Biochar composite modifier for soil recarburization and carbon stabilization and preparation method thereof

Abstract

The invention relates to the technical field of soil amendments, and discloses a biochar composite amendment for recarburization and carbon stabilization of soil and a preparation method of the biochar composite amendment. 15%-20% of a microbial agent; 25%-35% of an organic fertilizer; and 5%-10% of a water-retaining agent. Comprising the following preparation steps: preparing biochar, culturing a microbial agent, preparing an organic fertilizer and mixing. The soil carbon library stability is improved; the soil fertility is enhanced; the soil structure is improved; the plant growth is promoted;

Description

Technical Field

[0001] The present invention relates to the technical field of soil conditioners, and in particular to a biochar composite conditioner for increasing and stabilizing soil carbon and a preparation method thereof. Background Art

[0002] With the impact of global climate change and human activities, the stability of soil carbon pools has received increasing attention. Organic carbon in soil is an important component of soil fertility and an important part of the global carbon cycle. However, soil is currently facing problems such as carbon loss and decreased fertility, which seriously affects the sustainable development of agriculture and the quality of the ecological environment.

[0003] Traditional soil improvement methods mainly include the application of chemical fertilizers and organic fertilizers, but these methods have some limitations. The long-term and large-scale use of chemical fertilizers can lead to problems such as soil compaction and acidification, reducing soil fertility and biological activity. Although organic fertilizers can increase the content of soil organic matter, they have problems such as slow nutrient release and unstable effects.

[0004] As a new type of soil conditioner, biochar has rich pore structure, large specific surface area and high stability. It can absorb nutrients and water in the soil, improve soil fertility and water retention capacity. At the same time, biochar can also promote the growth and activity of soil microorganisms and enhance the biological activity of the soil. However, there are some problems in the actual application of single biochar conditioner, such as single effect and limited effect.

[0005] Therefore, it is of great practical significance and application value to develop a new type of biochar composite amendment, combining biochar with microbial agents, organic fertilizers, water-retaining agents, etc., to give full play to their respective advantages and improve the soil carbon increase and carbon stabilization effects and comprehensive fertility. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the present invention provides a biochar composite improver for increasing and stabilizing soil carbon and a preparation method thereof.

[0008] (II) Technical solution

[0009] A biochar composite improver for increasing and stabilizing soil carbon, comprising the following components:

[0010] Biochar: 40%-50% of the total mass. The biochar is prepared by high-temperature pyrolysis of agricultural waste and has a rich pore structure and a large specific surface area. The biochar has undergone a special surface activation treatment to give it more active functional groups on the surface, thereby enhancing its ability to adsorb nutrients and water in the soil.

[0011] Microbial agents: accounting for 15%-20% of the total mass, the microbial agents include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria and other beneficial microorganisms, which can promote the transformation and utilization of nutrients in the soil. The microbial agents are processed using a new type of embedding technology, which improves the survival rate and stability of the microorganisms, so that they can play a better role in the soil;

[0012] Organic fertilizer: accounting for 25%-35% of the total mass. The organic fertilizer is decomposed livestock and poultry manure, straw compost, etc., which is rich in organic matter and nutrients. Specific biostimulants are added to the organic fertilizer, which can stimulate the activity of microorganisms in the soil and promote the decomposition and transformation of soil organic matter;

[0013] Water retaining agent: accounting for 5%-10% of the total mass, the water retaining agent is polyacrylamide, which can absorb and retain a large amount of water, improve the water retention capacity of the soil, and has a higher water absorption rate and better salt tolerance.

[0014] Preferably, the method for preparing the biochar is as follows: the agricultural waste is crushed and then subjected to high-temperature pyrolysis under anaerobic conditions, the pyrolysis temperature is 500°C-600°C, the pyrolysis time is 2-3 hours, and the pyrolyzed biochar is ground and sieved to obtain biochar particles with a particle size of 0.1-1 mm.

[0015] Preferably, the ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria in the microbial agent is 3:2:1.

[0016] Preferably, the composting method of the organic fertilizer is: after mixing raw materials such as livestock and poultry manure and straw, adding fermentation bacteria, and performing composting fermentation at a fermentation temperature of 55°C-65°C for 20-30 days. The fermented organic fertilizer is dried and crushed to obtain organic fertilizer particles with a particle size of 1-3 mm.

[0017] Preferably, the method comprises the following preparation steps:

[0018] Prepare biochar: prepare biochar according to the method of claim 2;

[0019] Cultivating microbial agents: Cultivating nitrogen-fixing bacteria, phosphate-dissolving bacteria, potassium-dissolving bacteria, etc. separately, and then mixing them according to the ratio described in claim 3. The mixed microbial agents are processed by a new type of embedding technology to encapsulate the microorganisms in a polymer material to form microcapsules, and the particle size of the microcapsules is 0.1-0.5 mm;

[0020] Preparing organic fertilizer: preparing organic fertilizer according to the method of claim 4;

[0021] Mixing: The prepared biochar, microbial agent microcapsules, organic fertilizer and water retaining agent are mixed according to the proportions described in claim 1, and stirred evenly to obtain a biochar composite improver for soil carbon increase and stabilization.

[0022] Preferably, during the mixing process, a proper amount of adhesive is added to form the biochar composite modifier into granules for easy application. The adhesive can be a natural polymer material or a synthetic polymer material, and the amount added is 1%-3% of the total mass of the biochar composite modifier.

[0023] Preferably, the prepared biochar composite modifier can be packaged and stored. The packaging material can be moisture-proof and breathable materials, such as paper bags, plastic bags, etc. The storage conditions are dry, ventilated, and cool place, avoiding direct sunlight and high temperature.

[0024] (III) Beneficial technical effects

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. Improve soil carbon pool stability

[0027] The biochar in the biochar composite amendment has high stability and can fix organic carbon in the soil for a long time, reduce carbon loss, and improve the stability of the soil carbon pool.

[0028] Microbial agents can promote the decomposition and transformation of organic matter in the soil, increase the soil organic carbon content, and further improve the stability of the soil carbon pool.

[0029] 2. Enhance soil fertility

[0030] Biochar has a rich pore structure and a large specific surface area, which can absorb nutrients and water in the soil and improve soil fertility.

[0031] Microbial agents can fix nitrogen, dissolve phosphorus and potassium, promote the transformation and utilization of nutrients in the soil, and increase the nutrient content of the soil.

[0032] Organic fertilizers are rich in organic matter and nutrients, which can provide sufficient nutrients to the soil and further enhance soil fertility.

[0033] 3. Improve soil structure

[0034] Biochar can increase soil porosity, improve soil aeration and water permeability, and enhance soil water retention capacity.

[0035] Organic fertilizers and microbial agents can promote the formation of soil aggregates, improve soil structure and enhance soil resistance to erosion.

[0036] 4. Promote plant growth

[0037] The microbial agents in the biochar composite amendment can secrete plant growth hormones and promote plant growth and development.

[0038] Water retaining agents can retain soil moisture and provide sufficient water supply for plant growth.

[0039] Biochar, organic fertilizers and microbial agents work together to improve soil fertility and water retention capacity, create a good soil environment for plant growth, and promote plant growth.

[0040] 5. Environmentally friendly

[0041] The biochar in the biochar composite improver is prepared from agricultural waste, which realizes the resource utilization of waste and reduces pollution to the environment.

[0042] Microbial agents and organic fertilizers are natural soil conditioners that are environmentally friendly and meet the requirements of sustainable development. DETAILED DESCRIPTION

[0043] Biochar: accounts for 40%-50% of the total mass of the composite modifier. The biochar is prepared by high-temperature pyrolysis of agricultural waste, has a rich pore structure and a large specific surface area, and has undergone special surface activation treatment.

[0044] Microbial agent: accounting for 15%-20% of the total mass of the composite improver, the microbial agent includes nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and potassium-solubilizing bacteria, and the microbial agent is processed by a new type of embedding technology.

[0045] Organic fertilizer: accounting for 25%-35% of the total mass of the composite improver, the organic fertilizer is decomposed livestock and poultry manure and straw compost, and the biostimulant chitosan oligosaccharide is added to the organic fertilizer.

[0046] Water retaining agent: accounts for 5%-10% of the total mass of the composite improver, and the water retaining agent is polyacrylamide.

[0047] Example 1

[0048] (1) Preparation of biochar: The agricultural waste is crushed and then pyrolyzed under anoxic conditions at a temperature of 600°C for 3 hours. The biochar after pyrolysis is ground and sieved to obtain biochar particles with a particle size of 0.1-1 mm.

[0049] (2) Cultivating microbial agents: nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and potassium-solubilizing bacteria are cultured separately at a mass ratio of 3:2:1, and then mixed. The mixed microbial agents are processed using a new encapsulation technology to encapsulate the microorganisms in sodium alginate to form microcapsules with a particle size of 0.1-0.5 mm.

[0050] (3) Preparation of organic fertilizer: livestock and poultry manure and straw raw materials are mixed, fermentation agents are added, and composting fermentation is carried out at a fermentation temperature of 60°C and a fermentation time of 30 days. The fermented organic fertilizer is dried and crushed to obtain organic fertilizer particles with a particle size of 1-3 mm.

[0051] (4) Mixing: 40 kg of the prepared biochar, 15 kg of microbial agent microcapsules, 35 kg of organic fertilizer, 10 kg of water-retaining agent polyacrylamide, and 1 kg of adhesive sodium carboxymethyl cellulose are mixed and stirred evenly to obtain a biochar composite improver for soil carbon increase and stabilization.

[0052] Comparative Example 1

[0053] (1) Cultivating microbial agents: nitrogen-fixing bacteria, phosphate-dissolving bacteria, and potassium-dissolving bacteria are cultured separately at a mass ratio of 3:2:1, and then mixed. The mixed microbial agents are processed using a new type of encapsulation technology to encapsulate the microorganisms in sodium alginate to form microcapsules. The particle size of the microcapsules is 0.1-0.5 mm.

[0054] (2) Preparation of organic fertilizer: livestock and poultry manure and straw raw materials are mixed, fermentation agents are added, and composting fermentation is carried out at a fermentation temperature of 60°C and a fermentation time of 30 days. The fermented organic fertilizer is dried and crushed to obtain organic fertilizer particles with a particle size of 1-3 mm.

[0055] (3) Mixing: 40 kg of the prepared biochar, 15 kg of microbial agent microcapsules, 35 kg of organic fertilizer, 10 kg of water-retaining agent polyacrylamide, and 1 kg of adhesive sodium carboxymethyl cellulose are mixed and stirred evenly to obtain a biochar composite improver for soil carbon increase and stabilization.

[0056] Comparative Example 2

[0057] (1) Preparation of biochar: The agricultural waste is crushed and then pyrolyzed under anoxic conditions at a temperature of 600°C for 3 hours. The biochar after pyrolysis is ground and sieved to obtain biochar particles with a particle size of 0.1-1 mm.

[0058] (2) Preparation of organic fertilizer: livestock and poultry manure and straw raw materials are mixed, fermentation agents are added, and composting fermentation is carried out at a fermentation temperature of 60°C and a fermentation time of 30 days. The fermented organic fertilizer is dried and crushed to obtain organic fertilizer particles with a particle size of 1-3 mm.

[0059] (3) Mixing: 40 kg of the prepared biochar, 15 kg of microbial agent microcapsules, 35 kg of organic fertilizer, 10 kg of water-retaining agent polyacrylamide, and 1 kg of adhesive sodium carboxymethyl cellulose are mixed and stirred evenly to obtain a biochar composite improver for soil carbon increase and stabilization.

[0060] Fertility test: Example 1 and Comparative Examples 1-2 were used simultaneously, and a blank control was used to perform fertility test according to GB 15618-2018. The results are shown in Table 1;

[0061] Table 1

[0062] Group nitrogen / % phosphorus / % Potassium / % Example 1 12.3 6.5 7.3 Comparative Example 1 11.2 6.3 6.9 Comparative Example 2 10.4 5.8 6.1 blank 0.45 0.12 0.32

[0063] As can be seen from Table 1, the nitrogen, phosphorus and potassium content of Example 1 is the highest, and the addition of biochar and microbial agents can effectively improve soil fertility.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A biochar composite improver for soil carbon increase and stabilization, characterized in that: It is composed of the following ingredients: Biochar: accounting for 40%-50% of the total mass of the composite modifier, the biochar is prepared by high-temperature pyrolysis of agricultural waste, has a rich pore structure and a large specific surface area, and the biochar has undergone special surface activation treatment; Microbial agent: accounting for 15%-20% of the total mass of the composite improver, the microbial agent includes nitrogen-fixing bacteria, phosphate-dissolving bacteria, and potassium-dissolving bacteria, and the microbial agent is processed by a new type of embedding technology; Organic fertilizer: accounting for 25%-35% of the total mass of the composite improver, the organic fertilizer is decomposed livestock and poultry manure, straw compost, and the biostimulant chitosan oligosaccharide is added to the organic fertilizer; Water retaining agent: accounts for 5%-10% of the total mass of the composite improver, and the water retaining agent is polyacrylamide.

2. A biochar composite improver for soil carbon increase and stabilization according to claim 1, characterized in that: The preparation method of the biochar is as follows: agricultural waste is crushed and then subjected to high-temperature pyrolysis under anaerobic conditions, the pyrolysis temperature is 500°C-600°C, the pyrolysis time is 2-3 hours, and the pyrolyzed biochar is ground and sieved to obtain biochar particles with a particle size of 0.1-1 mm.

3. The biochar composite improver for soil carbon increase and stabilization according to claim 1, characterized in that: The ratio of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria in the microbial agent is 3:2:

1.

4. The biochar composite improver for soil carbon increase and stabilization according to claim 1, characterized in that: The method for composting the organic fertilizer is as follows: after mixing livestock and poultry manure and straw, adding fermentation bacteria agent, composting and fermenting, the fermentation temperature is 55-65°C, the fermentation time is 20-30 days, and the fermented organic fertilizer is dried and crushed to obtain organic fertilizer particles with a particle size of 1-3 mm.

5. A biochar composite improver for soil carbon increase and stabilization according to claims 1-4, characterized in that: The method comprises the following preparation steps: Prepare biochar: prepare biochar according to the method of claim 2; Cultivating microbial agents: Cultivating nitrogen-fixing bacteria, phosphate-dissolving bacteria, and potassium-dissolving bacteria respectively, and then mixing them according to the ratio described in claim 3; the mixed microbial agents are processed by a new type of embedding technology to encapsulate the microorganisms in a polymer material to form microcapsules, and the particle size of the microcapsules is 0.1-0.5 mm; Preparing organic fertilizer: preparing organic fertilizer according to the method of claim 4; Mixing: The prepared biochar, microbial agent microcapsules, organic fertilizer and water retaining agent are mixed according to the proportions described in claim 1, and stirred evenly to obtain a biochar composite improver for soil carbon increase and stabilization.

6. A biochar composite improver for soil carbon increase and stabilization according to claim 5, characterized in that: During the mixing process, a binder is added to form the biochar composite modifier into granules for easy application. The binder can be a natural polymer material or a synthetic polymer material, and the amount added is 1%-3% of the total mass of the biochar composite modifier.

7. The biochar composite improver for soil carbon increase and stabilization according to claim 5, characterized in that: The prepared biochar composite modifier can be packaged and stored. The packaging material can be moisture-proof and breathable materials, such as paper bags and plastic bags. The storage conditions are dry, ventilated, and cool place, avoiding direct sunlight and high temperature.