1. A preparation method of a soil improvement fertilizer for promoting the absorption of plant trace elements comprises the following steps of preparing raw materials of urban greening garbage, compressed dry residues of waste vegetable leaves in a vegetable market, dry residues after semi-fermentation of kitchen garbage, solid residues left after animal innocent treatment and urban human excrement fermented dry residues; the preparation method comprises the following steps:

1) mixing urban greening garbage, waste vegetable leaf compressed dry residues in vegetable markets and bacillus subtilis, performing semi-suspension fermentation, and cooling to obtain a semi-suspension fermentation solid raw material;

2) mixing the dry residue after the semi-fermentation of the kitchen waste with water, and sequentially performing enzymolysis by using alkaline protease and cellulase to obtain an enzymolysis kitchen waste feed liquid;

3) mixing solid slag left after animal innocent treatment with water, and carrying out enzymolysis by using alkaline protease to obtain an enzymolyzed innocent slag feed liquid;

4) mixing the kitchen waste liquid obtained in the step 3) and the harmless slag material liquid obtained in the step 4) with diatomite, and filtering to obtain kitchen waste filtrate after enzymolysis and kitchen waste filter residue after enzymolysis, and harmless slag material filtrate after enzymolysis and harmless slag material filter residue after enzymolysis;

5) adjusting the pH values of the kitchen waste filtrate obtained in the step 4) after enzymolysis and the harmless slag material filtrate obtained after enzymolysis to 3.5 to obtain a protected protein peptide solution;

6) mixing the trace elements with the protected protein peptide solution obtained in the step 5) to obtain a trace element complexing core material;

7) wrapping the outer layer of the microelement complex core material obtained in the step 6) with the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue to obtain a soil improvement fertilizer; the sequence of wrapping the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue serving as outer layers is not limited;

there is no chronological definition between the steps 1), 2) and 3).

2. The preparation method of claim 1, wherein in the step 1), the mass ratio of the urban greening garbage to the compressed dry residue of the waste vegetable leaves in the vegetable market is (15-18): (3-6).

3. The preparation method according to claim 1, wherein the semi-suspension fermentation in step 1) is performed for 6-16 h at 36-52 ℃, and the temperature is raised to 80 ℃ and kept for 30 min; before the semi-suspension fermentation, the humidity of the material is controlled to be 30-35%, and after the semi-suspension fermentation, the humidity of the material is controlled to be 5-10%.

4. The method according to claim 1, wherein the alkaline protease is added in an amount of 0.05 to 0.2% and the activity is 20 ten thousand U/g, respectively; the addition amount of the cellulase is 0.1-0.3%, and the activity is 10 ten thousand U/g.

5. The preparation method according to claim 1, wherein in the step 4), the ratio of the added mass of the diatomite to the volume of the kitchen waste liquid after enzymolysis or the harmless slag liquid after enzymolysis is 3-12 g/L.

6. The method of claim 1, wherein the trace elements of step 6) include calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate, and copper sulfate.

7. The preparation method according to claim 1, wherein the mass ratio of the total mass of the trace elements in the step 6) to the mass of the protected protein peptide solution is (3-6): (45-70); the trace elements comprise the following components in parts by mass: 8-10 parts of calcium sulfate, 12-15 parts of magnesium sulfate, 1-3 parts of ammonium molybdate, 3-8 parts of sodium octaborate, 5-8 parts of zinc sulfate, 8-12 parts of ferrous sulfate and 2-3 parts of copper sulfate.

8. The preparation method according to claim 1, wherein in the step 7), the mass ratio of the total mass of the semi-suspended fermented solid raw material, the enzymatically hydrolyzed kitchen waste filter residue, the enzymatically hydrolyzed harmless slag material filter residue and the urban human excrement fermented dry residue to the trace element complexing core material is (40-58): (6-13).

9. The preparation method according to claim 1, wherein in the step 7), the mass ratio of the semi-suspended fermented solid raw material, the kitchen waste filter residue after enzymolysis, the harmless slag residue after enzymolysis and the urban human excrement fermented dry residue is (20-35): (5-10): (3-8): (10-12).

10. A soil improvement fertilizer prepared by the preparation method of any one of claims 1 to 9.

Background

The soil environment for crop growth is complex, and has various major elements, some medium elements and trace elements. The elements exist in the soil in the form of salt, some elements can be dissolved in water, some elements cannot be dissolved in water easily, and the growth of plants is closely related to the chemical components, types and contents of the elements. Furthermore, plants require these elements, but plants are not acceptable in any form, for example, plants require nitrogen, and can absorb urea or ammonium nitrate, but cannot absorb nitrogen. In addition, some elements are dissolved by underground water or rainwater after being released into soil through the fertilizer and are absorbed by plant roots, but some elements such as calcium and magnesium are likely to form insoluble substances when meeting the conditions of carbonate and the like during water dissolution, so that the insoluble substances are left in the soil and are not absorbed by plants, and the fertilizer utilization rate is low.

In the prior art, the chelated trace element fertilizer or the complexed trace element fertilizer is prepared in a direct combination mode, so that the water solubility is improved, but the loss speed is increased, the fertilizers are applied in a water-soluble fertilizer mode, the using amount is small, the fertilizers need to be applied for multiple times, the workload is large, and the field operation difficulty is large.

Disclosure of Invention

The invention aims to provide a soil improvement fertilizer for promoting the absorption of trace elements of plants and a preparation method thereof. The method of the invention improves the absorption of the trace elements by the plants by adjusting the combination state of the trace elements in the soil and adopting a post-organic chelation or complexation mode. The fertilizer prepared by the preparation method has a slow release effect and a good trace element absorption effect.

The invention provides a preparation method of a soil improvement fertilizer for promoting plant trace element absorption, wherein raw materials for preparing the soil improvement fertilizer comprise urban greening garbage, compressed dry residue of waste vegetable leaves in vegetable markets, dry residue after semi-fermentation of kitchen waste, solid residue left after harmless treatment of animals and urban human excrement fermented dry residue; the preparation method comprises the following steps:

1) mixing urban greening garbage, waste vegetable leaf compressed dry residues in vegetable markets and bacillus subtilis, performing semi-suspension fermentation, and cooling to obtain a semi-suspension fermentation solid raw material;

2) mixing the dry residue after the semi-fermentation of the kitchen waste with water, and sequentially performing enzymolysis by using alkaline protease and cellulase to obtain an enzymolysis kitchen waste feed liquid;

3) mixing solid slag left after animal innocent treatment with water, and carrying out enzymolysis by using alkaline protease to obtain an enzymolyzed innocent slag feed liquid;

4) mixing the kitchen waste liquid obtained in the step 3) and the harmless slag material liquid obtained in the step 4) with diatomite, and filtering to obtain kitchen waste filtrate after enzymolysis and kitchen waste filter residue after enzymolysis, and harmless slag material filtrate after enzymolysis and harmless slag material filter residue after enzymolysis;

5) adjusting the pH values of the kitchen waste filtrate obtained in the step 4) after enzymolysis and the harmless slag material filtrate obtained after enzymolysis to 3.5 to obtain a protected protein peptide solution;

6) mixing the trace elements with the protected protein peptide solution obtained in the step 5) to obtain a trace element complexing core material;

7) wrapping the outer layer of the microelement complex core material obtained in the step 6) with the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue to obtain a soil improvement fertilizer; the sequence of wrapping the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue serving as outer layers is not limited;

there is no chronological definition between the steps 1), 2) and 3).

Preferably, in the step 1), the mass ratio of the urban greening garbage to the compressed dry residue of the waste vegetable leaves in the vegetable market is (15-18): (3-6).

Preferably, the semi-suspension fermentation in the step 1) is performed for 6-16 h at 36-52 ℃, and the temperature is increased to 80 ℃ and kept for 30 min; before the semi-suspension fermentation, the humidity of the material is controlled to be 30-35%, and after the semi-suspension fermentation, the humidity of the material is controlled to be 5-10%.

Preferably, the addition amount of the alkaline protease is 0.05-0.2% respectively, and the activity is 20 ten thousand U/g respectively; the addition amount of the cellulase is 0.1-0.3%, and the activity is 10 ten thousand U/g.

Preferably, in the step 4), the ratio of the added mass of the diatomite to the volume of the kitchen waste material liquid after enzymolysis or the harmless slag material liquid after enzymolysis is 3-12 g/L.

Preferably, the trace elements of step 6) include calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate and copper sulfate.

Preferably, the mass ratio of the total mass of the trace elements in the step 6) to the protected protein peptide solution is (3-6): (45-70); the trace elements comprise the following components in parts by mass: 8-10 parts of calcium sulfate, 12-15 parts of magnesium sulfate, 1-3 parts of ammonium molybdate, 3-8 parts of sodium octaborate, 5-8 parts of zinc sulfate, 8-12 parts of ferrous sulfate and 2-3 parts of copper sulfate.

Preferably, in the step 7), the mass ratio of the total mass of the semi-suspended fermented solid raw materials, the enzymatically hydrolyzed kitchen waste filter residues, the enzymatically hydrolyzed harmless residue filter residues and the urban human excrement fermented dry residues to the trace element complexing core material is (40-58): (6-13).

Preferably, in the step 7), the mass ratio of the semi-suspended fermented solid raw materials, the enzymatically hydrolyzed kitchen waste filter residues, the enzymatically hydrolyzed harmless slag material filter residues and the urban human excrement fermented dry residues is (20-35): (5-10): (3-8): (10-12).

The invention also provides the soil improvement fertilizer prepared by the preparation method of the technical scheme.

The invention provides a preparation method of a soil improvement fertilizer for promoting trace element absorption of plants. On the basis of the traditional organic fertilizer slow release principle, the solid trace element chelating and complexing organic fertilizer is prepared by selecting the chelating and complexing functions of specific protein peptides and combining the organic fertilizer slow release principle. The chelating and complexing function of the fertilizer is that protein peptide contained in organic fertilizer (urban human excrement fermented dry residue) enters soil and is released after contacting with underground water or rainwater, and the protein peptide is quickly chelated or complexed with trace elements in the fertilizer and supplied to plants for absorption. The fertilizer prepared by the method can realize the following four functions, namely the release of protein, the chelation (complexation) of trace elements, the ventilation and water absorption of the porous organic fertilizer, and the slow release effect caused by compression and water absorption. The soil improvement fertilizer prepared by the preparation method solves the problem that the combined trace element chelated fertilizer is fast in loss, and the slow release time is changed from one time of spraying 7 days of the water soluble fertilizer to 1-3 months of slow release after the solid organic soil improvement fertilizer is used; the invention also solves the problem that the trace elements of the fertilizer are easy to salinize and not absorbed, and the content of the trace elements in the soil is obviously increased after the fertilizer is used; the invention provides a novel utilization scheme of various urban garbage, and compared with the existing organic fertilizer prepared by singly using garbage, the organic fertilizer has richer fertilizer efficiency and higher fertilizer efficiency; the invention adopts the organic fertilizer as the foundation, the application amount of the fertilizer in the soil is reduced, and the organic matters in the soil are continuously increased.

Detailed Description

The invention provides a preparation method of a soil improvement fertilizer for promoting plant trace element absorption, wherein raw materials for preparing the soil improvement fertilizer comprise urban greening garbage, compressed dry residue of waste vegetable leaves in vegetable markets, dry residue after semi-fermentation of kitchen waste, solid residue left after harmless treatment of animals and urban human excrement fermented dry residue;

the invention adopts urban greening garbage, dry residue after semi-fermentation of kitchen garbage, compressed dry residue of waste vegetable leaves in vegetable market, solid residue left after harmless treatment of animals and urban human excrement fermented dry residue as raw materials; providing an amino acid source by using dry residues obtained by semi-fermentation of kitchen waste, and extracting polysaccharides and protein peptides from the dry residues by a biological enzymolysis method; extracting animal source protein peptide from solid slag after animal innocent treatment; preparing the urban greening garbage and the waste vegetable leaf dry residue into a slow-release breathable water-absorbing basic carrier mainly by an air semi-suspension fermentation method; the final assembly of the organic fertilizer is completed by a specific sequence mixing and pressing wrapping technology, so that the trace elements are not chelated or complexed with protein peptides in the fertilizer too much before being released, the self-stable chemical combination state is still kept, and the protein is not deteriorated and consumed due to wrapping.

The preparation method comprises the following steps:

1) mixing urban greening garbage, waste vegetable leaf compressed dry residues in vegetable markets and bacillus subtilis, performing semi-suspension fermentation, and cooling to obtain a semi-suspension fermentation solid raw material;

2) mixing the dry residue after the semi-fermentation of the kitchen waste with water, and sequentially performing enzymolysis by using alkaline protease and cellulase to obtain an enzymolysis kitchen waste feed liquid;

3) mixing solid slag left after animal innocent treatment with water, and carrying out enzymolysis by using alkaline protease to obtain an enzymolyzed innocent slag feed liquid;

4) mixing the kitchen waste liquid obtained in the step 3) and the harmless slag material liquid obtained in the step 4) with diatomite, and filtering to obtain kitchen waste filtrate after enzymolysis and kitchen waste filter residue after enzymolysis, and harmless slag material filtrate after enzymolysis and harmless slag material filter residue after enzymolysis;

5) adjusting the pH values of the kitchen waste filtrate obtained in the step 4) after enzymolysis and the harmless slag material filtrate obtained after enzymolysis to 3.5 to obtain a protected protein peptide solution;

6) mixing the trace elements with the protected protein peptide solution obtained in the step 5) to obtain a trace element complexing core material;

7) wrapping the outer layer of the microelement complex core material obtained in the step 6) with the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue to obtain a soil improvement fertilizer; the sequence of wrapping the semi-suspended fermented solid raw material obtained in the step 1), the kitchen waste filter residue obtained in the step 4) after enzymolysis, the harmless slag material filter residue obtained in the step 4) after enzymolysis and the urban human excrement fermented dry residue serving as outer layers is not limited;

there is no chronological definition between the steps 1), 2) and 3).

In the present invention, the municipal waste preferably comprises leaves and/or branches. The leaves or branches of the present invention include dry or wet leaves or branches. The urban greening garbage is preferably crushed, and the particle size after crushing is preferably 0.5-1.5 mm, so that semi-suspension fermentation of the urban greening garbage is facilitated. The method of the pulverization in the present invention is not particularly limited, and the pulverization may be carried out by using a conventional wood pulverizer well known to those skilled in the art.

In the invention, the compressed dry residues of the abandoned vegetable leaves in the vegetable market are preferably dropped or selected from the vegetable market, and the residual dry matters are physically squeezed to obtain the residual dry matters containing a large amount of cellulose and other substances with the water content of preferably 30-40%, the water content is high and difficult to crush, the water content is low, the average efficiency of the existing squeezing equipment is 30-65% of water residue, and the water content of 30-40% is selected, so that the post-treatment is facilitated. In the invention, the particle size of the compressed dry residue of the waste vegetable leaves in the vegetable market is preferably 0.5-1 mm.

In the invention, the semi-fermented dry residue of the kitchen waste is the residual semi-fermented dry residue of the kitchen waste after primary fermentation treatment, namely the waste after municipal kitchen waste treatment. In the invention, most of salt in the kitchen waste flows out along with water generated by primary fermentation (the water usually reaches the discharge standard after anaerobic and aerobic treatment), grease is also provided, the semi-fermented dry residue is obtained by squeezing and is rich in amino acid and protein generated by fermentation, and the waste is usually buried or burned. The method preferably crushes the semi-fermented dry residues, and the crushed dry residues are preferably sieved by a 40-60-mesh sieve, so that subsequent enzymolysis treatment is facilitated.

The solid slag material left after the animal innocent treatment comprises bone slag and minced meat, wherein the bone slag and the minced meat are preferably mixed with water with the mass of 0.6-1.5 times and then stirred into a slurry shape.

The urban human excrement fermented dry residue comprises fermented and well-cooked human excrement dry residue, and the water content is preferably 20-25%. The urban human excrement fermentation dry residue is preferably crushed, and the particle size after crushing is preferably 40-60 meshes. The method of pulverization in the present invention is not particularly limited, and a conventional pulverization method known to those skilled in the art may be employed. The aperture of the human excrement fermented dry residue is various and loose, and the human excrement fermented dry residue is used as a solid carrier of the fertilizer and can supplement nutrient sources of nitrogen elements and carbon elements.

Mixing urban greening garbage, waste vegetable leaf compressed dry residues in vegetable markets and bacillus subtilis, performing semi-suspension fermentation, and cooling to obtain a semi-suspension fermentation solid raw material. In the invention, the mass ratio of the urban greening garbage to the compressed dry residue of the waste vegetable leaves in the vegetable market is preferably (15-18): (3-6), the setting of the mass ratio can realize the control of the moisture and improve the fermentation effect. In the invention, the inoculation amount of the bacillus subtilis is preferably 0.3-1% by mass percentage, and more preferably 0.5%. In the present invention, the concentration of Bacillus subtilis for inoculation is preferably 1.6X 10⁸cfu/mL. The inoculation condition is set, so that the cost is low, the fermentation speed and efficiency can be ensured, and the problem of abnormal smell or harmful substances caused by uncontrolled fermentation due to improper quantity of engineering bacteria can be avoided. When urban greening garbage, waste vegetable leaf compressed dry residues in vegetable markets and bacillus subtilis are mixed, water is preferably added, and the humidity of the material is adjusted, namely the humidity of the material is controlled to be 30-35% before semi-suspension fermentation. In the invention, the semi-suspension fermentation condition is preferably 36-52 ℃ for 6-16 h, the temperature is increased to 80 ℃ and is kept for 30min, and more preferably 42 ℃ is kept for 30min after 8h of fermentation. The limitation of the semi-suspension fermentation condition can accelerate the exchange of substances and the mobility of microorganisms among solid materials, thereby improving the fermentation speed and the control effect of the solid raw materials. The semi-suspension fermentation according to the invention is preferably carried out in a suspension apparatus, more preferably in a suspension tank. The invention preferably uses compressed air and a stirring paddle to stir materials uniformly to form a semi-suspension state in the tank, the compressed air can ensure that a certain amount of gas is filled between the materials to ensure that the materials form an aerosol state and roll mutually under the push of the compressed air, the compressed air has a certain temperature and can supply the materialsHeating the material, keeping the temperature or reducing the temperature, and simultaneously providing oxygen required by aerobic fermentation. The compressed air can be provided by combining an air compressor and an air storage tank, the flow rate and the flow speed of the air are controlled, and the air is dispersed in the materials, so that the materials can be subjected to air floatation fermentation. After the temperature of the material is kept at 80 ℃ for 30min, the temperature of blown compressed air is preferably adjusted, the heating of the tank is stopped, the material is gradually cooled and air-dried to the normal temperature, namely after semi-suspension fermentation, the humidity of the material is controlled to be 5-10%. In the invention, the normal temperature is preferably 20-25 ℃.

According to the invention, dry residue obtained after semi-fermentation of kitchen waste is mixed with water, and enzymolysis is carried out by using alkaline protease and cellulase in sequence to obtain kitchen waste feed liquid after enzymolysis. According to different dietary differences of different places, the main components of the kitchen waste are slightly different, if complex enzyme is selected according to actual conditions, the adjustment complexity is large, the kitchen waste treatment control is complex, and the cost is high. In the invention, the mass ratio of the dry residue after the semi-fermentation of the kitchen waste to the water is preferably (0.5-1.2): 1, more preferably 1: 1. According to the invention, after the dry residue of semi-fermented kitchen garbage is mixed with water, the temperature is preferably adjusted to 50-60 ℃, and the constant temperature is kept for 10 min. After the constant temperature is kept, the pH value is preferably adjusted to 7.5-8.5, the reagent for adjusting the pH value is not particularly limited, and a conventional reagent for adjusting the pH value, such as sodium hydroxide, which is well known to a person skilled in the art can be adopted. After the pH value is adjusted according to the invention, alkaline protease is preferably added. In the invention, the addition amount of the alkaline protease is preferably 0.05-0.2%, more preferably 0.15%, and the activity is preferably 20 ten thousand U/g; the time for enzymolysis of the dry residue after semi-fermentation of the kitchen waste by using the alkaline protease is preferably 0.8-2 hours, more preferably 1 hour, and the enzymolysis is constant-temperature enzymolysis. After the alkaline protease is used for enzymolysis, the invention preferably uses cellulase for enzymolysis, in the invention, the addition amount of the cellulase is preferably 0.1-0.3%, more preferably 0.2%, and the activity is preferably 10 ten thousand U/g. In the invention, the enzymolysis time by using cellulase is preferably 1-2 h, more preferably 1h, and the enzymolysis is constant-temperature enzymolysis. The setting of the enzymolysis conditions can quickly extract the nutrient substances in the enzymolysis solution, simplify and improve the process flow and operability, and reduce the industrialization cost and the management cost.

The invention mixes the solid slag material left after the animal innocent treatment with water, and carries out enzymolysis by using alkaline protease to obtain the innocent slag material liquid after the enzymolysis. The invention mixes the solid slag left after the animal innocent treatment with water to obtain the innocent slag slurry. The mass ratio of the solid slag material left after the animal innocent treatment to the water is preferably 1: (1-2.5). The method preferably heats the harmless slag feed liquid to 50-60 ℃, keeps the temperature for 10min, then adjusts the pH value to 7.5-8.5, and then adds alkaline protease for enzymolysis. In the present invention, the amount of the alkaline protease added is preferably 0.05 to 0.2%, more preferably 0.15%, and the activity is preferably 20 ten thousand U/g. The pH adjusting agent used in the present invention is not particularly limited, and a conventional pH adjusting agent known to those skilled in the art, such as sodium hydroxide, may be used. The limit of the enzymolysis conditions can realize the industrial and more stable enzymolysis of the solid slag.

After obtaining the kitchen waste liquid after enzymolysis and the harmless slag material liquid after enzymolysis, the invention respectively mixes the kitchen waste liquid after enzymolysis and the harmless slag material liquid after enzymolysis with diatomite and filters to obtain kitchen waste filtrate after enzymolysis and kitchen waste filter residue after enzymolysis as well as harmless slag material filtrate after enzymolysis and harmless slag material filter residue after enzymolysis. The diatomite is added to assist in filtration, so that the situation that viscous substances or other substances in an enzymolysis product block a filter medium (filter cloth or a ceramic filter element) quickly in filtration is avoided, and meanwhile, the diatomite can adsorb partial impurities in liquid. In the invention, the ratio of the added mass of the diatomite to the volume of the kitchen waste liquid after enzymolysis or the harmless slag material liquid after enzymolysis is preferably 3-12 g/L, and more preferably 4.5 g/L. The limit of the addition amount of the diatomite can realize better filter aid effect, excessive diatomite addition cannot help filtration but easily blocks a filter medium, and excessive diatomite addition cannot achieve the filter aid effect, so that partial slag can leak through the filter medium, and the filter fails. After the mixing, the present invention is preferably stirred uniformly. The filtering is preferably plate-and-frame filtering, and the enzymatic kitchen waste filter residue and the enzymatic harmless slag charge filter residue obtained by filtering are preferably respectively pressed under pressure until the water content is 5-10%. Then crushing the mixture for later use.

After obtaining the kitchen waste filtrate after enzymolysis and the harmless slag material filtrate after enzymolysis, the pH of the kitchen waste filtrate after enzymolysis and the harmless slag material filtrate after enzymolysis are adjusted to 3.5 to obtain the protected protein peptide solution. In the present invention, the pH is preferably adjusted by using acetic acid or hydrochloric acid, and after the pH is adjusted, the mixture is preferably stirred uniformly. The pH of the solution of the invention is limited so that the solution of the invention comprising amino acids and protein peptides is not susceptible to the growth of bacteria and other microorganisms and is not viable even if contaminated with small amounts of microorganisms.

The invention mixes the trace elements with the protected protein peptide solution to obtain the trace element complexing core material. In the present invention, the trace elements preferably include calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate, and copper sulfate. In the invention, the mass ratio of the total mass of the trace elements to the protected protein peptide solution is preferably (3-6): (45-70), more preferably 5.6: 57; the trace elements preferably comprise the following components in parts by mass: 8-10 parts of calcium sulfate, 12-15 parts of magnesium sulfate, 1-3 parts of ammonium molybdate, 3-8 parts of sodium octaborate, 5-8 parts of zinc sulfate, 8-12 parts of ferrous sulfate and 2-3 parts of copper sulfate. In general, if a plurality of trace elements are mixed in water, a composite antagonistic condition is easily formed, and a water-insoluble crystalline substance is generated, so that the water-soluble fertilizer or the liquid fertilizer fails. Meanwhile, the trace elements are absorbed by plants, and are generally carried out in an ionic state through water as a medium. Therefore, once a plurality of trace elements form a condition of antagonistic coagulation, the trace elements are difficult to be absorbed by plants, and most of chemical fertilizers and a part of water-soluble fertilizers are in the soil or the surface of the plants, which is a problem, so that the absorption rate of the plants is low, and the salinization and hardening of the soil are aggravated. The invention utilizes the complexation (including partial chelation) of fresh enzymolysis amino acid and protein small peptide molecules on trace elements to lead the originally antagonistic trace element ions to be wrapped and separated by the amino acid or protein peptide, thereby achieving the condition of stable coexistence in liquid. Meanwhile, due to the complexing effect of amino acid state or protein peptide, the plant can absorb the trace elements more easily, thereby promoting the effect stability of the fertilizer. However, because the protein peptide or the amino acid is easily decomposed under the action of microorganisms, after stable amino acid or protein peptide complexation (namely protected protein peptide solution) is achieved, the trace elements are mixed with the protected protein peptide solution to prepare a trace element complexation core material, then the pelleting technology is utilized, different solid organic fertilizer powder (semi-suspension fermentation solid raw materials, kitchen garbage filter residues after enzymolysis, harmless residue filter residues after enzymolysis and urban human excrement fermentation dry residues) are used as wrapping materials by one layer, the core material is sealed, the moisture in the core material is further drained, so that the moisture of the whole organic fertilizer particles is not more than 7%, and meanwhile, the normal storage water absorption rate is low, so that the protein peptide and the amino acid in the core material are protected from being decomposed by the microorganisms. On the other hand, due to the adoption of a multi-layer coating and granulating process, the organic fertilizer particles are compact in structure, have a certain slow release effect after entering soil, can have a slow release time of 4-6 months under the normal rainwater condition, and have continuous and stable fertility. Compared with the soil quality of common organic fertilizer, the soil quality preserving time is longer and the effect is better.

After the trace element complexing core material is obtained, the invention wraps the upper half of the layer of the trace element complexing core material with semi-suspended fermented solid raw materials, kitchen garbage filter residues after enzymolysis, harmless residue filter residues after enzymolysis and urban human excrement fermented dry residues to obtain the soil improvement fertilizer; the sequence of wrapping the semi-suspended fermented solid raw materials, the enzymatically hydrolyzed kitchen waste filter residues, the enzymatically hydrolyzed harmless residue filter residues and the urban human excrement fermented dry residues as outer layers is not limited. The invention mixes protein peptide and microelements into the interior, the exterior is gradually wrapped by solid powdery material to form a layer-by-layer wrapping mode, the decomposition of the protein peptide in the interior is slowed down due to the drying of the material, and meanwhile, the multi-layer structure can form a slow release effect. For example, calcium ions and magnesium ions are easy to crystallize in water to generate a hardly-soluble stone structure, and amino acid calcium or protein peptide calcium, amino acid magnesium or protein peptide magnesium is formed by utilizing the complexing effect of protein peptide and amino acid. In the invention, the mass ratio of the total mass of the semi-suspended fermentation solid raw material, the kitchen waste filter residue after enzymolysis, the harmless slag material filter residue after enzymolysis and the urban human excrement fermentation dry residue to the microelement complex core material is preferably (40-58): (6-13). In the invention, the mass ratio of the semi-suspended fermentation solid raw material, the kitchen garbage filter residue after enzymolysis, the harmless slag residue after enzymolysis and the urban human excrement fermentation dry residue is preferably (20-35): (5-10): (3-8): (10-12), more preferably 24:7:3: 12. In the present invention, the mixing is further preferably: mixing the trace element complexing core material with one of semi-suspended fermented solid raw materials, kitchen waste filter residues after enzymolysis, harmless residue filter residues after enzymolysis and urban human excrement fermented dry residues, granulating to obtain a first mixture, mixing the first mixture with one of the rest three raw materials, granulating to obtain a second mixture, mixing the second mixture with one of the rest two raw materials, granulating to obtain a third mixture, and mixing the third mixture with the last raw material and granulating. In the present invention, it is preferable to stir the mixture uniformly. The invention uses the fermented dry residues of the urban human excrement as the coarse powder bearing agent, so that the mixed wrapping material is embedded into the gaps of the bearing agent, thereby facilitating granulation plasticity. According to the invention, the protein peptide in the interior is low in water content, relatively closed and not easy to decompose and degrade by wrapping layer by layer, the total water content is not more than 7%, and the protein peptide is in a relatively stable state. Meanwhile, the structure of the layer-by-layer wrapping is beneficial to slow release of organic fertilizer in soil, the nutrient release is stable and uniform, the organic fertilizer is not easy to be taken away by rainwater quickly, a slow release period of 4-6 months can be realized in the soil, organic components such as protein peptide and amino acid and complex trace elements exist, and under the layer-by-layer wrapping process, the content of the effective components of the protein peptide and the amino acid is still over 75% after the soil improvement fertilizer is naturally stored for 6-8 months. If a multilayer wrapping process is not used, the content of effective protein peptide or amino acid in the prepared organic fertilizer is reduced by about 50 percent after 1 month by using a simple mixed extrusion process, and the requirement of wide application cannot be met.

After the soil organic fertilizer is obtained, the organic fertilizer is preferably pressed, more preferably, a heating granulator is used for pressing, and the organic fertilizer is preferably pressed into particles with the particle size of 2-3 mm. The moisture content of the granules according to the invention is preferably not more than 7%. After the granules are produced, the double-layer sealed packaging bag is preferably used for packaging, and the finished product is integrated.

The invention also provides the soil improvement fertilizer prepared by the preparation method of the technical scheme.

The soil improvement fertilizer for promoting the absorption of plant trace elements and the preparation method thereof are further described in detail with reference to the following specific examples, and the technical scheme of the invention includes but is not limited to the following examples.

Example 1

1. Pretreatment of raw materials:

urban greening garbage: the green garbage is crushed into wood powder and wood chips with the average size of 0.5mm, so that the subsequent semi-suspension fermentation is facilitated;

compressed dry residue of waste vegetable leaves in the vegetable market: crushing the raw material vegetable leaf dry residue into 0.5mm fragments by using a crusher;

dry residue after semi-fermentation of kitchen waste: crushing the residual semi-fermented dry residue after the kitchen waste treatment into 40-60-mesh fragments, so as to facilitate the next enzymolysis treatment;

solid slag left after animal innocent treatment: adding 1 time of water by mass and stirring into slurry;

fermentation dry residue of urban human feces: beating the mixture into powder of 40-60 meshes by a crusher to serve as a solid bearing agent;

2. semi-suspension fermentation: adding green garbage scraps and vegetable leaf scraps into a suspension tank, and adding a bacillus subtilis strain mother liquor (1.6 multiplied by 10) with the mass of 0.5 percent of the solid raw material⁸cfu/mL) and proper water, adjusting the humidity of the materials to 30%, uniformly stirring the scraps by using compressed air and a stirring paddle, forming a semi-suspension state in a tank, fermenting for 10 hours at a constant temperature of 45 ℃, and then heating to 80 ℃ for 30 min; adjusting the temperature of the blown compressed air, stopping heating the tank, gradually cooling the materials, and air-drying to normal temperature, wherein the moisture is controlled to be about 6 percent, and completing fermentation;

3. enzymolysis of dry residues of kitchen garbage: adding water with the mass of 1 time of that of the kitchen garbage dry residue fragments into the kitchen garbage dry residue fragments, heating the mixture to 53 ℃, keeping the temperature for 10min, then adding proper sodium hydroxide to adjust the pH value to 7.5, adding 0.1% of alkaline protease, and carrying out enzymolysis for 1h at the constant temperature; then adding 0.1% of cellulase, and carrying out enzymolysis for 1h at constant temperature;

4. carrying out enzymolysis on harmless slag materials: heating the harmless slag slurry to 52 ℃, keeping the temperature for 10min, adding proper sodium hydroxide to adjust the pH value to 7.5, adding 0.1% of alkaline protease, and carrying out enzymolysis for 2h at the constant temperature;

5. and (3) filtering: respectively adding 4.5g/L of diatomite into the feed liquid obtained after the enzymolysis in the steps 3 and 4, uniformly stirring, carrying out plate-frame filtration, pressing solid filter residues into a semi-dry state (with the water content of 5%) under pressure, and crushing for later use;

6. protein peptide protection: adding acetic acid into the filtrate obtained in the step 5, adjusting the pH value to 3.5, uniformly stirring, and performing protein peptide protection;

7. mixed package 1: adding trace element compounds (calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate and copper sulfate) into the protein peptide concentrated solution protected in the step 6, and uniformly stirring, wherein the mass ratio of the trace element compounds to the protected protein peptide concentrated solution is 3 g: continuously stirring and complexing for 30min to obtain a trace element complexing core material, then uniformly mixing and stirring the trace element complexing core material and the slag after the semi-suspension fermentation in the step 2, and granulating; the mass ratio of the trace element complexing core material to the slag material after semi-suspension fermentation in the step 2, the harmless dry slag filtered in the step 5, the kitchen garbage dry slag filtered in the step 5 and the human excrement dry slag coarse powder carrier is 12: 25: 6.25: 3.75: 12; the sequence of wrapping the slag after the semi-suspension fermentation in the step 2, the harmless dry slag after the filtration in the step 5, the kitchen garbage dry slag after the filtration in the step 5 and the human excrement dry slag coarse powder carrier can be changed;

8. and (3) mixed packaging 2: adding the harmless dry slag filtered in the step 5 into the powder prepared in the step 7, uniformly stirring, and performing wrapping granulation;

9. and (3) mixed wrapping: adding the kitchen garbage dry residue filtered in the step 5 into the powder prepared in the step 8, uniformly stirring, and performing wrapping granulation;

10. carrying: and (4) adding a human excrement dry slag coarse powder carrying agent into the powder mixed and wrapped in the step (9), so that the mixed wrapping material is embedded into pore-size gaps of the carrying agent, and granulation and shaping are facilitated.

11. And (3) adjusting and granulating: after layer-by-layer wrapping granulation, finally extruding the mixture to prepare particles (the water content is less than 7%) with the particle size of 2-3 mm in a heating granulation mode;

12. packaging: and packaging the manufactured particles in a double-layer sealed package bag to form an integrated finished product.

13. In the semi-suspension fermentation solid raw material of the method: 15 parts of urban greening garbage scraps and 4 parts of vegetable leaf dry residues;

14. the method comprises the following steps: 250kg of semi-suspended fermented dry residue, 62.5kg of vegetable market waste vegetable leaf compressed dry residue, 37.5kg of solid residue left after animal innocent treatment and 120kg of human excrement fermented dry residue;

15. the activity of the alkaline protease is 20 ten thousand U/g, and the activity of the cellulase is 10 ten thousand U/g;

the trace element compound comprises the following components: 2kg of calcium sulfate, 3kg of magnesium sulfate, 0.25kg of ammonium molybdate, 0.75kg of sodium octaborate, 1.25kg of zinc sulfate, 2kg of ferrous sulfate and 0.5kg of copper sulfate.

Example 2

1. Pretreatment of raw materials:

urban greening garbage: the greening garbage is crushed into wood powder and wood chips with the average size of 1mm, so that the subsequent semi-suspension fermentation is facilitated;

compressed dry residue of waste vegetable leaves in the vegetable market: crushing the dry vegetable leaf residues into 1mm fragments by using a crusher;

dry residue after semi-fermentation of kitchen waste: crushing the dry kitchen waste residue into 60-mesh fragments, so as to facilitate the next enzymolysis treatment;

solid slag left after animal innocent treatment: mainly comprising bone dregs and minced meat, adding water with the mass of 1.5 times of the bone dregs and the minced meat and stirring the mixture into slurry;

fermentation dry residue of urban human feces: beating the mixture into powder of 40-60 meshes by a crusher to serve as a solid bearing agent;

2. semi-suspension fermentation: adding green garbage scraps and vegetable leaf scraps into a suspension tank, and adding a bacillus subtilis strain mother liquor (1.6 multiplied by 10) with the mass of 0.5 percent of the solid raw material⁸cfu/mL) and proper water, adjusting the humidity of the materials to 35%, uniformly stirring the scraps by using compressed air and a stirring paddle, forming a semi-suspension state in a tank, fermenting for 8 hours at a constant temperature of 52 ℃, and then heating to 80 ℃ for 30 min; adjusting the temperature of the blown compressed air, stopping heating the tank, gradually cooling the materials, and air-drying to normal temperature, controlling the water content to 7 percent, and finishing fermentation;

3. enzymolysis of dry residues of kitchen garbage: adding 1 time of water by mass into the kitchen garbage dry residue fragments, heating to 55 ℃, keeping the temperature for 10min, then adding proper sodium hydroxide to adjust the pH value to 8, adding 1.5% of alkaline protease, and carrying out enzymolysis for 1h at constant temperature; then adding 0.2% of cellulase, and carrying out enzymolysis for 1h at constant temperature;

4. carrying out enzymolysis on harmless slag materials: heating the harmless slag slurry to 55 ℃, keeping the temperature constant for 10min, adding proper sodium hydroxide to adjust the pH value to 8.5, adding 1.5% of alkaline protease, and carrying out enzymolysis for 2h at the constant temperature;

5. and (3) filtering: respectively adding 4.5g/L of diatomite into the feed liquid obtained after the enzymolysis in the steps 3 and 4, uniformly stirring, carrying out plate-frame filtration, pressing solid filter residues into a semi-dry state (the water content is 8%) under pressure, and crushing for later use;

6. protein peptide protection: adding acetic acid or acetic acid into the filtrate obtained in the step 5, adjusting the pH value to 3.5, uniformly stirring, and performing protein peptide protection;

7. mixed package 1: adding trace element compounds (calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate and copper sulfate) into the protein peptide concentrated solution protected in the step 6, and uniformly stirring, wherein the mass ratio of the trace element compounds to the protected protein peptide concentrated solution is 5 g: 55g, continuously stirring and complexing for 30min to obtain a trace element complexing core material, then uniformly mixing and stirring the trace element complexing core material with the slag after the semi-suspension fermentation in the step 2, and granulating; the mass ratio of the trace element complexing core material to the slag material after semi-suspension fermentation in the step 2, the harmless dry slag filtered in the step 5, the kitchen garbage dry slag filtered in the step 5 and the human excrement dry slag coarse powder carrier is 13: 28: 7: 5: 11; the sequence of wrapping the slag after the semi-suspension fermentation in the step 2, the harmless dry slag after the filtration in the step 5, the kitchen garbage dry slag after the filtration in the step 5 and the human excrement dry slag coarse powder carrier can be changed;

8. and (3) mixed packaging 2: adding the harmless dry slag filtered in the step 5 into the powder prepared in the step 7, uniformly stirring, and performing wrapping granulation;

9. and (3) mixed wrapping: adding the kitchen garbage dry residue filtered in the step 5 into the powder prepared in the step 8, uniformly stirring, and performing wrapping granulation;

10. carrying: and (4) adding a human excrement dry slag coarse powder carrying agent into the powder mixed and wrapped in the step (9), so that the mixed wrapping material is embedded into pore-size gaps of the carrying agent, and granulation and shaping are facilitated.

11. And (3) adjusting and granulating: after layer-by-layer wrapping granulation, finally extruding the mixture to prepare particles (the water content is less than 7%) with the particle size of 2-3 mm in a heating granulation mode;

12. packaging: and packaging the manufactured particles in a double-layer sealed package bag to form an integrated finished product.

13. In the semi-suspension fermentation solid raw material of the method: 16 parts of urban greening garbage scraps and 4 parts of vegetable leaf dry residues;

14. the method comprises the following steps: 280kg of semi-suspension fermented dry residue, 70kg of vegetable market waste vegetable leaf compressed dry residue, 50kg of solid residue left after animal innocent treatment and 110kg of human excrement fermented dry residue;

15. the activity of the alkaline protease is 20 ten thousand U/g, and the activity of the cellulase is 10 ten thousand U/g;

the trace element compound comprises the following components: 1.75kg of calcium sulfate, 3.25kg of magnesium sulfate, 0.5kg of ammonium molybdate, 1kg of sodium octaborate, 1.5kg of zinc sulfate, 2.5kg of ferrous sulfate and 0.5kg of copper sulfate.

Example 3

1. Pretreatment of raw materials:

urban greening garbage: smashing the green waste into wood powder and wood chips with the average size of 1.5mm so as to facilitate subsequent semi-suspension fermentation;

compressed dry residue of waste vegetable leaves in the vegetable market: crushing into 1mm chips by using a crusher;

dry residue after semi-fermentation of kitchen waste: crushing the dry kitchen waste residue into 60-mesh fragments, so as to facilitate the next enzymolysis treatment;

solid slag left after animal innocent treatment: mainly comprising bone dregs and minced meat, adding water with the mass of 1.5 times of the bone dregs and the minced meat and stirring the mixture into slurry;

fermentation dry residue of urban human feces: beating the mixture into powder of 40-60 meshes by a crusher to serve as a solid bearing agent;

2. semi-suspension fermentation: adding green garbage scraps and vegetable leaf scraps into a suspension tank, and adding a bacillus subtilis strain mother liquor (1.6 multiplied by 10) with the mass of 0.5 percent of the solid raw material⁸cfu/mL) and proper water, adjusting the humidity of the materials to 35%, uniformly stirring the scraps by using compressed air and a stirring paddle, forming a semi-suspension state in a tank, fermenting for 14 hours at a constant temperature of 52 ℃, and then heating to 80 ℃ for 30 min; adjusting the temperature of the blown compressed air, stopping heating the tank, gradually cooling the materials, and air-drying to normal temperature, controlling the water content to 10 percent, and finishing fermentation;

3. enzymolysis of dry residues of kitchen garbage: adding 1 time of water by mass into the kitchen waste dry residue fragments, heating to 50-60 ℃, keeping the temperature for 10min, then adding appropriate sodium hydroxide to adjust the pH value to 8.5, adding 0.2% of alkaline protease, and carrying out enzymolysis for 1h at the constant temperature; then adding 0.3% of cellulase, and carrying out enzymolysis for 1h at constant temperature;

4. carrying out enzymolysis on harmless slag materials: heating the harmless slag slurry to 58 ℃, keeping the temperature for 10min, adding proper sodium hydroxide to adjust the pH value to 8.5, adding 0.2% of alkaline protease, and carrying out enzymolysis for 2h at the constant temperature;

5. and (3) filtering: respectively adding 4.5g/L of diatomite into the feed liquid obtained after the enzymolysis in the steps 3 and 4, uniformly stirring, carrying out plate-frame filtration, pressing solid filter residues into a semi-dry state (the water content is 8%) under pressure, and crushing for later use;

6. protein peptide protection: adding acetic acid or acetic acid into the filtrate obtained in the step 5, adjusting the pH value to 3.5, uniformly stirring, and performing protein peptide protection;

7. mixed package 1: adding trace element compounds (calcium sulfate, magnesium sulfate, ammonium molybdate, sodium octaborate, zinc sulfate, ferrous sulfate and copper sulfate) into the protein peptide concentrated solution protected in the step 6, and uniformly stirring, wherein the mass ratio of the trace element compounds to the protected protein peptide concentrated solution is 6 g: 70g, continuously stirring and complexing for 30min to obtain a trace element complexing core material, then uniformly mixing and stirring the trace element complexing core material with the slag after the semi-suspension fermentation in the step 2, and granulating; the mass ratio of the trace element complexing core material to the slag material after semi-suspension fermentation in the step 2, the harmless dry slag filtered in the step 5, the kitchen garbage dry slag filtered in the step 5 and the human excrement dry slag coarse powder carrier is 10: 28: 6.4: 6.4: 10.6; the sequence of wrapping the slag after the semi-suspension fermentation in the step 2, the harmless dry slag after the filtration in the step 5, the kitchen garbage dry slag after the filtration in the step 5 and the human excrement dry slag coarse powder carrier can be changed;

8. and (3) mixed packaging 2: adding the harmless dry slag filtered in the step 5 into the powder prepared in the step 7, uniformly stirring, and performing wrapping granulation;

9. and (3) mixed wrapping: adding the kitchen garbage dry residue filtered in the step 5 into the powder prepared in the step 8, uniformly stirring, and performing wrapping granulation;

10. carrying: adding a human excrement dry slag coarse powder carrying agent into the powder mixed and wrapped in the step 9, so that the mixed wrapping material is embedded into pore-size gaps of the carrying agent, and granulation and shaping are facilitated;

11. and (3) adjusting and granulating: after layer-by-layer wrapping granulation, finally extruding the mixture to prepare particles (the water content is less than 7%) with the particle size of 2-3 mm in a heating granulation mode;

12. packaging: and packaging the manufactured particles in a double-layer sealed package bag to form an integrated finished product.

13. In the semi-suspension fermentation solid raw material of the method: 18 parts of urban greening garbage scraps and 5 parts of vegetable leaf dry residues;

14. the method comprises the following steps: 280kg of semi-suspension fermented dry residue, 64kg of vegetable market waste vegetable leaf compressed dry residue, 64kg of solid residue left after animal innocent treatment and 106kg of human excrement fermented dry residue;

15. the activity of the alkaline protease is 20 ten thousand U/g, and the activity of the cellulase is 10 ten thousand U/g;

the trace element compound comprises the following components: 2.5kg of calcium sulfate, 3.75kg of magnesium sulfate, 0.75kg of ammonium molybdate, 1.75kg of sodium octaborate, 1.5kg of zinc sulfate, 2.5kg of ferrous sulfate and 0.5kg of copper sulfate.

Example 4

According to the organic fertilizer industry standard 'NY 525 + 2012 standard', sampling detection is carried out on the organic fertilizer produced in the three examples by using a soil fertilizer nutrient speed tester EK-CT04, and the obtained results are shown in tables 1-3:

table 1 example 1 product sample test results

Table 2 example 2 product sample test results

Serial number	Detecting items	Unit of	The result of the detection	Upper limit of detection	Judgment of
						1	Nitrogen is present in	％	13.15	0.5<N<1.0	Is higher than the original
2	Phosphorus (P)	％	7.528	0.5<P2O5<1.0	Is higher than the original
						3	Potassium salt	％	17.23	0.6<K2O<1.8	Is higher than the original
4	Organic matter	％	77.1	≧45	Is higher than the original
						5	Moisture content	％	29	≦30	Conform to

Table 3 example 3 product sample test results

Serial number	Detecting items	Unit of	The result of the detection	Upper limit of detection	Judgment of
						1	Nitrogen is present in	％	15.06	0.5<N<1.0	Is higher than the original
2	Phosphorus (P)	％	9.335	0.5<P2O5<1.0	Is higher than the original
						3	Potassium salt	％	19.17	0.6<K2O<1.8	Is higher than the original
4	Organic matter	％	77.6	≧45	Is higher than the original
						5	Moisture content	％	30	≦30	Conform to

According to the detection result, the organic matter content of the soil improvement fertilizer produced by the invention far exceeds the national standard, and the soil improvement fertilizer is a high-quality solid organic fertilizer, can be used for fields, is rich in nutrition and is a high-quality organic fertilizer.

Tracking and testing the use effect of the farmland: the soil trace elements were measured before application and 1 month, 3 months and 6 months after application of each example sample, and the results are shown in table 4:

TABLE 4 soil microelement status

From the data in table 4, it can be seen that the amount of the trace elements in the soil is obviously increased after the adjustment of the trace elements in the soil is performed, and meanwhile, most of the supplemented trace elements can be effectively absorbed and utilized through cultivation for a period of time, so that the compound fertilizer has obvious effects on the nutrient recovery of the soil and the establishment of a compound nutrient system compared with the existing compound fertilizer containing no trace elements. Meanwhile, the fertilizer is also a powerful supplement for trace element fertilizers on the leaf surfaces, is more beneficial to the continuous growth of plants and is beneficial to the restoration of a soil nutrient system.

The products and semi-finished products (trace element compounds, the protein peptide concentrated solution protected in the step 6, the slag after semi-suspension fermentation in the step 2, the harmless dry slag filtered in the step 5, the kitchen garbage dry slag filtered in the step 5 and the human excrement dry slag crude powder carrying agent) in the examples 1 and 2 are respectively sampled for effect test in a mixing mode, the semi-finished product raw materials in the method examples 1 and 2 are respectively and directly mixed and stirred into loose powdery organic fertilizer 10g and respectively recorded as a sample 1 and a sample 2, meanwhile, the finished product granular organic fertilizer products 10g in the examples 1 and 2 are recorded as a sample 3 and a sample 4 and are bagged for 3 days, 7 days and 14 days at room temperature, and the protein peptide content in the leachate of the samples is respectively tested. The results are shown in Table 5.

TABLE 5 detection of protein peptide content in extract of organic fertilizer sample

	Sample 1	Sample 2	Sample 3	Sample No. 4
					Before placing	19.4％	20.2％	19.6％	21％
Standing for 3 days	17.1％	17.9％	19.4％	20.7％
					Standing for 7 days	15.8％	16.1％	19.2％	20.5％
Standing for 14 days	10.5％	11.0％	19.1％	20.3％

The comparison shows that the loss and the loss of the protein peptide in the layer-by-layer coated and compacted granular organic fertilizer are slow, the granular organic fertilizer is suitable for being slowly released in soil, and meanwhile, the granular organic fertilizer can be transported in length, so that the effectiveness of the organic fertilizer is guaranteed.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.