A high-stability synergistic ammonium chloride granular fertilizer and preparation method thereof

Abstract

The present invention discloses a highly stable synergistic ammonium chloride granular fertilizer and a preparation method thereof. The highly stable synergistic ammonium chloride granular fertilizer of the present invention is made of the following raw materials in parts by weight: 65 to 85 parts of ammonium chloride (dry ammonium), 10 to 30 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.024 to 0.48 parts of 3,4-dimethylpyrazole phosphate. The highly stable synergistic ammonium chloride granular fertilizer of the present invention can reduce the conversion rate of ammonium nitrogen to nitrate nitrogen and improve the utilization rate of nitrogen fertilizer; at the same time, the preparation process of the present invention avoids the decomposition of inhibitors in the production process, and the production process is simple, the preparation cost is low, the impact on the environment is small, and it is safe and environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizer synergistic enhancement, and particularly relates to a highly stable synergistic ammonium chloride granular fertilizer and a preparation method thereof. Background Art

[0002] In recent years, the use of nitrogen fertilizer synergists (such as nitrification inhibitors and urease inhibitors) to regulate soil nitrogen transformation and control nitrogen loss in farmland soil has become an effective measure to increase crop yield and nitrogen fertilizer utilization rate. For example, nitrification inhibitors can inhibit the activity of nitrifying bacteria in the soil, reduce the conversion of ammonium nitrogen to nitrate nitrogen, and reduce nitrogen loss and increase crop yield by changing the distribution form of nitrogen. However, a relatively large problem in the current application process is that the use effect of nitrogen fertilizer synergists shows great differences under the influence of different factors such as soil physical and chemical properties, fertilizer types, and cultivation measures, and the effect of nitrogen fertilizer synergists cannot be maximized. At present, nitrogen fertilizer synergists are mainly used in the form of stable fertilizers prepared by mixing with various fertilizer raw materials. The entire process cycle from production to application of stable fertilizers is relatively long, and a large amount of nitrogen fertilizer synergists may be lost during this period, thereby greatly reducing their application effect. Therefore, a single study of the farmland production process can no longer explain the problem of large differences in the effects of nitrogen fertilizer synergists. We need to comprehensively consider the entire process from production to application.

[0003] In order to solve the problem of unstable addition of nitrogen fertilizer synergists, some relevant studies have been conducted. CN 100360477 C discloses the use of new nitrification inhibitors and polyacids in treating inorganic fertilizers containing nitrification inhibitors. The invention uses inorganic or organic polyacids to treat nitrification inhibitors to form a new nitrification inhibitor, ensuring that the content of the nitrification inhibitor does not change significantly during storage and fertilization, and remains in the field after fertilization and plays its role. However, this study only changes the nitrification inhibitor itself, and the properties of fertilizers are complex and diverse, so only changing the nitrogen fertilizer synergist itself cannot be used for all applications. CN202010396170.1 discloses a synergist for urea-blended fertilizers and a preparation method thereof. The invention mixes n-butylthiophosphoric triamide (NBPT) solution, N-methylpyrrolidone solution, ethylene glycol, propylene glycol, water, pigments, etc. to improve the stability of the nitrogen fertilizer synergist. However, the invention only describes the use of the nitrogen fertilizer synergist alone mixed with fertilizers, and still does not propose effective measures to improve the stability of the nitrogen fertilizer synergist during the production of stable granular fertilizers.

[0004] Therefore, how to provide a stable fertilizer and its production and addition method with simple production process, high stability of nitrogen fertilizer enhancer, low preparation cost, little impact on the environment, safety and environmental protection based on the raw material formula according to different fertilizer characteristics has become a key direction urgently needed to be broken through in this field. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a highly stable synergistic ammonium chloride granular fertilizer and a preparation method thereof. The solution is to provide a stable addition method of nitrification inhibitor DMPP in ammonium chloride and a preparation method of granular fertilizer. The fertilizer granules can reduce the conversion rate of ammonium nitrogen to nitrate nitrogen, improve the utilization rate of nitrogen fertilizer, and reduce production difficulty and production cost, and reduce environmental pollution.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a highly stable synergistic ammonium chloride granular fertilizer, which is made from the following raw materials in parts by weight: 65 to 85 parts of ammonium chloride (dry ammonium), 10 to 30 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.024 to 0.48 parts of 3,4-dimethylpyrazole phosphate.

[0008] Based on the above technical scheme, firstly, the present invention can adjust the overall moisture content of the raw material by adjusting the ratio of ammonium chloride (dry ammonium) and ammonium chloride (wet ammonium), which is convenient for granulation on the one hand and improves the stability of DMPP on the other hand; secondly, since DMPP is more stable under acidic conditions, on the one hand, the present invention can adjust the overall acidity and alkalinity of the product by adding an appropriate proportion of ammonium sulfate, which is more conducive to the stability of DMPP; on the other hand, ammonium sulfate can further improve the material properties and granulation performance, so that the raw material can be better granulated.

[0009] Preferably, the high-stability synergistic ammonium chloride granular fertilizer is made from the following raw materials in parts by weight: 70 to 85 parts of ammonium chloride (dry ammonium), 10 to 25 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.024 to 0.48 parts of 3,4-dimethylpyrazole phosphate.

[0010] More preferably, the high-stability synergistic ammonium chloride granular fertilizer is made from the following raw materials in parts by weight: 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.072 parts of 3,4-dimethylpyrazole phosphate.

[0011] In the above-mentioned high-stability synergistic ammonium chloride granular fertilizer, the ammonium chloride (dry ammonium) and the ammonium chloride (wet ammonium) are both agricultural ammonium chloride (refer to national standard: GB / T2946-2018); the nitrogen mass fraction of the ammonium chloride (dry ammonium) is ≥24.5%, and the moisture content is ≤1%; the nitrogen mass fraction of the ammonium chloride (wet ammonium) is ≥23.5%, and the moisture content is ≤8.5%, such as 5%≤moisture content≤8.5%, specifically 6.5%.

[0012] In a second aspect, the present invention provides a method for preparing the high-stability synergistic ammonium chloride granular fertilizer described in any one of the above items, comprising the following steps:

[0013] S1, crushing and sieving the ammonium chloride (dry ammonium), the ammonium chloride (wet ammonium), the ammonium sulfate and the 3,4-dimethylpyrazole phosphate into powders respectively, and mixing them uniformly to obtain a powder mixture;

[0014] S2, granulating the powder mixture to obtain the highly stable synergistic ammonium chloride granular fertilizer.

[0015] In the above-mentioned preparation method, preferably, the size of the sieve hole in step S1 is 10-18 mesh, and the particle size range of each raw material is 1.00-2.00 mm. Raw materials that are too coarse or too fine are not conducive to product granulation. Too coarse raw materials will cause wear on the mechanical rollers, and too coarse raw materials will require greater extrusion energy, which is not conducive to daily granulation; too fine raw materials will affect the extrusion density, and most of them will pass through the rollers directly and cannot be granulated.

[0016] In the above preparation method, preferably, after granulation in step S2, the method further comprises: sieving to obtain particles with a particle size of 3.35 to 4.75 mm. The particle size range can make the particle size of the final product more uniform, thereby reducing the extrusion and crushing caused by the large difference in particle size during the subsequent storage and transportation of the product.

[0017] In a third aspect, the present invention provides a method for inhibiting soil nitrification, comprising the following steps: applying the high-stability enhanced ammonium chloride granular fertilizer described in any one of the above items or the high-stability enhanced ammonium chloride granular fertilizer obtained by any one of the preparation methods described in the above items to the soil.

[0018] In the above method, the amount of nitrogen applied in the application step is 0.1 to 0.3 g·kg -1 Soil, such as 0.3g kg-1 soil.

[0019] In the above method, in the application step, the high-stability enhanced ammonium chloride granular fertilizer and 3,4-dimethylpyrazole phosphate are applied together, and the mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability enhanced ammonium chloride granular fertilizer is (0.072-0.19): 100. As an example, the mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability enhanced ammonium chloride granular fertilizer is 0.072:100.

[0020] Preferably, the high-stability synergistic ammonium chloride granular fertilizer is made of the following raw materials in parts by weight: 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, 0.072-0.19 parts of 3,4-dimethylpyrazole phosphate; the mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability synergistic ammonium chloride granular fertilizer is 0.12:100. As an example, the high-stability synergistic ammonium chloride granular fertilizer is made of the following raw materials in parts by weight: 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, 0.072 parts of 3,4-dimethylpyrazole phosphate; the mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability synergistic ammonium chloride granular fertilizer is 0.12:100.

[0021] The present invention has the following beneficial effects:

[0022] The application of the invention can reduce the conversion rate of ammonium nitrogen to nitrate nitrogen and improve the utilization rate of nitrogen fertilizer. At the same time, the preparation process of the invention avoids the decomposition of the inhibitor during the production process, and the production process of the invention is simple, the preparation cost is low, the impact on the environment is small, and it is safe and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a process flow chart for preparing high-stability synergistic ammonium chloride granular fertilizer.

[0024] Figure 2 This is a curve showing the change of ammonium nitrogen content in soils with different treatments in soil culture experiment 1 in an embodiment of the present invention.

[0025] Figure 3 1 is a curve showing the change of nitrate nitrogen content in soils with different treatments in soil culture experiment 1 in an embodiment of the present invention.

[0026] Figure 4 This is a curve showing the change of soil ammonium nitrogen content in different treatments in soil culture experiment 2 in an example of the present invention.

[0027] Figure 5 1 is a curve showing the change of nitrate nitrogen content in soils with different treatments in soil culture experiment 2 in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0029] The methods used in the following examples, unless otherwise specified, are all conventional methods, carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources.

[0030] The ammonium chloride (dry ammonium) in the following embodiments has a water content of <1% and a nitrogen content of ≥25.4%, and is a product of Henan Jinshan Chemical Group; the ammonium chloride (wet ammonium) has a water content of about 6.5% and a nitrogen content of ≥23.5%, and is a product of China Salt Anhui Hongsifang Fertilizer Co., Ltd.

[0031] Example 1: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0032] The stable fertilizer of the present invention comprises, by weight ratio, 65 parts of ammonium chloride (dry ammonium), 30 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0033] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0034] 1. Weigh the raw materials, and weigh ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio. Crush and sieve the weighed materials, and the sieve size is 10 mesh to 18 mesh. The raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0035] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0036] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0037] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0038] Example 2: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0039] The stable fertilizer of the present invention comprises, by weight ratio, 70 parts of ammonium chloride (dry ammonium), 25 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0040] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0041] 1. Weigh the raw materials, and weigh ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio. Crush and sieve the weighed materials, and the sieve size is 10 mesh to 18 mesh. The raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0042] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0043] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0044] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0045] Example 3: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0046] The stable fertilizer of the present invention comprises, by weight ratio, 75 parts of ammonium chloride (dry ammonium), 20 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0047] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0048] 1. Weigh the raw materials, and weigh ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio. Crush and sieve the weighed materials, and the sieve size is 10 mesh to 18 mesh. The raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0049] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0050] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0051] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0052] Example 4: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0053] The stable fertilizer of the present invention comprises, by weight ratio, 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0054] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0055] 1. Weigh the raw materials, and weigh ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio. Crush and sieve the weighed materials, and the sieve size is 10 mesh to 18 mesh. The raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0056] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0057] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0058] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0059] Example 5: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0060] The stable fertilizer of the present invention comprises, by weight ratio, 85 parts of ammonium chloride (dry ammonium), 10 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0061] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0062] 1. Weigh the raw materials, weigh ammonium chloride (dry ammonium), the ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio, crush and sieve the weighed materials, the sieve size is 10 mesh to 18 mesh, and the raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0063] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0064] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0065] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0066] Example 6: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0067] The stable fertilizer of the present invention comprises, by weight ratio, 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.024 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0068] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0069] 1. Weigh the raw materials, weigh ammonium chloride (dry ammonium), the ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio, crush and sieve the weighed materials, the sieve size is 10 mesh to 18 mesh, and the raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0070] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0071] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0072] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0073] Example 7: Preparation of highly stable synergistic ammonium chloride granular fertilizer

[0074] The stable fertilizer of the present invention comprises, by weight ratio, 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate and 0.48 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0075] like Figure 1 As shown, the preparation process of this stable fertilizer includes the following steps:

[0076] 1. Weigh the raw materials, weigh ammonium chloride (dry ammonium), the ammonium chloride (wet ammonium), ammonium sulfate, and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio, crush and sieve the weighed materials, the sieve size is 10 mesh to 18 mesh, and the raw materials are sieved to a coarseness range of 1.00 to 2.00 mm to obtain a uniform powdered raw material.

[0077] 2. Prepare mixed powder by uniformly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), ammonium sulfate and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0078] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0079] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0080] Comparative Example 1

[0081] The fertilizer of this comparative example includes, by weight, 100 parts of ammonium chloride (wet ammonium) and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0082] The preparation process of this fertilizer includes the following steps:

[0083] 1. Weigh the raw materials, weigh ammonium chloride (wet ammonium) and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio, crush and sieve the weighed materials, the sieve size is 10 mesh to 18 mesh, the raw material coarseness range is 1.00 to 2.00 mm, and a uniform powdered raw material is obtained.

[0084] 2. Prepare mixed powder by mixing ammonium chloride (wet ammonium) and DMPP (3,4-dimethylpyrazole phosphate) evenly to form a powder mixture.

[0085] In this comparative example, the powder mixture adhered to the roller and could not be granulated.

[0086] Comparative Example 2

[0087] The fertilizer of this comparative example includes, by weight ratio: 84 parts of ammonium chloride (dry ammonium), 16 parts of ammonium chloride (wet ammonium), and 0.072 parts of DMPP (3,4-dimethylpyrazole phosphate).

[0088] The preparation process of this fertilizer includes the following steps:

[0089] 1. Weigh the raw materials, weigh ammonium chloride (dry ammonium), ammonium chloride (wet ammonium), and DMPP (3,4-dimethylpyrazole phosphate) according to the weight ratio, crush and sieve the weighed materials, the sieve size is 10 mesh to 18 mesh, the raw material coarseness range is 1.00 to 2.00 mm, and a uniform powdered raw material is obtained.

[0090] 2. Prepare mixed powder by evenly mixing ammonium chloride (dry ammonium), ammonium chloride (wet ammonium) and DMPP (3,4-dimethylpyrazole phosphate) to form a powder mixture.

[0091] 3. Granulation: Add the powder mixture into the extrusion granulator and start the extrusion granulator until all the mixed powder is extruded into granules by the machine.

[0092] 4. Screen the particles. Add the particles into a screening machine with a sieve size of 4 to 6 meshes, and screen to obtain fertilizer particles with a particle size range of 3.35 to 4.75 mm.

[0093] The effects of the present invention are described below in conjunction with specific experiments:

[0094] 1. DMPP Residual Rate of Ammonium Chloride Granular Fertilizer

[0095] The DMPP residual rate of the stable ammonium chloride granular fertilizer prepared in Examples 1-5 was determined by liquid chromatography. The experimental results are shown in Table 1.

[0096] The DMPP content in the fertilizer granules was determined according to the agricultural industry standard NY / T3423-2019 with slight modifications. The stable ammonium chloride granular fertilizer described in Examples 1-5 was prepared according to the patented formula dosage, and 5 g of each fertilizer granule sample was weighed and completely dissolved in 50 ml of water, and filtered through a 0.45 μm filter membrane. The sample solution or dilution was measured under the same conditions as the DMPP series standard solution, and the corresponding mass concentration (g / L) was found on the standard curve. The mass concentrations of the standard series solutions are: 0.03125 g / L, 0.0625 g / L, 0.0125 g / L, 0.25 g / L, and 0.5 g / L.

[0097] Column: SB-C 18 , 5μm, 250mm×4.6mm

[0098] Mobile phase: A: 0.1% trifluoroacetic acid, degassed; B: chromatography grade acetonitrile, degassed

[0099] Flow rate: 1.5ml / min

[0100] Column temperature: 30°C

[0101] Injection volume: 10 μL

[0102] Detection wavelength: 224nm

[0103] The DMPP content in the embodiment needs to calculate the production residual rate, and the specific method is as follows:

[0104] In the known embodiment, the nitrogen content of the stable ammonium chloride granular fertilizer is 24%, the sample weight is 5 g, the DMPP addition amount is 0.3% of the total nitrogen, and the DMPP standard curve is y=1707x+6.4424.

[0105] The theoretical concentration of DMPP was calculated by Equation 1;

[0106] X(g / L)=5×24%×0.3%×20, (1)

[0107] In the formula, 20 is the conversion multiple of the unit g / L;

[0108] The DMPP determination concentration was calculated by formula 2;

[0109] C(g / L)=(y i -6.442) / 1707, (2)

[0110] In the formula, y i is the peak area of ​​the i-th fertilizer particle;

[0111] Calculation method of DMPP residual rate in fertilizer granules:

[0112] η(%)=C / X,(3).

[0113] Table 1 DMPP residual rate in fertilizer granules of different embodiments

[0114]

[0115] As can be seen from Table 1, the stability of DMPP in each embodiment is good, and the residual rate is above 80%. The measured pH of the fertilizer granules of Examples 1-7 and Comparative Examples 1-2 are 5.95, 5.90, 5.87, 5.80, 5.84, 5.82, 5.79, 6.11, and 5.88, respectively, which are acidic and conducive to the stable addition of DMPP. Among them, the DMPP of the stable ammonium chloride granular fertilizer provided by Example 4 has the best stability when the addition amount is the same. In Comparative Example 1, when ammonium chloride (wet ammonium) is used for granulation, a large amount of raw materials stick to the roller of the granulator due to the high water content of the raw materials, and granulation is impossible. In addition, the pH of the raw materials is relatively high, and the stability of DMPP is poor. In Comparative Example 2, ammonium chloride (dry ammonium) and ammonium chloride (wet ammonium) are mixed in a certain proportion to reduce the overall water content of the raw materials. The pH of ammonium chloride (dry ammonium) is relatively lower than that of ammonium chloride (wet ammonium). At this time, the raw materials are easy to granulate, and the stability of DMPP is relatively improved. In Examples 1-7, some ammonium sulfate with a lower pH value is added to adjust the overall acidity and alkalinity of the product, which is more conducive to the stable addition of DMPP.

[0116] 2. Soil culture test 1

[0117] Ordinary wet ammonium refers to ammonium chloride (wet ammonium).

[0118] The soil for cultivation was obtained from the Wanzhong Experimental Station in Hefei. The soil samples were air-dried, passed through a 2 mm sieve, mixed, and placed in 100 mL white plastic bottles, with 100 g in each bottle. The nitrogen application rate was 0.3 g kg -1Soil, set up the following treatments: CK (no fertilizer), T1 (normal wet ammonium), T1+DMPP (normal wet ammonium + 0.072 parts of DMPP), T2 (Example 4 ammonium chloride), T2+DMPP (Example 4 ammonium chloride + 0.072 parts of DMPP), weigh each treatment fertilizer and mix it with the soil in the culture bottle, and each treatment is filled with 28 bottles. Place it in a constant temperature incubator at 25°C for 28 days. During the culture period, each treatment is wrapped with a water-retaining breathable film, and a few small holes are pierced with a needle to create a good aerobic environment. The relative water content is evenly maintained at 60% of the field water holding capacity, and the air-dried soil water content is 3%. Sampling was performed 7 times, and destructive sampling was performed on the 1st, 3rd, 5th, 7th, 14th, 21st and 28th days after cultivation, and the soil ammonium nitrogen and nitrate nitrogen contents were determined, and the soil apparent nitrification rate was calculated. Each sampling was repeated 4 times.

[0119] The changes in soil ammonium nitrogen content and nitrate nitrogen content under different treatments are shown in Figure 2-Figure 3 As the incubation time increased, the ammonium nitrogen content in the soil of each treatment decreased, and the nitrate nitrogen content gradually increased. The treatment with DMPP added showed a slower decrease in soil ammonium nitrogen than the treatment without DMPP. The ammonium nitrogen content in the soil was higher in the later stage of incubation, indicating that the addition of DMPP slowed down the conversion of soil ammonium nitrogen to nitrate nitrogen. On the 28th day of incubation, the nitrate nitrogen content in the soil of each treatment except the CK treatment was 47.77 mg . kg -1 、40.84mg . kg -1 、44.96mg . kg -1 、36.46mg . kg -1 , wherein the ammonium chloride treatment of the present invention has a better effect on inhibiting soil nitrification than the corresponding ordinary ammonium chloride treatment under the condition of not adding DMPP or adding DMPP.

[0120] The results of the apparent nitrification rate of soils treated with different methods are shown in Table 2. As the cultivation time increases, the apparent nitrification rate of soils treated with each method gradually increases. On the 5th day of cultivation, the apparent nitrification rate of soil treated with ammonium chloride without adding DMPP has exceeded 10%, which is significantly higher than the treatment with DMPP. On the 28th day of cultivation, except for the CK treatment, the apparent nitrification rates of soils treated with other methods were 28.95%, 20.34%, 22.23%, and 15.53%, respectively. The apparent nitrification rate of soils treated with ammonium chloride according to the present invention is significantly lower than that of soils treated with ordinary ammonium chloride, especially in the later stage of cultivation. This shows that the ammonium chloride of the present invention more effectively inhibits soil nitrification by adjusting the formula ratio.

[0121] Soil apparent nitrification rate (%) = nitrate nitrogen content / (nitrate nitrogen content + ammonium nitrogen content)*100.

[0122] Table 2 Apparent nitrification rate of soil in different treatments

[0123]

[0124] 3. Soil culture test 2

[0125] The air-dried soil sample that passed through a 2 mm sieve was mixed and placed in a 100 mL white plastic bottle, with 100 g in each bottle and a nitrogen application rate of 0.3 g kg -1 Soil, set up the following treatments: CK (no fertilizer), A1 (ammonium chloride in Example 4), A2 (ammonium chloride in Example 4 + 0.072 parts of DMPP), A3 (ammonium chloride in Example 4 + 0.12 parts of DMPP), A4 (ammonium chloride in Example 4 + 0.19 parts of DMPP), weigh each treatment fertilizer and mix it with the soil in the culture bottle, and each treatment is filled with 28 bottles. Place it in a constant temperature incubator at 25°C for 28 days. During the culture period, each treatment was wrapped with a water-retaining breathable film, and several small holes were pierced with a needle to create a good aerobic environment. The relative water content was evenly maintained at 60% of the field water holding capacity, and the air-dried soil water content was 3%. Sampling was performed 7 times, and destructive sampling was performed on the 1st, 3rd, 5th, 7th, 14th, 21st and 28th days after cultivation, with 4 replicates each time, and the soil ammonium nitrogen and nitrate nitrogen contents were determined, and the soil nitrification inhibition rate was calculated.

[0126] Nitrification inhibition rate (%) = (nitrate nitrogen in the treatment without DMPP - nitrate nitrogen in the treatment with DMPP) / nitrate nitrogen in the treatment without DMPP * 100.

[0127] The changes in soil ammonium nitrogen content and nitrate nitrogen content under different treatments are shown in Figure 4-Figure 5 . The effects of different addition amounts of DMPP and the ammonium chloride application of the present invention on the changes in soil ammonium nitrogen and nitrate nitrogen content are different. As the cultivation time increases, the ammonium nitrogen content in the soil of each treatment also decreases. The ammonium nitrogen content in the soil of the A1 treatment without DMPP addition was significantly lower than that of the treatment with DMPP addition (P < 0.05). On the 28th day of cultivation, the ammonium nitrogen content of the A2, A3 and A4 treatments was 198.06 mg . kg -1 、219.25mg . kg -1 、225.66mg . kg -1 , 26.23%, 39.73%, and 43.81% higher than the ammonium chloride treatment without DMPP. The nitrate nitrogen content in the soil of each treatment increased with the extension of the incubation time. Among them, the nitrate nitrogen content in the soil of the ammonium chloride treatment without DMPP was significantly higher than that of the treatment with DMPP added during the incubation period (P < 0.05). By the 28th day of incubation, the nitrate nitrogen content in the A2, A3, and A4 treatments was 36.46 mg. kg -1 、31.00mg . kg -1 、28.66mg . kg -1 , which were 18.91%, 31.05% and 36.25% higher than the ammonium chloride treatment without DMPP. This indicates that after adding DMPP, the conversion rate of ammonium nitrogen to nitrate nitrogen in the soil gradually decreased, so that the ammonium nitrogen content in the soil was relatively higher and the nitrate nitrogen content was lower.

[0128] The results of soil nitrification inhibition rate in different treatments are shown in Table 3. With the extension of the cultivation time, the nitrification inhibition rate of DMPP on the soil basically showed an increasing trend, and the higher the amount of DMPP added, the higher the nitrification inhibition rate of the soil. On the 28th day of cultivation, the nitrification inhibition rates of the soil in the A2, A3 and A4 treatments were 18.90%, 31.05% and 36.26%, respectively. Among them, the nitrification inhibition rate of the soil in the A2 treatment with the lowest DMPP addition also met the requirements of the nitrification inhibition rate in the GB / T35113-2017 stable fertilizer standard during the cultivation process, but the effect of the A3 treatment was significantly better than that of the A2 treatment, and there was no significant difference between the A3 and A4 treatments. Therefore, considering the cost of addition, the recommended optimal addition amount of DMPP for this product is 0.12 parts of the nitrogen content product mass.

[0129] Table 3 Soil nitrification inhibition rate under different treatments

[0130]

[0131] Since the numerical ranges of the process parameters involved in the present invention cannot be fully reflected in the above embodiments, those skilled in the art can fully imagine that any numerical value falling within the above numerical range can implement the present invention, including any combination of specific values ​​within several numerical ranges. Here, for the sake of space, the embodiments of giving specific values ​​within one or more numerical ranges are omitted, which should not be regarded as insufficient disclosure of the technical solution of the present invention.

[0132] The present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. It should be clear to those skilled in the art that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary components, specific method selection, etc., fall within the protection scope of the present invention.

Claims

1. A highly stable synergistic ammonium chloride granular fertilizer, which is made from the following raw materials in parts by weight: 65-85 parts of ammonium chloride (dry ammonium), 10-30 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.024-0.48 parts of 3,4-dimethylpyrazole phosphate.

2. The highly stable synergistic ammonium chloride granular fertilizer according to claim 1, characterized in that: It is made of the following raw materials in parts by weight: 70-85 parts of ammonium chloride (dry ammonium), 10-25 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.024-0.48 parts of 3,4-dimethylpyrazole phosphate.

3. The highly stable synergistic ammonium chloride granular fertilizer according to claim 1, characterized in that: It is made of the following raw materials in parts by weight: 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.072 parts of 3,4-dimethylpyrazole phosphate.

4. The method for preparing the highly stable synergistic ammonium chloride granular fertilizer according to any one of claims 1 to 3 comprises the following steps: S1, crushing and sieving the ammonium chloride (dry ammonium), the ammonium chloride (wet ammonium), the ammonium sulfate and the 3,4-dimethylpyrazole phosphate into powders respectively, and mixing them uniformly to obtain a powder mixture; S2, granulating the powder mixture to obtain the highly stable synergistic ammonium chloride granular fertilizer.

5. The method for preparing the highly stable synergistic ammonium chloride granular fertilizer according to claim 4, characterized in that: In step S1, the mesh size of the sieve is 10-18 mesh, and the particle size range of each raw material is 1.00-2.00 mm.

6. The method for preparing the highly stable synergistic ammonium chloride granular fertilizer according to any one of claims 4-5, characterized in that: After granulation in step S2, the method further comprises: sieving to obtain particles with a particle size of 3.35 to 4.75 mm.

7. A method for inhibiting soil nitrification, comprising the following steps: applying the high-stability synergistic ammonium chloride granular fertilizer according to any one of claims 1 to 3 or the high-stability synergistic ammonium chloride granular fertilizer obtained by the preparation method according to any one of claims 4 to 6 to the soil.

8. The method for inhibiting soil nitrification process according to claim 7, characterized in that: The nitrogen application amount in the application step is 0.1 to 0.3 g·kg -1 earth.

9. The method for inhibiting soil nitrification according to any one of claims 7-8, characterized in that: In the application step, the high-stability enhanced ammonium chloride granular fertilizer and 3,4-dimethylpyrazole phosphate are applied together, and the mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability enhanced ammonium chloride granular fertilizer is (0.072-0.19):

100.

10. The method for inhibiting soil nitrification process according to claim 9, characterized in that: The high-stability synergistic ammonium chloride granular fertilizer is made of the following raw materials in parts by weight: 80 parts of ammonium chloride (dry ammonium), 15 parts of ammonium chloride (wet ammonium), 5 parts of ammonium sulfate, and 0.072-0.19 parts of 3,4-dimethylpyrazole phosphate; The mass ratio of the 3,4-dimethylpyrazole phosphate to the high-stability synergistic ammonium chloride granular fertilizer is 0.12:100.

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