A water-soluble fertilizer based on pollen polysaccharide and a preparation method thereof

Abstract

The present application relates to the technical field of fertilizer, and proposes a water-soluble fertilizer based on pollen polysaccharide and a preparation method thereof.According to 100% by mass, the water-soluble fertilizer comprises 14%-40% of chemical fertilizer, 6%-10% of plant protein-based pollen polysaccharide temperature-sensitive hydrogel, 0.1%-0.5% of chlorogenic acid, 1%-5% of humic acid, and the balance of water.The pollen polysaccharide is wrapped with plant protein to form a temperature-sensitive hydrogel, and the pollen polysaccharide is separated from inorganic salts in the water-soluble fertilizer;then the carboxyl and multiple hydroxyl groups in the chlorogenic acid molecules form a stronger hydrogen bond network and electrostatic interaction with the pollen polysaccharide and plant protein, significantly improving the stability and uniform dispersibility of the hydrogel system.Combination of the two improves the flowability of the fertilizer, avoids stratification, improves the system consistency during spraying or application, and improves the fertilizer efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fertilizers, in particular to a water-soluble fertilizer based on pollen polysaccharide and a preparation method thereof. BACKGROUND

[0002] With the increasing demand for efficient and environmentally friendly fertilizers in modern agriculture, water-soluble fertilizers have become a research hotspot due to their advantages such as rapid absorption and precise fertilization. Water-soluble fertilizers can be used for irrigation, foliar spraying, soilless culture, seed soaking, and other purposes after dilution, which can improve the utilization rate of fertilizers and reduce resource waste and environmental pollution.

[0003] However, existing water-soluble fertilizers still have some technical bottlenecks, such as uneven nutrient release, single functionality, and insufficient solubility. Pollen polysaccharide, as a natural plant extract, has excellent biological activity and can promote plant growth, enhance stress resistance, and improve soil microenvironment. Therefore, the combination of pollen polysaccharide and water-soluble fertilizer can solve the problem of single functionality of water-soluble fertilizer.

[0004] However, due to the complex molecular structure of pollen polysaccharide, when directly combined with water-soluble fertilizer, inorganic salts in water-soluble fertilizer will have incompatibility problems with pollen polysaccharide, resulting in precipitation or stratification after mixing, affecting the stability and application effect of the fertilizer. SUMMARY

[0005] Therefore, in order to overcome the compatibility barrier between pollen polysaccharide and traditional water-soluble fertilizer, the present application provides a water-soluble fertilizer based on pollen polysaccharide and a preparation method thereof.

[0006] The technical solution of the present application is as follows: On the one hand, the present application provides a water-soluble fertilizer based on pollen polysaccharide, which comprises, by mass percentage 100%, 14% to 40% of chemical fertilizer, 6% to 10% of pollen polysaccharide temperature-sensitive hydrogel based on plant protein, 0.1% to 0.5% of chlorogenic acid, 1% to 5% of humic acid, and the balance of water.

[0007] The pollen polysaccharide is wrapped with plant protein to form a temperature-sensitive hydrogel, which isolates the inorganic salts in the water-soluble fertilizer from the pollen polysaccharide, effectively solving the incompatibility problem. The carboxyl group (-COOH) and multiple hydroxyl groups (-OH) in the chlorogenic acid molecule form a stronger hydrogen bond network and electrostatic interaction with pollen polysaccharide and plant protein, significantly improving the stability and uniform dispersibility of the hydrogel system. The combination of the two can improve the flowability of the fertilizer, avoid stratification, and improve the consistency of the system during spraying or application. In addition, the temperature-sensitive release mechanism of the temperature-sensitive hydrogel can improve the nutrient utilization efficiency of the fertilizer during the vigorous growth period of crops under high temperature and strong light, and realize on-demand release.

[0008] On the basis of the above technical solutions, preferably, the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is coupled with gallic acid or phytic acid.

[0009] The present application couples gallic acid or phytic acid on the plant protein-based pollen polysaccharide temperature-sensitive hydrogel, which can improve the film-forming property of water-soluble fertilizer, and has a certain rainwater scouring resistance after being sprayed on the plant leaf surface.

[0010] On the basis of the above technical solutions, preferably, the preparation method of the plant protein-based pollen polysaccharide temperature-sensitive hydrogel comprises the following steps:

[0011] S1, plant protein is added to water, the pH is adjusted to 7-8, and stirring is performed until the protein is dispersed and dissolved to obtain a protein solution;

[0012] S2, pollen polysaccharide is added to the protein solution, and uniform dispersion is continued, and then gallic acid or phytic acid is added, and the temperature is increased to 50-60 DEG C, and the reaction is performed for 1-2 h;

[0013] S3, after the reaction is completed, the reaction solution is cooled to 20-30 DEG C, a beta-glycerophosphate sodium solution (aqueous solution) is slowly added, and stirring is uniformly performed, and then the plant protein-embedded pollen polysaccharide hydrogel is obtained by being placed in a 4 DEG C environment.

[0014] On the basis of the above technical solutions, preferably, sorbitol is added to the protein solution, and after sufficient stirring and dissolution, the pollen polysaccharide is added.

[0015] The addition of sorbitol can increase the stability of the water-soluble fertilizer under long-term storage, the hydroxyl groups of sorbitol can form a large number of hydrogen bonds and weak van der Waals forces with the amino groups, hydroxyl groups and other groups of protein and polysaccharide molecules, the intermolecular interaction force is enhanced, the gel network is more dense and stable, and especially under high-temperature storage or external disturbance, the gel network is not easy to disintegrate.

[0016] On the basis of the above technical solutions, preferably, the amount of sorbitol is 10%-15% of the mass of the protein solution.

[0017] On the basis of the above technical solutions, preferably, in step S1, the mass ratio of the plant protein to water is 1:10-20.

[0018] On the basis of the above technical solutions, preferably, in step S2, the mass ratio of the plant protein to pollen polysaccharide to gallic acid is 10:2-3:0.1-0.3, and the mass ratio of the plant protein to pollen polysaccharide to phytic acid is 10:2-3:0.4-0.6.

[0019] On the basis of the above technical solutions, preferably, in step S3, the mass concentration of the beta-glycerophosphate sodium solution is 8%-12%, and the amount is 10%-15% of the volume of the reaction solution.

[0020] Preferably, the chemical fertilizer is one or more of nitrogen fertilizer, potassium fertilizer and phosphorus fertilizer; and the plant protein is selected from soybean protein.

[0021] In another aspect, the application also provides a preparation method of the water-soluble fertilizer based on pollen polysaccharide, comprising the following steps:

[0022] The chemical fertilizer is added into water and stirred until dissolved, then humic acid is added, and after stirring uniformly, the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is added, and high-speed shearing is performed at 10,000 rpm for 5-10 min to form a microparticle (D50≤10 μm) gel form, then a chlorogenic acid alcohol solution is added and water is supplemented, and after stirring uniformly, the pH value is adjusted to 6.5-7.5.

[0023] The water-soluble fertilizer based on pollen polysaccharide and the preparation method thereof have the following beneficial effects compared with the prior art:

[0024] In the application, the pollen polysaccharide is wrapped with plant protein to form a temperature-sensitive hydrogel, and the pollen polysaccharide is isolated from inorganic salts in the water-soluble fertilizer; the carboxyl and multiple hydroxyl groups in the chlorogenic acid molecule form a stronger hydrogen bond network and electrostatic interaction with the pollen polysaccharide and the plant protein, thereby significantly improving the stability and uniform dispersibility of the hydrogel system. The combination of the two can improve the flowability of the fertilizer, avoid stratification, and improve the consistency of the system during spraying or application. In addition, the temperature-sensitive release mechanism of the temperature-sensitive hydrogel can improve the nutrient utilization efficiency of the fertilizer during the vigorous growth period of crops under high temperature and strong light, and realize on-demand release.

[0025] In the application, gallic acid or phytic acid is coupled on the plant protein-based pollen polysaccharide temperature-sensitive hydrogel, which can improve the film-forming property of the water-soluble fertilizer, and after being sprayed onto the plant leaves, the water-soluble fertilizer has a certain rainwater washing resistance.

[0026] The addition of sorbitol can increase the stability of the water-soluble fertilizer during long-term storage. The hydroxyl groups of sorbitol can form a large number of hydrogen bonds and weak van der Waals forces with the amino groups and hydroxyl groups of protein and polysaccharide molecules, thereby increasing the intermolecular interaction force, making the gel network more dense and stable, and preventing the gel from being easily disintegrated under high-temperature storage or external disturbance. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0028] The chlorogenic acid (purity 98%) used in the application is purchased from Shanghai Yuanye Biological Technology Co., Ltd.

[0029] The pollen polysaccharide used in the present application is a self-made product, and the extraction method is as follows: 1. Pretreatment: dry rape pollen is crushed to 100 mesh, then washed with anhydrous ethanol to remove surface impurities and oil; then filtered, and dried. The pollen powder is soaked in pure water according to 1:10 (m / v) to make the pollen swell by absorbing water. 2. Enzymatic hydrolysis: 2% cellulase, 1.5% pectinase and 1% xylanase are added according to the mass of the pollen powder, the pH is adjusted to 5, and the enzymatic hydrolysis is carried out at 50℃ for 8h, and then the enzyme is inactivated by heating in a water bath at 95℃ for 10min. 3. Crude polysaccharide separation: after enzymatic hydrolysis, the temperature is lowered to room temperature, the supernatant is collected by centrifugation, and then concentrated to 1 / 2 under reduced pressure. 4. Crude polysaccharide purification: to the concentrated enzymatic hydrolysate, 80% ethanol is added in a volume ratio of 1:3 (enzymatic hydrolysate: ethanol), mixed uniformly, and then placed at 4℃ overnight. The precipitate is collected by centrifugation, and then washed with a small amount of 95% ethanol and ether in turn. Then the polysaccharide solution is freeze-dried to obtain rape pollen polysaccharide.

[0030] Example 1

[0031] The water-soluble fertilizer based on pollen polysaccharide of the present application, calculated according to 100% by mass, comprises fertilizer (urea and dihydrogen potassium phosphate in a mass ratio of 2:1) 21%, plant protein-based pollen polysaccharide temperature-sensitive hydrogel 9%, chlorogenic acid 0.3%, humic acid 3%, and the balance is water.

[0032] The preparation method of the plant protein-based pollen polysaccharide temperature-sensitive hydrogel comprises the following steps:

[0033] S1, 10g of soybean protein is added to 160g of water, the pH is adjusted to 7, and the protein is stirred to be dispersed and dissolved to obtain a protein solution;

[0034] S2, 2.5g of pollen polysaccharide is added to the protein solution, and the stirring is continued to make it uniformly dispersed, and then the temperature is raised to 55℃, and the reaction is carried out for 1.5h;

[0035] S3, after the reaction is completed, the reaction liquid is cooled to 25℃, and a 10% mass concentration of β-glycerophosphate sodium aqueous solution is slowly added in an amount of 14% of the volume of the reaction liquid, and then stirred uniformly and placed in a 4℃ environment to obtain a plant protein-embedded pollen polysaccharide hydrogel.

[0036] The preparation method of the above-mentioned water-soluble fertilizer comprises the following steps: first, the fertilizer is added to water and stirred to dissolve, then the humic acid is added, and then the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is added, and the mixture is sheared at a high speed of 10000 rpm for 10min to form a microparticle gel, then the chlorogenic acid is added and the water is supplemented, and the mixture is stirred uniformly, and the pH value is adjusted to 6.5.

[0037] Example 2

[0038] Example 2 adds the following to Example 1:

[0039] A plant protein-based pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid, the preparation method comprising the following steps:

[0040] S1 is the same as in Example 1.

[0041] S2, 2.5g of pollen polysaccharide is added to the protein solution, and stirring is continued to uniformly disperse, and then 0.2g of gallic acid is added, and the temperature is raised to 55°C, and the reaction is carried out for 1.5h.

[0042] S3 is the same as in Example 1.

[0043] Example 3

[0044] Example 3 adds the following to Example 2:

[0045] A plant protein-based pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid, the preparation method comprising the following steps:

[0046] S1 is the same as in Example 1.

[0047] S2, 13% of sorbitol by mass of the protein solution is added to the protein solution, and after being fully stirred and dissolved, 2.5g of pollen polysaccharide is added, and stirring is continued to uniformly disperse, and then 0.2g of gallic acid is added, and the temperature is raised to 55°C, and the reaction is carried out for 1.5h.

[0048] S3 is the same as in Example 1.

[0049] Example 4

[0050] This example is based on a water-soluble fertilizer of pollen polysaccharide, which comprises, in terms of mass percentage 100%, 14% of chemical fertilizer (urea and potassium dihydrogen phosphate in a mass ratio of 2:1), 7% of a plant protein-based pollen polysaccharide temperature-sensitive hydrogel, 0.1% of chlorogenic acid, 2% of humic acid, and the balance being water.

[0051] A plant protein-based pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid or phytic acid, the preparation method comprising the following steps:

[0052] S1, 10g of soybean protein is added to 100g of water, the pH is adjusted to 7, and stirring is carried out until the protein is dispersed and dissolved to obtain a protein solution;

[0053] S2, 10% of sorbitol by mass of the protein solution is added to the protein solution, and after being fully stirred and dissolved, 2g of pollen polysaccharide is added, and stirring is continued to uniformly disperse, and then 0.4g of phytic acid is added, and the temperature is raised to 50°C, and the reaction is carried out for 1h;

[0054] S3, after the reaction, the reaction solution is cooled to 25℃, 10% of the reaction solution by volume of 8% mass concentration of β-glycerophosphate sodium solution is slowly added, and after stirring, it is placed in a 4℃ environment to obtain the plant protein-embedded pollen polysaccharide hydrogel.

[0055] The preparation method of the water-soluble fertilizer based on pollen polysaccharide includes the following steps:

[0056] The fertilizer is added to water and stirred until dissolved, then humic acid is added, and after stirring, the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is added, and high-speed shearing at 10000 rpm for 5 min is performed to form a microparticle gel, then chlorogenic acid is added and water is added to make up the volume, and after stirring, the pH value is adjusted to 6.5.

[0057] Example 5

[0058] The water-soluble fertilizer based on pollen polysaccharide in this example, calculated as 100% by mass, includes 27% fertilizer (urea and potassium dihydrogen phosphate in a mass ratio of 2:1), 8% plant protein-based pollen polysaccharide temperature-sensitive hydrogel, 0.4% chlorogenic acid, 5% humic acid, and the balance is water.

[0059] The preparation method of the plant protein-based pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid or phytic acid includes the following steps:

[0060] S1, 10g of soybean protein is added to 180g of water, the pH is adjusted to 8, and stirring is performed until the protein is dispersed and dissolved to obtain a protein solution;

[0061] S2, 14% of sorbitol by mass of the protein solution is added to the protein solution, and after stirring to dissolve, 2.8g of pollen polysaccharide is added, and stirring is continued to uniformly disperse it, then 0.1g of gallic acid is added, and the temperature is raised to 60℃, and the reaction is carried out for 1.5h;

[0062] S3, after the reaction, the reaction solution is cooled to 30℃, 13% of the reaction solution by volume of 11% mass concentration of β-glycerophosphate sodium solution is slowly added, and after stirring, it is placed in a 4℃ environment to obtain the plant protein-embedded pollen polysaccharide hydrogel.

[0063] The preparation method of the water-soluble fertilizer based on pollen polysaccharide includes the following steps:

[0064] The fertilizer is added to water and stirred until dissolved, then humic acid is added, and after stirring, the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is added, and high-speed shearing at 10000 rpm for 8 min is performed to form a microparticle gel, then chlorogenic acid is added and water is added to make up the volume, and after stirring, the pH value is adjusted to 7.

[0065] Example 6

[0066] The water-soluble fertilizer based on pollen polysaccharide according to the embodiment comprises, calculated according to 100% by mass, 40% of chemical fertilizer (urea and monopotassium phosphate in a mass ratio of 2:1), 8% of pollen polysaccharide temperature-sensitive hydrogel based on plant protein, 0.5% of chlorogenic acid, 4% of humic acid, and the balance of water.

[0067] The preparation method of the pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid or phytic acid based on plant protein comprises the following steps:

[0068] S1, 10g of soybean protein is added to 200g of water, the pH is adjusted to 8, and stirring is performed until the protein is dispersed and dissolved to obtain a protein solution;

[0069] S2, 15% of sorbitol by mass of the protein solution is added to the protein solution, and after being fully stirred and dissolved, 3g of pollen polysaccharide is added, and stirring is continued to uniformly disperse the pollen polysaccharide, and then 0.3g of gallic acid is added, and the temperature is raised to 60°C, and reaction is performed for 2h;

[0070] S3, after the reaction is completed, the reaction solution is cooled to 30°C, 15% of the reaction solution by volume is added to a 12% mass concentration sodium β-glycerophosphate solution, the solution is uniformly stirred, and then the solution is placed in a 4°C environment to obtain a pollen polysaccharide hydrogel embedded with plant protein.

[0071] The preparation method of the water-soluble fertilizer based on pollen polysaccharide comprises the following steps:

[0072] The chemical fertilizer is added to water and stirred until the chemical fertilizer is dissolved, then the humic acid is added, the pollen polysaccharide temperature-sensitive hydrogel based on plant protein is added after the humic acid is uniformly stirred, the solution is sheared at a high speed of 10000 rpm for 10min to form a microparticle gel, then the chlorogenic acid is added and water is added to make up the volume, and the solution is uniformly stirred and the pH value is adjusted to 7.5.

[0073] Embodiment 7

[0074] The water-soluble fertilizer based on pollen polysaccharide according to the embodiment comprises, calculated according to 100% by mass, 40% of chemical fertilizer (urea and monopotassium phosphate in a mass ratio of 2:1), 8% of pollen polysaccharide temperature-sensitive hydrogel based on plant protein, 0.5% of chlorogenic acid, 4% of humic acid, and the balance of water.

[0075] The preparation method of the pollen polysaccharide temperature-sensitive hydrogel coupled with gallic acid or phytic acid based on plant protein comprises the following steps:

[0076] S1, 10g of soybean protein is added to 200g of water, the pH is adjusted to 8, and stirring is performed until the protein is dispersed and dissolved to obtain a protein solution;

[0077] S2, 11% sorbitol of the protein solution mass was added to the protein solution, after fully stirring and dissolving, 2.2 g of pollen polysaccharide was added, and stirring was continued to uniformly disperse, then 0.6 g of phytic acid was added, and the temperature was raised to 60°C, and reacted for 2 h;

[0078] S3, after the reaction was completed, the reaction liquid was cooled to 30°C, 11% of the reaction liquid volume was added, and the mass concentration of the β-glycerophosphate sodium solution was 9%, after stirring, it was placed in a 4°C environment to obtain a plant protein-embedded pollen polysaccharide hydrogel.

[0079] The preparation method of the water-soluble fertilizer based on pollen polysaccharide comprises the following steps:

[0080] The fertilizer was added to water and stirred to dissolve, then humic acid was added, and after stirring, the plant protein-based pollen polysaccharide temperature-sensitive hydrogel was added, and high-speed shearing was performed at 10,000 rpm for 10 min to form a microparticle gel, then chlorogenic acid was added and water was added to make up the volume, and the pH value was adjusted to 7.5.

[0081] Comparative Example 1

[0082] Comparative Example 1 and Example 1, pollen polysaccharide is not prepared into a plant protein-based pollen polysaccharide temperature-sensitive hydrogel state, but is directly added.

[0083] Comparative Example 2

[0084] Comparative Example 2 and Example 1, no chlorogenic acid is added, and the rest is the same.

[0085] Comparative Example 3

[0086] Comparative Example 3 and Example 1, the addition amount of the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is higher than the limited range, specifically 20% of the total weight of the water-soluble fertilizer, and the rest is the same.

[0087] Comparative Example 4

[0088] Comparative Example 4 and Example 1, the addition amount of chlorogenic acid is higher than the limited range, specifically 1.5% of the total weight of the water-soluble fertilizer, and the rest is the same.

[0089] Comparative Example 5

[0090] Comparative Example 5 and Example 2, the amount of gallic acid is higher than the limited range, specifically 1 g, and the rest is the same.

[0091] Comparative Example 6

[0092] Comparative Example 6 and Example 3, the amount of sorbitol is higher than the limited range, specifically 15% of the mass of the protein solution, and the rest is the same.

[0093] Stability test: 1L of water-soluble fertilizer product prepared in the examples and comparative examples was poured into a volumetric flask and placed in a thermostat to test the stability during storage. The test conditions were 25℃ for 90 days and 45℃ for 14 days, respectively. The results are shown in Table 1.

[0094]

[0095] In Example 2, the multi-functional groups of gallic acid or phytic acid can improve the thermal stability of the gel system, so that it is not easy to precipitate and stratify even at a higher temperature of 45℃ for 7-14 days, and the overall fertilizer efficiency and use performance are guaranteed. In Example 3, the addition of sorbitol can interact with protein and polysaccharide molecules, making the gel network more compact and stable, and especially not easy to disintegrate under high temperature storage or external disturbance.

[0096] In Comparative Example 1, the pollen polysaccharide is prone to adverse reactions (such as crystallization and flocculation) with inorganic salts, and the dispersibility and system stability decrease significantly, which is easy to precipitate and stratify during storage, especially at high temperature. In Comparative Example 2, the loss of the intermolecular interaction of chlorogenic acid makes it difficult to strengthen the stability of the colloid network, resulting in a decrease in thermal stability and particle dispersibility, and easy precipitation. In Comparative Example 3, the proportion of temperature-sensitive hydrogel is too high, the system is viscous, and the particles are easy to aggregate and settle, especially at high temperature. In Comparative Example 4, too much chlorogenic acid is complexed with protein and polysaccharide, which can cause chaos in the colloid system, and may cause insoluble precipitation or colloid rupture, which is easy to stratify. In Comparative Example 5, excessive gallic acid can cause local complex precipitation in the system, particle aggregation, and a decrease in dispersibility and transparency, especially at high temperature. In Comparative Example 6, excessive sorbitol can cause a decrease in colloid water, and the network is too dense, even dehydrated and hardened, and the colloid is easy to clump and precipitate at room temperature and high temperature.

[0097] Rain erosion test: 1L of the water-soluble fertilizer of the above examples and comparative examples was prepared and tested for its resistance to erosion. The experimental method was as follows: the water-soluble fertilizer of the examples and comparative examples was diluted 1000 times with water to prepare a foliar fertilizer, and tomato red pigment was added as an indicator at a ratio of 1:100000 (mass ratio), which was sprayed on the leaves of corn, four seasons beans and rice, and 5 leaves were randomly taken from each group. The spraying was stopped when the leaves were completely wet, and the spraying amount (mL) was recorded. After the leaves were naturally dried, the leaves were sprayed with tap water to simulate rain, and the spraying amount was 5 times the spraying amount of the foliar fertilizer. After the leaves were dried, the second time of water spraying was carried out, and the water spraying amount was the same as the first time. After the two times of water spraying, 5 cm of the middle part of each leaf was taken for photography, and the software was used to calculate the dyeing percentage (%). The results are shown in the following table.

[0098]

[0099] From the dyeing ratio in Table 2, it can be seen that after the gel coupling of gallus acid in Example 2, the film-forming property is enhanced, and the rain washing resistance is also improved. Sorbitol mainly enhances the high-temperature and long-term storage stability of the fertilizer, so the rain washing resistance of Example 3 is not significantly different from that of Example 2.

[0100] Comparative Example 1 directly exposes the unembedded pollen polysaccharide, has poor film-forming property, is easily washed away by rain, and has a significantly reduced residual amount. Comparative Example 2 does not add chlorogenic acid, the colloid film network structure is weak, and the washing resistance is reduced. Comparative Example 3 has slightly higher film-forming property than Example 1. Comparative Example 4 has extremely high chlorogenic acid content, which instead leads to brittle film-forming property or uneven film structure, resulting in reduced washing resistance. Comparative Example 5 has excessive gallus acid, which may inhibit the film-forming property, the film structure is too hard or has inclusions, and the residual rate is instead reduced. Comparative Example 6 has increased sorbitol dosage, which is not significantly related to the film-forming property and is not significantly different from Example 3.

[0101] Pot experiment: The water-soluble fertilizers of the examples and comparative examples were diluted 1000 times with water to prepare foliar fertilizers. Cucumbers were used as experimental materials, and 10 replicates were set for each example or comparative example, with 1 cucumber per replicate. The potting soil of the examples and comparative examples was kept consistent, and the cucumbers were sown in mid-April, and fertilization and watering management were performed according to routine operations during growth. During growth, foliar spraying was performed 4 times during the leaf growth period, the flowering period, the fruit setting period, and the middle of the fruit picking period. Each spraying formed uniform mist on the surface of the plant leaves, flowers, and fruits, but no water droplets were formed. During growth, simulated natural rain was performed 3 days after the 2nd-4th foliar spraying, under the same conditions as the rain washing resistance experiment described above. After the fruits were harvested, the number of cucumbers per plant, the length, diameter, and weight of single cucumbers were counted. The relevant experimental data are shown in Table 3.

[0102]

[0103] As shown in Table 3, the number of cucumbers per plant, the weight, length, and diameter of single cucumbers of the examples were higher than those of the comparative examples, among which the spraying effect of Example 3 was the best, followed by Example 2. This is because the gallus acid coupling in Example 2 enhances the rain washing resistance of the leaf film layer, and the fertilizer absorption time is prolonged, so the effect is better than that of Example 1. In Example 3, the sorbitol stabilizes the gel network, and the active ingredients do not decay after storage, so the system stability is higher after multiple spraying, and the number of cucumbers and the weight of single cucumbers are further improved; in addition, the sorbitol improves the colloid dispersibility, and the trace elements are uniformly distributed on the leaf surface, promoting cell division and expansion, and thus improving the diameter of the cucumbers.

[0104] Comparative Example 1 Since polysaccharides are not embedded, the effective component of fertilizer (pollen polysaccharides) is directly exposed to rain erosion and soil environment, a large amount of loss, biological stimulation effect loss, leading to melon less, small, light. In addition, the unembedded pollen polysaccharides are inactivated by reacting with inorganic salts in the fertilizer, and the utilization rate of fertilizer efficiency is seriously decreased.

[0105] Comparative Example 2 Since there is no chlorogenic acid, the colloid network is loose, and the fertilizer film layer is easy to break after simulating rain, the fertilizer retention time is shortened, but it is slightly better than the unembedded system of Comparative Example 1. Comparative Example 2 still has a temperature-sensitive hydrogel basic structure, the water and fertilizer retention capacity is partially retained, and the single melon weight is improved compared with Comparative Example 1.

[0106] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A water-soluble fertilizer based on pollen polysaccharides, characterized in that: The water-soluble fertilizer comprises 14-40% of chemical fertilizer, 6-10% of plant protein-based pollen polysaccharide temperature-sensitive hydrogel, 0.1-0.5% of chlorogenic acid, 1-5% of humic acid, and the balance of water, calculated based on 100% of mass percentage. The preparation method of the plant protein-based pollen polysaccharide temperature-sensitive hydrogel comprises the following steps: S1, plant protein is added into water, the pH is adjusted to 7-8, and the protein is stirred to be dispersed and dissolved to obtain a protein solution; S2, pollen polysaccharide is added into the protein solution, and stirring is continued to uniformly disperse the pollen polysaccharide, then gallic acid or phytic acid is added, the temperature is increased to 50-60 DEG C, and reaction is performed for 1-2 hours; S3, after the reaction is completed, the reaction liquid is cooled to 20-30 DEG C, a β-glycerophosphate sodium solution is slowly added, and the mixture is stirred to be uniform, and then the mixture is placed in a 4 DEG C environment to obtain a plant protein-embedded pollen polysaccharide hydrogel; The preparation method of the pollen polysaccharide-based water-soluble fertilizer comprises the following steps: chemical fertilizer is added into water and stirred to be dissolved, then humic acid is added, the mixture is stirred to be uniform, and then the plant protein-based pollen polysaccharide temperature-sensitive hydrogel is added, high-speed shearing is performed at 10000 rpm for 5-10 minutes to obtain a microparticle gel form, then chlorogenic acid is added, and water is added to make up the volume, the mixture is stirred to be uniform, and the pH value is adjusted to 6.5-7.

5.

2. A water soluble fertilizer based on pollen polysaccharides according to claim 1, characterized by: Sorbitol is added into the protein solution, and the mixture is stirred to be dissolved.

3. A water soluble fertilizer based on pollen polysaccharides according to claim 2, characterized by the fact that: The amount of sorbitol is 10% of the mass of the protein solution.

4. A water soluble fertilizer based on pollen polysaccharides according to claim 1, characterized by: In step S1, the mass ratio of the plant protein to water is 1:10-20.

5. A water soluble fertilizer based on pollen polysaccharides according to claim 1, characterized by: In step S2, the mass ratio of the plant protein to pollen polysaccharide to gallic acid is 10:2-3:0.1-0.

3. The mass ratio of the plant protein to pollen polysaccharide to phytic acid is 10:2-3:0.4-0.

6.

6. A water soluble fertilizer based on pollen polysaccharides according to claim 1, characterized by: In step S3, the mass concentration of the β-glycerophosphate sodium solution is 8%-12%, and the amount of the β-glycerophosphate sodium solution is 10%-15% of the volume of the reaction liquid.

7. A water soluble fertilizer based on pollen polysaccharides according to claim 1, characterized by: The chemical fertilizer is one or more of nitrogen fertilizer, potassium fertilizer and phosphorus fertilizer; and the plant protein is selected from soybean protein.

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