Method for preparing microbial fertilizer from earthworm raw material and application of microbial fertilizer in soil improvement

Abstract

The invention discloses a method for preparing a microbial fertilizer from earthworm raw materials and application of the microbial fertilizer in soil improvement, and belongs to the field of microbial fertilizers. The microbial fertilizer is a solid culture obtained by adding 1%-4% of earthworm powder into a solid culture medium for fermenting bacillus subtilis and aspergillus oryzae and fermenting. The preservation number of the aspergillus oryzae is CICC 2400. The optimal method for preparing the microbial fertilizer is obtained by optimizing the preparation method of the microbial fertilizer, the addition amount of the earthworm powder, the strain variety and the like. Finally, by adding the earthworm powder into a solid culture medium of fermented bacillus subtilis and aspergillus oryzae, the microbial fertilizer prepared by combined use of the earthworm powder and the two strains of bacteria can significantly improve the structure, nutrition and the like of continuous cropping soybean planting soil, and also can improve the yield of soybeans and improve the quality of the soybeans.

Description

Technical Field

[0001] The invention relates to the field of microbial fertilizers, and in particular to a method for preparing microbial fertilizers using earthworm raw materials and an application of the method in improving soil. Background Art

[0002] Soybean is one of the important food crops in my country. It is rich in nutrients and is a source of high-quality plant protein. Heilongjiang is the main province for soybean cultivation, but soybean is one of the main crops with low yields in Heilongjiang Province. Low soybean yields are not only affected by natural disasters such as low rainfall and low temperature, but also by repeated cropping. The result of repeated cropping is not only low soybean yields, but also poor quality and serious diseases and insect pests. Related studies have found that the main reasons for the reduction in soybean yields in continuous cropping include: (1) changes in soil nutrients: the content of hydrolyzed nitrogen and available potassium in the soil decreases, and the content of zinc and boron decreases exponentially; (2) changes in soil biological activity: various enzymes in the soil, such as proteases, phosphatases, and invertases, are significantly related to soil fertility, and the activities of various enzymes decrease with the increase in the number of continuous cropping years; (3) changes in soil pH: continuous cropping will lead to deterioration of soil physical properties, increased bulk density, increased macropores, compacted soil, poor light transmittance, and imbalance of the three phases, which is not conducive to root penetration and causes changes in soil pH. The soybean roots secrete acidic substances into the tillage layer every year, resulting in the accumulation of acidic substances in the tillage layer and a decrease in pH. It can be seen that continuous cropping is mainly due to the direct impact on soil structure, nutrients and biological activity, which in turn causes changes in soil structure, a decrease in soil nutrients and active substances, and an imbalance in the soil environment.

[0003] At present, the reduction in soybean production caused by continuous cropping is mainly improved through chemical agents, fertilizer retainers, and the use of resistant varieties. However, these methods have not fundamentally changed the problem of soybean production reduction. Long-term use of chemical agents may also cause drug residues; fertilizer retainers can only be adjusted for specific influencing elements; although replacing resistant varieties is simple, there is a problem of increasing input costs every year. In addition, resistant varieties will also reappear the problem of reduced production as they age. This method requires continuous improvement and supply of resistant varieties, and the input cost will be higher. Microbial fertilizers are products that use the life activities of microorganisms to cause crops to obtain specific fertilizer effects. They contain a large number of beneficial microorganisms, which can improve crop nutritional conditions, fix nitrogen, and activate some ineffective nutrients in the soil, creating a good soil microecological environment to promote crop growth, and are used in crop planting. There have been reports on microbial fertilizers for reducing crop yields or improving soil structure, but the effects of various microbial fertilizers on the market vary. There are currently few reports on special microbial fertilizers for the problem of soybean production reduction in Heilongjiang. Therefore, the development of a new type of microbial fertilizer is particularly important to solve the problem of soybean production reduction in Heilongjiang. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing microbial fertilizer using earthworm raw materials and its application in improving soil, so as to solve the problems existing in the above-mentioned prior art. By adding earthworm powder to the solid culture medium for fermenting Bacillus subtilis and Aspergillus oryzae, the microbial fertilizer prepared by combined use can significantly improve the soil structure and nutrition of continuous soybean planting, and can also increase the yield of soybeans and improve the quality of soybeans.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The invention provides a microbial fertilizer. The microbial fertilizer is obtained by adding 1%-4% earthworm powder to a solid culture medium for fermenting bacillus subtilis and aspergillus oryzae to obtain a solid culture.

[0007] Preferably, the Aspergillus oryzae has a deposit number of CICC 2400.

[0008] Optionally, the solid culture medium comprises the following components in parts by weight: 80-100 parts of bran powder, 10-15 parts of cottonseed cake powder and 20-25 parts of water.

[0009] Optionally, the powders of the Bacillus subtilis and the Aspergillus oryzae are mixed in a mass ratio of (2-5):1, and then inoculated into the solid culture medium in an inoculation amount of 3%-7%.

[0010] Preferably, the weight ratio of the powder of Bacillus subtilis to that of Aspergillus oryzae is 3.5:1.

[0011] The invention also provides a method for preparing the microbial fertilizer, comprising the steps of adding 1%-4% earthworm powder to a solid culture medium for fermenting Bacillus subtilis and Aspergillus oryzae, and obtaining a solid culture through solid fermentation and culture.

[0012] The present invention also provides an application of the microbial fertilizer in increasing soybean yield and / or improving soybean quality.

[0013] Preferably, improving soybean quality comprises reducing fatty acid content.

[0014] The invention also provides application of the microbial fertilizer in improving soil.

[0015] The present invention also provides a method for improving soil, comprising the step of applying the microbial fertilizer to the soil, wherein 4-6 kg of the microbial fertilizer is applied to each mu of soil.

[0016] The present invention discloses the following technical effects:

[0017] The present invention obtains a solid culture by adding earthworm powder to a solid culture medium for culturing Bacillus subtilis and Aspergillus oryzae for solid fermentation, which can be applied to soybean planting as a microbial fertilizer, especially in continuous soybean planting. It is found through experiments that the use of the microbial fertilizer can significantly improve the enzyme activity of multiple enzymes in the soil, promote the improvement of soil structure, microorganisms and nutrition, provide better environmental conditions and nutritional conditions for plants to absorb nutrients in the soil, significantly increase soybean yield, and improve the quality of soybeans, provide better quality soybean planting resources and materials, and lay a theoretical foundation for solving the problem of reduced yield of continuous soybean planting in Heilongjiang Province. The present invention realizes the improvement of soil structure and nutrition of continuous soybean planting under specific conditions through the synergistic effect of strains and earthworm powder, provides a new biological fertilizer for increasing the yield of continuous soybeans and improving the quality, and has the value of wide promotion and application. DETAILED DESCRIPTION

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0019] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0020] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0021] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0022] The words “include,” “including,” “have,” “contain,” etc. used in this article are open-ended terms, meaning including but not limited to.

[0023] The microbial fertilizers involved in the present invention, also known as biological fertilizers, inoculants or bacterial manures, refer to a type of fertilizer products that use the life activities of microorganisms as the core to enable crops to obtain specific fertilizer effects. There are many types of microbial fertilizers, which are generally divided into two categories: one is a narrow sense of microbial fertilizers, which increase the supply of plant nutrients (including the supply of plant nutrients in the soil and production environment) through the life activities of microorganisms, resulting in the improvement of plant nutritional status and thus the increase in yield. The representative variety of this type of microbial fertilizer is rhizobium fertilizer; the other is a broad sense of microbial fertilizers, which refers to the life activities of microorganisms therein, which can not only increase the supply of plant nutrients, but also produce plant growth hormones, promote the absorption and utilization of nutrients by plants, or have antagonistic effects on the pathogenicity of certain pathogenic microorganisms, reduce crop diseases and insect pests and promote the increase in crop yields. The microbial fertilizers prepared by the present invention refer to broad sense of microbial fertilizers.

[0024] The microbial fertilizers involved in the present invention can be divided into five categories according to the types of microorganisms: ① bacterial fertilizers (such as rhizobium fertilizers, nitrogen-fixing fertilizers, phosphate-dissolving fertilizers, potassium-dissolving fertilizers, and photosynthetic fertilizers); ② actinomycete fertilizers (such as antibiotic fertilizers); ③ fungal fertilizers (mycorrhizal fungal fertilizers: including ectomycorrhizal agents and endomycorrhizal agents); ④ algae fertilizers (such as nitrogen-fixing cyanobacteria fertilizers); ⑤ composite microbial fertilizers, that is, fertilizers formed by combining two or more microorganisms in a certain proportion. The microbial fertilizer prepared by the present invention refers to composite microbial fertilizers. Composite microbial fertilizers belong to compound fertilizers, and their compound contents and forms are relatively diverse, including combinations of multiple microorganisms, combinations of beneficial microorganisms and different additives, etc., wherein the additives include composite products of multiple additives such as organic matter (livestock and poultry manure, leather charcoal, lignite, etc.), inorganic matter (fertilizers, trace elements), etc.

[0025] The earthworm powder involved in the present invention is obtained by grinding earthworms into powder as raw materials. Among them, earthworms are invertebrates of the genus Lumbricidae of the class Oligochaeta. In traditional Chinese medicine, they are also called earthworms. They are one of the traditional Chinese medicinal materials. Medical works such as "Qianjin Fang" and "Compendium of Materia Medica" describe the use of earthworms as medicine and medicinal purposes. Earthworms are salty in taste and cold in nature. They can regulate the two pathways and have the effects of clearing heat, calming the liver, and relieving asthma. They are used to treat convulsions, red eyes, stroke and other symptoms. Earthworms are rich in protein and various amino acids. They are good protein feeds. Feeding livestock and poultry can promote growth, fattening, and increase egg production. Earthworms can loosen the soil, improve the pellet structure, improve the soil acidity and alkalinity and increase fertility, promote the activity of nitrifying bacteria in the soil, keep the soil moist, and increase crop yields.

[0026] Fertilizers containing earthworm powder are already available in the prior art. A more specific implementation method is as follows: a new type of organic fertilizer, comprising the following raw materials in parts by weight: 104-156 parts of sheep manure, 93-136 parts of pig manure, 84-115 parts of dog manure, 15-20 parts of tofu dregs, 7-14 parts of sugar residues, 8-12 parts of edible fungus residues, 18-32 parts of earthworm powder, 10-16 parts of composite bacteria, 2-3 parts of trace elements, 2-4 parts of organic water-retaining agent, 1-2.5 parts of dispersant, 0.8-2 parts of organic conditioner, 0.6-1.6 parts of penetrant, 0.4-0.8 parts of regulator, 0.9-1.7 parts of viscosity enhancer, and 0.3-0.6 parts of synergist. Another example: organic fertilizer includes the following materials in parts by weight: 50 parts of human and animal feces, 10 parts of earthworm powder, 5 parts of feather powder, 30 parts of rice husk, 15 parts of frozen green extract, 20 parts of pokeweed extract, 20 parts of seaweed, 100 parts of red date residue, 10 parts of lemongrass, and 20 parts of locust bark. Another example: a saline-alkali land soil conditioner, the saline-alkali land soil conditioner is made of the following materials in parts by weight: 100-200 parts of humic acid, 50-100 parts of seaweed mud, 50-100 parts of biochar, 1-5 parts of biological bacteria agent, 1-5 parts of biological enzyme agent, 50-100 parts of pine needle powder, 50-100 parts of beer lees, 20-50 parts of sulfur slag, 20-50 parts of bentonite, 100-2 00 parts, 30-50 parts of rice straw, 20-30 parts of feather powder, 20-30 parts of earthworm powder, 15-35 parts of amino acid chelate liquid, 10-20 parts of chitosan, 20-30 parts of corn starch, 20-50 parts of coconut bran, 20-50 parts of rice bran, and 50-100 parts of bamboo vinegar; the biological bacterial agent includes yeast, actinomycetes, bacillus, and nitrogen-fixing bacteria; and the biological enzyme agent includes papain and keratinase. The above-mentioned prior art solutions all involve earthworm powder, but it can also be seen that earthworm powder is only one of the raw materials and needs to be combined with a variety of organic and / or inorganic substances and / or Chinese medicinal materials and / or a variety of bacteria and / or biological enzymes. That is to say, the fertilizers containing earthworm powder prepared in the prior art are all obtained by exogenously inputting the above-mentioned multiple nutrients or enzymes into the soil to change the structure or nutrients of the soil and regulate the ecological environment. There are few prior art solutions that only rely on the effects of earthworm powder and composite bacteria to regulate the soil ecological environment, and there is no disclosure of a solution to regulate the soil ecological environment by adding 1%-4% earthworm powder to the solid culture medium of the bacterial strain, and the better solution is to add 3.3% earthworm powder.

[0027] The soybeans involved in the present invention are Heilongjiang soybeans, which are important food crops in Heilongjiang Province. They have round and full grains, thin yellow skin, and contain nutrients such as oil, protein, and amino acids. The growth period of soybeans is usually 100-150 days, and the growth cycle includes stages such as seed germination, emergence, growth, flowering, pod formation, and grain filling.

[0028] The soybean fatty acid involved in the present invention mainly includes oleic acid, linoleic acid, linolenic acid, palmitic acid and stearic acid, wherein oleic acid and linoleic acid are unsaturated fatty acids, which have an important influence on the quality of soybean oil. The higher the unsaturated fatty acid content, the better the quality of soybean oil. In the embodiment of the present invention, it is mainly the total amount of oleic acid and linoleic acid.

[0029] The soy protein involved in the present invention, whose full name is soy protein, refers to the protein contained in soy products, with a content of more than 38%, which is 4 to 5 times that of cereal foods. Soy protein is a plant protein and is one of the important indicators for evaluating the quality of soybeans.

[0030] The earthworm powder and Bacillus subtilis used in the following examples of the present invention are all purchased through conventional commercial channels. The earthworm powder used in the present invention is purchased from Bozhou Wufang Jiuru Pharmaceutical Co., Ltd., and the Bacillus subtilis powder is purchased from Baoding Wobang Organic Fertilizer Production Co., Ltd. Aspergillus oryzae (CICC 2400) is purchased from the China Industrial Microbiological Culture Collection Management Center. The public can purchase earthworm powder and Bacillus subtilis from the above channels or other commercial sources, and obtain Aspergillus oryzae from the above collection center.

[0031] After Aspergillus oryzae is activated, it is inoculated into malt juice liquid medium, and cultured under shaking conditions of 32° C. and 220 rpm for 4 days, and the fermentation liquid is collected and freeze-dried to obtain Aspergillus oryzae powder for later use.

[0032] Prepare a solid culture medium (add 15g agar to the above-mentioned Aspergillus oryzae wort liquid culture medium and sterilize it). Inoculate Aspergillus oryzae into the solid fermentation medium, culture it at 32°C for 3 days, remove Aspergillus oryzae on the solid culture medium aseptically, and then inoculate Bacillus subtilis and culture it for 48h; while inoculating Bacillus subtilis, inoculate Bacillus subtilis in equal amounts into the solid culture medium and culture it for 48h. The results show that Bacillus subtilis grows well in both culture media, indicating that there is no antagonism between the two bacteria and they can coexist in the same culture environment.

[0033] Example 1 Compounding Bacillus subtilis and Aspergillus oryzae

[0034] Bacillus subtilis powder and Aspergillus oryzae powder were compounded according to the components shown in Table 1, and the number of viable bacteria was determined by plate colony counting method (culture conditions: 32° C. for 3 days).

[0035] Table 1 Proportion of bacterial strains

[0036]

[0037] It can be seen from Table 1 above that when Bacillus subtilis and Aspergillus oryzae were compounded at a mass ratio of 3.5:1, the number of viable bacteria was the largest, so this ratio was used in subsequent experiments.

[0038] Embodiment 2 A kind of microbial fertilizer

[0039] The preparation method comprises the following steps:

[0040] (1) Grind the earthworms into powder and pass it through a 100-mesh sieve to obtain earthworm powder.

[0041] (2) adding 1% earthworm powder to a solid fermentation medium, mixing uniformly, and then inoculating composite bacterial powder (Bacillus subtilis powder and Aspergillus oryzae powder are uniformly mixed according to a mass ratio of 3.5:1), the inoculation amount is 6%, the fermentation condition is 32° C. and fermentation is performed for 4 days, the solid culture is collected, dried, and crushed into powder to obtain a microbial fertilizer. The solid culture medium comprises the following components in parts by weight: 100 parts of bran powder, 10 parts of cottonseed cake powder, and 25 parts of water.

[0042] Embodiment 3 A kind of microbial fertilizer

[0043] The preparation method comprises the following steps:

[0044] (1) Grind the earthworms into powder and pass it through a 100-mesh sieve to obtain earthworm powder.

[0045] (2) Add 2% earthworm powder to the solid fermentation medium, mix well, then inoculate composite bacterial powder (Bacillus subtilis powder and Aspergillus oryzae powder are mixed well according to a mass ratio of 3.5:1), the inoculation amount is 3%, the fermentation condition is 32° C. and fermentation is for 4 days, the solid culture is collected, dried, and crushed into powder to obtain a microbial fertilizer. The solid culture medium comprises the following components in parts by weight: 80 parts of bran powder, 12 parts of cottonseed cake powder, and 20 parts of water.

[0046] Embodiment 4 A kind of microbial fertilizer

[0047] The preparation method comprises the following steps:

[0048] (1) Grind the earthworms into powder and pass it through a 100-mesh sieve to obtain earthworm powder.

[0049] (2) adding 4% earthworm powder to a solid fermentation medium, mixing uniformly, and then inoculating composite bacterial powder (Bacillus subtilis powder and Aspergillus oryzae powder are uniformly mixed according to a mass ratio of 3.5:1), the inoculation amount is 7%, the fermentation condition is 32° C. and fermentation is performed for 4 days, the solid culture is collected, dried, and crushed into powder to obtain a microbial fertilizer. The solid culture medium comprises the following components in parts by weight: 90 parts of bran powder, 15 parts of cottonseed cake powder, and 23 parts of water.

[0050] Example 5-Example 8

[0051] Compared with Example 2, only the amount of earthworm powder added is different, as shown in Table 2 below.

[0052] Table 2 Example 5-Example 8 earthworm powder addition amount

[0053] Example Earthworm powder addition amount Example 5 1.5％ Example 6 2.5％ Example 7 3％ Example 8 3.5％

[0054] Comparative Example 1

[0055] The only difference from Example 8 is that earthworm powder, Bacillus subtilis and Aspergillus oryzae powder are not fermented using solid culture medium, that is, earthworm powder, Bacillus subtilis and Aspergillus oryzae powder in equal amounts to those in Example 8 are directly mixed to obtain microbial fertilizer.

[0056] Comparative Example 2

[0057] The only difference from Example 8 is that no earthworm powder is added to the solid culture medium. The other method steps are the same.

[0058] Comparative Example 3

[0059] The only difference from Example 8 is that Bacillus subtilis is not included. The other method steps are the same.

[0060] Comparative Example 4

[0061] The only difference from Example 8 is that Aspergillus oryzae is not included. Other method steps are the same.

[0062] Comparative Example 5

[0063] The only difference from Example 8 is that the amount of earthworm powder added is 5%. The other steps are the same.

[0064] Application Example 1

[0065] The above-mentioned Examples 2-8 and Comparative Examples 1-5 were experimentally potted for verification. On the land where soybeans (Suinong No. 26) were planted for four consecutive years, the soil from the surface to a depth of 30 cm was taken according to the five-point sampling method and mixed evenly, and then the soil was put into the flower pot in equal amounts, and 4 soybean seeds were sown in each pot for potted experiments; when the seedling height grew to 8-10 cm, microbial fertilizer was used for root irrigation treatment, and the treatment method was: 1g of microbial fertilizer was used for each pot, and the root irrigation treatment was performed after diluting it 5 times with water. Grouping is as follows: Examples 2-8 are treated with the microbial fertilizers prepared by corresponding Examples 2-Example 8, numbered S1-S7; Comparative Examples 1-5 are treated with the microbial fertilizers prepared by corresponding Comparative Examples 1-Comparative Examples 5, numbered D1-D5; and the control group is treated with water at the same time. After 30 days of treatment, the enzyme activity (phosphatase, urease, sucrase and protease) in the soil, as well as the soil pH value, were measured. The results are shown in Tables 3-4.

[0066] Phosphatase is an enzyme that catalyzes phosphate transfer reactions and promotes the decomposition and utilization of organic phosphorus. The activity of phosphatase can reflect the supply capacity of organic phosphorus in the soil and the activity of microorganisms, and is one of the important indicators for evaluating soil fertility and ecosystem health. Phosphatase was determined using the disodium phenyl phosphate colorimetric method, and the results are shown in Table 3.

[0067] Urease is an enzyme that can catalyze the decomposition of urea and can reflect the nitrogen supply capacity and microbial activity in the soil. The activity of urease can evaluate the transformation and utilization of nitrogen in the soil, and plays an important role in guiding agricultural production and managing soil quality. Urease was determined by sodium phenol-sodium hypochlorite colorimetry, and the results are shown in Table 3.

[0068] Sucrase is an enzyme that can catalyze the decomposition of sucrose and can reflect the decomposition capacity of carbohydrates in the soil. The activity of sucrase can evaluate the microbial activity and material metabolism in the soil, and plays an important role in understanding the energy flow and material cycle of the soil ecosystem. Sucrase was determined by 3,5-dinitrosalicylic acid colorimetry, and the results are shown in Table 3.

[0069] Proteases are involved in the transformation of amino acids, proteins and other organic compounds containing protein nitrogen in the soil. Their hydrolysis products are one of the nitrogen sources for higher plants. Soil proteases are related to soil organic matter content, nitrogen and other soil properties. Proteases were determined using the copper salt colorimetric method, and the results are shown in Table 3.

[0070] After continuous soybean planting, soil acidity increases, and the activities of urease, phosphatase, and protease also show a decreasing trend with the increase of the number of consecutive cropping years, while sucrase increases. After being treated with the microbial fertilizer prepared by the present invention, the activities of phosphatase, urease, and protease in the soil can be significantly improved, while sucrase has no significant change, indicating that the application of microbial fertilizer has a significant regulatory effect on the change of enzyme activity.

[0071] Enzyme enhancement rate (%) = (enzyme content after microbial fertilizer treatment - enzyme content of soil before initial microbial fertilizer treatment) / enzyme content of soil before initial microbial fertilizer treatment.

[0072] Before transferring into flower pots, the soil collected by the five-point sampling method was mixed evenly, and the contents of phosphatase, urease, sucrase and protease in the soil were measured. See the results of the control group in Table 3.

[0073] Table 3 Determination results of soil enzyme activity

[0074]

[0075] Note: The data in the table are the average values ​​of three replicates.

[0076] As can be seen from the data in the above table, compared with the untreated soil of the control group, after the treatment of the microbial fertilizer of the present invention, the enzyme activities of phosphatase, urease and protease can be significantly improved, especially the S7 group (i.e. embodiment 8) has the most obvious effect. After S1-S7 and D1-D5 treatment, sucrase has no obvious change. The result data can also be seen that the addition of the mixed mode, the kind of bacterial strain, the amount of earthworm powder, etc. for earthworm powder, bacillus subtilis and aspergillus oryzae, can directly affect the enzyme activity in the soil, the inventor analyzes according to many years of practical experience, earthworm powder as a component containing multiple nutrients such as protein, fat, carbohydrate, vitamins and minerals, directly after mixing with two strains, can not be fully utilized by bacterial strain as nutrients, and directly applied to soil after, due to the problems that there is thalline environmental imbalance and nutrient deficiency in the soil itself, so, even if earthworm powder contains multiple nutrients, it can not form a good metabolic chain with thalline or nutritional components in the soil, also causes nutrients can not be absorbed or converted by the soil. And the bacillus subtilis and aspergillus oryzae used by the present invention have no antagonism, can live in the same soil environment, and do not utilize two kinds of bacterial strains to compound and improve multiple enzyme activities in soil, especially change the enzyme activity related report and application in the soybean planting land of many years.But the solid culture after the simple aspergillus oryzae compound earthworm powder fermentation can improve phosphatase, urease and protease enzyme activities in relative contrast, but after aspergillus oryzae and bacillus subtilis and earthworm powder are compounded, the above-mentioned enzyme activities in soil can be significantly improved.Mainly due to the enzyme or active substance produced by bacillus subtilis itself, better environmental conditions and nutrients can be provided for the survival and metabolism of aspergillus oryzae in soil, and the existence of earthworm powder in addition provides a nutritional basis for the initial activity and expansion of two kinds of bacteria as a nutritional basis, after applying to soil, it can make it form a dominant beneficial bacteria colony quickly, for balancing beneficial bacteria and harmful bacteria in soil and laying the foundation.As can be seen, earthworm powder, bacillus subtilis and aspergillus oryzae three are synergistic, which improves the enzyme activity of multiple enzymes in soil. As for the excessive amount of earthworm powder, it not only failed to significantly increase the activity of multiple enzymes in the soil, but on the contrary decreased it compared with the microbial fertilizer prepared in the present application. This may be because the two strains of bacteria have a "saturation point" in the utilization of nutrients. Too much or too little may affect the production of metabolic substances and the rate of reproduction. Therefore, the present invention can achieve the best effect only under the specific conditions and within the specific range provided (such as Examples 2 to 8 of the present invention).

[0077] Table 4 pH value measurement results

[0078] sample pH S1 7.0 S2 7.2 S3 7.0 S4 7.0 S5 7.0 S6 7.1 S7 7.0 D1 5.6 D2 6.0 D3 6.3 D4 5.0 D5 6.1 Control group 5.3

[0079] It can be seen from the data in the above table that the use of the microbial fertilizers prepared in Examples 2 to 8 of the present invention can significantly improve the pH value of the soil, which is between 7.0 and 7.2, belonging to neutral soil. Comparative Examples 1 to 5 can also alleviate the pH value of the soil, but the effect is obviously not as significant as that of Examples 2 to 8, and the situation in which only Bacillus subtilis exists in the strain in Group D4 may produce some acidic substances, which not only does not improve the acidic soil, but also makes the soil acidity lower than the control.

[0080] Combining Table 3 and Table 4, after being treated with the microbial fertilizer of Examples 2-8, the soil became neutral and the total activity of phosphatase was also increased. Therefore, the inventors also measured the content of neutral phosphatase and acid phosphatase and found that the content of neutral phosphatase was significantly higher than that of acid phosphatase, which is consistent with the conclusion that the activities of multiple enzymes in the soil are increased and the pH is adjusted to neutral.

[0081] Application Example 2

[0082] The microbial fertilizer prepared in Example 8 was applied to the field test of soybean planting (Suinong No. 26) in Heilongjiang Province. Six plots of the same size in a village in Qiqihar City, Heilongjiang Province were randomly selected as test fields (all plots where soybeans were planted for four consecutive years), and the same method was used for planting and management. They were randomly divided into two groups: the experimental group: the microbial fertilizer of Example 8 was applied to the roots once when the seedling height was 8-10cm after emergence; the root application was applied again during the flowering and podding period; each time, 5kg of microbial fertilizer was applied to each mu of soil, and the microbial fertilizer was diluted 5 times before root irrigation; the control group: the same amount of water was used for root application at the same time as in the embodiment. After maturity, soybean seeds were harvested, and the soybean seed yield and the fatty acid (oleic acid and linoleic acid) and protein content in the soybean seeds were determined. It was found that compared with the control group, the soybean yield of the experimental group increased by 10.01%; the fatty acid content in the soybean seeds increased by 18.35%, and the protein content increased by 15.21%.

[0083] The above results indicate that the present invention can significantly improve the environmental and nutritional conditions of the soil by applying microbial fertilizers to the soil, thereby increasing the plant's absorption of nutrients in the soil, thereby increasing soybean yield and quality, which provides a new method for solving the problem of soybean production reduction in Heilongjiang Province.

[0084] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A microbial fertilizer, characterized in that: The microbial fertilizer is a solid culture obtained by adding 1%-4% earthworm powder to a solid culture medium for fermenting Bacillus subtilis and Aspergillus oryzae.

2. The microbial fertilizer according to claim 1, characterized in that The deposit number of the Aspergillus oryzae is CICC 2400.

3. The microbial fertilizer according to claim 1, characterized in that The solid culture medium comprises the following components in parts by weight: 80-100 parts of bran powder, 10-15 parts of cottonseed cake powder and 20-25 parts of water.

4. The microbial fertilizer according to claim 1, characterized in that The powders of Bacillus subtilis and Aspergillus oryzae are mixed in a mass ratio of (2-5):1, and then inoculated into the solid culture medium in an inoculation amount of 3%-7%.

5. The microbial fertilizer according to claim 1, characterized in that The weight ratio of the powder of the Bacillus subtilis to that of the Aspergillus oryzae is 3.5:

1.

6. The method for preparing the microbial fertilizer according to any one of claims 1 to 5, characterized in that: The method comprises the steps of adding 1%-4% earthworm powder to a solid culture medium for fermenting bacillus subtilis and aspergillus oryzae, and obtaining a solid culture through solid fermentation culture.

7. Use of the microbial fertilizer according to any one of claims 1 to 5 in increasing soybean yield and / or improving soybean quality.

8. The use according to claim 7, characterized in that The improving soybean quality includes reducing fatty acid content.

9. Use of the microbial fertilizer according to any one of claims 1 to 5 in improving soil.

10. A method for improving soil, characterized in that: The method comprises the step of applying the microbial fertilizer according to any one of claims 1 to 5 to the soil, wherein 4 to 6 kg of the microbial fertilizer is applied to each acre of soil.

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