A composite microbial fertilizer and its preparation method and application in enhancing crop stress resistance

Abstract

The invention belongs to the technical field of microbial compound fertilizer, and specifically relates to a compound microbial fertilizer and a preparation method thereof and an application thereof in enhancing crop stress resistance. The invention uses potassium humate, bacterial agent, slow-release silicon and sodium selenite as stress resistance core substances, supplemented with humic acid, a large number of elements and synergist substances, and the substances interact with each other to meet the fertilizer requirement of crops, effectively balance crop nutrition, and improve the stress resistance of crops while improving soil structure, increasing crop yield and improving crop quality.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial compound fertilizers, and in particular relates to a compound microbial fertilizer and a preparation method thereof, and application of the compound microbial fertilizer in enhancing crop stress resistance. Background Art

[0002] Meteorological adverse factors such as drought, low temperature, high temperature, soil salinization, heavy metal pollution, and soil structure degradation have become important limiting factors for current agricultural production. How to more effectively resist the impact of adverse hazards on agricultural production is an important issue facing current agricultural production. Among the many adverse factors, salinization and drought are the most widely distributed adverse factors. Among them, drought is the climate disaster with the greatest impact on agricultural production. For agriculture, when soil salinization occurs, only a small part of the crops can absorb subsequent fertilizers, and most of the fertilizers will be lost with water or fixed by the soil, resulting in reduced production and deterioration of quality. From an ecological perspective, the reduction of the primary productivity of the ecosystem will cause problems such as land desertification and reduction of greenhouse gas fixation. Therefore, drought and salinization have become the main obstacles to the sustainable development of the global and Chinese economy, society, and ecology.

[0003] Drought and salinity have similar impacts on crop production, both of which reduce crop root water absorption, causing crop physiological wilting, leading to crop yield reduction or even failure. Currently, the methods for dealing with drought and salinity hazards mainly include engineering methods, breeding methods, and cultivation methods. Among them, the engineering method mainly uses water conservancy engineering measures to ensure field water supply, and uses engineering measures such as large water pressure alkali to reduce the Na in the soil. + Ions are leached with water, reducing the salt content of the soil; the breeding method is to improve the salt resistance and drought resistance of crops through conventional breeding or transgenic technology; the cultivation method is to improve the soil's water retention capacity and buffering capacity for metal cations through the application of organic fertilizers, mulching and other cultivation methods. Among them, although the engineering method has obvious effects on alleviating salt-alkali stress, the investment cost is high, and it is difficult to implement in areas with scarce water resources and relatively deep groundwater levels (such as the Loess Plateau); while the investment cost of cultivating stress-resistant varieties (such as "sea rice") through breeding methods is low, but the breeding cycle is long. Under the current existing technology, how to establish a method for alleviating crop salt-alkali stress with low investment cost, short cycle and strong usability has become a problem that needs to be solved urgently.

[0004] In production scenarios where it is difficult to solve drought and salinity hazards through engineering measures and new varieties, enhancing the resistance of crops to drought and salinity through fertilization has become an important means of coping with adversity hazards. At present, although researchers have discovered some stress-resistant functional substances, a single substance still cannot effectively improve the stress resistance of crops. Summary of the invention

[0005] The object of the present invention is to provide a composite microbial fertilizer and a preparation method thereof and application in enhancing the stress resistance of crops. The composite microbial fertilizer can effectively enhance the stress resistance of crops and thus achieve the effect of increasing crop yield.

[0006] The invention provides a composite microbial fertilizer, comprising the following raw materials in parts by weight: 150-300 parts of potassium humate, 10-30 parts of potassium fulvic acid, 100-400 parts of macroelements, 10-50 parts of bacterial agents, 150-450 parts of slow-release silicon, 0.02-0.1 parts of sodium selenite, 2-10 parts of synergist and 50-150 parts of binder;

[0007] The bacterial agents include Bacillus albus, arbuscular mycorrhizal fungi and Bacillus subtilis.

[0008] Preferably, the method for preparing the slow-release silicon comprises: mixing silicate with water under stirring until completely dissolved to obtain a 10% dilute silicate solution;

[0009] removing metal cations from the 10% dilute silicate solution to obtain a dilute monosilicic acid solution;

[0010] The dilute monosilicic acid solution is dried to obtain slow-release silicon.

[0011] Preferably, the method for removing metal cations in the 10% dilute silicate solution comprises: passing the 10% dilute silicate solution through a strongly acidic cation exchange resin and maintaining the pH value of the filtrate to be less than 3, to obtain a dilute monosilicic acid solution.

[0012] Preferably, the bacterial agent comprises 5 to 20 parts of Bacillus alexandrus, 3 to 30 parts of arbuscular mycorrhizal fungi and 1 to 5 parts of Bacillus subtilis in parts by weight.

[0013] Preferably, the macro-elements are derived from one or more of urea, ammonium sulfate, potassium dihydrogen phosphate, potassium monohydrogen phosphate, potassium chloride, monoammonium phosphate, potassium nitrate, potassium sulfate, potassium phosphite, ammonium phosphate and potassium tripolyphosphate.

[0014] Preferably, the synergist comprises one or more of molasses fermentation powder, fish protein powder, alginic acid, algae extract, chitosan oligosaccharide, γ-polyglutamic acid, γ-aminobutyric acid and polysaccharide polypeptide.

[0015] Preferably, the binder includes one or more of attapulgite, bentonite and plant glue powder.

[0016] The present invention also provides a method for preparing the composite microbial fertilizer described in the above technical solution, comprising the following steps:

[0017] The composite microbial fertilizer is obtained by mixing potassium humate, potassium fulvic acid, a large amount of elements, bacterial agents, slow-release silicon, sodium selenite, a synergist and a binder.

[0018] Preferably, after the mixing, the mixed material is mixed with water until the water content is 1.5-2.5wt% and then granulated to obtain a granular composite microbial fertilizer.

[0019] The present invention also provides the use of the composite microbial fertilizer described in the above technical solution or the composite microbial fertilizer prepared by the preparation method described in the above technical solution in one or more of enhancing crop stress resistance, increasing crop yield, improving crop quality and improving soil structure.

[0020] Beneficial effects:

[0021] The present invention provides a composite microbial fertilizer, comprising the following raw materials in parts by weight: 150-300 parts of potassium humate, 10-30 parts of potassium fulvic acid, 100-400 parts of macroelements, 10-50 parts of bacterial agents, 150-450 parts of slow-release silicon, 0.02-0.1 parts of sodium selenite, 2-10 parts of synergists and 50-150 parts of binders; the bacterial agents include Bacillus albus, arbuscular mycorrhizal fungi and Bacillus subtilis. The present invention uses potassium fulvic acid, bacterial agents, slow-release silicon and sodium selenite as stress-resistant core substances, supplemented by humic acid, macroelements and synergist substances, and the substances interact with each other to meet the fertilizer requirement of crops, effectively balance the nutrition of crops, and on the basis of improving the stress resistance of crops, it also has the functions of improving soil structure, increasing crop yield and improving crop quality. DETAILED DESCRIPTION

[0022] The invention provides a composite microbial fertilizer, comprising the following raw materials in parts by weight: 150-300 parts of potassium humate, 10-30 parts of potassium fulvic acid, 100-400 parts of macroelements, 10-50 parts of bacterial agents, 150-450 parts of slow-release silicon, 0.02-0.1 parts of sodium selenite, 2-10 parts of synergist and 50-150 parts of binder;

[0023] The bacterial agents include Bacillus albus, arbuscular mycorrhizal fungi and Bacillus subtilis.

[0024] As an embodiment, the weight proportion of potassium humate in the composite microbial fertilizer of the present invention can be 180 to 280 parts; as another embodiment, the weight proportion of the potassium humate can be 200 to 240 parts; the potassium humate in the composite microbial fertilizer has the effect of increasing the soil organic matter content, improving the soil structure and increasing the soil's ability to retain water and fertilizer.

[0025] As an embodiment, the weight proportion of potassium humate in the composite microbial fertilizer of the present invention may be 15 to 25 parts; as another embodiment, the weight proportion of the potassium humate may be 18 to 22 parts; the potassium humate in the composite microbial fertilizer has the effect of improving the stress resistance of crops.

[0026] As an embodiment, the weight proportion of the macroelements in the composite microbial fertilizer of the present invention may be 150 to 300 parts; as another embodiment, the weight proportion of the macroelements may be 200 to 240 parts. As an embodiment, the macroelements may be derived from one or more of urea, ammonium sulfate, potassium dihydrogen phosphate, potassium monohydrogen phosphate, potassium chloride, monoammonium phosphate, potassium nitrate, potassium sulfate, potassium phosphite, ammonium phosphate and potassium tripolyphosphate; as another embodiment, when the macroelements are derived from a variety of substances, the weight ratio of the various substances is not particularly limited, and a conventional combination is sufficient. The macroelements of the present invention have the function of providing the essential elements required for crop growth in the composite microbial fertilizer.

[0027] As an embodiment, the weight portion of the bacterial agent in the composite microbial fertilizer of the present invention can be 20 to 40 parts; as another embodiment, the weight portion of the bacterial agent can be 25 to 35 parts. As an embodiment, the mass portion of the Bacillus alexii in the bacterial agent of the present invention can be 5 to 20 parts, the mass portion of the arbuscular mycorrhizal fungi can be 3 to 30 parts, and the mass portion of the Bacillus subtilis can be 1 to 5 parts; as another embodiment, the mass portion of the Bacillus alexii in the bacterial agent can be 10 to 15 parts, the mass portion of the arbuscular mycorrhizal fungi can be 10 to 20 parts, and the mass portion of the Bacillus subtilis can be 2 to 4 parts. As an embodiment, the effective live bacterial concentrations of the arbuscular mycorrhizal fungi, Bacillus subtilis and Bacillus alexii can be 40 billion / g to 80 billion / g, respectively. The present invention has no special restrictions on the strain types of the Bacillus alfa, arbuscular mycorrhizal fungi and Bacillus subtilis, and any conventional strains of Bacillus alfa, arbuscular mycorrhizal fungi and Bacillus subtilis in the art can be used. After the arbuscular mycorrhizal fungi of the present invention infect the root system of crops, the crops can increase the absorption of nutrients in the soil through the fungal hyphae to promote the growth and development of the plants and improve the stress resistance of the plants; Bacillus alfa can degrade slow-release silicon into monosilicic acid that is directly absorbed and utilized by the crops, which is beneficial to improving the stress resistance of the crops; the Bacillus subtilis has the function of decomposing organic matter in the soil.

[0028] As an embodiment, the weight proportion of the slow-release silicon in the composite microbial fertilizer of the present invention may be 200 to 350 parts; as another embodiment, the weight proportion of the silicate may be 250 to 300 parts.

[0029] As an embodiment, the preparation method of the slow-release silicon of the present invention comprises: mixing silicate with water under stirring conditions until completely dissolved to obtain a 10% dilute silicate solution; removing metal cations in the 10% dilute silicate solution to obtain a dilute monosilicic acid solution; drying the dilute monosilicic acid solution to obtain slow-release silicon. As an embodiment, the stirring speed of the present invention can be 100-200r / min; the stirring time can be 0.5-1h. As an embodiment, the method of removing metal cations in the 10% dilute silicate solution of the present invention comprises: passing the 10% dilute silicate solution through a strongly acidic cation exchange resin, and keeping the pH value of the filtrate <3 to obtain a dilute monosilicic acid solution. As an embodiment, the silicate of the present invention can be but not limited to sodium silicate. As an embodiment, the drying method of the present invention can be spray drying; as another embodiment, the present invention can be spray dried by a spray dryer, and the specific parameters are not particularly limited, and the spray drying is performed until the dilute monosilicic acid solution is dried and dehydrated. As an embodiment, when the pH value is higher than 3, the pH value of the filtrate is ensured to be less than 3 by replacing the strongly acidic cation exchange resin.

[0030] The present invention adopts an ion exchange method to produce monosilicic acid. A sodium silicate solution diluted to a certain mass concentration is passed through a cation exchange resin at a certain flow rate to remove metal cations such as sodium in the dilute sodium silicate solution to obtain a monosilicic acid solution. The monosilicic acid solution is then dehydrated and dried using a spray dryer to obtain a slow-release silicon powder - polysilicic acid. The slow-release silicon powder prepared after dehydrating the monosilicic acid slowly releases monosilicic acid in the soil. Compared with silicon-containing minerals present in the soil, the slow-release silicon is more easily activated and degraded by the efficient silicon-degrading strain Bacillus aeruginosa into monosilicic acid that is directly absorbed and utilized by crops. It has a high utilization rate and is environmentally friendly. After being absorbed by crops, the deposition of monosilicic acid in the phloem can reduce Na + transported to the xylem, thereby reducing Na + The silicon fertilizer is transferred upward, alleviating the salt stress of crops. After crops absorb silicon fertilizer, the vascular bundles in the stems become thicker, the tissues become firmer, the stems become stronger, the lodging resistance is improved, and hard silicified cells are formed on the epidermis, reducing cracking and bacterial infection, and enhancing the crop's resistance to diseases and pests.

[0031] As an embodiment, the weight percentage of sodium selenite in the composite microbial fertilizer of the present invention can be 0.04-0.08 parts; as another embodiment, the weight percentage of sodium selenite can be 0.05-0.07 parts. In the present invention, selenium fertilizer can alleviate the adverse effects of different environmental stresses such as heavy metal stress, temperature stress, drought and salt stress, and the interaction between selenium fertilizer and the slow-release silicon in the above scheme helps to increase crop yield and quality, resist lodging, and is better than the single application of silicon fertilizer or the single application of selenium fertilizer.

[0032] As an embodiment, the weight proportion of the synergist in the composite microbial fertilizer of the present invention can be 4 to 8 parts of the synergist; as another embodiment, the weight proportion of the synergist can be 5 to 7 parts of the synergist. As an embodiment, the synergist of the present invention includes one or more of molasses fermentation powder, fish protein powder, alginic acid, seaweed essence, chitosan oligosaccharide, γ-polyglutamic acid, γ-aminobutyric acid and polysaccharide polypeptide; when the synergist includes several substances, the weight ratio of the several substances is not particularly limited, and a conventional combination is sufficient. The role of the synergist of the present invention in the composite microbial fertilizer is to promote the absorption of nutrients by crops.

[0033] As an embodiment, the weight proportion of the binder in the composite microbial fertilizer of the present invention may be 70 to 120 parts of the binder; as another embodiment, the weight proportion of the binder may be 80 to 110 parts. As an embodiment, the binder may include one or more of attapulgite, bentonite and plant glue powder; when the binder includes several substances, the weight ratio of the several substances is not particularly limited, and a conventional combination is sufficient. The role of the binder in the composite microbial fertilizer of the present invention is to promote the physical molding of the composite microbial fertilizer.

[0034] Unless otherwise specified, the present invention has no special limitation on the sources of the raw materials in the composite microbial fertilizer, and the corresponding raw materials obtained from conventional commercial channels in the art may be used.

[0035] The present invention also provides a method for preparing the composite microbial fertilizer described in the above technical solution, comprising the following steps:

[0036] The composite microbial fertilizer is obtained by mixing potassium humate, potassium fulvic acid, a large amount of elements, bacterial agents, slow-release silicon, sodium selenite, a synergist and a binder.

[0037] As an embodiment, the preparation method of the present invention further comprises, after the mixing, mixing the mixed material with water until the water content of the mixed material is 1.5-2.5wt%, and then granulating to obtain a granular composite microbial fertilizer. As an embodiment, the present invention sequentially puts potassium humate, potassium humate, a large amount of elements, bacterial agents, slow-release silicon, sodium selenite, synergist and binder into a fertilizer granulation mixer, and adjusts the water content of the mixed material to 1.5-2.5wt% and stirs for 0.5h until the mixture is uniform. As an embodiment, the granulation method of the present invention can be roller extrusion granulation. As an embodiment, the present invention can also sieve the granulated granular composite microbial fertilizer after granulation to filter out fine powder.

[0038] The preparation method of the composite microbial fertilizer of the present invention is simple, quick and easy to use.

[0039] The composite microbial fertilizer of the present invention can alleviate the adverse effects of different environmental stresses such as heavy metal stress, temperature stress, drought and salt stress, so that crops can grow normally; at the same time, the composite microbial fertilizer can increase soil organic matter, delay the release of fertilizer nutrients in the soil, improve the utilization rate of fertilizer nutrients, and has a significant repair effect on acidified soil, sandy soil, organic salinized soil, etc.

[0040] Based on the above advantages, the present invention also provides the use of the composite microbial fertilizer described in the above technical solution or the composite microbial fertilizer prepared by the preparation method described in the above technical solution in one or more of enhancing crop stress resistance, increasing crop yield, improving crop quality and improving soil structure. As an embodiment, the stress resistance described in the present invention can be one or more of salt-alkali resistance, drought resistance, temperature stress resistance and heavy metal stress resistance; the improved soil structure can be to increase organic matter in the soil.

[0041] In order to further illustrate the present invention, the technical effects provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0042] Example 1

[0043] A composite microbial fertilizer and a preparation method thereof:

[0044] The compound microbial fertilizer is composed of the following raw materials in parts by weight:

[0045] 270 parts of potassium humate, 25 parts of potassium fulvic acid, 400 parts of macroelements (composed of 250 parts of ammonium sulfate, 100 parts of monoammonium phosphate and 50 parts of potassium sulfate), 22.5 parts of bacterial agents (composed of 10 parts of Bacillus alexander, 10 parts of arbuscular mycorrhizal fungi and 2.5 parts of Bacillus subtilis, wherein the effective live bacteria concentrations of arbuscular mycorrhizal fungi, Bacillus subtilis and Bacillus alexander are 40 billion / g, 80 billion / g and 60 billion / g respectively), 150 parts of slow-release silicon, 0.05 parts of sodium selenite, 8 parts of synergist (composed of 3 parts of γ-polyglutamic acid and 5 parts of polysaccharide polypeptide) and 127 parts of bentonite.

[0046] The preparation steps are as follows:

[0047] (1) 3050 parts of water were injected into a reaction kettle, stirring was started, and 305 parts of sodium silicate were added at a speed of 150 r / min. The mixture was stirred for 0.8 h until the sodium silicate was completely dissolved to obtain a 10% dilute sodium silicate solution;

[0048] (2) passing a 10% dilute sodium silicate solution through a strong acid cation exchange resin at a certain flow rate, always maintaining the pH of the filtrate less than 3, and removing the sodium ions through the exchange with the strong acid cation resin to obtain a dilute monosilicic acid solution;

[0049] (3) drying the dilute monosilicic acid solution by a spray dryer to obtain a solid slow-release silicon powder after the dilute monosilicic acid solution is dried and dehydrated;

[0050] (4) 270 parts of potassium humate, 25 parts of potassium fulvic acid, 250 parts of ammonium sulfate, 100 parts of monoammonium phosphate, 50 parts of potassium sulfate, 10 parts of Bacillus alexandrus, 10 parts of arbuscular mycorrhizal fungi, 2.5 parts of Bacillus subtilis, 150 parts of slow-release silicon powder, 0.05 parts of sodium selenite, 3 parts of γ-polyglutamic acid, 5 parts of polysaccharide polypeptide and 127 parts of bentonite are sequentially put into a fertilizer granulation mixer, water is added to make the water content of the material 2.5wt%, stirred for 0.5h until the mixture is uniform, and double-roll extrusion granulation is performed on the granulator, and fine powder is filtered out through a sieve to obtain a composite microbial fertilizer with a particle size of 2 to 4mm.

[0051] Comparative Example 1

[0052] A method for preparing a slow-release silicon fertilizer comprises the following steps:

[0053] (1) 3050 parts of water were injected into a reaction kettle, stirring was started, and 305 parts of sodium silicate were added at a speed of 150 r / min. The mixture was stirred for 0.8 h until the sodium silicate was completely dissolved to obtain a 10% dilute sodium silicate solution;

[0054] (2) passing a 10% dilute sodium silicate solution through a strong acid cation exchange resin at a certain flow rate, always maintaining the pH of the filtrate less than 3, and removing the sodium ions through the exchange with the strong acid cation resin to obtain a dilute monosilicic acid solution;

[0055] (3) Drying the dilute monosilicic acid solution by a spray dryer to obtain solid slow-release silicon powder, i.e., the slow-release silicon fertilizer, after the dilute monosilicic acid solution is dried and dehydrated.

[0056] Comparative Example 2

[0057] Humic acid carrier bacterial agent: Evenly mix 270 parts of potassium humate, 25 parts of potassium fulvic acid and 22.5 parts of bacterial agent (consisting of 10 parts of Bacillus alexander, 10 parts of arbuscular mycorrhizal fungi and 2.5 parts of Bacillus subtilis, wherein the effective live bacteria concentrations of arbuscular mycorrhizal fungi, Bacillus subtilis and Bacillus alexander are 40 billion / g, 80 billion / g and 60 billion / g, respectively).

[0058] With corn as the test object, an indoor simulation test was adopted, and the salt content in the soil for corn planting was 4%. Four groups were set in the indoor simulation test, and three biological replicates were set in each group. The four groups were respectively applied with the composite microbial fertilizer in Example 1, the silicon fertilizer in Comparative Example 1, the humic acid carrier bacterial agent in Comparative Example 2, and no fertilizer (control). The three fertilization groups were mixed with the soil at 3‰ of the soil weight before corn sowing, and the other conditions of the four groups were kept consistent. The stress resistance related indexes were measured on the 15th day after emergence, and the measurement results were the average values ​​of the three biological replicates, and the results are shown in Table 1.

[0059] Table 1 Differences in crop stress resistance between composite microbial fertilizer and conventional single dosage form in Example 1

[0060]

[0061]

[0062] It can be concluded from Table 1 that the present invention compares the crop stress resistance indicators such as antioxidant enzyme (POD enzyme, SOD enzyme) activity, cell membrane stability, root hydraulic conductivity, leaf water potential and biomass under saline-alkali stress conditions (soil salt content 4%) (Table 1). The results show that the composite microbial fertilizer prepared by the scheme of the present invention can achieve better effects than conventional single dosage forms and has obvious interactive effects.

[0063] Application Example 1

[0064] The composite microbial fertilizer prepared in Example 1 was applied to the following:

[0065] Experimental location: Hohhot City and Linghe County, Inner Mongolia Autonomous Region;

[0066] Test crops: corn (Deka 159);

[0067] Test soil: sandy soil;

[0068] Fertilizer application amount: 40kg / mu, 100kg / mu, 400kg / mu;

[0069] Implementation method: Before sowing corn, fertilizer is spread evenly and the soil is tilled once with a rotary tiller. Other management methods are the same as the local conventional management methods for corn.

[0070] Application Example 2

[0071] Corn was planted and fertilizer was applied in the manner described in Application Example 1. The fertilizer applied was cow dung at an application rate of 5000 kg / mu.

[0072] The monitoring results of the growth status and yield of corn in Application Examples 1 and 2 are recorded respectively. The results are shown in Table 2:

[0073] Table 2 Comparison of corn growth status monitoring and yield results in Application Examples 1 to 2

[0074]

[0075] Application Example 3

[0076] The composite microbial fertilizer prepared in Example 1 was applied to the following:

[0077] Experimental location: Zhoucun District, Zibo City, Shandong Province;

[0078] Test crops: peanut;

[0079] Test soil: Forest-returned-to-cultivated soil;

[0080] Fertilizer application rate: 22kg / mu, 44kg / mu, 88kg / mu;

[0081] Implementation method: Before sowing peanuts, fertilizer is spread evenly and the soil is tilled once with a rotary tiller. Other management methods are the same as the local conventional management methods for peanuts, and no irrigation is performed on the dry land during the entire process.

[0082] Application Example 4

[0083] An experiment was conducted in a 60-mu peanut field in Mengshui Town, Zhoucun District, Zibo City, Shandong Province. Four treatments were set up, and each treatment was repeated 3 times. Before peanut sowing, conventional organic fertilizer was spread on the soil surface at a rate of 500kg / mu, and a rotary tiller was used to till the soil. The insecticides, fungicides, herbicides and other nutrient fertilizers used during the experiment remained consistent.

[0084] The monitoring of the growth status and the yield calculation of peanuts in Application Example 3 and Application Example 4 are recorded respectively, and the results are shown in Table 3:

[0085] Table 3 Comparison of peanut growth status monitoring and yield results in Application Examples 3 to 4

[0086]

[0087] The above test results fully demonstrate that after applying the composite microbial fertilizer of the present invention, the growth and yield increase effects of two main food crops on sandy soil and land converted from forest to farmland are significantly improved.

[0088] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A composite microbial fertilizer, characterized in that: The invention comprises the following raw materials in parts by weight: 150-300 parts of potassium humate, 10-30 parts of potassium fulvic acid, 100-400 parts of macroelements, 10-50 parts of bacterial agents, 150-450 parts of slow-release silicon, 0.02-0.1 parts of sodium selenite, 2-10 parts of synergist and 50-150 parts of binder; The bacterial agents include Bacillus albus, arbuscular mycorrhizal fungi and Bacillus subtilis.

2. The composite microbial fertilizer according to claim 1, characterized in that: The method for preparing the slow-release silicon comprises: mixing silicate with water under stirring conditions until the silicate is completely dissolved to obtain a 10% dilute silicate solution; removing metal cations from the 10% dilute silicate solution to obtain a dilute monosilicic acid solution; The dilute monosilicic acid solution is dried to obtain slow-release silicon.

3. The composite microbial fertilizer according to claim 2, characterized in that: The method for removing metal cations in the 10% dilute silicate solution comprises: passing the 10% dilute silicate solution through a strongly acidic cation exchange resin and maintaining the pH value of the filtrate to be less than 3, to obtain a dilute monosilicic acid solution.

4. The composite microbial fertilizer according to claim 1, characterized in that: In parts by weight, the bacterial agent comprises 5 to 20 parts of Bacillus albus, 3 to 30 parts of arbuscular mycorrhizal fungi and 1 to 5 parts of Bacillus subtilis.

5. The composite microbial fertilizer according to claim 1, characterized in that: The macroelements are derived from one or more of urea, ammonium sulfate, potassium dihydrogen phosphate, potassium monohydrogen phosphate, potassium chloride, monoammonium phosphate, potassium nitrate, potassium sulfate, potassium phosphite, ammonium phosphate and potassium tripolyphosphate.

6. The composite microbial fertilizer according to claim 1, characterized in that: The synergist comprises one or more of molasses fermentation powder, fish protein powder, alginic acid, algae extract, chitosan oligosaccharide, γ-polyglutamic acid, γ-aminobutyric acid and polysaccharide polypeptide.

7. The composite microbial fertilizer according to claim 1, characterized in that: The binder includes one or more of attapulgite, bentonite and plant glue powder.

8. The method for preparing the composite microbial fertilizer according to any one of claims 1 to 7, characterized in that: The steps include: The composite microbial fertilizer is obtained by mixing potassium humate, potassium fulvic acid, a large amount of elements, bacterial agents, slow-release silicon, sodium selenite, a synergist and a binder.

9. The preparation method according to claim 8, characterized in that: After the mixing, the mixed material is mixed with water until the water content is 1.5-2.5wt% and then granulated to obtain a granular composite microbial fertilizer.

10. Use of the composite microbial fertilizer according to any one of claims 1 to 7 or the composite microbial fertilizer prepared by the preparation method according to claim 8 or 9 in one or more of enhancing crop stress resistance, increasing crop yield, improving crop quality and improving soil structure.

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