Nutrient retention agent as well as preparation method and application thereof

Abstract

The invention provides a nutrient retention agent as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: preparing the modified composite powder, forming the retention carrier, preparing the biological source inhibitor, preparing the synergistic liquid, preparing the regulation and control substrate, spraying the retention carrier for three times in a fluidized bed, and drying to obtain the nutrient retention agent. The invention also provides a nutrient retention agent and an application of the nutrient retention agent in a compound fertilizer. According to the nutrient retention agent provided by the invention, a regulation and control matrix is constructed through sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite, the soil adaptation range is wide, the effect attenuation rate in different soils is low, the production and use processes are simplified, and the popularization threshold is reduced; through the layered coating design, the activity of nutrients such as nitrogen in the fertilizer is effectively retained, the loss of a large amount of nutrients is effectively avoided, and soil nitrification can be effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of soil improvement, specifically to a nutrient retention agent, its preparation method, and its application. Background Technology

[0002] Nutrient conservation and plant growth have always been important research areas in agriculture. In recent years, increased rainfall in many parts of my country has led to greater fertilizer leaching losses, resulting in significant nutrient deficiency in crops during the later stages of growth, especially in sandy soils. How to efficiently improve the soil environment, reduce soil nutrient loss, and promote crop growth has become an urgent problem to be solved.

[0003] While existing nutrient retention agents have achieved the basic function of controlling soil nutrient loss at the physical and chemical levels, they still have significant technical limitations: First, the components have single functions and insufficient synergy, failing to form a better synergistic effect; second, they have narrow soil adaptability, lacking a targeted regulatory mechanism for acidic or alkaline soils, and their effectiveness is greatly reduced in extreme pH soils; third, nutrient release lacks environmental adaptability, failing to match the differences in nutrient requirements of crops at different growth stages, easily leading to nutrient excess in the early stage or nutrient deficiency in the later stage; fourth, the bio-enhancing components have weak targeting, and their promoting effect on root growth is limited to the basic level, without being combined with the regulation of the crop rhizosphere microecological environment.

[0004] Therefore, it is necessary to design a nutrient storage agent that integrates carrier, inhibitor, synergist and regulator to achieve multiple functions such as precise storage, on-demand release, targeted synergistic effect and broad-spectrum compatibility, and solve the core problems of existing nutrient storage agents. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a nutrient retention agent, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution: On one hand, the present invention provides a method for preparing a nutrient retention agent, comprising the following steps: S1. Mix volcanic silica and montmorillonite in proportion, then add KH-550 silane coupling agent and deionized water, heat and stir to react, dry and pulverize to obtain modified composite powder. S2. Dissolve potassium aluminum sulfate and diammonium hydrogen phosphate in deionized water to prepare a solution, and spray the solution onto the surface of the modified composite powder prepared in S1 using a spray drying method to form a storage carrier. S3. Weigh allicin, ferulic acid, and coumarin according to the proportion, add deionized water, then add chitosan powder, disperse by ultrasonication, add β-cyclodextrin and disperse by ultrasonication a second time, dry by vacuum and pulverize the obtained solid to obtain a bio-derived inhibitor. S4. Mix plant-derived protein hydrolysate with yeast metabolite, add γ-polyglutamic acid aqueous solution and polyaspartic acid aqueous solution, stir evenly, add plant root growth-promoting bacteria solution, ferment, centrifuge and concentrate to obtain synergistic solution. S5. Mix starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder in proportion, add deionized water and mix, then ultrasonically disperse and sieve to obtain the control matrix. S6. The nutrient storage carrier prepared in S2 is sprayed three times in a fluidized bed: first, the biological inhibitor prepared in S3 is sprayed, then the synergistic liquid prepared in S4 is sprayed, and finally the regulatory matrix prepared in S5 is sprayed. After drying, the nutrient storage agent is obtained.

[0007] Preferably, in step S1, volcanic silica and montmorillonite are mixed at a mass ratio of 1:1, and the amount of KH-550 silane coupling agent added is 2.0% of the total mass of the mixture of volcanic silica and montmorillonite; the mass of deionized water added is 1.2 times that of volcanic silica, montmorillonite and KH-550 silane coupling agent; the heating temperature is 65℃-75℃, the stirring reaction time is 2-3h; the drying temperature is 80℃, and the drying time is 2h.

[0008] Preferably, in step S2, potassium aluminum sulfate and diammonium hydrogen phosphate are dissolved in deionized water at a mass ratio of 1:1 to prepare a 15% mixed solution; the specific parameters for spray drying are: liquid inlet flow rate of 3 mL / min, spray rate of 4 mL / min, air inlet temperature of 150℃-160℃, and air outlet temperature of 70℃-80℃; the particle size of the storage carrier is controlled within the range of 10-15 μm.

[0009] Preferably, in step S3, the mass ratio of allicin, ferulic acid, and coumarin is (0.8-1.2):(0.8-1.0):(0.5-0.7); deionized water is added at a mass ratio of 1:3; the mass ratio of allicin to chitosan is 1:(0.3-0.5); the concentration of β-cyclodextrin is 12%, and the mass ratio of allicin to β-cyclodextrin is 1:(0.7-0.9); the power of the first and second ultrasonic dispersions is 250W, and the time is 13-17 min; the vacuum drying temperature is 45℃-55℃, and the drying time is 2-3 h; the particle size of the obtained inhibitor is controlled within the range of 5-10 μm.

[0010] Preferably, in step S4, the concentration of plant-derived protein hydrolysate is 100 g / L, and the mass ratio of plant-derived protein hydrolysate to yeast metabolite is 1:1.2; the concentrations of γ-polyglutamic acid aqueous solution and polyaspartic acid aqueous solution are both 5% aqueous solutions, and they are mixed at a mass ratio of 6:5.

[0011] Preferably, in step S4, the volume of the plant root growth-promoting bacteria solution added is 5%; the plant root growth-promoting bacteria solution includes Bacillus subtilis and Bacillus amyloliquefaciens, and the bacterial concentration is 1×10⁻⁶. 9 The concentration ratio of Bacillus subtilis to Bacillus amyloliquefaciens was 1:1; the fermentation temperature was 25℃-35℃, and the fermentation time was 11-13h; the centrifugation concentration speed was 3000-4000r / min, and the centrifugation time was 15min.

[0012] Preferably, in step S5, starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder are mixed at a mass ratio of 1:(0.7-0.8):(0.4-0.6):(0.8-1.2); deionized water is added at a mass ratio of 1:0.8 and mixed; the ultrasonic dispersion power is 250W and the ultrasonic time is 25min; the particle size of the resulting control matrix is ​​controlled within 1-5μm.

[0013] Preferably, the specific parameters for step S6 are as follows: the first spraying air temperature is 50°C, the spraying pressure is 0.45 MPa, and the feeding rate is 3 mL / min; the second spraying temperature is raised to 60°C, the spraying pressure is 0.4 MPa, and the feeding rate is 3 mL / min; the third spraying temperature is raised to 65°C, the spraying pressure is 0.45 MPa, and the feeding rate is 5 mL / min; the drying temperature is 50°C, and the drying time is 3 hours.

[0014] Secondly, the present invention also provides a nutrient retention agent, which is prepared by the above-mentioned nutrient retention agent preparation method; the nutrient retention agent contains the following components by mass percentage: 43%-47% retention carrier, 22%-24% bio-derived inhibitor, 19%-21% synergistic solution, and 12%-14% regulatory matrix.

[0015] Thirdly, the present invention also provides an application of a nutrient retention agent in compound fertilizers.

[0016] The yeast metabolites described in this invention are the metabolites of the recombinant yeast strain (strain number SyBE_Sc118060, exogenous gene combination BDC263crtW-AspcrtZ) described in Chinese invention patent ZL201610355056.8, and the products include astaxanthin.

[0017] The nutrient retention agent, its preparation method, and its application provided by this invention have the following advantages and effects compared to the prior art: (1) The nutrient retention agent provided by the present invention uses sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite to construct a regulatory matrix, which is suitable for a wide range of soils, has a low effect decay rate in different soils, simplifies the production and use process, and lowers the promotion threshold. (2) The nutrient retention agent provided by the present invention effectively retains the activity of nutrients such as nitrogen in fertilizer through a layered coating design, effectively avoids the loss of nutrients in large quantities, and can effectively inhibit soil nitrification. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 A method for preparing a nutrient retention agent includes the following steps: S1. Mix volcanic silica and montmorillonite in a mass ratio of 1:1, add 2.0% of KH-550 silane coupling agent by total mass, add 1.2 times the mass of deionized water, heat and stir at 70°C for 2.5 h, dry at 80°C for 2 h, and then pulverize to obtain modified composite powder. S2. Dissolve potassium aluminum sulfate and diammonium hydrogen phosphate in deionized water at a mass ratio of 1:1 to prepare a 15% mixed solution. Spray the solution onto the surface of the modified composite powder prepared in S1 using a spray drying method. The liquid inlet flow rate is 3 mL / min, the spray rate is 4 mL / min, the inlet air temperature is 155℃, and the outlet air temperature is 75℃ to form a storage carrier with a particle size range of 10-15 μm. S3. Weigh allicin, ferulic acid, and coumarin in a mass ratio of 1:0.9:0.6, add deionized water in a mass ratio of 1:3, then add chitosan powder (mass ratio of allicin to chitosan is 1:0.4), ultrasonically disperse at 250W for 15 min, then add 12% β-cyclodextrin (mass ratio of allicin to β-cyclodextrin is 1:0.8), perform a second ultrasonic dispersion at 250W for 15 min, vacuum dry at 50℃ for 2.5 h, and then pulverize the resulting solid to obtain a bio-derived inhibitor with a particle size range of 5-10 μm. S4. Mix plant-derived protein hydrolysate and yeast metabolite at a mass ratio of 1:1.2. Add a 5% γ-polyglutamic acid aqueous solution and a 5% polyaspartic acid aqueous solution mixed at a volume ratio of 6:5. After stirring evenly, add a plant root-promoting bacteria solution accounting for 5% of the volume of the mixed solution. The plant root-promoting bacteria solution includes Bacillus subtilis and Bacillus amyloliquefaciens at a concentration ratio of 1:1, with a bacterial concentration of 1×10⁻⁶. 9 The synergistic solution was prepared by fermenting at 30℃ for 12 hours with CFU / mL and then centrifuging at 3500r / min for 15 minutes. S5. Mix starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder in a mass ratio of 1:0.7:0.5:1, then add deionized water in a mass ratio of 1:0.8 and mix. After ultrasonic dispersion at 250W for 25 minutes, sieve the mixture to control the particle size of the resulting control matrix within 1-5μm. S6. The nutrient storage carrier prepared in S2 is sprayed three times in a fluidized bed: the first spraying is carried out at an inlet air temperature of 50℃, a spraying pressure of 0.45MPa, and a feed rate of 3mL / min, spraying the bio-based inhibitor prepared in S3; the second spraying is carried out at a temperature of 60℃, a spraying pressure of 0.4MPa, and a feed rate of 3mL / min, spraying the synergistic liquid prepared in S4; the third spraying is carried out at a temperature of 65℃, a spraying pressure of 0.45MPa, and a feed rate of 5mL / min, spraying the regulating matrix prepared in S5; finally, the nutrient storage agent is obtained by drying at 50℃ for 3h.

[0020] Example 2 A method for preparing a nutrient retention agent includes the following steps: S1. Mix volcanic silica and montmorillonite in a mass ratio of 1:1, add 2.0% of KH-550 silane coupling agent by mass, add 1.2 times the mass of deionized water, heat and stir at 65°C for 2 hours, dry at 80°C for 2 hours, and then pulverize to obtain modified composite powder. S2. Dissolve potassium aluminum sulfate and diammonium hydrogen phosphate in deionized water at a mass ratio of 1:1 to prepare a 15% mixed solution. Spray the solution onto the surface of the modified composite powder prepared in S1 using a spray drying method. The liquid inlet flow rate is 3 mL / min, the spray rate is 4 mL / min, the inlet air temperature is 150℃, and the outlet air temperature is 70℃ to form a storage carrier with a particle size range of 10-15 μm. S3. Weigh allicin, ferulic acid, and coumarin in a mass ratio of 0.8:0.8:0.5, add deionized water in a mass ratio of 1:3, then add chitosan powder (mass ratio of allicin to chitosan is 1:0.3), ultrasonically disperse at 250W for 15 min, then add 12% β-cyclodextrin (mass ratio of allicin to β-cyclodextrin is 1:0.7), perform a second ultrasonic dispersion at 250W for 13 min, vacuum dry at 45℃ for 2 h, and then pulverize the resulting solid to obtain a bio-derived inhibitor with a particle size range of 5-10 μm. S4. Mix plant-derived protein hydrolysate and yeast metabolite at a mass ratio of 1:1.2. Add a 5% γ-polyglutamic acid aqueous solution and a 5% polyaspartic acid aqueous solution mixed at a volume ratio of 6:5. After stirring evenly, add a plant root-promoting bacteria solution accounting for 5% of the volume of the mixed solution. The plant root-promoting bacteria solution includes Bacillus subtilis and Bacillus amyloliquefaciens at a concentration ratio of 1:1, with a bacterial concentration of 1×10⁻⁶. 9The synergistic solution was prepared by fermenting at 25°C for 11 hours with CFU / mL at 25°C and then centrifuging at 3000r / min for 15 minutes. S5. Mix starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder in a mass ratio of 1:0.7:0.4:0.8, then add deionized water in a mass ratio of 1:0.8 and mix. After ultrasonic dispersion at 250W for 25 minutes, sieve the mixture to control the particle size of the resulting control matrix within 1-5μm. S6. The nutrient storage carrier prepared in S2 is sprayed three times in a fluidized bed: the first spraying is carried out at an inlet air temperature of 50℃, a spraying pressure of 0.45MPa, and a feed rate of 3mL / min, spraying the bio-based inhibitor prepared in S3; the second spraying is carried out at a temperature of 60℃, a spraying pressure of 0.4MPa, and a feed rate of 3mL / min, spraying the synergistic liquid prepared in S4; the third spraying is carried out at a temperature of 65℃, a spraying pressure of 0.45MPa, and a feed rate of 5mL / min, spraying the regulating matrix prepared in S5; finally, the nutrient storage agent is obtained by drying at 50℃ for 3h.

[0021] Example 3 A method for preparing a nutrient retention agent includes the following steps: S1. Mix volcanic silica and montmorillonite in a mass ratio of 1:1, add 2.0% of KH-550 silane coupling agent by total mass, add 1.2 times the mass of deionized water, heat and stir at 75°C for 3 hours, dry at 80°C for 2 hours, and then pulverize to obtain modified composite powder. S2. Dissolve potassium aluminum sulfate and diammonium hydrogen phosphate in deionized water at a mass ratio of 1:1 to prepare a 15% mixed solution. Spray the solution onto the surface of the modified composite powder prepared in S1 using a spray drying method. The liquid inlet flow rate is 3 mL / min, the spray rate is 4 mL / min, the inlet air temperature is 160℃, and the outlet air temperature is 80℃ to form a storage carrier with a particle size range of 10-15 μm. S3. Weigh allicin, ferulic acid, and coumarin in a mass ratio of 1.2:1:0.7, add deionized water in a mass ratio of 1:3, then add chitosan powder (mass ratio of allicin to chitosan is 1:0.5), ultrasonically disperse at 250W for 15 min, then add 12% β-cyclodextrin (mass ratio of allicin to β-cyclodextrin is 1:0.9), perform a second ultrasonic dispersion at 250W for 17 min, vacuum dry at 55℃ for 3 h, and then pulverize the obtained solid to obtain a bio-derived inhibitor with a particle size range of 5-10 μm. S4. Mix plant-derived protein hydrolysate and yeast metabolite at a mass ratio of 1:1.2. Add a 5% γ-polyglutamic acid aqueous solution and a 5% polyaspartic acid aqueous solution mixed at a volume ratio of 6:5. After stirring evenly, add a plant root-promoting bacteria solution accounting for 5% of the volume of the mixed solution. The plant root-promoting bacteria solution includes Bacillus subtilis and Bacillus amyloliquefaciens at a concentration ratio of 1:1, with a bacterial concentration of 1×10⁻⁶. 9 The synergistic solution was prepared by fermenting at 35°C for 13 hours with CFU / mL at 35°C and then centrifuging at 4000r / min for 15 minutes. S5. Mix starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder in a mass ratio of 1:0.8:0.6:1.2, then add deionized water in a mass ratio of 1:0.8 and mix. After ultrasonic dispersion at 250W for 25 minutes, sieve the mixture to control the particle size of the resulting control matrix within 1-5μm. S6. The nutrient storage carrier prepared in S2 is sprayed three times in a fluidized bed: the first spraying is carried out at an inlet air temperature of 50℃, a spraying pressure of 0.45MPa, and a feed rate of 3mL / min, spraying the bio-based inhibitor prepared in S3; the second spraying is carried out at a temperature of 60℃, a spraying pressure of 0.4MPa, and a feed rate of 3mL / min, spraying the synergistic liquid prepared in S4; the third spraying is carried out at a temperature of 65℃, a spraying pressure of 0.45MPa, and a feed rate of 5mL / min, spraying the regulating matrix prepared in S5; finally, the nutrient storage agent is obtained by drying at 50℃ for 3h.

[0022] Comparative Example 1 Based on Example 1, step S2 was omitted, and the modified composite powder was directly used as the storage carrier to prepare the nutrient storage agent.

[0023] Comparative Example 2 Based on Example 1, in step S3, a single allicin with a mass equal to the total mass of the mixture of allicin, ferulic acid, and coumarin in Example 1 is weighed, while the remaining steps remain unchanged, to prepare a nutrient retention agent.

[0024] Comparative Example 3 Based on Example 1, step S4 is omitted, and S6 is performed only twice (i.e., the synergistic liquid obtained in S4 is not sprayed), to prepare a nutrient retention agent.

[0025] The yeast metabolites described in this invention are the metabolites of the recombinant yeast strain (strain number SyBE_Sc118060, exogenous gene combination BDC263crtW-AspcrtZ) described in Chinese invention patent ZL201610355056.8, and the products include astaxanthin.

[0026] Effect test 1. Nitrogen dissolution rate test: The nutrient retention agent and compound fertilizer prepared in the examples and comparative examples were mixed evenly at a mass ratio of 1:8 to obtain 6 samples, each with a total mass of 100g. Six leaching columns were selected, with 2cm of quartz sand laid at the bottom of each column, and 2kg of dry test soil was filled in. The 6 test samples were evenly mixed in the soil at a depth of 10-15cm, and then another 3cm of test soil was laid on top.

[0027] Nutrient leaching under natural rainfall conditions was simulated using the soil leaching method. The leaching column was placed in a constant temperature incubator at 25℃ and 60% humidity. Every 5 days, 50 mL of deionized water was used for uniform leaching, and all leaching liquid was collected and the volume was recorded. The total nitrogen content in the leaching liquid after 5 / 15 / 25 / 35 days was determined by the Kjeldahl method, and the cumulative nitrogen leaching rate was calculated.

[0028] Compound fertilizer selected from Yangfeng Supreme ® 17-17-17 sulfur-based compound fertilizer; the test soil was selected from Duodao District, Jingmen City, Hubei Province, with a pH of 7.7 and a bulk density of 1.39 g / cm³. 3 .

[0029] The test results are shown in Table 1.

[0030] Table 1

[0031] As shown in Table 1, Examples 1-3 have lower nitrogen dissolution rates compared to Comparative Examples 1-3; among the three examples, Example 1 has a relatively smaller nitrogen dissolution rate.

[0032] 2. Nitrification Inhibition Test: Weigh 0.6 g of the nutrient retention agent prepared in the examples and comparative examples respectively, add 30 mL of distilled water, shake until completely dissolved, and obtain 6 portions of nutrient retention agent solution for later use.

[0033] Weigh 21 soil samples (5 g each) and place them in 50 mL Erlenmeyer flasks. Take 6 groups of 3 Erlenmeyer flasks each, for a total of 18 flasks. Add 10 mL of the above 6 nutrient retention solution to each Erlenmeyer flask in each group. Take another 3 Erlenmeyer flasks, each containing 1 sample of soil, and add 10 mL of distilled water as blank controls.

[0034] In each sample group, 1 mol / L dilute hydrochloric acid was added dropwise to one Erlenmeyer flask while stirring rapidly with a glass rod. The pH was measured with a pH meter every 5 minutes of stirring until the pH stabilized at 5.5 ± 0.1. In another Erlenmeyer flask, 1 mol / L sodium hydroxide solution was added dropwise while stirring rapidly with a glass rod. The pH was measured with a pH meter every 5 minutes of stirring until the pH stabilized at 9.0 ± 0.1. No pH adjustment was performed on the third Erlenmeyer flask.

[0035] Add NH to all samples 4+ Add 10 mL of ammonium sulfate solution with a -N content of 25 mg / L and 0.5 mL of sodium chlorate solution with a 2 mol / L concentration. Mix well, seal the bottle, and incubate at 25°C on a shaker for 5 h.

[0036] After cultivation, the solution was filtered through qualitative filter paper, and the filtrate was collected. The NO content in the filtrate was determined using the N-(1-naphthyl)-ethylenediamine spectrophotometric method. 2- -N content.

[0037] The test results are shown in Table 2.

[0038] Table 2

[0039] As shown in Table 2, the NO content of Examples 1-3 was lower than that of Comparative Examples 1-3. 2- The -N content is lower; comparing the three examples, Example 1 has a stronger overall inhibitory effect on soil nitrification.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a nutrient retention agent, characterized by, The method comprises the following steps: S1, mixing the volcanic source silicon dioxide and the montmorillonite in proportion, adding the KH-550 silane coupling agent and the deionized water, heating and stirring to react, drying, and crushing to obtain a modified composite powder; S2, dissolving the potassium aluminum sulfate and the diammonium hydrogen phosphate in the deionized water to obtain a solution, and spraying the solution on the surface of the modified composite powder obtained in S1 by using a spray drying method to form a nutrient storage carrier; S3, weighing the allicin, ferulic acid and coumarin in proportion, adding the deionized water, then adding the chitosan powder, ultrasonic dispersing, adding the β-cyclodextrin and ultrasonic dispersing again, vacuum drying, and crushing the obtained solid to obtain a biological source inhibitor; S4, mixing the plant source protein hydrolysate and the yeast metabolite, adding the γ-polyglutamic acid aqueous solution and the polyaspartic acid aqueous solution, stirring uniformly, and adding a plant root system growth promoting bacteria solution, and then centrifuging and concentrating after fermentation to obtain a synergistic liquid; S5, mixing the starch acrylamide, sodium carboxymethyl cellulose, carboxymethyl chitosan and zeolite powder in proportion, adding the deionized water, ultrasonic dispersing, and sieving to obtain a regulation matrix; and S6, spraying the biological source inhibitor obtained in S3, the synergistic liquid obtained in S4 and the regulation matrix obtained in S5 on the nutrient storage carrier obtained in S2 for three times in a fluidized bed, and then drying to obtain a nutrient storage agent.

2. The production method according to claim 1, characterized by, In step S1, the volcanic source silicon dioxide and the montmorillonite are mixed in a mass ratio of 1:1, the amount of the KH-550 silane coupling agent added is 2.0% of the total mass of the mixture of the volcanic source silicon dioxide and the montmorillonite, the mass of the deionized water added is 1.2 times that of the volcanic source silicon dioxide, the montmorillonite and the KH-550 silane coupling agent, the heating temperature is 65-75 DEG C, the stirring reaction time is 2-3 h, and the drying temperature is 80 DEG C and the drying time is 2 h.

3. The production method according to claim 1, characterized by, In step S2, the potassium aluminum sulfate and the diammonium hydrogen phosphate are dissolved in the deionized water in a mass ratio of 1:1 to obtain a 15% mixed solution, and the spray drying parameters are as follows: liquid inlet flow rate 3 mL / min, spray rate 4 mL / min, air inlet temperature 150-160 DEG C, and air outlet temperature 70-80 DEG C.

4. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of the allicin, the ferulic acid and the coumarin is (0.8-1.2):(0.8-1.0):(0.5-0.7), the deionized water is added in a mass ratio of 1:3, the mass ratio of the allicin to the chitosan is 1:(0.3-0.5), the concentration of the β-cyclodextrin is 12%, the mass ratio of the allicin to the β-cyclodextrin is 1:(0.7-0.9), the power of the first ultrasonic dispersion and the second ultrasonic dispersion is 250 W, and the time is 13-17 min, and the vacuum drying temperature is 45-55 DEG C and the drying time is 2-3 h.

5. The production method according to claim 1, characterized by, In step S4, the concentration of the plant-derived protein hydrolysate is 100 g / L, the mass ratio of the plant-derived protein hydrolysate to the yeast metabolite is 1:1.2; the concentrations of the aqueous γ-polyglutamic acid solution and the aqueous polyaspartic acid solution are both 5% aqueous solution, and they are mixed at a mass ratio of 6:5; the volume of the plant root growth-promoting bacteria solution added is 5%; the plant root growth-promoting bacteria solution comprises Bacillus subtilis and Bacillus amyloliquefaciens, and the concentration of the bacterial solution is 1×10 9 CFU / mL, the concentration ratio of Bacillus subtilis to Bacillus amyloliquefaciens is 1:1; the fermentation temperature is 25-35°C, the fermentation time is 11-13 h; the centrifugal concentration rotation speed is 3000-4000 r / min, and the centrifugal time is 15 min.

6. The production method according to claim 5, characterized by, The yeast metabolite comprises astaxanthin.

7. The preparation method according to claim 1, characterized in that, In step S5, the starch acrylamide, the sodium carboxymethyl cellulose, the carboxymethyl chitosan and the zeolite powder are mixed in a mass ratio of 1:(0.7-0.8):(0.4-0.6):(0.8-1.2); the deionized water is added in a mass ratio of 1:0.8; the ultrasonic dispersion power is 250 W, and the ultrasonic time is 25 min.

8. The method of claim 1, wherein, In step S6, the specific parameters are as follows: in the first spraying, the inlet air temperature is 50 ℃, the spraying pressure is 0.45 MPa, and the feeding speed is 3 mL / min; in the second spraying, the temperature is increased to 60 ℃, the spraying pressure is 0.4 MPa, and the feeding speed is 3 mL / min; in the third spraying, the temperature is increased to 65 ℃, the spraying pressure is 0.45 MPa, and the feeding speed is 5 mL / min; the drying temperature is 50 ℃, and the drying time is 3 h. The nutrient preservation agent is prepared by the preparation method of any one of claims 1-8, and contains the following components in a mass ratio: a preservation carrier 43%-47%, a biological inhibitor 22%-24%, a synergistic liquid 19%-21%, and a regulation matrix 12%-14%.

9. A nutrient conserving agent, characterized by, 10. Application of the nutrient preservation agent of claim 9 in a compound fertilizer. ​

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