment for soil animals. Based on these research results, a method for enriching soil animals using synthetic gut microbiota has been developed, which will significantly improve the growth and reproduction of soil animals. This not only helps enhance the ecological functions of soil animals but also provides a new technical means for agriculture and environmental protection. Therefore, the application of synthetic gut microbiota in soil animal enrichment has broad prospects and is expected to bring significant ecological and economic benefits.

[0003] Earthworms are one of the major functional groups of soil animals. They are numerous and diverse, and are widely distributed in soils across a wide range of habitats. Their feeding activities and excrement (vermicompost) have a significant impact on soil structure and fertility. Earthworms have short generation cycles and are sensitive to environmental changes, making them often used as indicators of soil health and fertility. The ecological role of earthworms lies not only in directly ingesting organic matter, decomposing it, and releasing nutrients, but also in improving soil structure, increasing porosity and aeration through their activities, thereby promoting soil microbial activity. Earthworms occupy a key position in the soil food web, altering the biomass, diversity, and community composition of microorganisms through their activities, while also directly influencing their own adaptability and health. Earthworm-microbe interactions regulate energy transfer and the conversion and storage of carbon, nitrogen, and phosphorus nutrients in soil ecosystems, playing an important role in maintaining the structural stability and functional diversity of the soil food web. Summary of the Invention

[0004] In response to the technical problems and practical needs of developing a fast and efficient in situ earthworm propagation method in the prior art, the present invention provides a bacterial community combination, culture medium and application for in situ enrichment of earthworms in soil. Earthworms release nutrients held in their bodies by feeding on soil microorganisms, thereby promoting plant growth. The earthworm castings produced during the earthworm enrichment process are rich in organic matter and phosphorus. The earthworm castings can not only improve the water holding capacity and aeration of the soil, but also significantly improve the bioavailability of soil phosphorus. In order to alleviate the phosphorus stress of red soil and improve the bioavailability of phosphorus, native earthworms can be enriched in situ from dryland red soil, their culture conditions can be optimized, and earthworms and their earthworm castings can be applied to low-yield dryland red soil in order to increase the red soil phosphatase activity and the content of available phosphorus storage capacity, thereby increasing crop yield and improving quality. The native variety of earthworm, Farblind Earthworm, showed significant effects in this process, significantly improving plant growth and yield through earthworm castings accumulation and soil structure improvement.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a bacterial community combination that promotes the growth, reproduction and immunity of earthworms, which includes one or more of the following strains: Cupriavidus necator (strain YTR-C1), deposited in the General Microbiology Center of China Culture Collection of Microorganisms on May 16, 2023, with a deposit number of CGMCC NO.27358, Sinorhizobium (Sinorhizobium.Sp, strain YTR-S1), deposited in the General Microbiology Center of China Culture Collection of Microorganisms on September 18, 2020, with a deposit number of CGMCC NO.20681, Mesorhizobium (Mesorhizobiumamorphae, strain YTR-M3), deposited in the General Microbiology Center of China Culture Collection of Microorganisms on April 9, 2019, with a deposit number of CGMCC NO.17532.

[0006] Preferably, the earthworm is identified as Amynthas sp.

[0007] Preferably, the bacterial flora originates from the intestines of earthworms.

[0008] Preferably, the bacterial community combination is used to analyze changes in earthworm motor function and immune performance by regulating the expression of earthworm myosin and / or mitogen-activated protein kinase (MAPK).

[0009] The present invention also provides an earthworm culture medium, which includes a bacterial agent and soil, wherein the soil is a mixed culture matrix of red soil, corn straw and decomposed pig manure in a mass ratio of 1.5:1:1.2, and the bacterial agent is a bacterial agent containing the bacterial community combination described in claim 1.

[0010] Preferably, the concentration of the bacterial agent in the culture medium is 10 4 -10 8 Pieces / gram of soil.

[0011] The present invention also provides uses of the bacterial community combination and earthworm culture medium for dissolving phosphate in red soil and / or improving corn yield and quality.

[0012] The present invention also provides an in-situ enrichment method for earthworms in soil, which comprises the following steps: mixing the soil with the above bacterial community combination and / or the earthworm culture medium.

[0013] The in situ enrichment method for earthworms in soil according to claim 8 is characterized in that: the earthworm culture medium is filled into a plastic container with a breathable bottom to a thickness of 40 cm, filled once every ten days, and a 5 cm thick culture matrix is ​​filled each time, and the bacterial agent is evenly sprayed into the culture matrix, the soil moisture is adjusted to 60% to 65% of the field water holding capacity, and cultured in a dark environment under a natural environment at a culture temperature of 12-28°C, and the earthworms are harvested after 60 days.

[0014] The strain screening and earthworm enrichment of the present invention include the following steps:

[0015] (1) Native earthworms and test soil were collected from the experimental station. The bacterial community structure in the earthworm gut and soil was detected by high-throughput sequencing. Key bacteria shared by the gut and soil were identified by network analysis.

[0016] (2) The key bacteria were fed to earthworms in different combinations, and combined with transcriptome analysis, the bacterial community combination with the best effect on promoting the growth and reproduction of earthworms was obtained.

[0017] (3) Different concentrations of optimal bacterial combinations were set to mix with red soil, straw and pig manure to enrich earthworms in situ.

[0018] (4) Apply earthworms and earthworm castings to the experimental plots.

[0019] In the step (2), the best key bacterial combination for promoting the growth, reproduction and immunity of earthworms is Cupriavidus necator, Sinorhizobium sp. and Mesorhizobium umamorphae.

[0020] In step (2), the optimal key bacterial combination significantly increased the survival rate (237.5%) and average fresh weight (46.29%) of earthworms.

[0021] In the step (2), the optimal key bacterial combination increased the expression of myosin (128.71%) and mitogen-activated protein kinase genes (215.71%) in earthworms.

[0022] In the step (2), after screening the best bacterial strain combination, the bacterial strain ratio in the bacterial agent is further set to achieve the optimal bacterial agent addition conditions for promoting earthworm growth.

[0023] In step (3), the inoculation density of adult earthworms is 1.25 kg / m 2 .

[0024] In step (3), the earthworm culture medium is red soil, corn stalks and decomposed pig manure, with a mass ratio of 1.5:1:1.2, and is filled into a plastic container with a breathable bottom to a thickness of 40 cm. The filling is done once every ten days, and each time the culture medium is filled to a thickness of 5 cm. The concentration of the three bacterial agents is set to 10 4 , 10 6 and 10 8 pieces / gram of soil, spray them evenly into the culture medium in sequence, adjust the soil moisture to 60% to 65% of the field water holding capacity, culture in the dark under natural environment, the culture temperature is 12-28℃, and the earthworms are harvested after 60 days.

[0025] In the step (4), the amount of earthworms added is 60g / m 2 The amount of vermicompost added is 3kg / m 2 .

[0026] The far-blind earthworm obtained by the invention is used for dissolving phosphorus in red soil.

[0027] The far-blind earthworm obtained by the invention is used for improving the yield and quality of corn.

[0028] Specifically, in the step (1), 9 collected earthworms were collected, washed and soaked in 25% anhydrous ethanol, and the earthworms stopped twisting. The intestinal tract of the earthworms was dissected to obtain about 2.2g of intestinal contents. 10g of test soil and 2g of intestinal contents were taken for high-throughput sequencing. In the step (2), a combination of one bacterium, two bacteria, and three bacteria was set up, a total of 7 bacterial combination schemes plus a control group without addition. The soil used was in situ sterilized red soil 1kg×3 parallel / treatment, the earthworm variety used was 5 far-blind earthworms×3 parallel / treatment, and the amount of bacterial agent added was 10 6 / gram of soil. A four-week experiment of earthworm inoculation and cultivation was conducted indoors, during which the culture temperature was controlled at 20-25°C, the soil moisture reached 60%-65% of the field water holding capacity, and 20g of sterilized and decomposed pig manure was added once a week to provide a food source for the earthworms. The in-situ enrichment method of earthworms according to claim 1 is characterized in that: in the step (2), the surviving earthworms are collected after the experimental period, and the number of earthworms and fresh weight are counted. After the collected earthworms are cleaned, 3 adult earthworms are randomly selected for each treatment, and 1×1cm 2 The epidermal tissue of the earthworms was quickly frozen in liquid nitrogen and the transcriptome was measured. In step (2), after screening the best bacterial strain combination, the bacterial strain ratio in the bacterial agent was further set to achieve the optimal bacterial agent addition conditions for promoting earthworm growth; in step (3), the inoculation density of adult far-blind earthworms was 1.25 kg / m 2 .

[0029] Beneficial effects:

[0030] This invention is simple to operate, utilizes abundant raw materials, improves the in-situ growth environment of earthworms, enhances the reproductive capacity of earthworms, and improves the quality of the biofertilizer, vermicompost. By introducing earthworms into red soil in farmland, phosphorus availability is increased, promoting increased corn yield and quality. Compared to existing technologies, this invention has the following advantages:

[0031] (1) In situ enrichment of native earthworms in dryland red soil. By adding key microbial agents common to the test red soil and the intestinal tract and agricultural organic waste, the survival rate and reproductive capacity of earthworms in the red soil were enhanced, thereby improving earthworm yield and earthworm castings quality. The earthworms cultured using the technical solution of the present invention grow rapidly, have strong reproductive capacity, and produce high-quality biofertilizer. Furthermore, the in situ earthworm enrichment method has low production costs, simple technology, and is suitable for large-scale promotion.

[0032] (2) The application of the earthworms and earthworm castings to red soil increases the effectiveness of phosphorus in the red soil.

[0033] (3) The application of the earthworms and earthworm castings to red soil increases the absorption and utilization of red soil nutrients by corn, improves corn growth, and significantly increases the yield and quality of corn and rapeseed. The in situ enriched earthworms and earthworm castings of the present invention significantly increase crop yield and improve quality, and are suitable for large-scale use in field crop production areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the far-blind earthworm in red soil;

[0035] Figure 2 Key bacteria for identification;

[0036] Figure 3 The changes of earthworm related indicators after adding different combinations of microbial agents;

[0037] Figure 4 To optimize the changes in earthworm quantity and vermicompost quality under the conditions of microbial agent concentration;

[0038] Figure 5 The yield of corn and rapeseed under the conditions of adding earthworms and vermicompost;

[0039] Table 1 shows the data of earthworm related indicators after adding different combinations of microbial agents;

[0040] Table 2 shows the changes in earthworm-related indicators under different concentrations of bacterial agents. DETAILED DESCRIPTION

[0041] The present invention will be further explained below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and should not and cannot be used to limit the scope of protection of the present invention.

[0042] Example 1 Method for collecting earthworm intestinal contents and identifying key bacteria in test soil

[0043] The earthworms cultivated by the present invention are far-blind earthworms. Figure 1 The biological characteristics of the genus Teleodon are shown below: Oligochaeta, Gastromysidae, genus Teleodon. Body size varies, with numerous setae arranged in an annular pattern on each segment. The annulus is located on segments XIV-XVI and is circular. Males have a pair of pores located on the surface of segment XVIII, occasionally on segment XIX, and lack a copulatory cavity. Females have one, occasionally two, pores located on segment XIV. Spermatheca pores are generally paired, but may be single or absent, located between intersegments 4, 5, 6, 7, 8, and 9. The gizzard is located between septa 7, 8, and 8, and lacks an esophageal pouch. The cecum originates on or near segment XXVII. The testes are located between segments X and XI, or within segment XI. Ovaries are paired and located on segment XIII. Spermatheca pores are generally paired, but may be single or absent, with a nephric layer occasionally present on the spermathecal duct.

[0044] The earthworm intestinal contents and test soil were collected as follows:

[0045] 1. The field experiment was conducted at the Yingtan National Field Scientific Observation and Research Station for Agro-Ecosystems in Jiangxi Province (116°55'E, 28°13'N). The experimental area has a mid-subtropical monsoon climate, with an average annual temperature of 17.8°C, an average annual precipitation of 1795 mm, and a frost-free period of 262 days.

[0046] 2. Nine earthworms were hand-picked from the experimental plot, washed with sterile water, and placed in a plastic insulated box lined with ice packs to cool for 5 minutes. The earthworms were then placed in a 30% ethanol solution at 0°C until they stopped moving. The earthworms were removed, washed with sterile water to remove any sticky tissue, and then blotted dry with sterile cotton cloth. After pretreatment, the abdominal intestine of the earthworms was incised using a sterile scalpel blade from 0.5 cm below the anus to the anus. The incised intestinal epidermis was fixed externally, and the intestinal contents were scraped with a small spoon and collected in a 5 mL centrifuge tube. 0.5 mL of PBS buffer was added and the tube was immediately refrigerated at -80°C. The collected intestinal contents and the test soil were subjected to high-throughput sequencing using primers 515F (5'-GTGCCAGCMGCCGCGCGGGTAA-3') and 907R (5'-CCGTCAATTCCTTTGAGTTT-3') to determine the microbial composition.

[0047] 3. Through high-throughput sequencing results, the operational taxonomic units (OTUs) of the earthworm intestinal and test soil bacterial communities were obtained, and network analysis was performed on them. Based on the network modules, two important node characteristics were analyzed: intra-module connectivity (Zi) and inter-module connectivity (Pi). According to the topological characteristics of the nodes, they can be divided into four types, including: module hubs, which are nodes with high connectivity within the module, and Z i >2.5 and P i <0.62; connection hub, a node with high connectivity between two modules, Z i <2.5 and P i >0.62; network hub, a node with high connectivity in the entire network, Z i >2.5 and P i >0.62; peripheral nodes, nodes that do not have high connectivity within or between modules, Z i <2.5 and P i <0.62. Except for peripheral nodes, the other three types of nodes are classified as key nodes, i.e. key microorganisms. Figure 2As shown, the three key bacteria with higher abundance were identified as Cupriavidus necator (strain YTR-C1): network center; Sinorhizobium sp. (strain YTR-S1): connection node; and Mesorhizobium amorphae (strain YTR-M3): module center. Cupriavidus necator, strain YTR-C1, was deposited in the General Microorganism Center of China Culture Collection Administration Committee on May 16, 2023, with the accession number CGMCC27358, Sinorhizobium sp., strain YTR-S1, was deposited in the General Microorganism Center of China Culture Collection Administration Committee on September 18, 2020, with the accession number: CGMCC20681, Mesorhizobium amorphae, strain YTR-M3, was deposited in the General Microorganism Center of China Culture Collection Administration Committee on April 9, 2019, with the accession number: CGMCC17532.

[0048] Example 2 Method for Obtaining the Optimal Bacterial Agent Combination for In-situ Culture of Earthworms

[0049] B1: Cupriavidus necator (strain YTR-C1);

[0050] B2: Sinorhizobium sp. (strain YTR-S1);

[0051] B3: Mesorhizobium amorphae (strain YTR-M3).

[0052] BS: B1, B2 and B3, the mixing ratio is 1:1:1.

[0053] Based on the identified key bacteria, set up a control group and 7 treatment groups as follows:

[0054] 1. Select the three key bacterial species mentioned above and dilute them by 10 5 Then, the cells were inoculated in LB medium to obtain single bacterial colonies.

[0055] 2. Use a sterile inoculating loop to scrape three bacterial colonies and place them into the prepared 20mL liquid LB medium in sequence. Place them in a 25℃ constant temperature shaker for 24 hours of incubation. After the incubation, dilute each bacterial culture medium by 10 2 , 10 3 , 10 4 , 10 5 , 106 After fold increase, OD was measured by microplate reader. 600 value.

[0056] 3. Select healthy adult earthworms weighing 5±0.5g, wash them with sterile water, and place them on moist filter paper in a dark box for 12 hours of intestinal cleansing. After complete intestinal cleansing, wash the earthworms again for use. Set up a combination of one bacterium (B1; B2; B3) and two bacteria (B1 and B2; B1 and B3; B2 and B3), and three bacteria (B1 and B2 and B3). The mixing ratio between the strains is 1:1, with a total of 7 bacterial combination schemes and 1 control group (CK) without added bacteria. The test soil is in situ sterilized red soil. Each treatment is set up with 1kg×3 parallels / treatment, 5 earthworms×3 parallels / treatment, and the amount of bacterial agent added is 10 6 / gram of soil, earthworms after cleansing their intestines were placed in the in-situ sterilized red soil, and bacteria were evenly sprayed on the soil surface. The culture cycle was 4 weeks, the culture temperature was controlled at 20-25℃, the soil moisture reached 60%-65% of the field water holding capacity, and 20g of sterilized and decomposed pig manure was added once a week to provide a food source for the earthworms.

[0057] 4. After the experimental period, the surviving earthworms in the different treatment groups were collected and the number of earthworms and fresh weight were counted. The collected earthworms were washed with sterile water and immediately placed in an insulated box filled with ice to cool for 5 minutes to reduce the earthworms' activity. Three adult earthworms were randomly selected for each treatment, and a 1×1 cm 2 The epidermal tissue was quickly frozen in liquid nitrogen and the transcriptome was measured.

[0058] 5. If Figure 3 As shown in Table 1, bacteria B3 and mixed flora increased the survival rate of earthworms. Bacteria B2 and mixed flora increased the average fresh weight of earthworms. Bacteria B3 and the three bacterial combinations increased the expression of earthworm myosin. Bacteria B1 and mixed flora increased the expression of MAPK in earthworms. Bacteria B1 mainly stimulated the expression of MAPK in earthworms, bacteria B2 promoted earthworm growth, and bacteria B3 promoted earthworm muscle activity and increased survival rate. Among the three bacterial combinations of B1&B2&B3, the earthworm survival rate reached the highest of 60%, and the average fresh weight was the highest at 3.47g. The gene expression levels of myosin and MAPK were the highest, at 824.38 and 3.91 respectively. Therefore, the bacterial agent BS was determined to be the best bacterial agent combination for in situ enrichment of earthworms.

[0059]

[0060]

[0061] Table 1 (Example 2)

[0062] Example 3 Optimizing the Effect of the Ratio of Bacteria in the Optimal Bacterial Agent Combination BS on Earthworm Growth

[0063] The abundance ratio of bacteria B1, B2, and B3 in the earthworm intestine in the field experiment was approximately 4:3:5;

[0064] The abundance ratio of bacteria B1, B2, and B3 in the field experiment soil was approximately 4:6:3;

[0065] The abundance ratio of bacteria B1, B2, and B3 in the earthworm intestine and soil in the field experiment was approximately 8:9:8;

[0066] T1: B1&B2&B3, the mixing ratio is 1:1:1;

[0067] T2: B1&B2&B3, the mixing ratio is 4:3:5;

[0068] T3: B1&B2&B3, the mixing ratio is 4:6:3;

[0069] T4: B1&B2&B3, the mixing ratio is 8:9:8;

[0070] According to the steps of Example 2, a control group T0 (no bacteria added) and four treatment groups T1, T2, T3 and T4 were set up. As shown in Table 2, T1, T2, T3 and T4 all increased the survival rate, average fresh weight and expression of myosin and MAPK of earthworms. Among them, the survival rate of earthworms in the T3 treatment group was the highest, reaching 93.33%, and the average fresh weight was the highest, reaching 4.68g. The gene expression levels of myosin and MAPK were the highest, at 1568.26 and 10.56 respectively. Therefore, the bacterial agent T3 was determined to be the optimal bacterial agent combination ratio for in situ enrichment of earthworms.

[0071]

[0072]

[0073] Table 2 (Example 3)

[0074] Example 4 Effect of the optimal bacterial agent concentration mixed with the culture medium on earthworm enrichment

[0075] 1. Culture medium components:

[0076] The physical and chemical properties of the in situ sterilized red soil tested were as follows: pH 5.83, organic carbon 3.32 g / kg, total nitrogen 0.41 g / kg, total phosphorus 0.31 g / kg, alkaline-hydrolyzable nitrogen 18.64 mg / kg, available phosphorus 2.4 mg / kg, and available potassium 52.67 mg / kg.

[0077] Physical and chemical properties of decomposed pig manure: total nitrogen 334.05g / kg, total phosphorus 16.02g / kg.

[0078] Culture medium: in situ sterilized red soil, corn straw and decomposed pig manure, with a mass ratio of 1.5:1:1.2.

[0079] 2. BS concentration gradient: C0: 0 per gram of soil; C1: 10 4 / gram soil; C2: 10 6 / gram soil; C3: 10 8 Soil refers to the culture medium.

[0080] 3. The density of adult earthworms is 1.25kg / m 2 .

[0081] 4. Customize a light-proof plastic container with a hole for ventilation at the bottom and a lid with a small hole for ventilation at the top. The size is 60×60×100cm. Fill the container with culture medium to a depth of 40cm. Fill it once every ten days, filling 5cm of culture medium each time. Set the concentration of the inoculum to 0, 10 4 , 10 7 and 10 10 pieces / gram of soil, spray them evenly into the culture medium in sequence, adjust the soil moisture to 60% to 65% of the field water holding capacity, culture in the dark under natural environment, the culture temperature is 12-28℃, and the earthworms are harvested after 60 days.

[0082] 5. If Figure 4 As shown in the data, under the treatment conditions of BS with C2 concentration, the fresh weight of earthworms per mu reached a maximum of 259 kg; the average number of days for larvae to grow to maturity was as low as 35 days; the average weight of earthworms was as high as 5.53 g; the earthworm castings yield was as high as 4465.33 kg / mu; the physical and chemical properties of earthworm castings were as follows: pH 6.3, organic carbon 32%, total nitrogen 2.3%, total phosphorus 2.1%, and total potassium 1.9%, all of which were higher than those of the C0, C1, and C3 treatment groups.

[0083] Example 5 Effects of earthworm and earthworm castings application on soil phosphorus availability and crop yield

[0084] 1. Earthworms: The intestines of the earthworms were cleansed for 24 hours, and then treated with BS at a C2 concentration for 7 days to obtain earthworms stimulated with key bacteria.

[0085] 2. Experimental setup: no application (CK); application of earthworms (E); application of vermicompost (C); application of earthworms and vermicompost (EC). The experimental plot area is 20m 2 , each treatment had 3 replicates.

[0086] 3. Variety and planting method: The corn seed is Suyu No. 29, which has excellent characteristics such as high disease resistance, drought resistance and high temperature resistance. The sowing rate is 20kg / hm2 2The row spacing is 20cm×40cm, the sowing depth is 10-15cm, and the planting density is 68,000 plants / hm2. 2 .

[0087] 4. The earthworm stocking density is 60g / m for adult far-blind earthworms. 2 The amount of vermicompost added is 3kg / m 2 .

[0088] 5. The field experiment was carried out until the corn matured. The rhizosphere soil of corn was collected and the phosphatase activity and available phosphorus content of each treatment were measured. The results showed that the phosphatase activity of the treatment (EC) with the addition of earthworms and earthworm castings increased by 68.45%, 40.34%, and 39.68% compared with the CK, E and C treatment groups, respectively, and the available phosphorus content increased by 18.69%, 16.23%, and 15.31% compared with the CK, E and C treatment groups, respectively.

[0089] 6. Field trials were conducted until maize and rapeseed reached maturity. Maize and rapeseed plants were harvested and their grain biomass, leaf soluble sugars, soluble protein, and leaf indoleacetic acid content were measured. Results showed that the addition of earthworms and vermicompost (EC) to the corn and rapeseed treatments increased grain yield by 26.21%, 10.23%, and 9.57%, and 38.22%, 11.50%, and 11.23%, respectively, compared with the control, E, and C treatments. Leaf soluble sugar content increased by 23.26%, 13.21%, and 11.20%, respectively, compared with the control, E, and C treatments. Soluble protein content increased by 29.28%, 14.37%, and 14.23%, respectively, compared with the control, E, and C treatments. Leaf indoleacetic acid content increased by 33.45%, 17.46%, and 15.49%, respectively, compared with the control, E, and C treatments.

[0090] Finally, the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of the present invention. It should be noted that those skilled in the art may make improvements and modifications to the technical solution of the present invention without departing from the principles of the present invention, and all such modifications and improvements should be considered within the scope of protection established by the present invention.

Claims

1. A bacterial community that promotes the growth, reproduction and immunity of earthworms, characterized by: Including Sinorhizobium sp., strain YTR-S1, deposited in the General Microbiology Center of China Culture Collection Administration on September 18, 2020, with the deposit number: CGMCC No.20681.

2. The bacterial flora for promoting growth, reproduction and immunity of earthworms according to claim 1, characterized in that: Also included is Cupriavidus necator, strain YTR-C1, deposited in the General Microbiology Center of China Culture Collection Administration on May 16, 2023, with the deposit number CGMCC No. 27358; Or Mesorhizobium amorphae, strain YTR-M3, was deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms on April 9, 2019, with the accession number: CGMCC No.17532.

3. The bacterial flora for promoting growth, reproduction and immunity of earthworms according to claim 1, characterized in that: The earthworm was identified as Amynthas sp.

4. The bacterial flora for promoting growth, reproduction and immunity of earthworms according to claim 1, characterized in that: The bacterial flora originates from the intestinal tract of earthworms.

5. An earthworm culture medium, characterized in that: The culture medium includes a bacterial agent and soil, wherein the soil is a mixed culture medium of red soil, corn straw and decomposed pig manure in a mass ratio of 1.5:1:1.2, and the bacterial agent is a bacterial agent containing the bacterial community described in claim 1.

6. The earthworm culture medium according to claim 5, characterized in that: The concentration of the bacterial agent in the culture medium is 10 4 -10 8 Pieces / gram of soil.

7. Use of the bacterial consortium according to claim 1 and the earthworm culture medium according to claim 5 for dissolving phosphate in red soil and / or improving corn yield and quality.

8. A method for in-situ enrichment of earthworms in soil, characterized by: The following steps are involved: The soil can be mixed with the bacterial community described in claim 1 and / or the earthworm culture medium described in claim 5.

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