High-temperature-resistant DMPP composite preparation as well as preparation method and application thereof

Abstract

The invention discloses a high-temperature-resistant DMPP composite preparation as well as a preparation method and application thereof, and belongs to the technical field of nitrogen fertilizer synergistic materials. The composite preparation is prepared from the following raw materials in parts by weight: 40 to 50 parts of high-molecular compound, 20 to 40 parts of acidic substance, 0.5 to 2.5 parts of lignin sulfonate and 5 to 40 parts of 3, 4-dimethyl pyrazole phosphate DMPP. The compound preparation has good high-temperature resistance and can keep stable chemical properties in the high-temperature granulation process of the fertilizer. In practical application, when the high-temperature-resistant DMPP composite preparation is directly added into fertilizer slurry for high-tower granulation, the stability of DMPP in a high-temperature environment can be ensured, and the decomposition and loss of DMPP caused by high temperature are avoided, so that the effective content of DMPP in a finished product fertilizer is ensured. The problems that the DMPP fertilizer is low in external adding efficiency, the production process is complex, and the cost is additionally increased are solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nitrogen fertilizer synergistic materials, and particularly relates to a high-temperature-resistant DMPP composite preparation and a preparation method and application thereof. BACKGROUND

[0002] DMPP (3,4-dimethyl pyrazole phosphate) is a white crystal or solid powder, is acidic, is a high-quality, efficient and low-toxicity nitrification inhibitor. By adding the nitrification inhibitor DMPP in the fertilizer according to the principle of soil colloid adsorbing ammonium ions, the activity of nitrification and denitrification bacteria in the soil can be effectively inhibited, the rate of conversion of ammonium nitrogen to nitrate nitrogen is delayed, and thus the utilization rate of chemical fertilizer is improved, and the crop quality is improved and environmental pollution is reduced.

[0003] At present, the main type of fertilizer is still compound fertilizer, and improving the nutrient utilization rate of compound fertilizer is still the key research and development direction, but how to add DMPP in the compound fertilizer is still a problem. According to the physical and chemical properties of DMPP, DMPP is not resistant to high temperature, is easy to react with substances in the fertilizer, produce volatile substance DMP, cause loss, and is not suitable for adding in the granulation process.

[0004] The prior art is to solve the problem of instability of DMPP at high temperature, and DMPP is usually coated on the surface of the granules at the tail end of the fertilizer granulation, which needs to additionally increase equipment and increase cost, and the external addition of DMPP is wrapped on the surface of the fertilizer granules, which brings great safety hazards to farmers in the use process.

[0005] In addition, the nitrification inhibitor is also a method after treatment, for example, Chinese patent CN108017478A discloses a polyphenol coated nitrification inhibitor and a preparation method and application thereof, the method has complex manufacturing process, and it is not clear whether the nitrification inhibitor has high-temperature-resistant effect and whether DMPP can be directly added in the high tower granulation process.

[0006] For example, Chinese patent CN109665927A discloses a stable nitrification inhibitor and a preparation method and application thereof, the method is to dissolve starch and colloid in water and spray dry to obtain the stable nitrification inhibitor, and similarly, the stable nitrification inhibitor introduced in the patent is mixed with the fertilizer, is suitable for solid water-soluble fertilizer and liquid fertilizer, and cannot meet the high-temperature granulation demand of compound fertilizer in the high tower and the roller process. And the traditional mixing method is to directly mix DMPP with the finished fertilizer, which is easy to cause uneven distribution and physical separation (such as DMPP concentrated in the lower layer after transportation).

[0007] Therefore, how to develop a high-temperature-resistant DMPP composite preparation, which can be directly added in the high-temperature granulation process of compound fertilizer, does not increase additional equipment and cost, can guarantee the safety of use, and at the same time meets the production needs of compound fertilizer of high tower and roller process, improves the production efficiency and reduces the cost, has become the problem to be solved in the current nitrogen fertilizer efficiency material technology field. SUMMARY

[0008] The purpose of the present application is to provide a high-temperature-resistant DMPP, which can not only solve the problems of low efficiency of external addition of fertilizer, complex production process, additional cost, etc., but also guarantee the safety of use by farmers, and also has the advantages of simple preparation method, low cost, convenient use, etc.

[0009] To achieve the above technical purposes, the technical scheme adopted by the present application is: A high-temperature-resistant DMPP composite preparation, comprising the following raw materials by weight: 40-50 parts of a high molecular compound, 20-40 parts of an acidic substance, 0.5-2.5 parts of sulfonated lignin, and 25-40 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0010] Preferably, the high molecular compound is starch and / or cellulose.

[0011] More preferably, the cellulose is hydroxypropyl methyl cellulose.

[0012] Preferably, the acidic substance is at least one of urea phosphate, urea sulfate, and citric acid.

[0013] Preferably, the amount of the high molecular compound is greater than that of the acidic substance.

[0014] A preparation method of a high-temperature-resistant DMPP composite preparation, comprising the following steps: (a) mixing the acidic substance, the sulfonated lignin, and the DMPP at room temperature for 10-20 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160 DEG C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0015] A high-temperature-resistant DMPP composite preparation in the application of high-temperature granulation of fertilizer, the preparation is directly added to the fertilizer slurry, and the finished fertilizer is obtained after high-tower granulation.

[0016] The present application realizes the efficient protection of DMPP in high-temperature granulation through the triple synergistic mechanism of acidic substance-high molecular compound-sulfonated lignin, and the specific effects are as follows: (1) First, add acidic substances (urea phosphate / sulfate / citric acid), which are liquefied and foamed at high temperatures to form a liquid microenvironment to wrap DMPP. On the one hand, it acts as a carrier to carry DMPP, and on the other hand, the acidic environment it provides can inhibit the hydrolysis of DMPP; (2) Second, add high molecular compounds, such as starch or cellulose, which can absorb heat when hydrolyzed in an acidic environment at high temperatures, consume system heat energy, and reduce DMPP loss; (3) Finally, add sulfonated lignin as a functional additive. Its sulfonic acid group (-SO3H) ionizes to anion (-SO3⁻) in an acidic environment. -SO3⁻ and high molecular compounds form a hydrogen bond network through hydrogen bond interaction, enhancing the stability of the wrapping layer and effectively blocking the diffusion of DMPP outward. Sulfonated lignin itself is a dispersant that increases slurry flowability while adsorbing on the surface of DMPP particles, using steric hindrance and charge repulsion to improve the dispersibility of DMPP in the entire system, making DMPP more evenly dispersed.

[0017] (4) Thus, the synergistic effect of acidic substances, high molecular compounds, and sulfonated lignin achieves high-temperature protection of DMPP formulations. This high-temperature protection mechanism gives the composite formulation a significant advantage in the high-temperature granulation process of fertilizers. In practical applications, using this high-temperature-resistant DMPP composite formulation directly added to the fertilizer slurry for high-tower granulation can ensure the stability of DMPP in a high-temperature environment, avoiding DMPP decomposition and loss due to high temperature, thereby ensuring the effective content of DMPP in the finished fertilizer. Moreover, the porous granular structure formed by the composite formulation helps it disperse and function better in the soil, further improving the nutrient utilization rate of the fertilizer and providing a more efficient nitrogen fertilizer efficiency solution for agricultural production. At the same time, since no additional equipment is needed to handle the addition of DMPP, production costs are reduced, and safety hazards for farmers during use are also reduced, bringing convenience and good economic benefits to the production and use of compound fertilizers. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Effect picture of the first batch of pot planting experiment; Figure 2 Effect picture of the second batch of pot planting experiment; Figure 3 Effect picture of the third batch of pot planting experiment. DETAILED DESCRIPTION

[0019] The technical solutions of the present application are further described below in conjunction with specific embodiments, but are not limited thereto.

[0020] Example 1 A high-temperature-resistant DMPP composite preparation, comprising the following raw materials by weight: 50 parts of a high-molecular compound, 40 parts of an acidic substance, 2 parts of sulfonated lignin, and 25 parts of 3,4-dimethylpyrazole phosphate (DMPP).

[0021] The high-molecular compound is cellulose.

[0022] The acidic substance is urea sulfate.

[0023] A preparation method of a high-temperature-resistant DMPP composite preparation, comprising the following steps: (a) mixing the acidic substance, the sulfonated lignin, the high-molecular compound, and the DMPP at room temperature for 10 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0024] Example 2 A high-temperature-resistant DMPP composite preparation, comprising the following raw materials by weight: 40 parts of a high-molecular compound, 30 parts of an acidic substance, 0.5 parts of sulfonated lignin, and 30 parts of 3,4-dimethylpyrazole phosphate (DMPP).

[0025] The high-molecular compound is starch.

[0026] The acidic substance is urea phosphate.

[0027] A preparation method of a high-temperature-resistant DMPP composite preparation, comprising the following steps: (a) mixing the acidic substance, the sulfonated lignin, the high-molecular compound, and the DMPP at room temperature for 10 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0028] Example 3 A high-temperature-resistant DMPP composite preparation, comprising the following raw materials by weight: 50 parts of a high-molecular compound, 40 parts of an acidic substance, 2.5 parts of sulfonated lignin, and 40 parts of 3,4-dimethylpyrazole phosphate (DMPP).

[0029] The cellulose is hydroxypropyl methyl cellulose.

[0030] The acidic substance is urea sulfate.

[0031] A preparation method of a high-temperature-resistant DMPP composite preparation, comprising the following steps: (a) mixing the acidic substance, the sulfonated lignin, the high molecular compound and the DMPP at normal temperature for 10 minutes to form a premix; (b) then high-temperature processing through a double screw extruder to form the DMPP composite preparation, wherein the discharge temperature of the double screw extruder is 160°C, the rotating speed is 60 r / min, and the feeding frequency is 10 Hz.

[0032] Example 4 The high-temperature resistant DMPP composite preparation comprises the following raw materials in parts by weight: 40 parts of the high molecular compound, 20 parts of the acidic substance, 1 part of the sulfonated lignin, and 35 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0033] The high molecular compound is cellulose.

[0034] The acidic substance is urea phosphate.

[0035] A preparation method of the high-temperature resistant DMPP composite preparation comprises the following steps: (a) mixing the acidic substance, the sulfonated lignin, the high molecular compound and the DMPP at normal temperature for 20 minutes to form a premix; (b) then high-temperature processing through a double screw extruder to form the DMPP composite preparation, wherein the discharge temperature of the double screw extruder is 160°C, the rotating speed is 60 r / min, and the feeding frequency is 10 Hz.

[0036] Comparative Example 1 In this comparative example, the raw materials and process steps are the same as those in Example 1 except that the high molecular compound is not used. That is: A DMPP composite preparation comprises the following raw materials in parts by weight: 90 parts of the acidic substance, 2 parts of the sulfonated lignin, and 25 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0037] The acidic substance is urea sulfate.

[0038] A preparation method of the DMPP composite preparation comprises the following steps: (a) mixing the acidic substance, the sulfonated lignin and the DMPP at normal temperature for 10 minutes to form a premix; (b) then high-temperature processing through a double screw extruder to form the DMPP composite preparation, wherein the discharge temperature of the double screw extruder is 160°C, the rotating speed is 60 r / min, and the feeding frequency is 10 Hz.

[0039] Comparative Example 2 In this comparative example, the raw materials and process steps are the same as those in Example 1 except that the acidic substance is not used. That is: A DMPP composite preparation, comprising the following raw materials by weight: 90 parts of a high molecular compound, 2 parts of sulfonated lignin, and 25 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0040] The high molecular compound is cellulose.

[0041] A preparation method of a DMPP composite preparation, comprising the following steps: (a) mixing sulfonated lignin, a high molecular compound, and DMPP at room temperature for 10 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0042] Comparative Example 3 In this comparative example, referring to Example 1, except that ordinary lignin is used to replace sulfonated lignin, the remaining raw materials and process steps are the same as those in Example 1. That is: A DMPP composite preparation, comprising the following raw materials by weight: 50 parts of a high molecular compound, 40 parts of an acidic substance, 2 parts of lignin, and 25 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0043] The high molecular compound is cellulose.

[0044] The acidic substance is urea sulfate.

[0045] A preparation method of a DMPP composite preparation, comprising the following steps: (a) mixing an acidic substance, lignin, a high molecular compound, and DMPP at room temperature for 10 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0046] Comparative Example 4 In this comparative example, referring to Example 1, except that the addition amount of the acidic substance is increased, that is, the addition amount of the high molecular compound is less than that of the acidic substance, the remaining raw materials and process steps are the same as those in Example 1. That is: A DMPP composite preparation, comprising the following raw materials by weight: 40 parts of a high molecular compound, 50 parts of an acidic substance, 2 parts of sulfonated lignin, and 25 parts of 3,4-dimethylpyrazole phosphate DMPP.

[0047] The high molecular compound is cellulose.

[0048] The acidic substance is urea sulfate.

[0049] A preparation method of DMPP composite preparation, comprising the following steps: (a) mixing the acidic substance, sulfonated lignin, high molecular compound and DMPP at room temperature for 10 min to form a premix; (b) then high-temperature processing through a double-screw extruder to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

[0050] Comparative Example 5 The nitrification inhibitor was prepared according to Chinese Patent CN109665927A. The preparation was carried out according to the method of Example 1 in the disclosed technical solution: A stable nitrification inhibitor, wherein the mass ratio of DMPP, gum arabic powder, gelatin and soluble starch in the nitrification inhibitor is 1:2:1:2.

[0051] The preparation method of the above stable nitrification inhibitor, comprising the following steps: (1) according to the mass ratio, DMPP, gum arabic powder, gelatin and soluble starch are added to 50°C water, stirred for 2h, so that they are completely dissolved and mixed, to prepare a solution with a total mass content of 20%; (2) the solution obtained in step (1) is spray dried to obtain a stable nitrification inhibitor, wherein the inlet air temperature is 140°C, the outlet temperature is 70°C, and the feeding speed is 2L / h.

[0052] Performance test Laboratory simulation: Simulate high tower granulation, first prepare a beaker, put the prepared nitrogen, phosphorus and potassium fertilizer with a proportion of 14-5-26 into the beaker and heat to melt the slurry (at this time the slurry temperature is about 162°C), then add pure DMPP and the preparations of Examples 1-4 and Comparative Examples 1-5 to the respective beakers, respectively, and then stir for 3 minutes, 5 minutes, 10 minutes, 15 minutes and 30 minutes, respectively, take out and detect the DMPP recovery loss rate. Each group of experiments is repeated 5 times, and the average value is taken. The detection method refers to NY / T 3423-2019.

[0053] Table 1 DMPP recovery loss rate of examples Table 2 DMPP recovery loss rate of comparative examples From the data in the table we can see that, under the same stirring time, the DMPP recovery rate of examples 1-4 is significantly higher than that of pure DMPP and comparative examples 1-5. Especially in the early stage of stirring (3 minutes and 5 minutes), the DMPP recovery rate of examples 1-4 all reaches 100%, while the recovery rate of pure DMPP is only 38.54% at 3 minutes and 27.99% at 5 minutes.

[0054] This shows that the high-temperature-resistant DMPP composite preparation prepared by the present application has better stability in a high-temperature environment (simulating 162°C of high-tower granulation), can effectively reduce the loss rate of DMPP, and improve the retention rate of DMPP in the fertilizer. By comparing the comparative examples and examples, it can be found that the high-molecular compound, the acidic substance and the sulfonated lignin all play an important role in the composite preparation, and the three synergize to improve the high-temperature stability of DMPP. The synergistic balance between the high-molecular compound, the acidic substance and the sulfonated lignin is broken in comparative examples 1-3 which change the composition of the substances, and the protection of DMPP is weakened, which leads to an increase in the loss rate of DMPP in a high-temperature environment. The amount of acidic substance in comparative example 4 is higher than that of the high-molecular compound, although the acidic substance fully foams to carry DMPP, but there is not enough high-molecular compound to absorb heat, which breaks the balance of the functions of the substances in the original formula, limits the wrapping and protection of DMPP by the high-molecular compound, and also leads to an increase in the loss rate of DMPP in a high-temperature environment compared with example 1. The stability of DMPP in a high-temperature environment of comparative example 5 of the prior art is far inferior to that of the composite preparations of examples 1-5, which shows that the raw materials and preparation method used in the present application have unique advantages in improving the high-temperature stability of DMPP. In our actual production, the preparation of the present application is added to the secondary tank of the high tower, and after stirring, granulation is immediately carried out, the DMPP stays in the high tower slurry for a very short time, generally not more than 5 minutes, and there is no loss of DMPP.

[0055] In order to further illustrate the nitrification inhibitor effect of the high-temperature-resistant DMPP composite preparation prepared by the present application, pot experiments and field experiments were carried out.

[0056] Pot experiment: Firstly, a fertilizer with a NPK ratio of 32-5-5 was prepared according to the laboratory simulation method; the composite preparation was prepared according to the method of example 1 of the present application, and the composite preparation was added to the fertilizer slurry for fertilizer granulation production, the addition amount was 1% of DMPP accounting for the total nitrogen amount (excluding nitrate nitrogen), and the residence time was 3 minutes, 5 minutes, 10 minutes, 15 minutes and 30 minutes, respectively, to obtain composite fertilizers A, B, C, D and E containing DMPP.

[0057] The pot experiment details are as follows: the experiment site is in the Stanley demonstration garden in Linshu County, Linyi City, Shandong Province, the experiment is carried out in the form of pot base fertilization, 5 kg of soil is placed in each pot, the fertilizers used in the treatment are mixed uniformly as base fertilizer, and 3.5 g of fertilizer is used in each pot. Then corn seeds are directly sown in the pot, 4 seeds per pot, and when the corn seedlings grow to about 5 cm, two seedlings with consistent growth are retained in the pot for later observation. Each treatment has 3 pots, 6 seedlings, and every two seedlings are used as a repetition, a total of 3 repetitions.

[0058] The agronomic experiment treatment is as follows: Table 3 test design Three batches of pot experiments are arranged, and the results of the first batch of pot experiments are as follows: Table 4 effect of different treatments on corn growth indexes As can be seen from the data in Table 4, during the early growth of corn, the base fertilizer obtained by adding the DMPP compound preparation of Example 1 of the present application has a positive promoting effect on the plant height, stem diameter and aboveground fresh weight indexes of corn. In terms of plant height, the addition of DMPP treatment has different degrees of synergistic effect compared with CK, among which the synergistic effect of T2 treatment is the best, which increases by 12.61% compared with the blank, followed by T1, with an increase of 9.47%, and the specific increase order is: T2>T1>T3>T4>T5>CK; In terms of stem diameter, the addition of DMPP treatment has different degrees of increase compared with CK, among which the effect of T2 treatment is the best, which increases by 10.65% compared with the blank, and the specific increase order is: T2>T1>T3>T4>T5>CK; In terms of aboveground fresh weight, the addition of DMPP has different degrees of synergistic effect compared with CK, among which the effect of T2 treatment is the best, which increases by 11.67% compared with the blank, followed by T1 treatment, with an increase of 8.97%, and the specific increase order is: T2>T1>T3>T4>T5>CK. It can be seen that the compound preparation of the present application is added to the fertilizer slurry for high tower granulation, and the DMPP loss in the obtained fertilizer is small, which can fully play the role of nitrification inhibition. The first batch of planting experiment effect diagram is shown in Figure 1 .

[0059] The results of the second batch of pot experiments are as follows: Table 5 effect of different treatments on corn growth indexes From the table data, it can be seen that T1-T5 fertilizers all show the effect of increasing efficiency, and each treatment is better than CK. In terms of plant height, each treatment is higher than CK, and the growth of T2 treatment is the highest, with an increase of 13.92%, followed by T1, with an increase of 13.01%. The specific performance is: T2>T1>T3>T4>T5>CK, which shows that DMPP can promote the growth of plant height, and it is speculated that it is due to the improvement of nitrogen utilization rate by DMPP; In terms of stem diameter, T1 and T2 are the best, which is 5.90% higher than CK, and the other three treatments are not obvious, and the specific performance is: T2=T1>T3>T4>T5>CK; From the aspect of SPAD, the chlorophyll of corn in five treatments is higher than that of CK, and the specific is T2>T3>T4>T5>T1>CK; In terms of fresh weight, the fresh weight of each treatment is higher than that of CK, among which T2 treatment is obviously higher than that of CK, and the yield increase effect is the best, and the specific performance is: T2>T1>T3>T4>T5>CK, and T5 treatment can still increase the yield by 7.25%. In addition to the fact that DMPP can prolong the effect of nitrogen fertilizer and improve the utilization rate of nitrogen, it is speculated that starch is hydrolyzed into monosaccharide and polysaccharide in high temperature and acidic environment, which becomes nutrients easy to be absorbed by crops, so as to achieve the effect of increasing yield. The effect diagram of the second batch planting experiment is shown in Figure 2 .

[0060] The results of the third batch of pot experiment are as follows: Table 6 Influence of different treatments on corn growth index The data shows that the addition of DMPP has the effect of increasing efficiency in the early and middle stages of corn, and each treatment has different degrees of efficiency than CK; In terms of plant height, the addition of DMPP treatment is higher than CK, among which T2 treatment is the best, which is 11.76% higher than blank, and T3 treatment is the second, with an increase of 9.57%. The specific effect order is: T2>T3>T4>T1>T5>CK; In terms of stem diameter, the addition of DMPP treatment is better than CK, among which T2 treatment is the best, which is 11.36% higher than blank, and T1 treatment is the second, with an increase of 10.35%. The specific effect order is: T2>T1>T3>T4>T5>CK; In terms of SPAD, the addition of DMPP treatment is higher than the chlorophyll content of CK, among which T2 treatment is the best, which is 14.92% higher than blank, and T1 treatment is the second, with an increase of 14.70%. The specific effect order is: T2>T1>T3>T4>T5>CK; In terms of fresh weight, the addition of DMPP treatment is higher than CK, among which T2 treatment is the best, which is 19.38% higher than blank, and T3 treatment is the second, with an increase of 18.87%. The specific effect order is: T2>T3>T1>T4>T5>CK; The effect diagram of the third batch of planting experiment is shown in Figure 3 .

[0061] Daejeon Experiment Experimental location: Wangshanzi Village, Jiaolong Town, Linshu County, Linyi City, Shandong Province. The specific plan is as follows: First, fertilizer preparation: A compound formulation was prepared according to the method in Example 1 of this invention. This formulation was added to a fertilizer slurry at approximately 160°C for fertilizer granulation. The addition amount was 1% of the total nitrogen (excluding nitrate nitrogen) by DMPP. The residence times were 3 minutes, 5 minutes, 10 minutes, 15 minutes, and 30 minutes, respectively, yielding compound fertilizers A, B, C, D, and E containing DMPP. The NPK ratio in the fertilizer was 32-5-5. The experimental design was as follows: each treatment group was repeated three times, and all measurement results were averaged.

[0062] Table 7 Experimental Design After maturity, five sampling points were randomly selected from each treatment group, and three maize plants were taken from each sampling point for performance measurements. These measurements included plant height, ear length, and ear diameter. Yield was determined by recording the actual yield of each treatment group. The field experiment results are as follows: Table 8. Effects of different treatments on maize indicators Data shows that adding DMPP to fertilizers has a positive synergistic effect on field corn, indicating that DMPP can improve nutrient utilization. Regarding ear length, all DMPP-treated ears were longer than the control, with T2 showing the largest increase (23.55%), followed by T1 with an increase of 18.92%. The order of increase was: T2 > T1 > T3 > T4 > T5 > CK. Regarding ear diameter, DMPP-treated ears showed some increase compared to the control, but the increase was not significant. The order of increase was: T2 > T1 > T3 > T4 > T5 > CK. Regarding yield per acre, all DMPP-treated ears showed some increase compared to the control, with T2 showing the largest increase (11.48%), followed by T3 with an increase of 10.89%. The order of increase was: T2 > T3 > T1 > T4 > T5 > CK. Based on the above data from pot and field experiments, adding DMPP can inhibit the activity of nitrifying bacteria in the soil, slow down the conversion of ammonium nitrogen to nitrate nitrogen, reduce nitrogen loss, and thus improve nitrogen use efficiency and crop yield.

[0063] Furthermore, the efficacy of the comparative formulation was verified using the methods described above. The composite preparation was prepared according to the method of Comparative Example 1-5 of the present application, and was added to the fertilizer slurry at a high temperature of about 160°C for fertilizer granulation production. The addition amount was 1% of DMPP based on the total nitrogen content (excluding nitrate nitrogen), and the residence time was 10 minutes, to obtain the DMPP-containing compound fertilizers a, b, c, d, and e. The NPK ratio in the fertilizer was 32-5-5. The CK and Example 1 refer to the above experimental data, and the experimental design is as follows: each treatment group was repeated three times, and the average value of all measured results was taken.

[0064] Table 9: Experimental design Table 10: Field experiment results are as follows: As can be seen from the data in Table 8, in the comparative example experiment, each treatment group still had a certain positive synergistic effect compared with the CK. In terms of ear length, the treatment groups adding the comparative example composite preparation were all longer than the CK, among which the increase of t4 was relatively large, being 11.28%, followed by t3, with an increase of 10.59%. The specific increase order was: t4>t3>t1>t2>t5>CK. This indicates that the comparative example composite preparation also promotes the growth of corn ear length to a certain extent.

[0065] In terms of ear thickness, each treatment group was increased compared with the CK, and the increase of t3 was relatively large, being 1.82%. The specific increase order was: t3>t4>t2>t1>t5>CK.

[0066] In terms of yield per mu, each treatment group was increased compared with the CK, and the specific increase order was: Example 1>t3>t4>t1>t2>t5>CK. By comparing Example 1 and the treatment groups of the comparative example, the comprehensive performance of Example 1 in ear length, ear thickness, and yield per mu was better, which further indicates that the DMPP composite preparation of Example 1 of the present application can better retain the effective components of DMPP during the fertilizer granulation process, thereby more effectively exerting its nitrification inhibition effect and improving the nutrient utilization rate of the fertilizer and the corn yield.

[0067] It should be noted that the above examples are only part of the preferred modes of implementing the present application, but not all. Obviously, based on the above examples of the present application, all other examples obtained by those of ordinary skill in the art without creative labor should fall within the scope of protection of the present application.

Claims

1. A high temperature resistant DMPP complex formulation, characterized in that, The raw materials include the following components by weight: 40-50 parts of a high molecular compound, 20-40 parts of an acidic substance, 0.5-2.5 parts of sulfonated lignin, and 25-40 parts of 3,4-dimethylpyrazole phosphate (DMPP).

2. The high temperature resistant DMPP complex formulation according to claim 1, wherein, The high molecular compound is starch and / or cellulose.

3. The high temperature resistant DMPP complex formulation according to claim 2, wherein, The cellulose is hydroxypropyl methyl cellulose.

4. The high temperature resistant DMPP complex formulation according to claim 1, wherein, The acidic substance is at least one of urea phosphate, urea sulfate, and citric acid.

5. The high temperature resistant DMPP complex formulation as claimed in claim 1, wherein, The amount of the high molecular compound is greater than that of the acidic substance.

6. A method for preparing the high-temperature resistant DMPP composite formulation according to any one of claims 1-5, characterized in that, The method includes the following steps: (a) mixing the acidic substance, the sulfonated lignin, the high molecular compound, and DMPP at room temperature for 10-20 minutes to form a premix; (b) then processing through a double-screw extruder at high temperature to obtain the composite preparation, wherein the discharge temperature of the double-screw extruder is 160°C, the rotation speed is 60 r / min, and the feeding frequency is 10 Hz.

7. The use of the high-temperature resistant DMPP compound preparation according to any one of claims 1-5 in high-temperature granulation of fertilizers, characterized in that, The preparation is directly added to a fertilizer slurry, and the product fertilizer is obtained after high-tower granulation.

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