A seed coating agent for enhancing drought resistance of meadow grass at seedling stage and a preparation method thereof

Abstract

The application discloses a seed coating agent for enhancing drought resistance of dactylis glomerata seedlings and a preparation method thereof, relates to the technical field of seed coating, and aims to improve the drought resistance of dactylis glomerata seeds. The seed coating agent is prepared by using a multi-layer coating agent cooperation mode. In the preparation of the inner layer coating agent, salicylic acid is added as a growth regulator for dactylis glomerata seeds to improve the drought resistance of the dactylis glomerata seeds. In the preparation of the outer layer coating agent, bentonite is modified. Firstly, the bentonite is subjected to sulfuric acid pickling and calcination to increase the pore of the bentonite and the air permeability. On this basis, sulfonic acid groups and triazole groups are further introduced into the bentonite to increase the adsorption of the modified bentonite to water in soil and the antifungal ability, and thus a comfortable environment is provided for seed germination.

Description

Technical Field

[0001] This invention relates to the field of seed treatment technology, specifically to a seed coating agent that enhances the drought resistance of oriental grass seedlings and its preparation method. Background Technology

[0002] Dactylis glomerata, one of the world's four major grasses, is primarily distributed in Sichuan, Yunnan, and Xinjiang in my country. It is not only a main grass species for artificial grassland construction in southern China but also a key reseeding species for natural grassland ecological restoration. Conventional planting often employs autumn sowing to avoid competition from weeds. However, the climate of the hilly areas in southern China is characterized by concentrated summer rainfall and frequent autumn droughts. Coupled with the increasing prevalence of autumn and winter droughts due to global climate change in recent years, the problem of declining germination rates and hindered grassland productivity growth is becoming increasingly prominent.

[0003] At the technological application level, while seed coating technology has been proven to improve plant survival rates by enhancing seedling resistance, current research largely focuses on disease control and yield enhancement for crops in arid northern regions. Systematic research targeting southern grassland species (such as orchardgrass) remains lacking. Among existing publicly available technologies, only one case has been found using penicillin soaking (patent CN102687613B) to promote orchardgrass germination. However, this technology carries the risk of environmental pollution due to antibiotic residues, making it difficult to meet the needs of green agriculture. Therefore, developing environmentally friendly seed treatment technologies and constructing an efficient orchardgrass establishment system adapted to the climatic characteristics of southern regions has become an urgent issue for overcoming the bottlenecks in regional grassland ecological restoration. Summary of the Invention

[0004] The purpose of this invention is to provide a seed coating agent that enhances the drought resistance of oriental grass seedlings and its preparation method, so as to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a seed coating agent for enhancing the drought resistance of oriental grass seedlings, having the following technical features: the seed coating agent is composed of an inner seed coating agent and an outer seed coating agent;

[0006] The inner seed coating agent is composed of salicylic acid, polyvinyl alcohol, and deionized water;

[0007] The inner seed coating agent contains 30-80 mg / L of salicylic acid, 5-10 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0008] The outer seed coating agent is composed of modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water;

[0009] The outer seed coating agent contains 25-34 wt% modified bentonite, 3-6 wt% superabsorbent polymer, 5-10 wt% polyvinyl alcohol, and the remainder is deionized water.

[0010] Furthermore, a method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings includes the following steps:

[0011] S1. Preparation of modified bentonite;

[0012] S11. Disperse bentonite in sulfuric acid solution, heat to 45-55℃, ultrasonically stir for 1-2.5h, centrifuge to separate the precipitate, wash with deionized water until neutral, protect with nitrogen atmosphere, calcine the precipitate, cool to room temperature after calcine, and collect the calcined bentonite.

[0013] S12. Disperse calcined bentonite in anhydrous ethanol, ultrasonically disperse it evenly, add KH-560 and mix evenly, continue to add deionized water, ultrasonically react in the dark for 8-18 hours, centrifuge to separate the precipitate and dry it to constant weight to obtain epoxidized bentonite.

[0014] S13. Under nitrogen atmosphere protection, 2,5-diaminobenzenesulfonic acid was added to deionized water and stirred until homogeneous. Under nitrogen atmosphere protection, 1,2,4-triazole-3-carboxylic acid was added. The temperature was raised to 85-90℃ and stirred in the dark for 4-12 hours. After removing excess solvent by rotary evaporation, aminotriazole intermediate was obtained.

[0015] S14. The aminotriazole intermediate was dispersed in dimethyl sulfoxide, boron trifluoride was added to it, and after mixing evenly, under nitrogen atmosphere protection, epoxidized bentonite was added, the temperature was raised to 75-85℃, and the reaction was ultrasonically vibrated for 4-8 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0016] S2. Preparation of seed coating agent;

[0017] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0018] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are sequentially dispersed in water and stirred evenly to prepare an outer seed coating agent.

[0019] Furthermore, in step S11, the calcination temperature is 430-450℃ and the calcination time is 2-4h.

[0020] Furthermore, in step S12, the mass ratio of calcined bentonite, KH-560, and deionized water is 10:(5-20):(3-12).

[0021] Further, in step S13, the mass ratio of 2,5-diaminobenzenesulfonic acid to 1,2,4-triazole-3-carboxylic acid is 1:(0.5-0.7) by weight.

[0022] Furthermore, in step S14, the mass ratio of the aminotriazole intermediate, boron trifluoride, and epoxide bentonite is (0.1-1.2):(0.001-0.005):10.

[0023] Furthermore, the application of a seed coating agent to enhance the drought resistance of oriental grass seedlings.

[0024] Furthermore, when the coating agent is used to coat orchardgrass seeds, the specific steps are as follows:

[0025] a. Mix the orchardgrass seeds with the inner seed coating agent, stir to cover the seed surface with a film, and dry at 30-40℃ for 3-4 hours to form an inner coating with a thickness of 0.8-1.2 mm, for later use;

[0026] b. Mix the inner-coated orchardgrass seeds with the outer coating agent, cover the seed surface with the coating again, and dry at 30-40℃ for 3-4 hours to form an outer coating with a thickness of 1-1.5 mm, thus completing the coating of orchardgrass seeds.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] To improve the drought resistance of orchardgrass seeds, this invention prepares a seed coating agent that enhances the drought resistance of orchardgrass seedlings. This invention uses a multi-layer coating agent approach. In preparing the inner coating agent, polyvinyl alcohol is used as a film-forming agent, and salicylic acid is added as a growth regulator to improve the drought resistance of orchardgrass seeds. Orchardgrass often faces autumn drought during autumn sowing. Salicylic acid can induce the synthesis of osmotic regulating substances, such as proline, in seeds, controlling seed osmotic pressure and enhancing cell water retention, thereby mitigating the inhibitory effect of drought stress on germination. Furthermore, as a natural plant metabolite, salicylic acid has the advantages of being green, pollution-free, biodegradable, and residue-free, effectively avoiding antibiotic contamination caused by penicillin seed soaking.

[0029] Based on this, the present invention also prepared an outer coating agent, in which superabsorbent resin and modified bentonite were added. Both superabsorbent resin and bentonite have extremely strong water absorption properties. However, untreated bentonite has small pores, which, while able to retain and absorb water, can severely affect various life activities of plant seeds and even germination. Therefore, the present invention modifies the bentonite. First, it is treated with sulfuric acid to dissolve some of the soluble ions, followed by high-temperature calcination to further remove residual organic matter, thereby increasing the porosity and air permeability of the bentonite. Furthermore, the present invention further uses an epoxy-containing silane coupling agent to... Bentonite modification involves introducing epoxy groups onto the surface of bentonite through hydrolysis using a silane coupling agent. An aminotriazole intermediate containing amino, sulfonic acid, and triazole groups was synthesized using 1,2,4-triazole-3-carboxylic acid and 2,5-diaminobenzenesulfonic acid as raw materials. This intermediate was then mixed with epoxidized bentonite containing epoxy groups, and the reaction between the amino and epoxy groups introduced sulfonic acid and triazole groups into the bentonite. The introduced triazole groups exhibit broad-spectrum antifungal and antibacterial effects, effectively preventing damage to orchardgrass seeds from various molds during storage. The introduced sulfonic acid groups effectively improve the hydrophilicity of bentonite, enhancing its adsorption of soil moisture and providing a comfortable environment for seed germination. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 These are the germination dynamics of the coated seeds in Example 6 and the uncoated seeds in Comparative Example 4 under 80% field water holding capacity.

[0032] Figure 2 This is a dynamic germination diagram of the coated seeds of Example 6 and the uncoated seeds of Comparative Example 4 under 50% field water holding capacity.

[0033] Figure 3 This is a bar chart showing the relative water content of leaves of coated seeds in Example 6 of the present invention and uncoated seeds in Comparative Example 4.

[0034] Figure 4 This is a bar chart showing the biomass of coated seeds in Example 6 of the present invention and uncoated seeds in Comparative Example 4. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0037] S1. Preparation of modified bentonite;

[0038] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0039] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 5 parts of KH-560 were added and mixed evenly. Then, 3 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0040] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.5 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and then remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0041] S14. By weight, 0.1 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0042] S2. Preparation of seed coating agent;

[0043] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0044] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0045] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0046] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0047] Example 2. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0048] Compared with Example 1, this example increases the amount of KH-560 and deionized water added in step S12;

[0049] S1. Preparation of modified bentonite;

[0050] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0051] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 15 parts of KH-560 were added and mixed evenly. Then, 9 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0052] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.5 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and then remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0053] S14. By weight, 0.1 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0054] S2. Preparation of seed coating agent;

[0055] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0056] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0057] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0058] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0059] Example 3. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0060] Compared with Example 2, this example increases the amount of 1,2,4-triazole-3-carboxylic acid added in step S13;

[0061] S1. Preparation of modified bentonite;

[0062] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0063] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 15 parts of KH-560 were added and mixed evenly. Then, 9 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0064] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.6 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0065] S14. By weight, 0.1 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0066] S2. Preparation of seed coating agent;

[0067] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0068] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0069] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0070] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0071] Example 4. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0072] Compared with Example 3, this example further increases the amount of 1,2,4-triazole-3-carboxylic acid added in step S13;

[0073] S1. Preparation of modified bentonite;

[0074] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0075] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 15 parts of KH-560 were added and mixed evenly. Then, 9 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0076] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.7 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and then remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0077] S14. By weight, 0.1 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0078] S2. Preparation of seed coating agent;

[0079] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0080] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0081] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0082] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0083] Example 5. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0084] Compared with Example 3, this example increases the amount of aminotriazole intermediate added in step S14;

[0085] S1. Preparation of modified bentonite;

[0086] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0087] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 15 parts of KH-560 were added and mixed evenly. Then, 9 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0088] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.6 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0089] S14. By weight, 1.2 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0090] S2. Preparation of seed coating agent;

[0091] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0092] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0093] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0094] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0095] Example 6. A method for preparing a seed coating agent to enhance the drought resistance of oriental grass seedlings, comprising the following steps:

[0096] Compared with Example 5, this example increases the amount of modified bentonite added in step S22;

[0097] S1. Preparation of modified bentonite;

[0098] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0099] S12. By weight, 10 parts of calcined bentonite were dispersed in anhydrous ethanol. After ultrasonic dispersion, 15 parts of KH-560 were added and mixed evenly. Then, 9 parts of deionized water were added. After ultrasonic reaction in the dark for 16 hours, the precipitate was separated by centrifugation and dried to constant weight to obtain epoxidized bentonite.

[0100] S13. Under nitrogen atmosphere protection, add 1 part by weight of 2,5-diaminobenzenesulfonic acid to deionized water, stir until uniformly mixed, and under nitrogen atmosphere protection, add 0.6 parts of 1,2,4-triazole-3-carboxylic acid, heat to 87°C, stir and react in the dark for 8 hours, and remove excess solvent by rotary evaporation to obtain aminotriazole intermediate.

[0101] S14. By weight, 1.2 parts of aminotriazole intermediate were dispersed in dimethyl sulfoxide, 0.001 parts of boron trifluoride were added, and after mixing evenly, under nitrogen atmosphere protection, 10 parts of epoxide bentonite were added, the temperature was raised to 80°C, and the reaction was ultrasonically vibrated for 4 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

[0102] S2. Preparation of seed coating agent;

[0103] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0104] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0105] S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0106] The outer seed coating agent contains 34 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0107] Comparative Example 1. A method for preparing a seed coating agent that enhances the drought resistance of oriental grass seedlings, comprising the following steps:

[0108] Compared with Example 1, this comparative example only used ordinary bentonite to replace the modified bentonite in the same amount;

[0109] S1. Preparation of seed coating agent;

[0110] S11. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0111] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0112] S2. Bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare the outer seed coating agent.

[0113] The outer seed coating agent contains 25 wt% modified bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0114] Comparative Example 2. A method for preparing a seed coating agent that enhances the drought resistance of oriental grass seedlings, comprising the following steps:

[0115] Compared with Example 1, this comparative example only prepared calcined bentonite;

[0116] S1. Preparation of calcined bentonite;

[0117] S11. Bentonite was dispersed in a 10wt% sulfuric acid solution, heated to 50℃, ultrasonically stirred for 2 hours, centrifuged to separate the precipitate, washed with deionized water until neutral, protected by a nitrogen atmosphere, heated to 430℃, calcined the precipitate for 2.5 hours, cooled to room temperature, and calcined bentonite was collected.

[0118] S2. Preparation of seed coating agent;

[0119] S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent;

[0120] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0121] S22. Calcined bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are dispersed in water in sequence and stirred evenly to prepare an outer seed coating agent.

[0122] The outer seed coating agent contains 25 wt% calcined bentonite, 4 wt% superabsorbent polymer, and 7 wt% polyvinyl alcohol, with the remainder being deionized water.

[0123] Comparative Example 3. A method for preparing a seed coating agent that enhances the drought resistance of oriental grass seedlings, comprising the following steps:

[0124] Compared with Example 1, this comparative example only prepared an inner coating agent;

[0125] S1. Preparation of seed coating agent;

[0126] A seed coating agent was prepared by sequentially dissolving salicylic acid, polyvinyl alcohol, and deionized water in water.

[0127] The inner seed coating agent contains 30 mg / L of salicylic acid, 7 wt% of polyvinyl alcohol, and the remainder is deionized water.

[0128] Testing: The seed coating agents prepared in Examples 1-6 and Comparative Examples 1-3 of this application were mixed with the same batch of Oryza sativa seeds and coated to obtain test samples Examples 1-6 and Comparative Examples 1-3. The specific steps are as follows:

[0129] a. Mix the orchardgrass seeds with the inner seed coating agent, stir to cover the seed surface with a film, dry at 38℃ for 3.5h to form an inner coating with a thickness of 1mm, and set aside for later use;

[0130] b. Mix the inner-coated orchardgrass seeds with the outer coating agent, cover the seed surface with the coating again, and dry at 40℃ for 4 hours to form an outer coating with a thickness of 1.2 mm, thus completing the coating of orchardgrass seeds.

[0131] Another test sample, Comparative Example 4, was set up, using the same batch of orchardgrass seeds but without coating them;

[0132] 1000 seeds of orchardgrass prepared in each of the above examples and comparative examples were taken and their germination rate and seedling rate were tested using the "Regulations for the Inspection of Crop Seeds".

[0133] The germinated seeds were then further cultured, and their seedling survival rate was tested.

[0134] Take 1000 seeds of each of the above-prepared examples and comparative examples of orchardgrass, place them in an environment of 25±2℃ and 65±2% relative humidity, and store them for 3 months to test whether mold appears on their surface.

[0135] The test results are shown in the table below;

[0136]

[0137] Pot experiments were conducted on the coated seeds of Example 6 and the uncoated seeds of Comparative Example 4. Two water levels were set: normal water supply (80% field capacity) and drought stress (50% field capacity). The seeds were sown in the soil at a depth of 0.5-1 cm. The germination rate was measured. Biomass and relative leaf water content were measured 10 days after planting.

[0138] Test results are shown Figure 1-4 .

[0139] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A seed coating agent for enhancing the drought resistance of oriental grass seedlings, characterized in that: The seed coating agent consists of an inner seed coating agent and an outer seed coating agent; The inner seed coating agent is composed of salicylic acid, polyvinyl alcohol, and deionized water; The inner seed coating agent contains 30-80 mg / L of salicylic acid, 5-10 wt% of polyvinyl alcohol, and the remainder is deionized water. The outer seed coating agent is composed of modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water; The outer seed coating agent contains 25-34 wt% modified bentonite, 3-6 wt% superabsorbent polymer, 5-10 wt% polyvinyl alcohol, and the remainder is deionized water. The method for preparing the modified bentonite includes the following steps: S11. Disperse bentonite in sulfuric acid solution, heat to 45-55℃, ultrasonically stir for 1-2.5h, centrifuge to separate the precipitate, wash with deionized water until neutral, protect with nitrogen atmosphere, calcine the precipitate, cool to room temperature after calcine, and collect the calcined bentonite. S12. Disperse calcined bentonite in anhydrous ethanol, ultrasonically disperse it evenly, add KH-560 and mix evenly, continue to add deionized water, ultrasonically react in the dark for 8-18 hours, centrifuge to separate the precipitate and dry it to constant weight to obtain epoxidized bentonite. S13. Under nitrogen atmosphere protection, 2,5-diaminobenzenesulfonic acid was added to deionized water and stirred until homogeneous. Under nitrogen atmosphere protection, 1,2,4-triazole-3-carboxylic acid was added. The temperature was raised to 85-90℃ and stirred in the dark for 4-12 hours. After removing excess solvent by rotary evaporation, aminotriazole intermediate was obtained. S14. The aminotriazole intermediate was dispersed in dimethyl sulfoxide, boron trifluoride was added, and the mixture was mixed evenly. Under a nitrogen atmosphere, epoxidized bentonite was added, the temperature was raised to 75-85℃, and the reaction was ultrasonically vibrated for 4-8 hours. The precipitate was separated by centrifugation, washed with deionized water and dried to constant weight, and ground through a 200-mesh sieve to obtain modified bentonite.

2. A method for preparing a seed coating agent for enhancing the drought resistance of oriental grass seedlings as described in claim 1, characterized in that, Includes the following steps: S1. Preparation of modified bentonite; S2. Preparation of seed coating agent; S21. Salicylic acid, polyvinyl alcohol and deionized water are dissolved in water in sequence to prepare an inner seed coating agent; S22. Modified bentonite, superabsorbent polymer, polyvinyl alcohol and deionized water are sequentially dispersed in water and stirred evenly to prepare an outer seed coating agent.

3. The seed coating agent for enhancing the drought resistance of oriental grass seedlings according to claim 1, characterized in that: In step S11, the calcination temperature is 430-450℃ and the calcination time is 2-4h.

4. The seed coating agent for enhancing the drought resistance of oriental grass seedlings according to claim 1, characterized in that: In step S12, the mass ratio of calcined bentonite, KH-560, and deionized water is 10:(5-20):(3-12).

5. The seed coating agent for enhancing the drought resistance of oriental grass seedlings according to claim 1, characterized in that: In step S13, the mass ratio of 2,5-diaminobenzenesulfonic acid to 1,2,4-triazole-3-carboxylic acid is 1:(0.5-0.7) by weight.

6. The seed coating agent for enhancing the drought resistance of oriental grass seedlings according to claim 1, characterized in that: In step S14, the mass ratio of aminotriazole intermediate, boron trifluoride, and epoxide bentonite is (0.1-1.2):(0.001-0.005):

10.

7. The application of a seed coating agent as described in claim 1 that enhances the drought resistance of oriental grass seedlings.

8. The application of the seed coating agent according to claim 7, characterized in that: When the coating agent is used to coat orchardgrass seeds, the specific steps are as follows: a. Mix the orchardgrass seeds with the inner seed coating agent, stir to cover the seed surface with a film, and dry at 30-40℃ for 3-4 hours to form an inner coating with a thickness of 0.8-1.2 mm, for later use; b. Mix the inner-coated orchardgrass seeds with the outer coating agent, cover the seed surface with the coating again, and dry at 30-40℃ for 3-4 hours to form an outer coating with a thickness of 1-1.5 mm, thus completing the coating of orchardgrass seeds.

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