Low-temperature-resistant leaf fertilizer for promoting reviving and growth of alfalfa as well as preparation method and application of leaf fertilizer

Abstract

The invention discloses a low-temperature-resistant leaf fertilizer for promoting reviving and growth of alfalfa as well as a preparation method and application of the leaf fertilizer, and belongs to the technical field of crop fertilizers. The invention discloses an alfalfa leaf fertilizer capable of resisting low temperature and promoting reviving and growth. The alfalfa leaf fertilizer comprises the following components in parts by weight: 40.0-50.0 parts of phosphorus and potassium-containing macroelement components; 1.0 to 3.0 parts of a Harpin immune protein; 1.0 to 3.0 parts of chitosan oligosaccharide; 0.5 to 1.0 part of gamma-aminobutyric acid; 10.0 to 20.0 parts of amino acid; 10.0 to 20.0 parts of glucose; 0.05 to 0.10 part of a plant regulating agent; 0.06 to 0.15 part of a surfactant; and 20 to 30 parts of water. By preferably selecting various low-temperature freezing injury resistant active components and phosphorus and potassium nutrients according to a specific ratio, the low-temperature freezing injury resistant capacity of the alfalfa is improved, the problem of repairing after low-temperature freezing injury of the alfalfa is solved, growth is quickly promoted, and a synergistic absorption effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of crop fertilizers, and in particular relates to a foliar fertilizer for alfalfa that can resist low temperature and promote green growth, and a preparation method and application thereof. Background Art

[0002] Alfalfa is a crop that likes sunlight and fertilizer, and has high requirements for light and nutrients. The root system of alfalfa has weak nitrogen fixation ability during the seedling stage and after it turns green every year, and needs additional nutrient support. In my country, more than 90% of alfalfa is concentrated in the northern region, including Northeast China, North China, Xinjiang and the Inner Mongolia Plateau. However, the winter in northern my country is cold, and late spring cold snaps are frequent. In addition, most of the planting areas have problems such as poor soil and soil desertification. Alfalfa often fails to turn green on a large scale, causing serious economic losses to companies and growers.

[0003] Foliar fertilizer can be directly absorbed by plant leaves and quickly replenish the nutrients needed by plants. Especially when soil nutrients are insufficient or the root absorption capacity is limited, certain components in foliar fertilizer, such as amino acids, medium and trace elements, can improve the plant's resistance to stress, including resistance to low temperature, drought, and disease, and can promote plant growth and development, and increase yield and quality. Related studies have shown that certain foliar fertilizer ingredients can improve the cold resistance of plants. For example, the application of phosphorus and potassium fertilizers can increase the soluble reducing sugar content of alfalfa, thereby improving cold resistance. In addition, foliar fertilizers containing amino acids and medium and trace elements can also promote plant growth and development.

[0004] Although the foliar fertilizer technology for alfalfa to resist low temperature and promote green growth can improve the cold resistance of alfalfa and promote green growth to a certain extent, it also has some shortcomings and deficiencies. The effect is affected by environmental factors: the effect of foliar fertilizer is greatly affected by environmental factors such as temperature, humidity, and light; under extremely low temperature or drought conditions, the absorption and utilization efficiency of foliar fertilizer may be reduced, thus affecting its effect of promoting the green growth of alfalfa. Limited nutrient supply: Although foliar fertilizer can quickly replenish the nutrients required by plants, the amount of nutrients it supplies is relatively limited. For alfalfa, which requires a lot of nutrients, relying solely on foliar fertilizer may not meet its needs throughout the growth cycle. It is difficult to grasp the timing of application: the timing of foliar fertilizer application has a great influence on its effect. At different stages of alfalfa growth, its demand for nutrients and absorption capacity will also be different. Therefore, it is necessary to accurately judge the timing of application to ensure that foliar fertilizer can achieve the best effect. The application concentration and dosage are difficult to control: the application concentration and dosage of foliar fertilizer need to be strictly controlled to avoid excessive or insufficient nutrient supply to alfalfa. However, in actual operation, it is difficult to accurately control the application concentration and dosage due to changes in environmental conditions, crop growth conditions and other factors.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] In order to solve the technical problems in the prior art that foliar fertilizers used for cold resistance and green growth promotion of alfalfa are greatly affected by environmental factors and the application timing, application concentration and dosage are difficult to grasp, a foliar fertilizer for alfalfa to resist low temperature and promote green growth is provided, as well as a preparation method and application thereof.

[0007] The first aspect of the present invention provides a foliar fertilizer for alfalfa to resist low temperature and promote green growth, the foliar fertilizer is composed of the following components in parts by weight:

[0008] Contains 40.0-50.0 parts of phosphorus and potassium macronutrients;

[0009] Harpin immune protein 1.0-3.0 copies;

[0010] Chitosan oligosaccharide 1.0-3.0 parts;

[0011] γ-aminobutyric acid 0.5 -1.0 parts;

[0012] Amino acids 10.0 -20.0 parts;

[0013] Glucose 10.0 -20.0 parts;

[0014] Planting agent 0.05-0.10 parts;

[0015] Surfactant 0.06-0.15 parts;

[0016] 20.0-30.0 parts of water.

[0017] Preferably, a foliar fertilizer for alfalfa to resist low temperature and promote green growth is provided, wherein the foliar fertilizer is composed of the following components in parts by weight:

[0018] Contains 42.0-48.0 parts of phosphorus and potassium macronutrients;

[0019] Harpin immune protein 1.0-2.0 copies;

[0020] Chitosan oligosaccharide 1.0-2.0 parts;

[0021] γ-aminobutyric acid 0.5 -0.8 parts;

[0022] Amino acids 12.0 -18.0 parts;

[0023] Glucose 12.0 -18.0 parts;

[0024] Planting agent 0.05-0.08 parts;

[0025] Surfactant 0.09-0.12 parts;

[0026] 22.0-28.0 parts of water.

[0027] In some embodiments, the phosphorus-potassium macro-element component is compounded by phosphoric acid and potassium hydroxide, and the weight ratio of the phosphoric acid to the potassium hydroxide is 1:1-1.25.

[0028] In some embodiments, the plant regulator is selected from one of ammonium hexanoate, sodium nitrophenolate, and amine lipids, or a mixture of any two or three thereof.

[0029] In some embodiments, the surfactant is selected from one or a mixture of any two or three of rhamnolipids, sophorolipids, and trehalolipids.

[0030] The second aspect of the present invention provides a method for preparing a foliar fertilizer for alfalfa to resist low temperature and promote green growth, comprising:

[0031] Prepare an aqueous solution containing phosphorus and potassium macroelements, add glucose and amino acids, and stir to dissolve to obtain solution A;

[0032] Weigh Harpin protein, chitosan oligosaccharide, and γ-aminobutyric acid, add water and stir to dissolve, to obtain solution B;

[0033] Prepare an aqueous solution of a plant regulator to obtain a C solution;

[0034] After adjusting the pH value of the solution A to 6-7, the solution B and the solution C are added, stirred and mixed evenly, a surfactant is added, and water is added to a certain volume to obtain the foliar fertilizer. The regulator for adjusting the pH value of the solution A and the concentration of the regulator are not limited. Any general acid-base pH regulator that can adjust the pH value to 6-7 without affecting the effect of the foliar fertilizer can be used, such as citric acid, KOH with a mass fraction of 3%-5%, etc.

[0035] In some embodiments, the raw materials of the foliar fertilizer in the preparation method are composed of the following components in parts by weight:

[0036] Contains 40.0-50.0 parts of phosphorus and potassium macronutrients;

[0037] Harpin immune protein 1.0-3.0 copies;

[0038] Chitosan oligosaccharide 1.0-3.0 parts;

[0039] γ-aminobutyric acid 0.5 -1.0 parts;

[0040] Amino acids 10.0 -20.0 parts;

[0041] Glucose 10.0 -20.0 parts;

[0042] Planting agent 0.05-0.10 parts;

[0043] Surfactant 0.06-0.15 parts;

[0044] 20.0-30.0 parts of water.

[0045] In some embodiments, the phosphorus-potassium macro-element component is compounded by phosphoric acid and potassium hydroxide, and the weight ratio of the phosphoric acid to the potassium hydroxide is 1:1-1.25.

[0046] The third aspect of the present invention provides an application of the above foliar fertilizer or the foliar fertilizer prepared by the above preparation method in promoting the green growth of alfalfa against low temperature. The foliar fertilizer is used to enhance the frost resistance of alfalfa before low temperature and promote the growth of alfalfa after low temperature.

[0047] The fourth aspect of the present invention provides a cultivation method for alfalfa that resists low temperature and promotes greening growth. After the above-mentioned foliar fertilizer or the foliar fertilizer prepared by the above-mentioned preparation method is diluted with water in proportion, it is sprayed 1-2 times 1-7 days before the temperature drops sharply. When spraying twice, the interval is 2-3 days / time, and the application amount of each spraying is 100-150ml / mu; 1-2 times 1-7 days after the temperature rises, the interval is 2-3 days / time when spraying twice, and the application amount of each spraying is 100-150ml / mu.

[0048] In some embodiments, the foliar fertilizer is diluted 200-300 times before spraying.

[0049] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0050] (1) The research and development and application of foliar fertilizer for alfalfa to resist low temperature and promote greening growth are based on the physiological characteristics and growth requirements of alfalfa, as well as the role of foliar fertilizer in promoting plant growth and improving stress resistance. The present invention improves the low-temperature resistance of alfalfa by optimizing multiple low-temperature frost damage resistant active ingredients and phosphorus and potassium nutrients in a specific ratio, solves the problem of repairing alfalfa after low-temperature frost damage, and rapidly promotes growth, and has a synergistic absorption effect.

[0051] (2) Before the onset of low temperatures, phosphorus and potassium promote the opening of cells’ stomata, release of water, increase protein content, increase cell sap concentration, and lower the freezing point of cell sap to prevent damage to cell walls; phosphorus regulates stomata, inhibits evaporation, enhances plant drought resistance, and retains water; glucose and amino acids can be directly absorbed, increase cell sap concentration, and lower the freezing point; after the temperature recovers, it promotes cell repair and rapid growth; Harpin protein and chitosan oligosaccharide can induce the synthesis of proline and soluble sugars in plants, increase the freezing point of cell sap, improve the stability of cell membranes, reduce the accumulation of malondialdehyde (MDA), and improve The activity of various antioxidant enzymes; γ-aminobutyric acid (GABA) can improve the response of plant cells to adverse stress and enhance the adaptability of plants to adverse conditions, and reduce the oxidative damage caused by harmful substances such as superoxide anions and MDA; plant regulators directly promote the rapid growth of plants after low temperature frost damage; adding pure bio-based surfactants, by inhibiting the crystal growth of product solutes under low temperature conditions to play a crystal inhibition effect, increase the low temperature solubility of phosphorus, potassium and multiple components in water, and have excellent interfacial tension, it is easier to develop adsorption after foliar spraying, and at the same time, adding it in the production process has a defoaming effect. The present invention combines organic components with inorganic components, controls the proportion of each component, grasps the timing of application, and the method and dosage of application, meets the nutrient requirements and functional requirements of alfalfa low temperature frost damage, improves the ability of alfalfa to resist low temperatures, and the ability to recover growth after low temperatures, and has better economic value and higher nutritional value than alfalfa plants that are not applied with the foliar fertilizer of the present invention. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is described below by specific embodiments. It should be understood that one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combination step, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and does not limit the order of arrangement of each method or limit the scope of implementation of the present invention. The change or adjustment of the relative relationship thereof can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0053] The sources of the raw materials and instruments used in the examples are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0054] A foliar fertilizer for alfalfa to resist low temperature and promote green growth and a preparation method thereof. The raw materials of the foliar fertilizer include the following components in parts by weight:

[0055] Contains 40.0-50.0 parts of phosphorus and potassium macronutrients;

[0056] Harpin immune protein 1.0-3.0 copies;

[0057] Chitosan oligosaccharide 1.0-3.0 parts;

[0058] γ-aminobutyric acid 0.5 -1.0 parts;

[0059] Amino acids 10.0 -20.0 parts;

[0060] Glucose 10.0 -20.0 parts;

[0061] Planting agent 0.05-0.10 parts;

[0062] Surfactant 0.06-0.15 parts;

[0063] 20.0-30.0 parts of water.

[0064] The phosphorus-potassium macroelement component is compounded by phosphoric acid and potassium hydroxide, and the weight ratio of the phosphoric acid to the potassium hydroxide is 1:1-1.25;

[0065] The plant regulator is selected from one of aminoethyl hexanoate, sodium nitrophenolate, and aminoester, or a mixture of any two or three thereof; the surfactant is selected from one of rhamnolipid, sophorolipid, and trehalose lipid, or a mixture of any two or three thereof.

[0066] A method for preparing a foliar fertilizer for alfalfa to resist low temperature and promote green growth, comprising:

[0067] (1) Weigh the required phosphorus and potassium macronutrient components according to the above formula ratio, add water to slowly react and dissolve, weigh the required glucose and amino acids according to the formula ratio, add them to the above solution, stir and dissolve to obtain solution A;

[0068] (2) Weigh harpin protein, chitosan oligosaccharide, and γ-aminobutyric acid according to the above formula ratio, add water and stir to dissolve, to obtain solution B;

[0069] (3) Weigh the plant regulator according to the above formula ratio, add water and stir to dissolve, to obtain solution C;

[0070] (4) Add citric acid or 3%-5% KOH to solution A to neutralize the pH to 6-7, add solution B and solution C in order according to the formula ratio, stir and mix evenly, then add surfactant, add water to a certain volume, and package to obtain the finished product.

[0071] The following formulation examples, application methods and alfalfa growth results can be used to further illustrate the present invention, but are not meant to limit the present invention.

[0072] Example 1 and Comparative Example 1 and Comparative Example 2

[0073] The foliar fertilizer formula for alfalfa resistance to low temperature and green growth in Example 1 and the foliar fertilizer formulas of Comparative Example 1 and Comparative Example 2 are shown in Table 1.

[0074] Table 1 Foliar fertilizer formula for alfalfa resistance to low temperature and green growth in Example 1 and comparative example 1 and comparative example 2

[0075]

[0076] The preparation method of the foliar fertilizer for alfalfa to resist low temperature and re-green growth in Example 1 comprises: (1) weighing the required phosphorus and potassium macro-element components according to the formula ratio corresponding to Example 1 in Table 1, adding water to slowly react and dissolve, weighing the required glucose and amino acids according to the formula ratio, adding them to the above solution, stirring and dissolving to obtain solution A;

[0077] (2) Weigh harpin protein, chitosan oligosaccharide, and γ-aminobutyric acid according to the above formula ratio, add water and stir to dissolve, to obtain solution B;

[0078] (3) Weigh 99% of ammonium ethyl hexanoate as a plant regulator according to the above formula ratio, add water and stir to dissolve, and obtain solution C;

[0079] (4) Add 3% KOH to solution A to neutralize the pH value of solution A to 6-7, add solution B and solution C in order according to the formula ratio, stir and mix evenly, then add surfactant rhamnolipid, add water to a certain volume, and package to obtain the finished product.

[0080] Among them, in the above steps, there is no special requirement for the proportion of water used in each step, as long as it can dissolve the substance and obtain the foliar fertilizer of the required concentration.

[0081] The preparation steps of the foliar fertilizer in Comparative Examples 1 and 2 are the same as those in Example 1, except that Harpin protein, chitosan oligosaccharide, γ-aminobutyric acid, and rhamnolipid are not added in Comparative Example 1, and rhamnolipid is not added in Comparative Example 2.

[0082] Comparative Example 3

[0083] The difference between this comparative example and Example 1 is that the surfactant used is sodium dodecylbenzene sulfonate, and the rest is the same as Example 1.

[0084] Example 2

[0085] The formula of the foliar fertilizer for alfalfa to resist low temperature and promote green growth in Example 2 is shown in Table 2. The foliar fertilizer for alfalfa to resist low temperature and promote green growth is prepared according to the formula in Table 2. The preparation method is the same as that in Example 1, except that sodium nitrophenolate is used as the plant regulator.

[0086] Table 2 Foliar fertilizer formula for alfalfa to resist low temperature and promote green growth

[0087]

[0088] Example 3

[0089] The formula of the foliar fertilizer for alfalfa to resist low temperature and promote green growth in Example 3 is shown in Table 3. The foliar fertilizer for alfalfa to resist low temperature and promote green growth is prepared according to the formula in Table 3, and the preparation method is the same as that in Example 1.

[0090] Table 3 Foliar fertilizer formula for alfalfa to resist low temperature and promote green growth

[0091]

[0092]

[0093] Example 4

[0094] The formula of the foliar fertilizer for alfalfa to resist low temperature and promote greening growth in Example 4 is shown in Table 4. The foliar fertilizer for alfalfa to resist low temperature and promote greening growth is prepared according to the formula in Table 4. The preparation method is the same as that in Example 1, except that the plant regulator is amine lipid and the surfactant is trehalose lipid.

[0095] Table 4 Foliar fertilizer formula for alfalfa to resist low temperature and promote green growth

[0096]

[0097] Example 5

[0098] The formula of the foliar fertilizer for alfalfa to resist low temperature and promote greening growth in Example 5 is shown in Table 5. The foliar fertilizer for alfalfa to resist low temperature and promote greening growth is prepared according to the formula in Table 5. The preparation method is the same as that in Example 1, except that the plant regulator is amine lipid and the surfactant is trehalose lipid.

[0099] Table 5 Foliar fertilizer formula for alfalfa to resist low temperature and promote green growth

[0100]

[0101]

[0102] Foliar fertilizer stability test

[0103] The foliar fertilizer was prepared according to the method of Example 1-5 and Comparative Example 1-3, and then sealed and packaged. The fertilizer was placed at constant temperature of 0°C and 54°C for 14 days for observation. The test data were recorded as shown in Table 6:

[0104] Table 6 Status of Examples 1-5 and Comparative Examples 1-3 after storage at 0°C and 54°C

[0105] After 14 days of storage at 0℃ After 14 days of storage at 54°C Example 1 Good fluidity, no obvious changes No bloating Comparative Example 1 Good fluidity, slightly crystallized at the bottom Mild bloating Comparative Example 2 Good fluidity, slightly crystallized at the bottom Mild bloating Comparative Example 3 Slightly viscous, slightly crystallized at the bottom No bloating Example 2 Good fluidity, no obvious changes No bloating Example 3 Good fluidity, no obvious changes No bloating Example 4 Good fluidity, no obvious changes No bloating Example 5 Good fluidity, no obvious changes No bloating

[0106] It can be seen that the foliar fertilizers prepared in Examples 1-5 of the present invention have good low-temperature and high-temperature stability, good crystal inhibition performance under low temperature conditions, and no reaction between raw materials to produce gas under high temperature conditions, and also have good inhibition of the growth of microorganisms. The use of bio-based surfactants such as rhamnolipids has sterilization, crystal inhibition and defoaming functions, avoiding the tiny bubbles introduced during the production and stirring process, which are released under the influence of air pressure during storage and cause flatulence problems. In the comparative example, the viscosity is mainly caused by low temperature and reduced fluidity of the liquid; crystallization occurs because no surfactant is used in the formula or a general surfactant is used, resulting in the solute exceeding the solubility under low temperature conditions and precipitation of crystals; flatulence is mainly caused by the gas produced by the reaction between raw materials and the gas produced by the inability to inhibit the degradation of organic components by microorganisms.

[0107] Experiment on the resistance of alfalfa to low temperature and its green growth

[0108] Method for using foliar fertilizer: dilute the foliar fertilizer stock solution of Examples 1-5 and Comparative Examples 1-3 with clean water at a ratio of 1:300, spray twice before the arrival of low temperature, spray the first time 5-6 days before the arrival of low temperature, spray the second time 1-2 days before the arrival of low temperature, spray the third time 1-2 days after the arrival of low temperature, spray the fourth time 5-6 days after the arrival of low temperature, and spray 150 ml of foliar fertilizer stock solution / mu for each spray. Spraying is carried out in windy and rainless weather, and manual spraying or aerial spraying can be evenly sprayed throughout the day.

[0109] The specific operation time of Examples 1-5 and Comparative Examples 1-3 is spraying once on April 5 and April 8, the temperature is below zero in the early morning of April 9, spraying once on April 10, and spraying a second time on April 15; Comparative Example 4 is added, the foliar fertilizer formula and preparation method are consistent with Example 1, the difference is that the spraying method is different from Example 1, and the specific operation time is spraying once on April 1 and spraying once on April 20.

[0110] Through the above-mentioned planting and maintenance process, the foliage fertilizer of the present invention was tested for the influence of grade investigation, growth change after treatment, plant height, stem-leaf ratio, alfalfa yield and protein content of alfalfa after freezing injury. The test site was an alfalfa field in Alukeerqin Banner, Chifeng City, Inner Mongolia Autonomous Region. The first crop of alfalfa with uniform growth was selected, and drone spraying was carried out according to the above method. The test area was 22 mu for each variety, and it was compared with the clear water spraying. The yield statistics were fresh grass, and the crude protein in the stems and leaves of alfalfa was determined according to GB / 6432-94, using KJELTE2100 Kjeldahl automatic nitrogen determination instrument. Some weather temperature changes during the test are listed in Table 7.

[0111] Table 7 Daily temperature changes from April 1 to April 20, 2024

[0112]

[0113]

[0114] Investigation of frost damage levels and growth changes of alfalfa after treatment

[0115] The above-ground part is frozen, divided into 5 levels:

[0116] Level 1: No freezing;

[0117] Level 2: Leaf tips turn yellow due to freezing;

[0118] Level 3: The leaf tips are frozen and yellow, and half of the leaves are frozen dead;

[0119] Level 4: All leaves are dry;

[0120] Level 5: The plant or most of the tillers are frozen to death.

[0121] The survey on the damage level and growth changes of alfalfa after freezing damage are shown in Table 8.

[0122] Table 8 Investigation on damage level of alfalfa after frost damage and changes in growth after treatment

[0123]

[0124] It can be seen from the above table that the embodiments of the present invention effectively improve the low-temperature frost resistance of alfalfa, effectively solve the problem of repairing alfalfa after low-temperature frost damage, and promote the rapid growth of the plant.

[0125] Experiment on the influence of alfalfa plant height, stem-leaf ratio, alfalfa yield and protein content

[0126] The stem-to-leaf ratio of alfalfa refers to the proportional relationship between the stem and leaves of alfalfa during its growth process, specifically the ratio of the plant's stem weight to its leaf weight. It is a basic indicator for measuring the economic traits of alfalfa.

[0127] Nutritional value: The ratio of stem to leaf determines the nutritional value of alfalfa. Generally speaking, the smaller the ratio of stem to leaf, the higher the crude protein content, the lower the crude fiber content, and the higher the nutritional value. This is because the mineral and protein content in leaves is usually 1 to 1.5 times higher than that in stems, while the crude fiber content is only 1 / 3 of that in stems.

[0128] Palatability: The stem-to-leaf ratio also affects the palatability of alfalfa. A smaller stem-to-leaf ratio means richer leaves, softer forage, and better palatability. This has a positive impact on livestock feeding and digestion and absorption.

[0129] The test results of plant height, stem-to-leaf ratio, alfalfa yield and protein content of Examples 1-5 and Comparative Examples 1-4 are listed in Table 9:

[0130] Table 9 Experimental data of alfalfa plant height, stem-to-leaf yield and crude protein content

[0131] Plant height (cm) Stem-to-leaf ratio Yield (kg / mu) Crude Protein Clear water (control) 64 1.00 257 23.14％ Example 1 78 0.94 317 25.42％ Comparative Example 1 70 0.97 298 25.01％ Comparative Example 2 74 0.96 305 25.25％ Comparative Example 3 72 0.98 303 25.11％ Comparative Example 4 70 0.98 301 25.05％ Example 2 79 0.94 353 25.65％ Example 3 79 0.95 377 25.45％ Example 4 78 0.94 372 25.56％ Example 5 79 0.95 379 25.59％

[0132] After the arrival of late spring cold, alfalfa mainly shrinks, suspends growth, forms dead seedlings, and recovers slowly after low temperature. By comparing Examples 1-5 with Comparative Examples 1-4, it can be found that the foliar fertilizer and fertilization method prepared by the present invention have good low temperature resistance, combine organic components with inorganic components, control the proportion of each component, grasp the timing of application, and the method and amount of application, meet the nutrient requirements and functional requirements of low temperature frost damage of alfalfa, improve the ability of alfalfa to resist low temperature, and promote the ability of alfalfa to turn green and resume growth after low temperature. Compared with alfalfa plants not applied with the foliar fertilizer of the present invention, the foliar fertilizer has better economic value and higher nutritional value.

[0133] The research, development and application of the foliar fertilizer for resisting low temperature and promoting greening growth of alfalfa of the present invention are based on the physiological characteristics and growth requirements of alfalfa, as well as the role of the foliar fertilizer in promoting plant growth and improving stress resistance. The present invention improves the low temperature resistance of alfalfa by optimizing multiple low temperature frost damage resistant active ingredients and phosphorus and potassium nutrients in a specific ratio, solves the problem of repairing alfalfa after low temperature frost damage, and quickly promotes growth, and has a synergistic absorption effect.

[0134] Phosphorus and potassium can promote the opening of stomata of cells before the arrival of low temperatures, release water, increase protein content, increase cell sap concentration, lower the freezing point of cell sap and prevent damage to cell walls; phosphorus regulates stomata, inhibits evaporation, enhances plant drought resistance and retains water; glucose and amino acids can be directly absorbed, increase cell sap concentration and lower the freezing point; promote cell repair and rapid growth after temperature recovery; Harpin protein and chitosan oligosaccharide can induce the synthesis of proline and soluble sugars in plants, increase the freezing point of cell sap, improve the stability of cell membranes, reduce the accumulation of malondialdehyde (MDA), and improve various The activity of antioxidant enzymes; γ-aminobutyric acid (GABA) can improve the response of plant cells to adverse stress and enhance the adaptability of plants to adverse conditions, and reduce the oxidative damage caused by harmful substances such as superoxide anions and MDA; plant regulators directly promote the rapid growth of plants after low temperature frost damage; adding pure bio-based surfactants, by inhibiting the crystal growth of product solutes under low temperature conditions to play a crystal inhibition effect, increase the low temperature solubility of phosphorus, potassium and multiple components in water, and have excellent interfacial tension, it is easier to develop adsorption after foliar spraying, and at the same time, adding in the production process has a defoaming effect. The present invention combines organic components with inorganic components, controls the proportion of each component, grasps the timing of application, and the method and dosage of application, meets the nutrient requirements and functional requirements of alfalfa low temperature frost damage, improves the ability of alfalfa to resist low temperature, and the ability to recover growth after low temperature, and has better economic value and higher nutritional value than alfalfa plants that are not applied with the foliar fertilizer of the present invention.

[0135] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A foliar fertilizer for alfalfa to resist low temperature and promote green growth, characterized in that: The foliage fertilizer is composed of the following components in parts by weight: Contains 40.0-50.0 parts of phosphorus and potassium macronutrients; Harpin immune protein 1.0-3.0 copies; Chitosan oligosaccharide 1.0-3.0 parts; γ-aminobutyric acid 0.5 -1.0 parts; Amino acids 10.0 -20.0 parts; Glucose 10.0 -20.0 parts; Planting agent 0.05-0.10 parts; Surfactant 0.06-0.15 parts; 20.0-30.0 parts of water.

2. The foliar fertilizer for alfalfa to resist low temperature and promote green growth according to claim 1, characterized in that: The foliage fertilizer is composed of the following components in parts by weight: Contains 42.0-48.0 parts of phosphorus and potassium macronutrients; Harpin immune protein 1.0-2.0 copies; Chitosan oligosaccharide 1.0-2.0 parts; γ-aminobutyric acid 0.5 -0.8 parts; Amino acids 12.0 -18.0 parts; Glucose 12.0 -18.0 parts; Planting agent 0.05-0.08 parts; Surfactant 0.09-0.12 parts; 22.0-28.0 parts of water.

3. The foliar fertilizer for alfalfa to resist low temperature and promote green growth according to claim 1, characterized in that: The phosphorus-potassium macroelement component is compounded by phosphoric acid and potassium hydroxide, and the weight ratio of the phosphoric acid to the potassium hydroxide is 1:1-1.

25.

4. The foliar fertilizer for alfalfa to resist low temperature and promote green growth according to claim 1, characterized in that: The plant regulator is selected from one of ammonium ethyl hexanoate, sodium nitrophenolate and amine lipid or a mixture of any two or three thereof.

5. The foliar fertilizer for alfalfa to resist low temperature and promote green growth according to claim 1, characterized in that: The surfactant is selected from one of rhamnolipids, sophorolipids, and trehalolipids, or a mixture of any two or three thereof.

6. A method for preparing a foliar fertilizer for alfalfa to resist low temperature and promote green growth, characterized in that: include: Prepare an aqueous solution containing phosphorus and potassium macroelements, add glucose and amino acids, and stir to dissolve to obtain solution A; Weigh Harpin protein, chitosan oligosaccharide, and γ-aminobutyric acid, add water and stir to dissolve, to obtain solution B; Prepare an aqueous solution of a plant regulator to obtain a C solution; After adjusting the pH value of the solution A to 6-7, the solution B and the solution C are added, stirred and mixed evenly, a surfactant is added, and water is added to a certain volume to obtain the foliar fertilizer.

7. Application of the foliar fertilizer according to any one of claims 1 to 5 or the foliar fertilizer prepared by the preparation method according to claim 6 in promoting the growth of alfalfa against low temperature, characterized in that: The foliar fertilizer is used to enhance the frost resistance of alfalfa before low temperature and to promote the recovery of alfalfa growth after low temperature.

8. A method for cultivating alfalfa to resist low temperature and promote green growth, characterized in that: After diluting the foliar fertilizer according to any one of claims 1 to 5 or the foliar fertilizer prepared by the preparation method according to claim 6 with water in proportion, spray it 1 to 2 times 1 to 7 days before the temperature drops sharply, and when spraying twice, there is an interval of 2 to 3 days per time; spray it 1 to 2 times 1 to 7 days after the temperature rises, and when spraying twice, there is an interval of 2 to 3 days per time.

9. The cultivation method according to claim 8, characterized in that: The amount of foliar fertilizer applied each time is 100-150ml / mu.

10. The cultivation method according to claim 8, characterized in that: The foliar fertilizer was diluted 200-300 times before spraying.

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