A nitrogen fertilizer synergist composition and use thereof

Abstract

The application discloses a nitrogen fertilizer synergist composition and application thereof. The nitrogen fertilizer synergist composition is made of the following raw materials in mass parts: 5-40 parts of organic polymer material, 1-5 parts of polyolefin, 5-35 parts of crosslinking agent, 2-10 parts of inorganic acid, 50-100 parts of plant extract, 5-30 parts of inorganic salt, 5-30 parts of high molecular polymer, 5-30 parts of nitrogen synergist and 1000-3000 parts of water. The nitrogen fertilizer synergist composition can improve the utilization rate of nitrogen in soil or nitrogen fertilizer, i.e. can inhibit the conversion of ammonium nitrogen into nitrate nitrogen and reduce the loss of nitrogen fertilizer in the form of nitrate nitrogen. The nitrogen fertilizer synergist composition can effectively improve the stability of the nitrogen synergist in the production, storage, transportation and application of the fertilizer, realize the activity protection of the nitrogen synergist, improve the agricultural effect of the nitrogen synergist and reduce the greenhouse gas emission of the nitrogen fertilizer.

Description

TECHNICAL FIELD

[0001] The present application relates to a nitrogen fertilizer synergist composition and its application, belonging to the technical field of agricultural preparations. BACKGROUND

[0002] The application of nitrogen fertilizer synergists, such as nitrification inhibitors and urease inhibitors, as a strategy to address ecological problems caused by the use of chemical fertilizers and to increase crop yields, is becoming increasingly popular worldwide. Despite the potential of these inhibitors, they are degraded over time due to soil physicochemical and biological processes, thus reducing their expected environmental advantages.

[0003] Taking nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) as an example, its application rate must be ten times the standard application rate when the soil temperature exceeds 30°C. The efficiency of DMPP is affected by the content of hydrophobic organic matter in the soil that binds to DMPP. The urease inhibitor n-butyl thiophosphoric triamide (NBPT) is significantly affected by soil texture in its half-life, in addition, microbial degradation and the presence of low concentrations of heavy metal ions in the soil are also considered factors that affect the degradation of nitrogen synergists. Although the nitrogen fertilizer synergists applied to the soil should eventually decompose into products harmless to the environment, premature degradation during the crop growing season is highly undesirable, as this would result in the loss of inhibitory function and the failure to achieve the goal of reducing nitrogen loss.

[0004] In addition, since nitrogen fertilizers are usually added as additives to commercial fertilizer granules, nitrification inhibitors can be dissolved in the melt before urea granulation or granulation (US 5352265), or applied as a coating on the fertilizer granules (US 5698003). After these fertilizers are produced, they are transported from the factory to the field for use during the planting season. Therefore, over time, the nitrification inhibitors in these fertilizers are subjected to great environmental pressure, including fluctuations in temperature, humidity, and fertilizer pH.

[0005] The limited stability, volatility and significant difference in inhibition efficiency of nitrogen fertilizer synergist in different soils are the current focus. For example, WO 2018007426 proposes to use an organic solution to design a urease inhibitor composition to reduce the degradation of urease inhibitors; US2018265425 proposes to form a polyurea shell by interfacial polycondensation reaction between polyisocyanate and polyamine to realize the protection of nitrification inhibitor nitrapyrin. Although the systematic design and testing of coating systems help to isolate the nitrogen synergist from the external environment and reduce the influence of negative environment on the stability of the nitrogen synergist, the evaluation is mainly for the degradation rate of the nitrogen synergist itself, and there are few simulations of the addition link of the nitrogen synergist in the fertilizer chain and the soil degradation and efficacy of the nitrogen synergist. Because it is generally believed that the physical barrier of the nitrogen synergist through coating will affect its release rate, resulting in that the initial nitrogen synergist cannot achieve the expected dosage to affect the application effect. The improvement of the stability of the nitrogen synergist should ultimately be implemented in the actual agricultural effect, which has higher practical application value.

[0006] In summary, it is of great significance to develop a feasible technology for improving the stability of nitrogen synergist and improving agricultural efficiency, which can reduce the addition cost of nitrogen synergist, reduce nitrogen loss and realize low-carbon agriculture. SUMMARY

[0007] The purpose of the present application is to provide a nitrogen fertilizer synergist composition which can delay the occurrence time of N2O emission and reduce the total amount of N2O emission.

[0008] The nitrogen fertilizer synergist composition provided by the present application is made of the following mass parts of raw materials:

[0009] 5-40 parts of organic polymer material, 1-5 parts of polyolefin, 5-35 parts of crosslinking agent, 2-10 parts of inorganic acid, 50-100 parts of plant extract, 5-30 parts of inorganic salt, 5-30 parts of high molecular polymer, 5-30 parts of nitrogen synergist, 1000-3000 parts of water.

[0010] Preferably, the nitrogen synergist includes 3,4-dimethylpyrazole phosphate (DMPP), 3,4-dimethylpyrazole, n-butyl thiophosphoryl triamide, dicyandiamide, nitropyridine and hydrogen cyanide.

[0011] Preferably, the organic polymer material is sodium alginate;

[0012] The polyolefin is polyvinyl alcohol, polypropylene alcohol, polyethylene glycol or polylactic acid;

[0013] The crosslinking agent is calcium chloride or calcium lactate;

[0014] The inorganic acid is boric acid or phosphoric acid;

[0015] The plant extract is at least one of tannic acid, tea polyphenol and gallic acid, preferably tannic acid;

[0016] The inorganic salt is at least one of iron salt, copper salt, zinc salt and manganese salt, preferably ferric chloride;

[0017] The high molecular polymer is at least one of polyvinylpyrrolidone, polyethylene glycol, poly 4-styrene sulfonic acid sodium and polydimethyl diallyl ammonium chloride, preferably polyvinylpyrrolidone (molecular weight is 44000-54000).

[0018] The application provides a preparation method of the nitrogen fertilizer synergist composition, comprising the following steps:

[0019] S1, mixing a solution of polyolefin (obtained by stirring at 60-90 DEG C for 6-12 h) with a solution of organic high molecular material and nitrogen synergist to obtain a mixed solution I;

[0020] S2, pumping the mixed solution I into a syringe and dropping into a crosslinking solution to form gel microspheres;

[0021] The crosslinking solution is a mixed solution of crosslinking agent and inorganic acid;

[0022] S3, mixing a solution of plant extract, a solution of inorganic salt and a solution of high molecular polymer, adjusting pH to 5.7-6.7 (using sodium hydroxide), and standing to obtain a mixed solution II;

[0023] S4, mixing the gel microspheres with the mixed solution II, oscillating (0.5-1 h), sieving (sieveing the mixed solution II not wrapped), and freeze-drying to obtain the product.

[0024] In the above preparation method, in step S2, the residence time of the gel microspheres in the crosslinking solution is not more than 30 min.

[0025] In the above preparation method, in step S3, the pH is adjusted after stirring at 20-40 DEG C for 1-3 h.

[0026] The nitrogen fertilizer synergist composition provided by the application can be used for preparing nitrogen fertilizer.

[0027] The nitrogen fertilizer can be solid nitrogen fertilizer or liquid nitrogen fertilizer, including but not limited to compound fertilizer, solid water-soluble fertilizer, liquid fertilizer and the like.

[0028] The nitrogen fertilizer synergist composition provided by the application can improve the utilization rate of nitrogen in soil or nitrogen fertilizer, i.e. can inhibit the conversion of ammonium nitrogen into nitrate nitrogen and reduce the loss of nitrogen fertilizer in the form of nitrate nitrogen.

[0029] When the nitrogen fertilizer synergist composition is applied, it can be added in the production process of the nitrogen fertilizer or directly applied in the field by compounding with the nitrogen fertilizer.

[0030] When added in the production process of the nitrogen fertilizer, it is preferably added in the drum granulation or tower granulation of the nitrogen fertilizer;

[0031] The temperature during the drum granulation or the tower granulation is not more than 150℃; when more than 180℃, the retention time of the nitrogen fertilizer synergist composition is ≤5min;

[0032] When directly used in the field, the nitrogen fertilizer synergist composition is directly applied after compounding with the nitrogen fertilizer;

[0033] Preferably, when the nitrogen fertilizer is a granular fertilizer, the fertilizer is applied within 1-10 days after compounding;

[0034] When the nitrogen fertilizer is liquid nitrogen fertilizer such as urea ammonium nitrate, liquid ammonia, etc., the fertilizer is applied within 1-10 days after compounding;

[0035] When the nitrogen fertilizer is liquid nitrogen fertilizer such as compound fertilizer containing multiple nutrient elements, bio-organic fertilizer, etc., the fertilizer is applied within 1-3 days after compounding.

[0036] The present application has the following beneficial technical effects:

[0037] The nitrogen fertilizer synergist composition of the present application can effectively improve the stability of the nitrogen synergist in the production, storage, transportation and application of the fertilizer, realize the activity protection of the nitrogen synergist, improve the agricultural effect of the nitrogen synergist, and reduce the greenhouse gas emission of the nitrogen fertilizer. DETAILED DESCRIPTION

[0038] The experimental methods used in the following examples are conventional methods unless otherwise specified.

[0039] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0040] Example 1, preparation of the nitrogen fertilizer synergist composition

[0041] The mass parts of each raw material are as follows:

[0042] 6.75 parts of sodium alginate, 1.5 parts of polyvinyl alcohol, 10 parts of calcium chloride, 5 parts of boric acid, 50 parts of plant extract tannic acid, 13 parts of inorganic salt ferric chloride, 6 parts of polyvinylpyrrolidone, 5 parts of nitrogen synergist DMPP, and 2000 parts of water.

[0043] The preparation steps are as follows:

[0044] 1) Dissolve polyvinyl alcohol in water, stir at 80℃ for 10h, and prepare a polyvinyl alcohol solution (solution A1)

[0045] 2) Dissolve sodium alginate, nitrogen efficiency enhancer DMPP in water to prepare an aqueous solution (solution A2)

[0046] 3) Mix solution A1 and solution A2 to prepare a mixed solution (solution B)

[0047] 4) Dissolve a cross-linking agent (calcium chloride) and an acid (boric acid) in water to prepare a cross-linking solution (solution C)

[0048] 5) Pump solution B into a syringe and drop into solution C to form gel microspheres, and filter; wherein the residence time of the gel microspheres in solution C is not more than 30 min.

[0049] 6) Dissolve a plant extract (tannic acid) in water to prepare an aqueous solution (solution D1)

[0050] 7) Dissolve an inorganic salt (ferric chloride) in water to prepare an aqueous solution (solution D2)

[0051] 8) Dissolve a high molecular polymer (polyvinylpyrrolidone) in water (solution D3)

[0052] 9) Mix solution D1, D2 and D3 according to a mass ratio of 15:1:4, stir at 20-40℃ for 2-3h, adjust the pH to 6.4 with sodium hydroxide solution, and stand for 1-2h to prepare solution E;

[0053] 10) Mix the gel microspheres with solution E and shake for 0.5-1h, filter and screen the un-wrapped solution E, and freeze-dry to obtain a composition capable of improving the effect of nitrogen efficiency enhancer.

[0054] Application Example 1: Evaluation of the composition of the present application capable of improving the effect of nitrogen efficiency enhancer to improve the stability of nitrogen efficiency enhancer in the production process of fertilizer

[0055] The composition prepared in Example 1 is used as an example; and untreated DMPP is used as a control. The degradation rate of DMPP under different conditions is determined by simulating the temperature (70℃, 125℃, 200℃) and heating time (5min, 15min, 30min) faced in the production of fertilizer.

[0056] The content of DMPP is determined by high performance liquid chromatography (HPLC, 1260Infinity II, USA). The chromatographic column is ZORBAX C18 250×4.6, 30℃. Phosphoric acid solution (0.01M sodium dihydrogen phosphate) is used as mobile phase A, and acetonitrile is used as mobile phase B, and the ratio of A to B is 7:3. The flow rate is 1ml / min, and the temperature is 30℃. The injection volume is 20μ. The detection wavelength is 224nm.

[0057]

[0058] wherein DMPP represents the degradation rate (%) of DMPP; C T and C T0 respectively DMPP content in different fertilizer treatments after heating and before heating.

[0059] Table 1 Degradation rate of DMPP under different temperature treatments

[0060]

[0061] The results of Table 1 show that the use of the composition of the present application significantly reduces the degradation rate of DMPP at 70°C, 125°C, and significantly reduces the degradation rate of DMPP at 200°C for 5 min heating time. The higher the temperature and the longer the heating time, the lower the protective effect of the composition on the nitrogen efficiency agent. The prior art can meet the temperature environment of most fertilizer production processes below 125°C. Since the composition of the present application improves the stability of the nitrogen efficiency agent mainly by maintaining the integrity of the calcium alginate-polyphenol hybrid material, it is recommended that the application temperature should not exceed the tolerance temperature of the material, 150°C, and should not be applied to extrusion granulation.

[0062] Example 2, Evaluation of the composition of the present application with improved nitrogen efficiency agent effect to improve the stability of the nitrogen efficiency agent during agricultural application

[0063] The composition prepared in Example 1 is used as the example; untreated DMPP is used as the control example.

[0064] Different treatments are added to 10 g of soil, respectively, and static soil culture is carried out under the conditions of 60% soil pore water content, 25°C temperature, DMPP in the soil is extracted at the specified time, and the degradation rate of DMPP in the soil is determined. Two kinds of soil are selected, one is a meadow soil taken from the Quzhou Experimental Station of China Agricultural University, and the other is a black soil taken from the Pishu Science and Technology Courtyard in Jilin, with soil pH of 7.9 and 5.6, respectively. The DMPP content in the soil is determined at 3, 7, 14, and 21 days of culture, respectively.

[0065] The content of DMPP is determined in accordance with the test, and the residual rate (%) of DMPP in the soil is used to represent the effect of the composition of the present application on the improvement of the degradation rate of DMPP.

[0066] Table 2 Residual rate (%) of DMPP in different soils

[0067]

[0068] The results of Table 2 show that the composition of the present application significantly improves the residual rate of DMPP in two different pH soils, indicating that the effect of soil chemistry and biological processes on the degradation ability of DMPP is weakened by the composition of the present application. In order to further analyze the effect of this weakened degradation ability of DMPP on the actual agricultural application, the agricultural effect of the nitrogen efficiency agent under this technical condition was determined by static soil culture test, and the treatments were as follows:

[0069] The composition prepared in Example 1 was used as the example; untreated DMPP was used with nitrogen fertilizer as Comparative Example 1; only nitrogen fertilizer was added without any nitrogen efficiency agent as Comparative Example 2.

[0070] The nitrogen fertilizer was added in Quzhou soil at a fertilizer dosage of 100 mg N / kg soil, and the comparative example and the example were added respectively, and the content of DMPP in the comparative example and the example was controlled to be consistent. The cumulative emission of N2O in the soil.

[0071] Among them, the amount of the nitrogen efficiency agent composition of the present application used in this example is 0.1% of the weight of the soil used in this example.

[0072] Table 3 Total amount of N2O emission in soil of different treatments (μg N kg -1 )

[0073] Example Comparative Example 1 Comparative Example 2 3 days 0 4.6±1.5 79.3±25.7 7 days 0 17.5±0.5 367±73.2 15 days 5.3±1.1 40.4±2.5 392.7±97.8 40 days 40.5±4.6 53.1±1.7 392.7±97.8

[0074] Since the representative substance DMPP is a nitrification inhibitor, it is mainly used in agriculture to inhibit the nitrification process and reduce the loss of nitrogen fertilizer as N2O, therefore, N2O is taken as the target index to determine whether the technology can enhance the agricultural effect of the nitrogen efficiency agent, and the results show that compared with the traditional formula, the composition of the present application delays the appearance time of N2O emission and reduces the total amount of N2O emission.

Claims

1.A nitrogen fertilizer synergist composition made of the following raw materials in mass parts: 5-40 parts of an organic polymer material, 1-5 parts of a polyolefin, 5-35 parts of a crosslinking agent, 2-10 parts of an inorganic acid, 50-100 parts of a plant extract, 5-30 parts of an inorganic salt, 5-30 parts of a high molecular polymer, 5-30 parts of a nitrogen synergist, and 1000-3000 parts of water; wherein the nitrogen synergist comprises 3, 4-dimethylpyrazole phosphate, 3, 4-dimethylpyrazole, n-butyl thiophosphoric amide, dicyandiamide, nitropyridine, and hydroquinone; the organic polymer material is sodium alginate; the polyolefin is polyvinyl alcohol or polypropylene alcohol; the crosslinking agent is calcium chloride or calcium lactate; the inorganic acid is boric acid or phosphoric acid; the plant extract is at least one of tannic acid, tea polyphenol, and gallic acid; the inorganic salt is at least one of iron salt, copper salt, zinc salt, and manganese salt; and the high molecular polymer is at least one of polyvinylpyrrolidone, polyethylene glycol, poly (4-styrene sulfonic acid) sodium, and polydimethyl diallyl ammonium chloride. 2.The preparation method of the nitrogen fertilizer synergist composition of claim 1, comprising the following steps: S1, mixing a solution of polyolefin with a solution of organic polymer material and nitrogen synergist to obtain a mixed solution I; S2, pumping the mixed solution I into a syringe and dropping into a crosslinking solution to form gel microspheres; wherein the crosslinking solution is a mixed solution of crosslinking agent and inorganic acid; S3, mixing a solution of plant extract, a solution of inorganic salt, and a solution of high molecular polymer, adjusting pH to 5.7-6.7, and standing to obtain a mixed solution II; and S4, mixing the gel microspheres with the mixed solution II, and then oscillating, sieving, and freeze-drying to obtain the nitrogen fertilizer synergist composition. 3.The nitrogen fertilizer synergist composition of claim 1, wherein the residence time of the gel microspheres in the crosslinking solution in step S2 is not more than 30 min. 4.The nitrogen fertilizer synergist composition of claim 1, wherein the pH is adjusted after stirring at 20-40℃ for 1-3 h in step S3. 5.The nitrogen fertilizer synergist composition of claim 1, which is used in any one of the following: 1) preparation of nitrogen fertilizer; 2) improvement of nitrogen utilization rate in soil or nitrogen fertilizer; and 3) plant cultivation. 6.The nitrogen fertilizer synergist composition of claim 1, which is added in drum granulation or high tower granulation of the nitrogen fertilizer. 7.The nitrogen fertilizer synergist composition of claim 1, wherein the temperature in the drum granulation or the high tower granulation is not more than 150℃, and the residence time of the nitrogen fertilizer synergist composition is ≤5 min when the temperature exceeds 180℃. 8.The nitrogen fertilizer synergist composition of claim 1, which is directly applied after being mixed with the nitrogen fertilizer. 9.The nitrogen fertilizer of claim 8, wherein the nitrogen fertilizer is granular fertilizer, and the nitrogen fertilizer synergist composition is applied within 1-10 days after mixing. ​ ​ ​ ​ ​ ​ ​ 3. The method of claim 2, wherein: ​ 4. The production method according to claim 2 or 3, characterized by: ​ ​ 6. Use according to claim 5, characterized in that: ​ ​ 7. Use according to claim 6, characterized in that: ​ ​ When the nitrogen fertilizer is liquid nitrogen fertilizer A, apply the fertilizer within 1 to 10 days after mixing; when the nitrogen fertilizer is liquid nitrogen fertilizer B, apply the fertilizer within 1 to 3 days after mixing. The liquid nitrogen fertilizer A is urea ammonium nitrate and liquid ammonia; The liquid nitrogen fertilizer B is a compound fertilizer and bio-organic fertilizer containing multiple nutrients.

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