Composite granular fertilizer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of fertilizers and provides a compound granular fertilizer as well as a preparation method and application thereof. The compound granular fertilizer is composed of a slow-release fertilizer and a quick-release fertilizer, and the slow-release fertilizer comprises the following raw materials in parts by weight: 350-450 parts of a porous material, 90-110 parts of ammonium humate, 90-110 parts of phosphorus-potassium ore, 2-4 parts of a wetting agent and 4-6 parts of a suspending agent; the quick-release fertilizer comprises the following raw materials in parts by weight: 95-105 parts of a borax solution, 95-105 parts of a guar gum solution, 6-16 parts of a potassium sodium tartrate solution, 50-110 parts of a nitrogen-phosphorus-potassium fertilizer and 2.5-5.5 parts of a disintegrating agent. According to the technical scheme, the problems that the utilization rate of the compound granular fertilizer is low and slow release and quick release cannot be achieved at the same time in the related technology are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, and specifically, to a composite granular fertilizer, a preparation method thereof, and an application thereof. Background Art

[0002] With the increasing demand for efficient and precise fertilization in modern agriculture, the limitations of traditional fertilizers have gradually emerged. Although conventional chemical fertilizers (such as urea, diammonium phosphate, etc.) can quickly release nutrients, they are prone to low utilization rates (usually only 30% - 50%) due to leaching, volatilization, or fixation, and are also likely to cause environmental problems such as soil acidification and water eutrophication. While single slow-release fertilizers can extend the nutrient release period, it is difficult to meet the explosive nutrient demand of crops during critical growth periods (such as the flowering period). Therefore, granular fertilizers with both "slow-release" and "quick-release" functions have become a research hotspot in the fertilizer field. Currently, the stability of granular fertilizers is poor, especially for granular fertilizers with both "slow-release" and "quick-release" functions, there is a serious phenomenon of a large amount of powder falling off of elements, resulting in serious loss of nitrogen, phosphorus, and potassium during storage and transportation, and thus the fertilizer utilization rate is low.

[0003] Therefore, it is of great significance to develop a stable composite granular fertilizer with both "slow-release" and "quick-release" functions to improve the fertilizer utilization rate and promote the rapid growth of plants. Summary of the Invention

[0004] The present invention provides a preparation and application of a slow-release and quick-release type granular fertilizer, which solves the problems of poor stability, low utilization rate, and inability to have both slow-release and quick-release functions of composite granular fertilizers in related technologies.

[0005] The technical solution of the present invention is as follows: The present invention provides a composite granular fertilizer, which is composed of a slow-release fertilizer and a quick-release fertilizer. The slow-release fertilizer includes the following component raw materials in parts by weight: 350 - 450 parts of a porous material, 90 - 110 parts of ammonium humate, 90 - 110 parts of phosphorus and potassium ore, 2 - 4 parts of a wetting agent, 4 - 6 parts of a suspending agent; The quick-release fertilizer includes the following component raw materials in parts by weight: 95 - 105 parts of borax solution, 95 - 105 parts of guar gum solution, 6 - 16 parts of potassium sodium tartrate solution, 50 - 110 parts of nitrogen, phosphorus, and potassium fertilizer, 2.5 - 5.5 parts of a disintegrant.

[0006] In the present invention, ammonium humate has the following structure:

[0007] The slow-release fertilizer is filled in the porous material to provide space for the continuous and slow release of nitrogen, phosphorus and potassium, preventing the direct use of slow-release nitrogen, phosphorus and potassium elements in the soil and thus ensuring their effective utilization. When the nitrogen in ammonium humate (R-COONH4) is absorbed by the crop, it becomes R-COO-, which chelates calcium and magnesium ions. These void structures can provide a reaction space for R-COO- to chelate calcium and magnesium ions in phosphate and potassium ore. As the nitrogen is continuously absorbed and utilized, the humic acid releases nitrogen while chelating calcium and magnesium ions, continuously providing nutrient elements for the crop.

[0008] In the present invention, a porous material with a framework structure is used as a carrier. A substance with a slow-release fertilizer is formed into a suspension, and it is filled in the void carrier by adding a wetting agent to form a slow-release fertilizer. On the one hand, this is to prevent the loss of the slow-release fertilizer during transportation and storage, and on the other hand, to improve the use efficiency of the slow-release fertilizer. Therefore, a large amount of elements easily absorbed by the crop are coated on the surface of the carrier to form a quick-release fertilizer. To prevent the phenomenon of powder shedding of the large amount of elements, through granulation technology, a three-dimensional space structure formed by mixing guar gum solution, borax solution and sodium potassium tartrate solution is used to coat the large amount of elements on the carrier of the slow-release fertilizer, which not only prevents the powder shedding phenomenon but also well protects the slow-release fertilizer.

[0009] As a further technical solution, the weight sum of the borax solution and the guar gum solution and the weight ratio of the sodium potassium tartrate solution is 14 - 29:1; The weight ratio of the borax solution and the guar gum solution is 1:1.

[0010] In the present invention, by reasonably regulating the weight ratio among the borax solution, the guar gum solution and the sodium potassium tartrate solution, when the weight sum of the borax solution and the guar gum solution and the weight ratio of the sodium potassium tartrate solution is 14 - 29:1, the stability of the composite granular fertilizer can be further improved, the fertilizer utilization rate can be increased, and it can better promote the development of plant roots and crop growth.

[0011] As a further technical solution, the borax solution is an aqueous borax solution with a mass fraction of 3% - 4%. For example, the mass fraction can be 3%, 3.2%, 3.5%, 3.6%, 3.8%, 3.9%, 4%, preferably 3%, 4%, and more preferably 4%; The guar gum solution is an aqueous guar gum solution with a mass fraction of 5% - 8%. For example, the mass fraction can be 5%, 6%, 6.6%, 7%, 7.5%, 8%, preferably 5%, 7%, 8%, and more preferably 7%; The sodium potassium tartrate solution is an aqueous sodium potassium tartrate solution with a mass fraction of 10% - 12%. For example, the mass fraction can be 10%, 11%, 11.3%, 11.6%, 12%, preferably 11%.

[0012] As a further technical solution, the preparation method of the guar gum solution is specifically as follows: Dissolve guar gum in water, stir at 100 °C for 20 - 30 min, and cool to 20 - 25 °C to obtain the guar gum solution; The preparation method of the borax solution is specifically as follows: Dissolve borax in water to obtain the borax solution; The preparation method of the potassium sodium tartrate solution is specifically as follows: Dissolve potassium sodium tartrate in water to obtain the potassium sodium tartrate solution.

[0013] As a further technical solution, the porous material includes one or more of diatomite, zeolite, and hexagonal boron nitride, preferably diatomite and hexagonal boron nitride. When the porous material includes diatomite and hexagonal boron nitride, the weight ratio of diatomite to hexagonal boron nitride is 3 - 5:1, for example, it can be 3:1, 4:1, 5:1, and preferably 4:1.

[0014] As a further technical solution, the porous material is a composite porous material, and the raw materials of the composite porous material include a porous material and 5 - hydroxytryptophan with a weight ratio of 40:1 - 6.

[0015] In the present invention, by performing a composite treatment on the porous material with 5 - hydroxytryptophan, the active sites on the surface and inside of the porous material can be increased, the interaction between the porous material and the slow - release fertilizer can be enhanced, thereby better preventing the loss of the slow - release fertilizer during transportation and storage, and further improving the utilization rate of the composite granular fertilizer.

[0016] As a further technical solution, the preparation method of the composite porous material includes the following steps: A1. Add the porous material and the acidic solution to water, mix evenly, concentrate, wash, and dry to obtain the pretreated porous material; A2. Add the 5 - hydroxytryptophan to ethanol, mix evenly, then add the pretreated porous material, concentrate, and dry to obtain the composite porous material.

[0017] As a further technical solution, the acidic solution is a conventional acidic solution, for example, it can be a hydrochloric acid solution or a sulfuric acid solution, preferably a hydrochloric acid solution. The mass fraction of the acidic solution is 3% - 6%, for example, it can be 3%, 4%, 4.5%, 5%, 5.5%, 6%, and preferably 4%.

[0018] As a further technical solution, in step A1, the weight ratio of the porous material, the acidic solution, and water is 1:0.1 - 0.2:1.2, for example, it can be 1:0.1:1.2, 1:0.12:1.2, 1:0.14:1.2, 1:0.15:1.2, 1:0.18:1.2, 1:0.2:1.2, and preferably 1:0.2:1.2.

[0019] As a further technical solution, in steps A1 and A2, when the mixture is evenly stirred, the stirring speed is independently 110 - 150 rpm, and the stirring time is independently 30 - 50 min.

[0020] As a further technical solution, the wetting agent includes one of Tween - 80 and sodium dodecylbenzenesulfonate; The suspending agent includes one of xanthan gum and sodium carboxymethylcellulose; The disintegrant includes one of dry starch and carboxymethyl starch.

[0021] As a further technical solution, the particle size of the porous material is 30 - 50 mesh.

[0022] As a further technical solution, the phosphorus - potassium ore is composed of slow - release phosphate fertilizer and slow - release potassium fertilizer with a weight ratio of 1:1; The slow - release phosphate fertilizer includes one or both of phosphate rock and apatite; The slow - release potassium fertilizer includes one of plant ash and potassium ore.

[0023] As a further technical solution, the particle size of the phosphorus - potassium ore is 100 - 150 mesh.

[0024] As a further technical solution, the nitrogen - phosphorus - potassium fertilizer is composed of quick - release nitrogen fertilizer, quick - release phosphate fertilizer, and quick - release potassium fertilizer with a weight ratio of 2 - 4:1 - 3:2 - 4, such as 2:1:2, 3:2:3, 4:3:4, 1:1:1, and preferably 3:2:3; The quick - release nitrogen fertilizer includes one of urea and ammonium nitrate phosphate; The quick - release phosphate fertilizer includes one of monoammonium phosphate and diammonium phosphate; The quick - release potassium fertilizer includes one of potassium sulfate and potassium chloride.

[0025] As a further technical solution, the particle size of the nitrogen - phosphorus - potassium fertilizer is 100 - 150 mesh.

[0026] The present invention provides a preparation method of a composite granular fertilizer for preparing the described composite granular fertilizer, which includes the following steps: S1. Add the ammonium humate and the phosphorus - potassium ore into water, add the wetting agent and the suspending agent, mix evenly, grind to obtain a suspension, add the remaining component raw materials of the slow - release fertilizer into the suspension, disperse evenly, take out, and dry to obtain the slow - release fertilizer; S2. Mix the nitrogen - phosphorus - potassium fertilizer and the disintegrant evenly to obtain a mixture; S3. After spraying the guar gum solution on the slow-release fertilizer, add the mixture, mix well, spray the borax solution, dry, spray the potassium sodium tartrate solution, dry again, and obtain a composite granular fertilizer.

[0027] As a further technical solution, in step S1, when adding the wetting agent and the suspending agent, they are added while mechanically stirring, the stirring speed is 70-90 rpm, and the stirring time is 100-130 min; During the drying, the mixture is dried in a drying manner for 100 to 130 minutes.

[0028] As a further technical solution, in step S3, when spraying the guar gum solution, the rotation speed is 70-90 rpm, for example, 70 rpm, 75 rpm, 80 rpm, 90 rpm, preferably 80 rpm.

[0029] As a further technical solution, in step S3, during the secondary drying, the temperature is 85-90°C, for example, 85°C, 87°C, 88°C, 90°C, preferably 90°C.

[0030] The present invention proposes the application of the composite granular fertilizer or the composite granular fertilizer prepared by the preparation method in plant planting.

[0031] The working principle and beneficial effects of the present invention are: 1. In the present invention, the composite granular fertilizer utilizes the synergistic effect of borax solution, guar gum solution and sodium potassium tartrate solution on the composite granular fertilizer, which can significantly improve the stability of the composite granular fertilizer, prevent the de-powdering phenomenon of a large number of elements, and prevent the loss of nitrogen, phosphorus and potassium in the slow-release fertilizer during storage and transportation, thereby improving the utilization rate of the composite granular fertilizer, so that the composite granular fertilizer has both slow-release and quick-release functions. At present, a simple or single method is often used to deal with the de-powdering problem of granular fertilizer, which only relies on the cross-linking effect between the borax solution and the guar gum solution, so that the stability of the composite granular fertilizer is limited. The present invention adopts three solutions, namely, a borax solution, a guar gum solution and a potassium sodium tartrate solution. After the borax solution and the guar gum solution initially form a three-dimensional network space structure, under the action of the potassium sodium tartrate solution, the composite granular fertilizer can form a stable structure, greatly reducing the powdering phenomenon of the granules during storage, transportation and use. Therefore, through the precise coordinated regulation of nutrient release, the dual effects of slow release and quick release of the fertilizer are achieved, the nutrient requirements of crops at different growth stages are met, and the needs of rapid response and long-term supply can be achieved.

[0032] 2. In the present invention, the composite granular fertilizer can improve soil structure, increase soil organic matter content, improve soil water and fertilizer retention capacity, promote root development and crop growth, improve fertilizer utilization, reduce waste, and reduce the number of fertilization times. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work fall within the scope of protection of the present invention.

[0034] In the following examples and comparative examples: Ammonium humate, black powder, with a humic acid content of 51.1%, a moisture content of 14.6%, and a nitrogen content of 21%, purchased from Shanxi Tianfengyuan Humic Acid Technology Co., Ltd.; Phosphate rock, with a particle size of 100 mesh, purchased from Guizhou Kai Phosphorus (Group) Co., Ltd.; Apatite, with a particle size of 100 mesh, purchased from Shandong Maina New Materials Co., Ltd.; Plant ash: self-made, after burning branches, passing through a 100-mesh sieve; Potassium ore, with a particle size of 100 mesh, purchased from Lingshou County Shengbang Mineral Products Processing Factory; Diatomite, with a particle size of 30 mesh; Cubic boron nitride, with a particle size of 30 mesh; Xanthan gum, purchased from Hebei Jinfeng Starch and Sugar Alcohol Co., Ltd.; Sodium carboxymethyl cellulose, purchased from Hebei Jinfeng Starch and Sugar Alcohol Co., Ltd.; Urea, with a nitrogen content of 46%; Ammonium nitrate phosphate, with a nitrogen content of 30.76%; Monoammonium phosphate, with a nitrogen content of 12% and a phosphorus content of 61%; Diammonium phosphate, with a nitrogen content of 20% and a phosphorus content of 54%; Potassium sulfate, with a potassium content of 52%; Potassium chloride, with a potassium content of 62%; Dry starch, specifically corn starch, purchased from Hebei Jinfeng Starch and Sugar Alcohol Co., Ltd.; Carboxymethyl starch, purchased from Hebei Jinfeng Starch and Sugar Alcohol Co., Ltd.

[0035] Example 1 A preparation method of a composite granular fertilizer, comprising the following steps: S1. Add 90 g of ammonium humate, 45 g of phosphate rock, and 45 g of plant ash to 300 mL of water. While mechanically stirring at 70 rpm, add 2 g of Tween - 80 and 4 g of xanthan gum, stir for 130 min, mix evenly, grind to obtain a suspension. Add 262.5 g of diatomaceous earth and 87.5 g of hexagonal boron nitride to the suspension, disperse evenly, take out, and dry for 100 min to obtain a slow - release fertilizer; S2. Mix 20 g of urea, 10 g of monoammonium phosphate, 20 g of potassium sulfate, and 2.5 g of dry starch evenly to obtain a mixture; S3. Put the slow - release fertilizer into a disc granulator. While rotating at 70 rpm, first spray 95 g of an aqueous solution of guar gum with a mass fraction of 7% on the slow - release fertilizer, then add the mixture. After the mixture is evenly distributed, spray 95 g of an aqueous solution of borax with a mass fraction of 4%, dry, and then spray 6 g of an aqueous solution of potassium sodium tartrate with a mass fraction of 11%. Dry again at 85 °C to obtain a compound granular fertilizer.

[0036] Example 2 A preparation method of a compound granular fertilizer, comprising the following steps: S1. Add 100 g of ammonium humate, 50 g of phosphate rock, and 50 g of plant ash to 300 mL of water. While mechanically stirring at 80 rpm, add 3 g of Tween - 80 and 5 g of sodium carboxymethyl cellulose, stir for 120 min, mix evenly, grind to obtain a suspension. Add 320 g of diatomaceous earth and 80 g of hexagonal boron nitride to the suspension, disperse evenly, take out, and dry for 120 min to obtain a slow - release fertilizer; S2. Mix 30 g of urea, 20 g of monoammonium phosphate, 30 g of potassium sulfate, and 4 g of carboxymethyl starch evenly to obtain a mixture; S3. Put the slow - release fertilizer into a disc granulator. While rotating at 80 rpm, first spray 97 g of an aqueous solution of guar gum with a mass fraction of 7% on the slow - release fertilizer, then add the mixture. After the mixture is evenly distributed, spray 97 g of an aqueous solution of borax with a mass fraction of 4%, dry, and then spray 16 g of an aqueous solution of potassium sodium tartrate with a mass fraction of 11%. Dry again at 90 °C to obtain a compound granular fertilizer.

[0037] Example 3 A preparation method of a compound granular fertilizer, comprising the following steps: S1. Add 110 g of ammonium humate, 55 g of apatite, and 55 g of potassium ore to 300 mL of water. While mechanically stirring at 90 rpm, add 4 g of sodium dodecylbenzenesulfonate and 6 g of sodium carboxymethyl cellulose, stir for 100 min, mix evenly, grind to obtain a suspension. Add 375 g of diatomaceous earth and 75 g of hexagonal boron nitride to the suspension, disperse evenly, take out, and dry for 130 min to obtain a slow - release fertilizer; S2. Mix 40 g of ammonium nitrate phosphate, 30 g of diammonium phosphate, 40 g of potassium chloride and 5.5 g of carboxymethyl starch evenly to obtain a mixture; S3. Put the slow-release fertilizer into a disk granulator. First, spray 105 g of an aqueous solution of guar gum with a mass fraction of 7% on the slow-release fertilizer at 90 rpm, then add the mixture. After the mixture is even, spray 105 g of an aqueous solution of borax with a mass fraction of 4%, dry, and then spray 16 g of an aqueous solution of potassium sodium tartrate with a mass fraction of 11%. Dry again at 90 °C to obtain the compound granular fertilizer.

[0038] Example 4 The difference between this example and Example 2 is only that, in this example, the addition amount of the aqueous solution of guar gum is 102 g, the addition amount of the aqueous solution of borax is 102 g, and the addition amount of the aqueous solution of potassium sodium tartrate is 6 g.

[0039] Example 5 The difference between this example and Example 2 is only that, in this example, the addition amount of the aqueous solution of guar gum is 98 g, the addition amount of the aqueous solution of borax is 98 g, and the addition amount of the aqueous solution of potassium sodium tartrate is 14 g.

[0040] Example 6 The difference between this example and Example 2 is only that, in this example, the addition amount of the aqueous solution of guar gum is 101.5 g, the addition amount of the aqueous solution of borax is 101.5 g, and the addition amount of the aqueous solution of potassium sodium tartrate is 7 g.

[0041] Example 7 The difference between this example and Example 6 is only that, in this example, the porous material is a composite porous material, and the preparation method of the composite porous material includes the following steps: A1. Add 320 g of diatomite, 80 g of hexagonal boron nitride and 80 g of a hydrochloric acid solution with a mass fraction of 4% to 480 mL of water, stir at 140 rpm for 40 min, mix evenly, concentrate, wash, and dry to obtain a pretreated porous material; A2. Add 10 g of 5-hydroxytryptophan to 400 mL of ethanol, stir at 140 rpm for 40 min, mix evenly, then add the above pretreated porous material, concentrate, and dry to obtain the composite porous material.

[0042] Example 8 The difference between this example and Example 7 is only that, in the preparation process of the composite porous material in this example, the addition amount of 5-hydroxytryptophan is 60 g.

[0043] Example 9 The difference between this example and Example 7 is only that, in the preparation process of the composite porous material in this example, the addition amount of 5-hydroxytryptophan is 30 g.

[0044] Example 10 The difference between this example and Example 7 is only that in the preparation process of the composite porous material in this example, the addition amount of 5-hydroxytryptophan is 35 g.

[0045] Comparative Example 1 The difference between this comparative example and Example 1 is only that in this comparative example, no aqueous solution of potassium sodium tartrate is added, 98 g of aqueous solution of guar gum is added, and 98 g of aqueous solution of borax is added.

[0046] Comparative Example 2 The difference between this comparative example and Example 1 is only that in this comparative example, no aqueous solution of guar gum is added, 190 g of aqueous solution of borax is added, and 6 g of aqueous solution of potassium sodium tartrate is added; In the preparation method of a composite granular fertilizer, step S3 is specifically as follows: S3. Put the slow-release fertilizer into a disk granulator, first spray 190 g of 4% aqueous solution of borax on the slow-release fertilizer at 70 rpm, then add the mixture. After the mixture is uniform, spray 6 g of 11% aqueous solution of potassium sodium tartrate, and dry at 85 °C to obtain the composite granular fertilizer.

[0047] Comparative Example 3 The difference between this comparative example and Example 1 is only that in this comparative example, no aqueous solution of borax is added, 190 g of aqueous solution of guar gum is added, and 6 g of aqueous solution of potassium sodium tartrate is added; In the preparation method of a composite granular fertilizer, step S3 is specifically as follows: S3. Put the slow-release fertilizer into a disk granulator, first spray 190 g of 7% guar gum solution on the slow-release fertilizer at 70 rpm, then add the mixture. After the mixture is uniform, spray 6 g of 11% potassium sodium tartrate solution, and dry at 85 °C to obtain the composite granular fertilizer.

[0048] Comparative Example 4 The difference between this comparative example and Example 1 is only that in this comparative example, both the aqueous solution of guar gum and the aqueous solution of borax are replaced with the same amount of water.

[0049] Comparative Example 5 The difference between this comparative example and Example 1 is only that in this comparative example, no dry starch is added.

[0050] Comparative Example 6 The difference between this comparative example and Example 1 is only that in this comparative example, no diatomaceous earth and cubic boron nitride are added; In the preparation method of a composite granular fertilizer, step S1 is specifically as follows: S1. Add 90 g of ammonium humate, 45 g of phosphate rock, and 45 g of plant ash to 300 mL of water. While mechanically stirring at 70 rpm, add 2 g of Tween - 80 and 4 g of xanthan gum, stir for 130 min, mix evenly, grind to obtain a suspension. Concentrate the suspension and dry it to obtain a slow - release fertilizer.

[0051] Experimental Examples Perform the following performance tests on the composite granular fertilizers prepared in Examples 1 - 10 and Comparative Examples 1 - 6: ① Hardness test: Use a KQ - 3 type granule strength tester (instrument number: 91551) to test the hardness of the composite granular fertilizer.

[0052] ② Application effect test: Plant 3 seeds of Brassica rapa chinensis in each flower pot. Use the composite granular fertilizer as the base fertilizer, and use vermiculite as the soil matrix. In each pot, mix 1 kg of vermiculite and 50 g of the composite granular fertilizer, then add 200 mL of water. The blank test is: Replace 50 g of the composite granular fertilizer with an equal amount of water; The comparative test is: Replace 50 g of the composite granular fertilizer with an equal amount of slow - release fertilizer; Measure the leaf area of Brassica rapa chinensis on the 30th day.

[0053] The test results are shown in Table 1.

[0054] Table 1 Test results of hardness and plant growth leaf area

[0055] As can be seen from Table 1, compared with Comparative Examples 1 - 6, the hardness of the composite granular fertilizers prepared in Examples 1 - 10 is increased, reaching at least 60 N, indicating that the composite granular fertilizers obtained by this solution have good hardness and good stability, and can effectively prevent powdering during storage and transportation.

[0056] Compared with Comparative Examples 1 - 6, the blank test, and the comparative test, when the composite granular fertilizers prepared in Examples 1 - 10 are used for plants, the average leaf area of Brassica rapa chinensis on the 30th day can be effectively increased, indicating that the composite granular fertilizers obtained by this solution can effectively promote root development and crop growth, and improve fertilizer utilization rate.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite granular fertilizer is composed of a slow-release fertilizer and a quick-release fertilizer, and is characterized in that The slow-release fertilizer comprises the following components in parts by weight: 350 - 450 parts of porous material, 90 - 110 parts of ammonium humate, 90 - 110 parts of phosphorus and potassium ore, 2 - 4 parts of wetting agent, 4 - 6 parts of suspending agent; The quick-release fertilizer comprises the following components in parts by weight: 95 - 105 parts of borax solution, 95 - 105 parts of guar gum solution, 6 - 16 parts of potassium sodium tartrate solution, 50 - 110 parts of nitrogen, phosphorus and potassium fertilizer, 2.5 - 5.5 parts of disintegrant.

2. The compound granular fertilizer according to claim 1, characterized in that, The weight ratio of the sum of the weights of the borax solution and the guar gum solution to the weight of the potassium sodium tartrate solution is 14 - 29:1; The weight ratio of the borax solution to the guar gum solution is 1:

1.

3. The compound granular fertilizer according to claim 1, wherein, The porous material includes one or more of diatomite, zeolite, and hexagonal boron nitride. When the porous material includes diatomite and hexagonal boron nitride, the weight ratio of diatomite to hexagonal boron nitride is 3 - 5:

1.

4. A composite granular fertilizer according to claim 1, characterized in that The porous material is a composite porous material, and the raw materials of the composite porous material include a porous material and 5-hydroxytryptophan in a weight ratio of 40:1 - 6.

5. The composite granular fertilizer according to claim 4, wherein, The preparation method of the composite porous material comprises the following steps: A1. Add the porous material and the acidic solution into water, mix evenly, concentrate, wash, and dry to obtain a pretreated porous material; A2. Add the 5-hydroxytryptophan into ethanol, mix evenly, then add the pretreated porous material, concentrate, and dry to obtain the composite porous material.

6. The composite granular fertilizer according to claim 1, wherein, The wetting agent includes one of Tween - 80 and sodium dodecylbenzenesulfonate; The suspending agent includes one of xanthan gum and sodium carboxymethylcellulose; The disintegrant includes one of dry starch and carboxymethyl starch.

7. The compound granular fertilizer according to claim 1, wherein, The phosphorus and potassium ore is composed of slow-release phosphate fertilizer and slow-release potassium fertilizer in a weight ratio of 1:1; The slow-release phosphate fertilizer includes one or two of phosphate rock and apatite; The slow-release potassium fertilizer includes one of plant ash and potassium ore.

8. A composite granular fertilizer according to claim 1, wherein The nitrogen, phosphorus and potassium fertilizer is composed of quick-release nitrogen fertilizer, quick-release phosphate fertilizer, and quick-release potassium fertilizer in a weight ratio of 2 - 4:1 - 3:2 - 4; The quick-release nitrogen fertilizer includes one of urea and ammonium nitrate phosphate; The quick-release phosphate fertilizer includes one of monoammonium phosphate and diammonium phosphate; The quick-release potassium fertilizer includes one of potassium sulfate and potassium chloride.

9. A preparation method of a composite granular fertilizer for preparing a composite granular fertilizer as described in any one of claims 1 to 8, characterized in that, Comprises the following steps: S1. Add the ammonium humate and the phosphorus and potassium ore into water, add the wetting agent and the suspending agent, mix evenly, grind to obtain a suspension, add the remaining component raw materials of the slow-release fertilizer into the suspension, disperse evenly, take out, and dry to obtain the slow-release fertilizer; S2. Mix the nitrogen, phosphorus and potassium fertilizer and the disintegrant evenly to obtain a mixture; S3. Spray the guar gum solution on the slow-release fertilizer, then add the mixture, mix evenly, spray the borax solution, dry, and then spray the potassium sodium tartrate solution, and dry again to obtain the composite granular fertilizer.

10. Application of a composite granular fertilizer according to any one of claims 1 - 8 or a composite granular fertilizer prepared by the preparation method according to claim 9 in plant cultivation.

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