Carbon sequestration and nitrogen conservation biological organic fertilizer and preparation method thereof

Abstract

The invention belongs to the technical field of biological fertilizers, and particularly provides a carbon sequestration and nitrogen conservation biological organic fertilizer and a preparation method thereof.Molybdenum, copper, cobalt and composite flora are loaded on biomass charcoal to prepare load type biomass charcoal; and jointly preparing the supported biomass charcoal, the perilla biomass extracting solution and animal waste into the biological organic fertilizer. According to the biological organic fertilizer provided by the invention, unnecessary waste of strain resources can be avoided, and the organic fertilizer can remarkably promote the immobilization effect of soil on ammonium nitrogen and nitrate nitrogen; the compound bacteria liquid promotes decomposition of organic matters and effectiveness of nutrients, and promotes improvement of soil, so that improvement of soil productivity is facilitated; meanwhile, the organic fertilizer can obviously improve the enzyme activity of the soil and promote the improvement of the fertility of the soil, so that the effect of conditioning the soil is finally realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological fertilizers, and in particular, relates to a carbon-fixing and nitrogen-retaining biological organic fertilizer and a preparation method thereof. Background Art

[0002] For a long time, the rapid development of agriculture, excessive application of chemical fertilizers, unreasonable farming methods, etc. have led to an imbalance in the soil carbon and nitrogen cycle. Excessive application of chemical fertilizers has caused large-scale pollution of soil and groundwater, reduced the quality of agricultural products, and increased greenhouse gas emissions. As people pay more attention to food safety and ecological environment, green food and organic agriculture have developed rapidly.

[0003] Bio-organic fertilizer is a compound fertilizer of microorganisms with specific functions and harmlessly treated livestock and poultry manure, crop straw, and decomposed organic materials. It has the dual effects of microbial fertilizer and organic fertilizer. Bio-organic fertilizer is rich in organic carbon. The application of bio-organic fertilizer can increase the input of organic carbon in the soil, promote the accumulation of soil organic carbon, and improve the soil's carbon fixation capacity. By optimizing the return of straw and animal organic fertilizer to the field, reducing the easily decomposable carbon content in organic materials and increasing the difficult-to-decompose carbon content, methane emissions can be effectively controlled and the soil's carbon fixation effect can be improved. The nitrogen in bio-organic fertilizer mainly exists in an organic state. After being applied to the soil, it is gradually released through the decomposition of microorganisms, which can provide crops with a continuous and stable nitrogen supply and reduce nitrogen losses.

[0004] However, the nutrient content of existing bio-organic fertilizers is relatively low, and the nutrient release rate and utilization rate are not ideal. Therefore, it is an urgent practical need to further increase the nutrient content in bio-organic fertilizers to better meet the growth needs of crops. The existing bio-organic fertilizers have low carbon fixation efficiency. Screening and cultivating more efficient carbon-fixing and nitrogen-retaining microbial strains, adding them to bio-organic fertilizers, increasing the activity and number of microorganisms in the soil, and thus improving the carbon-fixing and nitrogen-retaining capacity of bio-organic fertilizers are important development directions in the field of bio-fertilizer technology. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a carbon-fixing and nitrogen-retaining biological organic fertilizer and a preparation method thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions: The present invention provides a method for preparing a carbon-fixing and nitrogen-retaining biological organic fertilizer, comprising the following steps: (1) crushing corn stalks and polyvinyl alcohol resin by weight, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, drying them, placing the dried mixture in a carbonization furnace, and carbonizing them under a nitrogen atmosphere to obtain activated biomass charcoal; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, stirring the mixture for 2-4 hours, and grinding the mixture to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with a composite bacterial solution, and stirring for 1-2 hours to obtain modified biochar, wherein the composite bacterial solution is obtained by mixing azotobacter nitrogen-fixing bacteria, Pantoea anacardiae and Aspergillus niger solution; (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, stirring and reacting for 1-2 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure are fully mixed, stirred for 20-30 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0007] Furthermore, in step (1), the mass ratio of corn stalks to polyvinyl alcohol resin is 100:(1-10), and the carbonization temperature is 700-800°C.

[0008] Furthermore, in step (2), the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:(0.01-0.2), and the stirring time is 2 hours.

[0009] Furthermore, in step (3), the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomata and Aspergillus niger is 2:(1-2):(1-2), and the total mass of the bacteria in the composite bacterial solution is 2-30% of the mass of the hierarchical pore structure product prepared in step (2).

[0010] Furthermore, the method for preparing the perilla biomass extract in step (5) comprises: adding perilla to water and stirring for 10 minutes, and heat-treating the obtained juice for 2-3 hours at a heat treatment temperature of 80-120° C. to obtain the perilla biomass extract.

[0011] Furthermore, 5-60 grams of perilla are added to every 1L of water.

[0012] Furthermore, in step (4), the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:(0.05-0.2):(0.05-0.2).

[0013] Furthermore, in step (5), the mass ratio of the supported biochar, the perilla biomass extract and the animal feces is 1:(10-100):(10-100).

[0014] The present invention selects potassium hydroxide and potassium carbonate as activators to activate corn stalks and polyvinyl alcohol resins rich in oxygen-containing functional groups to prepare activated biochar. Compared with other conventionally selected activators such as sodium hydroxide, potassium hydroxide and potassium carbonate jointly activate corn stalks and polyvinyl alcohol resins, which is more conducive to the load of strains in the composite bacterial liquid on biochar, improves the utilization efficiency of strains, and thus improves the carbon fixation and nitrogen retention capacity of the organic fertilizer finally prepared. Potassium hydroxide and potassium carbonate synergistically activate the biomass system composed of straw and polyvinyl alcohol resin, and can prepare biochar with a hierarchical pore structure, in which the large pores account for a large proportion, ensuring the high loading rate of subsequent strains on the surface of biochar, and appropriate metal cobalt complexes, metal molybdenum and copper complexes, and strains are all loaded in the corresponding pore structure, further improving the pore utilization efficiency in the biochar.

[0015] In the preparation process of the present invention, the composite bacterial community is first loaded onto the biochar and then the complex of metal molybdenum and copper is loaded. Since the molecular size of the complex of metal molybdenum and copper is much smaller than the size of the strains in the composite bacterial solution, the complex is combined with the active sites on the biochar formed between the strains, and the active sites on the biochar are fully utilized, thereby improving the utilization efficiency of the active sites in the biochar and ensuring the loading efficiency of the strains in the composite bacterial solution.

[0016] The present invention adopts brown spherical nitrogen-fixing bacteria, ananastomata and black Aspergillus as composite bacteria. In addition to the mutual cooperation between the self-generated nitrogen-fixing bacteria and the degrading bacteria, and the mutual provision of energy substances between the bacterial species, the intermediate product of a certain bacterial species may be more conducive to the degradation or nitrogen fixation of other bacterial species. Compared with the composite bacteria obtained by combining other bacterial species, the composite bacteria recorded in the present invention can make the organic fertilizer have better fertility, accelerate the nitrogen fixation process, and improve the nitrogen fixation efficiency.

[0017] The present invention adopts dicobalt ethylenediaminetetraacetate, tetraamminecopper sulfate and Mo-EDTA complex as precursors of metal components. Compared with metal inorganic salt components, low salinity of organic fertilizer can be ensured, thereby avoiding high mortality of beneficial soil bacteria. At the same time, the selection of Mo-EDTA complex can be used to provide high level of molybdenum to the surface of biochar in a stable liquid preparation.

[0018] The present invention uses perilla as the raw material of the biomass extract. First, perilla can be obtained in large quantities without special cultivation. Perilla also has a high nitrogen content. Compared with other plants, the nitrogen can be prepared through the biomass extract to have a high nitrogen recovery rate, and then introduced into the soil through the organic fertilizer of the present invention.

[0019] The invention also provides a carbon-fixing and nitrogen-retaining biological organic fertilizer prepared by the preparation method.

[0020] Beneficial effects of the present invention: 1. In the present invention, molybdenum, copper, cobalt and composite bacterial flora are loaded on biochar to prepare organic fertilizer, which can avoid unnecessary waste of bacterial resources, and the organic fertilizer can significantly promote the fixation of ammonium nitrogen and nitrate nitrogen in the soil.

[0021] 2. The present invention finds that by using brown spherical nitrogen-fixing bacteria, ananastomata and black Aspergillus as composite bacteria, in addition to the mutual synergy between spontaneous nitrogen-fixing bacteria and degrading bacteria, and the provision of energy substances between the species, the intermediate products of a certain species may be more conducive to the degradation or nitrogen fixation of other species. Compared with the composite bacteria obtained by combining other species, the composite bacteria recorded in the present invention can make the organic fertilizer have better fertility, accelerate the nitrogen fixation process, and improve the nitrogen fixation efficiency.

[0022] 3. The present invention uses corn stalks and polyvinyl alcohol resin as biomass raw materials to prepare biochar. After activation with potassium hydroxide and potassium carbonate, biochar with a spatial three-dimensional cross-linked structure can be prepared. The biochar forms a large number of small chambers, which are loaded with composite bacterial communities after oxidation. These composite bacterial communities reproduce in large numbers with the help of the heat preservation and moisture retention effects brought by the small chambers, thereby promoting the improvement of the fertility of organic fertilizers.

[0023] 4. The organic fertilizer in the present invention can increase the organic matter and nitrogen content of the soil, adjust the pH value, and the composite bacterial solution can promote the decomposition of organic matter and the effectiveness of nutrients, promote soil improvement, and thus facilitate the improvement of soil productivity; at the same time, the organic fertilizer can significantly increase the activity of soil enzymes, promote the improvement of soil fertility, and ultimately achieve the effect of soil conditioning. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Unless otherwise specified, the raw materials and equipment used in the embodiments of the present invention are raw materials and equipment from conventional sources in the art. The endpoints and any values ​​of the scope disclosed in this article are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article.

[0026] Example 1

[0027] A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin at a mass ratio of 100:1, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 700° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.01, stirring the reaction for 2 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1 hour to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1:1, and the total mass of the bacterial species in the composite bacterial solution is 2% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.05:0.05, and stirring the reaction for 1 hour to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:20:80, stirred for 20 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0028] The preparation method of the perilla biomass extract comprises: adding 5g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2h at a heat treatment temperature of 80°C to obtain the perilla biomass extract.

[0029] Example 2

[0030] A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:3, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 730° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.05, stirring the reaction for 2 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.2:1.2, and the total mass of the bacterial species in the composite bacterial solution is 10% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.08:0.08, and stirring the reaction for 1 hour to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:30:70, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0031] The preparation method of the perilla biomass extract comprises: adding 10g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0032] Example 3

[0033] A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0034] The preparation method of the perilla biomass extract comprises: adding 30g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0035] Example 4

[0036] A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:7, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 760° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.1, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing the brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of the brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.7:1.7, and the total mass of the bacterial species in the composite bacterial solution is 20% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.15:0.15, and stirring the mixture for 2 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:30:60, stirred for 30 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0037] The preparation method of the perilla biomass extract comprises: adding 40g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 100°C to obtain the perilla biomass extract.

[0038] Example 5 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:9, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 780° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.15, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 2 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.9:1.9, and the total mass of the bacterial species in the composite bacterial solution is 25% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.18:0.18, and stirring the mixture for 2 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:25:55, stirred for 30 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0039] The preparation method of the perilla biomass extract comprises: adding 50g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 3h at a heat treatment temperature of 100°C to obtain the perilla biomass extract.

[0040] Example 6 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:10, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 800° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.2, stirring the reaction for 4 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 2 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing the bacterial solutions of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:2:2, and the total mass of the bacterial species in the composite bacterial solution is 30% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.2:0.2, and stirring the mixture for 2 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:25:50, stirred for 30 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0041] The preparation method of the perilla biomass extract comprises: adding 60g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 3h at a heat treatment temperature of 110°C to obtain the perilla biomass extract.

[0042] Comparative Example 1 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing sodium carbonate and sodium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0043] The preparation method of the perilla biomass extract comprises: adding 30g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0044] Comparative Example 2 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing copper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, copper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0045] The preparation method of the perilla biomass extract comprises: adding 30g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0046] Comparative Example 3 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, Frankia and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, Frankia and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0047] The preparation method of the perilla biomass extract comprises: adding 30g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0048] Comparative Example 4 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, Bacillus subtilis and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, Bacillus subtilis and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0049] The preparation method of the perilla biomass extract comprises: adding 30g of perilla into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the perilla biomass extract.

[0050] Comparative Example 5 A carbon-fixing and nitrogen-retaining biological organic fertilizer is prepared by the following preparation method: (1) Weighing corn stalks and polyvinyl alcohol resin in a mass ratio of 100:5, crushing the corn stalks and the polyvinyl alcohol resin, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, and drying them. The dried mixture is placed in a carbonization furnace and carbonized at 750° C. under a nitrogen atmosphere to obtain activated biochar; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, wherein the mass ratio of the activated biochar to the dicobalt ethylenediaminetetraacetate in the mixed solution is 1:0.08, stirring the reaction for 3 hours, and grinding to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with the composite bacterial solution and stirring for 1.5 hours to obtain modified biochar; The composite bacterial solution is obtained by mixing brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger, wherein the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2:1.5:1.5, and the total mass of the bacterial species in the composite bacterial solution is 15% of the mass of the hierarchical pore structure product prepared in step (2); (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, wherein the mass ratio of the modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:0.1:0.1, and stirring the reaction for 1.5 hours to obtain a supported biochar; (5) The loaded biochar, nettle biomass extract and animal manure were fully mixed in a mass ratio of 1:40:60, stirred for 25 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

[0051] The preparation method of the nettle biomass extract comprises: adding 30g of nettle into 1L of water and stirring for 10min, heat-treating the obtained juice for 2.5h at a heat treatment temperature of 90°C to obtain the nettle biomass extract.

[0052] Application examples: This application example conducts the following tests on the carbon-fixing and nitrogen-retaining biological organic fertilizers prepared in Examples 1-6 and Comparative Examples 1-5: (1) Experimental plants: Cherry tomatoes, specifically the Millennium fruit variety.

[0053] (2) Experimental grouping: Use flower pots with a diameter of 15 cm and a height of 20 cm, put an appropriate amount of soil with basically the same physical and chemical characteristics in each flower pot, dig a hole of appropriate size in the flower pot, transplant the 12±1 cm cherry tomato seedlings with good growth into the flower pot, transplant one cherry tomato seedling in each flower pot, mix 120g of carbon-fixing and nitrogen-retaining biological organic fertilizer with an appropriate amount of soil, fill the flower pot, and compact lightly. The carbon-fixing and nitrogen-retaining biological organic fertilizers described in the above Examples 1-6 and Comparative Examples 1-5 were applied separately, and a total of 11 groups were set up, each group was set up with 5 parallels, and the average value of each test result was taken, and no chemical fertilizer was added throughout the process. Keep the daytime temperature at about 25°C and the night temperature at about 15°C, ensure 6-8 hours of light duration per day, keep the soil moist, and adjust the watering frequency according to the weather and soil moisture.

[0054] Analysis of cherry tomato plant growth: After cherry tomatoes were harvested, samples of each group of cherry tomato plants were collected to measure the aboveground fresh weight, aboveground plant height, and plant stem diameter of each pot of cherry tomato plants. The results are recorded in Table 1.

[0055] Measurement of the aboveground fresh weight of cherry tomatoes: Rinse the plants slowly with clean water, place them in a cool place to dry, measure the aboveground fresh weight of the plants using an electronic balance, record the aboveground fresh weight of each group of plants, and calculate the average value.

[0056] Measurement of the above-ground height of cherry tomatoes: Use a tape measure to measure the length from the root neck to the top, which is the above-ground plant height. Record the above-ground plant height of each group and calculate the average value.

[0057] Measurement of stem diameter of cherry tomato plants: Use a digital caliper to measure the diameter of the plant 1 cm below the cotyledons, which is the stem diameter of the plant. Record the stem diameter of each group of plants and calculate the average value.

[0058] Table 1 Effect of the carbon-fixing and nitrogen-retaining biological organic fertilizer of the present invention on the growth of cherry tomato plants

[0059] From the results in Table 1, we can see that: Comparison of Example 3 with Comparative Example 1 shows that the present invention selects potassium hydroxide and potassium carbonate as activators to activate corn stalks and polyvinyl alcohol resins rich in oxygen-containing functional groups to prepare activated biochar. Compared with sodium carbonate and sodium hydroxide as activators, potassium hydroxide and potassium carbonate jointly activate corn stalks and polyvinyl alcohol resins, which is more conducive to the load of strains in the composite bacterial liquid on biochar, improves the utilization efficiency of strains, and thus improves the carbon fixation and nitrogen retention capacity of the organic fertilizer finally prepared. Potassium hydroxide and potassium carbonate synergistically activate the biomass system composed of straw and polyvinyl alcohol resin, and can prepare biochar with a hierarchical pore structure, in which the large pores account for a large proportion, ensuring the high loading rate of subsequent strains on the surface of biochar, and appropriate metal cobalt complexes, metal molybdenum and copper complexes, and strains are all loaded in the corresponding pore structure, further improving the pore utilization efficiency in the biochar. In the preparation process of the present invention, the composite bacterial community is first loaded onto the biochar and then the metal molybdenum and copper complex is loaded. Since the molecular size of the metal molybdenum and copper complex is much smaller than the size of the strain in the composite bacterial solution, the complex is combined with the active sites formed between the strains on the biochar, and the active sites on the biochar are fully utilized, the utilization efficiency of the active sites in the biochar is improved, and the loading efficiency of the strains in the composite bacterial solution is guaranteed. By using potassium carbonate and potassium hydroxide as activators, the growth of the plant is better than that of sodium carbonate and sodium hydroxide as activators, and the aboveground fresh weight, aboveground plant height and plant stem thickness are increased to a certain extent, indicating that the biological organic fertilizer using potassium carbonate and potassium hydroxide as activators can better promote the growth of plants.

[0060] By comparing Example 3 with Comparative Example 2, it can be seen that the present invention uses dicobalt ethylenediaminetetraacetate, tetraamminecopper sulfate and Mo-EDTA complex as precursors of metal components, which can ensure the low salinity of organic fertilizer compared to metal inorganic salt components, thereby avoiding the high mortality rate of beneficial soil bacteria, thereby better promoting plant growth.

[0061] It can be seen from the comparison of Example 3 and Comparative Examples 3-4 that the present invention adopts brown ball nitrogen-fixing bacteria, pineapple pantoea and black Aspergillus as composite bacteria, in addition to playing the role of mutual coordination between spontaneous nitrogen-fixing bacteria and degradation bacteria, the species provide energy substances to each other, and the intermediate product of a certain species may be more conducive to the degradation or nitrogen fixation of other species. Compared with the composite bacteria obtained by other species combinations, the composite bacteria recorded in the present invention can make organic fertilizer have better fertility, accelerate the nitrogen fixation process, and improve nitrogen fixation efficiency. Therefore, the composite bacterial liquid selected by the present invention interacts with each other, better promotes the utilization rate of nutrients in organic fertilizer, and provides more abundant nutrition for plant growth.

[0062] It can be seen from the comparison between Example 3 and Comparative Example 5 that the perilla biomass extract obtained by using perilla as the raw material of the biomass extract in the present invention can better promote plant growth compared with other plant biomass extracts.

[0063] Analysis of soil physical and chemical indicators: After cherry tomatoes were harvested, 200 g of soil was collected from each flower pot to measure the soil moisture content, pH value, organic matter, and nitrogen content. The average value of each group was measured and the results are recorded in Table 2.

[0064] Soil moisture content determination and analysis method: Collect 20g of experimental soil sample, put it into a dry container, weigh it to obtain m1 grams, put the container with the collected soil sample into an oven, bake it until the weight no longer changes, take it out and weigh it to obtain m2 grams, and measure its moisture content.

[0065] Soil moisture calculation formula: W = (m1-m2) / (m2-m)*100%; W-soil moisture content; m-container (g); m1-weight of container and wet soil sample (g); m2-weight of container and dry soil sample (g).

[0066] Soil pH determination and analysis method: Take 10g soil sample, air-dry the soil sample and grind it through a 20-mesh sieve respectively. The soil pH is determined using a pH meter (Leci PHS-25), and the water-soil ratio is 2.5:1.

[0067] Soil organic matter content determination and analysis method: Take 0.5g of dried soil sample that has passed through a 100-mesh sieve, add 10mL of 1mol / L K2Cr2O7 aqueous solution to a 500mL conical flask, and shake gently to disperse the soil particles; add 10mL of concentrated sulfuric acid to the conical flask, shake well, and let stand for 30 minutes; then add 200mL of water and 4 drops of o-phenanthroline indicator to the conical flask, and finally titrate to the endpoint with 0.5mol / L FeSO4 standard solution, and do a blank determination at the same time, and record the low iron dosage. Soil organic matter is calculated according to the following formula: Soil organic matter g / kg = M (V0-V) × 0.0057 × 1.4 × 1000 / W M- molar concentration of standard low iron solution; V0-blank titration low iron solution volume, mL; V-volume of low iron solution used for sample titration, mL; W-dry soil weight, g.

[0068] Determination and analysis method of soil nitrogen content: Agricultural Industry Standard of the People's Republic of China - Organic Fertilizer (NY525-2012)).

[0069] Table 2 Effects of the carbon-fixing and nitrogen-retaining biological organic fertilizer of the present invention on soil physical and chemical indicators

[0070] It can be seen from Table 2 that: Comparison of Example 3 with Comparative Example 1 shows that the present invention selects potassium hydroxide and potassium carbonate as activators to activate corn stalks and polyvinyl alcohol resin rich in oxygen-containing functional groups to prepare activated biochar. Compared with using sodium carbonate and sodium hydroxide as activators, the soil organic matter and nitrogen content of the organic fertilizer applied are higher, and the carbon fixation and nitrogen retention capacity of the biological organic fertilizer is improved.

[0071] By comparing Example 3 with Comparative Example 2, it can be seen that the present invention uses dicobalt ethylenediaminetetraacetate, tetraamminecopper sulfate and Mo-EDTA complex as precursors of metal components, which can further improve the properties of the soil compared to the metal inorganic salt components, thereby better promoting the growth of plants.

[0072] It can be seen from the comparison of Example 3 and Comparative Examples 3-4 that the present invention adopts brown ball nitrogen-fixing bacteria, pineapple pantoea and black Aspergillus as composite bacteria, in addition to playing the role of mutual cooperation between spontaneous nitrogen-fixing bacteria and degradation bacteria, and providing energy substances between strains, the intermediate product of a certain strain may be more conducive to the degradation or nitrogen fixation of other strains, compared with the composite bacteria obtained by other strain combinations, the composite bacteria recorded in the present invention can make organic fertilizer have better fertility, accelerate the nitrogen fixation process, and improve nitrogen fixation efficiency. Therefore, the composite bacterial liquid selected by the present invention interacts with each other, increases the water retention of the soil, improves the physical and chemical properties of the soil, makes the soil more loose and fertile, and therefore, is more conducive to the growth of plants.

[0073] By comparing Example 3 with Comparative Example 5, it can be seen that the present invention uses perilla as the raw material of the biomass extract. Compared with other plants, since perilla has a high nitrogen content, the nitrogen can be prepared by preparing the biomass extract and has a high nitrogen recovery rate. Then, it is introduced into the soil through the organic fertilizer of the present invention, which can increase the nitrogen content in the soil and better promote plant growth.

[0074] The organic fertilizer in the present invention can increase the organic matter and nitrogen content of the soil, adjust the pH value, and the composite bacterial solution can promote the decomposition of organic matter and the effectiveness of nutrients, promote soil improvement, and thus be beneficial to the improvement of soil productivity; at the same time, the organic fertilizer can significantly increase the activity of soil enzymes, promote the improvement of soil fertility, and ultimately achieve the effect of soil conditioning.

[0075] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent measures for the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0076] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

[0077] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a carbon-fixing and nitrogen-retaining biological organic fertilizer, characterized in that: The steps include: (1) crushing corn stalks and polyvinyl alcohol resin by weight, mixing them evenly with a solution containing potassium carbonate and potassium hydroxide, drying them, placing the dried mixture in a carbonization furnace, and carbonizing them under a nitrogen atmosphere to obtain activated biomass charcoal; (2) immersing the activated biochar prepared in step (1) into a mixed solution containing H2O2 and dicobalt ethylenediaminetetraacetate, stirring the mixture for 2-4 hours, and grinding the mixture to obtain a hierarchical pore structure product; (3) mixing the hierarchical pore structure product prepared in step (2) with a composite bacterial solution, and stirring for 1-2 hours to obtain modified biochar, wherein the composite bacterial solution is obtained by mixing azotobacter nitrogen-fixing bacteria, Pantoea anacardiae and Aspergillus niger solution; (4) immersing the modified biochar prepared in step (3) into a mixed solution containing tetraamminecopper sulfate and Mo-EDTA complex, stirring and reacting for 1-2 hours to obtain a supported biochar; (5) The loaded biochar, perilla biomass extract and animal manure are fully mixed, stirred for 20-30 minutes, and concentrated to obtain a carbon-fixing and nitrogen-retaining biological organic fertilizer.

2. The preparation method according to claim 1, characterized in that: In step (1), the mass ratio of corn stalks to polyvinyl alcohol resin is 100:(1-10), and the carbonization temperature is 700-800°C.

3. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of activated biochar to dicobalt ethylenediaminetetraacetate in the mixed solution is 1:(0.01-0.2), and the stirring time is 2 hours.

4. The preparation method according to claim 1, characterized in that: In step (3), the mass ratio of brown spherical nitrogen-fixing bacteria, ananastomella and Aspergillus niger is 2: (1-2): (1-2), and the total mass of the bacteria in the composite bacterial liquid is 2-30% of the mass of the hierarchical pore structure product prepared in step (2).

5. The preparation method according to claim 1, characterized in that: The method for preparing the perilla biomass extract in step (5) comprises: adding perilla to water and stirring for 10 minutes, and heat-treating the obtained juice for 2-3 hours at a heat treatment temperature of 80-120° C. to obtain the perilla biomass extract.

6. The preparation method according to claim 5, characterized in that: The juice is prepared by adding 5-60 grams of perilla to every 1L of water.

7. The preparation method according to claim 1, characterized in that: In step (4), the mass ratio of modified biochar, tetraamminecopper sulfate and Mo-EDTA complex is 1:(0.05-0.2):(0.05-0.2).

8. The preparation method according to claim 1, characterized in that: In step (5), the mass ratio of the supported biochar, the perilla biomass extract and the animal feces is 1:(10-100):(10-100).

9. A carbon-fixing and nitrogen-retaining biological organic fertilizer prepared by the preparation method according to any one of claims 1 to 8.

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