Organic-inorganic mixed magnesium fertilizer as well as preparation method and application thereof

Abstract

The invention relates to an organic-inorganic mixed magnesium fertilizer and a preparation method and application thereof.The preparation method comprises the steps that a molecular sieve is acidized in an acid solution, washed and dried, then the molecular sieve is soaked in a metal ion solution, the molecular sieve is taken out, washed, dried and roasted, and a modified molecular sieve is obtained; mixing the modified molecular sieve with a magnesium-containing inorganic fertilizer raw material solution, evaporating and drying to obtain an inorganic fertilizer raw material loaded modified molecular sieve, soaking the modified molecular sieve in a polysaccharide solution, taking out and drying to obtain an inorganic fertilizer; the method comprises the following steps: mixing animal waste, plant straw and zeolite powder, inoculating a microbial agent, carrying out primary fermentation in a sealed state, and then carrying out ammonification treatment to obtain a fermented organic fertilizer; and mixing the inorganic fertilizer with the fermented organic fertilizer, and carrying out secondary fermentation. The organic and inorganic components in the fertilizer disclosed by the invention are good in synergism, nutrients are released in a balanced manner, and when the fertilizer is used for planting tobacco leaves, agronomic characters of the tobacco leaves can be improved, and smooth and stiff symptoms of the tobacco leaves are improved.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer technology, and relates to an organic-inorganic mixed magnesium fertilizer, its preparation method and application, and in particular to an organic-inorganic mixed magnesium fertilizer that improves the "smooth and stiff" symptoms of tobacco leaves, its preparation method and application. Background Technology

[0002] Fertilizers are an essential component in agricultural planting, including organic fertilizers and inorganic fertilizers.

[0003] Organic fertilizers are typically made from the composting and fermentation of livestock and poultry manure, straw, etc. They contain organic matter and provide crops with a variety of inorganic and organic nutrients while also improving soil fertility. Organic fertilizers are rich in nutrients and have a long-lasting effect, making them excellent for soil nourishment and greatly beneficial to crop growth. However, organic fertilizers have a slow-acting effect and low nutrient content, making it difficult to meet the needs of rapid crop growth.

[0004] Inorganic fertilizers (such as urea and diammonium phosphate) have simple compositions, high levels of active ingredients, are easily soluble in water, decompose quickly, and are easily absorbed by the root system. However, inorganic fertilizers lack organic matter, and long-term use can easily lead to soil compaction and decreased microbial activity.

[0005] Organic-inorganic blended fertilizers combine the advantages of both organic and inorganic fertilizers. However, most existing blended fertilizers use simple physical mixing methods, resulting in poor synergy between organic and inorganic components and uneven nutrient release. Inorganic fertilizers release nutrients quickly but for a short period; organic fertilizers release nutrients slowly and over a long period, leading to delayed fertilizer effects. The asynchronous release of these two types of fertilizers may cause nutrient imbalances, resulting in nutrient excess in the early stages of crop growth and deficiency later, or making it difficult to accurately match the crop's nutrient requirements.

[0006] In Jingxi's main tobacco-growing areas, the soil nutrients are characterized by high calcium and low magnesium, with a high calcium-to-magnesium ratio. This leads to magnesium deficiency and chlorosis in the flue-cured tobacco leaves, resulting in symptoms such as "smooth and stiff" leaves after curing. Traditional organic-inorganic mixed fertilizers are ineffective in improving these symptoms. Therefore, a suitable organic-inorganic mixed fertilizer is needed to address these issues. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide an organic-inorganic mixed magnesium fertilizer, its preparation method and application, and in particular, an organic-inorganic mixed magnesium fertilizer for improving the "smooth and stiff" symptoms of tobacco leaves, its preparation method and application.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing an organic-inorganic mixed magnesium fertilizer, the method comprising the following steps:

[0010] (1) The molecular sieve is acidified in an acid solution, washed and dried, then immersed in a metal ion solution, taken out, washed and dried, and calcined to obtain a modified molecular sieve.

[0011] The modified molecular sieve is mixed with a solution of magnesium-containing inorganic fertilizer raw material, and then evaporated and dried to obtain a modified molecular sieve loaded with inorganic fertilizer raw material. Then it is soaked in a polysaccharide solution, removed and dried to obtain inorganic fertilizer.

[0012] (2) Animal manure, plant straw and zeolite powder are mixed to obtain manure mixture, then inoculated with microbial agents, fermented in a sealed state, and then ammonified to obtain fermented organic fertilizer;

[0013] (3) Mix inorganic fertilizer with fermented organic fertilizer and carry out secondary fermentation to obtain organic-inorganic mixed magnesium fertilizer;

[0014] The order of steps (1) and (2) is not important.

[0015] This invention uses an acidified molecular sieve loaded with metal ions as a carrier to load magnesium-containing inorganic fertilizer, and further encapsulates it with polysaccharides to improve the slow-release effect of the inorganic fertilizer. Then, the loaded inorganic fertilizer is mixed with fermented organic fertilizer for secondary fermentation, so that the organic and inorganic components in the final fertilizer have good synergy and balanced nutrient release. When used in tobacco planting, it can improve the agronomic traits of tobacco leaves and improve the "smooth and stiff" symptoms of tobacco leaves.

[0016] The molecular sieve involved in this invention can be selected from conventional molecular sieve particles in the art, such as 3A molecular sieve particles (particle size 3mm).

[0017] Preferably, the calcination temperature is 300-600℃, such as 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, etc.; the calcination time is 2-3 h, such as 2 h, 2.2 h, 2.4 h, 2.5 h, 2.6 h, 2.8 h, 3 h, etc.

[0018] Preferably, the acid solution is an inorganic strong acid solution, such as hydrochloric acid.

[0019] Preferably, the concentration of the inorganic strong acid solution is 0.1-0.2 mol / L, such as 0.1 mol / L, 0.12 mol / L, 0.14 mol / L, 0.15 mol / L, 0.16 mol / L, 0.18 mol / L, 0.2 mol / L, etc.

[0020] Preferably, the acidification treatment time is 1-5 hours, such as 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, etc.

[0021] Preferably, the metal ions include Zn. 2+ and / or Fe 2+ Zn is preferred 2+ and Fe 2+ The combination of .

[0022] When using Zn 2+ and Fe 2+ When molecular sieves are modified in combination, they have a better loading effect on magnesium-containing inorganic fertilizers, resulting in better synergy between organic and inorganic components in the final fertilizer, more balanced nutrient release, and further improvement of the agronomic traits and softness of tobacco leaves.

[0023] Preferably, Zn in the metal ion solution 2+ The concentration is 0.1-0.2 mol / L, for example 0.1 mol / L, 0.12 mol / L, 0.14 mol / L, 0.16 mol / L, 0.18 mol / L, 0.2 mol / L, etc.; Fe in metal ion solution 2+ The concentration is 0.1-0.4 mol / L, for example 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, etc.

[0024] Preferably, the immersion in the metal ion solution is carried out at 40-70℃ (e.g., 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, etc.) for 10-14 h (e.g., 11 h, 12 h, 13 h, 14 h, etc.).

[0025] Preferably, the washing in step (1) is performed until neutral.

[0026] Preferably, the magnesium-containing inorganic fertilizer raw materials include magnesium sulfate or its hydrate, urea, ammonium dihydrogen phosphate, potassium nitrate, and boric acid.

[0027] Preferably, the magnesium-containing inorganic fertilizer raw materials include, by mass parts, 10-90 parts magnesium sulfate or its hydrate, 30-40 parts urea, 20-30 parts ammonium dihydrogen phosphate, 45-55 parts potassium nitrate, and 2-10 parts boric acid.

[0028] The mass fractions of magnesium sulfate or its hydrate can be selected from 10, 20, 30, 40, 50, 60, 70, 80, 90, etc.; the mass fractions of urea can be selected from 30, 32, 34, 35, 36, 38, 40, etc.; the mass fractions of ammonium dihydrogen phosphate can be selected from 20, 22, 24, 25, 26, 28, 30, etc.; the mass fractions of potassium nitrate can be selected from 45, 48, 50, 52, 53, 54, 55, etc.; and the mass fractions of boric acid can be selected from 2, 3, 4, 5, 6, 8, 10, etc.

[0029] Preferably, the solution of the magnesium-containing inorganic fertilizer raw material is a saturated solution of the magnesium-containing inorganic fertilizer raw material.

[0030] Preferably, the volume-to-mass ratio of the saturated solution to the modified molecular sieve is (3-5) mL:(1-3) g.

[0031] The specific values ​​for (3-5) mL can be 3 mL, 3.5 mL, 4 mL, 4.5 mL, 5 mL, etc.; the specific values ​​for (1-3) g can be 1 g, 1.5 g, 2 g, 2.5 g, 3 g, etc.

[0032] Preferably, the polysaccharide solution is a solution of sodium alginate and / or chitosan, more preferably a mixed solution of sodium alginate and chitosan.

[0033] When modified molecular sieves loaded with inorganic fertilizer are co-coated with sodium alginate and chitosan, the slow-release effect on magnesium-containing inorganic fertilizer is better, resulting in better synergy between organic and inorganic components in the final fertilizer, more balanced nutrient release, and further improvement of the agronomic traits and softness of tobacco leaves.

[0034] Preferably, the concentration of sodium alginate in the mixed solution is 0.1-1 g / mL, for example, 0.1 g / mL, 0.2 g / mL, 0.3 g / mL, 0.4 g / mL, 0.5 g / mL, 0.6 g / mL, 0.7 g / mL, 0.8 g / mL, 0.9 g / mL, 1 g / mL, etc.; and the concentration of chitosan is 0.1-1 g / mL, for example, 0.1 g / mL, 0.2 g / mL, 0.3 g / mL, 0.4 g / mL, 0.5 g / mL, 0.6 g / mL, 0.7 g / mL, 0.8 g / mL, 0.9 g / mL, 1 g / mL, etc.

[0035] Preferably, the volume-to-mass ratio of the mixed solution to the modified molecular sieve loaded with inorganic fertilizer raw materials is (3-5) mL:(1-3) g.

[0036] The specific values ​​for (3-5) mL can be 3 mL, 3.5 mL, 4 mL, 4.5 mL, 5 mL, etc.; the specific values ​​for (1-3) g can be 1 g, 1.5 g, 2 g, 2.5 g, 3 g, etc.

[0037] Preferably, the mass ratio of the animal manure, plant straw and zeolite powder is (100-120):(50-60):(10-30).

[0038] The specific point values ​​in (100-120) can be 100, 105, 110, 115, 120, etc.; the specific point values ​​in (50-60) can be 50, 53, 55, 58, 60, etc.; and the specific point values ​​in (10-30) can be 10, 15, 20, 25, 30, etc.

[0039] Preferably, the water content of the fecal mixture is 60-70%, such as 60%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc. (water can be added during the preparation process to adjust the water content).

[0040] Preferably, the amount of the microbial agent added is 1-2% of the fecal mixture, such as 1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 2%, etc.

[0041] Preferably, the microbial agent contains any one or a combination of at least two of yeast, Bacillus subtilis, Bacillus cereus, Aspergillus oryzae, Aspergillus niger, or Trichoderma viride.

[0042] Preferably, the microbial agents contain a combination of yeast, Bacillus subtilis, Bacillus cereus, Aspergillus oryzae, Aspergillus niger, and Trichoderma viride.

[0043] When the above-mentioned specific bacterial strain combination is used to ferment organic fertilizer and subsequent organic-inorganic mixed fertilizer, the final fertilizer has better performance in improving the agronomic traits and softness of tobacco leaves.

[0044] Preferably, the ammoniation treatment involves adding an ammonifying agent and stacking the product under sealed conditions at 20-30°C (e.g., 20°C, 23°C, 24°C, 25°C, 26°C, 28°C, 29°C, 30°C, etc.) for 10-48 hours (e.g., 10 hours, 15 hours, 18 hours, 24 hours, 30 hours, 36 hours, 40 hours, 42 hours, 48 ​​hours, etc.).

[0045] Preferably, the amount of ammoniating agent added is 5-10% of the mass of the fecal mixture, such as 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0046] Preferably, the ammoniating agent includes urea.

[0047] Preferably, the primary fermentation is carried out at 30-40℃ (e.g., 30℃, 32℃, 33℃, 34℃, 35℃, 38℃, 40℃, etc.) for 14-21 days (e.g., 14 days, 15 days, 18 days, 20 days, 21 days, etc.).

[0048] Preferably, the secondary fermentation is carried out at 20-30℃ (e.g., 20℃, 22℃, 23℃, 24℃, 25℃, 28℃, 30℃, etc.) for 7-21 days (e.g., 7 days, 10 days, 14 days, 18 days, 21 days, etc.).

[0049] Preferably, the pile is turned over every 3-4 days during the secondary fermentation process.

[0050] Preferably, after the secondary fermentation is completed, spray granulation is also performed.

[0051] Preferably, the mass ratio of the inorganic fertilizer to the fermented organic fertilizer is (10-20):(30-40).

[0052] The specific point values ​​in (10-20) can be 10, 12, 14, 15, 16, 18, 20, etc.; the specific point values ​​in (30-40) can be 30, 32, 34, 35, 36, 38, 40, etc.

[0053] Other specific point values ​​not listed above within the above numerical ranges can be selected, and all are within the protection scope of this invention. Considering the brevity of the text, they will not be described in detail here.

[0054] In a second aspect, the present invention provides an organic-inorganic mixed magnesium fertilizer prepared according to the preparation method described in the first aspect.

[0055] Thirdly, the present invention provides the application of the organic-inorganic mixed magnesium fertilizer according to the second aspect in flue-cured tobacco cultivation.

[0056] Preferably, in the application, the application rate of the organic-inorganic mixed magnesium fertilizer is 180-420 kg·hm², based on the amount of magnesium salt (e.g., magnesium sulfate or its hydrate). −2 More preferably 280-320 kg·hm −2 .

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] This invention uses an acidified molecular sieve loaded with metal ions as a carrier to load magnesium-containing inorganic fertilizer, and further encapsulates it with polysaccharides to improve the slow-release effect of the inorganic fertilizer. Then, the loaded inorganic fertilizer is mixed with fermented organic fertilizer for secondary fermentation, so that the organic and inorganic components in the final fertilizer have good synergy and balanced nutrient release. When used in tobacco planting, it can improve the agronomic traits of tobacco leaves, improve the "smooth and stiff" symptoms of tobacco leaves, and enhance the softness of tobacco leaves. Detailed Implementation

[0059] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0060] The molecular sieves mentioned below are 3A molecular sieve particles (3mm in diameter); the plant straw is a mixture of rice straw and corn straw; the microbial inoculant is composed of yeast, Bacillus subtilis, Bacillus cereus, Aspergillus oryzae, Aspergillus niger, and Trichoderma viride in a bacterial count ratio of 2:3:1:2:1:1.

[0061] Example 1

[0062] This embodiment provides an organic-inorganic mixed magnesium fertilizer, the preparation method of which is as follows:

[0063] (1) The molecular sieve was acidified in 0.15 mol / L HCl solution for 3 h, washed until neutral and dried, and then immersed in Zn. 2+ The concentration was 0.17 mol / L, Fe 2+ The modified molecular sieve was adsorbed by shaking at 60°C for 12 h in a metal ion solution with a concentration of 0.34 mol / L, washed and dried, and then calcined at 500°C for 2.5 h to obtain the modified molecular sieve.

[0064] (2) Weigh out 35 parts of urea, 25 parts of diammonium phosphate, 50 parts of potassium nitrate, 7 parts of boric acid, and 39 parts of magnesium sulfate heptahydrate according to the mass ratio to obtain inorganic fertilizer raw materials, and prepare a saturated solution. Mix the saturated solution with the modified molecular sieve at a volume mass ratio of 5 mL: 2 g. After evaporation and drying, obtain the molecular sieve loaded with inorganic fertilizer. Then soak it in a mixed solution with a sodium alginate concentration of 0.3 g / mL and a chitosan concentration of 0.3 g / mL, wherein the volume mass ratio of the mixed solution to the molecular sieve loaded with inorganic fertilizer is 5 mL: 2 g. Take it out and dry it to obtain inorganic fertilizer.

[0065] (3) Mix animal manure, plant straw and zeolite powder in a mass ratio of 110:55:20 and adjust the moisture content to obtain a manure mixture with a moisture content of 65%. Then add 1.4% of the manure mixture by mass of compound microbial agent solution and stir evenly. Ferment at 35°C for 3 weeks in a sealed state. Then add 7% of the manure mixture by mass of urea and pile at 25°C for 20 hours for ammoniation treatment to obtain fermented organic fertilizer.

[0066] (4) Mix the inorganic fertilizer obtained in step (2) and the fermented organic fertilizer in step (3) at a mass ratio of 12:38. Then, pile them at 25°C for 3 weeks for secondary fermentation. After fermentation, spray granulation is carried out to obtain organic-inorganic mixed magnesium fertilizer.

[0067] Example 2

[0068] This embodiment provides an organic-inorganic mixed magnesium fertilizer. The difference between its preparation method and that of Embodiment 1 is that in step (2), 35 parts of urea, 25 parts of diammonium phosphate, 50 parts of potassium nitrate, 7 parts of boric acid, and 65 parts of magnesium sulfate heptahydrate are weighed according to the mass ratio to obtain inorganic fertilizer raw materials; in step (4), the mass ratio of inorganic fertilizer to fermented organic fertilizer is 14:36. Other conditions remain unchanged.

[0069] Example 3

[0070] This embodiment provides an organic-inorganic mixed magnesium fertilizer. The difference between its preparation method and that of Embodiment 1 is that in step (2), 35 parts of urea, 25 parts of diammonium phosphate, 50 parts of potassium nitrate, 7 parts of boric acid, and 91 parts of magnesium sulfate heptahydrate are weighed according to the mass ratio to obtain inorganic fertilizer raw materials; in step (4), the mass ratio of inorganic fertilizer to fermented organic fertilizer is 16:34. Other conditions remain unchanged.

[0071] Example 4

[0072] This embodiment provides an organic-inorganic mixed magnesium fertilizer. The difference between its preparation method and that of Embodiment 1 is that in step (2), 35 parts of urea, 25 parts of diammonium phosphate, 50 parts of potassium nitrate, 7 parts of boric acid, and 13 parts of magnesium sulfate heptahydrate are weighed according to the mass ratio to obtain inorganic fertilizer raw materials; in step (4), the mass ratio of inorganic fertilizer to fermented organic fertilizer is 10:40. Other conditions remain unchanged.

[0073] Test case

[0074] The organic-inorganic mixed magnesium fertilizer prepared in Examples 1-4 of this invention was used in a field trial of flue-cured tobacco K326. The specific method is as follows:

[0075] Experiments were conducted in Huadong Town, Jingxi City, Guangxi Province, with different soil physicochemical properties (medium-calcium plot A, relatively high-calcium plot B, and extremely high-calcium plot C). The specific soil physicochemical properties are shown in Table 1.

[0076] Table 1

[0077]

[0078] The field trial was conducted in 2024, using flue-cured tobacco variety K326. Floating seedling raising was employed, and seedlings were transplanted in mid-February 2024. Each treatment consisted of three plots, with 50 tobacco plants per plot, spaced 120 cm apart in rows and 50 cm apart in plants, with a protective row. This trial employed a randomized block design, dividing each plot into four treatment groups. The total fertilizer application rate remained consistent across all treatment groups: Example 1 group (using the fertilizer prepared in Example 1, at 180 kg·hm²). −2 Magnesium sulfate heptahydrate fertilization), Example 2 group (using the fertilizer prepared in Example 2, at 300 kg·hm −2 Magnesium sulfate heptahydrate fertilization), Example 3 group (using the fertilizer prepared in Example 3, at 420 kg·hm −2 Magnesium sulfate heptahydrate fertilization), Example 4 group (using the fertilizer prepared in Example 4, at 60 kg·hm −2 Magnesium sulfate heptahydrate was applied uniformly to all groups during the basal fertilizer period, and topdressing was carried out 45 days after transplanting, with a topdressing rate of 150 kg·hm². −2 Potassium nitrate was used as a top dressing, and no further fertilizer was applied. During the maturity stage of flue-cured tobacco growth, the agronomic traits of different plots were characterized.

[0079] The agronomic traits of flue-cured tobacco in each treatment group in medium-calcium plot A are shown in Table 2 (the same letter indicates no significant difference, different letters indicate significant differences (p<0.05), and those without letters indicate no significant difference).

[0080] Table 2

[0081]

[0082] Meanwhile, the softness of flue-cured tobacco in each treatment group in medium-calcium plot A was measured. The flue-cured tobacco samples were placed at 22℃ and 65% relative humidity for 72 h for equilibration treatment, and the softness of the flue-cured tobacco was measured using Handle-O-Meter (T / A-Thwing-Albert). The results are shown in Table 3.

[0083] Table 3

[0084]

[0085] As can be seen from the data results in Tables 2 and 3, after treatment with the organic-inorganic mixed magnesium fertilizer involved in this invention, the overall agronomic traits of flue-cured tobacco in medium-calcium plots are excellent, and the tobacco leaves have low softness values ​​and good softness. Among them, the effect of Example 2 is even better.

[0086] The agronomic traits of flue-cured tobacco in each treatment group in the high-calcium plot B are shown in Table 4 (the same letter indicates no significant difference, different letters indicate significant differences (p<0.05), and those without letters indicate no significant difference).

[0087] Table 4

[0088]

[0089] Meanwhile, the softness of flue-cured tobacco in each treatment group in plot B with higher calcium content was measured. The flue-cured tobacco samples were placed at 22℃ and 65% relative humidity for 72 h for equilibration treatment, and the softness of the flue-cured tobacco was measured using Handle-O-Meter (T / A-Thwing-Albert). The results are shown in Table 5.

[0090] Table 5

[0091]

[0092] As can be seen from the data in Tables 4 and 5, after treatment with the organic-inorganic mixed magnesium fertilizer involved in this invention, the overall agronomic traits of flue-cured tobacco in high-calcium plots are excellent, and the tobacco leaves have low softness values ​​and good softness. Among them, the effect of Example 2 is even better.

[0093] The agronomic traits of flue-cured tobacco in each treatment group in the extremely high calcium plot C are shown in Table 6 (the same letter indicates no significant difference, different letters indicate significant differences (p<0.05), and those without letters indicate no significant difference).

[0094] Table 6

[0095]

[0096] Meanwhile, the softness of flue-cured tobacco in each treatment group of the extremely high-calcium plot C was measured. The flue-cured tobacco samples were placed at 22℃ and 65% relative humidity for 72 h for equilibration treatment, and the softness of the flue-cured tobacco was measured using Handle-O-Meter (T / A-Thwing-Albert). The results are shown in Table 7.

[0097] Table 7

[0098]

[0099] The data in Tables 6 and 7 show that the organic-inorganic mixed magnesium fertilizer treatment involved in this invention resulted in excellent overall agronomic traits of flue-cured tobacco in extremely high-calcium plots, with low leaf softness values ​​and good tenderness. Example 2 showed even better results.

[0100] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0101] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0102] 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.

Claims

1. A method for preparing an organic-inorganic hybrid magnesium fertilizer, characterized by, The preparation method comprises the following steps: (1) acidizing treatment of molecular sieve in acid solution, washing and drying, then soaking in metal ion solution, taking out, washing and drying, calcination treatment, to obtain modified molecular sieve; Mixing the modified molecular sieve with the solution of magnesium-containing inorganic fertilizer raw material, evaporating and drying to obtain modified molecular sieve loaded with inorganic fertilizer raw material, then soaking in polysaccharide solution, taking out and drying to obtain inorganic fertilizer; (2) mixing animal manure, plant straw and zeolite powder to obtain manure mixture, then inoculating microbial inoculum, carrying out primary fermentation in a sealed state, then carrying out ammoniation treatment to obtain fermented organic fertilizer; (3) mixing inorganic fertilizer with fermented organic fertilizer, carrying out secondary fermentation to obtain organic-inorganic mixed magnesium fertilizer; The steps (1) and (2) are not distinguished in sequence.

2. The production method according to claim 1, characterized by, The temperature of the calcination treatment is 300-600℃, and the time of the calcination treatment is 2-3 h; Preferably, the acid solution is inorganic strong acid solution; Preferably, the acid concentration of the inorganic strong acid solution is 0.1-0.2 mol / L; Preferably, the time of the acidizing treatment is 1-5 h.

3. The production method according to claim 1 or 2, characterized by, the metal ions comprise Zn 2+ and / or Fe 2+ , more preferably Zn 2+ and Fe 2+ in combination; Preferably, Zn in the metal ion solution 2+ The concentration is 0.1-0.2 mol / L, Fe in the metal ion solution 2+ The concentration is 0.1-0.4 mol / L; Preferably, the soaking in metal ion solution is carried out at 40-70℃ for 10-14 h.

4. The production method according to any one of claims 1 to 3, characterized by, The magnesium-containing inorganic fertilizer raw material comprises magnesium sulfate or hydrate thereof, urea, ammonium dihydrogen phosphate, potassium nitrate, boric acid; Preferably, the magnesium-containing inorganic fertilizer raw material comprises magnesium sulfate or hydrate thereof 10-90 parts, urea 30-40 parts, ammonium dihydrogen phosphate 20-30 parts, potassium nitrate 45-55 parts, boric acid 2-10 parts in terms of mass fraction; Preferably, the solution of the magnesium-containing inorganic fertilizer raw material is a saturated solution of the magnesium-containing inorganic fertilizer raw material; Preferably, the volume-mass ratio of the saturated solution to the modified molecular sieve is (3-5) mL:(1-3) g.

5. The production method according to any one of claims 1 to 4, characterized by, The polysaccharide solution is a solution of sodium alginate and / or chitosan, more preferably a mixed solution of sodium alginate and chitosan; Preferably, the concentration of sodium alginate in the mixed solution is 0.1-1 g / mL, and the concentration of chitosan is 0.1-1 g / mL; Preferably, the volume-mass ratio of the mixed solution to the modified molecular sieve loaded with inorganic fertilizer raw material is (3-5) mL:(1-3) g.

6. The production method according to any one of claims 1 to 5, characterized by, The mass ratio of the animal manure, plant straw and zeolite powder is (100-120):(50-60):(10-30); Preferably, the water content of the manure mixture is 60-70%; Preferably, the addition amount of the microbial inoculum is 1-2% of the manure mixture.

7. The production method according to any one of claims 1 to 6, characterized by, The bacteria in the microbial inoculum comprise any one or a combination of at least two of yeast, Bacillus subtilis, Bacillus cereus, Aspergillus oryzae, Aspergillus niger or Trichoderma viride; Preferably, the bacteria in the microbial inoculum comprise a combination of yeast, Bacillus subtilis, Bacillus cereus, Aspergillus oryzae, Aspergillus niger and Trichoderma viride.

8. The production method according to any one of claims 1 to 7, characterized by, The ammoniation treatment is adding ammoniation agent for 10-48 h at 20-30℃ under sealed conditions; Preferably, the addition amount of the ammoniation agent is 5-10% of the mass of the manure mixture; Preferably, the ammoniation agent comprises urea; Preferably, the primary fermentation is carried out at 30-40℃ for 14-21 days; Preferably, the secondary fermentation is carried out at 20-30℃ for 7-21 days; Preferably, the mass ratio of the inorganic fertilizer to the fermented organic fertilizer is (10-20):(30-40).

9. The organic-inorganic mixed magnesium fertilizer prepared by the preparation method according to any one of claims 1-8.

10. The organic-inorganic mixed magnesium fertilizer according to claim 9 for use in the cultivation of flue-cured tobacco.

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