Yield-increasing foliar calcium fertilizer and preparation method thereof

Abstract

The invention discloses a yield-increasing foliar calcium fertilizer and a preparation method thereof, and belongs to the technical field of agriculture, and the calcium fertilizer is prepared from an organic complexing calcium source, a small molecule organic acid compound, alginic acid oligosaccharide, a phosphatidylserine analogue, boric acid, a surfactant and water according to a specific ratio. The preparation method comprises the steps of sequential dissolution, complex reaction, low-temperature active ingredient addition and the like. The preparation method comprises the following steps: dissolving the boric acid and the small molecular organic acid in hot water, adding the organic complexing calcium source, adjusting the pH value, carrying out a complexing reaction, cooling, adding the alginate oligosaccharide and the phosphatidylserine analogue, finally adding the surfactant, and uniformly stirring. Through the synergistic effect of all the components, leaf surface absorption and phloem transportation of calcium are effectively promoted, the calcium content of crops is remarkably increased, the occurrence rate of physiological diseases is reduced, and the yield and the fruit quality are improved.

Description

Technical Field

[0001] This invention belongs to the field of agricultural technology, and in particular relates to a foliar calcium fertilizer for increasing yield and its preparation method. Background Technology

[0002] Calcium, as an essential medium element for plant growth and development, plays an irreplaceable and crucial role in cell wall construction, maintenance of biomembrane stability, regulation of enzyme activity, and signal transduction, directly affecting crop growth status, stress resistance, yield, and quality.

[0003] Traditional calcium supplementation methods mainly include soil application and foliar spraying. Soil application of calcium is prone to fixation reactions due to soil environmental factors, leading to a significant reduction in calcium availability and making it difficult for crops to efficiently absorb and utilize it. While current mainstream foliar calcium fertilizers, such as calcium nitrate, calcium chloride, sugar alcohol calcium, and amino acid calcium, compensate for the shortcomings of soil application to some extent, they still generally have the following prominent drawbacks: 1) Low absorption efficiency: calcium ions (Ca... 2+ 1) Positively charged, these particles easily repel the negatively charged particles on the leaf surface, and their large size makes it difficult to penetrate the leaf cuticle barrier, significantly limiting the efficiency of calcium absorption through the leaf surface; 2) Poor internal mobility: While calcium can be transported upwards in the xylem, its mobility in the phloem is extremely poor, making it difficult to effectively transport from functional leaves (old leaves) to new tissues and fruits that urgently require calcium, easily leading to calcium deficiency in the target area and making it difficult to achieve precise calcium supplementation; 3) Large dosage and unstable effects: To ensure the effectiveness of calcium supplementation... In production, multiple high-concentration sprayings are often required, which not only easily causes leaf burn and other pesticide damage, but also significantly increases planting costs and labor intensity. At the same time, its calcium supplementation effect is significantly affected by external factors such as environmental humidity and temperature, and the effect varies greatly under different working conditions, with poor stability. 4) The function is relatively simple: Most foliar calcium fertilizer products on the market only supplement calcium as their core function, lacking synergistic effects with other nutrients and functional factors. Their auxiliary effects in improving the comprehensive stress resistance of crops (such as cold resistance, drought resistance, and disease resistance) and promoting yield and quality improvement are limited.

[0004] In summary, developing a new type of foliar calcium fertilizer that is rapidly absorbed, highly mobile within the plant, requires minimal dosage, has multiple functions, and is environmentally friendly is of great practical significance for promoting green and efficient agricultural development and improving crop yield and quality. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a foliar calcium fertilizer for increasing yield and its preparation method. This invention constructs a composite system that, through the synergistic effect of its components, achieves precise and efficient replenishment of calcium nutrition to plants.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A foliar calcium fertilizer for increasing yield comprises the following raw materials in weight percentages: 10-20% organic complex calcium source, 5-10% small molecule organic acid complex, 0.5-2% alginate oligosaccharide, 0.1-0.5% phosphatidylserine analogue, 0.5-1.5% boric acid, 0.05-0.2% surfactant, and the balance being water.

[0007] Furthermore, the organic complexed calcium source is a mixture of calcium lignosulfonate and calcium propylene glycol, with a mass ratio of (1-3):1.

[0008] Calcium lignosulfonate has a large molecular weight and good stability; calcium propylene glycol has a small molecular weight and high activity. The combination of the two provides both rapid and sustained effects.

[0009] Furthermore, the small molecule organic acid complex is a mixture of citric acid, malic acid and L-proline in a mass ratio of 2:2:1.

[0010] This complex not only stabilizes calcium ions, but also (especially L-proline) can act as an osmotic regulator, reducing cell water potential, promoting calcium absorption with water, and inducing plant stress resistance.

[0011] Furthermore, the molecular weight of the alginate oligosaccharide is 800-2000 Da.

[0012] As a plant immune inducer, alginate oligosaccharides can activate the crop's own stress-resistant immune system, open absorption channels, promote photosynthesis, and work with calcium to enhance cell wall strength.

[0013] Furthermore, the specific preparation method of the phosphatidylserine analogue includes the following steps: S1. Soybean lecithin was dispersed in an acetate-sodium acetate buffer solution to form an emulsion. L-serine was added and stirred. Phospholipase D was added and stirred again. After the reaction was completed, the mixture was inactivated, allowed to stand and separate into layers, and concentrated under reduced pressure to obtain a primary modified phospholipid concentrate. S2. Add β-sitosterol and betaine hydrochloride to the primary modified phospholipid concentrate, and shear and disperse to obtain a biomimetic membrane precursor structure, which is the phosphatidylserine analogue.

[0014] Phosphatidylserine analogues are products derived from soybean lecithin through enzymatic hydrolysis. Their structure is similar to the phospholipid bilayer of cell membranes, effectively promoting the fusion of calcium fertilizer components with leaf cell membranes, mimicking biomembrane signals, and specifically facilitating long-distance transport of calcium ions through the phloem.

[0015] Traditional processes aim to completely convert PC into high-purity PS, resulting in extremely high costs. This invention takes the opposite approach, deliberately controlling the conversion degree to obtain a phospholipid mixture. Unreacted PC serves as the foundation of the membrane structure, while newly generated PS provides negatively charged sites for interaction with calcium ions and biological signals. PA, as a zwitterion, helps form a non-layered phase, collectively enhancing the affinity and fusion capacity with plant cell membranes (also a mixture of multiple phospholipids). β-Sitosterol is an important component of plant cell membranes. Adding it to the phospholipid system significantly improves the stability and fluidity of the mixed membrane, more realistically mimicking the plant cell membrane environment, reducing the "foreignness" of exogenous substances, and thus promoting transmembrane processes. Betaine hydrochloride, on the one hand, acts as an excellent osmotic regulator, temporarily adjusting the water potential of stomata or epidermal cells during foliar spraying, creating a microenvironment to promote absorption; on the other hand, its zwitterionic properties interact with the polar head groups of phospholipids, stabilizing the entire composite system. This method uses inexpensive raw materials and controlled processes to prepare a high-performance functional additive. Its cost is far lower than that of high-purity PS, but through the biomimetic synergistic effect between components, it achieves a better or equivalent effect in promoting the specific function of calcium ion transport.

[0016] Furthermore, the boric acid is used to stabilize the cell wall pectin structure and to form a synergistic absorption effect with calcium (Ca-B synergy).

[0017] Furthermore, the surfactant is an alkyl polysaccharide.

[0018] Alkyl polysaccharides are environmentally friendly and can significantly reduce the surface tension of spray solutions.

[0019] This invention also provides a method for preparing a foliar calcium fertilizer to increase yield, comprising the following steps: (1) Dissolve boric acid and a small molecule organic acid complex in heated water to obtain an acidic mixture; (2) Maintain the temperature, add an organic complex calcium source to the acidic mixture, adjust the pH to 5-6, stir the reaction to obtain a calcium complex solution; (3) Cool the calcium complex solution, then add alginate oligosaccharide and phosphatidylserine analogue in sequence, stir, and obtain a solution; (4) Add surfactant to the solution, continue stirring, cool to room temperature, and filter to obtain the foliar calcium fertilizer for increasing yield.

[0020] Furthermore, the temperature of the heated water is 50-60°C; the cooling is reduced to 35-40°C.

[0021] Furthermore, the stirring reaction time is 60-90 minutes; the stirring time is 30 minutes; and the continued stirring time is 15 minutes.

[0022] The present invention also provides the application of a foliar calcium fertilizer for increasing yield in the preparation of a formulation for preventing or treating physiological diseases caused by calcium deficiency in plants.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects: 1) Highly efficient absorption and transport: Through the synergistic effect of organic complex calcium source compound (calcium lignosulfonate and calcium propylene glycol) and biomimetic phosphatidylserine analogue, the leaf surface absorption efficiency of calcium is significantly improved, and long-distance transport of calcium in the phloem is promoted, so as to achieve precise calcium supplementation.

[0024] 2) Enhance stress resistance and disease prevention: Alginic acid oligosaccharides act as immune inducers to activate the plant's stress resistance system and work synergistically with calcium to enhance cell wall strength; boric acid stabilizes the cell wall structure, and together they effectively reduce the incidence of calcium deficiency physiological diseases such as blossom-end rot.

[0025] 3) Synergistic effect and multiple functions: The small molecule organic acid complex (containing L-proline) has the functions of calcium stabilization, osmotic regulation and anti-stress induction.

[0026] 4) Environmentally friendly and safe to use: Alkyl polysaccharide glycosides are used as green surfactants to reduce liquid surface tension; the process is mild and the pH is moderate, which does not easily cause leaf burn, reduces the number of times and the amount used, and saves costs.

[0027] 5) Feasible process and controllable cost: Phosphatidylserine analogs are prepared by controlled enzymatic hydrolysis, the raw materials are readily available, and the cost is significantly lower than that of high-purity products, which is conducive to industrialization and promotion.

[0028] In summary, this invention provides a foliar calcium fertilizer that is rapidly absorbed, highly mobile, multifunctional, and highly safe. It can effectively solve the problems of low absorption efficiency, poor mobility, and limited functionality of traditional calcium fertilizers, and has significant effects on increasing yield, improving quality, and enhancing disease resistance. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0032] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0033] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0034] This invention provides a method for preparing a foliar calcium fertilizer to increase yield, comprising the following steps: (1) Premixing in the reactor: Add metered water to the reactor and heat to 50-60℃ (e.g., 55℃). Add boric acid and small molecule organic acid complex (citric acid, malic acid, L-proline) in sequence while stirring. Stir until completely dissolved to form an acidic mixture (mixture A). (2) Complexation reaction: While maintaining the temperature, slowly add the organic complex calcium source (calcium lignosulfonate and calcium propylene glycol) to the mixture A, control the pH value between 5.0 and 6.0 (e.g., pH=5.5), and continue stirring for 60-90 minutes (e.g., 75 minutes) to form a stable calcium complex solution (solution B). (3) Addition of bioactive ingredients: Cool solution B to 35-40℃ (e.g., 38℃), add alginate oligosaccharide and phosphatidylserine analogue in sequence, stir at low speed for 30 minutes to ensure full dispersion and homogeneity, and obtain solution (solution C). (4) Post-treatment: Add surfactant alkyl polysaccharide to solution C, stir for 15 minutes, cool to room temperature, filter, and the foliar calcium fertilizer for increasing yield is obtained.

[0035] A foliar calcium fertilizer for increasing yield can be prepared using the above preparation method, comprising the following raw materials by mass percentage: 10-20% (e.g., 15% or 18%) of organic complex calcium source, 5-10% (e.g., 7.5% or 9%) of small molecule organic acid complex, 0.5-2% (e.g., 1% or 1.5%) of alginate oligosaccharide, 0.1-0.5% (e.g., 0.3% or 0.4%) of phosphatidylserine analogue, 0.5-1.5% (e.g., 1% or 1.2%) of boric acid, 0.05-0.2% (e.g., 0.1% or 0.15%) of surfactant, and the balance being water.

[0036] In some optional embodiments of the present invention, the organic complexed calcium source is a mixture of calcium lignosulfonate and calcium propylene glycol in a mass ratio of (1-3):1. Exemplarily, in the following preferred embodiments of the present invention, the mass ratio of calcium lignosulfonate to calcium propylene glycol is 2:1 or 2.5:1.

[0037] In some optional embodiments of the present invention, the small molecule organic acid complex is a mixture of citric acid, malic acid and L-proline in a mass ratio of 2:2:1.

[0038] In some optional embodiments of the present invention, the molecular weight of alginate oligosaccharides is 800-2000 Da. Exemplarily, in the following preferred embodiments of the present invention, the molecular weight of alginate oligosaccharides is 1000 Da or 1500 Da.

[0039] In some optional embodiments of the present invention, the specific preparation method of the phosphatidylserine analogue includes the following steps: S1. In the reactor, add 100 parts of soybean lecithin (phosphatidylcholine PC content ≥60%) and 300-400 parts (e.g., 350 parts) of acetate-sodium acetate buffer (0.1M, pH=5.5-6.0, e.g., pH=5.8), stir slowly and heat to 45-50℃ (e.g., 45℃) to fully disperse the lecithin and form a uniform emulsion; add 20 parts of L-serine and continue stirring until most of it dissolves; then add 2 parts of phospholipase D (PLD, derived from Streptomyces, enzyme activity ≥2000U / g), and maintain the reaction temperature at 48±2℃. Stir slowly (to avoid excessive foaming), and control the reaction time to 8-12 hours (e.g., 10 hours). After the reaction is complete, heat the reaction system to 85°C and maintain it for 30 minutes to completely inactivate phospholipase D. Transfer the reaction mixture to a separatory apparatus, add an equal volume of hot ethanol (60°C), stir thoroughly, and allow it to stand for separation. Collect the upper alcohol phase (rich in modified phospholipids), and the lower aqueous phase (containing residual serine, buffer salts, etc.) can be recycled. Concentrate the upper alcohol phase under reduced pressure at 55-60°C (e.g., 55°C) to recover the ethanol and obtain a viscous primary modified phospholipid concentrate. By controlling the reaction time, enzyme amount, and stirring intensity, a portion of phosphatidylcholine (PC) is converted into phosphatidylserine (PS), while simultaneously generating intermediate products such as phosphatidic acid (PA), forming a PC / PS / PA complex phospholipid system. This mixture exhibits different physicochemical properties and biological activities compared to pure PS. S2. Transfer the above primary concentrate to a high-speed shear dispersion vessel, maintain the temperature at 60-65℃ (e.g., 60℃), add 3 parts β-sitosterol (phytosterol) and 5 parts betaine hydrochloride, and shear disperse at a speed of 5000-8000 rpm (e.g., 6000 rpm) for 30-45 minutes (e.g., 45 minutes) until a uniform, semi-transparent viscous paste is formed. This process allows phytosterol and betaine molecules to embed into the layered structure of the complex phospholipid, forming a biomimetic membrane precursor structure, namely a phosphatidylserine analogue.

[0040] As an optional embodiment of the present invention, an enhanced foliar calcium fertilizer for increasing yield is also provided, comprising the following raw materials by weight percentage: 10-20% (e.g., 15% or 18%) of organic complex calcium source, 5-10% (e.g., 7.5% or 9%) of small molecule organic acid complex, 0.5-2% (e.g., 1% or 1.5%) of alginate oligosaccharide, 0.1-0.5% (e.g., 0.3% or 0.4%) of phosphatidylserine analogue, 0.5-1.5% (e.g., 1% or 1.2%) of boric acid, 0.05-0.2% (e.g., 0.1% or 0.15%) of surfactant, 0.5-2% (e.g., 0.5% or 1%) of sugar alcohol chelated magnesium, 1-3% (e.g., 2% or 3%) of potassium silicate, 0.1-0.3% (e.g., 0.1% or 0.2%) of amino acid chelated zinc, and the balance being water.

[0041] The role of sugar alcohol chelated magnesium: Calcium and magnesium have a complex relationship in plants, exhibiting both synergistic and antagonistic effects. Adequate magnesium presence maintains cell membrane stability, regulates calcium ion channel activity, promotes balanced calcium ion absorption, and prevents magnesium deficiency caused by high calcium levels. Sugar alcohol chelated magnesium shares similar transport characteristics with sugar alcohol calcium, co-transporting through the xylem and phloem. Magnesium promotes photosynthesis, providing more ATP for active calcium ion transport (such as calcium pumps) and cell wall construction (which requires energy), thereby indirectly enhancing calcium transport and deposition efficiency. Magnesium, along with boron, participates in carbohydrate transport, working synergistically with calcium to comprehensively improve fruit quality.

[0042] The role of potassium silicate: Calcium is mainly deposited in the pectin layer of cell walls to form calcium pectate, while silicon is deposited in the form of silica gel between the cellulose microfibrils of cell walls and on the outer walls of epidermal cells. Both strengthen the cell walls at different levels, forming a dual physical and chemical barrier, significantly improving disease resistance (especially to fungal diseases) and stress tolerance, with effects far exceeding those of calcium alone. Silicon enhances the mechanical support of plant tissues and improves vascular structure, potentially facilitating the upward transport and more even distribution of calcium ions in the xylem. Silicon enhances the stability of epidermal cell walls, while phosphatidylserine analogues optimize membrane permeability and transport. Together, they synergistically improve the leaves' ability to retain and transport fertilizer internally at both the outer wall and membrane system levels.

[0043] The role of amino acid-chelated zinc: Zinc promotes auxin synthesis, stimulating cell division and elongation in newly formed tissues (such as apical meristems and young fruits), which are precisely the areas with the highest calcium demand. This acts as a signal guide, making the plant's need for calcium absorption and transport to these areas more urgent, thereby improving the targeted utilization of calcium fertilizer. As a component of carbonic anhydrase, zinc participates in CO2 fixation and synergistically enhances photosynthesis with magnesium, providing energy for calcium transport. Both zinc and L-proline participate in stress resistance responses, jointly enhancing the efficiency of calcium absorption and utilization by plants under adverse conditions (such as low temperature and drought).

[0044] The preparation method of this enhanced yield-increasing foliar calcium fertilizer includes the following steps: (1) Premixing in the reactor: Add metered water to the reactor and heat to 50-60℃ (e.g., 55℃). Add boric acid and small molecule organic acid complex (citric acid, malic acid, L-proline) in sequence while stirring. Stir until completely dissolved to form an acidic mixture. (2) Complexation reaction: While maintaining the temperature, slowly add the organic complex calcium source (calcium lignosulfonate and calcium propylene glycol) to the mixture A, control the pH value between 5.0 and 6.0 (e.g., pH=5.5), and continue stirring for 60-90 minutes (e.g., 75 minutes) to form a stable calcium complex solution; (3) Addition of bioactive ingredients: Cool solution B to 35-40℃ (e.g., 38℃ or 40℃), add sugar alcohol chelated magnesium and potassium silicate in sequence, stir to dissolve, then add alginate oligosaccharide, phosphatidylserine analog and amino acid chelated zinc, stir at low speed for 30 minutes to ensure full dispersion and homogeneity, and obtain the solution; (4) Post-treatment: Add surfactant alkyl polysaccharide to solution C, stir for 15 minutes, cool to room temperature, filter, and the enhanced foliar calcium fertilizer for increasing yield is obtained.

[0045] In some optional embodiments of the present invention, the surfactant is an alkyl polysaccharide.

[0046] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0047] Unless otherwise specified, the term "parts" in this invention refers to parts by weight.

[0048] All raw materials used in this invention were purchased from the market.

[0049] The technical solution of the present invention will be further illustrated by the following embodiments.

[0050] Example 1 A foliar calcium fertilizer for increasing yield, with a total mass percentage of 100%, has the following specific components: Organic complexed calcium source: 18% (of which calcium lignosulfonate: calcium propylene glycol = 2.5:1, by mass, the same below); Small molecule organic acid complex: 9% (where citric acid: malic acid: L-proline = 2:2:1, mass ratio, the same below); Alginic acid oligosaccharide (molecular weight 1000 Da): 1.5%; Phosphatidylserine analogue: 0.4%; Boric acid: 1.2%; Surfactant (alkyl polysaccharide): 0.15%; Water: Balance (to 100%).

[0051] A method for preparing a foliar calcium fertilizer for increasing yield includes the following steps: (I) Preparation of phosphatidylserine analogues S1. Take 100g of soybean lecithin (PC≥60%) and disperse it in 350g of acetate-sodium acetate buffer (0.1M, pH=5.8), and form an emulsion at 45℃; S2. Add 20g of L-serine, stir to dissolve, add 2g of phospholipase D (2000U / g), and stir slowly at 48℃ for 10 hours. S3. Heat to 85℃ and maintain for 30 minutes to inactivate the enzyme. Add an equal volume of 60℃ hot ethanol, stir, and let stand to separate into layers. S4. Collect the upper alcohol phase, concentrate under reduced pressure at 55°C to remove ethanol, and obtain primary modified phospholipid concentrate. S5. Add 3g of β-sitosterol and 5g of betaine hydrochloride to the concentrate, and disperse it at 6000rpm for 40 minutes at 60℃ to obtain a homogeneous viscous paste, which is a phosphatidylserine analog. (II) Preparation of calcium fertilizer (1) Add measured water to the reaction vessel, heat to 55°C, add boric acid and small molecule organic acid complex, stir to dissolve, and obtain an acidic mixture; (2) Keep at 55°C, slowly add organic complex calcium source, adjust pH to 5.5 with dilute acid or base, stir reaction for 75 minutes to obtain calcium complex solution; (3) Cool the solution to 38°C, add alginate oligosaccharide and phosphatidylserine analogue in sequence, and stir for 30 minutes; (4) Add alkyl polysaccharide, continue stirring for 15 minutes, cool to 25°C, filter, and obtain the finished product foliar calcium fertilizer for increasing yield.

[0052] Example 2 A foliar calcium fertilizer for increasing yield, with a total mass percentage of 100%, has the following specific components: Organic complexed calcium source: 15% (of which calcium lignosulfonate: calcium propylene glycol = 2:1); Small molecule organic acid complex: 7.5% (of which citric acid: malic acid: L-proline = 2:2:1); Alginic acid oligosaccharide (molecular weight 1500 Da): 1%; Phosphatidylserine analogue: 0.3%; Boric acid: 1%; Surfactant (alkyl polysaccharide): 0.1%; Water: Balance (to 100%).

[0053] The preparation method is the same as in Example 1.

[0054] Comparative Example 1 Same as Example 1, except that no alginate oligosaccharides are added, and their mass fraction is made up by water.

[0055] Comparative Example 2 Same as Example 1, except that no phosphatidylserine analogue is added, and its mass fraction is made up by water.

[0056] Comparative Example 3 Commercially available sugar alcohol calcium fertilizer (sugar alcohol complex calcium, Ca≥12%, pH5-7, containing appropriate amount of boron) was used as a control.

[0057] Comparative Example 4 Formula: 15% calcium nitrate (providing an equal amount of calcium ions), 5% citric acid, 1% boric acid, 0.1% alkyl polysaccharide glycoside, water balance. Dissolve and mix all ingredients at room temperature to obtain calcium fertilizer.

[0058] Experimental Example 1: Experimental crop: Greenhouse tomato (variety 'Pink Crown').

[0059] Experimental Design: Seven treatments were set up, including Examples 1-2, Comparative Examples 1-4 (products), and a water control, with each treatment replicated three times. The product was sprayed once each at the initial flowering stage, young fruit stage, and fruit enlargement stage, diluted 500 times. Fruit calcium content, blossom-end rot incidence, single fruit weight, and yield per acre were measured, and the results are shown in Table 1.

[0060] Table 1. Test results of products from Examples 1-2, Comparative Examples 1-4, and water control. Note: Data are expressed as "mean ± standard deviation", and the incidence of navel rot is the average of three surveys.

[0061] As shown in Table 1, the calcium content of the fruits in Examples 1 and 2 reached 185 mg / kg and 178 mg / kg, respectively, significantly higher than all comparative examples and the water control, indicating that the product of this invention can effectively improve the absorption and transport efficiency of calcium. The incidence of blossom-end rot in Examples 1 and 2 was only 2.1% and 2.5%, respectively, far lower than the comparative examples (maximum 8.9%) and the water control (12.3%), indicating that the product of this invention has a significant advantage in preventing physiological diseases caused by calcium deficiency. The yield of Example 1 reached 4850 kg / mu, an increase of about 31.8% compared to the water control and about 18.3% compared to commercially available sugar alcohol calcium (comparative example 3), showing that the product of this invention has a significant effect on promoting fruit enlargement and increasing overall yield. Comparative example 1 showed significantly lower calcium content and disease resistance than the examples, indicating that alginate oligosaccharides play an important role in inducing stress resistance and promoting absorption. The calcium content and yield of comparative example 2 further decreased, confirming the key role of phosphatidylserine analogues in promoting calcium transport in the phloem.

[0062] Experimental Example 2: Experimental crop: Spring soybean (variety 'Qinong 5', indeterminate pod setting habit, 100-seed weight 19.4g).

[0063] Experimental Design: Seven treatments were set up, including Examples 1-2, Comparative Examples 1-4 (products), and a water control, with each treatment replicated three times. The product was sprayed once each at the initial flowering, pod-setting, and grain-filling stages of soybeans, diluted 500 times. Grain calcium content, incidence of calcium deficiency physiological disorders, 100-grain weight, yield per acre, and quality indicators were measured. The results are shown in Table 2.

[0064] Table 2. Test results of products from Examples 1-2, Comparative Examples 1-4, and water control. Note: Data are expressed as "mean ± standard deviation". The incidence of calcium deficiency physiological diseases is the average of three surveys (symptoms include apical bud necrosis, leaf margin scorch, and pod malformation).

[0065] Results analysis: As shown in Table 2, the grain calcium content of Examples 1 and 2 reached 485 mg / kg and 472 mg / kg, respectively, significantly higher than all comparative examples and the water control. The incidence of calcium deficiency physiological disorders in Examples 1 and 2 was only 3.2% and 3.8%, respectively, far lower than the comparative examples (maximum 11.5%) and the water control (15.2%). The yield of Example 1 reached 218 kg / mu, an increase of approximately 32.1% compared to the water control and approximately 17.8% compared to conventional sugar alcohol calcium (comparative example 3).

[0066] In terms of quality, the protein content of Examples 1 and 2 reached 41.25% and 40.98%, respectively, and the fat content reached 22.18% and 21.95%, respectively, both significantly better than the control group. This indicates that the improvement in calcium nutrition not only increased yield but also promoted the synthesis and accumulation of protein and oil, thereby enhancing the nutritional quality and economic value of soybeans.

[0067] Comparative Example 1 showed significantly lower calcium content and disease resistance than the Example, indicating that alginate oligosaccharides play an important role in inducing stress resistance and promoting absorption. Comparative Example 2 showed a further decrease in calcium content and yield, confirming the crucial role of phosphatidylserine analogues in promoting calcium transport in the phloem.

[0068] Example 3 An enhanced foliar calcium fertilizer for increasing yield, with a total mass percentage of 100%, has the following specific components: Organic complexed calcium source: 18% (of which calcium lignosulfonate: calcium propylene glycol = 2.5:1); Small molecule organic acid complex: 9% (of which citric acid: malic acid: L-proline = 2:2:1); Alginic acid oligosaccharide (molecular weight 1000 Da): 1.5%; Phosphatidylserine analogue: 0.4%; Boric acid: 1.2%; Sugar alcohol chelated magnesium (Mg≥6%): 1%; Potassium silicate (K₂O∶SiO₂=1∶2, mass ratio, the same below): 2%; Amino acid chelated zinc (Zn≥10%): 0.2%; Surfactant (alkyl polysaccharide): 0.15%; Water: Balance (to 100%).

[0069] A method for preparing an enhanced foliar calcium fertilizer for increasing yield includes the following steps: (a) Preparation of phosphatidylserine analogues: Same as in Example 1; (II) Preparation of calcium fertilizer (1) Add measured water to the reaction vessel, heat to 55°C, add boric acid and small molecule organic acid complex, stir to dissolve, and obtain an acidic mixture; (2) Keep at 55°C, slowly add organic complex calcium source, adjust pH to 5.5 with dilute acid or base, stir reaction for 75 minutes to obtain calcium complex solution; (3) Cool the solution to 40°C, add sugar alcohol chelated magnesium and potassium silicate first, stir to dissolve, then add alginate oligosaccharide, phosphatidylserine analog and amino acid chelated zinc, and stir for 30 minutes; (4) Add alkyl polysaccharide, continue stirring for 15 minutes, cool to 25°C, filter, and obtain the enhanced product foliar calcium fertilizer for increasing yield.

[0070] Example 4 An enhanced foliar calcium fertilizer for increasing yield, with a total mass percentage of 100%, has the following specific components: Organic complexed calcium source: 15% (of which calcium lignosulfonate: calcium propylene glycol = 2:1); Small molecule organic acid complex: 7.5% (of which citric acid: malic acid: L-proline = 2:2:1); Alginic acid oligosaccharide (molecular weight 1500 Da): 1%; Phosphatidylserine analogue: 0.3%; Boric acid: 1%; Sugar alcohol chelated magnesium (Mg≥6%): 0.5%; Potassium silicate (K2O∶SiO2=1∶2, mass ratio, the same below): 3%; Amino acid chelated zinc (Zn≥10%): 0.1%; Surfactant (alkyl polysaccharide): 0.1%; Water: Balance (to 100%).

[0071] The preparation method is the same as in Example 3.

[0072] Comparative Example 5 Same as Example 3, except that the sugar alcohol chelated magnesium is replaced with magnesium sulfate with the same magnesium content.

[0073] Comparative Example 6 Same as Example 3, except that potassium silicate in Example 3 is replaced with sodium silicate with the same silicon content.

[0074] Comparative Example 7 Same as Example 3, except that the amount of sugar alcohol chelated magnesium is 0.2%.

[0075] Experimental Example 3 Experimental crop: Greenhouse tomato (variety 'Pink Crown') Experimental Design: Six treatments were set up, including Examples 3-4, Comparative Examples 5-7 (product), and a water control, with each treatment replicated three times. The product was sprayed once each at the initial flowering stage, young fruit stage, and fruit enlargement stage, diluted 500 times. Fruit calcium content, blossom-end rot incidence, single fruit weight, yield per acre, and fruit sugar content were measured. The results are shown in Table 3.

[0076] Table 3. Test results of products from Examples 3-4, Comparative Examples 5-7, and water control. Note: Data is expressed as "mean ± standard deviation"; sugar content is the soluble solids content, reflecting fruit quality.

[0077] As shown in Table 3, Examples 3 and 4 performed best in all indicators, demonstrating the perfect synergy between sugar alcohol chelated magnesium, potassium silicate, and amino acid chelated zinc with the core system. This not only further improved calcium nutrition efficiency but also significantly improved fruit quality (increased sugar content). Comparative Example 5 showed lower performance in all indicators than Example 3, indicating the unique advantage of sugar alcohol chelated magnesium in promoting calcium-magnesium co-transport. Comparative Example 6 was slightly inferior in disease resistance (slightly higher in blossom-end rot) and quality (lower sugar content), highlighting the additional value of potassium ions in improving fruit quality and regulating ion balance. Comparative Example 7 (low magnesium) was not effective, proving that sufficient magnesium is essential for synergy.

[0078] Comparing Tables 1 and 3, it can be seen that Example 3, by adding sugar alcohol chelated magnesium, potassium silicate, and amino acid chelated zinc, is significantly superior to Example 1 in terms of calcium absorption efficiency, disease control, yield increase, and fruit quality. In particular, the sugar content is significantly increased, indicating that the enhanced formula has a synergistic advantage in promoting photosynthetic product accumulation and quality formation. Example 4 also shows comprehensive superiority over Example 2, further verifying that the synergistic addition of magnesium, silicon, and zinc can stably improve the overall effectiveness of calcium fertilizer under different ratios, especially in disease control and quality improvement.

[0079] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A foliar calcium fertilizer for increasing yield, characterized in that, The raw materials include the following percentages by weight: 10-20% organic complex calcium source, 5-10% small molecule organic acid complex, 0.5-2% alginate oligosaccharide, 0.1-0.5% phosphatidylserine analogue, 0.5-1.5% boric acid, 0.05-0.2% surfactant, and the balance being water.

2. The foliar calcium fertilizer for increasing yield according to claim 1, characterized in that, The organic complexed calcium source is a mixture of calcium lignosulfonate and calcium propylene glycol, with a mass ratio of (1-3):

1.

3. The foliar calcium fertilizer for increasing yield according to claim 1, characterized in that, The small molecule organic acid complex is a mixture of citric acid, malic acid and L-proline in a mass ratio of 2:2:

1.

4. The foliar calcium fertilizer for increasing yield according to claim 1, characterized in that, The molecular weight of the alginate oligosaccharide is 800-2000 Da.

5. The foliar calcium fertilizer for increasing yield according to claim 1, characterized in that, The specific preparation method of the phosphatidylserine analogue includes the following steps: Soybean lecithin was dispersed in an acetate-sodium acetate buffer solution to form an emulsion. L-serine was added and stirred. Phospholipase D was then added and stirred continuously. After the reaction was completed, the lecithin was inactivated, allowed to stand and separate into layers, and concentrated under reduced pressure to obtain a primary modified phospholipid concentrate. β-sitosterol and betaine hydrochloride were added to the primary modified phospholipid concentrate, and the mixture was sheared and dispersed to obtain a biomimetic membrane precursor structure, which is the phosphatidylserine analogue.

6. The foliar calcium fertilizer for increasing yield according to claim 1, characterized in that, The surfactant is an alkyl polysaccharide.

7. A method for preparing a foliar calcium fertilizer for increasing yield as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Dissolve boric acid and a small molecule organic acid complex in heated water to obtain an acidic mixture; (2) Maintain the temperature, add an organic complex calcium source to the acidic mixture, adjust the pH to 5-6, stir the reaction to obtain a calcium complex solution; (3) Cool the calcium complex solution, then add alginate oligosaccharide and phosphatidylserine analogue in sequence, stir, and obtain a solution; (4) Add surfactant to the solution, continue stirring, cool to room temperature, and filter to obtain the foliar calcium fertilizer for increasing yield.

8. The preparation method according to claim 7, characterized in that, The temperature of the heated water is 50-60℃; the temperature is reduced to 35-40℃.

9. The preparation method according to claim 7, characterized in that, The stirring reaction time is 60-90 minutes; the stirring time is 30 minutes; and the stirring time is 15 minutes.

10. The use of a foliar calcium fertilizer for increasing yield as described in any one of claims 1-6 in the preparation of a formulation for preventing or treating physiological diseases caused by calcium deficiency in plants.

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