Preparation process and application of microbial fertilizer

Abstract

The invention discloses a preparation process and application of a microbial fertilizer, and relates to the technical field of microbial fertilizers, and the preparation process comprises the following steps: uniformly mixing cassava residues, mushroom residues and water, and carrying out primary anaerobic fermentation; collecting primary biogas after the primary anaerobic fermentation, separating primary biogas residues, and performing secondary anaerobic fermentation on the primary biogas residues; secondary biogas obtained after secondary anaerobic fermentation is collected, secondary biogas residues are separated out, the secondary biogas residues are subjected to aerobic fermentation, and the microbial fertilizer is obtained after fermentation is finished. The cassava residues and the mushroom residues are subjected to two-time anaerobic fermentation and one-time aerobic fermentation, so that the fermentation of the raw materials is more thorough, the carbon nitrogen ratio in the produced microbial fertilizer is more reasonable, and the effects of safety and no seedling burning can be achieved in the use process.

Description

Technical Field

[0001] This invention relates to the field of microbial fertilizer technology, specifically to a microbial fertilizer preparation process and its application. Background Technology

[0002] Microbial fertilizers, also known as bio-fertilizers, inoculants, or bacterial fertilizers, are a type of fertilizer product that uses the life activities of microorganisms as its core to provide crops with specific fertilization effects. There is a fundamental difference between microbial fertilizers and micronutrient fertilizers: the former are living organisms, while the latter are mineral elements. Microbial resources are abundant, with diverse types and functions, and can be developed into fertilizers with different functions and uses.

[0003] Soil is one of the main natural resources upon which humankind depends for survival and an important component of the human ecological environment. With the increasing pollution from industrial cities and the growing use of chemical fertilizers and pesticides in agricultural production, soil pollution is becoming increasingly serious, especially soil compaction, which severely impacts agricultural development. To address undesirable soil properties and hindering factors, appropriate physical or chemical measures should be taken to improve soil characteristics, increase soil fertility, and boost crop yields. Soil improvement technologies include soil compaction remediation, soil structure improvement, saline-alkali land improvement, acidified soil improvement, soil science work, and soil pollution remediation.

[0004] Most existing fertilizers cause some degree of soil pollution after use, and soil conditioners have poor time-limited improvement effects, requiring repeated improvements to be effective. Therefore, there is an urgent need for a product that can be used as both fertilizer and soil conditioner. Summary of the Invention

[0005] The present invention aims to address the shortcomings of the prior art by providing a preparation process and application of microbial fertilizer, which at least solves some of the technical problems in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A process for preparing a microbial fertilizer includes the following steps: Mix cassava residue, mushroom residue and water evenly and carry out one anaerobic fermentation. The biogas produced after the first anaerobic fermentation is collected and the first biogas residue is separated. The first biogas residue is then subjected to a second anaerobic fermentation. The secondary biogas produced after secondary anaerobic fermentation is collected and the secondary biogas residue is separated. The secondary biogas residue is then subjected to aerobic fermentation, and microbial fertilizer is obtained after the fermentation is completed.

[0007] Furthermore, the cassava residue and mushroom residue undergo anaerobic fermentation followed by crushing and grinding. Optionally, the cassava residue and mushroom residue can be crushed and passed through a 16-20 mesh sieve.

[0008] Furthermore, the mass ratio of the cassava residue to the mushroom residue is (0.8-1.3):(1-2). The moisture content of the cassava residue and mushroom residue is 50-60%.

[0009] Furthermore, the cassava residue, mushroom residue, and water are mixed evenly and placed in a primary anaerobic fermentation tank and sealed. The temperature inside the primary anaerobic fermentation tank is controlled at 20-35℃, and the materials inside the primary anaerobic fermentation tank are continuously stirred for 20-30 days to obtain primary biogas and primary biogas residue liquid.

[0010] Furthermore, the primary anaerobic digester is vacuumed to collect the primary biogas, and then the primary biogas residue is filtered to obtain primary biogas residue and primary wastewater. The primary biogas residue and water are then placed in a secondary anaerobic digester for secondary anaerobic fermentation. The secondary anaerobic digester is sealed, the temperature inside the secondary anaerobic digester is controlled at 20-35℃, and the material inside the secondary anaerobic digester is continuously stirred for 10-20 days to obtain secondary biogas and secondary biogas residue liquid.

[0011] Furthermore, the secondary anaerobic fermenter is vacuumed to collect the secondary biogas, and then the secondary biogas residue is filtered to obtain secondary biogas residue and secondary wastewater. The secondary biogas residue and water are then subjected to aerobic fermentation.

[0012] Furthermore, the aerobic fermentation is carried out using an aeration fermentation method for 40-60 days to obtain microbial fertilizer.

[0013] Furthermore, in the aforementioned anaerobic fermentation, animal manure is added to the raw materials as an inoculum for anaerobic fermentation before fermentation. In the secondary anaerobic fermentation, lactic acid bacteria are added to the mixture of primary biogas residue and water as an inoculum for secondary anaerobic fermentation before fermentation. Bacillus was added as an inoculum in the aerobic fermentation process.

[0014] Furthermore, the application of microbial fertilizers prepared according to the above-mentioned preparation process.

[0015] The beneficial effects of this invention are: This invention involves two anaerobic fermentations and one aerobic fermentation of cassava residue and mushroom residue, resulting in more thorough fermentation of the raw materials. The resulting microbial fertilizer has a more reasonable carbon-nitrogen ratio and can achieve a safe and seedling-free effect during use. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; this repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0018] Cassava residue refers to the waste generated during the processing of cassava, mainly including cassava peel, the fibrous parts of the root and stem, and incompletely utilized cassava particles. The main indicators include crude fiber, crude ash, and moisture.

[0019] Mushroom residue, also known as mushroom compost or mushroom waste, is the remaining substrate after the mushroom (edible fungus) cultivation process. This substrate is usually composed of various organic materials, such as rice straw, sawdust, corn cobs, and cottonseed hulls, which provide essential nutrients for mushroom growth. Although these substrates lose most of their nutritional value after mushroom harvest, they still have high reuse value.

[0020] This invention provides a process for preparing microbial fertilizer, comprising the following steps: Mix cassava residue, mushroom residue and water evenly and carry out one anaerobic fermentation. The biogas produced after the first anaerobic fermentation is collected and the first biogas residue is separated. The first biogas residue is then subjected to a second anaerobic fermentation. The secondary biogas produced after secondary anaerobic fermentation is collected and the secondary biogas residue is separated. The secondary biogas residue is then subjected to aerobic fermentation, and microbial fertilizer is obtained after the fermentation is completed.

[0021] It should be noted that secondary anaerobic fermentation can further degrade organic matter that cannot be completely degraded during the primary anaerobic fermentation, especially recalcitrant substances such as cellulose, hemicellulose, and lignin, thereby increasing the degradation rate of organic matter. Furthermore, secondary anaerobic fermentation can release more fermentable substances, thereby increasing biogas production and improving energy recovery efficiency.

[0022] During the initial fermentation process, certain microbial communities may exhibit dominant growth, leading to system imbalance. Secondary fermentation can rebalance the microbial community, improving the stability and reliability of the fermentation system. The initial fermentation may produce inhibitory substances (such as volatile fatty acids), which may affect subsequent fermentation processes. Secondary fermentation can further degrade these inhibitory substances, reducing negative impacts on the microorganisms.

[0023] Secondary anaerobic fermentation can further increase the biogas content and output during the fermentation process, and further degrade organic matter, making the final biogas residue more stable and mature, and more suitable for use as organic fertilizer. Secondary anaerobic fermentation can effectively reduce the generation of odors and improve the production environment.

[0024] Anaerobic fermentation followed by aerobic fermentation can further decompose the organic acids, alcohols, and small molecule compounds produced during anaerobic fermentation into water and carbon dioxide, thereby completely degrading organic matter and improving the overall degradation efficiency of organic matter. The high temperature generated during aerobic fermentation (usually 55-65℃) can effectively kill pathogens and weed seeds, further improving the safety of the product.

[0025] Combining anaerobic and aerobic fermentation can produce organic fertilizers rich in organic matter, nitrogen, phosphorus, potassium and other nutrients, improving the quality of the fertilizer. The high temperature and microbial activity generated during aerobic fermentation can improve the structure of organic fertilizers, making them looser and beneficial to soil aeration and water retention.

[0026] The microbial community used in this invention is Bacillus subtilis, which gives the microbial fertilizer a strong tolerance to temperature. It can be used in a temperature range of -60 to 60℃ with good results. It can quickly promote the growth of a large number of fine roots and form a protective barrier around the root system to nourish the root system. In addition, the bacterial proteins and biological enzymes produced during the fermentation process can effectively restore the charge balance of the soil and improve the soil.

[0027] In a further embodiment of this example, the cassava residue and mushroom residue are subjected to anaerobic fermentation followed by crushing and grinding. Optionally, the cassava residue and mushroom residue can be crushed and passed through a 16-20 mesh sieve.

[0028] It should be noted that by crushing cassava residue and mushroom residue to the appropriate particle size range, the surface area can be increased, improving the contact efficiency between microorganisms and organic matter, thereby accelerating the fermentation speed. Smaller particle sizes are easier to mix evenly, ensuring consistent fermentation conditions in all parts of the process. However, excessively small particle sizes can lead to overly compacted materials, affecting ventilation and permeability, which may result in uneven anaerobic fermentation. Correspondingly, larger particle sizes can maintain better ventilation and permeability, which is beneficial for aerobic fermentation. However, excessively large particle sizes may lead to uneven mixing, affecting the fermentation effect.

[0029] By selecting cassava residue and mushroom residue sieved through a 16-20 mesh screen, the beneficial effects of the two can be balanced, achieving both uniform mixing and good ventilation and aeration, thus ensuring uniform anaerobic fermentation.

[0030] In a further embodiment of this example, the mass ratio of the cassava residue to the mushroom residue is (0.8-1.3):(1-2). The moisture content of the cassava residue and mushroom residue is 50-60%.

[0031] It should be noted that the mixing ratio of cassava residue and mushroom residue will affect the carbon-nitrogen ratio in the final product, microbial fertilizer. By mixing the cassava residue and mushroom residue evenly according to the above mass ratio, the carbon-nitrogen ratio in the microbial fertilizer product can be made close to the ideal 30:1, which helps to promote the activity of microorganisms and accelerate the composting process.

[0032] When mixing with water, it is necessary to maintain an appropriate moisture level. Ideally, the mixture should be able to form a clump when squeezed in your hand without dripping water. A moisture content within the range described above effectively achieves this. If the mixture is too wet or too dry, it will negatively impact the composting effect.

[0033] In a further embodiment of this example, the cassava residue, mushroom residue, and water are mixed evenly and placed in a primary anaerobic fermentation tank and sealed. The temperature inside the primary anaerobic fermentation tank is controlled at 20-35℃, and the materials inside the primary anaerobic fermentation tank are continuously stirred for 20-30 days to obtain primary biogas and primary biogas residue liquid.

[0034] It should be noted that after the cassava residue, mushroom residue, and water are evenly mixed and placed in the primary anaerobic fermentation tank, the tank should be sealed immediately. This prevents the introduction of new oxygen during the primary anaerobic fermentation process, achieving a better anaerobic fermentation environment. Microbial growth is optimal at a temperature of 20-35℃. Continuous stirring within the primary anaerobic fermentation tank ensures the uniform distribution of gases (such as carbon dioxide and methane) throughout the tank, preventing localized gas accumulation, improving gas utilization, promoting sufficient contact between the substrate and microorganisms, and ensuring that microorganisms can uniformly access nutrients, thereby improving metabolic efficiency. Stirring also prevents the formation and accumulation of scum, reducing the scum layer at the top of the fermentation tank and avoiding interference with gas release and collection. Furthermore, stirring ensures the uniform mixing of various components in the fermentation broth (such as substrate, microorganisms, and metabolites), preventing excessively high or low concentrations in certain areas, ensuring the stability and consistency of the entire fermentation process. Stirring also prevents the accumulation of harmful metabolites (such as ammonia and hydrogen sulfide) in localized areas, reducing their inhibitory effect on microorganisms, maintaining the stability of the fermentation process, and improving fermentation efficiency.

[0035] In a further embodiment of this example, the primary anaerobic digester is vacuumed to collect primary biogas, and then the primary biogas residue is filtered to obtain primary biogas residue and primary wastewater. The primary biogas residue and water are then placed in a secondary anaerobic digester for secondary anaerobic fermentation. The secondary anaerobic digester is sealed, the temperature inside the secondary anaerobic digester is controlled at 20-35℃, and the material inside the secondary anaerobic digester is continuously stirred for 10-20 days to obtain secondary biogas and secondary biogas residue liquid.

[0036] It should be noted that: before removing the primary biogas slurry from the primary anaerobic digester, the primary anaerobic digester should be vacuumed. This can better recover the biogas produced during the primary anaerobic digestion process. Filtering the primary biogas slurry can prevent the large amount of harmful metabolites produced during the primary anaerobic digestion process from inhibiting microorganisms during the secondary anaerobic digestion process, thus maintaining the stability of the secondary fermentation process and improving the fermentation efficiency of the secondary anaerobic digestion.

[0037] Furthermore, the secondary anaerobic fermenter is vacuumed to collect the secondary biogas, and then the secondary biogas residue is filtered to obtain secondary biogas residue and secondary wastewater. The secondary biogas residue and water are then subjected to aerobic fermentation.

[0038] In a further embodiment of this example, the aerobic fermentation is carried out by aeration fermentation for 40-60 days to obtain microbial fertilizer.

[0039] In a further embodiment of this example, animal manure is added to the raw materials as an inoculum for anaerobic fermentation before the first anaerobic fermentation. In the secondary anaerobic fermentation, lactic acid bacteria are added to the mixture of primary biogas residue and water as an inoculum for secondary anaerobic fermentation before fermentation. Bacillus was added as an inoculum in the aerobic fermentation process.

[0040] It should be noted that the inoculum used in the primary anaerobic fermentation process is animal manure, such as cow manure or pig manure. The microbial community in it is highly adaptable and starts up quickly, rapidly establishing a stable anaerobic environment and accelerating the start-up speed of the fermentation system. The lactic acid bacteria used as the inoculum in the secondary anaerobic fermentation process are microorganisms with a higher methanogenic capacity.

[0041] Choosing two different inoculums can introduce a diverse microbial community, enhancing the system's resistance to interference and stability. Microorganisms in different inoculums have different metabolic functions, which can complement each other's deficiencies and improve the stability and tolerance of the entire system. By inoculating in stages, the competition and inhibition caused by introducing a large number of microorganisms at once can be avoided, ensuring that microorganisms at each stage can play their full role.

[0042] Example Cassava residue and mushroom residue were crushed and passed through a 16-20 mesh sieve respectively. Cassava residue and mushroom residue are mixed with water at a mass ratio of (0.8-1.3):(1-2), with a moisture content of 50-60%, until the mixture can be formed into a ball by hand but does not drip water. This mixture, along with animal manure, is placed in a primary anaerobic fermentation tank as inoculum and sealed. The temperature inside the primary anaerobic fermentation tank is controlled at 20-35℃, and the materials inside the tank are continuously stirred for 20-30 days to obtain primary biogas and primary biogas residue liquid. The primary anaerobic fermenter is vacuumed to collect the primary biogas. Then the primary biogas residue is filtered to obtain primary biogas residue and primary wastewater. The primary biogas residue, water and lactic acid bacteria are placed in a secondary anaerobic fermenter for secondary anaerobic fermentation. The secondary anaerobic digester is sealed, the temperature inside the secondary anaerobic digester is controlled at 20-35℃, and the material inside the secondary anaerobic digester is continuously stirred for 10-20 days to obtain secondary biogas and secondary biogas residue liquid. The secondary anaerobic fermenter is vacuumed to collect the secondary biogas. Then, the secondary biogas residue is filtered to obtain secondary biogas residue and secondary wastewater. The secondary biogas residue, water, and Bacillus are fermented by aeration for 40-60 days to obtain microbial fertilizer.

[0043] Comparative Example Microbial fertilizer produced by a company in Xuzhou.

[0044] test The experiment was conducted in an experimental field in Shiji Town, Xinyi City. The experimental field was divided into six experimental areas of the same size, which were marked as experimental areas 1-6. The soil environment in the six experimental areas was basically the same.

[0045] Experimental Group 1: Peach trees were planted in experimental field 1, and 400 kg of the microbial fertilizer in the example was applied per mu. Experimental Group 2: The same peach trees as those in Experimental Group 1 were planted in Experimental Field 2, and 400 kg of the microbial fertilizer from the comparison ratio was applied per mu. Experimental Group 3: Spinach was planted in experimental field 3, and 160 kg of the microbial fertilizer in the fertilization example was applied per mu; Experimental Group 4: The same spinach as in Experimental Group 3 was planted in experimental field 4, and 160 kg of the microbial fertilizer from the comparison ratio was applied per mu. Experimental Group 5: Peanuts were planted in experimental field 5, and 80 kg of the microbial fertilizer in the example was applied per mu; Experimental Group 6: The same peanuts as those in Experimental Group 5 were planted in Experimental Field 6, and 80 kg of the microbial fertilizer from the comparison ratio was applied per mu.

[0046] The field management of experimental groups 1 and 2 was the same, the field management of experimental groups 3 and 4 was the same, and the field management of experimental groups 5 and 6 was the same.

[0047] The root systems of experimental groups 1, 3 and 5 were significantly more vigorous than those of experimental groups 2, 4 and 6, and there was also a significant improvement in yield and product quality.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A process for preparing a microbial fertilizer, characterized in that, Includes the following steps: Mix cassava residue, mushroom residue and water evenly and carry out one anaerobic fermentation. The biogas produced after the first anaerobic fermentation is collected and the first biogas residue is separated. The first biogas residue is then subjected to a second anaerobic fermentation. The secondary biogas produced after secondary anaerobic fermentation is collected and the secondary biogas residue is separated. The secondary biogas residue is then subjected to aerobic fermentation, and microbial fertilizer is obtained after the fermentation is completed.

2. The preparation process of microbial fertilizer according to claim 1, characterized in that, The cassava residue and mushroom residue are subjected to anaerobic fermentation followed by crushing and grinding. Optionally, the cassava residue and mushroom residue can be crushed and passed through a 16-20 mesh sieve.

3. The preparation process of microbial fertilizer according to claim 1, characterized in that, The mass ratio of the cassava residue to the mushroom residue is (0.8-1.3):(1-2). The moisture content of the cassava residue and mushroom residue is 50-60%.

4. The preparation process of microbial fertilizer according to claim 1, characterized in that, After the cassava residue, mushroom residue and water are mixed evenly, they are placed in a primary anaerobic fermentation tank and sealed. The temperature inside the primary anaerobic fermentation tank is controlled at 20-35℃, and the materials inside the primary anaerobic fermentation tank are continuously stirred for 20-30 days to obtain primary biogas and primary biogas residue liquid.

5. The preparation process of microbial fertilizer according to claim 4, characterized in that, The primary anaerobic digester is vacuumed to collect the primary biogas. Then the primary biogas residue is filtered to obtain primary biogas residue and primary wastewater. The primary biogas residue and water are then placed in a secondary anaerobic digester for secondary anaerobic fermentation. The secondary anaerobic digester is sealed, the temperature inside the secondary anaerobic digester is controlled at 20-35℃, and the material inside the secondary anaerobic digester is continuously stirred for 10-20 days to obtain secondary biogas and secondary biogas residue liquid.

6. The preparation process of microbial fertilizer according to claim 5, characterized in that, The secondary anaerobic fermenter is vacuumed to collect the secondary biogas. Then the secondary biogas residue is filtered to obtain secondary biogas residue and secondary wastewater. The secondary biogas residue and water are then subjected to aerobic fermentation.

7. The preparation process of microbial fertilizer according to claim 6, characterized in that, The aerobic fermentation is carried out by aeration fermentation for 40-60 days to obtain microbial fertilizer.

8. The preparation process of microbial fertilizer according to claim 1, characterized in that, In the aforementioned anaerobic fermentation, animal manure was added to the raw materials as an inoculum for anaerobic fermentation before fermentation. In the secondary anaerobic fermentation, lactic acid bacteria are added to the mixture of primary biogas residue and water as an inoculum for secondary anaerobic fermentation before fermentation. Bacillus was added as an inoculum in the aerobic fermentation process.

9. The preparation process of microbial fertilizer according to claim 8, characterized in that, The microbial fertilizer also includes a beneficial complex of bacteria, which includes lactic acid bacteria, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and rooting bacteria.

10. The application of a microbial fertilizer preparation process, characterized in that, Application of microbial fertilizers prepared according to the preparation process described in claims 1-9.