Fertilizer based on sod and method for its production

Abstract

The application belongs to the technical field of fertilizers, and provides a fertilizer based on SOD cultivation and a preparation method thereof.The preparation method comprises the following steps: S1, according to the weight fraction, 41-45 parts of urea, 26-28 parts of potassium chloride, 22-24 parts of calcium superphosphate, 5-7 parts of bacillus subtilis spore powder, 30-32 parts of rice husk charcoal, 3-5 parts of ammonium sulfate modified magnesium-aluminum hydrotalcite and 8-10 parts of calcium chloride modified attapulgite are put into a coating machine for stirring to obtain a mixture; S2, 5-7 parts of 4wt% polyvinyl alcohol aqueous solution and 3-4 parts of distilled water are added to the mixture obtained in S1 to accelerate the granulation of the material, and granular material is obtained; and S3, the granular material obtained in S2 is subjected to drying treatment, and the fertilizer based on SOD cultivation is obtained.The application can effectively reduce the nitrogen release speed of the prepared carbon-based microbial fertilizer.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer technology, specifically relating to SOD-based fertilizers and their preparation methods. Background Technology

[0002] Fertilizers used for SOD (superoxide dismutase) cultivation primarily enhance crop SOD activity and improve the growth environment through microbial fermentation or the addition of trace elements. Carbon-based microbial fertilizers are one type of SOD-based fertilizer. In recent years, biochar, as an emerging environmental functional material, has attracted attention in the fertilizer industry due to its excellent adsorption properties, making it suitable as a nutrient carrier. Biochar is a type of refractory, stable, and highly aromatic solid material formed from biomass through high-temperature pyrolysis under anaerobic or hypoxic conditions. Biochar features a large specific surface area and high porosity, with numerous active functional groups on its surface, exhibiting excellent adsorption and strong ion exchange properties, thus improving soil anion and cation exchange capacity. As a fertilizer carrier, biochar can retain nutrients and improve fertilizer utilization.

[0003] In existing technologies, carbon-based bio-fertilizers are prepared by combining rice husk charcoal with nitrogen, phosphorus, and potassium fertilizers and Bacillus subtilis spore powder and using a mixed granulation method. As the content of rice husk charcoal increases from 0 to 30%, the total nutrients and the number of effective live bacteria in the fertilizer gradually increase, and the nitrogen release of the fertilizer becomes slower.

[0004] However, because rice husk charcoal only retains nitrogen through weak electrostatic attraction or physical adsorption via chemical bonds, and some fertilizer crystals are even merely attached to the surface of the rice husk charcoal, the slow-release effect of charcoal-based microbial fertilizers is limited. Even with the optimal slow-release effect of charcoal-based microbial fertilizers containing 30% rice husk charcoal, there is still significant room for improvement. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a fertilizer based on SOD cultivation and its preparation method, which can effectively reduce the nitrogen release rate of the prepared carbon-based microbial fertilizer and improve its slow-release effect.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a fertilizer based on SOD cultivation, comprising the following steps:

[0007] S1. By weight, add 41-45 parts of urea, 26-28 parts of potassium chloride, 22-24 parts of superphosphate, 5-7 parts of Bacillus subtilis spore powder, 30-32 parts of rice husk charcoal, 3-5 parts of ammonium sulfate modified magnesium aluminum hydrotalcite, and 8-10 parts of calcium chloride modified attapulgite to a coating machine and stir to obtain a mixture.

[0008] S2. Add (spray) 5-7 parts of 4wt% polyvinyl alcohol aqueous solution and 3-4 parts of distilled water to the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0009] S3. The particulate matter obtained in S2 is dried to obtain the fertilizer based on SOD cultivation.

[0010] Furthermore, the preparation method of the ammonium sulfate modified magnesium aluminum hydrotalcite is as follows:

[0011] A1. Place 25-30g of magnesium aluminum hydrotalcite and 3.5-3.8L of 18.2wt% ammonium sulfate solution in a container, shake several times to mix them evenly, and obtain the first solution;

[0012] A2. Place the container in a constant temperature water bath shaker, react at a constant temperature, centrifuge, collect the precipitate, and dry it to obtain the ammonium sulfate modified magnesium aluminum hydrotalcite.

[0013] Furthermore, in A2, the temperature of the constant temperature water bath is 58-60℃; the shaking speed is 200±10r / min; and the constant temperature reaction time is 3.7-4.2h.

[0014] Furthermore, in A2, the container opening is sealed with cotton to facilitate natural evaporation and dehydration.

[0015] Furthermore, the preparation method of the calcium chloride modified attapulgite is as follows:

[0016] B1. Take 4-5g of attapulgite clay, pass it through a 200-mesh sieve, add 30-40mL of 4.5wt% calcium chloride solution, stir and mix at 40±2℃ to obtain the base material;

[0017] B2. After the base material obtained in B1 is left to stand for 22-28 hours, the supernatant is removed to obtain mud. The mud is then ultrasonically treated for 5-8 minutes to obtain the calcium chloride modified attapulgite.

[0018] Furthermore, in B1, the stirring speed is 200-240 r / min, and the stirring time is 2-2.5 h.

[0019] Furthermore, in S1, the coating machine rotates at 65-70 r / min and the stirring time is 25-35 min.

[0020] Furthermore, in S3, the drying temperature is 35±2℃ and the drying time is 45-60min.

[0021] Secondly, the present invention provides a fertilizer based on SOD cultivation, which is prepared by the above-described preparation method.

[0022] This application has the following beneficial effects:

[0023] After modification with ammonium sulfate, magnesium aluminum hydrotalcite contains NH4 + It enters the interlayer of hydrotalcite and replaces the original anions (such as CO3). 2- ), to achieve NH4 + Interlayer fixation enhances nitrogen retention capacity, thereby improving the slow-release effect of fertilizer.

[0024] Calcium chloride modified attapulgite via Ca 2+ With interlayer Na + The exchange forms a positively charged modified support, and Ca 2+ The flocculation and cationic adsorption properties of attapulgite are enhanced, while rice husk char provides a porous framework, which together form a physical barrier to delay nutrient release, thereby improving the slow-release effect of fertilizer.

[0025] At the same time (under suitable conditions), Mg is released from magnesium aluminum hydrotalcite. 2+ With NH in the environment 4+ and PO4 provided by superphosphate 3- The reaction can generate slightly soluble struvite-like compounds, whose low solubility significantly reduces the nitrogen release rate; thus, it synergistically improves the slow-release effect of fertilizers based on SOD cultivation. Attached Figure Description

[0026] Figure 1 This is a comparative trend chart showing the nitrogen accumulation water dissolution rate test data of fertilizers based on SOD cultivation obtained in Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.

[0029] Example 1: (a) The preparation method of ammonium sulfate modified magnesium aluminum hydrotalcite is as follows:

[0030] A1. Place 27g of magnesium aluminum hydrotalcite and 3.6L of 18.2wt% ammonium sulfate solution in a container, shake several times to mix them evenly, and obtain the first solution.

[0031] A2. Seal the container opening with cotton to facilitate natural evaporation and dehydration; place the container in a constant temperature water bath shaker at 60℃ with a shaker speed of 200r / min, react at a constant temperature for 4 hours, centrifuge, collect the precipitate, and dry to obtain ammonium sulfate modified magnesium aluminum hydrotalcite.

[0032] (II) The preparation method of calcium chloride modified attapulgite is as follows:

[0033] B1. Take 4.5g of attapulgite clay, pass it through a 200-mesh sieve, add 35mL of 4.5wt% calcium chloride solution, and stir at 230r / min for 2.2h at 40℃ to obtain the base material.

[0034] B2. After the base material obtained in B1 is left to stand for 24 hours, the supernatant is removed to obtain mud. The mud is ultrasonically treated for 8 minutes to obtain calcium chloride modified attapulgite.

[0035] (III) A method for preparing a fertilizer based on SOD cultivation, comprising the following steps:

[0036] S1. By weight, add 43 parts of urea, 27 parts of potassium chloride, 23 parts of superphosphate, 6 parts of Bacillus subtilis spore powder, 31 parts of rice husk charcoal, 4 parts of ammonium sulfate modified magnesium aluminum hydrotalcite, and 9 parts of calcium chloride modified attapulgite into a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0037] S2. Spray 6 parts of 4wt% polyvinyl alcohol aqueous solution and 3.5 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0038] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0039] Example 2: The difference between this example and Example 1 is that: a method for preparing a fertilizer based on SOD cultivation includes the following steps:

[0040] S1. By weight, add 41 parts of urea, 28 parts of potassium chloride, 24 parts of superphosphate, 5 parts of Bacillus subtilis spore powder, 30 parts of rice husk charcoal, 3 parts of ammonium sulfate modified magnesium aluminum hydrotalcite, and 10 parts of calcium chloride modified attapulgite into a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0041] S2. Spray 5 parts of 4wt% polyvinyl alcohol aqueous solution and 4 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0042] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0043] Example 3: The difference between this example and Example 1 is that: a method for preparing a fertilizer based on SOD cultivation includes the following steps:

[0044] S1. By weight, add 45 parts of urea, 26 parts of potassium chloride, 22 parts of superphosphate, 7 parts of Bacillus subtilis spore powder, 32 parts of rice husk charcoal, 5 parts of ammonium sulfate modified magnesium aluminum hydrotalcite, and 8 parts of calcium chloride modified attapulgite into a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0045] S2. Spray 7 parts of 4wt% polyvinyl alcohol aqueous solution and 3 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0046] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0047] Comparative Example 1: The difference between this comparative example and Example 1 is that no ammonium sulfate-modified magnesium aluminum hydrotalcite and calcium chloride-modified attapulgite are added in the preparation of the fertilizer based on SOD cultivation.

[0048] Specifically, a method for preparing a fertilizer based on SOD cultivation includes the following steps:

[0049] S1. By weight, add 43 parts of urea, 27 parts of potassium chloride, 23 parts of superphosphate, 6 parts of Bacillus subtilis spore powder, and 31 parts of rice husk charcoal into a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0050] S2. Spray 6 parts of 4wt% polyvinyl alcohol aqueous solution and 3.5 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0051] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0052] Comparative Example 2: The difference between this comparative example and Example 1 is that no ammonium sulfate-modified magnesium aluminum hydrotalcite is added in the preparation of the fertilizer based on SOD cultivation.

[0053] Specifically, a method for preparing a fertilizer based on SOD cultivation includes the following steps:

[0054] S1. By weight, add 43 parts of urea, 27 parts of potassium chloride, 23 parts of superphosphate, 6 parts of Bacillus subtilis spore powder, 31 parts of rice husk charcoal, and 9 parts of calcium chloride modified attapulgite to a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0055] S2. Spray 6 parts of 4wt% polyvinyl alcohol aqueous solution and 3.5 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0056] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0057] Comparative Example 3: The difference between this comparative example and Example 1 is that calcium chloride-modified attapulgite is not added in the preparation of the fertilizer based on SOD cultivation.

[0058] Specifically, a method for preparing a fertilizer based on SOD cultivation includes the following steps:

[0059] S1. By weight, add 43 parts of urea, 27 parts of potassium chloride, 23 parts of superphosphate, 6 parts of Bacillus subtilis spore powder, 31 parts of rice husk charcoal, and 4 parts of ammonium sulfate-modified magnesium aluminum hydrotalcite into a coating machine. Stir for 30 minutes at a speed of 68 r / min to obtain a mixture.

[0060] S2. Spray 6 parts of 4wt% polyvinyl alcohol aqueous solution and 3.5 parts of distilled water into the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter.

[0061] S3. Place the granular material obtained in S2 into an oven and dry it at 35°C for 55 minutes to obtain fertilizer based on SOD cultivation.

[0062] Experimental Example: Experimental Subjects: Fertilizers prepared in Examples 1-3 and Comparative Examples 1-3. Experimental Items and Methods: The slow-release effect of each fertilizer was verified by the nitrogen cumulative water dissolution rate experiment. The specific method referred to GB / T23348-2009: Weigh 2.0g of each fertilizer sample that has passed through a 2mm sieve and place it in a nylon mesh bag with a pore size of 150μm, then seal the bag. Slowly place the mesh bag into an Erlenmeyer flask containing 200mL of distilled water, seal it with a small self-sealing bag, and place it in a constant temperature incubator at 25℃. Take a sample every 24 hours, 10mL each time, and add an equal amount of distilled water after each sample. Repeat this process 5 times. The nitrogen content of the water sample was determined using a TOC analyzer. Experimental Results: See Table 1.

[0063]

[0064] Results Analysis: Combining the data in Table 1 and... Figure 1 Analysis of Examples 1-3 shows that the cumulative nitrogen water dissolution rate of the fertilizer prepared by the present invention (Examples 1-3) is as low as 19.8% within 24 hours, indicating that the slow-release effect of the fertilizer based on SOD cultivation prepared by the present invention is good.

[0065] Combining the data in Table 1 and Figure 1Analysis of Example 1 and Comparative Examples 1-3, specifically comparing Comparative Examples 1 and 2, reveals that simply adding calcium chloride-modified attapulgite can improve the slow-release effect of the SOD-based fertilizer. Similarly, comparing Comparative Examples 1 and 3 shows that simply adding ammonium sulfate-modified magnesium aluminum hydrotalcite can also improve the slow-release effect of the SOD-based fertilizer. Furthermore, comparing with Example 1, it is evident that simultaneously adding calcium chloride-modified attapulgite and ammonium sulfate-modified magnesium aluminum hydrotalcite produces a synergistic effect, synergistically improving the slow-release effect of the SOD-based fertilizer.

[0066] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0067] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing fertilizer based on SOD cultivation, characterized in that, Includes the following steps: S1. By weight, add 41-45 parts of urea, 26-28 parts of potassium chloride, 22-24 parts of superphosphate, 5-7 parts of Bacillus subtilis spore powder, 30-32 parts of rice husk charcoal, 3-5 parts of ammonium sulfate modified magnesium aluminum hydrotalcite, and 8-10 parts of calcium chloride modified attapulgite to a coating machine and stir to obtain a mixture. S2. Add 5-7 parts of 4wt% polyvinyl alcohol aqueous solution and 3-4 parts of distilled water to the mixture obtained in S1 to accelerate the granulation of the material and obtain particulate matter. S3. The particulate matter obtained in S2 is dried to obtain the fertilizer based on SOD cultivation.

2. The method for preparing fertilizer based on SOD cultivation according to claim 1, characterized in that, The preparation method of the ammonium sulfate modified magnesium aluminum hydrotalcite is as follows: A1. Place 25-30g of magnesium aluminum hydrotalcite and 3.5-3.8L of 18.2wt% ammonium sulfate solution in a container, shake several times to mix them evenly, and obtain the first solution; A2. Place the container in a constant temperature water bath shaker, react at a constant temperature, centrifuge, collect the precipitate, and dry it to obtain the ammonium sulfate modified magnesium aluminum hydrotalcite.

3. The method for preparing fertilizer based on SOD cultivation according to claim 2, characterized in that, In A2, the temperature of the constant temperature water bath is 58-60℃; the shaking speed is 200±10r / min; and the constant temperature reaction time is 3.7-4.2h.

4. The method for preparing fertilizer based on SOD cultivation according to claim 2, characterized in that, In A2, the container opening is sealed with cotton to facilitate natural evaporation and dehydration.

5. The method for preparing fertilizer based on SOD cultivation according to claim 1, characterized in that, The preparation method of the calcium chloride modified attapulgite is as follows: B1. Take 4-5g of attapulgite clay, pass it through a 200-mesh sieve, add 30-40mL of 4.5wt% calcium chloride solution, stir and mix at 40±2℃ to obtain the base material; B2. After the base material obtained in B1 is left to stand for 22-28 hours, the supernatant is removed to obtain mud. The mud is then ultrasonically treated for 5-8 minutes to obtain the calcium chloride modified attapulgite.

6. The method for preparing fertilizer based on SOD cultivation according to claim 5, characterized in that, In B1, the stirring speed is 200-240 r / min, and the stirring time is 2-2.5 h.

7. The method for preparing fertilizer based on SOD cultivation according to claim 1, characterized in that, In S1, the coating machine rotates at 65-70 r / min and the stirring time is 25-35 min.

8. The method for preparing fertilizer based on SOD cultivation according to claim 1, characterized in that, In S3, the drying temperature is 35±2℃ and the drying time is 45-60min.

9. A fertilizer based on SOD cultivation, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.

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