An amino acid selenium foliar fertilizer and its preparation method

Abstract

The present invention discloses an amino acid selenium foliar fertilizer and a preparation method thereof. The amino acid selenium foliar fertilizer comprises the following raw materials in parts by mass: 30-80 parts of amino acids, 0.6-5 parts of selenium source, and 0.05-0.2 parts of sinigrin. Through the raw material combination of the foliar fertilizer, the interaction between various nutrient components, and the improvement of the foliar fertilizer preparation process, the present invention can preferably solve the problems of crop yield, quality, and foliar fertilizer absorption and utilization rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional fertilizers, and particularly relates to an amino acid selenium foliar fertilizer and a preparation method thereof. Background Technique

[0002] Selenium is one of the essential trace elements for the life activities of organisms, and has important functions such as nourishing and repairing the myocardium, scavenging free radicals in the body, delaying aging, and regulating the microcirculation system of the human body. Plant-derived organic selenium is safe, green, and efficient, and is a beneficial way for humans and animals to intake selenium. With the continuous improvement of people's living standards, people's pursuit of health is more urgent, and the demand for selenium-rich foods is also increasing.

[0003] A foliar fertilizer is a kind of top dressing outside the root. It is directly sprayed on the surface of crop leaves, absorbed by the leaves, and the nutrients are transported to various parts of the crop. It mainly plays the role of making up for the insufficient supply of nutrients by the roots, balancing the crop nutrition, or relieving the temporary shortage of supply during a certain growth period of the crop. The leaves directly absorb and utilize the available nutrients, with a relatively high utilization rate of nutrients, and at the same time, it can avoid reducing the effectiveness of certain nutrients due to the fixation of the soil on them. The absorption and transportation of nutrients by the leaves are faster than those of the roots, which is beneficial to timely meet the requirements of crop growth and development. Therefore, foliar fertilizers are often used in agriculture to quickly supplement the nutrients required by plants.

[0004] An amino acid selenium foliar fertilizer is a foliar fertilizer that contains both amino acids and selenium elements at the same time. It combines the advantages of the two nutrients and is used to improve the growth and quality of crops. However, in recent years, most of the amino acid selenium foliar fertilizers produced in China have not considered the following points when improving crop yield and quality:

[0005] (1)The nutrients sprayed on the leaf surface enter the plant through the cuticle and stomata of the leaves. However, most of the existing technologies only focus on the nutrient composition matching in foliar fertilizers and ignore the impact of the opening of plant leaf stomata on the absorption of nutrients such as amino acids and selenium, resulting in unsatisfactory fertilization effects. Although foliar fertilizers are usually sprayed under suitable external environmental conditions during daily operations to ensure appropriate leaf openings as much as possible, there are many uncertain factors in environmental conditions, and it is impossible to guarantee the suitable spraying conditions for foliar fertilizers. (2)The cuticle is the protective layer of plant leaves. The cuticle is a mixture composed of polysaccharides and lipid compounds. The nutrients applied to the leaf surface can successively penetrate through the cuticle, cell wall, and cell membrane into plant cells, and then be transported in the leaf tissue. Therefore, the affinity between the nutrients in foliar fertilizers and the cuticle is an important consideration factor. However, most of the existing technologies ignore this factor and simply rely on wetting agents to improve the wetting performance of foliar fertilizers on the leaves. This improvement effect often cannot fundamentally solve the problem of the affinity between nutrients and the leaf cuticle. (3)The preparation process of foliar fertilizers in the existing technology is relatively simple and does not consider the interaction between nutrients, resulting in low absorption rate of nutrients and low fertilizer utilization rate. (4)Environmental conditions (light conditions, temperature, etc.) will significantly affect the effect of foliar fertilization. In particular, light conditions directly affect leaf photosynthesis, making the application conditions of foliar fertilizers more stringent and bringing inconvenience to actual operations.

[0006] In summary, how to provide an amino acid selenium foliar fertilizer and its preparation method to comprehensively improve the yield, quality of crops and the absorption and utilization rate of foliar fertilizers is an urgent problem to be solved. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the existing technology and provide an amino acid selenium foliar fertilizer and its preparation method. By improving the raw material combination, the interaction between various nutrient components and the preparation process of foliar fertilizers, it can better solve the problems of crop yield, quality and the absorption and utilization rate of foliar fertilizers.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] An amino acid selenium foliar fertilizer comprises the following raw materials in parts by mass: 30 - 80 parts of amino acids, 0.6 - 5 parts of selenium source, 0.05 - 0.2 parts of sinigrin.

[0010] Preferably, the amino acid includes any one or more of aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine. More preferably, the amino acid includes any one or more of lysine, histidine, and arginine. Even more preferably, the amino acid includes lysine, histidine, and arginine in a mass ratio of 1:(0.3 - 1):(0.5 - 3).

[0011] Preferably, the selenium source includes any one or both of selenomethionine and seleno-L-cysteine. More preferably, the selenium source includes selenomethionine and seleno-L-cysteine in a mass ratio of 1:(0.3 - 5).

[0012] Preferably, the amino acid selenium foliar fertilizer further includes any one or more of 0.5 - 3 parts of an auxiliary agent, 1 - 6 parts of trace elements, 0.1 - 5 parts of nitrogen fertilizer, and 50 - 100 parts of water.

[0013] Preferably, the auxiliary agent includes one or more of polyoxyethylene sorbitan monooleate, lauryl alcohol polyoxyethylene ether, sorbitan stearate, and polyoxyethylene hydrogenated castor oil.

[0014] Preferably, the trace elements include any one or more of copper (copper sulfate), iron (ferrous sulfate), zinc (zinc sulfate), manganese (manganese sulfate), boron (borax), and molybdenum (ammonium molybdate). Even more preferably, the trace elements include iron (ferrous sulfate), zinc (zinc sulfate), boron (borax), and manganese (manganese sulfate) in a mass ratio of 1:(0.1 - 0.6):(0.1 - 1):(0.1 - 0.5).

[0015] Preferably, the nitrogen fertilizer is urea or ammonium bicarbonate.

[0016] Preferably, the amino acid selenium foliar fertilizer is in the form of an aqueous solution or a powder.

[0017] The present invention provides a method for preparing an amino acid selenium foliar fertilizer. The preparation of its aqueous solution includes the following steps: Weigh water according to the formula, and then sequentially add other raw materials in the formula (including amino acids, selenium sources, and sinigrin, and auxiliary agents, trace elements, and nitrogen fertilizers can also be added as required), and stir evenly to obtain it.

[0018] The preparation of its powder includes: Take each raw material according to the formula (including amino acids, selenium sources, and sinigrin, and auxiliary agents, trace elements, and nitrogen fertilizers can also be added as required), mix evenly, and then freeze-dry to obtain it.

[0019] Preferably, the above freeze-drying is carried out by a conventional method, and the production conditions of conventional amino acid or polypeptide lyophilized powder can be referred to, such as a temperature of -(10 - 40)°C and a vacuum degree of 10 - 30 Pa:

[0020] Preferably, the amino acid selenium foliar fertilizer further comprises 0.3 - 2 parts of an anionic surfactant.

[0021] Preferably, the anionic surfactant is disodium tocopheryl phosphate, sodium laurate, sodium oleate or sodium stearate. More preferably, the anionic surfactant is disodium tocopheryl phosphate.

[0022] Preferably, the present invention also provides a method for preparing another amino acid selenium foliar fertilizer powder, comprising the following steps:

[0023] At 30 - 50°C, mix amino acids and selenium source with water according to the formula, and adjust the pH value to 6.8 - 7.3 to obtain Solution 1. At 40 - 70°C, mix the anionic surfactant with water, and adjust the pH value to 6.0 - 6.7 to obtain Solution 2. Drop Solution 1 into Solution 2 drop by drop, and after dropping, stir at a speed of 30 - 100 r / min for 5 - 10 min to obtain a mixed solution. Spray-dry the mixed solution to obtain Powder 1. Mix other raw materials in the foliar fertilizer formula (including sinigrin, and auxiliaries, trace elements, nitrogen fertilizer can be added as required) evenly, and freeze-dry to obtain Powder 2. Mix Powder 1 and Powder 2 evenly to obtain the product.

[0024] Preferably, the water addition amount for preparing Solution 1 is 3 - 10 times the mass of the amino acids, and the water addition amount for preparing Solution 2 is 1 - 6 times the mass of the anionic surfactant.

[0025] Preferably, the spray-drying conditions are: spray pressure 0.5 - 0.8 MPa, feeding speed 0.7 - 0.9 L / h, and inlet air temperature 120 - 130°C.

[0026] The present invention also provides an application of the amino acid selenium foliar fertilizer in the planting of food crops or fruits and vegetables.

[0027] Preferably, the food crops are rice, corn, beans, potatoes, highland barley, broad beans or wheat. More preferably, the food crop is rice.

[0028] Preferably, the fruits and vegetables are vegetables or fruits.

[0029] Specifically, the vegetables are radish, Chinese cabbage, celery, leek, garlic, scallion, carrot, snake gourd, cabbage, Jerusalem artichoke, sword bean, coriander, asparagus lettuce, daylily, chili pepper, cucumber, tomato or coriander.

[0030] Specifically, the fruits are pear, apple, greengage, peach, apricot, orange, tangerine, plum, cherry, strawberry, crabapple or jujube.

[0031] The application method of the amino acid selenium foliar fertilizer is as follows: for the aqueous agent, the spraying amount is 60 - 300 g of the foliar fertilizer stock solution per mu each time. The foliar fertilizer can be directly sprayed or diluted 100 - 1000 times with water before spraying. For the powder agent, the spraying amount is 20 - 100 g of the foliar fertilizer powder per mu each time. After dissolving the foliar fertilizer powder in 1 - 3 times the amount of water, it can be directly sprayed or diluted 100 - 1000 times with water before spraying. It can be sprayed 2 - 10 times per season as needed.

[0032] The technical effects of the present invention:

[0033] 1. The foliar fertilizer of the present invention contains both amino acids and organic selenium. Amino acids can supplement nutrients, promote plant growth and metabolism, and selenium can improve the nutritional value of agricultural products. The amino acid selenium foliar fertilizer of the present invention can effectively improve the yield and quality of agricultural products and increase the selenium content in agricultural products.

[0034] 2. Sinigrin is added to the foliar fertilizer of the present invention, which has the following functions: (1) Sinigrin is a glucosinolate in cruciferous plants. After being applied to the leaf surface, it has an antibacterial effect, can reduce diseases, and promote the growth of agricultural products; (2) Sinigrin contains potassium ions. After being sprayed on the leaf surface, the potassium ions can be slowly released, improving the permeability of the leaf cell membrane, helping to increase the opening degree of leaf stomata, and promoting the absorption of the foliar fertilizer; (3) The small amount of sulfur contained in sinigrin can synergistically act with the selenium element in the foliar fertilizer to promote the absorption of selenium by agricultural products, thereby further increasing the selenium content in agricultural products.

[0035] 3. The foliar fertilizer of the present invention can be prepared into an aqueous agent or a powder agent. The present invention uses a specific method to prepare the foliar fertilizer into a powder, which can improve the dissolution and dispersion of various nutrients, significantly improve the application effect of the foliar fertilizer on the leaf surface, and help the plant leaves fully absorb nutrients.

[0036] 4. When the foliar fertilizer of the present invention is made into a powder, due to the unstable solubility of amino acids, selenium sources, etc. contained in the formula, the present invention controls the pH and first prepares Solution 1 containing amino acids and selenium sources, and adjusts the pH to 6.8 - 7.3. This pH is less than the isoelectric point of amino acids, making the amino acids carry a positive charge, and at this pH value, the carboxyl groups in the selenium source (selenomethionine Pka = 2.26, seleno-L-cysteine Pka = 5.2) dissociate hydrogen and show a negative charge. Therefore, the amino acids and selenium sources in Solution 1 can adsorb each other. Then, the present invention prepares Solution 2 containing an anionic surfactant with a pH value of 6.0 - 6.7. During the process of dropping Solution 1 into Solution 2, the anionic surfactant forms a tight adsorption with the positively charged amino acids. And because the pH value of Solution 2 is lower than that of Solution 1, when dropping Solution 1 into Solution 2, the positive charge of the amino acids is enhanced, further promoting this adsorption trend, thus forming a three-molecule layer structure of selenium source - amino acid - anionic surfactant, and then it can be spray-dried. The foliar fertilizer containing this three-molecule layer structure has better affinity with the cell structure of plant leaves, can tightly adhere to the leaf surface, and quickly penetrate the cutin layer of the leaves to transport nutrients to the inside of the leaves.

[0037] 5. In the amino acid selenium foliar fertilizer of the present invention, the anionic surfactant acts as a guiding and permeability-enhancing agent. Secondly, the connected amino acids enter the plant leaves and first play a growth-regulating role and improve leaf photosynthesis. On this basis, they absorb the selenium source, which can better ensure the absorption of selenium nutrition.

[0038] 6. In the foliar fertilizer of the present invention, the anionic surfactant is preferably sodium tocopherol phosphate, and its functions are as follows: (1) The contained tocopherol structure can not only regulate the growth and development of plants, but also has a synergistic effect with selenium. Its lipophilic structure tocopherol and hydrophilic structure phosphate both have good affinity with the plant cell membrane, and can promote the transport of foliar fertilizer nutrients within the leaf structure; (2) Generally speaking, the light conditions will affect the application effect of the foliar fertilizer. The sodium tocopherol phosphate contained in the foliar fertilizer of the present invention can also improve the adaptability of the leaves to various light conditions. Combining with the effect of sinigrin on the leaf stomata, the foliar fertilizer can have a good application effect under different light conditions; (3) In the three-molecule layer structure of selenium source - amino acid - sodium tocopherol phosphate, sodium tocopherol phosphate can act as a protective layer to protect the nutrients in the foliar fertilizer and reduce the water evaporation after spraying the foliar fertilizer, reducing the burning of the leaves due to the excessive concentration of nutrients after water evaporation. Detailed implementation mode

[0039] The above solution will be further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited by the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0040] In the following embodiments, unless otherwise specified, all raw materials are commercially available or prepared by conventional methods in the art. Example 1

[0041] This example provides an amino acid selenium foliar fertilizer, which includes the following raw materials in parts by mass: 50 parts of amino acids, 1 part of selenium source, 3 parts of trace elements, 2 parts of urea, 0.1 part of sinigrin, 1 part of auxiliary agent (polyoxyethylene hydrogenated castor oil), and 70 parts of water.

[0042] The amino acids include aspartic acid, serine, proline, glycine, methionine, isoleucine, phenylalanine, and lysine in equal parts by mass. The selenium source includes selenomethionine and seleno-L-cysteine in a mass ratio of 1:2.

[0043] The trace elements include iron (ferrous sulfate), zinc (zinc sulfate), boron (borax), and manganese (manganese sulfate) in a mass ratio of 1:0.3:0.5:0.2.

[0044] The preparation method of the amino acid selenium foliar fertilizer aqueous solution includes the following steps: Weigh water according to the formula, and then add other raw materials in the formula in sequence, and stir evenly to obtain it. Example 2

[0045] This example provides an amino acid selenium foliar fertilizer, which includes the following raw materials in parts by mass: 50 parts of amino acids, 1 part of selenium source, 3 parts of trace elements, 2 parts of urea, 0.1 part of sinigrin, 1 part of auxiliary agent (polyoxyethylene hydrogenated castor oil), and 1 part of anionic surfactant (diphosphate tocopherol).

[0046] The amino acids include lysine, histidine, and arginine in a mass ratio of 1:0.6:1. The selenium source includes selenomethionine and seleno-L-cysteine in a mass ratio of 1:2.

[0047] The trace elements include iron (ferrous sulfate), zinc (zinc sulfate), boron (borax), and manganese (manganese sulfate) in a mass ratio of 1:0.3:0.5:0.2.

[0048] This example also provides a preparation method of the amino acid selenium foliar fertilizer powder, which includes the following steps:

[0049] At 40 °C, according to the formula, amino acids and selenium source were added with water (the amount of water added was 5 times the mass of amino acids) and mixed evenly, and the pH value was adjusted to 7.0 to obtain Solution 1; at 50 °C, the anionic surfactant was added with water (the amount of water added was 3 times the mass of the anionic surfactant) and mixed evenly, and the pH value was adjusted to 6.3 to obtain Solution 2; while it was still hot, Solution 1 was added dropwise into Solution 2. After dropping, it was stirred at 55 °C and a speed of 60 r / min for 8 min to obtain a mixed solution. The mixed solution was spray-dried (spray pressure 0.6 MPa, feeding speed 0.8 L / h, inlet air temperature 125 °C) to obtain Powder 1. The other raw materials in the foliar fertilizer formula were mixed evenly and freeze-dried (-30 °C, vacuum degree 20 Pa) to obtain Powder 2. Powder 1 and Powder 2 were mixed evenly to obtain the amino acid selenium foliar fertilizer powder. Example 3

[0050] This example provides an amino acid selenium foliar fertilizer, which is different from Example 2 in that the anionic surfactant is sodium laurate. Example 4

[0051] This example provides an amino acid selenium foliar fertilizer, which is different from Example 2 in that the anionic surfactant is sodium oleate. Example 5

[0052] This example provides an amino acid selenium foliar fertilizer, which includes the following raw materials by mass: 30 parts of amino acids, 0.6 part of selenium source, 1 part of trace elements, 0.3 part of urea, 0.05 part of sinigrin, 0.5 part of auxiliaries (polyoxyethylene sorbitan monooleate), and 0.3 part of anionic surfactant (dipotassium tocopherol phosphate).

[0053] The amino acids include lysine, histidine, and arginine with a mass ratio of 1:0.3:0.5. The selenium source includes selenomethionine and seleno-L-cysteine with a mass ratio of 1:0.3.

[0054] The trace elements include iron (ferrous sulfate), zinc (zinc sulfate), boron (borax), and manganese (manganese sulfate) with a mass ratio of 1:0.1:0.1:0.1.

[0055] This example also provides a preparation method of the amino acid selenium foliar fertilizer powder, which includes the following steps:

[0056] At 30 °C, the amino acids and selenium source were mixed evenly with water (the water addition amount was 3 times the mass of the amino acids) according to the formula, and the pH value was adjusted to 6.8 to obtain Solution 1; at 40 °C, the anionic surfactant was mixed evenly with water (the water addition amount was 2 times the mass of the anionic surfactant), and the pH value was adjusted to 6.0 to obtain Solution 2; Solution 1 was added dropwise to Solution 2 while it was still hot. After dropping, it was stirred at 50 °C and a speed of 100 r / min for 5 min to obtain a mixed solution. The mixed solution was spray-dried (spray pressure 0.5 MPa, feeding speed 0.7 L / h, inlet air temperature 120 °C) to obtain Powder 1. The other raw materials in the foliar fertilizer formula were mixed evenly and freeze-dried (-30 °C, vacuum degree 20 Pa) to obtain Powder 2. Powder 1 and Powder 2 were mixed evenly to obtain the amino acid selenium foliar fertilizer powder. Example 6

[0057] This example provides an amino acid selenium foliar fertilizer, which includes the following raw materials according to mass parts: 80 parts of amino acids, 5 parts of selenium source, 6 parts of trace elements, 5 parts of urea, 0.2 part of sinigrin, 3 parts of auxiliary agent (lauryl alcohol polyoxyethylene ether), and 2 parts of anionic surfactant (d-α-tocopheryl phosphate disodium).

[0058] The amino acids include lysine, histidine, and arginine with a mass ratio of 1:1:3. The selenium source is selenomethionine and selenyl-L-cysteine with a mass ratio of 1:5.

[0059] The trace elements include iron (ferrous sulfate), zinc (zinc sulfate), boron (borax), and manganese (manganese sulfate) with a mass ratio of 1:0.6:1:0.5.

[0060] This example also provides a preparation method for the amino acid selenium foliar fertilizer powder, which includes the following steps:

[0061] At 50 °C, the amino acids and selenium source were mixed evenly with water (the water addition amount was 10 times the mass of the amino acids) according to the formula, and the pH value was adjusted to 7.3 to obtain Solution 1; at 70 °C, the anionic surfactant was mixed evenly with water (the water addition amount was 6 times the mass of the anionic surfactant), and the pH value was adjusted to 6.7 to obtain Solution 2; Solution 1 was added dropwise to Solution 2 while it was still hot. After dropping, it was stirred at 60 °C and a speed of 30 r / min for 10 min to obtain a mixed solution. The mixed solution was spray-dried (spray pressure 0.8 MPa, feeding speed 0.9 L / h, inlet air temperature 130 °C) to obtain Powder 1. The other raw materials in the foliar fertilizer formula were mixed evenly and freeze-dried (-30 °C, vacuum degree 20 Pa) to obtain Powder 2. Powder 1 and Powder 2 were mixed evenly to obtain the amino acid selenium foliar fertilizer powder.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that the foliar fertilizer does not contain sinigrin.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 1 is that the sinigrin in the foliar fertilizer is replaced with lauryl glucoside.

[0066] Comparative Example 3

[0067] The difference between this comparative example and Example 1 is that the sinigrin in the foliar fertilizer is replaced with potassium sulfate.

[0068] Comparative Example 4

[0069] The difference between this comparative example and Example 2 is that the amino acid selenium foliar fertilizer does not contain tocopherol sodium phosphate.

[0070] Comparative Example 5

[0071] The difference between this comparative example and Example 2 is that the preparation method of the amino acid selenium foliar fertilizer powder is as follows: take each raw material according to the formula, mix them evenly and then freeze-dry (-30 °C, vacuum degree 20 Pa) to obtain it.

[0072] Comparative Example 6

[0073] The difference between this comparative example and Example 2 is that in the preparation method of the amino acid selenium foliar fertilizer powder, the pH of Solution 2 is not adjusted. At this time, the preparation steps of Solution 2 are as follows:

[0074] At 50 °C, add water to the anionic surfactant and mix evenly to obtain Solution 2.

[0075] Comparative Example 7

[0076] The difference between this comparative example and Example 2 is that in the preparation method of the amino acid selenium foliar fertilizer powder, the pH of Solution 1 is not adjusted. At this time, the preparation steps of Solution 1 are as follows:

[0077] At 40 °C, mix the amino acid and selenium source with water evenly according to the formula to obtain Solution 1.

[0078] Comparative Example 8

[0079] The difference between this comparative example and Example 2 is that in the preparation method of the amino acid selenium foliar fertilizer powder, the preparation steps of Solution 1 and Solution 2 are as follows:

[0080] At 40 °C, mix the amino acid and selenium source with water evenly according to the formula, adjust the pH value to 6.0 to obtain Solution 1; at 50 °C, add water to the anionic surfactant and mix evenly, adjust the pH value to 5.0 to obtain Solution 2.

[0081] Comparative Example 9

[0082] The difference between this comparative example and Example 2 lies in that in the preparation method of the amino acid selenium foliar fertilizer powder, the preparation steps of Solution 1 and Solution 2 are as follows:

[0083] At 40 °C, according to the formula, amino acids and selenium sources are mixed with water evenly, and the pH value is adjusted to 8.0 to obtain Solution 1; at 50 °C, an anionic surfactant is mixed with water evenly, and the pH value is adjusted to 7.5 to obtain Solution 2.

[0084] I. Quality inspection of the foliar fertilizer of the present invention

[0085] Referring to the requirements of NY 1429-2010 "Water-soluble fertilizers containing amino acids", the quality inspection of the amino acid selenium foliar fertilizers prepared in Examples 1-6 of the present invention was carried out, and the results are shown in Table 1 below.

[0086] Table 1

[0087]

[0088] As can be seen from Table 1, the water-insoluble matter and harmful element contents of the amino acid selenium foliar fertilizers prepared in the present invention all meet the requirements of NY1429-2010.

[0089] II. Rice field experiment

[0090] Test method: The rice field is a transplanted early rice field. Before transplanting the rice, a base fertilizer (compound fertilizer, N:P2O5:K2O = 18:9:11, application rate is 50 kg / mu) is applied after land preparation, and the base fertilizer is applied in one-time full-layer basal application. A total of 15 groups of test treatments (applying the amino acid selenium foliar fertilizers prepared in Examples 1-6 and Comparative Examples 1-9 respectively) were set, and an equal amount of clear water was used as the blank control group. The foliar fertilizers were sprayed in the conventional manner during the rice seedling stage and heading stage. The spraying amount of the foliar fertilizer during the seedling stage was: for Example 1 and Comparative Examples 1-3: 70 g / mu, dilution multiple was 300 times; for Examples 2-6 and Comparative Examples 4-9: 31 g / mu, the foliar fertilizer powder was dissolved with 1.2 times the amount of water and then diluted, dilution multiple was 300 times. The spraying amount of the foliar fertilizer during the heading stage was: for Example 1 and Comparative Examples 1-3: 120 g / mu, dilution multiple was 400 times; for Examples 2-6 and Comparative Examples 4-9: 54 g / mu, the powder was dissolved with 1.2 times the amount of water and then diluted, dilution multiple was 400 times. Conventional field management was carried out during the test process.

[0091] After the rice was mature, the rice yield was counted, and the selenium content of brown rice in the rice was measured. The results are shown in Table 2.

[0092] Table 2

[0093]

[0094] As can be seen from Table 2, after the amino acid selenium foliar fertilizer prepared in Examples 1-6 of the present invention was applied to rice cultivation, its yield increasing effect was obvious, increasing from 1240 jin / mu to 1356-1408 jin / mu, and the yield increasing rate was 8.80%-13.58%. The total selenium content in brown rice increased from 28.9 μg / kg to 225.6 μg / kg, and the organic selenium content in brown rice increased from 17.3 μg / kg to 221.1 μg / kg. In particular, Examples 2, 5, and 6 had better yield increasing effects, with the yield increasing rate as high as 13.42-13.58%, the total selenium content in brown rice as high as 215.5-225.6 μg / kg, and the organic selenium content in brown rice as high as 211.2-221.1 μg / kg, showing good fertilizer efficiency.

[0095] III. Influence of the foliar fertilizer spraying of the present invention on leaf stomata

[0096] For the rice plants sprayed with the foliar fertilizer at the heading stage in the above field experiment, after 1 h, intact rice leaves were taken, and temporary mounts were made respectively according to the conventional method, and the stomatal opening conditions of the leaves in different experimental groups were observed under a microscope. The results are shown in Table 3 below.

[0097] Table 3

[0098]

[0099] As can be seen from Table 3, compared with Comparative Examples 1-3 and the blank control group, the amino acid selenium foliar fertilizer prepared in Example 1 of the present invention can effectively improve the stomatal opening conditions of plant leaves, which helps the rice leaves to better absorb nutrients.

[0100] IV. Adhesion of the foliar fertilizer of the present invention on leaves

[0101] Take intact rice leaves in the growth period of the field experiment. Using the five-point sampling method and avoiding the edge of the experimental field, 20 rice leaves were taken for each treatment, with a total of twelve groups of experiments (Examples 1-6 and Comparative Examples 4-9). After the rice leaves in each group were rinsed with deionized water and the surface moisture was blotted dry, the amino acid selenium foliar fertilizers prepared in Examples 1-6 and Comparative Examples 4-9 of the present invention were evenly sprayed on the leaves until the leaves were just moist without liquid droplets flowing down, and the foliar fertilizer spraying amount of each group of leaves was recorded. The rice leaves sprayed with the foliar fertilizer were placed in an incubator at 40 °C (simulating the outdoor temperature in summer) to air dry, and then 20 mL of deionized water was evenly sprayed on the leaves to simulate rainwater. The liquid washed down was collected and digested, and the nitrogen concentration and selenium concentration in the solution were measured. Through this concentration and the foliar fertilizer spraying amount, the nitrogen retention rate and selenium retention rate of each group of foliar fertilizers after spraying on the rice leaves can be calculated, which can reflect the adhesion of the foliar fertilizer of the present invention. The results are shown in Table 4 below.

[0102] Nitrogen or selenium retention rate (%) = 100% × (amount of foliar fertilizer sprayed on a single rice leaf × nitrogen or selenium concentration in the foliar fertilizer formula - amount of simulated rainwater scouring solution × nitrogen or selenium concentration in the rainwater scouring solution) / (amount of foliar fertilizer sprayed on a single rice leaf × nitrogen or selenium concentration in the foliar fertilizer formula).

[0103] Table 4

[0104]

[0105] As can be seen from Table 4, compared with the amino acid selenium foliar fertilizer of Example 1, after the amino acid selenium foliar fertilizers prepared in Examples 2-6 of the present invention were sprayed on rice leaves, the nitrogen and selenium retention rates both increased, ranging from 75.3 - 88.7% and 78.8 - 91.3% respectively. In particular, the foliar fertilizers of Examples 2, 4, and 5 had better adhesiveness, with the nitrogen retention rate as high as 88.3 - 88.7% and the selenium retention rate as high as 90.8 - 91.3%, showing good adhesion performance.

[0106] Compared with Example 2, the preparation processes of the amino acid selenium foliar fertilizers in Comparative Examples 4 - 9 were changed respectively, and as a result, both the nitrogen and selenium retention rates decreased.

[0107] V. Absorption rate of the foliar fertilizer of the present invention on leaves

[0108] 1. Nitrogen absorption rate at different times under the same light conditions

[0109] Taking the nitrogen nutrient element as an example, referring to the above-mentioned adhesiveness measurement method, before spraying the foliar fertilizer at the heading stage, select the rice in the field experiment. Using the five-point sampling method, avoiding the edges of the experimental field, select 20 individual rice plants for each treatment group, with a total of eight groups of experiments (Examples 1, 2 and Comparative Examples 4 - 9). After each group of rice plants is rinsed with deionized water and the water on the leaf surface is blotted dry, then evenly spray the amino acid selenium foliar fertilizers prepared in Examples 1, 2 and Comparative Examples 4 - 9 of the present invention on the rice leaves (the light conditions are kept consistent, that is, 16:00 in the afternoon of the same day), spray until the leaves are just moist without droplets flowing down, and record the amount of foliar fertilizer sprayed on each group of rice plants. After spraying, take the rice leaves of each group at different times and put them into ultrasonic cleaning, measure the nitrogen concentration in the cleaning solution, and through this concentration and the amount of foliar fertilizer sprayed, the nitrogen absorption rate on the rice leaves at different times after spraying the foliar fertilizer can be calculated. The results are shown in Table 5.

[0110] Nitrogen absorption rate (%) = 100% × (amount of foliar fertilizer sprayed on the leaves of a single rice plant × nitrogen concentration in the foliar fertilizer formula - amount of ultrasonic cleaning solution × nitrogen concentration in the ultrasonic cleaning solution) / (amount of foliar fertilizer sprayed on the leaves of a single rice plant × nitrogen concentration in the foliar fertilizer formula).

[0111] Table 5

[0112]

[0113] As can be seen from Table 5, compared with the amino acid selenium foliar fertilizer of Example 1, the amino acid selenium foliar fertilizer prepared in Example 2 of the present invention can reach a nitrogen absorption rate of 95% 5 hours after spraying on rice leaves, and the nitrogen absorption rate can reach 98% 12 hours after spraying, showing a relatively fast absorption rate of the foliar fertilizer.

[0114] Compared with Example 2, the preparation process of the amino acid selenium foliar fertilizer was changed in Comparative Examples 4-9, and as a result, the nitrogen absorption rate at different times decreased.

[0115] 2. Nitrogen absorption rate at the same time under different light conditions

[0116] Before spraying the foliar fertilizer at the heading stage, select the rice in the field experiment. Using the five-point sampling method, avoid the edge of the experimental field. Select 20 individual rice plants for each treatment, a total of five groups of experiments (Examples 1-4 and Comparative Example 4). After each group is rinsed with deionized water and the water on the leaf surface is blotted dry, then under different light conditions (10:00 am, 12:00 noon, 14:00 pm, and 17:00 pm on a sunny day), evenly spray the amino acid selenium foliar fertilizers prepared in Examples 1-4 and Comparative Example 4 of the present invention on the rice leaves until the leaves are just moist without droplets flowing down, and record the spraying amount of the foliar fertilizer for each group of rice. After spraying for 5 hours, take the rice leaves of each group and put them into an ultrasonic cleaner to measure the nitrogen concentration in the cleaning solution. Through this concentration and the spraying amount of the foliar fertilizer, the nitrogen absorption rate on the rice leaves after spraying the foliar fertilizer under different lights can be calculated. The results are shown in Table 6.

[0117] Table 6

[0118]

[0119] As can be seen from Table 6, compared with the amino acid selenium foliar fertilizer of Example 1, under different light conditions, the nitrogen absorption rate is relatively stable and the change range is not large after spraying the amino acid selenium foliar fertilizer prepared in Example 2 of the present invention on the rice leaves, indicating that the foliar fertilizer of Example 2 has a wide adaptability range to light conditions.

[0120] Compared with Example 2, the foliar fertilizer of Comparative Example 4 does not contain tocopherol sodium phosphate, and the change range of the nitrogen absorption rate under different light conditions becomes larger.

[0121] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An amino acid selenium foliar fertilizer, characterized in that: Comprising the following raw materials according to parts by mass: 30 - 80 parts of amino acids, 0.6 - 5 parts of selenium source, 0.05 - 0.2 parts of sinigrin.

2. The amino acid selenium foliar fertilizer according to claim 1, characterized in that: The amino acids include any one or several of aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine and arginine; the selenium source includes any one or two of selenomethionine and seleno-L-cysteine.

3. The amino acid selenium foliar fertilizer according to claim 1, characterized in that: The amino acid selenium foliar fertilizer further includes any one or several of 0.5 - 3 parts of auxiliary agent, 1 - 6 parts of trace elements, 0.1 - 5 parts of nitrogen fertilizer and 50 - 100 parts of water.

4. The amino acid selenium foliar fertilizer according to claim 1, wherein: The amino acid selenium foliar fertilizer further includes 0.3 - 2 parts of anionic surfactant, and the anionic surfactant is disodium tocopheryl phosphate, sodium laurate, sodium oleate or sodium stearate.

5. The amino acid selenium foliar fertilizer according to claim 2, characterized in that: The amino acids include any one or several of lysine, histidine and arginine; the selenium source includes selenomethionine and seleno-L-cysteine with a mass ratio of 1:(0.3 - 5).

6. The amino acid selenium foliar fertilizer according to claim 4, wherein: The anionic surfactant is disodium tocopheryl phosphate.

7. A preparation method of the amino acid selenium foliar fertilizer according to claim 3, characterized in that: The amino acid selenium foliar fertilizer is in the form of aqueous solution or powder. The preparation method of the aqueous solution includes the following steps: weigh water according to the formula, then add other raw materials in the formula in sequence, and stir evenly to obtain; The preparation method of the powder includes: take each raw material according to the formula, mix evenly and then freeze-dry to obtain.

8. A preparation method of the amino acid selenium foliar fertilizer according to any one of claims 4 or 6, characterized in that: The amino acid selenium foliar fertilizer is in the form of powder, and its preparation method includes the following steps: Mix amino acids and selenium source with water evenly according to the formula, adjust the pH value to 6.8 - 7.3 to obtain solution 1; mix the anionic surfactant with water evenly, adjust the pH value to 6.0 - 6.7 to obtain solution 2; dropwise add solution 1 into solution 2, and after dropping, obtain a mixed solution; spray-dry the mixed solution to obtain powder 1; mix other raw materials in the foliar fertilizer formula evenly and freeze-dry to obtain powder 2; mix powder 1 and powder 2 evenly to obtain.

9. The preparation method according to claim 8, characterized in that: The water addition amount for preparing solution 1 is 3 - 10 times the mass of amino acids, and the water addition amount for preparing solution 2 is 1 - 6 times the mass of the anionic surfactant.

10. Application of the amino acid selenium foliar fertilizer according to claim 1 in the planting of food crops or fruits and vegetables.

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