A solid hydrogen-producing particle and a method for applying the same to drought resistance of plants

Abstract

This invention discloses a solid hydrogen-producing particle and its application method in plant drought resistance, belonging to the field of agricultural drought resistance technology. The solid hydrogen-producing particle consists of a hydrogen-producing core and a fast-dissolving controlled-release coating layer. The hydrogen-producing core contains a hydrogen donor, a penetration-promoting dispersant, a binder, and a hydrogen production rate regulator. The coating layer contains polyvinyl alcohol, polyethylene glycol, sodium alginate, and a leaf affinity modifier. In application, the particles are dissolved in irrigation water in a certain proportion and stirred to form a high-concentration hydrogen-rich water spray solution, which is then immediately sprayed onto plant leaves. The particles of this invention are specifically designed for foliar spraying, achieving instant dissolution and use. The spray solution has good leaf spreading and retention properties, high hydrogen absorption rate by leaves, and significantly better drought resistance than traditional hydrogen-rich water spraying and soil burial of solid hydrogen-producing materials. It is simple to operate and easy to promote on a large scale.

Description

Technical Field

[0001] This invention relates to the field of agricultural drought-resistant cultivation technology, specifically to a solid hydrogen-producing particle that can be rapidly dissolved in irrigation water to form a hydrogen-rich spray solution, its preparation method, and a method for improving plant drought resistance by using the solid hydrogen-producing particle through foliar spraying. Background Technology

[0002] Drought stress is one of the most severe abiotic stresses facing global agricultural production, seriously restricting crop growth, development, yield, and quality. Against the backdrop of increasingly severe global climate change, the frequency, intensity, and duration of droughts are all on the rise, posing a significant threat to food security and sustainable agricultural development.

[0003] In recent years, hydrogen, as a novel gaseous signaling molecule, has attracted widespread attention in the field of plant stress resistance. Studies have shown that hydrogen participates in plant responses to various abiotic stresses such as drought, salinity, and high temperature, enhancing plant stress resistance through mechanisms such as regulating antioxidant enzyme activity, adjusting osmotic balance, inducing stress-response gene expression, and reducing stomatal aperture. Currently, hydrogen application in agriculture is mainly divided into two categories: root application and foliar application. Root application includes hydrogen-rich water irrigation and the burial of solid hydrogen-producing materials. Its drawbacks are: hydrogen has a long diffusion path in the soil, is easily consumed by soil microorganisms or escapes from the soil surface, resulting in a low proportion of hydrogen reaching the plant roots; and fluctuations in soil moisture content significantly affect the hydrogen production rate and hydrogen retention time, making it impossible to guarantee a stable hydrogen supply effect. Foliar application typically uses hydrogen-rich water spraying, which involves directly spraying hydrogen-rich water, obtained through electrolysis or high-pressure dissolution, onto plant leaves.

[0004] Compared to root application, foliar spraying offers advantages such as direct action, rapid effect, and high hydrogen utilization – hydrogen can directly enter leaf tissue through stomata and quickly participate in drought resistance signal regulation. However, existing foliar hydrogen-rich water spraying technologies still have the following problems: Hydrogen escape. Hydrogen has low solubility in water and easily escapes from the surface of droplets. Hydrogen-rich water prepared by traditional electrolysis escapes in large quantities within minutes after being sprayed onto leaves, resulting in a much lower effective hydrogen dose absorbed by the leaves than expected. Difficult on-site preparation. Hydrogen-rich water needs to be prepared on-site using electrolysis equipment, which is costly, requires power, and is not portable, making it difficult to use in remote areas and fields lacking power facilities. Droplet spreading and retention issues. Ordinary hydrogen-rich water has high surface tension, easily forming large droplets that roll off after being sprayed onto leaf surfaces, or evaporating too quickly, resulting in low hydrogen absorption efficiency by the leaves. Although this can be improved by adding surfactants, current technology lacks products that integrate hydrogen production and foliar spreading functions. Lack of targeted solid products. Existing solid hydrogen production materials are mainly designed for soil burial applications, and their hydrogen production rate, solubility characteristics, and auxiliary material composition are not suitable for "instant dissolution and spraying" foliar application. Therefore, there is a need to develop a solid hydrogen production product specifically for foliar spraying that can quickly dissolve in irrigation water to form a high-concentration hydrogen-rich solution, and whose spray solution has good foliar spreadability and retention, enabling efficient and continuous absorption and utilization of hydrogen by plant leaves. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a solid hydrogen-producing particle, its preparation method, and its application method. This solves the problems of short retention time and poor moisture retention of the solid hydrogen-producing particle on plant leaves. It can quickly dissolve and release high concentrations of hydrogen, has good leaf spreading and retention properties, improves the absorption efficiency of hydrogen by plant leaves, and enhances drought resistance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A solid hydrogen-producing particle, comprising a hydrogen-producing core and a rapidly soluble controlled-release coating layer covering the outside of the hydrogen-producing core.

[0007] The hydrogen production core contains the following raw materials in parts by weight: 40-70 parts hydrogen donor, 10-25 parts permeation dispersant, 5-15 parts binder, and 3-10 parts hydrogen production rate regulator.

[0008] The hydrogen donor is one or more of nano-silica, magnesium hydride, sodium borohydride, and calcium hydride, with magnesium hydride being preferred. Magnesium hydride has a theoretical hydrogen production capacity of 15.2 wt%, which is 1.8 times that of traditional magnesium powder (approximately 8.3 wt%), allowing for the preparation of higher concentrations of hydrogen-rich water spray solutions at the same dosage. More importantly, the hydrolysis products of magnesium hydride are magnesium hydroxide and hydrogen gas. Magnesium hydroxide is weakly alkaline and non-corrosive to plant leaves, exhibiting superior safety compared to the hydrolysis products of more reactive metals.

[0009] The penetration-enhancing dispersant is one or more of modified starch and microcrystalline cellulose. Its function is to rapidly disintegrate and disperse the hydrogen-producing core during particle dissolution, increase the contact area between the hydrogen donor and water, and promote rapid and complete hydrolysis.

[0010] The hydrogen production rate regulator is one or more of citric acid, tartaric acid, and potassium dihydrogen phosphate. Its function is to provide a weakly acidic microenvironment to regulate the hydrolysis reaction rate of the hydrogen donor, so that hydrogen is released steadily and fully within a stirring time of 3-10 minutes, avoiding both excessively rapid reaction leading to hydrogen boiling and escape, and excessively slow reaction leading to insufficient concentration.

[0011] The fast-dissolving controlled-release coating layer contains the following raw materials in parts by weight: 15-35 parts polyvinyl alcohol, 20-40 parts polyethylene glycol, 5-15 parts sodium alginate, and 1-5 parts surfactant.

[0012] Polyvinyl alcohol and sodium alginate are both film-forming materials that dissolve rapidly in water. When combined, they can completely dissolve within 3 to 8 minutes after the particles are added to water, releasing the hydrogen-producing core.

[0013] Polyethylene glycol, as a plasticizer and hydrophilic modifier, can regulate the dissolution rate of the coating layer, allowing the particles to maintain their integrity after short-term storage, but still dissolve rapidly in water.

[0014] Nonionic surfactants (such as fatty alcohol polyoxyethylene ether) are selected as surfactants. Their function is to reduce the surface tension of the solution during the particle dissolution process, so that the hydrogen bubbles are refined and evenly dispersed, and the loss of large bubbles rising rapidly to the liquid surface and escaping is reduced.

[0015] The mass ratio of the hydrogen-producing core to the rapidly dissolving controlled-release coating layer is 1:(0.08~0.25).

[0016] When the mass ratio is less than 0.08, the coating layer is too thin, the particles are easily broken during storage and handling, and the hydrogen-producing core is exposed too quickly after entering water, resulting in a concentrated release of hydrogen gas. When the mass ratio is higher than 0.25, the coating layer is too thick, and the dissolution time is extended to more than 10 minutes, which affects the ease of use of the solution. In addition, too much coating material will affect the concentration of the effective ingredients in the spray solution.

[0017] The leaf affinity modifier is selected from one or more of modified chitosan, polyglutamic acid, and betaine, and the amount added is 1% to 8% of the total weight of the raw materials of the fast-dissolving controlled-release coating layer.

[0018] After the granules dissolve, the leaf affinity modifier enters the hydrogen-rich water spray solution and performs the following multiple functions: Modified chitosan carries positively charged amino groups, which can electrostatically adsorb onto the negatively charged cuticle layer on the surface of plant leaves, prolonging the residence time of hydrogen-rich water droplets on the leaf surface and reducing droplet roll-off loss. Polyglutamic acid has excellent moisturizing properties and can form a very thin moisturizing film on the leaf surface, slowing down the droplet evaporation rate and prolonging the effective time for hydrogen to be absorbed by the leaves. Betaine is a natural osmotic regulator in plants. Exogenous betaine can be absorbed through leaves and directly participate in plant osmotic regulation, playing a synergistic role with hydrogen in drought resistance. At the same time, betaine is amphiphilic, which can further reduce the surface tension of the spray solution.

[0019] Leaf affinity modifiers are fundamentally different from traditional surfactants: traditional surfactants only improve spreadability by reducing surface tension, while the leaf affinity modifiers of this application have multiple functions such as electrostatic adsorption, moisturizing, and penetration regulation.

[0020] Further, the mass ratio of the hydrogen-producing core to the rapidly dissolving controlled-release coating layer is 1:(0.12~0.20). The leaf affinity modifier is preferably a mixture of modified chitosan and betaine, with a weight ratio of 1:(0.3~0.8).

[0021] The second objective of this invention is to provide a preparation method comprising the following steps: The hydrogen donor is pretreated under an inert atmosphere: the hydrogen donor and coating material are mixed in an inert atmosphere at a mass ratio of 1:(0.03~0.10), and heat-treated at 50~80℃ for 15~40 min to form a protective film on the surface of the hydrogen donor. The hydrogen donor readily reacts with moisture and oxygen in the air, resulting in poor storage stability. Forming a paraffin or fatty acid coating on its surface can effectively isolate it from air moisture during subsequent processing and product storage. However, this protective film can be rapidly emulsified and destroyed by surfactants upon immersion in water, without affecting the hydrogen production rate. The coating material is one or more of paraffin wax, stearic acid, and palmitic acid.

[0022] (2) The pretreated hydrogen donor is mixed evenly with the permeation dispersant, binder and hydrogen production rate regulator, and then wetted with anhydrous ethanol and granulated. The granules are then dried under vacuum at 40~55℃ to obtain the hydrogen production core.

[0023] (3) Dissolve the raw materials of the fast-dissolving controlled-release coating layer and the leaf surface affinity modifier in an ethanol aqueous solution with a volume fraction of 40%~60% to prepare a coating solution.

[0024] (4) Place the hydrogen-producing core in a fluidized bed and spray it with coating liquid under the conditions of air inlet temperature of 35~50℃ and spray pressure of 0.1~0.3 MPa. The coating weight gain is 8%~25%, and it is obtained after drying.

[0025] Furthermore, in step (4), the coating process is carried out in two stages: the first coating increases the weight by 4% to 10%, forming the inner quick-dissolving layer; after drying at room temperature for 8 to 15 minutes, a second coating is performed to increase the weight by 4% to 15%, forming the outer controlled-release protective layer. The layered coating is characterized by: the inner quick-dissolving layer containing a high proportion of polyethylene glycol and surfactants to ensure rapid disintegration of the particles after they are immersed in water; and the outer controlled-release protective layer containing a high proportion of polyvinyl alcohol and sodium alginate to provide mechanical protection and storage stability for the particles before use.

[0026] The third objective of this invention is to provide an application method comprising the following steps: (1) Add the solid hydrogen-producing particles to irrigation water at a mass ratio of 1:100~500, stir or shake for 3~10 minutes to fully dissolve the particles and release hydrogen gas, and prepare a hydrogen-rich water spray solution with a hydrogen concentration of 1.0~4.0 mg / L.

[0027] (2) Immediately spray the hydrogen-rich water spray solution prepared in step (1) onto the surface of plant leaves. The amount of spray should be such that both sides of the leaves are evenly moistened and no droplets fall.

[0028] (3) Spray once every 7 to 10 days, and use it 2 to 3 times consecutively.

[0029] Furthermore, the mass ratio of the solid hydrogen-producing particles to the irrigation water is preferably 1:(150~300).

[0030] Under the above ratios, the hydrogen concentration of the prepared hydrogen-rich water spray solution is 2.0~3.5 mg / L, which is the optimal concentration range for hydrogen-rich water to exert its drought-resistant effect on most plants. If the mass ratio is too high (>1:100), the hydrogen concentration will be too high, which may lead to excessive closure of leaf stomata or mild oxidative stress; if the mass ratio is too low (<1:500), the hydrogen concentration will be too low, and the drought-resistant effect will not be significant.

[0031] Furthermore, the preferred environmental conditions for spraying are: light intensity ≤ 800 μmol·m⁻²·s⁻¹, air temperature 15~28℃, and relative humidity ≥ 50%.

[0032] Under the above environmental conditions, the stomata of plant leaves are moderately open, the evaporation rate of the spray solution is slow, and the hydrogen bubbles remain in the droplets for a longer time, which is conducive to the full absorption of hydrogen by the leaves. Conversely, spraying under conditions of strong midday sunlight (light intensity typically >1200 μmol·m⁻²·s⁻¹), high temperature (air temperature >32℃), and low humidity (relative humidity <30%) results in excessively rapid droplet evaporation, significant hydrogen loss, and a substantial decrease in leaf absorption efficiency. Furthermore, at high temperatures, stomata tend to close, which is not conducive to hydrogen entering the leaf tissue. If it rains within 6 hours after spraying, a second spraying is necessary to ensure an effective amount of hydrogen is applied.

[0033] Furthermore, the first application should be done 3 to 7 days before the plant is subjected to drought stress, or at the early stage of drought stress (such as when the soil moisture content drops to 50% to 60% of field capacity).

[0034] Due to the adoption of the above technical solution, the beneficial effects of the present invention are: (1) The particles of this application completely dissolve and release hydrogen within 3 to 10 minutes, realizing the immediate use of hydrogen-rich water for foliar spraying; through the introduction of a leaf affinity modifier, the spreadability, retention time and moisturizing effect of the spray solution on the leaf surface are significantly improved. Combined with experimental data, it is shown that the droplet retention time of the spray solution containing the leaf affinity modifier on the leaf surface is more than twice longer than that of ordinary hydrogen-rich water, and the hydrogen absorption rate of the leaves is increased by 40% to 60%.

[0035] (2) Compared with root application, foliar spraying allows hydrogen to act directly on the stomata and photosynthetic apparatus of the leaves, avoiding the loss of hydrogen in the soil and consumption by microorganisms. The effective utilization rate of hydrogen in the spray solution of this application can reach 60%~80%, which is 3~5 times that of soil burial method.

[0036] (3) This application uses magnesium hydride as a hydrogen donor. The hydrolysis products are magnesium hydroxide and hydrogen gas, which are non-corrosive to the leaves. The hydrogen donor pretreatment and layer coating process give the product excellent storage stability. It can be stored in a sealed container for a long time. When using it, you can open the package and dissolve it in water. The operation is simple. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] The technical solution of the present invention will be further described in detail below with reference to specific preparation examples, embodiments, comparative examples, and blank control groups.

[0039] Preparation example of solid hydrogen-generating particles Preparation Example 1: (1) Pretreatment of hydrogen donor: In an argon-filled glove box, 50 g of magnesium hydride powder (200 mesh) and 3 g of paraffin were added to a sealed container and mixed. The mixture was heated and stirred at 70°C for 25 min in an argon atmosphere containing 0.5% oxygen by volume, so that the paraffin melted and formed a protective film on the surface of the magnesium hydride particles. After cooling, the pretreated magnesium hydride powder was obtained by sieving.

[0040] (2) Granulation of hydrogen-producing core: Take 50 g of pretreated magnesium hydride powder, 15 g of nano-silica, 8 g of microcrystalline cellulose and 5 g of citric acid, mix them thoroughly and evenly, add an appropriate amount of anhydrous ethanol to wet and make a soft material, granulate by extrusion and rounding, and sieve out particles with a particle size of 2.5 mm. Dry in vacuum at 50℃ for 2 hours to obtain hydrogen-producing core.

[0041] (3) Preparation of coating solution: Dissolve 25 g of polyvinyl alcohol, 30 g of polyethylene glycol, 10 g of sodium alginate, 3 g of fatty alcohol polyoxyethylene ether, 3 g of modified chitosan and 1.5 g of betaine in 500 mL of 50% ethanol aqueous solution to prepare coating solution.

[0042] (4) Layered Coating: The hydrogen-producing core was placed in a fluidized bed coating machine, with the inlet air temperature controlled at 42℃ and the spray pressure at 0.2MPa. The coating liquid was sprayed in for the first coating, resulting in a 7% weight gain. Spraying was stopped, and the core was dried at room temperature for 12 minutes. Then, a second coating was performed, resulting in an 8% weight gain and a total weight gain of 15%, meaning the mass ratio of the hydrogen-producing core to the rapidly soluble controlled-release coating layer was 1:0.15. The core was dried at 45℃ for 3 hours, and after sieving, solid hydrogen-producing particles with a particle size of approximately 2.8 mm were obtained.

[0043] Comparative Example 1 (without leaf affinity modifier) The preparation steps for this comparative example are the same as those for Preparation Example 1, except that no modified chitosan and betaine are added to the coating solution in step (3).

[0044] Comparative Example 2 (without hydrogen donor pretreatment) The preparation steps for this comparative example are the same as those for Preparation Example 1, except that: in step (1), magnesium hydride is not pretreated with paraffin coating.

[0045] Comparative Example 3 (without hydrogen production rate regulator) The preparation steps are the same as in Preparation Example 1, except that citric acid is not added in step (2).

[0046] Comparative Example 4 (Coating layer too thin) The preparation steps are the same as in Preparation Example 1, except that in step (4), the total coating weight gain is reduced to 5%, that is, the mass ratio of the hydrogen-producing core to the coating layer is 1:0.05.

[0047] Comparative Example 5 (excessively thick coating layer) The preparation steps are the same as in Preparation Example 1, except that in step (4), the total coating weight gain is increased to 30%, that is, the mass ratio of the hydrogen-producing core to the coating layer is 1:0.30.

[0048] Comparative Example 6 (Conventional electrolytic hydrogen-rich water spraying) Saturated hydrogen-rich water (hydrogen concentration 1.5 mg / L) was prepared using a commercially available electrolytic hydrogen-rich water generator, and no additives were added before spraying.

[0049] Product performance testing experiment 1. Dissolution rate and hydrogen-rich water preparation test Take 5 g of each of the solid hydrogen-producing particles from Preparation Example 1 and Comparative Examples 1-5, add them to 1 L of deionized water (25°C), stir at the same rate, and measure the time and peak concentration of hydrogen in the water. Repeat each group 3 times and take the average value.

[0050] Table 1. Dissolution hydrogen production performance of different solid hydrogen-producing particles Preparation Example 1 5.5±0.5 3.2±0.2 mg / L 1.8±0.2 mg / L Completely dissolved Comparative Example 1 5.2±0.5 3.3±0.2 mg / L 1.9±0.2 mg / L Completely dissolved Comparative Example 2 4.5±0.6 2.8±0.3 mg / L 1.6±0.3 mg / L Completely dissolved Comparative Example 3 3.2±0.4 3.8±0.3 mg / L 3.0±0.3 mg / L Completely dissolved, with bubbling and boiling. Comparative Example 4 4.0±0.4 3.5±0.2 mg / L 2.5±0.3 mg / L Completely dissolved Comparative Example 5 12.5±1.0 2.2±0.2 mg / L 0.6±0.2 mg / L Some undissolved 2. Leaf retention performance test of spray solution The hydrogen-rich water spray solution (particle to water mass ratio 1:200) prepared in Preparation Example 1 and Comparative Example 1, as well as the electrolyzed hydrogen-rich water in Comparative Example 6, were sprayed onto the surface of tomato leaves, and the complete evaporation time of the droplets on the leaf surface was measured.

[0051] Table 2. Residue time of different spray solutions on tomato leaf surface Preparation Example 1 28.5±2.5a 162.9 Comparative Example 1 21.2±2.0b 121.1 Comparative Example 6 (Electrolysis of Hydrogen-Rich Water) 17.5±1.8c 100.0 3. Storage stability test The solid hydrogen-producing particles prepared in Example 1 and Comparative Example 2 were sealed and packaged separately, and stored for 60 days at a temperature of 40°C and a relative humidity of 60% to test their hydrogen production performance.

[0052] Table 3 Comparison of Storage Stability 0 days 3.2±0.2 mg / L 2.8±0.3 mg / L 30 days 3.1±0.2 mg / L 2.1±0.3 mg / L 60 days 3.0±0.2 mg / L 1.3±0.2 mg / L 60-day decay rate 6.3% 53.6% III. Plant Drought Resistance Application Experiments Blank control group: Normal watering, no drought stress.

[0053] Drought control group: under drought stress, no spraying treatment was given.

[0054] Comparative Example 6 (Traditional Electrolytic Hydrogen-Rich Water Spray): Electrolytic hydrogen-rich water was sprayed once every 7 days for 3 consecutive times.

[0055] Comparative Example 7 (Solid Hydrogen-Generating Particles Buried in Soil): The solid hydrogen-generating particles prepared in Example 1 were buried in the rhizosphere soil at an amount equivalent to that applied by spraying, under the same drought stress conditions as in the examples. Example

[0056] Application of solid hydrogen-producing particles in drought resistance of tomato seedlings: The experimental material was tomato seedlings of the variety “Micro-Tom” at the three-leaf and one-heart stage.

[0057] Example 1: Solid hydrogen-producing particles were added to irrigation water at a mass ratio of 1:200 and stirred for 6 minutes until completely dissolved, achieving a hydrogen concentration of 3.0 mg / L. The first application was performed 3 days before the onset of drought stress, followed by applications every 7 days for a total of 3 applications. Drought stress was simulated using potted plants with controlled watering (soil moisture content 40%–50% field capacity, for 28 days). The environmental conditions during spraying were measured as follows: light intensity 350–550 μmol·m⁻²·s⁻¹, air temperature 18–22℃, and relative humidity 62%–75%. All parameters were measured after the treatment.

[0058] Table 4. Effects of different treatments on various indicators of tomato seedlings under drought stress. Blank control group 18.8±0.7a 3.48±0.12a 292.5±14.6a 158.5±8.5a 12.2±1.2e drought control group 13.2±0.6e 2.55±0.10e 158.5±11.5e 96.5±7.2e 28.5±1.8a Comparative Example 6 15.5±0.7d 2.92±0.10d 215.5±13.2d 128.5±7.8d 21.2±1.6c Comparative Example 7 14.8±0.7d 2.75±0.11e 188.5±12.5de 108.5±7.5de 24.5±1.7b Preparation Example 1 17.8±0.6b 3.28±0.09b 278.5±14.5b 152.5±8.2a 14.5±1.3d Example

[0059] Application of solid hydrogen-producing granules in drought resistance of cucumber seedlings: The experimental material was cucumber seedlings of variety "Jinyou 35". The application method was the same as in Example 1, with a mass ratio of solid hydrogen-producing granules to water of 1:250. The first spraying was performed at the initial stage of drought stress. Various indicators were measured after 28 days of drought stress.

[0060] Table 5. Effects of different treatments on various indicators of cucumber seedlings under drought stress. Blank control group 33.5±1.4a 29.2±1.6a 188.5±9.2a 19.2±1.2a drought control group 21.2±1.2d 16.5±1.4e 108.5±7.5e 10.5±0.9d Comparative Example 6 26.8±1.3c 22.2±1.5d 142.5±8.2d 15.2±1.0c Comparative Example 7 24.5±1.2d 19.5±1.4de 128.5±7.8d 13.2±1.1cd Preparation Example 1 31.2±1.3b 27.5±1.5b 172.5±8.5b 18.2±1.1ab Example

[0061] Application of solid hydrogen-producing granules in drought resistance of grapes: The experimental material was 2-year-old 'Xiahei' grape cuttings. The mass ratio of solid hydrogen-producing granules to water was 1:180. The first application was made 5 days before the onset of drought stress. Applications were repeated every 10 days for a total of 3 applications. Leaf parameters were measured after 40 days of drought stress.

[0062] Table 6. Effects of different treatments on various indicators of grape leaves under drought stress. Blank control group 0.822±0.014a 0.648±0.016a 182.5±9.2a 228.5±11.2a drought control group 0.708±0.016e 0.482±0.018e 105.5±7.8e 138.5±9.5e Comparative Example 6 0.758±0.015d 0.545±0.017d 145.5±8.5d 185.5±10.2d Comparative Example 7 0.738±0.015de 0.522±0.018de 128.5±8.2d 162.5±10.0de Preparation Example 1 0.805±0.013b 0.628±0.015b 175.5±9.0a 222.5±10.8b In summary: The foliar affinity modifier of this application significantly improves the leaf retention performance and drought resistance of the spray solution through a dual mechanism of physical retention and physiological synergy.

[0063] As can be seen from the data in Table 2, the complete evaporation time of the spray solution containing the leaf affinity modifier in Example 1 on the leaves was 62.9% longer than that in Comparative Example 6 (electrolysis of hydrogen-rich water).

[0064] The extended evaporation time provides a longer effective absorption window for hydrogen to enter the leaf tissue through the stomata. The results of Examples 1-3 consistently show that the drought resistance effect of Preparation Example 1 group is significantly better than that of Comparative Example 6 on all tested plants, verifying that the leaf affinity modifier is not a simple surfactant replacement, but plays a decisive role in improving the drought resistance effect of hydrogen application through a mechanism of physical retention and physiological synergy.

[0065] The hydrogen donor pretreatment, hydrogen production rate regulation, and coating layer mass ratio control in this application constitute a three-in-one system.

[0066] Analysis of the results in Tables 1 and 3 shows that the pretreatment of the hydrogen donor, by forming a paraffin protective film on the surface of magnesium hydride, effectively isolates moisture and oxygen in the air during storage, fundamentally inhibiting the slow deterioration of the hydrogen donor. This is why the hydrogen production performance of Comparative Example 2 decreased by more than half after 60 days of storage, while the hydrogen production performance of Preparation Example 1 remained basically stable.

[0067] The hydrogen production rate regulator provides a local weakly acidic microenvironment during particle dissolution, moderately accelerating the hydrolysis reaction of magnesium hydride to complete it within 5-6 minutes, while avoiding hydrogen escape caused by excessively rapid reaction. In contrast, Comparative Example 3, lacking this component, had its hydrogen production reaction completed rapidly in about 3 minutes, with a large amount of hydrogen escaping from the liquid surface in the form of bubbles, resulting in a decrease in the effective dissolved concentration.

[0068] The coating layer mass ratio determines the dissolution time window of the particles: in Comparative Example 4, the coating was too thin, causing the hydrogen-producing core to be exposed too early; in Comparative Example 5, the coating was too thick, resulting in slow dissolution. Neither of these conditions could meet the requirement of immediate use in the field. Pretreatment of the hydrogen donor, regulation of the hydrogen production rate, and coating layer quality are all indispensable and work together to form a complete quality system for solid hydrogen-producing particles.

[0069] The foliar spraying method proposed in this application is significantly superior to the soil application method in terms of absorption efficiency and ease of operation.

[0070] In the soil application method (Comparative Example 7), the hydrogen produced by the hydrolysis of solid hydrogen-producing particles in the soil needs to diffuse into the rhizosphere through the gaps between soil particles. This process involves significant losses. The dilution of soil moisture, the metabolic consumption of hydrogen by soil microorganisms, and the escape of hydrogen from the soil surface into the atmosphere all contribute to the fact that the actual amount of hydrogen reaching the root surface is far lower than the theoretical hydrogen production. However, the foliar application method used in this application allows hydrogen-rich water to directly contact the leaf surface. Hydrogen enters the leaf tissue through both stomata and the cuticle, shortening the diffusion path to the micrometer level and significantly improving absorption efficiency. In Example 1, using tomato root activity as a representative indicator, the activity of Example 1 was increased by 47.7% compared to Comparative Example 7.

[0071] From the perspective of field operation, Comparative Example 7 requires processes such as digging, burying, and covering with soil, which is labor-intensive and difficult to mechanize; while Preparation Example 1 only requires adding the granules to irrigation water, stirring and dissolving them before spraying, which is simple to operate and easy to be compatible with existing plant protection spraying equipment.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0073] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A solid hydrogen-producing particle, characterized by, It consists of a hydrogen-producing core and a rapidly soluble controlled-release coating layer covering the outside of the hydrogen-producing core; The hydrogen-producing core comprises the following raw materials in parts by weight: 40-70 parts hydrogen donor, 10-25 parts permeation dispersant, 5-15 parts binder, and 3-10 parts hydrogen production rate regulator. The fast-dissolving controlled-release coating layer comprises the following raw materials in parts by weight: 15-35 parts of polyvinyl alcohol, 20-40 parts of polyethylene glycol, 5-15 parts of sodium alginate, and 1-5 parts of surfactant. The mass ratio of the hydrogen-producing core to the rapidly dissolving controlled-release coating layer is 1:(0.08~0.25); The fast-dissolving controlled-release coating layer also contains a leaf affinity modifier, which is selected from one or more of modified chitosan, polyglutamic acid, and betaine, and the amount added is 1% to 8% of the total weight of the raw materials of the fast-dissolving controlled-release coating layer.

2. The solid hydrogen-producing particles of claim 1, wherein, The hydrogen donor is one or more of nano-silica, magnesium hydride, sodium borohydride, and calcium hydride; the penetration-promoting dispersant is one or more of modified starch and microcrystalline cellulose; and the hydrogen production rate regulator is one or more of citric acid, tartaric acid, and potassium dihydrogen phosphate.

3. The solid hydrogen-producing particles of claim 1, wherein, The mass ratio of the hydrogen-producing core to the rapidly dissolving controlled-release coating layer is 1:(0.12~0.20); The leaf affinity modifier is a mixture of modified chitosan and betaine, with a weight ratio of 1:(0.3~0.8).

4. A method for producing the solid hydrogen-producing particles according to any one of claims 1 to 3, characterized by, Includes the following steps: The hydrogen donor is pretreated under an inert atmosphere: the hydrogen donor and the coating material are mixed in an inert atmosphere at a mass ratio of 1:(0.03~0.10) and heat-treated at 50~80℃ for 15~40min to form a protective film on the surface of the hydrogen donor. The pretreated hydrogen donor is mixed evenly with the permeation-promoting dispersant, binder, and hydrogen production rate regulator. After being moistened with anhydrous ethanol, the mixture is granulated and dried under vacuum at 40-55℃ to obtain the hydrogen production core. The raw materials for the fast-dissolving controlled-release coating layer and the leaf affinity modifier are dissolved in an ethanol aqueous solution with a volume fraction of 40%~60% to prepare a coating solution. The hydrogen-producing core is placed in a fluidized bed and coated with a coating solution under the conditions of inlet air temperature of 35~50℃ and spray pressure of 0.1~0.3 MPa. The coating weight gain is 8%~25%, and the core is obtained after drying.

5. The preparation method according to claim 4, characterized in that, In step (1), the coating material is one or more of paraffin, stearic acid, and palmitic acid; the pretreatment is carried out in an inert atmosphere containing 0.1% to 1% oxygen by volume.

6. The preparation method according to claim 4, characterized in that, In step (4), the coating process is carried out in two stages: the first coating increases the weight by 4% to 10% to form the inner fast-dissolving layer; after drying at room temperature for 8 to 15 minutes, the second coating is carried out to increase the weight by 4% to 15% to form the outer controlled-release protective layer.

7. A method for improving plant drought resistance using the solid hydrogen-producing particles according to any one of claims 1-3, characterized in that, Includes the following steps: The solid hydrogen-producing particles are added to irrigation water at a mass ratio of 1:(100~500), and stirred or shaken for 3~10 minutes to fully dissolve the particles and release hydrogen gas, thereby preparing a hydrogen-rich water spray solution with a hydrogen concentration of 1.0~4.0 mg / L. Immediately spray the hydrogen-rich water spray solution prepared in step (1) onto the surface of plant leaves. The amount of spray should be such that both sides of the leaves are evenly moistened and no droplets fall. Spray once every 7 to 10 days, and repeat 2 to 3 times.

8. The method of claim 7, wherein, In step (1), the mass ratio of the solid hydrogen-producing particles to the irrigation water is 1:(150~300).

9. The method of claim 7, wherein, In step (2), the environmental conditions during spraying are: light intensity ≤ 800 μmol·m -2 ·s -1 Temperature range: 15-28℃, relative humidity: ≥50%.

10. The method of claim 7, wherein, The first application should be done 3 to 7 days before the plant is subjected to drought stress, or at the initial stage of drought stress.