Compound microbial inoculant for promoting plant growth, preparation method and application thereof

Abstract

The application discloses a compound microbial inoculant for promoting plant growth and a preparation method and application thereof. The compound microbial inoculant is prepared by mixing a biological stimulant and a Trichoderma harzianum microbial inoculant. The biological stimulant can promote the growth of plants and the activity of the Trichoderma harzianum microbial inoculant, and increase the yield of crops. The compound microbial inoculant prepared by combining various biological stimulants and microbial inoculants can simultaneously play the functions of soil improvement, auxiliary nutrient absorption and yield increase of crops, can reduce the use amount of chemical fertilizers in agricultural production, can save cost, is convenient to prepare, is simple to use, and has the advantages of safety, high efficiency and environmental protection.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological fertilizer, and particularly relates to a compound microbial agent for promoting plant growth and a preparation method and application thereof. BACKGROUND

[0002] In agricultural production, traditional chemical fertilizers are easy to destroy the balance of soil nutrients and have adverse effects on the environment. In recent years, biological stimulants are a new type of fertilizer that is focused on development in the agricultural industry. Biological stimulants mainly include humic acid, amino acid, seaweed extract, inorganic salt, chitin and chitosan derivatives, and many other types. Unlike fertilizers, biological stimulants are not nutrients themselves. They play an active role in plant growth and flowering by mechanisms such as assisting nutrient absorption, enhancing resistance, and promoting root growth. They can improve the physiological and chemical state of plants, promote root growth, assist nutrient absorption, and maintain other mechanisms to promote plant production.

[0003] Microorganisms widely exist in nature and are closely related to plant growth. Using microorganisms to improve soil nutrients and increase crop yields is of great significance to maintaining the balance of the ecological system.

[0004] Trichoderma harzianum is a common fungus that is widely used in agriculture and biotechnology. It has strong biological control ability, plant growth promotion, promotion of soil ecosystem function, and degradation of organic pollutants. At present, Trichoderma harzianum agents have been widely used as an effective measure to increase the absorption of nutrients by plants, promote plant growth, and reduce the use of chemical fertilizers. However, due to the influence of soil type and application method, single-strain Trichoderma harzianum agents cannot fully exert their growth-promoting effect, limiting the application of Trichoderma harzianum. In addition, current biological stimulants can only indirectly affect plants, with slow and targeted effects. Therefore, developing an organic-inorganic-microbial combined compound microbial agent to promote nutrient absorption and growth of plants and reduce the use of chemical fertilizers has become an inevitable trend for sustainable agricultural development. SUMMARY

[0005] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0007] Therefore, the present application aims at overcoming the deficiencies in the prior art and providing a composite microbial agent for promoting plant growth.

[0008] To solve the above technical problems, the present application provides a composite microbial agent for promoting plant growth, characterized in that it comprises the following components: a biological stimulant and a solid microbial agent; the weight ratio of the biological stimulant to the solid microbial agent is 35-45:55-65.

[0009] As a preferred scheme of the composite microbial agent, the biological stimulant is composed of kelp extract, amino acid, humic acid, magnesium sulfate, potassium sulfate and EDTA iron sodium.

[0010] As a preferred scheme of the composite microbial agent, the mass ratio of the kelp extract, amino acid, humic acid, magnesium sulfate, potassium sulfate and EDTA iron sodium is 16:16:3:4:4:0.1.

[0011] As a preferred scheme of the composite microbial agent, the raw material of the kelp extract is 50% kelp polysaccharide concentrated powder; the humic acid is one or more of mineral source fulvic acid, biochemical fulvic acid and double-source fulvic acid; and the amino acid is amino acid raw powder.

[0012] As a preferred scheme of the composite microbial agent, the solid microbial agent is prepared from Trichoderma harzianum, and the preparation method comprises the following steps: preparing spore liquid from the strain Trichoderma harzianum, and adding the spore liquid into a solid fermentation medium to prepare the solid Trichoderma harzianum microbial agent.

[0013] As a preferred scheme of the composite microbial agent, the effective bacteria number in the Trichoderma harzianum solid fermentation product is 200 million / g.

[0014] Still another object of the present application is to provide a preparation method of the composite microbial agent for promoting plant growth, which overcomes the deficiencies in the prior art.

[0015] The biological stimulant and the solid microbial agent are respectively crushed and sieved.

[0016] The sieved biological stimulant and solid microbial agent are thoroughly mixed to obtain a solid mixture.

[0017] The solid mixture is granulated, dried, sieved and packaged to obtain the composite microbial agent.

[0018] As a preferred scheme of the preparation method, the mesh number of the sieving is 20-30.

[0019] Another object of the present application is to overcome the deficiencies in the prior art and provide an application of a composite microbial agent for promoting plant growth, which is characterized in that: the composite microbial agent is used in the form of seed dressing, root dipping, mixed sowing and mixed application at the time of sowing; and the composite microbial agent is used in the form of broadcasting at the time of crop transplanting.

[0020] As a preferred scheme of the application, the composite microbial agent is applied in an amount of 1-3 kg per mu of field for high-fertility soil and in an amount of 4-6 kg per mu of field for low-fertility soil.

[0021] The present application has the following beneficial effects:

[0022] The composite microbial agent prepared by combining various biological stimulants with Trichoderma harzianum can simultaneously play the functions of soil improvement, auxiliary nutrient absorption and crop yield improvement, can reduce the use amount of chemical fertilizers in agricultural production, saves cost, is convenient to prepare, simple to apply, and has the advantages of safety, high efficiency and environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0024] Figure 1 Application effect diagram of the composite microbial agent on centipede grass.

[0025] Figure 2 Application effect diagram of the composite microbial agent on sudangrass. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific implementation manner of the present application will be described in detail in the following with reference to the embodiment of the specification.

[0027] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0028] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent of or selected from other embodiments.

[0029] The Trichoderma harzianum in the embodiments of the present application is Trichoderma harzianum Rifai ACCC30371 strain. All reagents used are commercially available.

[0030] Example 1

[0031] Preparation of the solid microbial inoculant, comprising the following steps:

[0032] (1) Preparation of spore solution:

[0033] The Trichoderma harzianum strain is transferred to PDA medium with an inoculation loop, and is cultured in a mold incubator at 28-32°C for 5 days. Then, the Trichoderma harzianum strain is transferred to sterilized PDB medium with an inoculation loop, and is cultured in a shaking incubator at 28-32°C and 150-200 r / min for 2-3 days to prepare Trichoderma harzianum spore solution. The spore solution is diluted to a concentration of 1×10 5 individuals·mL -1 .

[0034] The PDA culture solution has the following formula: 1L of boiled potato, 20g of glucose, 3g of KH2PO4, 1.5g of MgSO4·7H2O, 8mg of vitamin B1, and 20.0g of agar. After the pH is adjusted to 6.0±0.2, the medium is sterilized at 121°C for 15 minutes. The boiled potato solution is prepared by weighing 200g of peeled potato pieces, boiling in boiling water for 30 minutes, and collecting the filtrate to a volume of 1L.

[0035] The PDB culture medium has the following formula: 1L of boiled potato, 20g of glucose, 3g of KH2PO4, 1.5g of MgSO4·7H2O, and 8mg of vitamin B1. After the pH is adjusted to 6.0±0.2, the medium is sterilized at 121°C for 15 minutes.

[0036] (2) Solid fermentation

[0037] 30g of corn powder and 90g of bran powder are weighed, 55ml of water is added, 2% urea, 1.5% magnesium sulfate, and 0.05% potassium dihydrogen phosphate are added, and the mixture is sterilized in a 250ml flask at 121°C for 30 minutes. After cooling, 1.5ml of Trichoderma harzianum spore solution is inoculated, and the mixture is cultured at 28°C for 7 days. After air-drying at 40°C, Trichoderma harzianum solid fermentation product is obtained. The viable bacterial count in the obtained solid fermentation product is 200 million / g.

[0038] Example 2

[0039] Preparation of the composite microbial inoculant, comprising the following steps:

[0040] (1) Preparation of biological stimulant:

[0041] Kelp polysaccharide, amino acid, potassium fulvate, magnesium sulfate, potassium sulfate, EDTA iron sodium are weighed and mixed according to the mass ratio of 16:16:3:4:4:0.1 to prepare.

[0042] (2) Preparation of the compound microbial agent:

[0043] The biological stimulant and the solid microbial agent are respectively put into a pulverizer for pulverization, and the pulverized raw materials are sieved through a 20-30 mesh sieve;

[0044] After sieving, the biological stimulant and the solid microbial agent are weighed according to the mass ratio of 40:60, and then put into a rotating mixing stirrer for full mixing, the rotating speed of the stirrer is 100 revolutions per minute, the temperature is set to 30°C, the mixing time is 2-3 hours, so that the bacterial content reaches 100 million per gram;

[0045] The solid mixture is further treated by stirring and granulation to obtain solid particles with a particle size of 3 mm;

[0046] The solid particles are dried and dehydrated to a water content of 20%, sieved, and packaged to obtain the compound microbial agent.

[0047] Example 3

[0048] The compound microbial agent prepared in Example 2 is applied to Paspalum notatum, including the following steps:

[0049] After 1.5 g of the compound microbial agent is uniformly mixed with Paspalum notatum seeds, it is sown in a pot with a bottom diameter of 12 cm, a height of 14 cm, an upper opening diameter of 15.5 cm, and a tray at the bottom, the sowing depth is 2 mm, and the soil is covered and watered after sowing, the aboveground part and rhizosphere soil are harvested after 2 months of cultivation as the test sample, and three parallel groups are set.

[0050] Example 4

[0051] The compound microbial agent prepared in Example 2 is applied to Sudan grass, including the following steps:

[0052] After 1.5 g of the compound microbial agent is uniformly mixed with Sudan grass seeds, it is sown in a pot with a bottom diameter of 12 cm, a height of 14 cm, an upper opening diameter of 15.5 cm, and a tray at the bottom, the sowing depth is 2 mm, and the soil is covered and watered after sowing, the aboveground part and rhizosphere soil are harvested after 2 months of cultivation as the test sample, and three parallel groups are set.

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 3 is that the compound microbial agent is replaced by silicon dioxide powder.

[0055] 1.5 g of the silica powder was mixed with the sudan grass seeds and sowed in a pot with a bottom diameter of 12 cm, a height of 14 cm, an upper opening diameter of 15.5 cm, and a tray at the bottom. The sowing depth was 2 mm, and the soil was covered and watered after sowing. After 2 months of cultivation, the aboveground parts were harvested as the test sample. Three parallel groups were set up.

[0056] Comparative Example 2

[0057] The difference between this comparative example and Example 4 is that the composite microbial agent is replaced by silica powder.

[0058] 1.5 g of the silica powder was mixed with the sudan grass seeds and sowed in a pot with a bottom diameter of 12 cm, a height of 14 cm, an upper opening diameter of 15.5 cm, and a tray at the bottom. The sowing depth was 2 mm, and the soil was covered and watered after sowing. After 2 months of cultivation, the aboveground parts were harvested as the test sample. Three parallel groups were set up.

[0059] Example 5

[0060] The plant height of the test samples obtained in Example 3, Example 4, Comparative Example 1, and Comparative Example 2 was measured with a vernier caliper.

[0061] The fresh weight of the plants was accurately weighed with an analytical balance, and then the plants were placed in an envelope and put into an oven for fixation. The oven was set at 80°C and the plants were baked for 12 hours. After cooling, the dry weight of the plants was accurately weighed with an analytical balance.

[0062] The total phosphorus in the leaves was determined by the vanadium-molybdenum yellow colorimetric method (722 type visible spectrophotometer).

[0063] The chlorophyll was extracted with acetone and determined by spectrophotometry (TU-1900 ultraviolet visible spectrophotometer). The results are shown in Table 1.

[0064] Table 1 Effect of composite microbial agent on plant yield

[0065]

[0066] As shown in Table 1, the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus content and chlorophyll of the Paspalum notatum inoculated with the complex microbial agent are respectively increased by 16%, 43.03%, 44.07%, 116.77%, 71.19% and 47.84% compared with the control without the complex microbial agent, the above-ground parameters of the plant inoculated with the complex microbial agent are greatly improved compared with the control without the complex microbial agent, and there is a significant difference between the groups (P<0.05); the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus content and chlorophyll of the Sorghum sudanense inoculated with the complex microbial agent are respectively increased by 15%, 77.41%, 149.20%, 119.26%, 94.16% and 56.16% compared with the control without the complex microbial agent, the above-ground parameters of the plant inoculated with the complex microbial agent are greatly improved compared with the control without the complex microbial agent, and there is a significant difference between the groups (P<0.05), which proves that the complex microbial agent has a good growth promoting effect.

[0067] The total organic carbon (SOC) is determined according to the method NY / T1121.6-2006 Soil Organic Matter Determination; the available phosphorus (aP) and water-soluble phosphorus (H2O-P) are determined by the molybdenum-antimony anti-colorimetric method (722 type visible spectrophotometer); and the total nitrogen is determined according to the method HJ717-2014 Determination of Total Nitrogen by Kjeldahl Method. The measured results are shown in Table 2.

[0068] Table 2 Effect of the complex microbial agent on soil nutrients

[0069]

[0070] As shown in Table 2, the contents of soil organic carbon, available phosphorus, water-soluble phosphorus and total nitrogen are all increased in the treatment group with the complex microbial agent compared with the control group, which indicates that the complex microbial agent has not only an obvious growth promoting effect on plants and improves crop yield, but also can effectively improve the physical and chemical properties of soil, increase the fertility of soil, reduce the use amount of chemical fertilizer and save cost.

[0071] Example 6

[0072] This example is the same as Example 2, except that the biological stimulant and the microbial agent in the complex microbial agent are prepared in a mass ratio of 35:65, and the effective bacteria quantity of the complex microbial agent is not less than 100 million / g.

[0073] Example 7

[0074] This example is the same as Example 3, except that the complex microbial agent prepared in Example 6 is applied to Paspalum notatum, and the rest is the same.

[0075] Example 8

[0076] The embodiment is the same with embodiment 2, except that the biological stimulant and the microbial agent in the compound microbial agent are prepared in a mass ratio of 45:55, and the effective bacteria number of the compound microbial agent is not less than 100 million / g.

[0077] Example 9

[0078] The embodiment is the same with embodiment 3, except that the compound microbial agent prepared in embodiment 8 is applied to bahia grass, and the rest is the same.

[0079] The aboveground parts of the test samples obtained in embodiment 7 and embodiment 9 are taken as test samples, and the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus content and chlorophyll content of the samples are detected, and the detection method is the same as that in embodiment 5, and the detection results are shown in table 3; the soil nutrient parameters after 2 months of culture are detected, and the detection method is the same as that in embodiment 5, and the detection results are shown in table 4.

[0080] Table 3

[0081]

[0082] As can be seen from table 3, compared with comparative example 1, the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus and chlorophyll of bahia grass are all improved by 10%, 40.36%, 35.26%, 111.98%, 75.42% and 47.84% respectively by using the compound microbial agent in embodiment 7; the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus and chlorophyll of bahia grass are all improved by 10%, 45.75%, 32.67%, 109.28%, 67.80% and 42.67% respectively by using the compound microbial agent in embodiment 9. The compound microbial agents used in embodiment 7 and embodiment 9 have a growth promoting effect on plants.

[0083] Table 4

[0084]

[0085] As can be seen from table 4, compared with comparative example 1, the soil organic carbon, available phosphorus, water-soluble phosphorus and total nitrogen contents are increased in the treatment groups of the compound microbial agent in embodiment 7 and embodiment 9, which can effectively improve the physical and chemical properties of the soil, increase the fertility of the soil, reduce the use amount of chemical fertilizers and save costs.

[0086] Comparative example 3

[0087] The difference between the present comparative example and embodiment 2 is that the components of the biological stimulant are: not including potassium sulfate, magnesium sulfate EDTA iron sodium, and instead of silicon dioxide powder, and the rest of the steps are the same as embodiment 2, to prepare the compound microbial agent and apply it to sudan grass, the steps are the same as embodiment 4.

[0088] Comparative example 4

[0089] The difference between the present comparative example and Example 2 is that kelp polysaccharide, amino acid, potassium fulvic acid are mixed in a mass ratio of 22:18:3 to prepare the biological stimulant, and the remaining steps are the same as those of Example 2. The compound microbial agent is prepared and applied to sudan grass, and the steps are the same as those of Example 4.

[0090] Comparative Example 5

[0091] The difference between the present comparative example and Example 2 is that kelp polysaccharide, amino acid, potassium fulvic acid are mixed in a mass ratio of 22:18:3 to prepare the biological stimulant, and the remaining steps are the same as those of Example 2. The compound microbial agent is prepared and applied to sudan grass, and the steps are the same as those of Example 4.

[0092] Comparative Example 6

[0093] The difference between the present comparative example and Example 2 is that kelp polysaccharide, amino acid, potassium fulvic acid, potassium sulfate, magnesium sulfate, and EDTA iron sodium are mixed in a mass ratio of 16:16:3:10:10:0.25 to prepare the biological stimulant, and the remaining steps are the same as those of Example 2. The compound microbial agent is prepared and applied to sudan grass, and the steps are the same as those of Example 4.

[0094] The above-ground parts of the samples obtained in Comparative Examples 3-6 are used as test samples, and the germination rate, plant height, fresh weight, dry weight, leaf total phosphorus content, and chlorophyll content of the samples are detected, and the detection methods are the same as those of Example 5. The detection results are shown in Table 5. The soil nutrient parameters after 2 months of culture are detected, and the detection methods are the same as those of Example 5. The detection results are shown in Table 6.

[0095] Table 5

[0096]

[0097] As can be seen from Table 5, compared with Comparative Examples 2-6, the composite microbial agent provided by the application can improve the germination rate, plant height, fresh weight, dry weight, total phosphorus in leaves and chlorophyll of sudan grass, the germination rate is increased by 16%, 10%, 10%, 14% and 8% respectively, the plant height is increased by 77.41%, 23.33%, 32.70%, 32.25% and 20.40% respectively, the fresh weight is increased by 149.20%, 27.03%, 24.42%, 19.89% and 12.76% respectively, the dry weight is increased by 119.26%, 27.41%, 28.36%, 23.64% and 13.24% respectively, the total phosphorus in leaves is increased by 94.16%, 27.88%, 43.01%, 17.70% and 18.75% respectively, and the chlorophyll is increased by 56.16%, 20.39%, 26.39%, 29.43% and 14.02% respectively, the effect of the composite microbial agent used in Example 4 is better, the promotion of the germination rate, plant height, fresh weight, dry weight, total phosphorus in leaves and chlorophyll is most obvious, which indicates that the composite microbial agent has better effect on plant growth promotion.

[0098] Table 6

[0099]

[0100] As can be seen from Table 6, the composite microbial agent provided by the application can also increase the content of soil organic carbon, total nitrogen, water-soluble phosphorus and available phosphorus, can significantly improve the nutrient components in the soil, and promote plant growth.

[0101] The composite microbial agent prepared by combining various biological stimulants and trichoderma harzianum agent can simultaneously play the effects of soil improvement, auxiliary nutrient absorption and crop yield improvement, can reduce the use amount of chemical fertilizer in agricultural production, save cost, is convenient to prepare, simple to use, and has the advantages of safety, high efficiency and environmental protection.

[0102] It should be noted that the above examples are only used to illustrate the technical solutions of the application and are not limiting, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the application, which should be covered in the scope of the application.

Claims

1. A complex microbial inoculant for promoting plant growth, characterized in that: It comprises the following components: biological stimulant, solid microbial inoculant; the weight ratio of biological stimulant to solid microbial inoculant is 35-45:55-65; The biological stimulant is composed of kelp extract, amino acid, humic acid, magnesium sulfate, potassium sulfate, and sodium iron EDTA; The solid microbial inoculant is prepared from Trichoderma harzianum, and the preparation method is as follows: spore liquid is prepared from Trichoderma harzianum strain, and the spore liquid is added into solid fermentation medium to prepare solid Trichoderma harzianum inoculant; The mass ratio of the kelp extract, amino acid, humic acid, magnesium sulfate, potassium sulfate, and sodium iron EDTA is 16:16:3:4:4:0.

1.

2. The complex microbial agent according to claim 1, characterized by: The raw material of the kelp extract is 50% kelp polysaccharide concentrated powder; the humic acid is one or more of mineral yellow humic acid, biochemical yellow humic acid, and double-source yellow humic acid; and the amino acid is amino acid raw powder.

3. The complex microbial agent according to claim 1, characterized in that: The effective bacteria number in the Trichoderma harzianum solid fermentation product is 200 million / g.

4. A method for preparing a compound microbial agent for promoting plant growth as described in any one of claims 1 to 3, characterized in that: It comprises the following steps: The biological stimulant and the solid microbial inoculant are respectively crushed and sieved; The sieved biological stimulant and the sieved solid microbial inoculant are fully mixed to obtain a solid mixture; The solid mixture is granulated, dried, sieved, and packaged to obtain the compound inoculant.

5. The production method according to claim 4, characterized by: The sieving mesh size is 20-30 mesh.

6. The use of the compound microbial agent for promoting plant growth according to any one of claims 1-3, wherein the compound microbial agent is applied to the plant or the soil surrounding the plant. The compound inoculant is used in the ways of seed dressing, root dipping, mixed seeding, and mixed application at sowing; and the compound inoculant is used in the way of broadcasting at crop transplanting.

7. The application of the compound microbial agent for promoting plant growth as described in claim 6, characterized in that: The application amount of the compound inoculant is 1-3 kg per mu of field for high-fertility soil and 4-6 kg per mu of field for low-fertility soil.

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