Liquid chemical fertilizer for orange planting and preparation method thereof

Abstract

The invention relates to the technical field of plant planting chemical fertilizers, and discloses a liquid chemical fertilizer for orange planting and a preparation method thereof. The fertilizer is prepared from the following components in parts by weight: 10-15 parts of a compound nitrogen source of calcium nitrate and ammonium sulfate, 5-8 parts of a compound phosphorus source of potassium pyrophosphate and ammonium dihydrogen phosphate, 8-12 parts of a mixed potassium source of potassium citrate and potassium sulfate, 0.1-0.3 part of EDTA-Zn, 1-2 parts of calcium amino acid chelate, 0.3-0.8 part of polyaspartic acid, 0.05-0.1 part of nano silicon dioxide and 1-2 parts of a co-culture of trichoderma harzianum and nitrogen-fixing bacteria. According to the invention, a special nano material and a high-molecular polymer have a synergistic effect, a three-dimensional protection network is constructed, various nutrients are ensured to be kept in a uniformly dispersed state for a long time, a dual-molecular protection mechanism is developed aiming at the characteristic that trace elements are easy to lose efficacy, and the nutrient solution has the advantages that the nutrient solution has good stability, and the nutrient solution has a good application prospect. And oxidation and precipitation are effectively prevented, so that the product can still keep stable components under extreme storage conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plant planting fertilizers, in particular to a liquid fertilizer for orange planting and a preparation method thereof. BACKGROUND

[0002] Citrus is one of the most important economic crops in the world, and its planting has special requirements for fertilizers, including balanced absorption of nitrogen, phosphorus, and potassium, as well as sensitivity to medium and trace elements such as magnesium, zinc, and boron. Traditional fertilization methods mainly use solid fertilizers, but in recent years, liquid fertilizers have gradually gained attention due to their high absorption efficiency and ease of precise application.

[0003] However, existing liquid fertilizer technology still has significant drawbacks, which restrict its promotion in citrus planting: 1) Liquid fertilizers are prone to component separation or precipitation during storage and transportation, leading to uneven nutrient distribution. For example, high concentrations of phosphorus and potassium elements may crystallize and precipitate at low temperatures or after long-term standing, while trace elements such as iron and zinc are easily oxidized or react with other components in the solution, reducing their effectiveness; 2) The pH value of some liquid fertilizers is unstable, and excessive acidity can corrode metal containers, while excessive alkalinity may cause ammonia volatilization. These problems make it difficult to achieve the expected fertilizer effect in actual application; 3) For small-scale farmers, the cost is relatively high, and if artificial leaf spraying is used, the dilution ratio and spraying uniformity need to be strictly controlled, otherwise leaf burn (such as edge scorch) may occur, which is difficult to operate. In addition, liquid fertilizers have strong permeability and may easily penetrate to the deep layer of the root system in sandy soil with rainwater or irrigation water, while in heavy soil, they may be retained on the surface, causing salinization. This sensitivity to soil type and climate conditions increases the technical threshold and risk of fertilization. Therefore, a liquid fertilizer for orange planting and a preparation method thereof are proposed. SUMMARY

[0004] The present application aims to provide a liquid fertilizer for orange planting and a preparation method thereof to solve the problems raised in the background.

[0005] To achieve the above object, the application provides the following technical scheme: A liquid fertilizer for orange planting is prepared from the following components in parts by weight: 10-15 parts of calcium nitrate and ammonium sulfate compound nitrogen source, the ratio of nitrate nitrogen to ammonium nitrogen being 4:1, 5-8 parts of potassium pyrophosphate and ammonium dihydrogen phosphate compound phosphorus source, 8-12 parts of potassium citrate and potassium sulfate mixed potassium source, 0.1-0.3 parts of EDTA-Zn and 1-2 parts of amino acid chelated calcium, 0.3-0.8 parts of polyaspartic acid and 0.05-0.1 parts of nano silicon dioxide, 1-2 parts of co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, 0.05-0.2 parts of chitosan oligosaccharide and 10-20 ppm of brassinolide, and an appropriate amount of pH regulator to stabilize the system at 6.2-6.8, and an appropriate amount of viscosity control agent, the viscosity being 50-80 cP at 25 DEG C.

[0006] As preferred, in the co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, the proportion of viable Trichoderma harzianum is not less than 80%, and the co-culture is subjected to microcapsule embedding treatment to improve environmental stability, and the viscosity control agent is a mixture of xanthan gum and carboxymethyl cellulose, the weight ratio of the two being 1:1-1:2, for synergistically regulating fluidity and nutrient slow-release performance.

[0007] A preparation method of the liquid fertilizer for orange planting as described above, comprising the following specific steps: S1: preparation of a basic nutrient solution: sequentially dissolving potassium pyrophosphate and ammonium dihydrogen phosphate in deionized water at 60-70 DEG C, and adding a preheated calcium nitrate solution to 50 DEG C; S2: intelligent chelation reaction: pre-chelating EDTA-Zn and L-calcium aspartate at pH 5.5, and adding polyaspartic acid and nano silicon dioxide dispersion; S3: integration of biological activity: centrifuging and concentrating the 48-hour co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, and activating the chitosan oligosaccharide-brassinolide solution at 28 DEG C for 2 hours; S4: final adjustment of the system: adopting a three-stage gradient mixing process, and performing membrane filtration and nitrogen filling and packaging.

[0008] As preferred, in S1, the following sub-steps are included: S101: ultrasonic-assisted dissolution; S102: stepwise addition of phosphate and calcium salt, the interval being ≥30 min; S103: real-time monitoring of conductivity change.

[0009] As preferred, in S2, the following sub-steps are included: S201: maintaining a nitrogen-protected environment in the chelation reaction kettle; S202: adopting an online pH automatic control system; S203: plasma treatment before adding nano silicon dioxide.

[0010] As preferred, the nitrogen flow in the step S201 is controlled at 0.8-1.2 L / min, and the oxygen content is <0.5%.

[0011] As preferred, the step S3 comprises the following sub-steps: S301, adding 0.1% trehalose as a protective agent during the strain co-culture; S302, the centrifugation process is controlled at 4°C and the relative centrifugal force is 8000xg; S303, the light intensity in the activation stage is controlled at 2000-3000 lux.

[0012] As preferred, the centrifugation time and the cell concentration in the step S302 satisfy the formula: t=K×(log10N0-log10Nt) wherein K=15 min, N0 is the initial concentration, and Nt is the target concentration.

[0013] As preferred, the step S4 comprises the following sub-steps: S401, the temperature gradient of the three-stage mixing is: 25°C→35°C→28°C; S402, pre-coating 0.1% diatomite filter aid layer before membrane filtration; S403, the inner wall of the packaging container is plated with a nano-silver antibacterial layer.

[0014] As preferred, the thickness of the nano-silver plating layer in the step S403 is 50-80 nm, and the surface roughness Ra is ≤0.2 μm.

[0015] Compared with the prior art, the above technical scheme has the following technical effects: I. The special nano material and high molecular polymer are used to construct a three-dimensional protective network, ensuring that various nutrients remain uniformly dispersed for a long time. A double molecular protection mechanism is developed to prevent oxidation and precipitation, so that the product can still maintain stable composition under extreme storage conditions, greatly improving the actual use effect of the fertilizer. II. The patent can automatically identify and neutralize environmental pH changes through the synergistic effect of multiple buffer pairs, accurately stabilize the solution pH value in the most suitable range for citrus growth, and quickly respond to external interference through the innovative dynamic adjustment mechanism. This design not only ensures the long-term stability of the fertilizer composition, but also significantly reduces the risk of crop damage caused by acid-base imbalance. III. The adaptive viscosity system of the patent enables intelligent adjustment of the physical properties of the product, ensuring both the smoothness of pipeline transportation and the uniformity of leaf surface adhesion, effectively solving the problems of nutrient leaching in sandy soil and salinization in heavy clay soil. The innovative safety controlled-release mechanism can prevent over-fertilization damage, and even if the operation is improper, it can maximize the protection of crop safety. These designs significantly reduce the requirements for application equipment and technology, making the product particularly suitable for small-scale farmers. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0017] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

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

[0019] EMBODIMENT Please refer to Figure 1 The present application provides a technical solution: a liquid fertilizer for orange planting, which is prepared from the following components in parts by weight: 10-15 parts of calcium nitrate and ammonium sulfate complex nitrogen source (the ratio of nitrate nitrogen to ammonium nitrogen is 4:1), 5-8 parts of potassium pyrophosphate and ammonium dihydrogen phosphate complex phosphorus source, 8-12 parts of potassium citrate and potassium sulfate mixed potassium source, 0.1-0.3 parts of EDTA-Zn and 1-2 parts of amino acid chelated calcium, 0.3-0.8 parts of polyaspartic acid and 0.05-0.1 parts of nano silicon dioxide, 1x10 8 CFU / g of Trichoderma harzianum and 1x10 71-2 parts, chitosan oligosaccharide 0.05-0.2 parts, and brassinolide 10-20 ppm, pH regulator in an appropriate amount (to stabilize the system at 6.2-6.8), and viscosity control agent in an appropriate amount (viscosity 50-80 cP at 25°C). In the co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, the proportion of viable Trichoderma harzianum is not less than 80%, and the co-culture is treated by microcapsule embedding to improve environmental stability. The viscosity control agent is a mixture of xanthan gum and carboxymethyl cellulose in a weight ratio of 1:1 to 1:2, which is used to synergistically regulate fluidity and nutrient release performance.

[0020] A preparation method of liquid fertilizer for orange planting, comprising the following specific steps: S1: preparation of basic nutrient solution: dissolve potassium pyrophosphate and ammonium dihydrogen phosphate in deionized water at 60-70°C in turn, add calcium nitrate solution preheated to 50°C, including the following substeps: S101, ultrasonic assisted dissolution (40 kHz, 15 min); S102, stepwise addition of phosphate and calcium salt, interval time ≥ 30 min; S103, real-time monitoring of conductivity change (controlled at 8-10 mS / cm).

[0021] S2: intelligent chelation reaction: pre-chelation of EDTA-Zn and calcium L-aspartate at pH 5.5, addition of polyaspartic acid and nano-silicon dioxide dispersion, including the following substeps: S201, the chelation reaction kettle maintains a nitrogen protection environment, and the nitrogen flow is controlled at 0.8-1.2 L / min, and the oxygen content is <0.5%; S202, online pH automatic control system is used; S203, plasma treatment before adding nano-silicon dioxide.

[0022] S3: biological activity integration: centrifugal concentration of 48-hour co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, activation with chitosan oligosaccharide-brassinolide solution at 28°C for 2 hours, including the following substeps: S301, 0.1% trehalose is added as a protective agent during co-culture of the strains; S302, the centrifugation process is controlled at 4°C, and the relative centrifugal force is 8000xg, and the relationship between the centrifugation time and the bacterial concentration satisfies the formula: t=K×(log10N0-log10Nt) Where K=15 min, N0 is the initial concentration, and Nt is the target concentration; S303, the light intensity in the activation stage is controlled at 2000-3000 lux.

[0023] S4: final adjustment of the system: adopt three-stage gradient mixing process (200 rpm→500 rpm→300 rpm), after membrane filtration (0.45 μm), fill nitrogen and package, including the following sub-steps: S401, the temperature gradient of three-stage mixing is: 25°C→35°C→28°C; S402, pre-coat 0.1% diatomite filter aid layer before membrane filtration; S403, the inner wall of the packaging container is plated with a nano-silver antibacterial layer.

[0024] The above implementation cases are compared by experiment according to the existing technology as follows: Example 1 Nutrient stability verification experiment Experimental process: 1) sample grouping: Control group: commercially available ordinary liquid fertilizer (containing xanthan gum stabilizer); Experimental group: liquid fertilizer of the present application (containing nano-silicon dioxide-poly-aspartic acid composite stabilizing system).

[0025] 2) test conditions: 40°C constant temperature storage for 90 days to simulate long-term storage.

[0026] 3) weekly sampling and testing: centrifugal precipitation (3000 rpm x 10 min); laser particle size analyzer for particle size distribution; ICP for detection of iron, zinc and other trace element retention rate.

[0027] 4) extreme test: temperature cycle test (-5°C to 40°C, daily cycle); simulated transportation vibration (5 Hz x 72 h).

[0028] Table 1: comparison table of nutrient stability test data of example 1 liquid fertilizer Experimental summary: the experimental data clearly show that the composite stabilizing system of the present application has significant advantages. Through 90-day accelerated aging test, the precipitation rate is only 2.3%, which is much lower than that of the control group of 28%, proving that the three-dimensional network structure formed by nano-silicon dioxide and poly-aspartic acid can effectively prevent nutrient separation. It is particularly worth noting that the iron element retention rate is as high as 92% (the control group is only 45%), which shows that the system has outstanding protection effect on trace elements. The coefficient of variation of particle size distribution is as low as 8%, which further verifies its physical stability. These results fully show that the present application has successfully solved the technical problems of easy precipitation and trace element failure of traditional liquid fertilizer.

[0029] Example 2 pH stability verification experiment Experimental process: 1) Sample processing: Control group: commercially available buffer type liquid fertilizer (phosphate buffer system); Experimental group: the present application (citric acid-humic acid-polyaspartic acid complex buffer system).

[0030] 2) Test method: 25℃ / 40℃ double temperature zone long-term monitoring of pH value; Add 0.1M HCl / NaOH to simulate acid-base impact; Metal corrosion test (304 stainless steel sheet immersion for 30 days).

[0031] 3) Dynamic monitoring: Online pH recorder continuously records 90-day data; Corrosion current density is measured by electrochemical workstation.

[0032] Table 2 Comparison of pH stability test data of liquid fertilizer in Example 2 Experimental summary: The experimental results show that the complex buffer system of the present application has outstanding performance in pH stability. In the 90-day monitoring period, the pH fluctuation range is strictly controlled between 5.9-6.2, which is significantly improved compared with the control group of 5.6-7.8 fluctuation. Especially worth noting is that in the acid-base impact test, the recovery time only takes 12 minutes (the control group takes 45 minutes), which shows a rapid self-regulating ability. The corrosion weight loss rate is as low as 0.12 mg / cm², which proves that the system can effectively protect the fertilizing equipment. These data fully verify the effectiveness of the solution to the pH instability problem of liquid fertilizer of the present application.

[0033] Example three Safety verification experiment Experimental process: 1) Field simulation: Set up sandy soil / heavy clay double test fields; Artificially simulate over 20% spraying and drip irrigation operation.

[0034] 2) Monitoring items: Leaf burn rate (image analysis software statistics); Soil EC value stratified detection (0-20cm / 20-40cm); Root scanner observes new root growth.

[0035] 3) Comparison design: Control group: traditional high-concentration fertilizer vs. intelligent controlled-release fertilizer of the present application.

[0036] Table 3 Example 3 liquid fertilizer application safety test data comparison comparison table Experimental summary: The experimental data clearly shows the breakthrough of the application in the aspect of application safety. Under the harsh condition of over 20% application, the leaf burn rate is only 2%, which is much lower than the 35% of traditional products, proving that the intelligent controlled release system can effectively prevent fertilizer damage. In sandy soil, the nutrient leaching amount is controlled at 20% (traditional products reach 65%), which shows that the carrier system significantly improves the nutrient retention capacity. At the same time, the clay soil test shows that the salinization risk is significantly reduced. These results fully verify the effectiveness of the application's solution to the industry's pain point of high risk of liquid fertilizer application, providing a safer and more reliable choice for growers.

[0037] In summary, the liquid fertilizer system of the application solves the key problems of liquid fertilizer in citrus planting: 1) A three-dimensional protection network is constructed by using nanomaterials and high molecular polymers, which reduces the precipitation rate to 2.3% and the trace element retention rate to 92%, and the dual molecular protection mechanism effectively prevents oxidation and precipitation, and still maintains the stability of the composition under extreme conditions, completely solving the layering failure problem of traditional liquid fertilizer; 2) The multi-stage buffer system accurately stabilizes the pH in the range of 5.9-6.2 through synergistic action, and the acid-base impact recovery time is only 12 minutes. The dynamic adjustment mechanism not only protects the equipment (corrosion rate reduced by 82%), but also avoids the decline in fertilizer efficiency caused by pH mutation, significantly reducing the risk of crop damage; 3) The self-adaptive viscosity system realizes the intelligent conversion of "smooth conveying-uniform adhesion", and the intelligent carrier technology reduces the leaching amount in sandy soil by 45% and significantly reduces the salinization risk in clay soil. The safe controlled release mechanism controls the leaf burn rate of over-application to below 2%, significantly reduces the operation threshold, and is especially suitable for small and medium-sized farmers. The three technologies form a complete solution of "stability-safety-convenience", providing a new generation of efficient fertilization choice for citrus planting.

[0038] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present application can be combined or / and combined, even if such combinations or combinations are not explicitly described in the present application. In particular, the features described in various embodiments and / or claims of the present application can be combined and / or combined in various combinations without departing from the spirit and teachings of the present application. All these combinations and / or combinations fall within the scope of the present application.

Claims

1. A liquid fertilizer for orange planting, characterized in that: The invention is prepared from the following components by weight: 10-15 parts of a nitrogen source compounded of calcium nitrate and ammonium sulfate, with a ratio of nitrate nitrogen to ammonium nitrogen of 4:1, 5-8 parts of a phosphorus source compounded of potassium pyrophosphate and diammonium phosphate, 8-12 parts of a potassium source mixed with potassium citrate and potassium sulfate, 0.1-0.3 parts of EDTA-Zn and 1-2 parts of amino acid chelated calcium, 0.3-0.8 parts of polyaspartic acid and 0.05-0.1 parts of nano-silicon dioxide, 1-2 parts of a co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, 0.05-0.2 parts of chitosan oligosaccharide and 10-20 ppm of brassinolide, an appropriate amount of a pH regulator to stabilize the system at 6.2-6.8, and an appropriate amount of a viscosity controller to achieve a viscosity of 50-80 cP at 25°C.

2. The liquid fertilizer for orange cultivation according to claim 1, characterized in that: In the co-culture of Trichoderma harzianum and nitrogen-fixing bacteria, the number of live Trichoderma harzianum bacteria accounts for no less than 80%, and the co-culture is microencapsulated to improve environmental stability. The viscosity controller is a mixture of xanthan gum and carboxymethyl cellulose in a weight ratio of 1:1 to 1:2, which is used to synergistically regulate fluidity and nutrient release performance.

3. A method for preparing liquid fertilizer for orange cultivation according to claim 1, characterized in that: The specific steps include: S1: Prepare the basic nutrient solution: dissolve potassium pyrophosphate and ammonium dihydrogen phosphate in deionized water at 60-70°C, and add calcium nitrate solution preheated to 50°C. S2: Smart chelation reaction: EDTA-Zn and calcium L-aspartate were pre-chelated at pH 5.5, and polyaspartic acid and nano-silica dispersion were added; S3: Bioactivity integration: The 48-hour co-culture of Trichoderma harzianum and nitrogen-fixing bacteria was concentrated by centrifugation and activated with chitosan oligosaccharide-brassinolide solution at 28°C for 2 hours; S4: Final blending of the system: using a three-stage gradient mixing process, followed by membrane filtration and nitrogen filling for packaging.

4. The method for preparing a liquid fertilizer for orange cultivation according to claim 3, wherein: In S1, the following sub-steps are included: S101, using ultrasound to assist dissolution; S102, phosphate and calcium salt are added step by step, with an interval of ≥30min; S103. Monitor conductivity changes in real time.

5. The method for preparing a liquid fertilizer for orange cultivation according to claim 3, characterized in that: In S2, the following sub-steps are included: S201, maintain nitrogen protection environment in the chelating reactor; S202, using an online pH automatic control system; S203, plasma treatment before adding nano-silicon dioxide.

6. The method for preparing a liquid fertilizer for orange cultivation according to claim 5, characterized in that: In step S201, the nitrogen flow rate is controlled at 0.8-1.2 L / min, and the oxygen content is less than 0.5%.

7. The method for preparing a liquid fertilizer for orange cultivation according to claim 3, characterized in that: In S3, the following sub-steps are included: S301, 0.1% trehalose was added as a protective agent during co-culture of bacteria; S302, the centrifugation process is controlled at 4°C and the relative centrifugal force is 8000×g; S303, during the activation phase, the light intensity is controlled at 2000-3000 lux.

8. The method for preparing a liquid fertilizer for orange cultivation according to claim 7, characterized in that: In step S302, the relationship between centrifugation time and bacterial concentration satisfies the formula: t=K×(log10N0-log10Nt) Where K=15min, N0 is the initial concentration, and Nt is the target concentration.

9. The method for preparing a liquid fertilizer for orange cultivation according to claim 3, characterized in that: In S4, the following sub-steps are included: S401, the temperature gradient of the three-stage mixing is: 25℃→35℃→28℃; S402, pre-coat 0.1% diatomaceous earth filter aid layer before membrane filtration; S403. The inner wall of the packaging container is plated with a nano-silver antibacterial layer.

10. The method for preparing a liquid fertilizer for orange cultivation according to claim 9, characterized in that: In the step S403, the thickness of the nano silver coating is 50-80 nm, and the surface roughness Ra is less than or equal to 0.2 μm.

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