A corn stalk decomposing agent product and a preparation method thereof

Abstract

This invention belongs to the field of microbial inoculant technology and discloses a corn stalk decomposing agent product and its preparation method. The decomposing agent is composed of microbial inoculants, enzyme preparations, nutrient adjuvants, and a modified carrier in specific weight proportions. The microbial inoculants are a compound of Bacillus subtilis, Trichoderma viride, and Aspergillus niger; the enzyme preparation is a complex of cellulase, xylanase, and laccase; the nutrient adjuvant is a mixture of urea, sucrose, and potassium dihydrogen phosphate; and the carrier is an alkali-modified complex of wheat bran and straw powder. The preparation method includes preparing each microbial inoculant separately, alkali-modifying the carrier, and mixing all components. This invention also discloses the application method of this decomposing agent in corn stalk decomposition. This product achieves rapid, efficient, and thorough decomposition of corn stalks through the synergistic effect of multiple components, and the preparation process is stable, the product has a long shelf life, and it is suitable for large-scale production and field application.

Description

Technical Field

[0001] This invention belongs to the field of microbial inoculant technology, specifically relating to a corn stalk decomposing agent product and its preparation method. Background Technology

[0002] In the field of agricultural production and waste resource utilization, the efficient decomposition of straw is a key link in realizing nutrient recycling and returning to the field, improving soil fertility, and avoiding environmental pollution. As a major agricultural waste, corn straw has a complex composition, high degree of lignification, and a large carbon-nitrogen ratio. It decomposes slowly in natural environments, so it usually relies on microbial decomposition agents to accelerate its decomposition and transformation.

[0003] Current mainstream microbial decomposition technologies have several limitations, including: single-strain preparations (such as simple cellulose-degrading bacteria) have limited functions and struggle to overcome the lignin barrier, leading to incomplete decomposition and long cycles; while simple compound microbial agents, if improperly matched with different strains, are prone to antagonism and lack necessary nutrient initiation and physical carrier support, resulting in low survival rates and unstable efficacy of the microbial community in harsh straw environments. Furthermore, existing technologies suffer from a core contradiction: increasing decomposition speed often relies on high doses of exogenous chemical catalysts or acid / alkali pretreatment, which, while improving efficiency in the short term, easily causes secondary soil pollution and inhibits native soil microbial communities; while relying entirely on natural fermentation results in excessively long cycles, failing to meet agricultural time requirements. Summary of the Invention

[0004] To address the above problems, this invention discloses a corn stalk decomposing agent product and its preparation method.

[0005] The objective of this invention is achieved through the following technical solution.

[0006] A corn stalk decomposing agent product is composed of the following raw materials in parts by weight:

[0007] 15-25 parts of microbial inoculant, wherein the microbial inoculant is composed of Bacillus subtilis in a weight ratio of (1-3):(1-2):1. Bacillus subtilis green Trichoderma Trichoderma viride and Aspergillus niger Aspergillus niger composition;

[0008] 5-10 parts of enzyme preparation, wherein the enzyme preparation is composed of cellulase, xylanase and laccase in a weight ratio of (3-5):(2-4):1;

[0009] 3-8 parts of nutritional supplement, wherein the nutritional supplement is a mixture of urea, sucrose and potassium dihydrogen phosphate in a weight ratio of (2-4):1:1;

[0010] 60-80 parts of modified carrier; the modified carrier is obtained by mixing wheat bran and straw powder in a weight ratio of (1-2):1, soaking in a 2-5 wt% sodium hydroxide solution for 1-2 hours, and then filtering and drying until the water content is less than 10 wt%.

[0011] Furthermore, in the aforementioned corn stalk decomposing agent product, the effective viable count of Bacillus subtilis in the microbial agent is ≥2.0 × 10⁻⁶. 10 CFU / g, effective spore count of *Trichoderma viride* ≥ 1.0 × 10⁻⁶ 10 CFU / g, effective spore count of Aspergillus niger ≥ 1.0 × 10⁻⁶ 10 CFU / g.

[0012] Furthermore, in the aforementioned corn stalk decomposing agent product, the cellulase activity is ≥10000 U / g, the xylanase activity is ≥8000 U / g, and the laccase activity is ≥500 U / g.

[0013] This invention also discloses a method for preparing the above-mentioned corn stalk decomposing agent product, comprising the following steps:

[0014] (1) Preparation of microbial inoculants: Bacillus subtilis, Trichoderma viride and Aspergillus niger were fermented and cultured separately, and then the obtained Bacillus subtilis fermentation broth, Trichoderma viride spore powder and Aspergillus niger spore powder were mixed to obtain microbial inoculants;

[0015] (2) Preparation of modified carrier: Mix wheat bran and straw powder in proportion, soak in 2-5wt% sodium hydroxide solution at 50-60°C for 1-2 hours, filter and dry at 60-70°C until the water content is less than 10wt% to obtain modified carrier;

[0016] (3) Mixing: According to the weight proportions, the microbial agent, enzyme preparation, and nutrient additives obtained in step (1) and the modified carrier obtained in step (2) are placed in a mixer and mixed thoroughly.

[0017] (4) Packaging: Seal the well-mixed product into a package to obtain the corn stalk decomposing agent product.

[0018] Furthermore, in the above method, the Bacillus subtilis described in step (1) is fermented in LB liquid medium at a fermentation temperature of 35-37°C for 36-48 hours.

[0019] Furthermore, in the above method, the *Trichoderma viride* and *Aspergillus niger* mentioned in step (1) are fermented on a wheat bran solid culture medium at a fermentation temperature of 28-30°C for 5-7 days.

[0020] Furthermore, in the above method, the mixing in step (3) is carried out under light-protected conditions, and the mixing time is 30-60 minutes.

[0021] This invention also discloses a method for decomposing corn stalks using the above-mentioned corn stalk decomposing agent product, comprising the following steps:

[0022] a. Straw pretreatment: Crush the corn stalks to a length of 2-5cm;

[0023] b. Preparation of bacterial solution: Mix the decomposing agent product with water at a weight ratio of 1:(50-100), and add 0.1-0.2wt% of Tween 80 as a dispersant, and stir evenly to prepare bacterial solution;

[0024] c. Composting and fermentation: Mix the crushed corn stalks with the bacterial solution prepared in step b, and spray sterile water to adjust the moisture content of the stalks to 60-70 wt%. Then build a pile and cover it with breathable and heat-insulating material for fermentation.

[0025] d. Process control: During fermentation, the pile is turned over when the temperature at the center of the pile rises above 65°C. The entire decomposition cycle is 20-30 days.

[0026] Furthermore, in step c of the above application method, an aeration pipe is inserted into the pile body during pile construction to promote aerobic fermentation.

[0027] Compared with existing technologies, the present invention has the following advantages and beneficial effects:

[0028] 1. High decomposition efficiency: The product of this invention uses microbial agents and enzyme preparations in synergy to achieve rapid step-by-step degradation of straw cellulose, hemicellulose and lignin, effectively shortening the decomposition cycle.

[0029] 2. Fast start-up and stable effect: The nutrient adjuvant in the formula of this invention provides initial nutrition for microorganisms, solving the problem of delayed start-up caused by the high carbon-nitrogen ratio of straw; the modified carrier optimizes the water retention and microenvironment of the product, ensuring high survival rate and long-lasting activity of the microbial agent in storage and field application.

[0030] 3. Strong environmental adaptability: Test examples show that the product of this invention can maintain good decomposition activity at both room temperature and lower temperatures, and has a wide range of applications.

[0031] 4. Safety and environmental protection: This invention does not introduce chemical pollutants during the decomposition process, and the final product is thoroughly decomposed, non-toxic and harmless to plants, and can realize the harmless and resource-based recycling of agricultural waste. Attached Figure Description

[0032] Figure 1 Comparison of cellulose degradation rates (%) in Test Example 1;

[0033] Figure 2 The effect of the decomposition product extract on wheat germination (germination rate) in Test Example 5.

[0034] Figure 3 The effect of the decomposition product extract on wheat germination in Test Example 5 (average root length (cm)). Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention. All raw materials (including strains, etc., are commercially available products) used in the embodiments of this invention are commercially available. The Bacillus subtilis used in the embodiments of this invention (…) Bacillus subtilis Purchased from Shanghai Yubo Biotechnology Co., Ltd., product number: WB800N Bacillus subtilis; Trichoderma viride ( Trichoderma viride Purchased from Shanghai Enzyme Research Biotechnology Co., Ltd., product number: Trichoderma viride CGMCC3.2942; Aspergillus niger ( Aspergillus niger Purchased from Shanghai Beinuo Biotechnology Co., Ltd., product number: CMCC 98003.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0037] Example 1

[0038] 1. Preparation of microbial inoculants:

[0039] Bacillus subtilis inoculum: Fermented on LB liquid medium at 37°C for 36 hours, the cells were collected by centrifugation, mixed with sterilized wheat bran, and dried to obtain a viable count of 2.5 × 10⁻⁶. 10 CFU / g of bacterial agent.

[0040] Green Trichoderma inoculant: Fermented on a wheat bran solid culture medium at 28°C for 6 days, then dried and pulverized to obtain a spore count of 1.2 × 10⁻⁶. 10 CFU / g of bacterial agent.

[0041] Aspergillus niger inoculum: Fermented on a wheat bran solid culture medium at 28°C for 6 days, then dried and pulverized to obtain a spore count of 1.1 × 10⁻⁶. 10 CFU / g of bacterial agent.

[0042] The above three microbial agents are mixed in a weight ratio of 2:1.5:1 to obtain a microbial agent.

[0043] 2. Preparation of modified carrier: Mix wheat bran and straw powder at a weight ratio of 1.5:1, soak in 3wt% sodium hydroxide solution at 55°C for 1.5 hours, filter and dry at 65°C to a moisture content of 8wt%.

[0044] 3. Preparation of the decomposing agent product: Mix according to the following weight proportions:

[0045] Microbial inoculant: 20 parts

[0046] Enzyme preparation: 7 portions (where the weight ratio of cellulase:xylanase:laccase = 3:3:1, and the enzyme activities are 10000 U / g, 8000 U / g, and 500 U / g, respectively).

[0047] Nutritional supplement: 5 parts (weight ratio of urea: sucrose: potassium dihydrogen phosphate = 3:1:1)

[0048] Modified carrier: 68 parts

[0049] Mix for 45 minutes in the dark, then seal and package.

[0050] Example 2

[0051] The difference from Example 1 is that the microbial inoculant is 15 parts, the enzyme preparation is 5 parts, the nutrient aid is 3 parts, and the modified carrier is 77 parts. The weight ratio of the inoculant (Bacillus subtilis: Trichoderma viride: Aspergillus niger) is 1:1:1.

[0052] Example 3

[0053] The difference from Example 1 is that the microbial inoculant is 25 parts, the enzyme preparation is 10 parts, the nutrient aid is 8 parts, and the modified carrier is 57 parts. The weight ratio of the inoculant (Bacillus subtilis: Trichoderma viride: Aspergillus niger) is 3:2:1.

[0054] Example 4

[0055] The difference from Example 1 is that the alkali treatment concentration of the modified carrier is 2wt%, and the soaking time is 1 hour.

[0056] Example 5

[0057] The difference from Example 1 is that the alkali treatment concentration of the modified carrier is 5 wt%, and the soaking time is 2 hours.

[0058] Comparative Example 1

[0059] The difference from Example 1 is that the microbial agent used is only Bacillus subtilis, and the dosage is 20 parts. The other components and preparation process remain unchanged.

[0060] Comparative Example 2

[0061] The difference from Example 1 is that no enzyme preparation was added. Seven parts by weight of the enzyme preparation were replaced with an equal amount of modified carrier.

[0062] Comparative Example 3

[0063] The difference from Example 1 is that no nutritional supplements are added. Five parts by weight of the nutritional supplements are replaced with an equal amount of modified carrier.

[0064] Comparative Example 4

[0065] The difference from Example 1 is that an unmodified carrier was used. That is, bran and straw powder were directly mixed at a weight ratio of 1.5:1 without alkali treatment.

[0066] Test Example 1

[0067] Straw decomposition efficiency comparison experiment

[0068] Objective: To verify the decomposition efficiency of the complete formulation on corn stalks under standard conditions.

[0069] method:

[0070] Test materials: Products of Examples 1-5 and Comparative Examples 1-4.

[0071] Experimental setup: 1000g of dry corn stalks, 2-5cm in length, were weighed for each group. Various decomposing agents were added at a ratio of 1wt% of the dry stalk weight, and sterile water was sprayed simultaneously to adjust the initial moisture content of the material to 65wt%.

[0072] Fermentation process: Build a pile (approximately 50cm high) in a greenhouse at an ambient temperature of 25±2°C, and cover it with breathable burlap. Turn the pile every 7 days to replenish oxygen.

[0073] Testing indicators:

[0074] Total weight loss (decomposition rate): On day 30, all stockpile material was dried to constant weight at 65°C, and the percentage of dry matter loss was calculated. Total weight loss (%) = [(initial dry weight - final dry weight) / initial dry weight] × 100%.

[0075] Cellulose residue: The cellulose content in the material before and after fermentation was determined by the nitric acid-ethanol method, and the degradation percentage was calculated.

[0076] The results are shown in Table 1 and... Figure 1 .

[0077]

[0078] As shown in the table above, Examples 1, 3, and 5 exhibited the best decomposition effects, with total weight loss exceeding 60% and cellulose degradation exceeding 67%. Example 3 (high bacterial enzyme ratio) showed the best results. Comparative Example 1 (single bacterial agent) showed the worst results, indicating a synergistic effect of the compound bacterial agent. The decomposition efficiencies of Comparative Examples 2 (no enzyme) and 3 (no nutrients) were significantly lower than those of Example 1, demonstrating that the rapid initiation of the enzyme preparation and the promotion of bacterial reproduction by the nutrient adjuvant are indispensable. Although the effect of Comparative Example 4 (unmodified carrier) was better than the other comparative examples, it was significantly worse than all the examples, proving that the carrier modification in this invention has a stable promoting effect on maintaining a long-term and efficient decomposition process by improving the microenvironment.

[0079] Test Example 2

[0080] Monitoring of dynamic changes in fermentation pile temperature

[0081] Objective: To evaluate the ability of different formulations to initiate fermentation and maintain a high temperature period.

[0082] method:

[0083] Test materials: Product of Example 1, and products of Comparative Examples 1, 2, 3, and 4.

[0084] Experimental setup: The reactor was built using the same method as in Test Example 1. A digital thermometer probe was inserted at the center of the reactor, and the temperature was recorded every 12 hours for 21 consecutive days.

[0085] Testing indicators:

[0086] Time to reach 55°C: Measures the speed of fermentation initiation.

[0087] Duration of high temperature: The total duration of time the temperature is above 50°C. The longer the high temperature period, the better the decomposition and harmlessness effect.

[0088] The results are shown in Table 2.

[0089]

[0090] The data in the table above shows that Example 1 exhibited the fastest start-up speed (reaching the high-temperature period in 36 hours) and the longest sustained high-temperature period, likely due to the rapid synergistic effect of bacteria, enzymes, and nutrients, which quickly decomposed organic matter and released heat. In contrast, Comparative Example 1 (single bacterial agent) showed slow start-up, a low maximum temperature, and a short high-temperature period, failing to effectively decompose the organism. Comparative Example 2 (without enzymes) and Comparative Example 3 (without nutrients) showed significantly inhibited start-up speed and high-temperature duration. Comparative Example 4 (unmodified carrier) had moderate start-up and maximum temperature, but its high-temperature duration was shorter than that of Example 1, indicating that the modified carrier plays a crucial role in maintaining the pile structure, retaining water and gas, and thus extending the microbial activity cycle.

[0091] Test Example 3

[0092] Dynamic monitoring of key enzyme activities during fermentation

[0093] Objective: To investigate the actual changes in enzyme activity generated within the pile after the application of the decomposing agent.

[0094] method:

[0095] Test materials: Product of Example 1, product of Comparative Example 2 (enzyme-free).

[0096] Experimental setup: The heap was built using the same method as in Test Example 1. Samples were taken on days 3, 7, 14, and 21.

[0097] Detection indicators: Cellulase and xylanase activities in the pile samples were determined using a kit method.

[0098] The results are shown in Table 3.

[0099]

[0100] As can be seen from the table above, in the early stage of fermentation (day 3), the enzyme activity of Example 1 was much higher than that of Comparative Example 2. This is because the exogenously added enzyme preparation in the product of Example 1 achieved rapid start-up. On day 7, the enzyme activity of Example 1 reached its peak, at which point the exogenous enzyme and the enzyme produced by the endogenous microorganisms worked together. In contrast, the enzyme activity of Comparative Example 2 depended entirely on the slow production by the microorganisms, and therefore remained lower than that of Example 1. This result indicates that the exogenous addition of enzyme preparations not only provides initial motive force but may also stimulate the microbial community to produce more endogenous enzymes.

[0101] Test Example 4

[0102] The effect of carrier modification on product storage stability

[0103] Objective: To verify the effect of carrier modification on the viable bacterial survival rate of the preservative product during storage.

[0104] method:

[0105] Test materials: Product of Example 1 (modified carrier), product of Comparative Example 4 (unmodified carrier).

[0106] Experimental setup: Both products were sealed and stored in a 37°C constant temperature incubator for accelerated aging for 30 days (equivalent to approximately 6 months of room temperature storage). Samples were taken for testing on day 0 and day 30.

[0107] Testing indicators: The total number of viable bacteria in the product was determined using the plate count method.

[0108] The results are shown in Table 4.

[0109]

[0110] Table analysis: After 30 days of accelerated storage, the viable cell survival rate of the product in Example 1 using the modified carrier was as high as 82.8%, significantly higher than that of the product in Comparative Example 4 using the unmodified carrier (64.5%). Alkali modification treatment resulted in a more numerous and stable microporous structure on the carrier, providing better physical protection for the bacteria. Its optimized water absorption and moisture retention properties also maintained a more suitable microenvironment for microbial dormancy within the packaging, effectively reducing the rate of bacterial death during storage.

[0111] Test Example 5

[0112] Ecotoxicity assessment of decomposition products on seed germination

[0113] Objective: To evaluate whether the straw products decomposed using the product of this invention are safe for plants and whether they have potential ecotoxicity.

[0114] Test materials: The final decomposition products of Examples 1 and 3 (representing highly efficient decomposition), and the final decomposition product of Comparative Example 1 (representing incomplete decomposition). Undecomposed straw was used as a negative control, and commercially decomposed straw was used as a positive control.

[0115] Experimental setup: Each decomposition product was extracted with deionized water at a ratio of 1:10 (weight:volume) for 24 hours, and the extract was filtered. Wheat seed germination was conducted using a standard germination chamber. Twenty plump wheat seeds were placed in each petri dish, and 5 mL of the corresponding extract was added. After culturing in a 25°C dark incubator for 3 days, the germination rate was recorded; after 7 days, the root length of the seedlings was measured.

[0116] Detection indicators: seed germination rate, seedling root length (root length inhibition is a sensitive indicator of ecotoxicity).

[0117] The results are shown in Table 5 and Figure 2 and Figure 3 .

[0118]

[0119] As shown in the table, the extracts from the products of Examples 1 and 3, after decomposition, showed no significant difference in germination rate and root length of wheat seeds compared to the control group consisting of commercially decomposed straw and deionized water. This indicates that the decomposition was thorough and complete, and the products were safe and harmless. However, the extracts from Comparative Example 1 (single microbial agent) and undecomposed straw significantly inhibited wheat root growth, suggesting the possible presence of small-molecule organic acids, phenols, and other inhibitory substances resulting from incomplete decomposition. Therefore, the products of this invention can achieve complete straw decomposition, and the final products have no inhibitory effect on plant growth, exhibiting high ecological safety and can be directly used for returning to the field or as a seedling substrate.

[0120] Test Example 6

[0121] Corrosion adaptability test under different ambient temperatures

[0122] Objective: To test the adaptability and decomposition efficiency of the decomposing agent at lower ambient temperatures.

[0123] method:

[0124] Test materials: Product of Example 1 and product of Comparative Example 1 (single bacterial agent).

[0125] Experimental setup: Simulating the low-temperature environment of early spring or late autumn, straw was piled up (small scale, 500g straw) in a 15°C constant temperature incubator, with other conditions the same as in Test Example 1. Example 1 at 25°C was used as a control.

[0126] Detection indicator: Total weight loss rate on day 35.

[0127] The results are shown in Table 6.

[0128]

[0129] Analysis showed that the decomposition efficiency of all groups decreased at a low temperature of 15°C, which is an inevitable result of the slowdown in microbial metabolism. However, Example 1 still achieved a weight loss rate of 38.5% at low temperature, significantly higher than the 18.2% of Comparative Example 1. This indicates that the compatibility of the strains (such as strains that may be adapted to low temperatures) in the compound microbial agent of this invention, as well as the synergy of enzyme preparations and nutrient adjuvants, jointly enhance the functional resilience of the system under adverse temperatures, allowing the decomposition process to continue at low temperatures rather than completely stop. Therefore, the decomposition agent product of this invention has good adaptability to environmental temperature, especially maintaining relatively high decomposition activity under low temperature conditions, thus broadening its practical application time window.

[0130] In Test Example 1 (Decomposition Efficiency), one-way ANOVA and post-hoc multiple comparisons (such as Tukey's HSD test) confirmed that the product of this invention could achieve a total straw weight loss rate of 58%-64% and a cellulose degradation rate of 65%-70% within 30 days. The differences compared to the comparative groups were statistically significant (p<0.05), indicating that the formulation of this invention has a significant advantage in decomposition efficiency. Test Example 2 (Temperature Dynamics) showed that the time to reach 55°C and the duration of high temperature in the example group differed significantly from the comparative groups (p<0.05), proving that the product of this invention can quickly initiate fermentation (reaching 55°C in 36 hours) and maintain high temperature for a long time. Test Example 3 (Enzyme Activity) repeated measures ANOVA showed that the addition of exogenous enzyme preparations significantly improved the early-stage degradation enzyme activity in the compost pile (p<0.01), and the enzyme activity of the example group at each time point was significantly higher than that of the enzyme-free comparative group. Test Example 4 (Storage Stability): t-test analysis showed that the viable bacterial survival rate of the modified carrier group (Example 1) exceeded 82% after accelerated storage, a significant difference compared to the unmodified carrier group (Comparative Example 4) (p<0.01), indicating that carrier modification significantly improved the product's storage stability. Test Example 5 (Ecotoxicity): One-way ANOVA compared germination rate and root length data. The effect of the decomposition product extract on wheat seed germination rate and root length was not significantly different from the deionized water control group (p>0.05), indicating high product safety and no ecotoxicity. Test Example 6 (Low Temperature Adaptability): Two-way ANOVA (temperature × treatment) showed that at 15°C, the decomposition efficiency of Example 1 was significantly higher than that of Comparative Example 1 (p<0.05), and there was a significant interaction between temperature and treatment, proving that the product of this invention can maintain effective decomposition activity under low temperature conditions and has strong adaptability.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of the present invention, or equivalent structural or procedural transformations made using the content of the present invention specification, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of the present invention patent.

Claims

1. A method for preparing a corn stalk decomposing agent product, characterized in that, It consists of the following raw materials in parts by weight: 15-25 parts of microbial inoculant, wherein the microbial inoculant is composed of Bacillus subtilis in a weight ratio of (1-3):(1-2):

1. green Trichoderma and Aspergillus niger composition; 5-10 parts of enzyme preparation, wherein the enzyme preparation is composed of cellulase, xylanase and laccase in a weight ratio of (3-5):(2-4):1; 3-8 parts of nutritional supplement, wherein the nutritional supplement is a mixture of urea, sucrose and potassium dihydrogen phosphate in a weight ratio of (2-4):1:1; 60-80 parts of modified carrier; the modified carrier is obtained by mixing wheat bran and straw powder in a weight ratio of (1-2):1, soaking in a 2-5wt% sodium hydroxide solution for 1-2 hours, and then filtering and drying until the water content is less than 10%; The preparation steps are as follows: (1) Preparation of microbial inoculants: Bacillus subtilis, Trichoderma viride and Aspergillus niger were fermented and cultured separately, and then the obtained Bacillus subtilis fermentation broth, Trichoderma viride spore powder and Aspergillus niger spore powder were mixed to obtain microbial inoculants; (2) Preparation of modified carrier: Mix wheat bran and straw powder in proportion, soak in 2-5wt% sodium hydroxide solution at 50-60℃ for 1-2 hours, filter and dry at 60-70℃ until the water content is less than 10% to obtain modified carrier; (3) Mixing: According to the weight proportions, the microbial agent, enzyme preparation, and nutrient additives obtained in step (1) and the modified carrier obtained in step (2) are placed in a mixer and mixed thoroughly. (4) Packaging: The mixed product is sealed and packaged to obtain the corn stalk decomposing agent product.

2. The method for preparing the corn stalk decomposing agent product according to claim 1, characterized in that, The effective viable count of Bacillus subtilis in the microbial agent is ≥2.0 × 10⁻⁶. 10 CFU / g, effective spore count of *Trichoderma viride* ≥ 1.0 × 10⁻⁶ 10 CFU / g, effective spore count of Aspergillus niger ≥ 1.0 × 10⁻⁶ 10 CFU / g.

3. The method for preparing the corn stalk decomposing agent product according to claim 1, characterized in that, The cellulase activity is ≥10000 U / g, the xylanase activity is ≥8000 U / g, and the laccase activity is ≥500 U / g.

4. The method as described in claim 1, characterized in that, The Bacillus subtilis described in step (1) is fermented in LB liquid medium at a temperature of 35-37℃ for 36-48 hours.

5. The method as described in claim 1, characterized in that, The *Trichoderma viride* and *Aspergillus niger* mentioned in step (1) are fermented on a wheat bran solid culture medium at a temperature of 28-30℃ for 5-7 days.

6. The method as described in claim 1, characterized in that, The mixing in step (3) is carried out under light-protected conditions, and the mixing time is 30-60 minutes.

7. A method for decomposing corn stalks using the corn stalk decomposing agent product as described in any one of claims 1-3, characterized in that, Includes the following steps: a. Straw pretreatment: Crush the corn stalks to a length of 2-5cm; b. Preparation of bacterial solution: Mix the decomposing agent product with water at a weight ratio of 1:(50-100), and add 0.1-0.2wt% of Tween 80 as a dispersant, and stir evenly to prepare bacterial solution; c. Composting and fermentation: Mix the crushed corn stalks with the bacterial solution prepared in step b, and spray sterile water to adjust the moisture content of the stalks to 60-70 wt%. Then build a pile and cover it with breathable and heat-insulating material for fermentation. d. Process control: During fermentation, the pile is turned over when the temperature at the center of the pile rises above 65°C. The entire decomposition cycle is 20-30 days.

8. The method as described in claim 7, characterized in that, In step c, aeration pipes are inserted into the pile during pile construction to promote aerobic fermentation.

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