A water-soluble seaweed compound fertilizer and its preparation method and application

Abstract

The invention discloses a water-soluble seaweed compound fertilizer and a preparation method and application thereof. The water-soluble seaweed compound fertilizer comprises the following raw materials: urea, potassium dihydrogen phosphate, potassium nitrate, seaweed extract, microbial powder and trace elements, wherein the trace elements comprise fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron, and the weight ratio of the fulvic acid chelated zinc, the fulvic acid chelated iron, the fulvic acid chelated manganese and the fulvic acid chelated boron is 1-2:1-2:1-2:1-2. The compound fertilizer prepared by the preparation method of the invention can improve fertilizer utilization rate, regulate soil, and improve planting capacity and quality, and has broad application prospects in crop planting.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer manufacturing, and in particular to a water-soluble seaweed compound fertilizer and a preparation method and application thereof. Background Art

[0002] At present, our fertilizers only focus on the supply of major nutrients, such as the three major elements of nitrogen, phosphorus and potassium. But in fact, the nutritional needs of plants are relatively comprehensive. They also need medium-level elements such as calcium, magnesium, and sulfur, and trace elements such as zinc, boron, manganese, iron, copper, molybdenum, and silicon. In addition to the supply of inorganic salt elements, it is far from enough. Some functional substances need to be added, such as improving the plant's stress resistance, drought resistance, cold resistance, lodging resistance, crack prevention, increasing fruit sugar content, promoting root growth, and protecting flowers and fruits. In general, plants now also need to "eat well and eat right" to make plants grow better.

[0003] Therefore, the development of new fertilizers has an indescribable role and significance in energy conservation and consumption reduction in the agricultural sector. Summary of the invention

[0004] The purpose of the present invention is to provide a water-soluble seaweed compound fertilizer and a preparation method and application thereof. The compound fertilizer solves the problem of lack of organic and inorganic elements, solves the problem of carbonization of functional substances, improves the salt tolerance of microorganisms, and can improve fertilizer utilization, condition soil, and improve planting capacity and crop quality.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a water-soluble seaweed compound fertilizer, comprising the following raw materials: urea, potassium dihydrogen phosphate, potassium nitrate, seaweed extract, microbial powder and trace elements, wherein the trace elements include fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron, and the weight ratio of the fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron is 1-2:1-2:1-2:1-2.

[0007] Preferably, the water-soluble seaweed compound fertilizer comprises the following raw materials in parts by weight: 15-30 parts of urea, 15-30 parts of potassium dihydrogen phosphate, 15-30 parts of potassium nitrate, 5-35 parts of seaweed extract, 1-5 parts of microbial powder and 0.5-5 parts of trace elements.

[0008] Preferably, the method for preparing the seaweed extract comprises the following steps:

[0009] S1, mixing and crushing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1-3:1-3:1-3, and adding 5-15 times the volume of water to dissolve and disperse to obtain a dispersion;

[0010] S2, adding compound enzyme 1 to the above dispersion for enzymatic treatment, wherein the compound enzyme 1 is composed of amylase, sucrase, cellulase, pectinase and neutral protease, filtering to obtain an enzymatic solution;

[0011] S3, concentrating the enzymatic hydrolysate, and freeze-drying the concentrate to obtain the seaweed extract.

[0012] There are many plant hormones in seaweed. Among them, the plant hormones in Ascophyllum nodosum include growth hormone, cytokinin and abscisic acid; the plant hormones in Sargassum include cytokinin and gibberellin; the plant hormones in Laminaria japonica include auxin and abscisic acid. Seaweed enzymatic extract is a natural soil conditioner that can promote crop seed germination and plant growth and improve crop quality.

[0013] Furthermore, the added amounts of amylase, sucrase, cellulase, pectinase and neutral protease in the complex enzyme 1 of S2 are 650-1200 U / g, 500-1000 U / g, 1000-1500 U / g, 800-1500 U / g and 400-800 U / g, respectively.

[0014] Furthermore, the enzymolysis temperature in S2 is 30-42° C., and the enzymolysis time is 1-5 h.

[0015] Preferably, the microbial powder is a composite microbial powder, and the composite microbial powder includes at least two of Bacillus subtilis, Chromnocardia corallii, Bacillus licheniformis and Streptomyces jingyangensis.

[0016] The microorganisms described in the present invention are all known strains and can be obtained commercially.

[0017] Preferably, the effective viable count of each type of bacteria in the composite microbial powder is ≥5×10 9 cfu / g.

[0018] Preferably, the composite microbial powder is pyrite-based composite microbial powder.

[0019] Preferably, the preparation method of the pyrite-based composite microbial powder is: pyrite and composite microorganisms are mixed, stirred, and dried to obtain the pyrite-based composite microbial powder loaded with the composite bacterial agent.

[0020] In a second aspect, the present invention provides a method for preparing a water-soluble seaweed compound fertilizer, comprising the following steps:

[0021] S1, sending urea into the first tank of the high tower reactor for high-speed stirring and dissolving, sending potassium dihydrogen phosphate and potassium nitrate into the second tank for high-speed stirring and dissolving, and sending seaweed extract and trace elements into the third tank for stirring and dissolving;

[0022] S2, sending the material in the first tank into the second tank for stirring and mixing, and then sending it into the third tank for stirring and mixing;

[0023] S3, sending the mixed materials in the third tank to the granulator for granulation, air cooling, screening, and rapid freezing;

[0024] S4, mixing the microbial powder and the seaweed enzymatic hydrolysate, and spraying the mixture onto the surface of the S3 frozen particles to obtain a water-soluble seaweed compound fertilizer.

[0025] Preferably, the method for preparing the seaweed hydrolysate in S4 comprises the following steps:

[0026] S1, mixing and crushing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1-3:1-3:1-3, and adding 5-15 times the volume of water to dissolve and disperse to obtain a dispersion;

[0027] S2, adding composite enzyme 2 to the above dispersion for enzymatic treatment, wherein the composite enzyme 2 is composed of saccharifying enzyme, cellulase and pectinase, and the added amounts of saccharifying enzyme, cellulase and pectinase in the composite enzyme 2 are 800-1000U / g, 1000-1500U / g and 800-1500U / g respectively, filtering to obtain enzymatic solution.

[0028] In a third aspect, the present invention provides an application of a water-soluble seaweed compound fertilizer in crop planting.

[0029] Preferably, the crops include vegetables, melons, fruit trees, potatoes and tobacco.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The water-soluble seaweed compound fertilizer provided by the present invention adopts inorganic salts, organic seaweed extracts, and microorganisms in combination, which work in a coordinated manner to jointly improve fertilizer utilization, condition soil, increase planting capacity, and improve crop quality.

[0032] The inorganic salt of the present invention comprises urea, potassium dihydrogen phosphate and potassium nitrate, and the high-salt substances such as nitrogen, phosphorus and potassium are appropriately reduced. Potassium dihydrogen phosphate is used instead of ordinary monoammonium phosphate, so that the nutrient reduction effect remains unchanged.

[0033] The trace elements of the present invention are chelated trace elements, including fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron. The scarce elements are chelated in advance using a chelating agent to avoid zinc from reacting and combining with phosphorus easily, thereby affecting the fertilizer effect.

[0034] The seaweed extract of the present invention comprises extracts of Ascophyllum nodosum, Sargassum and Laminaria japonica, thereby obtaining a variety of biostimulants and improving the growth efficiency of crops.

[0035] The microbial powder of the present invention comprises a plurality of microbial strains and is coated on the surface of fertilizer particles, thereby improving the salt tolerance of the microbial strains and obtaining better fertilizer efficiency.

[0036] The water-soluble seaweed compound fertilizer provided by the invention has good water solubility, high content of biological organic matter, and wide application modes. It can be applied by root irrigation or spraying, is suitable for a variety of crops, and has good application prospects. DETAILED DESCRIPTION

[0037] Below by specific embodiment, the specific implementation mode of this explanation technical scheme is further described, these embodiments are for the detailed description of this technical scheme, rather than for limiting this technical scheme. Based on the embodiment in this description, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of this description. Unless otherwise specified, the reagent, method and equipment used in the present invention are conventional reagents, methods and equipment in the art, and the reagents and materials used in the following examples are all commercially available.

[0038] Bacillus subtilis, with the deposit number ATCC19659, was purchased from Shenzhen Zike Biological Co., Ltd.; Chromanocardia corallii, with the deposit number ACCC40100, was purchased from Qiyi Biotechnology (Shanghai) Co., Ltd.; Bacillus licheniformis, with the deposit number ATCC11946, was purchased from Qiyi Biotechnology (Shanghai) Co., Ltd.; Streptomyces jingyangensis, with the deposit number ACCC40126, was purchased from Shanghai Fuxiang Biological Co., Ltd.

[0039] Preparation Example 1

[0040] This preparation example provides a seaweed extract, and the preparation method thereof comprises the following steps:

[0041] S1, mixing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1:1:1, and crushing them, adding 7 times the volume of water to dissolve and disperse them to obtain a dispersion;

[0042] S2, adding composite enzyme 1 to the above dispersion for enzymolysis, controlling the temperature to 40°C, and performing the enzymolysis reaction for 2.5h, wherein the composite enzyme 1 is composed of amylase, sucrase, cellulase, pectinase and neutral protease, and the addition amounts of amylase, sucrase, cellulase, pectinase and neutral protease in the composite enzyme are 1000U / g, 800U / g, 1200U / g, 1000U / g and 500U / g, respectively, filtering to obtain an enzymolysis solution;

[0043] S3, concentrating the enzymatic hydrolysate, and freeze-drying the concentrate to obtain the seaweed extract.

[0044] Preparation Example 2

[0045] This preparation example provides a microbial powder, and the preparation method thereof is as follows:

[0046] The microbial strain and pyrite are uniformly mixed in a weight ratio of 3:1, wherein the microbial strain includes Bacillus subtilis, Nocardia corallii, Bacillus licheniformis and Streptomyces jingyangensis in a weight ratio of 2:1:1:1, and the mixture is freeze-dried to obtain pyrite-based composite microbial powder.

[0047] The effective viable count of the microbial powder is ≥25×10 9 cfu / g.

[0048] Example 1

[0049] The water-soluble seaweed compound fertilizer provided in this embodiment is composed of the following raw materials in parts by weight: 20 parts of urea, 15 parts of potassium dihydrogen phosphate, 15 parts of potassium nitrate, 25 parts of seaweed extract, 4 parts of composite microbial powder, 0.8 parts of fulvic acid chelated zinc, 1 part of fulvic acid chelated iron, 0.5 parts of fulvic acid chelated manganese and 0.5 parts of fulvic acid chelated boron.

[0050] The composite microbial powder comprises Bacillus subtilis, Nocardia corallii, Bacillus licheniformis and Streptomyces jingyangensis in a weight ratio of 2:1:1:1, wherein the effective viable count of each bacterium is ≥5×10 9 cfu / g, the total effective viable bacteria count in the water-soluble seaweed compound fertilizer is ≥25×10 9 cfu / g.

[0051] The preparation method of the water-soluble seaweed compound fertilizer of this embodiment comprises the following steps:

[0052] S1, sending urea into the first tank of the high tower reactor for high-speed stirring and dissolving, sending potassium dihydrogen phosphate and potassium nitrate into the second tank for high-speed stirring and dissolving, and sending seaweed extract and trace elements into the third tank for stirring and dissolving;

[0053] S2, sending the material in the first tank into the second tank for stirring and mixing, and then sending it into the third tank for stirring and mixing;

[0054] S3, sending the mixed materials in the third tank to the granulator for granulation, air cooling, screening, and rapid freezing;

[0055] S4, after fully mixing the microbial powder and the seaweed enzymatic hydrolysate, spraying the mixture onto the surface of the S3 frozen particles to obtain a water-soluble seaweed compound fertilizer.

[0056] The method for preparing the seaweed hydrolysate in step S4 comprises the following steps:

[0057] S1, mixing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 2:1:1, crushing, adding 7 times volume of water to dissolve and disperse, and obtaining a dispersion;

[0058] S2, adding composite enzyme 2 to the above dispersion for enzymatic hydrolysis for 2.5 hours, controlling the temperature at 40°C, wherein the composite enzyme 2 is composed of saccharifying enzyme, cellulase and pectinase, and the added amounts of saccharifying enzyme, cellulase and pectinase in the composite enzyme 2 are 800U / g, 1000U / g and 800U / g respectively, filtering to obtain enzymatic hydrolyzate.

[0059] Example 2

[0060] The water-soluble seaweed compound fertilizer provided in this embodiment is composed of the following raw materials in parts by weight: 20 parts of urea, 15 parts of potassium dihydrogen phosphate, 15 parts of potassium nitrate, 25 parts of seaweed extract, 4 parts of pyrite-based composite microbial powder, 0.8 parts of fulvic acid chelated zinc, 1 part of fulvic acid chelated iron, 0.5 parts of fulvic acid chelated manganese and 0.5 parts of fulvic acid chelated boron.

[0061] The preparation method of the water-soluble seaweed compound fertilizer of this embodiment comprises the following steps:

[0062] S1, sending urea into the first tank of the high tower reactor for high-speed stirring and dissolving, sending potassium dihydrogen phosphate and potassium nitrate into the second tank for high-speed stirring and dissolving, and sending seaweed extract and trace elements into the third tank for stirring and dissolving;

[0063] S2, sending the material in the first tank into the second tank for stirring and mixing, and then sending it into the third tank for stirring and mixing;

[0064] S3, sending the mixed materials in the third tank to the granulator for granulation, air cooling, screening, and rapid freezing;

[0065] S4, after fully mixing the microbial powder and the seaweed enzymatic hydrolysate, spraying the mixture onto the surface of the S3 frozen particles to obtain a water-soluble seaweed compound fertilizer.

[0066] The method for preparing the seaweed hydrolysate in step S4 comprises the following steps:

[0067] S1, mixing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 2:1:1, and crushing them, adding 7 times the volume of water to dissolve and disperse them to obtain a dispersion;

[0068] S2, adding composite enzyme 2 to the above dispersion for enzymatic hydrolysis for 2.5 hours, controlling the temperature at 40°C, wherein the composite enzyme 2 is composed of saccharifying enzyme, cellulase and pectinase, and the added amounts of saccharifying enzyme, cellulase and pectinase in the composite enzyme 2 are 800U / g, 1000U / g and 800U / g respectively, filtering to obtain enzymatic hydrolyzate.

[0069] Example 3

[0070] The water-soluble seaweed compound fertilizer provided in this embodiment is composed of the following raw materials in parts by weight: 30 parts of urea, 20 parts of potassium dihydrogen phosphate, 20 parts of potassium nitrate, 10 parts of seaweed extract, 3 parts of composite microbial powder, 0.8 parts of fulvic acid chelated zinc, 1 part of fulvic acid chelated iron, 0.5 parts of fulvic acid chelated manganese and 0.5 parts of fulvic acid chelated boron.

[0071] The composite microbial powder comprises Bacillus subtilis, Nocardia corallii, Bacillus licheniformis and Streptomyces jingyangensis in a weight ratio of 1:1:1:1, wherein the effective viable count of each bacterium is ≥5×10 9 cfu / g, the total effective viable bacteria count in the water-soluble seaweed compound fertilizer is ≥20×10 9 cfu / g.

[0072] The preparation method of the water-soluble seaweed compound fertilizer of this embodiment comprises the following steps:

[0073] S1, sending urea into the first tank of the high tower reactor for high-speed stirring and dissolving, sending potassium dihydrogen phosphate and potassium nitrate into the second tank for high-speed stirring and dissolving, and sending seaweed extract and trace elements into the third tank for stirring and dissolving;

[0074] S2, sending the material in the first tank into the second tank for stirring and mixing, and then sending it into the third tank for stirring and mixing;

[0075] S3, sending the mixed materials in the third tank to the granulator for granulation, air cooling, screening, and rapid freezing;

[0076] S4, after fully mixing the microbial powder and the seaweed enzymatic hydrolysate, spraying the mixture onto the surface of the S3 frozen particles to obtain a water-soluble seaweed compound fertilizer.

[0077] The method for preparing the seaweed hydrolysate in step S4 comprises the following steps:

[0078] S1, mixing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1:1:1, and crushing them, adding 6 times the volume of water to dissolve and disperse them to obtain a dispersion;

[0079] S2, adding composite enzyme 2 to the above dispersion for enzymatic hydrolysis for 2.5 hours, controlling the temperature at 40°C, wherein the composite enzyme 2 is composed of saccharifying enzyme, cellulase and pectinase, and the added amounts of saccharifying enzyme, cellulase and pectinase in the composite enzyme 2 are 900U / g, 1000U / g and 800U / g respectively, filtering to obtain enzymatic hydrolysis solution.

[0080] Comparative Example 1

[0081] The difference from Example 3 is that no seaweed extract is added, and the other aspects are the same.

[0082] The preparation method is the same as Example 3.

[0083] Comparative Example 2

[0084] The difference from Example 3 is that only the seaweed extract is replaced by the Ascophyllum nodosum extract, the preparation method is the same as that of Preparation Example 1, and the rest are the same.

[0085] The preparation method is the same as Example 3.

[0086] Comparative Example 3

[0087] The difference from Example 3 is that the microbial powder is freeze-dried powder of Bacillus subtilis, and the rest are the same.

[0088] The preparation method is the same as Example 3.

[0089] Comparative Example 4

[0090] The difference from Example 3 is that the trace elements are zinc, iron, manganese and boron, which are not chelated by fulvic acid, and the others are the same.

[0091] The preparation method is the same as Example 3.

[0092] Comparative Example 5

[0093] The difference from Example 3 is that no seaweed extract is added, the microbial powder is freeze-dried powder of Bacillus subtilis, the trace elements are zinc, iron, manganese and boron, which are not chelated by fulvic acid, and the rest are the same.

[0094] The preparation method is the same as Example 3.

[0095] Comparative Example 6

[0096] The difference from Example 3 is that potassium dihydrogen phosphate is replaced by phosphorus nitrate and monoammonium phosphate, potassium nitrate is replaced by potassium sulfate, and the rest are the same.

[0097] The preparation method is the same as Example 3.

[0098] Comparative Example 7

[0099] The difference from Example 3 is that potassium dihydrogen phosphate is replaced by phosphorus nitrate and monoammonium phosphate, potassium nitrate is replaced by potassium sulfate, no seaweed extract is added, the microbial powder is freeze-dried powder of Bacillus subtilis, the trace elements are zinc, iron, manganese and boron, and are not chelated by fulvic acid, and the rest are the same.

[0100] The preparation method is the same as Example 3.

[0101] Comparative Example 8

[0102] The difference from Example 1 is that the preparation method does not include step S4, and the rest are the same.

[0103] Application Example 1

[0104] The test site is located in a vegetable garden in Guangzhou City, Guangdong Province, where lettuce has been grown for 5 years. The variety grown is Taihu 695 lettuce. The same size of land was selected in the vegetable garden, and the compound fertilizers prepared in Examples 1-3 and Comparative Examples 1-7 were applied to different plots. The fertilizer usage of all test groups was the same, all applied as base fertilizer once, and no topdressing was performed during the growth period. With clear water as the control group, the fertilizer application rate was 10kg / mu, and leaf spraying was adopted. Other management methods such as watering were carried out according to local conventional management methods.

[0105] The lettuce yield (kg / mu) and soluble sugar content (%) were statistically analyzed. The soluble sugar content was determined using the Fehling's reagent calibration method. The results are shown in Table 1.

[0106] Table 1 Effects on lettuce yield and soluble sugar content

[0107] Yield (kg / mu) Soluble sugar content (%) Example 1 3514.6 3.05 Example 2 3651.5 3.14 Example 3 3439.2 2.73 Comparative Example 1 2784.5 2.37 Comparative Example 2 2995.6 2.49 Comparative Example 3 3056.2 2.57 Comparative Example 4 3241.6 2.64 Comparative Example 5 1984.3 1.82 Comparative Example 6 3301.5 2.69 Comparative Example 7 1637.8 1.51 Comparative Example 8 2596.7 2.18

[0108] It can be seen from Table 1 that the water-soluble seaweed compound fertilizer provided by Examples 1-3 of the present invention can significantly increase the yield and soluble sugar content of lettuce, and Example 2 has the highest yield per mu and soluble sugar content.

[0109] Compared with Example 3, Comparative Example 1 differs in that no seaweed extract is added to the compound fertilizer, and the per-acre yield and soluble sugar content are lower than those in Example 3, indicating that seaweed extract can improve lettuce yield and quality.

[0110] Compared with Example 3, the difference in Comparative Example 2 is that the seaweed extract in the compound fertilizer is replaced by Ascophyllum nodosum extract, and the per mu yield and soluble sugar content are both lower than those in Example 3, indicating that the seaweed extract provided by the present invention can better improve the yield and quality of lettuce.

[0111] Compared with Example 3, Comparative Example 3 differs in that the microbial powder in the compound fertilizer is freeze-dried powder of Bacillus subtilis, and does not contain Coraline chromonocardia, Bacillus licheniformis and Jingyang Streptomyces. The yield per mu and the soluble sugar content are both lower than those in Example 3, indicating that the microbial powder provided by the present invention can better improve the yield and quality of lettuce.

[0112] Compared with Example 3, Comparative Example 4 differs in that the trace elements in the compound fertilizer are zinc, iron, manganese and boron, which are not chelated with fulvic acid. The yield per mu and the soluble sugar content are both lower than those in Example 3, indicating that the use of fulvic acid to chelate zinc, iron, manganese and boron can improve the yield and quality of lettuce.

[0113] Compared with Example 3, Comparative Example 5 differs in that no seaweed extract is added to the compound fertilizer, the microbial powder is freeze-dried powder of Bacillus subtilis, the trace elements zinc, iron, manganese and boron are not chelated with fulvic acid, and the per mu yield and soluble sugar content are significantly lower than those in Example 3, and lower than those in Comparative Examples 1-4.

[0114] Compared with Example 3, Comparative Example 6 differs in that potassium dihydrogen phosphate in the compound fertilizer is replaced by phosphorus nitrate and monoammonium phosphate, and potassium nitrate is replaced by potassium sulfate. The yield per mu and the soluble sugar content are both lower than those in Example 3, indicating that the inorganic salts used in the present invention can be combined with other components to better improve the yield and quality of lettuce.

[0115] Compared with Example 3, Comparative Example 7 differs in that potassium dihydrogen phosphate in the compound fertilizer is replaced by phosphorus nitrate and monoammonium phosphate, potassium nitrate is replaced by potassium sulfate, no seaweed extract is added, the microbial powder is freeze-dried powder of Bacillus subtilis, and the trace elements zinc, iron, manganese and boron are not chelated with fulvic acid. The yield per mu and the soluble sugar content are significantly lower than those in Example 3, and lower than those in Comparative Examples 1-6.

[0116] Compared with Example 3, Comparative Example 8 differs in that the preparation method of the compound fertilizer does not perform step S4. The yield per mu and the soluble sugar content of lettuce grown using the compound fertilizer prepared by the method are significantly lower than those in Example 3, indicating that the compound fertilizer prepared by the preparation method of the present invention can better improve the yield and quality of lettuce.

[0117] It can be seen from the planting statistical results of the embodiments and comparative examples that the water-soluble seaweed compound fertilizer provided by the present invention has the effect of increasing the yield and quality of lettuce growth.

[0118] Application Example 2

[0119] The test site is located in a plantation in Qinyantai City, Shandong Province, and the sweet potato variety planted is Yanshu No. 25. 10 plots were randomly divided, and plots of the same size were selected. The compound fertilizers made by Examples 1-3 and Comparative Examples 1-7 were applied to different plots respectively. The fertilizer usage of all test groups was the same, and they were all applied once as base fertilizers, and no topdressing was applied during the growth period. The fertilizer application rate was 15kg / mu, and root irrigation was used for fertilization. Except for fertilization management, other management was the same in each plot. When the sweet potatoes were harvested, the sweet potatoes in each plot were weighed and measured, and the average per mu yield was calculated. The test results are shown in Table 2.

[0120] Table 2 Effects on tobacco and potato yields

[0121] Yield (kg / mu) Example 1 4629.7 Example 2 4776.3 Example 3 4467.5 Comparative Example 1 3923.2 Comparative Example 2 4120.3 Comparative Example 3 4268.4 Comparative Example 4 4371.6 Comparative Example 5 3589.7 Comparative Example 6 4395.1 Comparative Example 7 3237.2 Comparative Example 8 3785.5

[0122] It can be seen from Table 2 that the water-soluble seaweed compound fertilizer provided by Examples 1-3 of the present invention can significantly increase tobacco and potato yields, and Example 2 has the highest per-acre yield.

[0123] Compared with Example 3, the yield of tobacco and potato per mu in Comparative Examples 1-8 is lower than that in Examples 1-3, indicating that the water-soluble seaweed compound fertilizer provided by the present invention can increase the yield of tobacco and potato planting and has a yield-increasing effect on the growth of tobacco and potato.

[0124] In summary, the water-soluble seaweed compound fertilizer provided by the present invention has the effects of increasing the yield and quantity of crops and improving varieties, and has good application prospects.

[0125] Although the embodiments of the present description have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present description, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A water-soluble seaweed compound fertilizer, characterized in that: The invention comprises the following raw materials in parts by weight: 15-30 parts of urea, 15-30 parts of potassium dihydrogen phosphate, 15-30 parts of potassium nitrate, 5-35 parts of seaweed extract, 1-5 parts of microbial powder and 0.5-5 parts of trace elements, wherein the trace elements comprise fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron, and the weight ratio of the fulvic acid chelated zinc, fulvic acid chelated iron, fulvic acid chelated manganese and fulvic acid chelated boron is 1-2:1-2:1-2:1-2; the preparation method of the seaweed extract comprises the following steps: S1, mixing and crushing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1:1:1, adding 7 times volume of water to dissolve and disperse, and obtaining a dispersion; S2, adding compound enzyme 1 to the above dispersion for enzymolysis, and controlling the temperature to 500℃; 40°C, enzymatic reaction for 2.5h, the composite enzyme 1 is composed of amylase, sucrase, cellulase, pectinase and neutral protease, and the addition amounts of amylase, sucrase, cellulase, pectinase and neutral protease in the composite enzyme are 1000U / g, 800U / g, 1200U / g, 1000U / g and 500U / g respectively, and filtered to obtain an enzymatic solution; S3, concentrating the above enzymatic solution, freeze-drying the concentrate to obtain the seaweed extract; the microbial powder is a composite microbial powder, and the composite microbial powder includes Bacillus subtilis, Coraline Nocardia, Bacillus licheniformis and Streptomyces jingyangensis in a weight ratio of 2:1:1:1, and the effective viable bacterial count of each bacteria in the composite microbial powder is ≥5×10 9 cfu / g; the composite microbial powder is a pyrite-based composite microbial powder, and the preparation method of the pyrite-based composite microbial powder is: mixing pyrite and composite microorganisms, and drying to obtain a pyrite-based composite microbial powder loaded with a composite bacterial agent; the effective viable count of the microbial powder is ≥25×10 9 cfu / g.

2. The method for preparing the water-soluble seaweed compound fertilizer according to claim 1, characterized in that: The following steps are involved: S1, feeding urea into the first tank of the high tower reactor and stirring and dissolving at high speed, feeding potassium dihydrogen phosphate and potassium nitrate into the second tank and stirring and dissolving at high speed, feeding seaweed extract and trace elements into the third tank and stirring and dissolving; S2, feeding the materials in the first tank into the second tank and stirring and mixing, and then feeding into the third tank and stirring and mixing; S3, feeding the mixed materials in the third tank into a granulator for granulation, cooling by air cooling, sieving, and rapid freezing; S4, mixing microbial powder and seaweed enzymatic hydrolyzate, and spraying them onto the surface of the frozen particles in S3 to obtain a water-soluble seaweed compound fertilizer; the S4 The method for preparing a seaweed hydrolysate comprises the following steps: S1, mixing and crushing Ascophyllum nodosum, Sargassum and Laminaria japonica in a mass ratio of 1-3:1-3:1-3, and adding 5-15 times volume of water to dissolve and disperse to obtain a dispersion; S2, adding a composite enzyme 2 to the dispersion for enzymatic treatment, wherein the composite enzyme 2 consists of saccharifying enzyme, cellulase and pectinase, and the added amounts of saccharifying enzyme, cellulase and pectinase in the composite enzyme 2 are 800-1000U / g, 1000-1500U / g and 800-1500U / g respectively, filtering to obtain the seaweed hydrolysate.

3. Use of the water-soluble seaweed compound fertilizer according to claim 1 or the water-soluble seaweed compound fertilizer prepared by the preparation method according to claim 2 in crop planting.