Bio-organic fertilizer for improving salt and alkali as well as preparation method and application of bio-organic fertilizer
By preparing biochar materials and combining them with microbial fermentation, the problems of saline-alkali soil improvement and heavy metal reduction were solved, achieving the effects of improving saline-alkali soil and retaining heavy metals, thereby increasing soil fertility and crop yield.
Patent Information
- Application Number
- CN202511650341.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2025-12-30
AI Technical Summary
Existing technologies are insufficient to effectively improve saline-alkali soils and reduce heavy metal content. Furthermore, bio-EPS adsorbents are easily decomposed and re-released in natural soils, affecting soil improvement results.
Biochar materials are prepared by pyrolysis of agricultural and forestry waste or livestock manure, and combined with fermentation by Bacillus subtilis and actinomycetes to form a porous biochar carrier. This carrier generates bio-EPS in situ, adsorbs cations in saline-alkali soil and retains heavy metal ions, preventing them from decomposing and being released again.
It significantly improves saline-alkali soil, reduces heavy metal content, increases soil fertility, reduces crop absorption of heavy metals, and enhances soil structure and nutrient supply.
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of soil improvers and fertilizers, and particularly relates to a biological organic fertilizer for improving saline-alkali soil, and a preparation method and application thereof. BACKGROUND
[0002] Compared with normal soil, saline-alkali soil has the following characteristics: the content of salt and alkali in saline-alkali soil is higher than that in normal soil, wherein the salt refers to sodium chloride, sodium sulfate and the like, and the alkali refers to sodium carbonate, sodium bicarbonate and the like, all of which exist in the form of sodium salt, and a high content of sodium salt is not conducive to plant growth. When plants absorb too much sodium ion, the cell membrane structure is changed, affecting plant growth. Meanwhile, a high content of sodium ion in plant cells affects photosynthesis. In addition, a high content of sodium ion in soil leads to high soil osmotic pressure, reducing the ability of plants to absorb water, resulting in water deficiency of plants, and ultimately leading to the death of plants. The pH of saline-alkali soil is higher than 7 due to the high content of alkali substances, while the pH of normal soil is close to neutral. The saline-alkali soil is highly compacted, resulting in poor water permeability. Increasing the application of soil conditioners or organic fertilizers is an important measure to improve saline-alkali soil and improve soil fertility. However, the existing methods generally first improve saline-alkali soil by using soil conditioners, and then increase the application of organic fertilizers to improve soil fertility. Therefore, there is a good application prospect for a biological organic fertilizer capable of simultaneously improving saline-alkali soil and improving soil fertility.
[0003] In addition, with the rapid development of modern industry and urbanization, heavy metals (such as Cd, Pb, etc.) generated by human activities are continuously released into the soil environment and stably exist, which not only affects agricultural production, but also threatens human health. However, the existing soil conditioners and biological organic fertilizers have limited solidification effect on heavy metals, and cannot effectively reduce the absorption of heavy metals by planted crops, which has the risk of exceeding the standard of heavy metals.
[0004] EPS (extracellular polymeric substance) adsorption is a process in which natural organic matter complex secreted by microorganisms through metabolic activity can react with heavy metal ions through ion exchange complexation, precipitation and the like, thereby enhancing the adsorption and fixation of metal ions. However, the actual application of biological EPS adsorption to the improvement of saline-alkali soil and heavy metal contaminated soil is less, and the main technical difficulty lies in how to prevent the decomposition and re-release of EPS adsorbents in the natural soil planting environment. SUMMARY
[0005] In view of the shortcomings and deficiencies of the prior art, the primary purpose of the present application is to provide a preparation method of a biological organic fertilizer for improving saline-alkali soil.
[0006] Another purpose of the present application is to provide a biological organic fertilizer prepared by the above method.
[0007] Still another object of the present application is to provide the application of the above-mentioned bio-organic fertilizer in saline-alkali land planting.
[0008] The object of the present application is achieved by the following technical solutions.
[0009] A preparation method of a bio-organic fertilizer for improving saline-alkali soil, comprising the following preparation steps:
[0010] (1) drying the agricultural and forestry waste or livestock manure under anaerobic and 400-700℃ temperature conditions, crushing to obtain biochar material;
[0011] (2) mixing and grinding the biochar material obtained in step (1) with soybean meal and water, then inoculating Bacillus subtilis activation liquid and Actinomycetes activation liquid for fermentation treatment to obtain the bio-organic fertilizer for improving saline-alkali soil.
[0012] Further, in step (1), the agricultural and forestry waste is preferably at least one of straw, chaff, sawdust, bagasse, and fruit shell; and the livestock manure is preferably at least one of cow dung, sheep manure, pig manure, and chicken manure.
[0013] Further, in step (1), the pyrolysis treatment time is preferably 2-6h.
[0014] Further, in step (1), the crushing is preferably crushed to a particle size of 40-80 mesh.
[0015] Further, in step (1), the specific surface area of the biochar material is >400 m² / g.
[0016] Further, in step (2), the mass ratio of the biochar material to soybean meal is 10:2-10; and the water is added to adjust the moisture content to 50-65%.
[0017] Further, in step (2), the inoculation amount of the Bacillus subtilis activation liquid and the Actinomycetes activation liquid is 1~4wt%. The Bacillus subtilis activation liquid and the Actinomycetes activation liquid used in the present application are both commercialized strains activated to a concentration >1×10 8 CFU / mL.
[0018] Further, in step (2), the fermentation treatment temperature is 30-38℃, and the fermentation treatment time is 3-8 days.
[0019] Further, in step (2), the product after fermentation treatment is further dried to a moisture content <30%.
[0020] A bio-organic fertilizer for improving saline-alkali soil, prepared by the above method.
[0021] Application of the above-mentioned biological organic fertilizer for improving saline-alkali soil in saline-alkali land.
[0022] The principle of the present application is that: the biochar material after anaerobic pyrolysis treatment of agricultural and forestry wastes or livestock manure has good porous structure and high specific surface area, and contains rich N, P, K and other nutrient elements; taking the biochar material as a carrier for fermentation and taking soybean meal as the main fermentation nutrient component and organic matter, the natural organic complex secreted by the metabolic activity of Bacillus subtilis and actinomycetes during the fermentation process is generated in situ in the pores and surface of the biochar, and the biochar participates in the adsorption and exchange process of cations in saline-alkali soil through the adsorption of biological EPS, thereby significantly improving the saline-alkali improvement effect and heavy metal ion fixation effect. On the other hand, the porous, high adsorption activity and stable biochar can prevent the decomposition and re-release of the EPS adsorption material in the natural soil planting environment, effectively reducing the content of active heavy metals in the soil and reducing the absorption of heavy metals by planted crops. On the other hand, the continuous release of N, P, K and other nutrient elements and the organic matter after fermentation treatment of the biochar material is beneficial to the absorption of planted crops, thereby significantly improving the fertilizer efficiency.
[0023] Compared with the prior art, the present application has the following advantages:
[0024] (1) The biological organic fertilizer of the present application uses biochar prepared from agricultural and forestry wastes or livestock manure as the main raw material, which has the advantages of wide raw material sources and ecological environmental protection.
[0025] (2) The preparation method of the present application uses porous biochar material as an in-situ carrier for microbial fermentation and EPS production, which can synergistically improve the saline-alkali improvement effect and heavy metal ion fixation effect of the obtained biological organic fertilizer. DETAILED DESCRIPTION
[0026] The present application will be further described in detail below in conjunction with examples, but the embodiments of the present application are not limited thereto.
[0027] Example 1
[0028] A preparation method of a biological organic fertilizer for improving saline-alkali soil, comprising the following preparation steps:
[0029] (1) Dry corn stalks and cow dung are mixed in a mass ratio of 1:1, pyrolysis treated under N2 atmosphere and at a temperature of 560℃ for 4h, crushed through a 60 mesh screen, and a biochar material with a specific surface area of 480 m² / g is obtained.
[0030] (2) The biochar material obtained in step (1) is mixed and ground with soybean meal in a mass ratio of 10:6, water is added to adjust the moisture content to 55-60% during the grinding process, and then 2wt% Bacillus subtilis activation liquid (concentration >1×10 8CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8 Solid-state fermentation was carried out using CFU / mL fertilizer at a controlled temperature of 35-37℃ for 5 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt%, yielding a modified saline-alkali bio-organic fertilizer.
[0031] Example 2
[0032] A method for preparing a bio-organic fertilizer for improving saline-alkali soil includes the following preparation steps:
[0033] (1) Dry rice straw was pyrolyzed for 4 hours under N2 atmosphere and 600℃ temperature, and then crushed through an 80-mesh sieve to obtain biochar material with a specific surface area of 550 m² / g.
[0034] (2) The biochar material obtained in step (1) is mixed with soybean meal at a mass ratio of 10:8 and ground. During the grinding process, water is added to adjust the moisture content to 55-60%. Then, 2wt% Bacillus subtilis activation solution (concentration > 1×10⁻⁶) is inoculated. 8 CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8 Solid-state fermentation was carried out using CFU / mL fertilizer at a controlled temperature of 35-37℃ for 6 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt%, yielding a modified saline-alkali bio-organic fertilizer.
[0035] Example 3
[0036] A method for preparing a bio-organic fertilizer for improving saline-alkali soil includes the following preparation steps:
[0037] (1) Dry rice husks and sheep manure were mixed in a mass ratio of 1:1, and then pyrolyzed at 500℃ for 5 hours under N2 atmosphere. The mixture was then crushed through a 40-mesh sieve to obtain biochar material with a specific surface area of 470 m² / g.
[0038] (2) The biochar material obtained in step (1) is mixed with soybean meal at a mass ratio of 10:4 and ground. During the grinding process, water is added to adjust the moisture content to 55-60%. Then, 2wt% Bacillus subtilis activation solution (concentration > 1×10) is inoculated. 8 CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8Solid-state fermentation was carried out using CFU / mL fertilizer at a controlled temperature of 35-37℃ for 4 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt%, yielding a modified saline-alkali bio-organic fertilizer.
[0039] Example 4
[0040] A method for preparing a bio-organic fertilizer for improving saline-alkali soil includes the following preparation steps:
[0041] (1) Dry pig manure was pyrolyzed for 3 hours under N2 atmosphere and 650℃ temperature, and then crushed through a 60-mesh sieve to obtain biochar material with a specific surface area of 590 m² / g.
[0042] (2) The biochar material obtained in step (1) is mixed with soybean meal at a mass ratio of 10:10 and ground. During the grinding process, water is added to adjust the moisture content to 55-60%. Then, 2wt% Bacillus subtilis activation solution (concentration > 1×10) is inoculated. 8 CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8 Solid-state fermentation was carried out using CFU / mL fertilizer at a controlled temperature of 35-37℃ for 8 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt%, yielding a modified saline-alkali bio-organic fertilizer.
[0043] Example 5
[0044] A method for preparing a bio-organic fertilizer for improving saline-alkali soil includes the following preparation steps:
[0045] (1) Dry bagasse and chicken manure were mixed in a mass ratio of 1:1, and then pyrolyzed at 450°C for 6 hours under N2 atmosphere. The mixture was then crushed through an 80-mesh sieve to obtain biochar material with a specific surface area of 510 m² / g.
[0046] (2) The biochar material obtained in step (1) is mixed with soybean meal at a mass ratio of 10:2 and ground. During the grinding process, water is added to adjust the moisture content to 55-60%. Then, 2wt% Bacillus subtilis activation solution (concentration > 1×10) is inoculated. 8 CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8 Solid-state fermentation was carried out using CFU / mL fertilizer at a controlled temperature of 35-37℃ for 3 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt%, yielding a modified saline-alkali bio-organic fertilizer.
[0047] Comparative Example 1
[0048] This comparative example uses the biochar material obtained in step (1) of Example 1.
[0049] Comparative Example 2
[0050] This comparative example uses the following method to prepare fermented soybean meal bio-organic fertilizer:
[0051] Soybean meal raw material is ground, and water is added during the grinding process to adjust the moisture content to 55-60%. Then, it is inoculated with 2wt% Bacillus subtilis activation solution (concentration > 1×10⁻⁶). 8 CFU / mL) and 1.5 wt% actinomycete activation solution (concentration > 1 × 10⁻⁶ CFU / mL) 8 The soybean meal (CFU / mL) was subjected to solid-state fermentation at a controlled temperature of 35-37℃ for 5 days. Humidity was maintained during fermentation by spraying, and the compost was turned over every 12 hours. After fermentation, the compost was dried to a moisture content of <30wt% to obtain fermented soybean meal bio-organic fertilizer.
[0052] Comparative Example 3
[0053] This comparative example uses a mixture of biochar material from Comparative Example 1 and fermented soybean meal bio-organic fertilizer from Comparative Example 2 at a mass ratio of 10:6.
[0054] The application effects of the products obtained in the above embodiments and comparative examples on planting in saline-alkali land were tested:
[0055] I. The results of salinity and alkalinity and Cd and Pb heavy metal ion content of the saline-alkali land used in the experiment before planting are shown in Table 1 below.
[0056] Table 1
[0057] Item pH Exchangeable sodium content / cmol kg -1 ]] Soil base saturation percentage (ESP) % Available lead (mg / kg) Available cadmium (mg / kg) Results 8.4 16.5 13.6 0.63 0.50
[0058] II. Product Application Method: During the late rice planting season, 7 days before rice transplanting, apply the experimental product at a rate of 300 kg / mu to the field during land preparation and plowing. After plowing, ensure the product is evenly mixed with the soil. Based on the treatments determined in Example 1 and Comparative Examples 1-3, each plot should be coded and labeled. Then, strictly follow the product application method and dosage to apply the corresponding product. Apply 10 catties / mu of urea as topdressing during the tillering stage (15 days after transplanting) and 10 catties / mu of urea as topdressing during the jointing stage. Irrigate according to local field water management practices and weather conditions to ensure consistent water conditions in each plot. Irrigation and drainage should be completed on the same day. Other operations: Do not use plant growth regulators. Follow local conventional management practices and promptly control pests, diseases, and weeds as needed.
[0059] III. Sample Collection and Transfer
[0060] 1. Soil sample collection and transfer
[0061] After the experimental plots were set up, samples were collected during the rice harvest season. Using a 5-point sampling method, soil samples were collected from each plot. At each sampling point, five samples of the top 0-20cm soil (50cm in diameter) were drilled and mixed, with approximately 1kg of fresh soil mixed in each sample. The samples were then sealed in clean plastic bags, and the labels were numbered to match the field tags. The samples were then transferred to a qualified third-party testing agency for analysis.
[0062] 2. Rice Sample Collection and Transfer
[0063] Rice samples and soil samples should be collected simultaneously, avoiding sampling times during or after strong winds and rain. Using a 5-point sampling method, agricultural product samples should be collected from each plot, with 5 random sampling points within the plot. Collect 2-3 rice clumps at each point. After thoroughly drying and mixing the rice from the 5 points to remove impurities, pack them separately into mesh bags, ensuring each replicate weighs approximately 500g of dry rice. If the quantity is insufficient, increase the number of sampling clumps. Samples (at least 20g) should be individually packaged in plastic bags for testing and properly labeled. The prepared rice samples should be transferred to a qualified third-party testing institution for analysis.
[0064] IV. Test Results
[0065] 1. The soil sample test results are shown in Table 2 below:
[0066] Table 2
[0067] Item pH Exchangeable sodium content / cmol kg -1 ]] Soil base saturation percentage (ESP) % Available lead (mg / kg) Available cadmium (mg / kg) Example 1 7.4 5.8 5.2 0.32 0.31 Comparative Example 1 8.2 9.6 8.7 0.48 0.40 Comparative Example 2 7.9 12.3 9.5 0.55 0.46 Comparative Example 3 7.8 9.8 8.4 0.47 0.42
[0068] As shown in Table 2, the effects of using biochar alone or fermented soybean meal bio-organic fertilizer alone on improving salinity and reducing the content of available heavy metals were significantly lower than those of the bio-organic fertilizer of this invention. Comparative Example 3 shows that the mixture of biochar and fermented soybean meal bio-organic fertilizer did not show a significant improvement in effect compared to either biochar alone or fermented soybean meal bio-organic fertilizer alone. This demonstrates that the in-situ loaded bio-EPS adsorption and biochar of this invention have a significant synergistic effect on improving soil salinity and reducing the content of available heavy metals.
[0069] 2. The test results of the rice samples are shown in Table 3 below:
[0070] Table 3
[0071] Item Lead content (mg / kg) Cadmium content (mg / kg) Yield (kg / ha) Example 1 0.15 0.18 7024 Comparative Example 1 0.28 0.35 5660 Comparative Example 2 0.30 0.43 6075 Comparative Example 3 0.27 0.40 6482
[0072] The results in Table 3 further demonstrate that the in-situ loaded biological EPS adsorption and biochar of this invention have a significant synergistic effect on reducing crop absorption of heavy metals and improving fertilizer efficiency.
[0073] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A method for preparing a biological organic fertilizer for improving saline-alkali soil, characterized in that: The method comprises the following steps: (1) drying the agricultural and forestry waste or livestock manure under anaerobic and 400-700℃ temperature conditions, crushing to obtain biochar material; (2) mixing the biochar material obtained in step (1) with soybean meal and water, grinding, then inoculating Bacillus subtilis and actinomycete activation liquid for fermentation treatment to obtain improved saline-alkali bio-organic fertilizer.
2. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The agricultural and forestry waste in step (1) is at least one of straw, chaff, sawdust, bagasse and fruit shell; the livestock manure is at least one of cow dung, sheep manure, pig manure and chicken manure.
3. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The pyrolysis treatment time in step (1) is 2-6h; the particle size of the crushing is 40-80 mesh.
4. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The specific surface area of the biochar material in step (1) is >400 m² / g.
5. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The mass ratio of the biochar material to soybean meal in step (2) is 10:2-10; the water is added to adjust the moisture content to 50-65%.
6. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The inoculation amount of the Bacillus subtilis activation solution and the actinomycete activation solution in step (2) is 1-4 wt%; the concentration of the Bacillus subtilis activation solution and the actinomycete activation solution is >1×10 8 CFU / mL.
7. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The fermentation temperature in step (2) is 30-38℃, and the fermentation time is 3-8 days.
8. The method for preparing the biological organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that: The product after the fermentation treatment in step (2) is further dried to a moisture content <30%.
9. A bio-organic fertilizer for improving saline-alkali soil, characterized in that: The improved saline-alkali bio-organic fertilizer is prepared by the method of any one of claims 1-8.
10. The use of the improved saline-alkali bio-organic fertilizer of claim 9 in saline-alkali land planting.