Inorganic composition sustained and controlled release synergistic compound fertilizer, preparation method thereof and corn planting method

Abstract

The invention discloses an inorganic composition sustained-release synergistic compound fertilizer which is characterized by comprising the following components in percentage by weight: 2-5% of slate tailings, 4-7% of natural zeolite, 60-75% of nitrogen fertilizer and 15-30% of potassium fertilizer. According to the inorganic composition sustained and controlled release synergistic compound fertilizer provided by the invention, the slate tailings, the natural zeolite and conventional nitrogenous fertilizer and potash fertilizer materials, especially ammonium sulfate, urea, monoammonium phosphate and potassium chloride (white) are mixed, so that the dissolution and release rate of the compound fertilizer can be improved, and the dissolution rate and water leaching loss of the compound fertilizer can be slowed down. The invention also discloses a preparation method of the fertilizer and a method for planting corn by using the fertilizer.

Description

Technical Field

[0001] This application relates to compound fertilizers and their preparation methods, and particularly to slow and controlled release compound fertilizers and their preparation methods. Background Art

[0002] Existing ordinary compound fertilizer products are characterized by fast dissolution, easy volatilization, low utilization rate, short fertilizer efficiency, and easy environmental pollution. At the same time, ordinary compound fertilizers with nitrogen, phosphorus, and potassium as the main nutrients cannot provide some essential trace elements for crop growth, such as silicon, calcium, magnesium, iron, manganese, etc.

[0003] Existing slow and controlled release compound fertilizers with enhanced efficiency often add various synthetic macro or trace elements and achieve slow release by increasing the particle size. For example, the solution disclosed in the Chinese patent application with the application number CN112898087 and the title of a slow release compound fertilizer and its preparation method. Existing slow release compound fertilizers are prepared by coating processes, such as the solutions disclosed in the Chinese patent applications with the application numbers CN114933509 and the title of slow release compound fertilizer and its preparation method, CN115197021 and the title of a modified polyacrylate coated slow release compound fertilizer and its preparation method, and CN114031457 and the title of a long - acting slow release compound fertilizer and its preparation method. However, the preparation processes in these solutions are complex, and the introduced coating substances have potential environmental pollution risks. Summary of the Invention

[0004] The first object of the present invention is to provide an inorganic composition slow and controlled release compound fertilizer with enhanced efficiency.

[0005] To achieve the above object, the present invention provides an inorganic composition slow and controlled release compound fertilizer with enhanced efficiency, comprising the following components by weight percentage: slate tailings 2% - 5%, natural zeolite 4% - 7%, nitrogen fertilizer 60% - 75%, potassium fertilizer 15% - 30%.

[0006] Preferably, the nitrogen fertilizer is a mixture of ammonium sulfate, urea, and monoammonium phosphate.

[0007] Preferably, the mixing ratio of ammonium sulfate, urea, and monoammonium phosphate is 1:2:3.4.

[0008] Preferably, the potassium fertilizer is one or a mixture of several of potassium chloride, potassium sulfate, potassium carbonate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, and potassium nitrate. The most suitable potassium fertilizer is potassium chloride, especially potassium chloride with a content of 15% to 35%.

[0009] Preferably, the inorganic composition slow-release and efficiency-enhanced compound fertilizer comprises the following components by weight percentage: slate tailings 4%, natural zeolite 7%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, potassium chloride (white) 25%.

[0010] The inorganic composition slow-release and efficiency-enhanced compound fertilizer provided by the present invention can solve the problems of conventional compound fertilizers in the following aspects: First, by compound granulation of slate tailings, natural zeolite with conventional nitrogen fertilizer and potassium fertilizer materials, especially ammonium sulfate, urea, monoammonium phosphate, potassium chloride (white), the dissolution and release rate of the compound fertilizer can be improved, and the dissolution rate and leaching loss of the compound fertilizer can be slowed down; Second, by adding slate tailings and natural zeolite, trace elements such as silicon, calcium, magnesium, iron, and manganese required for crop growth can be provided, and the comprehensive fertilizer efficiency of the compound fertilizer can be improved through the synergistic effect of multiple elements; Third, by adding slate tailings and natural zeolite, and using their adsorption and ion exchange properties, the compound fertilizer can be slowly released and the fertilizer efficiency can be prolonged; Fourth, by adding slate tailings and natural zeolite, and using their micro-particle effect, the aggregate structure of the soil can be improved, and the air permeability, water permeability of the soil and the growth characteristics of the root system can be improved.

[0011] The second object of the present invention is to provide a preparation method of the above-mentioned inorganic composition slow-release and efficiency-enhanced compound fertilizer.

[0012] To this end, the present application provides a preparation method of an inorganic composition slow-release and efficiency-enhanced compound fertilizer, which includes the steps of: respectively processing the massive slate tailings and the natural zeolite into powders with a particle size of -200 mesh accounting for ≥95%; mixing the powders of the slate tailings and the natural zeolite with the nitrogen fertilizer and the potassium fertilizer evenly to obtain a mixed dry material; mixing the mixed dry material with water accounting for 10-30% of the weight of the mixed dry material evenly to obtain a mixed wet material; performing granulation and subsequent processes on the mixed wet material to obtain the slow-release and efficiency-enhanced compound fertilizer with nearly spherical particles having a particle size of 3 mm.

[0013] Preferably, in the method, the massive slate tailings and the natural zeolite are respectively processed into powders with a particle size of -200 mesh accounting for ≥97%; the mixed dry material is mixed evenly with water accounting for 20% of the weight of the mixed dry material to obtain a mixed wet material.

[0014] The preparation method of the inorganic composition slow-release and efficiency-enhancing compound fertilizer provided by the present application is to uniformly mix powders of an inorganic material combination such as ammonium sulfate, urea, monoammonium phosphate, potassium chloride (white), slate tailings, and natural zeolite, and obtain a near-spherical slow-release and efficiency-enhancing compound fertilizer with a particle size of about 3 mm through granulation, primary screening, drying, shaping, and secondary screening. The slate tailings and natural zeolite are used to provide trace elements such as silicon, calcium, magnesium, iron, and manganese required for crop growth, and the multi-element synergistic effect is exerted to improve the comprehensive fertilizer efficiency of the compound fertilizer; the adsorption and ion exchange properties of the inorganic materials are utilized to slowly release the compound fertilizer and extend the fertilizer efficiency; the micro-particle effect of the inorganic material combination is utilized to improve the soil aggregate structure, enhance the air permeability and water permeability of the soil, and improve the growth characteristics of the root system.

[0015] Some other embodiments of the present application provide a method for planting corn with the inorganic composition slow-release and efficiency-enhancing compound fertilizer, which includes using the inorganic composition slow-release and efficiency-enhancing compound fertilizer as the base fertilizer, turning it into the plough layer of 1-20 cm according to the normal tillage system one day before farming, and the amounts of N, P2O5, and K2O are all 7.5 kg; sowing and planting corn at an appropriate time, and topdressing a commercially available compound fertilizer (15:15:15) at 20 kg per mu during the jointing stage. Description of the Drawings

[0016] Figure 1 It is a flow chart of the preparation method of the inorganic composition slow-release and efficiency-enhancing compound fertilizer according to the present application;

[0017] Figure 2 It is a flow chart of the method for planting corn with the inorganic composition slow-release and efficiency-enhancing compound fertilizer according to the present application. Detailed Embodiments

[0018] The solutions of the present application will be described in detail below with reference to the accompanying drawings.

[0019] The present invention will be further described in detail through the following specific embodiments, but it should not be understood that the scope of the present invention is limited to the following examples. Without departing from the above method concept of the present invention, various substitutions or changes made according to common general knowledge and conventional means in the art should be included in the scope of the present invention.

[0020] The slate tailings, natural zeolite, urea, ammonium sulfate, potassium chloride, monoammonium phosphate, and compound fertilizer in each embodiment and comparative example of the present application are all purchased from the conventional market.

[0021] Example 1

[0022] An inorganic composition slow-release and efficiency-enhancing compound fertilizer, comprising the following components by weight percentage: slate tailings 4%, natural zeolite 7%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, about 15 to 25% potassium chloride, namely white potassium chloride.

[0023] The preparation method of the inorganic composition slow-release and efficiency-enhancing compound fertilizer comprises the following steps:

[0024] Step S100: Process the massive slate tailings and natural zeolite respectively with a Raymond mill into powders with a particle size of -200 mesh accounting for ≥97%.

[0025] Step S200: Mix the massive slate tailings, natural zeolite powder and compound fertilizer evenly to obtain a mixed dry material.

[0026] Step S300: Mix the mixed dry material evenly with water accounting for 20% of the weight of the mixed material to obtain a mixed wet material.

[0027] Step S400: Granulate, perform primary screening, drying, shaping and secondary screening on the mixed wet material with a pair-roll extrusion granulator to obtain a slow-release and efficiency-enhancing compound fertilizer with a particle size of about 3 mm and nearly spherical shape.

[0028] In other embodiments of the above method, the water in the mixed wet material may account for 10% - 30% of the weight of the mixed material; the massive slate tailings and natural zeolite are respectively processed with a Raymond mill into powders with a particle size of -200 mesh accounting for ≥95%; the particle size of the nearly spherical slow-release and efficiency-enhancing compound fertilizer may be about 2 - 4 mm.

[0029] Example 2

[0030] An inorganic composition slow-release and efficiency-enhancing compound fertilizer, comprising the following components by weight percentage: slate tailings 6%, natural zeolite 5%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, potassium chloride (white) 25%.

[0031] The preparation method of the inorganic composition slow-release and efficiency-enhancing compound fertilizer is the same as that of Example 1.

[0032] Example 3:

[0033] An inorganic composition slow-release and efficiency-enhancing compound fertilizer, comprising the following components by weight percentage: slate tailings 5%, natural zeolite 6%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, potassium chloride (white) 25%.

[0034] The preparation method of the inorganic composition slow-release and efficiency-enhancing compound fertilizer is the same as that of Example 1.

[0035] Example 4:

[0036] A slow-release and efficiency-enhancing compound fertilizer of an inorganic composition, comprising the following components by weight percentage: slate tailings 7%, natural zeolite 4%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, potassium chloride (white) 25%.

[0037] The preparation method of the slow-release and efficiency-enhancing compound fertilizer of the inorganic composition is the same as that of Example 1.

[0038] Comparative Example 1

[0039] Do not use the above-mentioned slow-release and efficiency-enhancing compound fertilizer of the inorganic composition. Only apply a commercially available compound fertilizer per mu (the contents of N, P2O5, and K2O are 15%, 15%, and 15% respectively), and the contents of N, P2O5, and K2O are equivalent to 7.5 kg, 7.5 kg, and 7.5 kg per mu respectively.

[0040] Comparative Example 2

[0041] Do not use the slow-release and efficiency-enhancing compound fertilizer of the above-mentioned inorganic composition. Only apply a commercially available compound fertilizer per mu, and the contents of N, P2O5, and K2O are equivalent to 9.0 kg, 9.0 kg, and 9.0 kg per mu respectively.

[0042] Test method

[0043] Select a farmland in Zhaocun, Panggezhuang Town, Daxing District, Beijing as the test field, which has irrigation conditions. The soil belongs to fluvo-aquic soil, and the soil texture and the nutrient contents such as nitrogen, phosphorus, and potassium are roughly the same. A total of 6 treatment groups are set in the test, and each treatment is repeated 3 times, and the plots are randomly arranged; the area of each plot is 1 mu.

[0044] Step S801: The slow-release and efficiency-enhancing compound fertilizers of the inorganic composition prepared in Examples 1 to 4 and the commercially available compound fertilizers in Comparative Example 1 and Comparative Example 2 are all used as base fertilizers and are turned into the plough layer of 1-20 cm according to the normal farming system one day before sowing.

[0045] Step S802: Adjust the base fertilizers applied to the plots of different treatments such as Examples 1 to 4 and Comparative Example 1, and the amounts of N, P2O5, and K2O are all 7.5 kg;

[0046] For Comparative Example 2, apply a commercially available compound fertilizer, and the amounts of N, P2O5, and K2O are all 9 kg per mu;

[0047] Step S803: Machine-sow corn in early May 2021, and both the treatment group and the control group top-dress a commercially available compound fertilizer at 20 kg per mu at the jointing stage.

[0048] After the autumn harvest, measure the per-mu yield of corn kernels and the nitrogen content of corn kernels in Examples 1 to 4 and Comparative Example 1 and Comparative Example 1 according to the agricultural yield measurement rules, and the results are shown in Table 1.

[0049] Table 1 Maize Yield and Grain Nitrogen Content in Examples and Comparative Examples

[0050]

[0051]

[0052] Table 1 shows that compared with Comparative Example 1, the inorganic composition slow-release and efficiency-enhancing compound fertilizer corresponding to the examples of the present invention significantly improves both the maize yield and the grain nitrogen content. Among them, the inorganic composition slow-release compound fertilizer of Example 1 has the best effect; although the application rates of N, P2O5, and K2O in Comparative Example 2 are 20% higher than those in Examples 1 to 4 and their Comparative Example 1, its maize yield and grain nitrogen content are still lower than those in Examples 1 to 4.

Claims

1. A sustained-release and synergistic compound fertilizer of an inorganic composition, characterized in that: It comprises the following components by weight percentage: slate tailings 2% - 5%, natural zeolite 4% - 7%, nitrogen fertilizer 60% - 75%, and potassium fertilizer 15% - 30%.

2. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 1, wherein: The nitrogen fertilizer is a mixture of urea, monoammonium phosphate, and ammonium sulfate.

3. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 2, wherein: The mixing ratio of urea, monoammonium phosphate, and ammonium sulfate is 1:2:3.

4.

4. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 1, wherein: The potassium fertilizer is one or a mixture of several of potassium chloride, potassium sulfate, potassium carbonate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, and potassium nitrate.

5. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 1, characterized in that: The potassium fertilizer is potassium chloride, especially potassium chloride with a content of 15% to 35%.

6. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 1, characterized in that: It comprises the following components by weight percentage: slate tailings 4%, natural zeolite 7%, ammonium sulfate 10%, urea 20%, monoammonium phosphate 34%, and potassium chloride 25%.

7. The sustained-release and synergistic compound fertilizer of the inorganic composition according to claim 1, wherein: The inorganic composition slow-release and efficiency-enhancing compound fertilizer is in the shape of nearly spherical particles with a particle size of about 3 mm.

8. A method for preparing the inorganic composition sustained-release synergistic compound fertilizer according to any one of claims 1 to 7, characterized in that: It includes steps Processing the massive slate tailings and the natural zeolite into powders with a proportion of particles smaller than -200 mesh ≥ 95%; Mixing the powders of the slate tailings and the natural zeolite with the nitrogen fertilizer and the potassium fertilizer evenly to obtain a mixed dry material; Mixing the mixed dry material with water accounting for 10 - 30% of the weight of the mixed dry material evenly to obtain a mixed wet material; Performing granulation and subsequent processes on the mixed wet material to obtain the slow-release and efficiency-enhancing compound fertilizer in the shape of nearly spherical particles with a particle size of 2 - 4 mm.

9. The preparation method of the inorganic composition sustained-release and synergistic compound fertilizer according to claim 8, characterized in that: Processing the massive slate tailings and the natural zeolite into powders with a proportion of particles smaller than -200 mesh ≥ 97%; mixing the mixed dry material with water accounting for 20% of the weight of the mixed dry material evenly to obtain a mixed wet material; the particle size of the slow-release and efficiency-enhancing compound fertilizer in the shape of nearly spherical particles is 3 mm.

10. A method for planting corn with the inorganic composition slow-release and efficiency-enhancing compound fertilizer according to any one of claims 1 to 7, characterized in that: Using the inorganic composition slow-release and efficiency-enhancing compound fertilizer as base fertilizer and turning it into the plough layer of 1 - 20 cm according to the normal farming system one day before farming, with the amounts of N, P2O5, and K2O all being 7.5 kg; Sowing corn at an appropriate time and topdressing with 20 kg per mu of commercially available compound fertilizer (15:15:15) at the jointing stage.

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