Microbial complex microbial inoculant and application thereof in mulching planting mode

Abstract

The present application relates to a kind of microbial complex microbial inoculant and its application in covering planting mode, belong to microbial technical field.The microbial synthetic flora of the present application includes bacillus subtilis JZ23081 and bacillus velezensis JZ23083, and the proportion of the effective viable count of two strains is 1:1;With the effective viable count of composite microbial inoculant prepared from this synthetic flora ≥5.0×10 8 / mL.The present application also provides the application of the synthetic flora and composite microbial inoculant in corn covering planting, and provides the product of promoting corn growth, the product of improving soil nutrient conversion rate.The composite microbial inoculant can significantly promote corn growth at seedling stage, improve soil nutrient conversion rate and microbial activity, effectively solve the problem of slow straw decomposition, low ground temperature, late corn emergence, low emergence rate, poor seedling growth and other problems in northern early spring covering planting, realize the synergistic effect of corn seedling and soil improvement, especially suitable for spring corn production in thin layer black soil area, and has important practical significance for agricultural quality and efficiency and ecological protection.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a microbial compound inoculant and its application in mulch planting. Background Technology

[0002] Corn stalk mulching is a commonly used soil fertilization method in current agricultural production. This technology, by covering the soil surface with corn stalks after harvest, achieves multiple benefits, including stabilizing the topsoil structure, increasing soil nutrients, and reducing agricultural production costs. Unlike stalk mulching, crop mulching represents an advanced stage of conservation tillage. Introducing legume mulch crops into conservation tillage systems offers the core advantage of improving soil nitrogen supply through biological nitrogen fixation and increasing organic matter to improve soil nutrient cycling.

[0003] However, in early spring sowing in northern regions, due to climatic conditions, straw decomposes slowly in the soil, making it difficult to achieve the expected soil fertility and nutrient supply effects in the short term. Furthermore, there are limitations such as the asynchronous release of nutrients from crop residues and crop demand. Under conditions of low temperatures and insufficient soil nutrient supply, seed germination is delayed, affecting seed emergence rate and seedling root development, which in turn affects the plant's absorption of water and nutrients.

[0004] To mitigate the adverse effects of low temperatures on spring maize seed germination and emergence, current main measures include mulching, seed priming treatment, and sowing date adjustment. Seed priming treatments often employ osmosis regulators, plant growth regulators, chemical fungicides, or single nutrient preparations. While these can improve seed emergence rates to some extent, their functions are relatively limited, acting only on the surface of seeds or seedlings and failing to improve the rhizosphere soil microecological environment. This is especially true in mulched planting models, where it is difficult to achieve a synergistic effect of robust seedling growth and soil improvement. Summary of the Invention

[0005] Purpose of the invention: To provide a microbial synthetic flora and a microbial compound agent, and further to provide the application of the above-mentioned synthetic flora or compound agent in the mulch planting mode, so as to solve the above-mentioned problems existing in the prior art.

[0006] Based on conservation tillage using straw mulch and crop mulch, the inventors developed a microbial synthetic flora by screening and compounding two functional live microorganisms: Bacillus subtilis (… Bacillus subtilis JZ23081 and Bacillus belesiensis ( Bacillus velezensis JZ23083.

[0007] Specifically, the present invention is achieved through the following scheme: In a first aspect, the present invention provides a synthetic microbial community comprising the following microbial strains: Bacillus subtilis ( Bacillus subtilisJZ23081 was deposited on October 23, 2025 at the China General Microbiological Culture Collection Center, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC No. 36304. Bacillus belesiensis ( Bacillus velezensis JZ23083 was deposited on October 23, 2025, at the China General Microbiological Culture Collection Center (CGMCC), No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC No. 36306.

[0008] The effective viable count ratio of Bacillus subtilis JZ23081 and Bacillus belyss JZ23083 in the synthetic bacterial community is 1:1.

[0009] In a second aspect, the present invention provides a microbial compound agent comprising the synthetic microbial community first proposed.

[0010] The effective viable bacteria count of the compound microbial agent is ≥5.0×10⁻⁶. 8 / mL.

[0011] In a third aspect, the present invention provides the application of the synthetic microbial community proposed in the first aspect or the compound microbial agent proposed in the second aspect in crop cultivation.

[0012] Preferably, the crop planting mode is a cover planting mode.

[0013] Preferably, the crop is corn.

[0014] Preferably, the synthetic microbial community or compound microbial agent is used to promote the growth of maize plants.

[0015] Preferably, the synthetic microbial community or compound microbial agent is used to improve soil nutrient conversion rate.

[0016] In a fourth aspect, the present invention provides a product for promoting corn growth, comprising the synthetic microbial community proposed in the first aspect or the compound microbial agent proposed in the second aspect.

[0017] In a fifth aspect, the present invention provides a product for improving soil nutrient conversion rate, comprising the synthetic microbial community proposed in the first aspect or the compound microbial agent proposed in the second aspect.

[0018] In a sixth aspect, the present invention provides a method for promoting maize growth through mulching, comprising the following steps: S1. The straw mulching treatment uses a corn combine harvester to harvest mature corn. After the corn is harvested, the straw is crushed and returned to the field. Before sowing, a straw row-collecting machine is used to collect the straw into rows and place it in empty rows. The cover crop treatment uses a corn combine harvester to harvest mature corn. After the corn is harvested, the stalks are baled and removed from the field. When the corn is sown in the spring, the cover crop is planted in the empty rows at the same time. S2, sown in the spring of the following year, corn adopts a two-to-one spacing planting pattern, with a row spacing of 57-114cm, that is, two rows are planted with one row left empty. The narrow row of 57cm is used as a seedling strip, and the empty row of 114cm is used to place corn stalks or plant cover crops. S3, at the time of sowing, mix the seeds with the compound microbial agent mentioned in the second aspect or add it next to the seeds; the amount of compound microbial agent added is 2 kg / mu at the maximum application rate; other field management is the same as conventional planting.

[0019] Beneficial effects: This invention relates to a microbial compound inoculant and its application in mulch planting: The compound microbial agent showed a significant synergistic effect between Bacillus subtilis JZ23081 and Bacillus belyssus JZ23083. Compared with the single microbial agent and the blank control, it could significantly increase the plant height, stem diameter, plant fresh weight and root dry weight of maize seedlings, promote seedling root development, enhance the plant's ability to absorb water and nutrients, solve the problems of delayed seed germination and weak seedling growth under low temperature conditions, and lay the foundation for high yield of maize in the later stage. Compound microbial agents can effectively activate soil microbial communities, accelerate the decomposition of soil organic matter, significantly increase the content of soil organic matter, available phosphorus and available potassium, and at the same time improve the levels of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN), improve the current situation of low soil nutrient utilization efficiency and unbalanced microbial community structure in thin black soil areas, and achieve efficient conversion and fixation of soil nutrients. The compound microbial agent, applied to the early growth stage (seedling stage) of corn, can effectively alleviate the problems of low soil temperature in early spring in northern regions, slow straw decomposition, and asynchronous release of residual nutrients with crop demand. It can significantly improve the growth of corn seedlings under both straw mulching and uncovered modes, making up for the shortcomings of traditional seed treatment measures that only act on the plant surface and cannot improve the rhizosphere microecology.

[0020] Therefore, the compound microbial agent involved in this invention has a significant effect on improving the growth of maize and soil quality in black soil areas. It can maintain a high soil activation and nutrient conversion rate under low temperature conditions, has strong versatility, and is environmentally friendly. It solves the problems of low soil microbial activity, slow straw decomposition, and delayed nutrient release under low temperature conditions. It has important application value for rapidly improving black soil fertility, utilizing straw resources, and increasing green maize yield. Attached Figure Description

[0021] Figure 1 This is a comparison of maize seedling height in different treatment groups during the pot experiment of Example 1 of the present invention; Figure 2 This is a comparison of the stem diameter of maize seedlings in different treatment groups during the pot experiment of Example 1 of the present invention; Figure 3 This is a comparison of the fresh weight of maize seedlings in different treatment groups during the pot experiment of Example 1 of the present invention. Figure 4 This is a comparison of the root dry weight of maize seedlings in different treatment groups during the pot experiment of Example 1 of the present invention; Figure 5 This is a comparison of soil organic matter content in different treatment groups during the corn seedling stage in a pot experiment of Example 1 of the present invention; Figure 6 This is a comparison of the available phosphorus content in the soil during the seedling stage of maize in different treatment groups during a pot experiment of Example 1 of the present invention; Figure 7 This is a comparison of the available potassium content in the soil of maize seedlings in different treatment groups during the pot experiment of Example 1 of the present invention; Figure 8 This is a comparison of soil microbial biomass carbon in different treatment groups during the seedling and grain-filling stages of maize in a field experiment of Example 2 of the present invention; Figure 9 This is a comparison of soil microbial biomass nitrogen in different treatment groups during the seedling and grain-filling stages of maize in the field experiment of Example 2 of the present invention.

[0022] Information on the preservation of biological materials: Bacillus subtilis ( Bacillus subtilis JZ23081 was deposited on October 23, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences; accession number: CGMCC No. 36304; status: live.

[0023] Bacillus belesiensis ( Bacillus velezensis JZ23083 was deposited on October 23, 2025, at the China General Microbiological Culture Collection Center (CGMCC), No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences; accession number: CGMCC No. 36306; status: live. Detailed Implementation

[0024] This invention discloses a microbial compound inoculant and its application in mulch planting. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired result. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0025] Example 1: Pot experiment to verify the effect of compound microbial inoculants on promoting seedling growth and soil fertility.

[0026] In this embodiment, in-situ soil samples were collected from thin-layer black soil fields in Changtu County, Liaoning Province, for an indoor pot experiment. Four treatment groups were set up: a blank control (CK), Bacillus subtilis inoculant treatment (T1), Bacillus vesiculosus inoculant treatment (T3), and a combination of Bacillus subtilis and Bacillus vesiculosus inoculants (T5). Appropriate inoculant suspensions were quantitatively added during the maize seedling stage, and relevant indicators were measured.

[0027] Results and Analysis (1) Promoting effect on maize growth like Figure 1-4 As shown, compared with the blank control (CK), all treatments with added microbial agents significantly improved the plant height, stem diameter, fresh weight, and root dry weight of maize seedlings. Among them, the growth-promoting effect of the compound microbial agent treatment group (T5) was better than that of the single microbial agent treatment group, indicating that there was a significant synergistic growth-promoting effect between the two strains.

[0028] (2) Enhancement of soil nutrient transformation like Figure 5-7 As shown, none of the single microbial agent treatments achieved significant improvement in soil nutrients: the Bacillus subtilis inoculant treatment group (T1) reduced the content of soil organic matter, available phosphorus, and available potassium compared with the blank control (CK); the Bacillus vesiculosus inoculant treatment (T3) did not significantly improve soil organic matter and available phosphorus, and there was no statistical difference compared with the blank control (CK), but the Bacillus vesiculosus inoculant treatment (T3) significantly increased the content of available potassium in the soil compared with the blank control (CK).

[0029] Compared with the blank control (CK) and each single microbial agent treatment group (T1, T3), the compound microbial agent treatment group (T5) showed a significant effect on improving soil nutrient status.

[0030] Specifically, the combination of Bacillus subtilis JZ23081 and Bacillus belyssus JZ23083 exhibits a significant synergistic effect, which can significantly increase the content of soil organic matter, available phosphorus, and available potassium. This proves that the compound microbial agent of the present invention can effectively activate soil microbial activity, accelerate the transformation and retention of soil nutrients through the synergistic effect between strains, and enhance the soil nutrient supply capacity.

[0031] Pot experiments have confirmed that the compound microbial agent of this invention can not only effectively promote the early growth of corn plants, but also the combination of compound microbial agents shows synergistic advantages. At the same time, it can drive the soil carbon and nitrogen cycle by activating the activity of soil microorganisms, and comprehensively and synergistically improve the soil nutrient conversion capacity.

[0032] Example 2: Field validation of compound microbial agents under different mulching patterns.

[0033] Test location: Liangzhongqiao Town, Changtu County, Tieling City, Liaoning Province (42.74°N, 123.86°E) Sowing time: May 13, 2025 The field trial included an uncovered control group and a two-to-one open corn planting pattern. There were two treatments: corn straw mulching and corn-leguminous crop mulching. Each group had one microbial agent addition plot, and each plot was 5m long and 5m wide.

[0034] Six treatments were set up: (1) Uncovered blank control (CK); (2) Uncovered + microbial agent (MCK); (3) Straw mulch (ST); (4) Straw mulch + microbial agent (MST); (5) Leguminous mulch (CC); (6) Leguminous mulch + microbial agent (MCC).

[0035] Soil samples were collected from 0-20 cm depth during the corn seedling and grain-filling stages, and the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were measured for the six treatment groups.

[0036] Results and Analysis like Figure 8-9 As shown, the effects of the compound microbial agent of this invention on soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) under different cover patterns vary significantly at different growth stages of maize.

[0037] (1) Seedling stage effect: Under uncovered conditions (CK and MCK), the soil MBC and MBN contents of the MCK group with added compound microbial agent were significantly increased, and were the highest values ​​among all treatments. This indicates that in soils lacking fresh organic material input, the compound microbial agent of this invention can independently activate the soil microbial community, significantly increase soil microbial biomass, promote the conversion of available nitrogen to microbial nitrogen, and effectively reduce the risk of nitrogen loss in the early stage of crop growth.

[0038] Under straw return conditions (ST and MST), the soil MBC in the MST group with added compound microbial agent increased by 27% compared to the ST group, while the MBN content showed no significant difference. This indicates that, based on straw return, the compound microbial agent can further synergistically promote the decomposition and transformation of straw by microorganisms, thereby further enhancing soil microbial activity.

[0039] Under leguminous cover conditions (CC and MCC), there were no significant differences in the contents of MBC and MBN between the two soil groups. This indicates that the strong stimulating effect of leguminous cover itself had already brought microbial activity to its peak, which was significantly higher than that of the uncovered control (CK). Under this background, the inoculant did not show any additional incremental stimulation, but it was able to synergistically maintain the level of microbial activity.

[0040] (2) Grain-filling stage effect: Unlike the seedling stage, the soil MBC and MBN contents of all treatments decreased significantly to the level of the blank control CK; among them, there was no significant difference in MBC among the treatments, while the MBN contents of the straw mulch and legume mulch treatments were relatively high. This indicates that straw and legume mulch treatments can provide a continuous input of organic carbon source to the soil, and therefore can still show a significant nitrogen transformation advantage in the later stage of crop growth.

[0041] The main effect of the compound microbial inoculant of this invention on increasing soil microbial biomass occurs in the early stage of crop growth (seedling stage), which is precisely the key stage for solving problems such as "low soil temperature in spring and slow initiation of straw decomposition". Furthermore, the inoculant shows significant effects under both uncovered and straw-covered conditions, and exhibits synergistic maintenance under legume-covered conditions. In addition, the difference in microbial biomass stimulated by the inoculant is not significant in the later growth stage (grain-filling stage), which is consistent with the general rule that the effect of exogenous input weakens as crop growth progresses, highlighting the value of this inoculant in addressing early growth limiting factors.

[0042] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A microbial compound inoculant, characterized in that, It consists of the following microbial strains: Bacillus subtilis JZ23081 was deposited on October 23, 2025 at the China General Microbiological Culture Collection Center, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC No. 36304. Bacillus velezensis JZ23083 was deposited on October 23, 2025 at the China General Microbiological Culture Collection Center, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC No. 36306. The effective live bacteria ratio of Bacillus subtilis JZ23081 and Bacillus vesiculosus JZ23083 in the compound microbial agent is 1:

1. The effective viable count of the compound microbial agent is ≥5.0×10⁻⁶. 8 / mL.

2. The application of the microbial compound inoculant according to claim 1 in crop cultivation.

3. The application of the microbial compound inoculant according to claim 1 in crop cultivation, characterized in that, The crop is corn, and the crop planting method is a cover cropping method.

4. The application of the microbial compound inoculant according to claim 1 in crop cultivation, characterized in that, The aforementioned microbial compound inoculant is used to promote corn growth.

5. The application of the microbial compound inoculant according to claim 1 in crop cultivation, characterized in that, The aforementioned microbial compound inoculant is used to improve soil nutrient conversion rate.

6. A product that promotes corn growth, characterized in that, Includes the microbial compound inoculant as described in claim 1.

7. A product for improving soil nutrient conversion rate, characterized in that, Includes the microbial compound inoculant as described in claim 1.

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