A composition for promoting root development and yield increase of mixed sowing grassland and its preparation method and application

Abstract

This invention relates to a composition for promoting root development and increasing yield in mixed-sown grasslands, its preparation method, and its application. Belonging to the field of agricultural technology and plant growth regulation, it addresses the technical problem of the lack of a specific composition for mixed-sown grasslands of white clover-orchardgrass-perennial ryegrass, which fails to synergistically promote root development, improve grassland establishment success rate, and increase yield in existing technologies. The composition comprises active ingredients and inactive excipients. The active ingredients, by mass percentage, include 0.001%-0.1% brassinolide, 0.1%-5% indolebutyric acid, 0.01%-1% strigolactones, and 3%-10% trace elements. The composition formulation is selected from wettable powder, water-dispersible granules, suspension concentrate, or aqueous solution. This invention, through the combination of three plant hormones and trace elements, enhances root development and root-to-shoot ratio; activates the nutrient complementarity effect between leguminous and gramineous plants, resulting in good yield increases under mixed-sown conditions.

Description

Technical Field

[0001] This invention relates to the fields of agricultural technology and plant growth regulation technology, and in particular to a composition that promotes root development and yield increase in mixed-sown grasslands, its preparation method, and its application. Background Technology

[0002] White clover-orchardgrass-perennial ryegrass mixed grassland is a widely used high-quality, high-yield artificial grassland model in temperate regions. The nitrogen-fixing properties of legume white clover complement the high-yield characteristics of grasses like orchardgrass and perennial ryegrass, theoretically enabling stable and high yields. However, in actual production, this mixed system often suffers from low grassland establishment success rates, low early yields, poor community stability, and premature degradation due to problems such as difficulty in seedling establishment and poor root development. Currently, existing plant growth regulation programs are mostly designed for single crops, and no specific technology has yet been developed to suit this mixed grassland system.

[0003] Different crops have different characteristics and varying needs for rooting or yield enhancement, thus requiring different components in the growth regulators used. For example, indolebutyric acid (IBA), a classic auxin-type plant growth regulator, is widely used to promote plant rooting. It is often used as a single IBA preparation or in simple combinations with other auxins such as naphthaleneacetic acid (NAA), primarily for single-crop transplanting or tree cutting rooting. It is applied through methods such as seed soaking or root dipping to improve the rooting rate and survival rate of a single plant. Existing solutions are designed only for single plants and do not consider the differences in growth characteristics between legumes and grasses in mixed-sown grasslands. This fails to achieve synergistic root development in mixed-sown communities and lacks the synergistic assistance of micronutrients, resulting in limited root-promoting efficiency. For example, brassinolide products are commonly used in agricultural production to promote plant cell division and expansion, and enhance stress resistance. They are mostly designed for single crops such as rice, wheat, and vegetables, and are applied through foliar spraying to promote above-ground growth and increase crop yield. However, their regulatory effect on root development is singular, without combining with rooting regulators to form a synergistic effect. Furthermore, they are not suitable for mixed-sown grassland systems and cannot address the core growth challenges of mixed communities. In recent years, strigolactones, as novel plant hormones, have seen advancements in their compounding technology. For instance, strigolactones can be compounded with auxins and zinc fertilizers to promote wheat rooting, or brassinolides, strigolactones, and micronutrients can be compounded to increase fruit tree yields.

[0004] However, none of the above technical solutions were designed to address the differences in growth characteristics between leguminous and gramineous plants in mixed grasslands. They could not synergistically promote the root development of different plants in the mixed community, and lacked precise control over the form and content of trace elements. Therefore, they could not effectively solve the problems of seedling establishment difficulties, low early yields, and easy community degradation in mixed grasslands of white clover, orchardgrass, and perennial ryegrass. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a composition for promoting root development and increasing yield in mixed-sown grasslands, its preparation method, and its application, in order to solve the technical problem in the prior art of lacking a specific composition for mixed-sown grasslands of white clover, orchardgrass, and perennial ryegrass, which cannot synergistically promote root development in mixed-sown communities and improve grassland establishment success rate and yield.

[0006] The objective of this invention is mainly achieved through the following technical solutions: This invention provides a composition for promoting root development and increasing yield in mixed-sown grasslands, comprising active ingredients and inactive excipients, wherein the active ingredients, by mass percentage, include: brassinolide 0.001%~0.1%, indolebutyric acid 0.1%~5%, strigolactone compounds 0.01%~1%, and trace elements 3%~10%, and the inactive excipients by mass percentage are 83.9%~96.889%.

[0007] Furthermore, the brassinolide is one or more of 28-epibrassinolide, 24-epibrassinolide, and propionylbrassinolide.

[0008] Furthermore, the strigolactone compounds include natural strigolactones and strigolactone analogs, and the strigolactone analogs include one or more of rac-strigolactone, rac-GR24, GR5, and GR7.

[0009] Furthermore, the trace elements include zinc and at least two of iron, manganese, copper, boron and molybdenum, with zinc accounting for 2% to 5% of the total mass of the composition; when any one of iron, manganese, copper, boron and molybdenum is present, each of them accounts for an independent range of 0.1% to 3% of the total mass of the composition, and the total mass percentage of trace elements other than zinc does not exceed 5%.

[0010] Furthermore, the composition is in the form of a wettable powder and / or water-dispersible granules, and the inactive excipients include a dispersant, a wetting agent, a binder, and a carrier, wherein the dispersant is one or two of sodium lignosulfonate and naphthalenesulfonate formaldehyde condensate; the wetting agent is one or two of sodium dodecylbenzenesulfonate and alkylphenol polyoxyethylene ether; the binder is one or two of sodium carboxymethyl cellulose and polyvinyl alcohol; and the carrier is a mixture of silica and kaolin.

[0011] Furthermore, the composition is an aqueous solution or a suspension, and the inactive excipients include a dispersant, a wetting agent, and a carrier, wherein the dispersant is one or more of sodium lignosulfonate and polycarboxylate; the wetting agent is fatty alcohol polyoxyethylene ether; and the carrier is deionized water, which does not contain a binder.

[0012] The present invention also provides a method for preparing the above composition, comprising the following steps: S1: Take the prescribed amounts of EDTA-chelated zinc, iron, manganese, and copper, as well as soluble inorganic salts of boron and molybdenum, add them to deionized water, and stir at the first specified temperature and the first stirring speed until completely dissolved to prepare a trace element mother liquor for later use. S2: Take the prescribed amounts of brassinolide, indolebutyric acid, and strigolactone compounds, add anhydrous ethanol or propylene glycol as a co-solvent, and stir at the second specified temperature and the second stirring speed until completely dissolved to obtain a mixed mother liquor of plant hormones for later use. S3: Place the trace element mother liquor in a reaction vessel, and slowly add the plant hormone mixed mother liquor at the third stirring speed. After the addition is complete, continue stirring until the system solution is uniform and transparent. Adjust the pH value of the system to 5.5~6.5 with citric acid to obtain the active component stock solution of the composition. S4: Prepare the active component stock solution of the composition into an active component liquid or a solid active component powder of the composition according to the usage requirements; S5: The active component liquid or solid active component powder of the composition is mixed with non-active excipients and processed using agricultural formulation technology to prepare compositions of various dosage forms.

[0013] Further, in step S1, the first specified temperature is 25~30℃, the first stirring speed is 300~500 r / min, and the stirring time is 15~20 min; and / or, In step S2, the amount of co-solvent added is 5-10 times the total mass of the hormone, the second specified temperature is 25-30℃, the second stirring speed is 200-300 r / min, and the stirring time is 10-15 min; and / or, In step S3, the third stirring speed is 300-400 r / min, the dropping speed is 5-10 mL / min, and stirring continues for 20-30 min after the dropping is completed; and / or, In step S4, the vacuum drying temperature is 40~50℃ and the vacuum degree is -0.08~-0.10MPa.

[0014] The present invention also provides the application of the composition prepared by the above preparation method in a mixed grassland of white clover-orchardgrass-perennial ryegrass.

[0015] Furthermore, the application method includes one or more of the following: pre-sowing seed soaking, foliar spraying during the seedling stage, root irrigation during the seedling stage, and foliar spraying during the turf establishment stage.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention combines three plant hormones with complementary mechanisms of action—brassinolide, indolebutyric acid, and strigolactones—to synergistically promote root development in mixed-sown grassland plants from multiple dimensions, including promoting cell division, inducing adventitious root elongation, regulating lateral root germination, and optimizing the root-shoot ratio. This achieves a comprehensive root-promoting effect of "primary root elongation + lateral root propagation + root biomass accumulation," overcoming the shortcomings of single or paired combinations that only regulate a single dimension.

[0017] 2. This invention precisely combines trace elements such as zinc, iron, manganese, copper, boron, and molybdenum, limiting the zinc content to 2%-5%, and mainly using EDTA chelate form, which can form a synergistic effect with exogenous hormones, significantly improving root promotion efficiency and plant stress resistance, and making up for the shortcomings of the existing technology of simply adding hormones and lacking nutritional synergy.

[0018] 3. This invention is the first to design a mixed-sowing grassland system of white clover, orchardgrass, and perennial ryegrass. Through application methods such as seed soaking and seedling spraying, it effectively solves the problems of difficult seedling establishment, low early yield, and easy community degradation in this mixed-sowing system, improving grassland establishment success rate and early biomass, and balancing competition between legumes and grasses. The composition of this invention, in the mixed-sowing mode, can activate the nitrogen-fixing capacity of white clover and the high-yielding characteristics of orchardgrass and ryegrass, achieving nutrient complementarity and synergistic yield enhancement. Its yield-increasing effect is not a simple additive effect of a single grass species, but rather a synergistic effect of the entire mixed-sowing community.

[0019] 4. This invention employs a stepwise mixing method to prepare the active components. First, trace element stock solutions and plant hormone mixed stock solutions are prepared separately. Then, they are slowly added dropwise and mixed while adjusting the pH. This effectively avoids complexation reactions between chelated trace elements and hormones, ensuring the stability of the activity of each component. The composition can be processed into various formulations such as wettable powder, water-dispersible granules, suspension concentrates, or aqueous solutions, offering flexible application methods and compatibility with large-scale equipment such as drones and drip irrigation. It is suitable for promotion in scenarios such as the establishment of high-quality, high-yield artificial grasslands in temperate regions, improvement of existing grasslands, and grassland ecological restoration.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1This is a flowchart of the preparation method of the composition of the present invention. Detailed Implementation

[0023] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0024] This invention provides a composition for promoting root development and increasing yield in mixed-sown grasslands, comprising active ingredients and inactive excipients. The active ingredients, by mass percentage, include: brassinolide 0.001%~0.1%, indolebutyric acid 0.1%~5%, strigolactone compounds 0.01%~1%, and trace elements 3%~10%. The trace elements include zinc and at least two of iron, manganese, copper, boron, and molybdenum, with zinc accounting for 2%~5% of the total mass of the composition. When any one of iron, manganese, copper, boron, or molybdenum is present, each independently accounts for 0.1%~3% of the total mass of the composition, and the total mass percentage of trace elements other than zinc does not exceed 5%. Zinc, iron, manganese, and copper are preferably in EDTA chelated form, and boron and molybdenum are preferably in soluble inorganic salt form.

[0025] The inactive excipients are the remaining components in the composition other than the active ingredients mentioned above, including dispersants, wetting agents, binders and carriers; their mass percentage is: 100% - (mass percentage of brassinolide + mass percentage of indolebutyric acid + mass percentage of strigolactone compounds + mass percentage of trace elements), corresponding to a mass percentage range of 83.9%~96.889%.

[0026] For example, the mass percentages of brassinolide are 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.045%, 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095%, and 0.1%.

[0027] The mass percentages of indolebutyric acid are 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, and 5.0%.

[0028] The mass percentages of strigolactone compounds were 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, and 1.0%.

[0029] The mass percentages of trace elements are 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, and 10%; among which, the mass percentages of zinc are 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, and 5%.

[0030] Specifically, the brassinolide is one or more of 28-epibrassinolide, 24-epibrassinolide, and propionylbrassinolide, preferably 24-epibrassinolide, which can promote plant cell division and expansion, enhance plant stress resistance, and provide basic structural support for root growth.

[0031] Indolebutyric acid (IBA) is a potent rooting regulator that can directionally induce the formation and elongation of adventitious roots, promoting rooting of seedlings in mixed-sown grasslands during the transplanting period.

[0032] Strigolactone compounds include natural strigolactones and strigolactone analogs. The strigolactone analogs include one or more of rac-strigolactone (rac-GR24), GR5, and GR7, wherein GR5 and GR7 are synthetic strigolactone structural analogs. Natural strigolactones and the analogs can be used interchangeably. Natural strigolactones can be used alone or in combination with one or more strigolactone analogs. They can be used to precisely regulate the germination and distribution of lateral roots, inhibit apical dominance of the aboveground parts of plants, promote the allocation of more photosynthetic products to the underground roots, and optimize the root-shoot ratio.

[0033] Among micronutrients, zinc is a core component, preferentially chelated with EDTA. Its role is to form a synergistic effect with brassinolide, indolebutyric acid, and strigolactones, significantly improving root-promoting efficiency. It also participates in plant enzymatic reactions, enhancing the stress resistance (cold, drought, and stress resistance) of mixed-sown grassland plants, assisting in activating nitrogen fixation in leguminous white clover, and promoting nutrient absorption in gramineous plants. Iron is preferentially chelated with EDTA, participating in chlorophyll synthesis and photosynthesis, compensating for iron deficiency-induced chlorosis in mixed-sown grassland seedlings, ensuring normal plant growth and metabolism, and providing material support for root development and biomass accumulation. Manganese is preferentially chelated with EDTA, activating the activity of various antioxidant enzymes in plants, reducing damage from abiotic stresses, promoting carbohydrate synthesis and transport, and optimizing nutrient distribution efficiency in mixed-sown communities. Copper is preferentially used in EDTA chelated form, participating in plant respiration and protein synthesis, enhancing plant resistance to diseases and pests, improving the growth of mixed-sown grassland plants, and increasing seedling survival rates after transplanting. Boron is preferentially used in soluble inorganic salt forms such as boric acid, promoting pollen germination and fertilization, improving nitrogen fixation efficiency in white clover, while also strengthening plant cell wall toughness, reducing root damage, and promoting lateral root germination. Molybdenum is preferentially used in soluble inorganic salt forms such as ammonium molybdate, serving as an important component of nitrogenase in leguminous plants, significantly enhancing the nitrogen fixation capacity of white clover, providing sufficient nitrogen for gramineous plants, achieving nutrient complementarity in mixed-sown communities, and indirectly promoting root development and yield increase.

[0034] It should be noted that the four components of the active ingredients in this invention—brassinolide, indolebutyric acid, strigolactones, and trace elements—are not simply additive, but rather constitute a functional system adapted to the growth characteristics of mixed white clover-orchardgrass-perennial ryegrass grasslands based on multi-level synergistic effects. Specifically: Brassinolide, indolebutyric acid (IBA), and strigolactones synergistically promote root development. IBA, as a core rooting regulator, directionally induces the formation and elongation of adventitious roots in mixed-sown grassland seedlings, improving rooting efficiency in the early stages of mixed-sown grassland establishment. Strigolactones regulate lateral root germination and distribution and inhibit aboveground branching, thereby reducing nutrient consumption in the aboveground parts, promoting the allocation of photosynthetic products to the roots, increasing the root-to-shoot ratio, and compensating for the insufficient regulation of lateral root development by IBA beyond taproot elongation. Brassinolide promotes cell division and expansion, enhancing plant tolerance to adversity during the establishment period (such as temperature fluctuations and water stress), providing the cellular basis for the effects of IBA and strigolactones. The synergistic effect of these three compounds simultaneously enhances taproot elongation, lateral root propagation, and root biomass accumulation, overcoming the limitations of single or paired combinations in root regulation.

[0035] Zinc, as the core of the micronutrient system, complements three plant hormones (brassinolide, indolebutyric acid, and strigolactone compounds) in a "hormone regulation-nutrient supply" mechanism. Zinc enhances the physiological activity of the three plant hormones and improves root-promoting efficiency; iron and manganese participate in chlorophyll synthesis and photosynthetic electron transport, maintaining the plant's basal metabolic level and providing material and energy guarantees for root development under hormone regulation; boron promotes pollen germination and fertilization, maintains cell wall integrity, and reduces root damage; molybdenum, as a component of nitrogenase in legumes, improves the nitrogen-fixing efficiency of white clover, provides nitrogen for grasses, and indirectly enhances the root-promoting and yield-increasing effects of hormones; at the same time, the micronutrient system as a whole can improve plant stress resistance and reduce the inhibition of the three plant hormones' function by adverse conditions.

[0036] Within the micronutrient composition, zinc, iron, manganese, copper, boron, and molybdenum each have a clear role and work synergistically. Zinc plays a leading role in enhancing hormone activity, iron ensures photosynthetic efficiency, manganese enhances plant stress resistance, copper promotes plant respiration metabolism and protein synthesis, boron optimizes root cell wall toughness and reduces root damage, and molybdenum enhances the nitrogen-fixing capacity of white clover. The combination of each element in a limited ratio not only meets the differentiated growth needs of leguminous (white clover) and grass (orchardgrass, perennial ryegrass) plants in mixed grasslands, but also avoids growth imbalances caused by excessive or insufficient amounts of a single micronutrient. This further strengthens the synergistic effect with the three plant hormones, ensuring that the core efficacy of the composition in promoting root growth and increasing yield is maximized.

[0037] Specifically, depending on the dosage form, the type and amount of inactive excipients can be adjusted accordingly, based on the total weight of the composition: For wettable powders and / or water-dispersible granules, the dispersant is one or both of sodium lignosulfonate and naphthalene sulfonate formaldehyde condensate, wherein the mass percentage of sodium lignosulfonate is 2% to 5% (exemplarily, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%), and the mass percentage of naphthalene sulfonate formaldehyde condensate is 1% to 3% (exemplarily, 1%, 1.5%, 2%, 2.5%, 3%); the wetting agent is one or both of sodium dodecylbenzenesulfonate and alkylphenol polyoxyethylene ether, wherein the mass percentage of sodium dodecylbenzenesulfonate is 1% to 2% (exemplarily, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%), and the mass percentage of alkylphenol polyoxyethylene ether is 1% to 2%. The mass percentage of sodium carboxymethyl cellulose is 0.5% to 1.5% (exemplary, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%); the binder is one or both of sodium carboxymethyl cellulose and polyvinyl alcohol, wherein the mass percentage of sodium carboxymethyl cellulose is 0.5% to 1% (exemplary, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%) and the mass percentage of polyvinyl alcohol is 0.3% to 0.8% (0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%). The carrier is a mixture of silica and kaolin, wherein silica accounts for 5% to 15% of the total weight of the composition (exemplary, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%), and the amount of kaolin is supplemented to 100% of the total weight of the composition based on the total amount of active components and other non-active excipients.

[0038] For aqueous or suspending formulations, the dispersant is one or more of sodium lignosulfonate and polycarboxylates, wherein the mass percentage of sodium lignosulfonate is 1% to 3% (exemplary, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%), and the mass percentage of polycarboxylates is 0.5% to 2% (exemplary, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.2%, 1.4%, 1.5%, 1.6%). 1.8%, 2%); the wetting agent is fatty alcohol polyoxyethylene ether, with a mass percentage of 0.5%~1.5% (exemplary, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.2%, 1.4%, 1.5%); deionized water is used as a carrier, and ethylene glycol (2%~5% by mass, exemplary, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%) may be added as an antifreeze agent. The amount of deionized water is made up to 100% of the total weight of the composition based on the total amount of active ingredients and other inactive excipients.

[0039] It should be noted that the active ingredient is the core component in the composition that promotes root growth and increases yield. Inactive excipients (dispersants, wetting agents, binders, carriers, etc.) do not directly promote plant growth. Their role is to help the active ingredient to disperse evenly, remain stably suspended, be easy to weigh, and adhere well to the seed or leaf surface after dilution during formulation preparation, storage, and use. This allows the active ingredient to reach its target site smoothly and maintain an effective concentration. Inactive excipients ensure the operability and application effect of the active ingredient, but do not alter its physiological activity.

[0040] The present invention also provides a method for preparing the above composition, comprising the following steps: S1: Take the prescribed amounts of EDTA-chelated zinc, iron, manganese, and copper, as well as soluble inorganic salts of boron and molybdenum, add them to deionized water, and stir at the first specified temperature and the first stirring speed until completely dissolved to prepare a trace element mother liquor for later use. Specifically, the first specified temperature is 25~30℃, the first stirring speed is 300~500 r / min, and the stirring time is 15~20 min. The first specified temperature of 25~30℃ is conducive to the stable dissolution of chelated trace elements and avoids high temperature damage to the chelate structure; the stirring speed and time ensure that the components are fully dispersed.

[0041] The trace elements include zinc and at least two of iron, manganese, copper, boron and molybdenum; zinc accounts for 2% to 5% of the total mass of the composition; when any one of iron, manganese, copper, boron and molybdenum is present, each of them accounts for 0.1% to 3% of the total mass of the composition independently, and the total mass percentage of trace elements other than zinc does not exceed 5%.

[0042] S2: Take the prescribed amounts of brassinolide, indolebutyric acid, and strigolactone compounds, add anhydrous ethanol or propylene glycol as a co-solvent, and stir at the second specified temperature and the second stirring speed until completely dissolved to obtain a mixed mother liquor of plant hormones for later use. Among them, brassinolide accounts for 0.001%~0.1% of the total mass of the composition, indolebutyric acid accounts for 0.1%~5% of the total mass of the composition, and strigolactone compounds account for 0.01%~1% of the total mass of the composition.

[0043] Specifically, the amount of solubilizer added is 5 to 10 times the total mass of the three plant hormones (brassinolide, indolebutyric acid, and strigolactone compounds); the second specified temperature is 25 to 30°C, the second stirring speed is 200 to 300 r / min, and the stirring time is 10 to 15 min. The addition of the solubilizer can improve the solubility of the lipid-soluble hormones, ensuring a uniform and transparent mixed mother liquor; the second specified temperature of 25 to 30°C ensures the dissolution rate of the hormones in the solubilizer while avoiding high temperatures that could lead to hormone decomposition and inactivation; the moderate stirring speed ensures complete dissolution while preventing excessive shear force from generating bubbles or damaging the hormone molecular structure.

[0044] S3: Place the trace element mother liquor in a reaction vessel, and slowly add the plant hormone mixed mother liquor at the third stirring speed. After the addition is complete, continue stirring until the system solution is uniform and transparent. Adjust the pH value of the system to 5.5~6.5 with citric acid to obtain the active component stock solution of the composition. Specifically, the third stirring speed is 300-400 r / min. This stirring speed ensures uniform mixing of the two phases while avoiding excessively fast stirring that could cause eddies and local concentration fluctuations. The dropping speed is 5-10 mL / min, and after the dropping is completed, stirring continues for 20-30 min until the system solution is homogeneous and transparent. Slow dropping avoids excessively high local concentrations that could lead to complexation reactions between components. Maintaining a weakly acidic environment with a pH of 5.5-6.5 helps maintain the stability of chelated trace elements and prevents the precipitation of metal ions.

[0045] S4: Prepare the active component stock solution of the composition into an active component liquid or a solid active component powder of the composition according to the usage requirements; Specifically, if preparing a liquid active component, the stock solution of the active component is diluted to the target concentration with deionized water; if preparing a solid active component, the stock solution of the active component is dried under vacuum to constant weight, pulverized and passed through an 80-100 mesh sieve to obtain a solid active component powder. The vacuum drying temperature is 40-50℃, and the vacuum degree is -0.08 to -0.10 MPa. This temperature range accelerates water evaporation while preventing the degradation of heat-sensitive components such as brassinolide and strigolactones at high temperatures. This vacuum degree range significantly lowers the boiling point of water, achieving rapid drying at low temperatures, while preventing oxidation and deterioration of the material during the drying process.

[0046] S5: The active component liquid or solid active component powder of the composition is mixed with non-active excipients, and the composition is prepared by using the corresponding formulation processing method according to the required dosage form.

[0047] Specifically, for wettable powders, the process involves pulverizing, mixing, and sieving; for water-dispersible granules, the process involves pulverizing, granulating, drying, and sieving; for suspensions, the process involves high-speed shearing homogenization; and for aqueous solutions, the process involves direct stirring and volume adjustment.

[0048] The above composition is suitable for mixed-sowing grasslands of white clover, orchardgrass, and perennial ryegrass. Its application methods include one or more of the following: pre-sowing seed soaking, foliar spraying during the seedling stage, root irrigation during the seedling stage, and foliar spraying during the established stage. A combination of pre-sowing seed soaking and two foliar spraying applications during the seedling stage is preferred. Specifically, the parameters for pre-sowing seed soaking, foliar spraying during the seedling stage, root irrigation during the seedling stage, and foliar spraying during the established stage are as follows: Pre-sowing seed soaking: Dilute the composition with water 1000-2000 times, with a liquid-to-seed ratio (volume:mass) of 1.8:1-2.2:1. Soak the seeds at 20-25℃ for 4-6 hours, stirring once every hour during the soaking period. After soaking, air-dry the seeds until there is no water film on the seed surface and they do not clump together (drying time should not exceed 2 hours), and sow immediately.

[0049] Foliar spraying during the seedling stage: Dilute the composition with water 500-1000 times, add 0.1% neutral spreading agent, and apply at a rate of 30-50 liters / acre. Spray once each at the 2-3 leaf stage and the 4-5 leaf stage of the seedlings. If it rains within 4 hours after spraying, re-spray at a concentration of 50% of the original concentration.

[0050] Seedling stage root irrigation: For dry or infertile soil, foliar spraying can be used as an alternative or supplement when the seedlings have 3-4 leaves. Dilute the composition with water 500-1000 times and use drip irrigation, flushing irrigation or watering around the seedlings. The application rate is 50-80 liters / acre. Ensure that the irrigation solution penetrates to the root layer 5-10 cm deep in the soil. After irrigation, lightly hoe to reduce water evaporation.

[0051] Foliar spraying during the establishment period: After the grassland has established itself (plant height 20-30 cm), during the greening period, 3-5 days after the first mowing and 3-5 days after the second mowing, dilute the composition with water 500-1000 times and spray evenly at a rate of 30-50 liters per acre.

[0052] All applications should be carried out on sunny, windless or cloudy days, avoiding periods of high temperature and strong sunlight (before 10 a.m. or after 4 p.m.).

[0053] In one specific implementation, the application method steps include: S1: Set basic parameters for mixed-sown grassland Specifically, the weight range of white clover, orchardgrass, and perennial ryegrass seeds is suitable for the establishment of mixed grasslands: white clover seeds should account for 10%~20% of the total weight, orchardgrass seeds for 30%~40%, and perennial ryegrass seeds for 40%~60%, with a total weight of 100%. Sowing can be done by row sowing or broadcasting, with a seeding rate of 1.5~2.0 kg / mu and a sowing depth of 1~2 cm.

[0054] S2: Pre-sowing seed soaking Specifically, the composition is diluted 1000-2000 times with water and stirred evenly to prepare a soaking solution. The mixed seeds are then immersed in the soaking solution at a liquid-to-seed ratio of 1.8:1-2.2:1, preferably 2:1. The seeds are soaked at room temperature (20-25℃) for 4-6 hours, stirring once every hour during this period. After soaking, the seeds are removed and placed in a cool, ventilated place to dry until there is no water film on the seed surface and they do not clump together (drying time should not exceed 2 hours). The seeds are then sown immediately.

[0055] S3: Foliar spraying during the seedling stage Specifically, dilute the composition with water 500-1000 times, stir well, and add 0.1% neutral spreading agent (such as organosilicon) to improve the adhesion of the solution. The application rate is 30-50L / acre, and it is advisable to apply the solution evenly on both sides of the seedling leaves without dripping. Spray once when the seedlings are at the 2-3 leaf stage and once when they are at the 4-5 leaf stage. If it rains within 4 hours after spraying, re-spray in time after the rain stops, and the re-spray concentration is 50% of the original concentration.

[0056] S4: Foliar spraying during the turf establishment stage Specifically, the composition should be sprayed during the greening period after the grassland has established itself (plant height 20-30cm), 3-5 days after the first mowing, and 3-5 days after the second mowing. When spraying, dilute the composition with water 500-1000 times and spray it evenly on the leaves. The application rate is 30-50L / acre.

[0057] It should be noted that, as an alternative or supplement, for arid / poor soil plots, the composition can be applied by root irrigation when the seedlings have 3-4 leaves. When irrigating, dilute the composition with water 500-1000 times and use drip irrigation, flushing irrigation or irrigation around the seedlings. The application rate is 50-80L / acre, ensuring that the irrigation solution penetrates into the seedling root layer (the seedling root layer is about 5-10cm deep in the soil). After irrigation, lightly hoe the soil in time to reduce water evaporation.

[0058] To ensure the effectiveness of the compound application, a supporting field management system was designed based on the characteristics of the mixed-sowing grassland and implemented simultaneously with the application steps. The supporting field management measures include: deep plowing of the soil to a depth of 20-30 cm before sowing, applying 1000-1500 kg / mu of well-rotted organic fertilizer, and leveling the land; thoroughly watering the soil after soaking the seeds and sowing, maintaining a soil moisture content of 60%-70% during the seedling stage; no additional nitrogen fertilizer is needed during the seedling stage, but 10-15 kg / mu of phosphorus and potassium fertilizer can be applied at the 4-5 leaf stage; manual weeding during the seedling stage to avoid the use of herbicides.

[0059] It should be noted that all applications should be carried out on sunny, windless or cloudy days, avoiding periods of high temperature and strong sunlight (before 10:00 AM / after 4:00 PM).

[0060] The composition of this invention can be applied to mixed white clover-orchardgrass-perennial ryegrass grasslands. 60 days after sowing, the following results can be achieved: total root length ≥245cm (e.g., 245.3~286.5cm), root surface area ≥36 cm² (e.g., 36.2~42.8 cm²), root volume ≥3.0cm³ (e.g., 3.02~3.65 cm³), root-to-shoot ratio ≥0.38 (e.g., 0.38~0.42), average plant height ≥30cm (e.g., 30.5~35.2cm), aboveground biomass ≥2.3g / plant (e.g., 2.35~2.86g / plant), fresh grass yield ≥1500kg / mu (e.g., 1568.7~1856.3 kg / mu), and dry grass yield ≥270 kg / mu (e.g., 278.3~328.5 kg / mu).

[0061] The present invention will be further illustrated below with reference to specific embodiments and comparative examples. In all embodiments and comparative examples, the total weight of the composition is based on 100g.

[0062] Example 1 This embodiment provides a composition for promoting root development and increasing yield in mixed-sown grasslands, comprising active ingredients and inactive excipients. The active ingredients, by mass percentage, include: 0.05 g (0.05%) of 24-epibrassinolide, 2 g (2%) of indolebutyric acid, 0.5 g (0.5%) of the strigolactone analog rac-GR24, and 5 g (5%) of trace elements. The remainder consists of inactive excipients, including dispersants, wetting agents, binders, and carriers. The trace elements included were 3g of EDTA-chelated zinc, 1g of EDTA-chelated iron, 0.5g of EDTA-chelated manganese, 0.3g of boric acid, and 0.2g of ammonium molybdate. The inactive excipients are wettable powders, including 3g (3%) sodium lignosulfonate as a dispersant; 1.5g (1.5%) sodium dodecylbenzenesulfonate as a wetting agent; and 0.8g (0.8%) sodium carboxymethyl cellulose as a binder. The carrier is a mixture of silica and kaolin, including 10g (10%) silica, with the amount of kaolin added to make up to 100% of the total weight of the composition based on the total amount of the active components and other excipients.

[0063] The preparation method of the above composition in this embodiment includes the following steps: S1: Take the prescribed amounts of EDTA-chelated zinc, iron, manganese, and copper, as well as soluble inorganic salts of boron and molybdenum, add them to deionized water, and stir at 28℃ and 400 r / min for 18 minutes until completely dissolved to prepare a trace element mother liquor for later use. S2: Take the prescribed amounts of brassinolide, indolebutyric acid, and strigolactone compounds, add anhydrous ethanol as a co-solvent (the amount added is 6 times the total mass of the hormones), stir at 28℃ and 250r / min for 15min until completely dissolved, and prepare a mixed mother liquor of plant hormones for later use. S3: Place the trace element mother liquor in a reaction vessel, and slowly add the plant hormone mixed mother liquor dropwise at a rate of 6 mL / min while stirring at 350 r / min. After the addition is complete, continue stirring for 25 min until the system solution is uniform and transparent. Adjust the pH value of the system to 5.5~6.5 with citric acid to obtain the active component stock solution of the composition. S4: The stock solution of the active component of the composition is dried under vacuum to constant weight, then pulverized through an 80-100 mesh sieve to obtain a solid active component powder. The vacuum drying temperature is 45℃ and the vacuum degree is -0.08MPa. S5: The composition of a wettable powder is prepared by mixing the solid active component powder with the inactive excipient and processing it through an agricultural formulation process.

[0064] The above composition is applied to mixed-sowing grasslands of white clover, orchardgrass, and perennial ryegrass using a combined application method of pre-sowing seed soaking and two foliar sprays during the seedling stage. Specific application steps include: S1: Set basic parameters for mixed-sown grassland Specifically, the seed weight ratio of white clover, orchardgrass, and perennial ryegrass is 1:2:3. The seeds are sown in rows or broadcast, with a sowing rate of 1.8 kg / mu and a sowing depth of 2 cm.

[0065] S2: Pre-sowing seed soaking Specifically, dilute the composition 2000 times, stir evenly to prepare a soaking solution, immerse the mixed seeds in the soaking solution at a liquid-to-seed ratio of 2:1, soak at room temperature (20~25℃) for 5 hours, stirring once every 1 hour during the soaking period. After soaking, take out the seeds and place them in a cool and ventilated place to dry until there is no water film on the seed surface and no clumping (drying time should not exceed 2 hours), and sow immediately.

[0066] S3: Foliar spraying during the seedling stage Specifically, at the 2-3 leaf stage of seedlings, dilute the composition with water 1000 times, stir well, and add 0.1% neutral spreading agent (organosilicon) to improve the adhesion of the solution. The application rate is 30L / mu, and it is advisable to coat both sides of the seedling leaves with the solution without dripping. At the 4-5 leaf stage, dilute the composition with water 800 times, stir well, and add 0.1% neutral spreading agent (organosilicon) to improve the adhesion of the solution. The application rate is 40L / mu.

[0067] S4: Foliar spraying during the turf establishment stage Specifically, the composition should be sprayed during the greening period after the grassland has established itself (plant height 20-30cm), 3 days after the first mowing, and 3 days after the second mowing. When spraying, dilute the composition with water 800 times and spray it evenly on the leaves. The application rate is 40L / acre.

[0068] Supporting field management measures include: deep plowing of the soil to 30cm before sowing, applying 1200kg / mu of decomposed organic fertilizer, and leveling the land; watering thoroughly after sowing and maintaining soil moisture content at 70% during the seedling stage; no additional nitrogen fertilizer is needed during the seedling stage, but 12kg / mu of phosphorus and potassium fertilizer can be applied at the 4-5 leaf stage; manual weeding during the seedling stage to avoid the use of herbicides.

[0069] It should be noted that all applications should be carried out on sunny, windless or cloudy days, avoiding periods of high temperature and strong sunlight (before 10:00 AM / after 4:00 PM).

[0070] Example 2 This embodiment provides a composition for promoting root development and increasing yield in mixed-sown grasslands, comprising active ingredients and inactive excipients. The active ingredients, by mass percentage, include: 0.001 g (0.001%) of 28-epibrassinolide, 0.1 g (0.1%) of indolebutyric acid, 0.01 g (0.01%) of natural strigolactone, and 5 g (5%) of trace elements. The remainder consists of inactive excipients, including dispersants, wetting agents, binders, and carriers. The trace element composition is the same as in Example 1; the composition of inactive excipients is similar to that in Example 1, wherein the amount of kaolin is supplemented to 100% of the total weight of the composition based on the total amount of active components and other excipients, and the other inactive excipients and their contents are the same as in Example 1.

[0071] The preparation method and application of the composition are the same as in Example 1.

[0072] Example 3 This embodiment provides a composition for promoting root development and increasing yield in mixed-sown grasslands, comprising active ingredients and inactive excipients. The active ingredients, by mass percentage, include: 0.1 g (0.1%) propionyl brassinolide, 5 g (5%) indolebutyric acid, 1 g (1%) strigolactone analog GR5, and 10 g (10%) trace elements. The remainder consists of inactive excipients, including dispersants, wetting agents, binders, and carriers. The trace element composition is as follows: 5g of EDTA chelated zinc, 2g of EDTA chelated iron, 1.5g of EDTA chelated manganese, 1g of boric acid, and 0.5g of ammonium molybdate. The composition of the inactive excipients is similar to that of Example 1, except that the amount of kaolin is supplemented to 100% of the total weight of the composition based on the total amount of the active component and other excipients, and the other inactive excipients and their contents are the same as in Example 1.

[0073] The preparation method and application of the composition are the same as in Example 1.

[0074] Example 4 The composition of this embodiment is a water-dispersible granule, and the active components are exactly the same as those in Example 1; Non-reactive excipients (based on a total weight of 100g of the composition): 4g sodium lignosulfonate (dispersant), 2g naphthalenesulfonate formaldehyde condensate (dispersant), 1.5g sodium dodecylbenzenesulfonate (wetting agent), 1g sodium carboxymethyl cellulose (binder), 8g silica (carrier), and kaolin as a supplement.

[0075] Preparation method: After the active components are prepared into solid active component powder according to S1~S4, they are mixed evenly with the above-mentioned excipients, and then pulverized, granulated, dried and sieved to obtain water-dispersible granules.

[0076] The application method and field management are the same as in Example 1.

[0077] Example 5 The composition of this embodiment is an aqueous solution, and the active ingredients are the same as those in Example 1 (0.05g of 24-epibrassinolide, 2g of indolebutyric acid, 0.5g of rac-GR24, and 5g of trace elements, but in liquid form).

[0078] Non-active excipients (based on a total weight of 100g of the composition): 2g sodium lignosulfonate (dispersant), 1g fatty alcohol polyoxyethylene ether (wetting agent), 3g ethylene glycol (antifreeze agent), and deionized water to make up the remainder.

[0079] Preparation method: After obtaining the stock solution of the active component of the composition according to S1~S3, without performing the drying step of S4, directly mix the stock solution with the above excipients, make up to 100g with deionized water, stir evenly, and obtain the aqueous solution.

[0080] The application method and field management are the same as in Example 1.

[0081] Example 6 The composition of this embodiment is a suspension, and the active components are: 0.03g (0.03%) of 28-epiglobrinosin lactone, 1.5g (1.5%) of indolebutyric acid, 0.3g (0.3%) of rac-GR24, and 4g of trace elements (2g of EDTA chelated zinc, 0.8g of EDTA chelated iron, 0.5g of EDTA chelated manganese, 0.4g of boric acid, and 0.3g of ammonium molybdate).

[0082] Non-reactive excipients (based on a total weight of 100g of the composition): 2g sodium lignosulfonate (dispersant), 1g polycarboxylate SP-2700 (dispersant), 1g fatty alcohol polyoxyethylene ether (wetting agent), 3g ethylene glycol (antifreeze agent), and deionized water to make up the remainder.

[0083] Preparation method: After the active components are prepared into stock solutions according to S1~S3, they are mixed with the above-mentioned excipients and homogenized by high-speed shearing to obtain a suspension.

[0084] The application method and field management are the same as in Example 1.

[0085] Example 7 This embodiment uses the exact same composition as Example 1 (wettable powder, same formulation as Example 1), but is applied to arid land (soil moisture content <40%), and the application method is changed to root irrigation.

[0086] Application method: Soak seeds before sowing as in Example 1. When seedlings have 3-4 leaves, dilute the composition 800 times with water and apply by drip irrigation at a rate of 60L / acre, ensuring that the solution penetrates to the root layer (soil depth 5-10cm).

[0087] Field management: During the seedling stage, maintain soil moisture content at 50%~60% (slightly lower than normal conditions), and the rest is the same as in Example 1.

[0088] Comparative Example 1 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0089] The active ingredients contain only 0.05g of 24-epibrassinolide and 2g of indolebutyric acid, and no strigolactones or trace elements.

[0090] Comparative Example 2 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0091] The active ingredients contain only 0.05g of 24-epibrassinolide and 0.5g of rac-GR24, and no indolebutyric acid or trace elements.

[0092] Comparative Example 3 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0093] The active ingredients contain only 2g of indolebutyric acid and 0.5g of rac-GR24, and no 24-epibrassinolide or trace elements.

[0094] Comparative Example 4 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0095] The active ingredients include 0.05g of 24-epibrassinolide, 2g of indolebutyric acid, and 0.5g of rac-GR24, with no trace elements.

[0096] Comparative Example 5 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0097] The active ingredients include 0.05g of 24-epibrassinolide, 2g of indolebutyric acid, and 5g of trace elements (the specific composition and content are the same as in Example 1), but no strigolactone.

[0098] Comparative Example 6 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0099] The active ingredients include 0.05g of 24-epibrassinolide, 0.5g of rac-GR24, and 5g of trace elements (the specific composition and content are the same as in Example 1), and it does not contain indolebutyric acid.

[0100] Comparative Example 7 This comparative example is a wettable powder formulation, with the same excipients, preparation, and application methods as in Example 1.

[0101] The active ingredients include 2g of indolebutyric acid, 0.5g of rac-GR24, and 5g of trace elements (the specific composition and content are the same as in Example 1), but no 24-epibrassinolide.

[0102] Comparative Example 8 This comparative example serves as a blank control group, treated with water.

[0103] Comparative Example 9 In this comparative example, the composition contains 0.0005 g of 24-epibrassinolide, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0104] Comparative Example 10 In this comparative example, the composition contains 0.15 g of 24-epibrassinolide, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0105] Comparative Example 11 The composition of this comparative example contains 0.05 g of indolebutyric acid, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0106] Comparative Example 12 The composition of this comparative example contains 6g of indolebutyric acid, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0107] Comparative Example 13 In this comparative example, the composition contains 0.005 g of strigolactone rac-GR24, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0108] Comparative Example 14 In this comparative example, the composition contains 1.5g of strigolactone rac-GR24, and the remaining components are the same as in Example 1. The preparation and application methods are the same as in Example 1.

[0109] Comparative Example 15 The total amount of trace elements in the composition of this comparative example is 5g, but only 1g of EDTA chelated zinc (1.5g of EDTA chelated iron, 1g of EDTA chelated manganese, 0.8g of boric acid, and 0.7g of ammonium molybdate). The remaining composition is the same as in Example 1, and the preparation and application methods are the same as in Example 1.

[0110] Comparative Example 16 The formulation of Example 1 was applied to monoculture of orchardgrass, and the seeding rate was calculated based on the proportion of orchardgrass in the mixed sowing, with a seeding rate of 0.3 kg / mu.

[0111] Comparative Example 17 The formulation of Example 1 was applied to monoculture of orchardgrass, and the seeding rate was calculated based on the proportion of orchardgrass in the mixed sowing, with a seeding rate of 0.6 kg / mu.

[0112] Comparative Example 18 The formulation of Example 1 was applied to the monoculture of perennial ryegrass, and the seeding rate was calculated based on the proportion of ryegrass in the mixed sowing, which was 0.9 kg / mu.

[0113] Comparative Example 19 This comparative example uses the exact same active and inactive excipients (wettable powder, same formulation as Example 1) as Example 1, but the preparation method is changed to simple mixing: 24-epibrassinolide, indolebutyric acid, rac-GR24, trace elements (EDTA chelated zinc, iron, manganese, boric acid, ammonium molybdate) and all excipients are added to a mixer at once and directly stirred and mixed at room temperature for 30 minutes without stepwise mixing and pH adjustment, and then pulverized and sieved. The rest is the same as in Example 1.

[0114] Comparative Example 20 This comparative example uses the exact same composition as Example 1 (wettable powder, same formulation as Example 1), but the application method is changed: no pre-sowing seed soaking is performed, and only one foliar spray is applied when the seedlings have 3-4 leaves (diluted 800 times, 40L / acre), and the rest of the field management is the same as in Example 1.

[0115] For the biomass of the examples and comparative examples, the total root length, root surface area, root volume, root-to-shoot ratio, average plant height, aboveground biomass per plant, fresh grass yield, and dry grass yield were measured at the turf establishment period (60 days after sowing). The data are the average of three replicates. The data are shown in Table 1.

[0116] Table 1. Data on the turf establishment period (60 days after sowing) for the examples and comparative examples

[0117] As can be seen from the data in Table 1, Example 1 showed the best results (total root length 286.5 cm, fresh yield 1856.3 kg / mu), while Examples 2-7 were better than the comparative examples. The compositions of Comparative Examples 1-8 lacked some components, resulting in weaker effects than Example 1. The compositions of Comparative Examples 9-15 did not meet the requirements of this invention in terms of the content of some components, leading to weaker effects than Example 1. The yield increase under the mixed-sowing mode of Example 1 was much higher than the average increase of each single-sowing method (Comparative Examples 16-18), indicating that the compositions of this invention produced a synergistic effect in the mixed-sowing system, rather than a simple superposition of the effects of a single grass species. The effects of Comparative Examples 19-20 were weaker than Example 1, indicating that the step-by-step mixing preparation method and the preferred application scheme (seed soaking + two sprayings) of this invention play an important role in achieving the technical effects; omitting or changing these steps would lead to a significant decrease in effectiveness.

[0118] The composition of this invention can be applied to mixed white clover-orchardgrass-perennial ryegrass grasslands. 60 days after sowing, the following results can be achieved: total root length ≥245cm (e.g., 245.3~286.5cm), root surface area ≥36 cm² (e.g., 36.2~42.8 cm²), root volume ≥3.0cm³ (e.g., 3.02~3.65 cm³), root-to-shoot ratio ≥0.38 (e.g., 0.38~0.42), average plant height ≥30cm (e.g., 30.5~35.2cm), aboveground biomass ≥2.3g / plant (e.g., 2.35~2.86g / plant), fresh grass yield ≥1500kg / mu (e.g., 1568.7~1856.3 kg / mu), and dry grass yield ≥270 kg / mu (e.g., 278.3~328.5 kg / mu).

[0119] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes 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.

Claims

1. A composition for promoting root development and increasing yield in mixed-sown grasslands, characterized in that, It includes active ingredients and inactive excipients. The active ingredients, by mass percentage, include: brassinolide 0.001%~0.1%, indolebutyric acid 0.1%~5%, strigolactone compounds 0.01%~1%, and trace elements 3%~10%. The inactive excipients are 83.9%~96.889% by mass.

2. The composition according to claim 1, characterized in that, The brassinolide is one or more of 28-epi-hypobrassinolide, 24-epibrassinolide, and propionylbrassinolide.

3. The composition according to claim 1, characterized in that, The strigolactone compounds include natural strigolactones and strigolactone analogs, and the strigolactone analogs include one or more of rac-strigolactone, rac-GR24, GR5, and GR7.

4. The composition according to claim 1, characterized in that, The trace elements include zinc and at least two of iron, manganese, copper, boron and molybdenum, with zinc accounting for 2% to 5% of the total mass of the composition; when any one of iron, manganese, copper, boron and molybdenum is present, each of them accounts for 0.1% to 3% of the total mass of the composition independently, and the total mass percentage of trace elements other than zinc does not exceed 5%.

5. The composition according to claim 1, characterized in that, The composition is in the form of a wettable powder and / or water-dispersible granules. The inactive excipients include a dispersant, a wetting agent, a binder, and a carrier. The dispersant is one or two of sodium lignosulfonate and naphthalenesulfonate formaldehyde condensate; the wetting agent is one or two of sodium dodecylbenzenesulfonate and alkylphenol polyoxyethylene ether; the binder is one or two of sodium carboxymethyl cellulose and polyvinyl alcohol; and the carrier is a mixture of silica and kaolin.

6. The composition according to claim 1, characterized in that, The composition is an aqueous solution or a suspension, and the inactive excipients include a dispersant, a wetting agent, and a carrier. The dispersant is one or more of sodium lignosulfonate and polycarboxylate; the wetting agent is fatty alcohol polyoxyethylene ether; and the carrier is deionized water, which does not contain a binder.

7. A method for preparing a composition that promotes root development and yield increase in mixed-sown grasslands, comprising the following steps: S1: Take the prescribed amounts of EDTA-chelated zinc, iron, manganese, and copper, as well as soluble inorganic salts of boron and molybdenum, add them to deionized water, and stir at the first specified temperature and the first stirring speed until completely dissolved to prepare a trace element mother liquor for later use. S2: Take the prescribed amounts of brassinolide, indolebutyric acid, and strigolactone compounds, add anhydrous ethanol or propylene glycol as a co-solvent, and stir at the second specified temperature and the second stirring speed until completely dissolved to obtain a mixed mother liquor of plant hormones for later use. S3: Place the trace element mother liquor in a reaction vessel, and slowly add the plant hormone mixed mother liquor at the third stirring speed. After the addition is complete, continue stirring until the system solution is uniform and transparent. Adjust the pH value of the system to 5.5~6.5 with citric acid to obtain the active component stock solution of the composition. S4: Prepare the active component stock solution of the composition into an active component liquid or a solid active component powder of the composition according to the usage requirements; S5: The active component liquid or solid active component powder of the composition is mixed with non-active excipients and processed using agricultural formulation technology to prepare compositions of various dosage forms.

8. The preparation method according to claim 7, characterized in that, In step S1, the first specified temperature is 25~30℃, the first stirring speed is 300~500 r / min, and the stirring time is 15~20 min; and / or, In step S2, the amount of co-solvent added is 5-10 times the total mass of the hormone, the second specified temperature is 25-30℃, the second stirring speed is 200-300 r / min, and the stirring time is 10-15 min; and / or, In step S3, the third stirring speed is 300-400 r / min, the dropping speed is 5-10 mL / min, and stirring continues for 20-30 min after the dropping is completed; and / or, In step S4, the vacuum drying temperature is 40~50℃ and the vacuum degree is -0.08~-0.10MPa.

9. The use of the composition according to any one of claims 1-6 or the composition prepared by the preparation method according to any one of claims 7-8 in a mixed grassland of white clover-orchardgrass-perennial ryegrass.

10. The application according to claim 9, characterized in that, The application methods include one or more of the following: pre-sowing seed soaking, foliar spraying during the seedling stage, root irrigation during the seedling stage, and foliar spraying during the turf establishment stage.

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