A fertilizer for wetland category alkali soil and a method for preparing the same

Abstract

The application discloses a fertilizer for wetland category alkaline soil and a preparation method thereof, and relates to the technical field of fertilizer preparation. In one aspect, the application discloses a fertilizer for wetland category alkaline soil, which comprises the following raw materials in parts by weight: 60-90 parts of mature compost, 5-10 parts of ferrous sulfate, 10-18 parts of sulfur-containing gypsum, 12-20 parts of polyaspartamide, 6-10 parts of biomass charcoal and 1-5 parts of microbial inoculum. In another aspect, the application further provides a preparation method of the fertilizer for wetland category alkaline soil. The fertilizer for wetland category alkaline soil provided by the application can be applied to wetland category alkaline soil, and can effectively improve the high salinity of the wetland category alkaline soil.

Description

Technical Field

[0001] This application relates to the field of fertilizer preparation technology, and in particular to a fertilizer for alkaline soils in wetland areas and a method for preparing the same. Background Technology

[0002] Alkaline soil refers to soil with a high pH value, meaning it is alkaline or slightly alkaline. Alkaline soil has a certain impact on plant growth; some plants are particularly sensitive to alkaline soil and have a lower survival rate in such environments. Furthermore, the high salt concentration and alkaline environment of alkaline soil can limit root growth and water absorption, affecting plant growth and development. Therefore, developing fertilizers suitable for alkaline soils is particularly important.

[0003] In reality, the formation of alkaline soils is controlled by various factors and is significantly influenced by regional differences. Soil salinization and alkalization often occur simultaneously. Currently, due to the continuously increasing intensity of human interference, grassland vegetation has been severely damaged. Many of these areas are coastal and fall under the category of wetlands, where the salinity of seawater significantly affects the salt and alkali content of the soil, leading to severe soil salinization and causing serious harm. However, most existing fertilizers are suitable for inland farmland soils, with fewer fertilizers suitable for alkaline soils in coastal wetlands, and their effectiveness is not very good.

[0004] Therefore, there is an urgent need for a fertilizer that can be applied to wetland soils with high salinity and alkalinity to solve the problems existing in the current technology. Summary of the Invention

[0005] In order to solve at least one of the above-mentioned technical problems and to develop a fertilizer applicable to wetland soils with high salinity and alkalinity, this application provides a fertilizer for alkaline soils in wetland areas and a method for preparing the same.

[0006] On the one hand, the fertilizer provided in this application for alkaline soils in wetlands comprises, by weight, the following raw materials: 60-90 parts of well-rotted compost, 5-10 parts of ferrous sulfate, 10-18 parts of sulfur-containing gypsum, 12-20 parts of polyasparagine, 6-10 parts of biochar, and 1-5 parts of microbial inoculant.

[0007] By adopting the above technical solution, the fertilizer provided in this application, in the process of composting, introduces ferrous sulfate and sulfur-containing gypsum. While providing essential organic matter and other nutrients for plant growth, improving soil structure and maintaining soil moisture, ferrous sulfate and sulfur-containing gypsum can also provide abundant sulfur elements, thereby providing essential sulfur nutrition for plant growth, improving the plant's nutrient absorption capacity, and promoting normal plant growth.

[0008] Meanwhile, ferrous sulfate and sulfur-containing gypsum can also lower the soil pH and promote the activity of soil microorganisms. Specifically, ferrous sulfate can react with soil salts to form insoluble precipitates, thus fixing the salts; sulfur-containing gypsum can promote the formation of soil aggregates, increase soil permeability and aeration, which is beneficial for water infiltration and retention. Furthermore, the calcium ions released from the decomposition of sulfur-containing gypsum can undergo ion exchange with metal ions in the salt, and the released sulfate ions can react chemically with metal ions, thereby reducing soil salinity and alleviating the soil's salinity and alkalinity load.

[0009] On the other hand, the fertilizer provided in this application specifically targets alkaline soils in wetlands by introducing polyasparagine, which can further improve the salinity of alkaline soils in wetlands. Polyasparagine has excellent precipitation properties and water absorption and retention capacity, which can increase the soil's water retention capacity. Moreover, the polyasparagine molecule contains abundant carboxyl groups, which can chelate with metal ions to form stable chelates and then precipitate. At the same time, polyasparagine also has extremely high polarity and ionicity, which can form a large number of hydrates with water molecules in high-salt environments. This leads to the expansion and aggregation of polyasparagine molecules, forming a gel-like substance to encapsulate and fix salts, forming precipitates, thereby reducing the salt content in the soil.

[0010] This application also introduces biochar and microbial agents in addition to polyasparagine. Biochar is an organic residue with high porosity and adsorption capacity, while microbial agents are preparations containing beneficial microorganisms. When biochar and microbial agents are used together with polyasparagine in fertilizers, polyasparagine can help stabilize soil particles and prevent the loss of biochar particles and microbial agents. Biochar can increase the porosity and adsorption capacity of the soil, while microbial agents can promote the growth and activity of beneficial microorganisms, increase the decomposition and transformation of soil organic matter, thereby improving the dispersibility and water retention capacity of polyasparagine.

[0011] Optional, by weight, the following raw materials are included: 70-80 parts of well-rotted compost, 7-9 parts of ferrous sulfate, 14-16 parts of sulfur-containing gypsum, 16-18 parts of polyasparagine, 7-8 parts of biochar, and 2-4 parts of microbial inoculant.

[0012] By adopting the above technical solution, the weight proportions of raw materials are further limited, which can further improve the fertilizer's ability to improve the high salinity and alkalinity of alkaline soils in wetland areas.

[0013] Optionally, the microbial agent includes rhizobia and actinomycetes, and the mass ratio between the rhizobia and the actinomycetes is 1 to 3:1.

[0014] By adopting the above technical solution, the composition of microbial agents has been further defined. The enzymes secreted by rhizobia and actinomycetes can degrade organic matter and release organic acids and other compounds, thereby promoting soil acidification and reducing soil alkalinity. In addition, the growth of actinomycetes can produce extracellular polysaccharides and extracellular enzymes, which help to form soil aggregate structures and increase soil permeability. Rhizobia and plant roots can form root nodules. At the same time, the addition of rhizobia and actinomycetes can improve soil structure and water retention capacity. Furthermore, actinomycetes can assist rhizobia in nitrogen fixation, providing nitrogen for plant growth and development.

[0015] Optionally, the mass ratio of the polyasparagine to the biochar is 2:1.

[0016] By adopting the above technical solutions, the improvement effect on alkaline soils in wetland areas can be further enhanced.

[0017] Optionally, the mass ratio between the polyasparagine and the microbial agent is 4:1.

[0018] By adopting the above technical solutions, the improvement effect on alkaline soils in wetland areas can be further enhanced.

[0019] Optionally, the degree of polymerization of the polyasparagine is 1×10⁻⁶. 6 ~1×10 7 .

[0020] By adopting the above technical solution, when the degree of polymerization of polyasparagine is low, the molecular chain is short and the interaction with soil particles and salt ions is small. However, when the degree of polymerization is too high, it is easy to cause anti-saltation and anti-acidification. Therefore, this application further limits the degree of polymerization of polyasparagine, which enables polyasparagine to interact better with soil particles and salt ions, helps to reduce the migration of soil particles and improve the soil's salt and alkali resistance.

[0021] Optionally, the polyasparagine includes at least one of adhesive polyasparagine and branched polyasparagine.

[0022] By adopting the above technical solutions, in alkaline soils within wetlands where water erosion is common, adhesive polyasparagine and branched polyasparagine can form a stable colloidal structure in the soil, increasing the cohesion between soil particles and reducing their mobility. Simultaneously, they can adsorb salts and alkaline substances in the soil, forming stable complexes on the surface of soil particles, thus reducing the dissolution and migration of salts and alkaline substances.

[0023] Further optionally, the polyasparagine is adhesive polyasparagine and branched polyasparagine, and the mass ratio between the adhesive polyasparagine and the branched polyasparagine is 3:1.

[0024] By adopting the above technical solutions, the improvement effect on alkaline soils in wetland areas can be further enhanced.

[0025] Optionally, the biochar has a particle size of 0.5 to 2 mm.

[0026] By adopting the above technical solutions, biochar with smaller particle size has more micropores and a higher specific surface area, which can more effectively adsorb and fix salts in the soil. However, excessively small particle size may lead to dense particle packing, affecting the permeability of water and gas. Therefore, the particle size of biochar has been further limited.

[0027] Secondly, this application provides a method for preparing the above-mentioned fertilizer for alkaline soils in wetlands, comprising the following steps: mixing well-rotted compost, ferrous sulfate, sulfur-containing gypsum, polyasparagine, biochar and microbial agents according to parts by weight to obtain the fertilizer for alkaline soils in wetlands.

[0028] By adopting the above technical solution, the fertilizer for alkaline soils in wetlands provided in this application can be prepared relatively easily, and the operation is simple and convenient.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. This application introduces ferrous sulfate and sulfur-containing gypsum into well-rotted compost. While providing essential nutrients for plant growth, improving soil structure, and maintaining soil moisture, both ferrous sulfate and sulfur-containing gypsum can provide abundant sulfur nutrition for plant growth. At the same time, ferrous sulfate and sulfur-containing gypsum can also reduce soil pH, promote the activity of soil microorganisms, and reduce soil salinity, thereby alleviating the soil salinity and alkalinity load.

[0031] 2. This application specifically targets alkaline soils in wetland areas by introducing polyasparagine. Polyasparagine can increase the soil's water retention capacity and can chelate with metal ions to form stable chelates that then precipitate. At the same time, polyasparagine can form a large number of hydrates with water molecules to form a gel-like substance that can be used to encapsulate and fix salts, forming precipitates, thereby further improving the salinity of alkaline soils in wetland areas.

[0032] 3. In addition to polyasparagine, this application also introduces biochar and microbial agents. Polyasparagine can help stabilize soil particles and prevent the loss of biochar particles and microbial agents, while biochar can increase soil porosity and adsorption capacity, and microbial agents can promote the growth and activity of beneficial microorganisms, increase the decomposition and transformation of soil organic matter, thereby improving the dispersibility and water retention capacity of polyasparagine.

[0033] 4. The method for preparing fertilizer for alkaline soils in wetlands provided in this application is simple and convenient to operate, and can relatively easily prepare the fertilizer for alkaline soils in wetlands provided in this application. Detailed Implementation

[0034] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0035] This application designs a fertilizer for alkaline soils in wetlands, comprising the following raw materials by weight: 60-90 parts of well-rotted compost, 5-10 parts of ferrous sulfate, 10-18 parts of sulfur-containing gypsum, 12-20 parts of polyasparagine, 6-10 parts of biochar, and 1-5 parts of microbial inoculant.

[0036] The fertilizer for alkaline soils in wetlands described in this application is prepared by the following method, including the following steps: mixing well-rotted compost, ferrous sulfate, sulfur-containing gypsum, polyasparagine, biochar, and microbial inoculants in parts by weight to obtain the fertilizer for alkaline soils in wetlands. Specific Implementation

[0038] Unless otherwise specified, all raw materials used in the embodiments and comparative examples of this application are commercially available products:

[0039] Well-rotted compost: moisture content ≤ 5%;

[0040] Ferrous sulfate: 99% purity;

[0041] Sulfur-containing gypsum: 97% purity;

[0042] Polyasparagine: Linear polyasparagine, degree of polymerization 1×10 5 ~1×10 8 Branched polyasparagine, degree of polymerization 1×10 5 ~1×10 8 Adhesive-type polyasparagine, degree of polymerization 1×10 5 ~1×10 8 ;

[0043] Biochar: Rice husk char, with a particle size of 0.1–3 mm;

[0044] Microbial inoculants: Rhizobium, Rhizobium raw powder, 99% purity; Actinomycetes, Actinomycete raw powder, 99% purity.

[0045] Examples 1-23 and Comparative Examples 1-3 of this application provide fertilizers for alkaline soils in wetlands. When testing these fertilizers, the fertilizers were mixed thoroughly and applied to the alkaline soils at a dosage of 30 kg per acre. Soil samples were collected from different locations, mixed, and then air-dried at room temperature. The dried soil samples were then mixed with distilled water at a mass ratio of 1:5 to prepare a soil solution. Additionally, a blank control soil solution was prepared from soil samples of alkaline soils in wetlands without any added fertilizer. These solutions were used to test the fertilizers provided in Examples 1-23 and Comparative Examples 1-3 for alkaline soils in wetlands. Specifically, the testing items are as follows:

[0046] 1. pH value: measures the concentration of hydrogen ions in the soil solution;

[0047] 2. Salt content: Measured by the electrical conductivity of the soil solution.

[0048] Example 1

[0049] This embodiment provides a fertilizer for alkaline soils in wetlands, comprising the following raw materials by weight: 60 kg of well-rotted compost, 5 kg of ferrous sulfate, 10 kg of sulfur-containing gypsum, 20 kg of polyasparagine, 6 kg of biochar, and 1 kg of microbial inoculant; wherein the microbial inoculant comprises rhizobia and actinomycetes in a mass ratio of 1:2, and the polyasparagine has a degree of polymerization of 1×10⁻⁶. 5 ~1×10 6 The linear polyasparagine and the biochar are rice husk char with a particle size of 0.1-0.5 mm.

[0050] The above-mentioned fertilizer for alkaline soils in wetlands is prepared by mixing well-rotted compost, ferrous sulfate, sulfur-containing gypsum, polyasparagine, biochar, and microbial agents according to the weight proportions to obtain the fertilizer for alkaline soils in wetlands.

[0051] Examples 2-5 and Comparative Examples 1-3

[0052] Based on Example 1, Examples 2-5 and Comparative Examples 1-3 differ from Example 1 in that the raw material composition is different (see Table 1); the remaining steps, conditions and parameters are the same as in Example 1.

[0053] Table 1. Raw material composition of Examples 2-5 and Comparative Examples 1-3

[0054] Unit: kg Well-rotted compost Ferrous sulfate Sulfur-containing gypsum Polyasparagine Biochar Microbial agents Example 2 90 10 18 12 10 5 Example 3 70 7 14 16 7 2 Example 4 80 9 16 18 8 4 Example 5 75 8 15 17 7.5 3 Comparative Example 1 60 5 10 / 6 1 Comparative Example 2 60 5 10 20 / 1 Comparative Example 3 60 5 10 20 6 /

[0055] The fertilizers provided in Examples 1-5 and Comparative Examples 1-3 for use in alkaline soils within the wetland category were tested experimentally, and the test results are shown in Table 2.

[0056] Table 2 Summary of test results for Examples 1-5 and Comparative Examples 1-3

[0057]

[0058]

[0059] Referring to Table 2, the test results show that the pH values ​​of Examples 1-5 were all between 7.30 and 7.45, and the electrical conductivity was all between 1.55 and 1.85 mS / m. Compared with the blank control, these examples significantly improved the salinity of alkaline soils in wetlands. Although Comparative Examples 1-3 also improved the salinity of alkaline soils in wetlands, the improvement effect was not as good as that of Examples 1-5. This demonstrates the superiority of this application in simultaneously using polyasparagine, 6-10 parts of biochar, and microbial agents. Based on the combined test results of Examples 1-5, Example 5 showed the lowest pH value and electrical conductivity.

[0060] Examples 6-9

[0061] Based on Example 5, the difference between Examples 6 to 9 and Example 5 is that the mass ratio of rhizobium and actinomycetes in the microbial inoculant is different, namely 1:1, 2:1, 3:1 and 4:1 respectively; the remaining steps, conditions and parameters are the same as in Example 5.

[0062] The fertilizers provided in Examples 6-9 for use in alkaline soils within the wetland category were tested experimentally, and the test results are shown in Table 3.

[0063] Table 3 Summary of test results for Examples 6-9

[0064] pH value Electrical conductivity (mS / m) Example 6 7.26 1.53 Example 7 7.25 1.51 Example 8 7.27 1.57 Example 9 7.33 1.62

[0065] Referring to Table 3, the test results show that the pH values ​​of Examples 6-9 are all between 7.25 and 7.35, and the conductivity is all between 1.50 and 1.65 mS / m. Specifically, the pH values ​​and conductivity of Examples 6-8 are lower than those of Examples 5 and 9, demonstrating the superiority of the microbial inoculant composed of rhizobia and actinomycetes in a specific mass ratio. Considering the test results of Examples 6-8, the pH value and conductivity of Example 7 are even lower.

[0066] Example 10

[0067] Based on Example 7, the difference between this example and Example 7 is that the weight proportions of polyasparagine and biochar in the raw material composition are different. In this example, 16 kg of polyasparagine and 8 kg of biochar were added; the remaining steps, conditions and parameters are the same as in Example 7.

[0068] Example 11

[0069] Based on Example 10, the difference between this example and Example 10 is that the weight of the microbial agent in the raw material composition is different. In this example, 4 kg of microbial agent was added; the rest of the steps, conditions and parameters are the same as in Example 10.

[0070] The fertilizers provided in Examples 10-11 for alkaline soils in wetland areas were tested, and the results are shown in Table 4.

[0071] Table 4 Summary of test results for Examples 10-11

[0072] pH value Electrical conductivity (mS / m) Example 10 7.23 1.49 Example 11 7.22 1.46

[0073] Referring to Table 4, the test results show that the pH values ​​of Examples 10 and 11 are all between 7.20 and 7.25, and the conductivity is all between 1.45 and 1.50 mS / m. Specifically, the pH value and conductivity of Example 10 are lower than those of Example 7, and the pH value and conductivity of Example 11 are lower than those of Example 10. This demonstrates the superiority of using specific mass ratios of polyasparagine and biochar, as well as specific mass ratios of polyasparagine and microbial agents.

[0074] Examples 12-14

[0075] Based on Example 11, Examples 12-14 differ from Example 11 in that the degree of polymerization of polyasparagine is different, being 1×10⁻⁶ respectively. 6 ~5×10 6 5×10 6 ~1×10 7 and 1×10 7 ~1×10 8 The remaining steps, conditions, and parameters are the same as in Example 11.

[0076] The fertilizers provided in Examples 12-14 for alkaline soils in wetland areas were tested, and the results are shown in Table 5.

[0077] Table 5 Summary of test results for Examples 12-14

[0078] pH value Electrical conductivity (mS / m) Example 12 7.20 1.43 Example 13 7.18 1.40 Example 14 7.24 1.52

[0079] Referring to Table 5, the test results show that the pH values ​​of Examples 12-14 are all between 7.15 and 7.25, and the conductivity is all between 1.40 and 1.55 mS / m. Specifically, the pH values ​​and conductivity of Examples 12-13 are lower than those of Examples 11 and 14, demonstrating the superiority of using polyasparagine with a specific degree of polymerization. Combining the test results of Examples 12-13, it is clear that Example 13 has even lower pH values ​​and conductivity.

[0080] Examples 15-19

[0081] Based on Example 13, Examples 15-19 differ from Example 13 in that the structure of polyasparagine is different (see Table 6); the remaining steps, conditions and parameters are the same as in Example 13.

[0082] Table 6. Types of polyasparagine used in Examples 15-19

[0083] Unit: kg Linear polyasparagine Adhesive polyasparagine Branched polyasparagine Example 15 / 16 / Example 16 / / 16 Example 17 / 4 12 Example 18 / 8 8 Example 19 / 12 4

[0084] The fertilizers provided in Examples 15-19 for alkaline soils in wetland areas were tested, and the results are shown in Table 7.

[0085] Table 7 Summary of test results for Examples 15-19

[0086] pH value Electrical conductivity (mS / m) Example 15 7.16 1.36 Example 16 7.17 1.38 Example 17 7.15 1.35 Example 18 7.14 1.34 Example 19 7.12 1.31

[0087] Referring to Table 7, the test results show that the pH values ​​of Examples 15-19 are all between 7.10 and 7.20, and the conductivity is all between 1.30 and 1.40 mS / m. Specifically, the pH values ​​and conductivity of Examples 17-19 are lower than those of Examples 13 and Examples 15-16, and among Examples 17-19, the pH value and conductivity of Example 19 are even lower. This demonstrates the superiority of polyasparagine using a specific structure and a specific mass ratio.

[0088] Examples 20-23

[0089] Based on Example 19, the difference between Examples 20 to 23 and Example 19 is that the particle size of the biochar is different, namely 0.5-1 mm, 1-1.5 mm, 1.5-2 mm and 2-3 mm respectively; the remaining steps, conditions and parameters are the same as in Example 19.

[0090] The fertilizers provided in Examples 20-23 for alkaline soils in wetland areas were tested, and the results are shown in Table 8.

[0091] Table 8 Summary of test results for Examples 20-23

[0092]

[0093]

[0094] Referring to Table 8, the test results show that the pH values ​​of Examples 20-23 are all between 7.05 and 7.15, and the conductivity is all between 1.25 and 1.40 mS / m. Specifically, the pH values ​​and conductivity of Examples 20-22 are lower than those of Examples 19 and 23, demonstrating the superiority of using biochar with a specific particle size. Considering the test results of Examples 20-22, the pH value and conductivity of Example 21 are even lower.

[0095] In summary, the fertilizer provided in this application for alkaline soils in wetlands has significant advantages in improving the high salinity of alkaline soils in wetlands.

[0096] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A fertilizer for alkaline soils in wetlands, characterized in that, By weight, it includes the following raw materials: 60-90 parts of well-rotted compost, 5-10 parts of ferrous sulfate, 10-18 parts of sulfur-containing gypsum, 12-20 parts of polyasparagine, 6-10 parts of biochar, and 1-5 parts of microbial inoculant. The polyasparagine is an adhesive polyasparagine and a branched polyasparagine, and the mass ratio between the adhesive polyasparagine and the branched polyasparagine is 3:

1. The mass ratio of the polyasparagine to the biochar is 2:1; The degree of polymerization of the polyasparagine is 1×10⁻⁶. 6 -1×10 7 .

2. The fertilizer for alkaline soils in wetlands according to claim 1, characterized in that, By weight, it includes the following raw materials: 70-80 parts of well-rotted compost, 7-9 parts of ferrous sulfate, 14-16 parts of sulfur-containing gypsum, 16-18 parts of polyasparagine, 7-8 parts of biochar, and 2-4 parts of microbial inoculant.

3. The fertilizer for alkaline soils in wetlands according to claim 1, characterized in that, The microbial agent includes rhizobia and actinomycetes, and the mass ratio of the rhizobia to the actinomycetes is 1 to 3:

1.

4. The fertilizer for alkaline soils in wetlands according to claim 1, characterized in that, The mass ratio of the polyasparagine to the microbial inoculant is 4:

1.

5. The fertilizer for alkaline soils in wetlands according to claim 1, characterized in that, The biochar has a particle size of 0.5~2 mm.

6. A method for preparing a fertilizer for alkaline soils in wetlands as described in claim 1, characterized in that, The process includes the following steps: mixing well-rotted compost, ferrous sulfate, sulfur-containing gypsum, polyasparagine, biochar, and microbial agents according to the specified weight proportions to prepare the fertilizer for alkaline soils in wetlands.

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