Fertilizer synergist for reducing nutrient loss and inhibiting nitrification and application thereof

Abstract

The invention provides a fertilizer synergist for reducing nutrient loss and inhibiting nitrification and application of the fertilizer synergist. The fertilizer synergist is prepared from the following components in percentage by mass: 95 to 98 percent of carboxyl cross-linked modified montmorillonite, 0.05 to 0.1 percent of mannan oligosaccharide, 0.1 to 0.5 percent of mannan, 1 to 3 percent of polyaspartate and 0.5 to 2 percent of a nitrification inhibiting aid. According to the fertilizer synergist capable of reducing nutrient loss and inhibiting nitrification and the application of the fertilizer synergist, the fertilizer synergist serves as a plant nutrient loss control synergist and a nitrification inhibitor and can activate a crop stress resistance signal source, promote and induce synthesis of endogenous auxin in plants, root and growth, activate phosphorus and dissolve potassium, reduce nitrogen loss and improve the yield of the plants. The fertilizer utilization rate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, and particularly relates to a fertilizer synergist for reducing nutrient loss and inhibiting nitrification and its application. Background Art

[0002] With the deepening of the dependence on fertilizers in modern agriculture, the problems of nitrogen loss and environmental pollution caused by excessive application of nitrogen fertilizers are becoming increasingly severe. Nitrification is one of the core processes of the soil nitrogen cycle, and the nitrate nitrogen produced by it is easily caused by leaching and denitrification to cause eutrophication of water bodies and greenhouse gas emissions. About 50% of the nitrogen fertilizers globally are lost due to nitrification, which severely restricts the sustainable development of agriculture. Traditional chemical nitrification inhibitors (such as DMPP, dicyandiamide), although they can delay the nitrification process by inhibiting the activity of ammonia-oxidizing microorganisms, their effects are significantly affected by the physical and chemical properties of the soil (such as conductivity, organic carbon content), and the inhibitory effect on ammonia-oxidizing archaea (AOA) is limited. Long-term use may also cause microbial resistance. In addition, a single nitrification-inhibiting synergist is difficult to synchronously solve the problems of nitrogen volatilization and the fixed loss of nutrients such as phosphorus and potassium. There is an urgent need to develop a composite synergist with multi-channel loss control functions. Summary of the Invention

[0003] Based on the technical problems existing in the background art, the present invention proposes a fertilizer synergist for reducing nutrient loss and inhibiting nitrification and its application. The fertilizer synergist, as a plant nutrient loss control synergist and nitrification inhibitor, can activate the stress resistance signal source of crops, promote and induce the synthesis of endogenous auxin in plants, promote root growth, activate phosphorus and release potassium, reduce nitrogen loss, and improve fertilizer utilization rate.

[0004] The present invention proposes a fertilizer synergist for reducing nutrient loss and inhibiting nitrification, which comprises, by mass percentage: 95-98% of carboxyl cross-linked modified montmorillonite, 0.05-0.1% of mannan oligosaccharide, 0.1-0.5% of mannan, 1-3% of polyaspartate, and 0.5-2% of nitrification inhibition assistant.

[0005] Preferably, the carboxyl cross-linked modified montmorillonite is obtained by acidifying montmorillonite, coupling and modifying it with an alkenyl silane coupling agent, and then carrying out a copolymerization reaction with methylene succinic acid.

[0006] In the present invention, montmorillonite belongs to silicate minerals. First, montmorillonite is acidified to dissolve the interlayer metal ions (such as , etc.) to increase the specific surface area and acidic sites, endowing montmorillonite itself with relatively strong cation exchange capacity. Then, an alkenyl silane coupling agent is used for the coupling reaction with montmorillonite, enabling the alkenyl silane coupling agent to react with the surface hydroxyl groups of montmorillonite to form covalent bonds, grafting alkenyl organic groups on the surface of montmorillonite. Thereafter, methylene succinic acid is added, and the alkenyl organic groups and methylene succinic acid carry out copolymerization under the condition of an initiator, thereby forming a carboxyl cross-linked polymer between montmorillonite particles. The carboxyl cross-linked polymer is grafted between montmorillonite particles through covalent bonds, expanding the montmorillonite layer spacing and forming a large number of carboxyl group clusters on the surface of montmorillonite. On the one hand, the adsorption capacity for pollutants and the water absorption capacity of montmorillonite itself are improved, and the water retention effect is enhanced; on the other hand, it promotes the formation of soil aggregate structure through colloid and hydrogen bond actions, and can effectively inhibit the loss of water and nutrients in soil and water. Thereafter, mannan oligosaccharide and mannan are added in sequence as crop nutrient supplements to improve fertilizer efficiency, polyaspartate is added to chelate heavy metal ions to reduce their influence on the crop growth process, and a nitrification inhibitor can effectively inhibit the nitrification of soil, and finally a fertilizer synergist with two functions of controlling fertilizer nutrient loss and inhibiting nitrification is prepared.

[0007] Preferably, the alkenyl silane coupling agent is at least one of vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-methacryloxypropyltriisopropoxysilane or 3-acryloxypropyltrimethoxysilane; Preferably, the mass ratio of the montmorillonite to the alkenyl silane coupling agent is 1:0.05 - 0.1.

[0008] Preferably, the particle size of the montmorillonite is 10 - 200 μm; Preferably, the mass ratio of the montmorillonite to the methylene succinic acid is 1:0.1 - 0.2.

[0009] Preferably, the copolymerization reaction is carried out under the condition of an initiator; Preferably, the initiator is one of potassium persulfate, sodium persulfate or ammonium persulfate.

[0010] Preferably, the copolymerization reaction further includes adding a tertiary amino acrylate; Preferably, the tertiary amino acrylate is dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate.

[0011] In the present invention, after the tertiary amine group acrylate participates in the copolymerization reaction, the carboxyl cross-linked polymer formed between montmorillonite particles contains tertiary amine groups. A reaction can occur between the original carboxyl groups and the tertiary amine groups to form quaternary ammonium salts. The cationic characteristics of the quaternary ammonium salts can not only enhance the water absorption capacity of montmorillonite, but also adsorb nitrate ions in the soil, etc., further fixing the nutrient elements and nutrients required by plants in the soil to reduce the loss of fertilizer nutrients. At the same time, it can also promote plant growth.

[0012] Preferably, the polyaspartate is at least one of zinc polyaspartate, sodium polyaspartate, potassium polyaspartate or calcium polyaspartate.

[0013] Preferably, the nitrification inhibitor adjuvant is 3,4-dimethylpyrazole phosphate.

[0014] The present invention also provides an application of the above fertilizer synergist in the preparation of fertilizers.

[0015] Preferably, the fertilizer synergist is added to the fertilizer in a proportion of 1-10 wt%.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The fertilizer synergist of the present invention, by containing components such as carboxyl cross-linked modified montmorillonite, can improve the soil structure, increase the soil porosity and air permeability, improve the soil water retention capacity, and can also significantly improve the utilization rate of nutrients such as nitrogen, phosphorus and potassium in fertilizers, reduce the loss and waste of nutrients. In addition, under the combined compounding of components such as mannan oligosaccharide and mannan, it has a synergistic effect, which can increase the absorption of soil nutrients by crops, improve the fertilizer utilization rate, and at the same time delay the conversion of ammonium nitrogen to nitrate nitrogen, realize nitrification inhibition, and ultimately promote the improvement of crop yield and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the SEM diagram of the carboxyl cross-linked modified montmorillonite described in Example 1 of the present invention; Figure 2 It is the structural schematic diagram of the sand column leaching device described in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, the technical solutions of the present invention will be described in detail through specific examples. However, it should be clearly stated that these examples are for illustrative purposes only and are not construed as limiting the scope of the present invention.

[0019] Example 1

[0020] A fertilizer synergist for reducing nutrient loss and inhibiting nitrification, comprising by mass percentage: 96.5% of carboxyl cross-linked modified montmorillonite, 0.08% of mannan oligosaccharide, 0.32% of mannan, 1.5% of zinc polyaspartate, and 1.6% of 3,4-dimethylpyrazole phosphate; The carboxyl cross-linked modified montmorillonite is prepared by the following method: Montmorillonite (calcium-based montmorillonite, 200 mesh) is added to a 1 mol / L nitric acid solution and ultrasonically oscillated to disperse evenly. The content of montmorillonite in the nitric acid solution is 15 wt%. After stirring and reacting at 80 °C for 6 h, an acidified montmorillonite suspension is obtained. After filtration and washing with pure water until neutral, acidified montmorillonite is obtained; The obtained acidified montmorillonite is added to pure water and ultrasonically oscillated to disperse evenly. Vinyltrimethoxysilane is added, and the dosage of vinyltrimethoxysilane is 7 wt% of montmorillonite. After ultrasonically oscillating and reacting at 60 °C for 6 h, suction filtration, washing, and drying are carried out to obtain alkenyl-modified montmorillonite; The obtained alkenyl-modified montmorillonite is added to pure water again. After stirring and dispersing evenly, methylene succinic acid is added and dissolved completely. The dosage of methylene succinic acid is 15 wt% of montmorillonite. Then potassium persulfate is added, and the dosage of potassium persulfate is 0.5 wt% of montmorillonite. After stirring and reacting at 50 °C under nitrogen protection for 2 h, suction filtration, washing, and drying are carried out to obtain the carboxyl cross-linked modified montmorillonite.

[0021] The above-mentioned fertilizer synergist can be prepared by stirring and mixing the components evenly.

[0022] In this example, the SEM image of the carboxyl cross-linked modified montmorillonite is as Figure 1 shown. It can be seen from Figure 1 that a three-dimensional polymer network (green circle) is formed between montmorillonite particles, and at the same time, there are also many relatively large pores (yellow circle). Thus, it can be intuitively seen that the modified montmorillonite has a structural basis for achieving the effects of water and fertilizer retention.

[0023] Example 2

[0024] A fertilizer synergist for reducing nutrient loss and inhibiting nitrification, comprising by mass percentage: 95% of carboxyl cross-linked modified montmorillonite, 0.1% of mannan oligosaccharide, 0.1% of mannan, 3.8% of zinc polyaspartate, and 1% of 3,4-dimethylpyrazole phosphate; The carboxyl cross-linked modified montmorillonite is prepared by the method described in Example 1.

[0025] The above-mentioned fertilizer synergist can be prepared by stirring and mixing the components evenly.

[0026] Example 3

[0027] A fertilizer synergist for reducing nutrient loss and inhibiting nitrification, comprising by mass percentage: 98% of carboxyl cross-linked modified montmorillonite, 0.05% of mannan oligosaccharide, 0.45% of mannan, 1% of zinc polyaspartate, and 0.5% of 3,4-dimethylpyrazole phosphate; The carboxyl cross-linked modified montmorillonite is prepared by the method described in Example 1.

[0028] The fertilizer synergist can be prepared by uniformly stirring and mixing the components of the above fertilizer synergist.

[0029] Example 4

[0030] A fertilizer synergist for reducing nutrient loss and inhibiting nitrification, comprising by mass percentage: 96.5% of carboxyl cross-linked modified montmorillonite, 0.08% of mannan oligosaccharide, 0.32% of mannan, 1.5% of zinc polyaspartate, and 1.6% of 3,4-dimethylpyrazole phosphate; The carboxyl cross-linked modified montmorillonite is prepared by the following method: Montmorillonite (calcium-based montmorillonite, 200 mesh) is added to a 1 mol / L nitric acid solution and ultrasonically dispersed evenly. The content of montmorillonite in the nitric acid solution is 15 wt%. After stirring and reacting at 80 °C for 6 h, an acidified montmorillonite suspension is obtained. After filtration and washing with pure water until neutral, acidified montmorillonite is obtained; The obtained acidified montmorillonite is added to pure water and ultrasonically dispersed evenly. Vinyltrimethoxysilane is added, and the dosage of vinyltrimethoxysilane is 7 wt% of montmorillonite. After ultrasonically reacting at 60 °C for 6 h, suction filtration, washing, and drying are carried out to obtain alkenyl-modified montmorillonite; The obtained alkenyl-modified montmorillonite is added to pure water again, stirred and dispersed evenly, then methylene succinic acid is added and dissolved completely. The dosage of methylene succinic acid is 15 wt% of montmorillonite. Then dimethylaminoethyl acrylate is added, and the dosage of dimethylaminoethyl acrylate is 3 wt% of montmorillonite. Then potassium persulfate is added, and the dosage of potassium persulfate is 0.5 wt% of montmorillonite. After stirring and reacting at 50 °C under nitrogen protection for 2 h, suction filtration, washing, and drying are carried out to obtain the carboxyl cross-linked modified montmorillonite.

[0031] The fertilizer synergist can be prepared by uniformly stirring and mixing the components of the above fertilizer synergist.

[0032] Comparative Example 1 A fertilizer synergist, comprising by mass percentage: 96.5% of montmorillonite (calcium-based montmorillonite, 200 mesh), 0.08% of mannan oligosaccharide, 0.32% of mannan, 1.5% of zinc polyaspartate, and 1.6% of 3,4-dimethylpyrazole phosphate.

[0033] The fertilizer synergist can be prepared by uniformly stirring and mixing the components of the above fertilizer synergist.

[0034] Comparative Example 2 A fertilizer synergist, by mass percentage, includes: 96.5% of carboxyl polymer modified montmorillonite, 0.08% of mannan oligosaccharide, 0.32% of mannan, 1.5% of zinc polyaspartate, and 1.6% of 3,4-dimethylpyrazole phosphate; The carboxyl polymer modified montmorillonite is prepared by the following method: Add montmorillonite (calcium-based montmorillonite, 200 mesh) into 1 mol / L nitric acid solution and disperse it evenly by ultrasonic oscillation. The content of montmorillonite in the nitric acid solution is 15 wt%. After stirring and reacting at 80 °C for 6 h, an acidified montmorillonite suspension is obtained. After filtration and washing with pure water until neutral, acidified montmorillonite is obtained; Add methylene succinic acid into pure water, stir and disperse it evenly, then add potassium persulfate. The dosage of potassium persulfate is 3.5% of methylene succinic acid. After stirring and reacting at 50 °C under nitrogen protection for 2 h, concentrate and dry to obtain carboxyl polymer; Add the acidified montmorillonite and carboxyl polymer into pure water. The dosage of carboxyl polymer is 15 wt% of montmorillonite. After stirring and dispersing evenly at 50 °C, place it in an oven to dry, and the carboxyl polymer modified montmorillonite is obtained.

[0035] Performance test: 1. Weigh a certain amount of the unmodified montmorillonite described in Comparative Example 1 and the modified montmorillonite described in Example 1 and put them into a certain amount of pure water, and control the concentrations to be 1%, 2%, 3%, 4%, and 5% (w / w) respectively. Then stir with a dispersion disk for 10 min, and let it stand and swell for 5 min after stirring. Use a viscometer for testing, and the test results are as follows:

[0036] As can be seen from Table 1 above, compared with the unmodified montmorillonite in Comparative Example 1, the viscosity of the modified montmorillonite in Example 1 increases significantly, that is, the water absorption capacity increases. It can be seen that adding the modified montmorillonite described in Example 1 to the fertilizer can effectively improve the water retention effect.

[0037] Montmorillonite itself is a layered silicate mineral, formed by the alternating arrangement of silicon-oxygen tetrahedrons and aluminum-oxygen octahedrons to form a two-dimensional sheet structure. The layer spacing (interlayer domain) has the ability to adsorb water molecules and polar molecules. When encountering water, the layer spacing can expand to more than ten times the original volume, forming a gel-like substance; the modified montmorillonite material described in Example 1 improves the water adsorption capacity, so the formed gel-like substance has a greater viscosity.

[0038] 2. Conduct a sand column leaching experiment on the fertilizer synergist of Example 1 and Comparative Example 1 according to 50 g of potassium chloride + 5 g of fertilizer synergist. At the same time, set 50 g of pure potassium chloride without adding fertilizer synergist as the control group. Simulate natural rainfall conditions through sand column leaching, compare the difference in the loss of potassium oxide between the sample group added with fertilizer synergist and the control group without addition, and calculate the loss control rate.

[0039] The specific method is as follows: (1) Reagents and materials: Potassium chloride (analytical grade), the synergist described in the examples and Comparative Example 1 (reserved after drying); River sand is sieved to 0.125 - 0.425 mm, washed, dried, and reserved; Balance (±0.1 g), analytical balance (±0.0002 g), graduated cylinder (250 mL), volumetric flask (250 mL); Flame photometer or sodium tetraphenylborate gravimetric method (according to GB / T 6549); The sand column leaching device is self-made and consists of a glass column with a diameter of 4.5 cm and a length of 30 cm. A cock is provided at the lower end of the glass column. See Figure 2 .

[0040] (2) Sample preparation: Control group: 50 g of potassium chloride is ground into powder; Sample group 1: 50 g of potassium chloride + 5 g of the fertilizer synergist in Comparative Example 1, and they are mixed by high-speed crushing for 20 seconds; Sample group 2: 50 g of potassium chloride + 5 g of the fertilizer synergist in Example 1, and they are mixed by high-speed crushing for 20 seconds. Control group: 1.000 g (accurate to 0.0002 g); Sample group 1: 1.100 g (accurate to 0.0002 g); Sample group 2: 1.100 g (accurate to 0.0002 g), with 3 parallel samples in each group.

[0041] (3) Sand column filling: The bottom of the leaching column is filled with absorbent cotton and compacted; 200 g of river sand (about 10 cm high) is loaded, and it is compacted by tapping 10 times; After adding 100 mL of water to soak and then draining, a round pit with a diameter of 12 mm and a depth of 20 mm is formed in the center of the sand column with a punch.

[0042] (4) Sample loading: The control group / sample group specimens are added into the round pit through a diversion tube, and 1 mL of water is used to wash the residue in the diversion tube and cover a 60 g river sand layer (about 3 cm) to prevent water disturbance.

[0043] (5) Leaching process: Add 100 mL of water to soak for 0.5 h; Open the valve and collect the leaching solution into a 250 mL volumetric flask for constant volume.

[0044] (6) Potassium oxide determination: Control group: Take 10 mL of the leaching solution and determine the potassium oxide content according to GB / T 6549; Sample group 1: Take 25 mL of the leaching solution and determine it in the same way; Sample group 2: Take 25 mL of the leaching solution and determine it in the same way.

[0045] The test results and data processing are as follows:

[0046] The formula for the controlled loss rate:

[0047] X1: The average potassium oxide content in the control group (%); X2: The average potassium oxide content in the sample group (%). Average potassium oxide content in the control group: X1 = 52.4%; Average potassium oxide content in sample group 1: X2 = 35.6%; Average potassium oxide content in sample group 2: X2 = 31.6%; Average loss control rate in sample group 1: W1 = 32.4%; Average loss control rate in sample group 2: W1 = 39.7%; The loss control rates of the three parallel samples in sample group 1 are 32.1%, 33.3%, and 31.8% respectively, and the loss control rates of the three parallel samples in sample group 2 are 32.4%, 30.8%, and 31.6% respectively. The absolute difference between the two groups is ≤2.5% (meeting the requirement that the parallel difference ≤6%). As can be seen from Table 1 above, the measured results of the loss control rate of the fertilizer synergist described in Comparative Example 1 under unmodified conditions are 31.8% - 33.3%, with an average value of 32.4%. The loss control rates of all parallel samples are ≥30%, and the data repeatability is good. Therefore, the loss control performance of the formula synergist of the present invention is qualified; while the measured results of the loss control rate of the fertilizer synergist described in Example 1 are 38.2% - 41.2%, with an average value of 39.7%, and the loss control performance is more excellent. It can be seen that the modified montmorillonite significantly improves the loss control effect of the overall formula. It can form a cross-linked sol state, enhance the binding ability with the soil, avoid leaching loss, and improve the fixation effect on fertilizers.

[0048] 3. Conduct a soil culture experiment on the fertilizer synergists of Example 1 and Comparative Example 1 according to 99.4 g of ammonium chloride + 0.6 g of fertilizer synergist. At the same time, set a pure 99.4 g of ammonium chloride without adding fertilizer synergist as the control group. Sample after culturing for several days respectively, measure the ammonium nitrogen and nitrate nitrogen contents in the soil, and calculate the soil nitrification inhibition rate.

[0049] (1) Reagents and materials: Ammonium chloride (analytical pure), the synergist of the present invention, 2 mol / L KCl solution, nitrification inhibitor standard product (optional); Ammonium chloride (analytical pure), the synergist of the present invention, 2 mol / L KCl solution, nitrification inhibitor standard product (optional); Fresh farmland soil (pH 6.5 - 7.5, organic matter ≥1.5%, passed through a 2 mm sieve, pre-cultured for 7 days to restore microbial activity).

[0050] (2) Sample preparation: Control group: 99.4 g of ammonium chloride (simulating conventional fertilizer); Sample group 1: 99.4 g of ammonium chloride + 0.6 g of the fertilizer synergist of Comparative Example 1 (mixed according to the standard ratio); Sample group 2: 99.4 g of ammonium chloride + 0.6 g of the fertilizer synergist of Example 1 (mixed according to the standard ratio); Set 3 parallel samples for each group and mix them thoroughly with the soil.

[0051] (3) Soil treatment: Weigh 200 g of pre-cultured soil (dry basis) into a culture bottle; Add the test sample (control group / sample group) and mix it evenly with the soil, adjust the soil water content to 60% of the field water holding capacity; Seal the culture bottle and culture it at 25°C in the dark for 28 days.

[0052] (4)Sampling and determination: Time points: at the start of cultivation (0 days), 7 days, 14 days, 28 days; Sampling operation: Each time, 10 g of soil is taken, added with 50 mL of 2 mol / L KCl solution, shaken for 30 min, centrifuged and filtered, and the supernatant is taken; Ammonium nitrogen (NH4 + -N): Indophenol blue colorimetric method (GB / T 3597); Nitrate nitrogen (NO3 - -N): Ultraviolet spectrophotometry (GB / T 32737).

[0053]

[0054] Nitrification inhibition rate (%) = (Nitrate nitrogen increment in the control group - Nitrate nitrogen increment in the sample group) / Nitrate nitrogen increment in the control group × 100% Nitrate nitrogen increment: Average value in the control group: 130.4 mg / kg; Average value in sample group 1: 84.0 mg / kg; Average value in sample group 2: 74.2 mg / kg; Nitrification inhibition rate in sample group 1: 35.2%; Nitrification inhibition rate in sample group 2: 43.1%; Absolute difference in nitrification inhibition rate of parallel samples ≤ 5%, Absolute difference between laboratories ≤ 10%.

[0055] As can be seen from Table 3 above, according to the GB / T 35113-2017 standard, the measured nitrification inhibition rate of the fertilizer synergist formula in Comparative Example 1 in the present invention is 34.7% - 36.0%, with an average value of 35.2%, which is much higher than the standard requirement of ≥ 6%. The repeatability of all parallel sample data is good (absolute difference ≤ 1.3%), indicating that the present invention has a significant inhibitory effect on nitrogen nitrification. Combining with the measured nitrification inhibition rate of the fertilizer synergist formula in Example 1, which is 42.4% - 43.6% and the average value is 43.1%, it shows that the modification of montmorillonite also has an impact on nitrogen nitrification inhibition.

[0056] 4. Add the fertilizer synergists of Example 1 and 4 and the fertilizer synergists of Comparative Example 1 and 2 to the conventional nutrient fertilizer at a ratio of 5 wt%, and then apply it according to the conventional method. At the same time, the control group only applies the conventional nutrient fertilizer, and measure the rice yield increase effect.

[0057] Soil in the planting area: Organic matter content 12.46 g / kg, Alkaline hydrolyzable nitrogen content 103.5 mg / kg, Available phosphorus content 16.4 mg / kg, Available potassium content 108.5 mg / kg; Total nutrient content of the conventional nutrient fertilizer is 40% (N:P2O5:K2O = 20:10:10).

[0058] Planting method: After applying the base fertilizer at a rate of 20 kg / mu, mechanically direct-seed the rice seeds (Dry You No. 3) at a rate of 5 kg / mu 20 days later. Apply the green-recovery fertilizer 10 days later, that is, apply ammonium sulfate at a rate of 5.5 kg / . Apply the tillering fertilizer 15 days later, that is, apply urea at a rate of 6.5 kg / .

[0059] Treatment settings: Control group (CK): Conventional nutrient fertilizers are used as the base fertilizer; Experimental group 1: Conventional nutrient fertilizers + 5 wt% of Comparative Example 1 fertilizer synergist of conventional nutrient fertilizers; Experimental group 2: Conventional nutrient fertilizers + 5 wt% of Comparative Example 2 fertilizer synergist of conventional nutrient fertilizers; Experimental group 3: Conventional nutrient fertilizers + 5 wt% of the fertilizer synergist of Example 1; Experimental group 4: Conventional nutrient fertilizers + 5 wt% of the fertilizer synergist of Example 4.

[0060] After the rice is harvested, randomly select 20 plants from each treatment to investigate the number of grains per panicle and the 1000-grain weight, and take the average value; for the effective panicle number and yield, select 50 m for each treatment 2 , calculate the effective panicle number and measure the yield, and then convert the effective panicle number and yield per unit area; the test results of each treatment are as follows:

[0061] Note: Different lowercase letters in the same column in the table represent significant differences at the 0.05 level.

[0062] As can be seen from Table 4 above, the number of grains per panicle, effective panicles, 1000-grain weight, and yield of the treatments with the added fertilizer synergist are all higher than those of the control treatment with only conventional nutrient fertilizers applied, indicating that the fertilizer synergist of the present invention can be used for deep soil application, flushing, etc. of fertilizers, and can effectively increase the yield of cash crops such as rice. Moreover, the yield increase effect of the fertilizer synergist corresponding to Example 1 is better than that of Comparative Examples 1 and 2, and the yield increase effect of the fertilizer synergist corresponding to Example 4 is even better than that of Example 1.

[0063] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A fertilizer synergist for reducing nutrient loss and inhibiting nitrification, characterized in that, Comprising by mass percentage: 95 - 98% of carboxyl cross-linked modified montmorillonite, 0.05 - 0.1% of mannan oligosaccharide, 0.1 - 0.5% of mannan, 1 - 3% of polyaspartate, 0.5 - 2% of nitrification inhibition auxiliary agent; The carboxyl cross-linked modified montmorillonite is obtained by acidifying montmorillonite, coupling and modifying it with an alkenyl silane coupling agent, and then carrying out a copolymerization reaction with methylene succinic acid.

2. The fertilizer synergist for reducing nutrient loss and inhibiting nitrification according to claim 1, characterized in that, The alkenyl silane coupling agent is at least one of vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-methacryloxypropyltriisopropoxysilane or 3-acryloxypropyltrimethoxysilane; The mass ratio of the montmorillonite to the alkenyl silane coupling agent is 1:0.05 - 0.

1.

3. The fertilizer synergist for reducing nutrient loss and inhibiting nitrification according to claim 1, characterized in that, The particle size of the montmorillonite is 10 - 200 μm; The mass ratio of the montmorillonite to methylene succinic acid is 1:0.1 - 0.

2.

4. The fertilizer synergist for reducing nutrient loss and inhibiting nitrification according to claim 1, characterized in that, The copolymerization reaction is carried out under the condition of an initiator; The initiator is one of potassium persulfate, sodium persulfate or ammonium persulfate.

5. The fertilizer synergist for reducing nutrient loss and inhibiting nitrification according to claim 1, characterized in that, The copolymerization reaction further includes adding a tertiary amino acrylate; The tertiary amino acrylate is dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate.

6. The fertilizer synergist for reducing fertilizer nutrient loss and inhibiting nitrification according to any one of claims 1-5, characterized in that, The polyaspartate is at least one of zinc polyaspartate, sodium polyaspartate, potassium polyaspartate or calcium polyaspartate.

7. The fertilizer synergist for reducing fertilizer nutrient loss and inhibiting nitrification according to any one of claims 1-5, characterized in that The nitrification inhibition auxiliary agent is 3,4-dimethylpyrazole phosphate.

8. Use of the fertilizer synergist according to any one of claims 1 - 7 in the preparation of fertilizers.

9. Use of the fertilizer synergist according to claim 8 in fertilizers, characterized in that, The fertilizer synergist is added to the fertilizer in a proportion of 1 - 20 wt%.

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