Low-temperature in-situ rapid straw decomposition agent and preparation method thereof

Abstract

The invention relates to a low-temperature in-situ rapid straw decomposition agent and a preparation method thereof. The low-temperature in-situ rapid straw decomposition agent comprises trichoderma asperellum, aspergillus niger, bacillus subtilis, trichoderma longibrachiatum, saccharomycetes and trametes versicolor. Trichoderma asperellum, aspergillus niger, bacillus subtilis, trichoderma longibrachiatum, saccharomycetes and trametes versicolor are adopted to construct a compound bacterium system, the trichoderma asperellum and the aspergillus niger are used as main materials, and the bacillus subtilis, the trichoderma longibrachiatum, the saccharomycetes and trametes versicolor are used as auxiliary materials. The straw can be efficiently degraded at a low temperature (less than 15 DEG C), the degradation efficiency is high, and the decomposition is rapid.

Description

Technical Field

[0001] The invention belongs to the technical field of organic material composting agents and relates to a low-temperature in-situ rapid straw composting agent and a preparation method thereof. Background Art

[0002] Crop straw contains a variety of nutrients that can be used for plant and microbial growth, and is an important biomass resource. China is a major agricultural producer with a huge output of crop straw, with an average annual straw output of more than 900 million tons. Among them, rice, corn, and wheat are the main crops with high straw output, and the straw of these three crops accounts for more than 80% of the total straw output. In agricultural production, crop straw is often directly returned to the field for fertilization. Returning straw to the field affects the physical and chemical properties of the soil, providing a good soil environment for crop growth, thereby achieving the effect of increasing crop yields.

[0003] However, the slow degradation of straw under natural conditions poses a serious production obstacle to the growth of the next crop. Using microorganisms with straw degradation function to accelerate straw decomposition and solve the technical problem of returning straw to the field is of great significance to the full utilization of straw resources, the cultivation of farmland fertility and the sustainable development of agriculture.

[0004] Straw degrading bacteria can be divided into high temperature straw degrading bacteria, medium temperature straw degrading bacteria and low temperature straw degrading bacteria according to their optimal degradation temperatures. Low temperature straw degrading bacteria are suitable for low temperature conditions and can make straw decompose quickly at low temperatures.

[0005] Straw is rich in macromolecular substances such as cellulose, hemicellulose, and lignin, and the effect of single-function degradation bacteria is often not ideal. Therefore, it is of great significance to construct a composite bacterial degradation system and develop a technology suitable for rapid decomposition of in-situ straw under low temperature conditions. Summary of the invention

[0006] The invention aims to provide a low-temperature in-situ rapid straw decomposition agent and a preparation method thereof.

[0007] The technical solution adopted by the present invention to achieve its purpose is as follows:

[0008] A low-temperature in-situ rapid straw decomposition agent comprises Trichoderma aculeatus, Aspergillus niger, Bacillus subtilis, Trichoderma longifolia, yeast and Trametes versicolor.

[0009] Furthermore, the Trichoderma acanthoides is activated and cultured until the number of viable bacteria in the Trichoderma acanthoides bacterial solution reaches 2.0×10 8 CFU / mL; the Aspergillus niger is activated and cultured until the number of viable bacteria in the Aspergillus niger liquid reaches 2.0×10 8 CFU / mL; the Bacillus subtilis is activated and cultured until the number of viable bacteria in the Bacillus subtilis liquid reaches 2.0×108 The long-branch Trichoderma is activated and cultured until the number of viable bacteria in the long-branch Trichoderma liquid reaches 2.0×10 8 CFU / mL; the yeast is activated and cultured until the number of viable bacteria in the yeast solution reaches 2.0×10 8 The versicolor Trametes are activated and cultured until the number of viable bacteria in the versicolor Trametes liquid reaches 2.0×10 8 CFU / mL.

[0010] Furthermore, the volume ratio of the Trichoderma spinulosa solution, Aspergillus niger solution, Bacillus subtilis solution, Trichoderma longifolia solution, yeast solution, and Trametes versicolor solution is 3:2.5:1:1:1:1.5.

[0011] A method for preparing a low-temperature in-situ rapid straw decomposition agent comprises the following steps:

[0012] S1. Inoculate Trichoderma spinulosa, Aspergillus niger, and Trichoderma longibrachiatum in LB liquid medium and activate and culture them until the number of viable bacteria reaches 2.0×10 8 CFU / mL, the bacterial solution of Trichoderma acanthosporum, Aspergillus niger and Trichoderma longibrachiatum were obtained;

[0013] S2. Inoculate Bacillus subtilis, yeast, and Trametes versicolor on PDA liquid culture medium and activate and culture them until the number of viable bacteria reaches 2.0×10 8 CFU / mL, obtained Bacillus subtilis solution, yeast solution, and Trametes versicolor solution;

[0014] S3. The above-obtained Trichoderma spinulosa solution, Aspergillus niger solution, Bacillus subtilis solution, Trichoderma longifolia solution, Saccharomyces cerevisiae solution, and Trametes versicolor solution are mixed in a volume ratio of 3:2.5:1:1:1:1:1.5 to obtain a mixed solution.

[0015] Furthermore, the method further comprises the following steps:

[0016] S4. The obtained composite bacterial solution is centrifuged to remove the culture medium, and the bacterial cells obtained after centrifugation are resuspended in physiological saline;

[0017] S5. Dissolve the water-soluble embedding agent with distilled water, sterilize it, add the resuspended microbial suspension in step S4, stir evenly, and dry until the moisture content is less than 10% to obtain a solid composting agent.

[0018] Furthermore, the water-soluble embedding agent comprises 2-4% sodium alginate, 2-5% isolichen polysaccharide and 5-6% maltodextrin in terms of weight to volume ratio.

[0019] Furthermore, the method further comprises dropping the microbial suspension treated with S5 into a calcium chloride solution with a mass concentration of 2-5%, reacting for 20-30 minutes, taking out the suspension, rinsing it with physiological saline, and drying it until the moisture content is less than 10%.

[0020] Furthermore, in step S4, the centrifugal speed is 4000 rpm and the centrifugal time is 10 min.

[0021] Beneficial effects of the present invention:

[0022] The low-temperature in-situ rapid straw decomposition agent of the present invention can efficiently degrade straw at low temperature (<15° C.), has high degradation efficiency and rapid decomposition.

[0023] The present invention adopts Trichoderma aculeatus, Aspergillus niger, Bacillus subtilis, Trichoderma longifolia, yeast and Trametes versicolor to construct a composite bacterial system, with Trichoderma aculeatus and Aspergillus niger as the main components, and Bacillus subtilis, Trichoderma longifolia, yeast and Trametes versicolor as the auxiliary components. The microorganisms in the combination each have different nutrient decomposition capabilities and ecological functions, thereby providing a complementary effect; moreover, the introduction of yeast (Saccharomyces cerevisiae) can increase the energy conversion in the decomposition process, which may provide a better environment for other microorganisms; these microorganisms can jointly increase the organic matter content of the soil and promote the decomposition of straw.

[0024] The present invention can protect the survival rate of the bacteria at a low temperature of about 4°C by using an embedding agent of 2-4% (w / v) sodium alginate, 2-5% (w / v) isolichen polysaccharide and 5-6% (w / v) maltodextrin, thereby improving the storage activity of the bacteria. After further cross-linking with calcium, the survival rate is even higher. Through the embedding technology of the present invention, microorganisms can be effectively protected and utilized, their ability to survive and function in the soil can be enhanced, the effect of applying microorganisms can be significantly improved, and the function of degrading straw can be quickly exerted after application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the low temperature activity curve of the composting agent of the present invention. DETAILED DESCRIPTION

[0026] Trichoderma acanthosporum has the ability to quickly decompose organic matter, can produce a variety of enzymes that degrade cellulose and lignin, and has strong adaptability. Aspergillus niger can promote the degradation of cellulose and hemicellulose, and can also produce organic acids, which helps release nutrients during the degradation process. Bacillus subtilis, as a type of Bacillus, has a strong degradation ability and promotes straw composting. Trichoderma longifolia can decompose organic substances such as cellulose, hemicellulose and lignin in straw into small molecular sugars and other organic substances by secreting enzymes such as cellulase, thereby achieving the degradation of straw. Trametes versicolor is a white rot fungus with a strong ability to decompose lignin, suitable for degrading complex wood materials.

[0027] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the art without making creative work should belong to the scope of protection of the present invention. The raw materials used in the present invention can be purchased on the market.

[0028] Example 1

[0029] A low-temperature in-situ rapid straw decomposition agent (composite bacterial liquid) comprises a volume ratio of 3:2.5:1:1:1:1.5 of Trichoderma spinulosa liquid, Aspergillus niger liquid, Bacillus subtilis liquid, Trichoderma longifolia liquid, yeast liquid, and Trametes versicolor liquid, wherein the number of live bacteria in the Trichoderma spinulosa liquid reaches 2.0×10 8 CFU / mL; the number of viable bacteria in the Aspergillus niger liquid reached 2.0×10 8 CFU / mL; the number of viable bacteria in the Bacillus subtilis liquid reached 2.0×10 8 CFU / mL; the number of viable bacteria in the long-branch Trichoderma liquid reached 2.0×10 8 CFU / mL; the number of live bacteria in the yeast solution reaches 2.0×10 8 CFU / mL; the number of viable bacteria in the color-changing Trametes versicolor liquid reached 2.0×10 8 CFU / mL.

[0030] The low-temperature in-situ rapid straw decomposition agent is prepared by the following method:

[0031] S1. Trichoderma spinulosa, Aspergillus niger, and Trichoderma longibrachiatum were inoculated into LB liquid medium (LB liquid medium was prepared by adding 10 g of peptone, 5 g of yeast extract, and 10 g of NaCl to 950 ml of ddH2O; the pH value was adjusted to 7.0 with 1 M NaOH, the volume was fixed to 1 L, and the medium was sterilized by high pressure at 121°C for 20 min and stored at 4°C) and activated and cultured until the number of viable bacteria reached 2.0 × 10 8 CFU / mL, the bacterial solution of Trichoderma acanthosporum, Aspergillus niger and Trichoderma longibrachiatum were obtained;

[0032] S2. Bacillus subtilis, Saccharomyces cerevisiae, and Trametes versicolor were inoculated on PDA liquid culture medium (PDA liquid culture medium formula: 200 g potato, 20 g glucose, 5 g peptone, 3 g potassium dihydrogen phosphate, 1.5 g magnesium sulfate, 1000 mL water) and activated and cultured until the number of viable bacteria reached 2.0 × 10 8 CFU / mL, obtained Bacillus subtilis solution, yeast solution, and Trametes versicolor solution;

[0033] S3. The above-obtained Trichoderma spinulosa solution, Aspergillus niger solution, Bacillus subtilis solution, Trichoderma longifolia solution, Saccharomyces cerevisiae solution, and Trametes versicolor solution are mixed in a volume ratio of 3:2.5:1:1:1:1:1.5 to obtain a mixed solution.

[0034] Example 2

[0035] A low-temperature in-situ rapid straw decomposition agent (solid composite bacterial agent)

[0036] First, obtain a mixed bacterial solution according to Example 1, and then perform the following operations:

[0037] S4. The obtained composite bacterial solution was centrifuged at a centrifugal rate of 4000 rpm for 10 min, the culture medium was removed, and the bacterial cells obtained after centrifugation were resuspended in physiological saline;

[0038] S5. Dissolve sodium alginate, isolichen polysaccharide and maltodextrin in distilled water to obtain 2-4% (w / v) sodium alginate, 2-5% (w / v) isolichen polysaccharide and 5-6% (w / v) maltodextrin embedding agent. After sterilization, add the resuspended microbial suspension in step S4, stir evenly, and dry until the moisture content is <10% to obtain a solid composting agent.

[0039] Example 3

[0040] A low-temperature in-situ rapid straw decomposition agent (solid composite bacterial agent) is prepared on the basis of Example 2. The microbial suspension resuspended in step S4 is evenly mixed with a water-soluble embedding agent, and then added dropwise to a 4% calcium chloride solution. After reacting for 20 minutes, the mixture is taken out, rinsed with saline, and dried to a moisture content of <10% to obtain a solid decomposition agent.

[0041] Test Example 1

[0042] The compost prepared in Example 2 and Example 3 was evenly spread on the corn stalks at an application rate of 1 kg / mu, turned into the soil, and watered. The average maximum temperature during the test was 16°C, and the temperature difference between day and night was 10°C. After 30 days, the soil was sampled to determine the nitrogen, phosphorus and potassium contents. The results are shown in Table 1.

[0043] Table 1

[0044]

[0045] It can be seen from Table 1 that returning straw directly to the field can improve soil fertility, indicating that returning straw to the field produces degradation. The fertility is further improved by adding the composting agent of the present invention, indicating that adding the composting agent of the present invention can accelerate the degradation of straw and accelerate the release of nutrients.

[0046] Test Example 2

[0047] 2-4% (w / v) sodium alginate was used as an embedding agent as control example 1, 2-4% (w / v) sodium alginate and 5-6% (w / v) maltodextrin were used as embedding agents as control example 2, and the rest of the scheme was the same as that of Example 2. Example 1, Example 2, Example 3, Control example 1, and Control example 2 were placed at 4°C to detect their low-temperature activity, and the number of viable bacteria was detected every 5 days. When testing Example 2, Example 3, Control example 1, and Control example 2, the solid compost was re-dissolved in water. The results are shown in Figure 1 .

[0048] Depend on Figure 1 It can be seen that after being treated with the embedding agent, the bacterial flora is protected, so its activity at low temperatures can be preserved, and the low-temperature survival rate of live bacteria is prolonged.

Claims

1. A low-temperature in-situ rapid straw decomposition agent, characterized in that: These include Trichoderma aculeatus, Aspergillus niger, Bacillus subtilis, Trichoderma longifolia, yeast and Trametes versicolor.

2. A low-temperature in-situ rapid straw decomposition agent according to claim 1, characterized in that: The Trichoderma acanthoides is activated and cultured until the number of live bacteria in the Trichoderma acanthoides bacterial solution reaches 2.0×10 8 CFU / mL; the Aspergillus niger is activated and cultured until the number of viable bacteria in the Aspergillus niger liquid reaches 2.0×10 8 CFU / mL; the Bacillus subtilis is activated and cultured until the number of viable bacteria in the Bacillus subtilis liquid reaches 2.0×10 8 The long-branch Trichoderma is activated and cultured until the number of viable bacteria in the long-branch Trichoderma liquid reaches 2.0×10 8 CFU / mL; the yeast is activated and cultured until the number of viable bacteria in the yeast solution reaches 2.0×10 8 The versicolor Trametes are activated and cultured until the number of viable bacteria in the versicolor Trametes liquid reaches 2.0×10 8 CFU / mL.

3. A low-temperature in-situ rapid straw decomposition agent according to claim 2, characterized in that: The volume ratio of the Trichoderma spinulosa solution, Aspergillus niger solution, Bacillus subtilis solution, Trichoderma longifolia solution, yeast solution and Trametes versicolor solution is 3:2.5:1:1:1:1.

5.

4. A method for preparing a low-temperature in-situ rapid straw decomposition agent, characterized in that: The following steps are involved: S1. Inoculate Trichoderma spinulosa, Aspergillus niger, and Trichoderma longibrachiatum in LB liquid medium and activate and culture them until the number of viable bacteria reaches 2.0×10 8 CFU / mL, the bacterial solution of Trichoderma acanthosporum, Aspergillus niger and Trichoderma longibrachiatum were obtained; S2. Inoculate Bacillus subtilis, yeast, and Trametes versicolor on PDA liquid culture medium and activate and culture them until the number of viable bacteria reaches 2.0×10 8 CFU / mL, obtained Bacillus subtilis solution, Trichoderma longifolia solution, yeast solution, Trametes versicolor solution; S3. The above-obtained Trichoderma spinulosa solution, Aspergillus niger solution, Bacillus subtilis solution, Trichoderma longifolia solution, Saccharomyces cerevisiae solution, and Trametes versicolor solution are mixed in a volume ratio of 3:2.5:1:1:1:1:1.5 to obtain a mixed solution.

5. The method for preparing a low-temperature in-situ rapid straw decomposition agent according to claim 4, characterized in that: The following steps are also included: S4. The obtained composite bacterial solution is centrifuged to remove the culture medium, and the bacterial cells obtained after centrifugation are resuspended in physiological saline; S5. Dissolve the water-soluble embedding agent with distilled water, sterilize it, add the resuspended microbial suspension in step S4, stir evenly, and dry until the moisture content is less than 10% to obtain a solid composting agent.

6. The method for preparing a low-temperature in-situ rapid straw decomposition agent according to claim 5, characterized in that: The water-soluble embedding agent comprises 2-4% sodium alginate, 2-5% isolichen polysaccharide and 5-6% maltodextrin in terms of weight to volume ratio.

7. The method for preparing a low-temperature in-situ rapid straw decomposition agent according to claim 5, characterized in that: The method also includes dropping the microbial suspension treated with S5 into a calcium chloride solution with a mass concentration of 2-5%, reacting for 20-30 minutes, taking it out, rinsing it with physiological saline, and then drying it until the moisture content is less than 10%.

8. The method for preparing a low-temperature in-situ rapid straw decomposition agent according to claim 5, characterized in that: In step S4, the centrifugal speed is 4000 rpm and the centrifugal time is 10 min.

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