A bio-enzyme composite organic fertilizer for saline-alkali soil improvement and a preparation method thereof

Abstract

The application belongs to the technical field of organic fertilizer, and particularly relates to a biological enzyme composite organic fertilizer for saline-alkali soil improvement and a preparation method thereof. The biological enzyme composite organic fertilizer comprises the following raw materials in parts by weight: livestock and poultry manure 40-50 parts, composite microbial agent 10-12 parts, ferrous sulfate 10-15 parts, lignite 8-15 parts, urea 8-12 parts, biological enzyme 5-8 parts, superphosphate 5-9 parts, N-carbamoyl glutamic acid 1-3 parts and zeolite powder 1-5 parts. The biological enzyme composite organic fertilizer can effectively reduce the soil pH value and total salt content, enhance the soil water and fertilizer retention capacity, improve the crop yield, is safe and pollution-free, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of organic fertilizer technology, specifically relating to a bio-enzyme compound organic fertilizer for improving saline-alkali soil and its preparation method. Background Technology

[0002] Saline-alkali land refers to degraded land containing excessive soluble salts or exchangeable sodium ions, leading to increased soil pH and deteriorated physical structure. This severely restricts agricultural development and ecological environment improvement. High pH and high salinity directly inhibit crop seed germination, root growth, and nutrient absorption, resulting in stunted crops, reduced yields, or even crop failure. Soil compaction and poor permeability further exacerbate water and fertilizer loss and surface runoff, creating a vicious cycle of drought, flooding, salinity, and alkaliness. Saline-alkali land management can not only improve land productivity and farmers' income, promoting regional economic development, but also increase arable land area to meet the growing demand for food.

[0003] However, traditional treatment methods have many limitations: flood irrigation for salt leaching may be effective in the short term, but it consumes a lot of water and can easily cause groundwater rise and secondary salinization; chemical amendments are costly and long-term use may cause secondary pollution; simply applying organic fertilizers or microbial agents often results in low microbial survival rates and unstable effects due to salt and alkali stress. Therefore, developing a novel bio-enzyme compound organic fertilizer that integrates salt reduction, alkali reduction, fertilization, and growth promotion has significant practical importance and broad application prospects. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the first objective of this invention is to provide a bio-enzyme compound organic fertilizer for improving saline-alkali soil. This organic fertilizer can effectively reduce soil pH and total salt content, enhance soil water and fertilizer retention capacity, increase crop yield, and is safe and pollution-free.

[0005] The second objective of this invention is to provide a method for preparing a bio-enzyme compound organic fertilizer for improving saline-alkali soil, which is easy to operate.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A bio-enzyme compound organic fertilizer for improving saline-alkali soil comprises the following raw materials in parts by weight: 40-50 parts of livestock and poultry manure, 10-12 parts of compound microbial agent, 10-15 parts of ferrous sulfate, 8-15 parts of lignite, 8-12 parts of urea, 5-8 parts of bio-enzyme, 5-9 parts of superphosphate, 1-3 parts of N-carbamoylglutamic acid, and 1-5 parts of zeolite powder; wherein the compound microbial agent includes Bacillus mucilaginosus and Bacillus oryzae.

[0007] Furthermore, the effective viable bacteria count in the compound microbial agent is (1-5) × 10⁻⁶. 9CFU / g; the ratio of effective viable bacteria of Bacillus mucilaginosus and Bacillus oryzae is 1:(1-1.5).

[0008] Furthermore, the bio-enzyme is composed of urease, phosphatase and cellulase in a mass ratio of 1:(6-8):(10-12).

[0009] The preparation method of the above-mentioned bio-enzyme compound organic fertilizer for saline-alkali soil improvement includes the following steps: (1) Mix the fermentation broth of Bacillus mucilaginosus with the fermentation broth of Bacillus simulans to obtain a compound microbial agent; (2) The lignite was soaked in nitric acid solution, and then washed, dried and sterilized to obtain a pretreated coal sample; (3) After adjusting the moisture content of the livestock and poultry manure, it is then mixed with the pretreated coal sample, ferrous sulfate, urea, N-carbamoylglutamic acid, superphosphate and zeolite powder to obtain a mixture; (4) Add the compound microbial agent and biological enzyme to the mixture, ferment, dry, granulate, coat and dry.

[0010] Furthermore, the preparation process of Bacillus mucilaginosus fermentation broth and Bacillus simonii fermentation broth in step (1) is as follows: Bacillus mucilaginosus and Bacillus simonii are activated with NA medium and then inoculated into fermentation medium to obtain fermentation broth.

[0011] Furthermore, the fermentation medium is composed of: peptone 8-11 g / L, beef extract 2-4 g / L, sodium acetate 3-5.6 g / L, magnesium sulfate 0.3-0.6 g / L, zinc sulfate 0.1-0.23 g / L, ferric sulfate 0.1-0.3 g / L, manganese sulfate 0.2-0.25 g / L, and potassium dihydrogen phosphate 3-4.2 g / L.

[0012] Furthermore, the concentration of the nitric acid solution in step (2) is 8-10 mol / L; the soaking time is 48-50 h; and the particle size of the lignite is 0.125-0.250 mm.

[0013] Furthermore, in step (3), the moisture content of the livestock and poultry manure is adjusted to 60-65%.

[0014] Furthermore, the fermentation temperature in step (4) is 30-33℃ and the time is 10-12 days.

[0015] Furthermore, in step (4), the coating solution is prepared by dissolving trehalose and xanthan gum in water at a mass ratio of 1:3 to obtain a solution with a mass fraction of 0.5-2%.

[0016] Compared with the prior art, the main advantages of the present invention are as follows: (1) This invention provides a bio-enzyme compound organic fertilizer for improving saline-alkali soil, the raw materials of which include livestock and poultry manure, compound microbial agents, ferrous sulfate, lignite, urea, bio-enzymes, superphosphate, N-carbamoylglutamic acid and zeolite powder. This organic fertilizer can effectively reduce soil pH and total salt content, enhance soil water and fertilizer retention capacity, increase crop yield, and is safe and pollution-free, with broad application prospects.

[0017] (2) This invention combines Bacillus spp. and Bacillus mucilaginosus to form a compound microbial agent, which effectively reduces soil pH and total salt content, and promotes crop growth. Specifically, Bacillus spp. has excellent tolerance to high salt and high nitrogen. It not only metabolizes and secretes a large amount of low-molecular organic acids and amino acids, but also effectively degrades lignite to release humic acid, neutralizes and degrades hydroxide ions accumulated around the rhizosphere, and dissolves and destroys carbonate and bicarbonate crystals in the soil, thereby reducing the rhizosphere pH value from the source, achieving targeted alkali reduction in saline-alkali soil, and improving the soil micro-ecological environment.

[0018] (3) This invention also introduces N-carbamoylglutamic acid to reduce soil pH and total salt content, thereby promoting crop growth. As a small molecule osmotic regulator and enzyme protectant, N-carbamoylglutamic acid can reduce the intracellular osmotic pressure of microbial cells, maintain intracellular ion balance, protect cell membrane integrity, and improve the survival rate and reproductive capacity of microorganisms in saline-alkali soil, thereby promoting continuous acid production by microorganisms to reduce soil pH. At the same time, N-carbamoylglutamic acid can form hydrogen bonds or hydrophobic bonds with biological enzymes (such as urease and phosphatase), stabilize the conformation of the active center of the enzyme, resist the denaturing effect of high salt and high pH, ​​and ensure that biological enzymes continuously decompose organic matter and release nutrients, thereby improving fertilizer effect. This is of great significance for promoting crop production and improving economic benefits. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to specific embodiments. However, those skilled in the art should understand that the following embodiments are only for illustrating the present invention and should not be regarded as limiting the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used are all conventional products obtained through commercial channels.

[0020] In this embodiment of the invention, the preservation number of Bacillus spp. is CCTCC NO: M2022863; and the preservation number of Bacillus mucilaginosus is CGMCC 5766.

[0021] In this embodiment of the invention, the fermentation medium consists of: 10 g / L peptone, 3 g / L beef extract, 4 g / L sodium acetate, 0.5 g / L magnesium sulfate, 0.2 g / L zinc sulfate, 0.17 g / L ferric sulfate, 0.23 g / L manganese sulfate, and 3.5 g / L potassium dihydrogen phosphate; the pH of the fermentation medium is 6.5.

[0022] Example 1 A bio-enzyme compound organic fertilizer for improving saline-alkali soil comprises the following raw materials in parts by weight: 45 parts livestock and poultry manure, 11 parts compound microbial inoculant, 13 parts ferrous sulfate, 14 parts lignite, 9 parts urea, 2 parts N-carbamoylglutamic acid, 7 parts bio-enzyme, 6 parts superphosphate, and 4 parts zeolite powder. The effective viable bacteria count in the compound microbial inoculant is 4.8 × 10⁻⁶. 9 The effective viable count ratio of Bacillus mucilaginosus and Bacillus oryzae in the compound microbial agent is 1:1.2; the biological enzyme is composed of urease, phosphatase and cellulase in a mass ratio of 1:7:11.

[0023] The preparation method of the above-mentioned bio-enzyme compound organic fertilizer for saline-alkali soil improvement includes the following steps: (1) At 30℃, Bacillus mucilaginosus and Bacillus erythrophorus were activated with NA medium for 36h to obtain activated solutions; the activated solutions were inoculated into fermentation medium at an inoculation amount of 3% (v / v) and fermented at 30℃ for 48h to obtain Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth; the Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth were mixed according to the above effective viable cell ratio to obtain a compound microbial agent; (2) The lignite was crushed and screened by ball mill to obtain lignite with a particle size of 0.200 mm. The lignite was soaked in 9 mol / L nitric acid solution for 49 h, washed with deionized water until neutral, dried and sterilized to obtain pretreated coal sample; (3) Adjust the moisture content of the livestock and poultry manure to 62%, and then mix it with the pretreated coal sample, ferrous sulfate, urea, N-carbamoylglutamic acid, superphosphate and zeolite powder to obtain a mixture; (4) Add the compound microbial agent and biological enzyme to the mixture, ferment at 32°C for 11 days, turn the pile once a day, dry at low temperature to obtain pretreated fertilizer; send the pretreated fertilizer into a granulator for granulation to obtain granular fertilizer, and spray 1% coating solution (trehalose and xanthan gum are dissolved in water to prepare a 1% mass fraction solution according to the mass ratio of trehalose and xanthan gum of 1:3) for coating, and dry at low temperature.

[0024] Example 2 A bio-enzyme compound organic fertilizer for improving saline-alkali soil comprises the following raw materials in parts by weight: 40 parts livestock and poultry manure, 10 parts compound microbial agent, 10 parts ferrous sulfate, 8 parts lignite, 8 parts urea, 1 part N-carbamoylglutamic acid, 5 parts bio-enzyme, 5 parts superphosphate, and 1 part zeolite powder. The effective viable bacteria count in the compound microbial agent is 3.6 × 10⁻⁶. 9 The effective live bacteria ratio of Bacillus mucilaginosus and Bacillus oryzae in the compound microbial agent is 1:1; the biological enzyme is composed of urease, phosphatase and cellulase in a mass ratio of 1:6:10.

[0025] The preparation method of the above-mentioned bio-enzyme compound organic fertilizer for saline-alkali soil improvement includes the following steps: (1) At 30℃, Bacillus mucilaginosus and Bacillus erythrophorus were activated with NA medium for 36h to obtain activated solutions; the activated solutions were inoculated into fermentation medium at an inoculation amount of 3% (v / v) and fermented at 30℃ for 48h to obtain Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth; the Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth were mixed according to the above effective viable cell ratio to obtain a compound microbial agent; (2) The lignite was crushed and screened by ball mill to obtain lignite with a particle size of 0.125 mm. The lignite was soaked in 8 mol / L nitric acid solution for 50 h, washed with deionized water until neutral, dried and sterilized to obtain pretreated coal sample; (3) Adjust the moisture content of the livestock and poultry manure to 60%, and then mix it with the pretreated coal sample, ferrous sulfate, urea, N-carbamoylglutamic acid, superphosphate and zeolite powder to obtain a mixture; (4) Add the compound microbial agent and biological enzyme to the mixture, ferment at a constant temperature of 30°C for 12 days, turn the pile once a day, dry at low temperature to obtain pretreated fertilizer; send the pretreated fertilizer into a granulator for granulation to obtain granular fertilizer, and spray 0.5% coating solution (prepared by dissolving trehalose and xanthan gum in water according to the mass ratio of trehalose and xanthan gum of 1:3 to prepare a solution with a mass fraction of 0.5%) for coating, and dry at low temperature.

[0026] Example 3 A bio-enzyme compound organic fertilizer for improving saline-alkali soil comprises the following raw materials in parts by weight: 50 parts livestock and poultry manure, 12 parts compound microbial inoculant, 15 parts ferrous sulfate, 15 parts lignite, 12 parts urea, 3 parts N-carbamoylglutamic acid, 8 parts bio-enzyme, 9 parts superphosphate, and 5 parts zeolite powder. The effective viable bacteria count in the compound microbial inoculant is 1.2 × 10⁻⁶. 9The effective live bacteria ratio of Bacillus mucilaginosus and Bacillus oryzae in the compound microbial agent is 1:1.5; the biological enzyme is composed of urease, phosphatase and cellulase in a mass ratio of 1:8:12.

[0027] The preparation method of the above-mentioned bio-enzyme compound organic fertilizer for saline-alkali soil improvement includes the following steps: (1) At 30℃, Bacillus mucilaginosus and Bacillus erythrophorus were activated with NA medium for 36h to obtain activated solutions; the activated solutions were inoculated into fermentation medium at an inoculation amount of 3% (v / v) and fermented at 30℃ for 48h to obtain Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth; the Bacillus mucilaginosus fermentation broth and Bacillus erythrophorus fermentation broth were mixed according to the above effective viable cell ratio to obtain a compound microbial agent; (2) The lignite was crushed and screened by ball mill to obtain lignite with a particle size of 0.250 mm. The lignite was soaked in 10 mol / L nitric acid solution for 48 h, washed with deionized water until neutral, dried and sterilized to obtain pretreated coal sample; (3) Adjust the moisture content of the livestock and poultry manure to 65%, and then mix it with the pretreated coal sample, ferrous sulfate, urea, N-carbamoylglutamic acid, superphosphate and zeolite powder to obtain a mixture; (4) Add the compound microbial agent and biological enzyme to the mixture, ferment at 33°C for 10 days, turn the pile once a day, dry at low temperature to obtain pretreated fertilizer; send the pretreated fertilizer into a granulator for granulation to obtain granular fertilizer, and spray 2% coating solution (trehalose and xanthan gum are dissolved in water to prepare a 2% mass fraction solution according to the mass ratio of trehalose and xanthan gum of 1:3) for coating, and dry at low temperature.

[0028] Comparative Example 1 The difference between this comparative example and Example 1 is that Bacillus oryzae in the compound microbial agent is omitted, and the number of effective live bacteria in the organic fertilizer remains the same as in Example 1.

[0029] Comparative Example 2 The difference between this comparative example and Example 1 is that N-carbamoylglutamic acid is omitted.

[0030] Experimental Example 1 Take 10g each of the freshly prepared and room-temperature stored compound organic fertilizers obtained in the examples or comparative examples, respectively, and add them to 100mL of physiological saline. Shake at 200rpm for 2h. Determine the number of viable bacteria using the dilution plate counting method. Record the initial number of viable bacteria and the number of viable bacteria after storage, respectively, and calculate the viable bacteria retention rate using the following formula: Viable bacteria retention rate = (number of effective viable bacteria in organic fertilizer at the time of testing / number of effective viable bacteria added to organic fertilizer) × 100%, the results are shown in Table 1.

[0031] Table 1 The experimental results in Table 1 show that the compound organic fertilizers of Examples 1-3 still have a high viable bacteria retention rate after being stored at room temperature for 4 months, which is significantly higher than that of Comparative Example 2, demonstrating excellent viable bacteria survival ability and long-term stability.

[0032] Compared to Example 1, Comparative Example 2, which omitted N-carbamoylglutamic acid, showed a significant decrease in both the initial viable cell retention rate and the viable cell retention rate after 4 months of storage. This indicates that N-carbamoylglutamic acid, as an enzyme protectant, plays a crucial role in improving the survival rate of microorganisms in organic fertilizer and extending their shelf life.

[0033] Experimental Example 2 The physicochemical properties of the saline-alkali land used in the experiment are shown in Table 2.

[0034] The experiment consisted of 6 treatment groups, each covering an area of ​​2 mu (approximately 0.33 hectares). The fertilization plans for each group were as follows: Control group: Apply conventional compound fertilizer (N, P2O5, K2O ratio of 30:9:4) at a rate of 100 kg / mu; Examples 1-3 and Comparative Examples 1-2: The corresponding organic fertilizer was applied at a rate of 100 kg / mu, and conventional compound fertilizer (N, P2O5, K2O ratio of 30:9:4) was applied in addition at a rate of 20 kg / mu.

[0035] Before sowing corn, fertilizer was evenly spread on the ground according to the fertilization plan for each group, and then rotary tillers were used to till it into the soil to a depth of about 15 cm. The corn variety tested was Jingke 968, and the sowing density was 3500 plants / mu. Uniform field management methods were adopted during the corn planting period.

[0036] After the corn matured, 5 sampling points were selected in each group, and 10 corn plants were taken from each sampling point. The corn plant height of each group was counted. A 10m×10m quadrat was selected in each group to harvest the ears. After the ears were dried and threshed, the kernels were dried to determine the thousand-kernel weight and the yield was calculated. The results are shown in Table 3.

[0037] After the corn harvest, soil samples were collected from the 0-20cm soil layer near the corn roots in each group. Five sampling points were randomly selected from each group, and 1kg of mixed soil sample was collected. The soil pH was determined using a pH meter (water:soil = 5:1), the organic matter content was determined using the potassium dichromate method, and the conductivity of the extract was determined using a conductivity meter and converted to the total salt content of the soil. The results are shown in Table 3.

[0038] Table 2 Table 3 The experimental results in Table 3 show that, compared with the control group, the application of the bio-enzyme compound organic fertilizer of Examples 1-3 of this invention significantly improved the height of corn plants, the thousand-grain weight and the yield. At the same time, the soil pH and total salt content decreased, the organic matter content increased, and the effect of improving saline-alkali land was particularly outstanding.

[0039] Compared with Example 1, Comparative Example 1 showed the worst effect in improving saline-alkali land, followed by Comparative Example 2. This indicates that Bacillus oryzae plays an irreplaceable leading role in acid production, alkali reduction, and the promotion of humic acid release, while N-carbamoylglutamate, as a protective agent, also makes an important contribution to maintaining microbial activity and enzyme stability.

[0040] In summary, this invention, through the synergistic effect of Bacillus thuringiensis and multiple components such as N-carbamoylglutamic acid, can effectively improve the soil structure of saline-alkali land, significantly promote maize growth, and increase yield.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A bio-enzyme compound organic fertilizer for improving saline-alkali soil, characterized in that, The raw materials include the following parts by weight: 40-50 parts of livestock and poultry manure, 10-12 parts of compound microbial agent, 10-15 parts of ferrous sulfate, 8-15 parts of lignite, 8-12 parts of urea, 5-8 parts of biological enzyme, 5-9 parts of superphosphate, 1-3 parts of N-carbamoylglutamic acid, and 1-5 parts of zeolite powder; the compound microbial agent includes Bacillus mucilaginosus and Bacillus oryzae. The bio-enzyme is composed of urease, phosphatase and cellulase in a mass ratio of 1:(6-8):(10-12).

2. The bio-enzyme compound organic fertilizer for improving saline-alkali soil according to claim 1, characterized in that, The effective viable bacteria count in the compound microbial agent is (1-5)×10⁻⁶. 9 CFU / g; the ratio of effective viable bacteria of Bacillus mucilaginosus and Bacillus oryzae is 1:(1-1.5).

3. A method for preparing a bio-enzyme compound organic fertilizer for improving saline-alkali soil as described in claim 1, characterized in that, Includes the following steps: (1) Mix the fermentation broth of Bacillus mucilaginosus with the fermentation broth of Bacillus simulans to obtain a compound microbial agent; (2) The lignite was soaked in nitric acid solution, and then washed, dried and sterilized to obtain a pretreated coal sample; (3) After adjusting the moisture content of the livestock and poultry manure, it is then mixed with the pretreated coal sample, ferrous sulfate, urea, N-carbamoylglutamic acid, superphosphate and zeolite powder to obtain a mixture; (4) Add the compound microbial agent and biological enzyme to the mixture, ferment, dry, granulate, coat and dry.

4. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 3, characterized in that, The preparation process of Bacillus mucilaginosus fermentation broth and Bacillus simulans fermentation broth in step (1) is as follows: Bacillus mucilaginosus and Bacillus simulans are activated with NA medium and then inoculated into fermentation medium to obtain fermentation broth.

5. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 4, characterized in that, The fermentation medium consists of: 8-11 g / L peptone, 2-4 g / L beef extract, 3-5.6 g / L sodium acetate, 0.3-0.6 g / L magnesium sulfate, 0.1-0.23 g / L zinc sulfate, 0.1-0.3 g / L ferric sulfate, 0.2-0.25 g / L manganese sulfate, and 3-4.2 g / L potassium dihydrogen phosphate.

6. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 3, characterized in that, The concentration of the nitric acid solution in step (2) is 8-10 mol / L; the soaking time is 48-50 h; and the particle size of the lignite is 0.125-0.250 mm.

7. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 3, characterized in that, In step (3), the moisture content of the livestock and poultry manure is adjusted to 60-65%.

8. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 3, characterized in that, The fermentation temperature in step (4) is 30-33℃ and the time is 10-12 days.

9. The method for preparing the bio-enzyme compound organic fertilizer for saline-alkali soil improvement according to claim 3, characterized in that, The coating solution in step (4) is prepared by dissolving trehalose and xanthan gum in water at a mass ratio of 1:3 to obtain a solution with a mass fraction of 0.5-2%.

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