阅读说明：本技术 一种用于植物外源硒叶面肥料及其制备和使用方法 (Foliar fertilizer for exogenous selenium of plants and preparation and use methods thereof ) 是由 刘嘉琛 刘让斌 于 2021-07-07 设计创作，主要内容包括：本发明提出了一种用于植物外源硒叶面肥料及其制备和使用方法,涉及植物肥料领域。硒肥料包括：亚硒酸钠溶液220～250份、芸苔素内酯1.5～4份、硫酸铵55～60份、硫酸钾100～120份、氨基酸营养液10～30份、微量元素硼20～30份、微量元素锌15～30份和水10000～12000份。制备方法为：往亚硒酸钠中先加水进行溶解,然后加水稀释,配制成硒元素水溶液；然后加入微量元素硼、微量元素锌、芸苔素内酯、硫酸铵、硫酸钾和氨基酸营养素,配制成预处理水溶液。本发明产品可以促进植物光合吸收,达到富硒和增产等效果。(The invention provides an exogenous selenium foliar fertilizer for plants and a preparation method and a use method thereof, and relates to the field of plant fertilizers. The selenium fertilizer comprises: 220-250 parts of sodium selenite solution, 1.5-4 parts of brassinolide, 55-60 parts of ammonium sulfate, 100-120 parts of potassium sulfate, 10-30 parts of amino acid nutrient solution, 20-30 parts of trace element boron, 15-30 parts of trace element zinc and 10000-12000 parts of water. The preparation method comprises the following steps: adding water into sodium selenite for dissolving, and then adding water for diluting to prepare a selenium element aqueous solution; then adding trace element boron, trace element zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient to prepare a pretreatment aqueous solution. The product of the invention can promote the photosynthetic absorption of plants, and achieve the effects of selenium enrichment, yield increase and the like.)

1. The exogenous plant selenium fertilizer is characterized by comprising the following raw materials in parts by weight: 220-250 parts of sodium selenite, 1.5-4 parts of brassinolide, 55-60 parts of ammonium sulfate, 100-120 parts of potassium sulfate, 10-30 parts of amino acid nutrient solution, 20-30 parts of trace element boron, 15-30 parts of trace element zinc and 10000-12000 parts of water.

2. The exogenous selenium fertilizer for plants as claimed in claim 1, wherein said sodium selenite has a purity of 92-98%.

3. The exogenous selenium fertilizer for plants of claim 1, wherein said amino acid nutrient solution consists of active amino acids, cytokinins, polysaccharides and small peptides.

4. The preparation method of the plant exogenous selenium fertilizer according to any one of claims 1 to 3, characterized by comprising the following steps:

dissolving sodium selenite, and then adding water for dilution to prepare a selenium element aqueous solution;

then adding trace elements of boron, zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient into the selenium element water solution to prepare a pretreatment water solution;

and (4) sterilizing the pretreated aqueous solution to obtain the exogenous selenium fertilizer.

5. The preparation method of the plant exogenous selenium fertilizer as claimed in claim 4, wherein the dissolving is carried out with hot water for 5-7 min.

6. The method for preparing the exogenous selenium fertilizer for plants according to claim 5, wherein the temperature of the hot water is 81-84 ℃.

7. The preparation method of the plant exogenous selenium fertilizer as claimed in claim 4, wherein the sterilization is carried out at 70-80 ℃ for 30-40 min.

8. The use method of the plant exogenous selenium fertilizer according to any one of claims 1 to 3, wherein the exogenous selenium fertilizer is diluted by adding water and then sprayed or irrigated to the leaves of the plant.

9. The use method of the plant exogenous selenium fertilizer according to claim 8, wherein the dilution with water is specifically such that the ratio of the exogenous selenium fertilizer to water is 1 mL: (400-600) g.

10. The use method of the plant exogenous selenium fertilizer according to claim 8, wherein the number of foliar sprays is at least 5, and the time interval between each two sprays is 7 days or more.

Technical Field

The invention relates to the field of plant fertilizers, in particular to a plant exogenous selenium fertilizer and a preparation method and a use method thereof.

Background

Selenium distribution in China is extremely uneven, and some areas are areas rich in selenium and some areas are areas deficient in selenium. Selenium is an indispensable trace element in human bodies, has important functions for preventing tumors, liver diseases and the like and maintaining normal functions of important organs such as heart, liver, lung, stomach and the like, and is easy to cause diseases such as keshan disease, cardiovascular and cerebrovascular diseases, hypertension and the like due to long-term selenium deficiency of human bodies, so that the selenium deficiency condition needs to be improved by taking a proper amount of selenium-enriched food.

The plant food is a common selenium carrier, and can be used as selenium-rich food. The organic water-soluble fertilizer is a mixed fertilizer which is completely soluble in water and has multiple components, fully combines the advantages of organic fertilizers and water-soluble fertilizers, and can meet the requirement of organic and water-fertilizer integration of modern agriculture. Selenium enrichment of plants by selenium-enriched organic water-soluble fertilizers has been proven to be a safe, low-cost, efficient and convenient selenium enrichment means. The selenium content of plants can be improved by spraying the selenium-rich organic fertilizer on roots and leaves in low-selenium areas so as to meet the physiological requirements of human and animals.

However, the existing selenium-rich fertilizer really acts on plants, and can effectively improve the selenium content of the plants.

Disclosure of Invention

The invention aims to provide a plant exogenous selenium fertilizer which can ensure that agricultural products can achieve the effects of enriching selenium and increasing yield at the same time.

The invention also aims to provide a preparation method of the plant exogenous selenium fertilizer, which is simple and convenient.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

On one hand, the embodiment of the application provides a plant exogenous selenium fertilizer, which comprises the following raw materials in parts by weight: 220-250 parts of sodium selenite, 1.5-4 parts of brassinolide, 55-60 parts of ammonium sulfate, 100-120 parts of potassium sulfate, 10-30 parts of amino acid nutrient solution, 20-30 parts of trace element boron, 15-30 parts of trace element zinc and 10000-12000 parts of water.

On the other hand, the embodiment of the application provides a preparation method of the plant exogenous selenium fertilizer, which comprises the following steps:

dissolving sodium selenite, and then adding water for dilution to prepare a selenium element aqueous solution;

adding trace elements of boron, zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrients into a selenium aqueous solution to prepare a pretreatment aqueous solution;

and (4) sterilizing the pretreated aqueous solution to obtain the exogenous selenium fertilizer.

In another aspect, the embodiment of the present application further provides a method for using a plant exogenous selenium fertilizer, which includes the following steps: after the exogenous selenium fertilizer is diluted by adding water, the foliage of the plants is sprayed or irrigated.

Compared with the prior art, the embodiment of the invention has at least the following advantages or beneficial effects:

the exogenous selenium fertilizer adopts sodium selenite, brassinolide, ammonium sulfate, potassium sulfate, amino acid nutrient solution and trace elements as raw materials, can promote plant photosynthetic absorption, thereby promoting fruit growth, increases the crop yield by 5-20% on a par, is rich in selenium element in mature products, has the advantage of rich nutrition, and can prolong the storage period of fruits. The invention researches the optimum selenium concentration content in the plant exogenous selenium fertilizer through a plurality of years of tests, and can ensure that agricultural products can achieve the effects of enriching selenium and increasing yield.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to specific examples.

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 220-250 parts of sodium selenite, 1.5-4 parts of brassinolide, 55-60 parts of ammonium sulfate, 100-120 parts of potassium sulfate, 10-30 parts of amino acid nutrient solution, 20-30 parts of trace element boron, 15-30 parts of trace element zinc and 10000-12000 parts of water.

Sodium selenite has the following effects on plants: 1. the selenium is a component of glutathione peroxidase, participates in reduction reaction of all peroxides, and can prevent cell membranes and tissues from being damaged by the peroxides; 2. the selenium element is fully combined with the protein and active organic ingredients of the plants to form the exogenous selenium leaf surfaces of the plants, namely the plant selenoprotein which is an important nutrient for the plants after entering the bodies of the plants; 3. the structure and the function of sperm cells are maintained, and selenium deficiency can cause poor development of testicle seminiferous tubules and reduction of sperms; 4. the synthesis of coenzyme Q is involved, and the coenzyme Q plays a role in hydrogen transfer in the respiratory chain; 5. the toxicity of heavy metals such as mercury, lead, cadmium, silver, thallium and the like is reduced, selenium can form insoluble selenide with the metals, and the toxic effect of the heavy metals on organisms is obviously reduced; 6. the selenium has certain toxicity, acute poisoning can occur when sodium selenite is taken or injected by human and livestock or sprayed or irrigated to plants in an excessive dose, animals show dyskinesia, body temperature rise, rapid and weak pulse, dyspnea and cyanosis, serious people die due to respiratory failure, plants show black brown spots on leaf surfaces or stems, and the plants can inhibit the growth of crops or cause withering, water loss and death when the plants are seriously withered and die.

The brassinolide has the unidirectional pertinence different from other plant growth regulators in the aspects of promoting the yield increase of crops and improving the quality, not only has the physiological functions of auxin and cytokinin, but also has the functions of improving photosynthesis, regulating nutrient distribution, promoting the transportation of stem leaf carbohydrates to granules, improving the stress resistance of the crops to external adverse factors, promoting the growth capacity of weak parts of the plants and the like.

The ammonium sulfate can make branches and leaves grow vigorously, improve the quality and yield of fruits, enhance the resistance of crops to disasters, and can be used as a base fertilizer, an additional fertilizer and a seed fertilizer.

The potassium sulfate has the following effects: potassium sulfate is a compound generated by combining sulfate ions and potassium ions, and the solid of the potassium sulfate is colorless or white hexagonal or orthorhombic crystal or granular powder. Soluble in water, insoluble in alcohol, acetone and carbon disulphide, it has a bitter salty taste. Potassium sulfate is a common potash fertilizer in agriculture, and has a potassium content of about 50%.

Amino acids are a generic term for a class of organic compounds containing both amino and carboxyl groups. The basic constituent unit of biological functional macromolecular protein is the basic substance of protein required by animal and plant nutrition. The main functions are as follows: improving the disease resistance of crops, improving the immunity of crops and improving the stress resistance of crops.

Function of trace element boron: boron is a trace element necessary for vegetable growth, and is also critical at some stage of plant growth, and can cause abnormal growth if supplied insufficiently. 1. Boron can promote the transportation and metabolism of carbohydrates produced by photosynthesis, and boron deficiency can influence the transportation of carbohydrates and the absorption and utilization of nutrients by various organs of crops. 2. Boron participates in the formation of cell walls, and the synthesis of hemicellulose is blocked in the absence of boron, so that the cell walls cannot be normally formed, and the condition of stem and vine transverse cracking of some crops is caused. When the boron is deficient, the crops can generate the symptoms of cork formation near the growing point, and the stems of some plants are cracked, so that the conditions of 'broken ends', 'broken ends' and the like are generated. 3. Boron promotes cell division and elongation. The growth of the root tip and the lateral root of the crop can be inhibited by the lack of boron, and the growth is stopped. The density of the main root and the lateral root is reduced due to boron deficiency, and the absorption capacity of crops is influenced. 4. Sufficient boron can inhibit the excessive formation of indoleacetic acid, thereby ensuring the normal growth of the growing point of the plant. Otherwise, the growing point of the crop is inhibited, the growing point is dead when the growing point is serious, and axillary buds germinate after the terminal buds die, so that the phenomenon of lateral branch clustering occurs. 5. Boron promotes flower bud differentiation and pollen and ovary development, and the phenomenon of 'flower but not fruit' and flower and fruit drop of crops is caused by boron deficiency. It also causes the emergence of blight disease on tomatoes, accompanied by longitudinal depressions in the stem. Therefore, before flowering of various vegetables or in a continuous flowering stage, the leaves should be supplemented with boron for 2-3 times.

The function of the trace element zinc: the synthesis of auxin is indirectly influenced in the crop body, when the crop is in zinc deficiency, the content of the auxin in stems and buds is reduced, the growth is in a stagnation state, and the plant is short; meanwhile, zinc is also an activator of a plurality of enzymes, and contributes to photosynthesis by widely influencing the carbon and nitrogen metabolism of plants; meanwhile, the zinc can also enhance the stress resistance of plants; increase the weight of the seeds and change the ratio of the seeds to the stems. For example: 1. zinc is a constituent element of some dehydrogenases, carbonic anhydrases and phospholipases, which play an important role in substance hydrolysis, redox processes and protein synthesis in plants; 2. zinc participates in the synthesis of auxin indoleacetic acid; 3. zinc is an essential component for stabilizing cell ribosomes; 4. zinc participates in chlorophyll formation.

In some embodiments of the invention, the purity of the sodium selenite is 92-98%, and the content of selenium can be increased, so that the proportion of selenium in the whole exogenous selenium fertilizer is increased.

In some embodiments of the present invention, the amino acid nutrient solution is composed of active amino acids, cytokinins, polysaccharides, and small peptides, the active amino acids refer to 17 kinds of amino acids having active factors, including alanine: the synthesized chlorophyll is increased, the open pores are adjusted, and the resistance to pathogenic bacteria is realized; arginine: the growth of root systems is enhanced, and the plant growth promoter is a precursor for synthesizing plant endogenous hormone polyamine and improves the salt stress resistance of crops; aspartic acid: enhancing seed germination, protein synthesis, and nitrogen supply during stressed periods of growth; cysteine: sulfur containing amino acids to maintain cell function and as an antioxidant; glutamic acid: stimulating the growth of plants and improving the resistance to adverse climatic conditions; glycine: the fertilizer has unique effect on photosynthesis of crops, is beneficial to the growth of the crops, increases the content of sugar in the crops and is a natural metal chelating agent; histidine: regulate stomatal opening and provide a precursor to carbon skeleton hormones, catalytic enzymes for cytokinin synthesis; isoleucine and leucine: improve salt stress resistance, pollen activity and germination, and aromatic precursor; lysine: enhancing chlorophyll synthesis and increasing drought tolerance; methionine: precursors for the synthesis of the plant endogenous hormones ethylene and polyamines; phenylalanine: precursor substances for promoting the synthesis of lignin and anthocyanin; proline: the tolerance of the plant to osmotic stress is increased, and the stress resistance and the pollen activity of the plant are improved; serine: participating in cell tissue differentiation and promoting germination; threonine: the tolerance and the insect damage are improved, and the humification process is improved; tryptophan: the precursor of the synthesis of the endogenous hormone auxin indole acetic acid improves the synthesis of aromatic compounds; tyrosine: the drought tolerance is increased, and the pollen germination is improved; valine: the germination rate of the seeds is improved, and the flavor of the crops is improved.

A preparation method of a plant exogenous selenium fertilizer comprises the following steps:

dissolving sodium selenite, and then adding water for dilution to prepare a selenium element aqueous solution;

adding trace elements of boron, zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrients into a selenium aqueous solution to prepare a pretreatment aqueous solution;

and (4) sterilizing the pretreated aqueous solution to obtain the exogenous selenium fertilizer.

In some embodiments of the invention, the dissolution is carried out in hot water for 5-7 min, and the hot water can accelerate the dissolution of sodium selenite; compared with the selenium dissolved at normal temperature, the selenium dissolved in the hot water is higher in selenium content in the selenium water solution.

In some embodiments of the present invention, the temperature of the hot water is 81-84 ℃.

In some embodiments of the present invention, the sterilization is performed at 70-80 ℃ for 30-40 min.

A method for using the exogenous selenium fertilizer for plant features that the exogenous selenium fertilizer is diluted by adding water and sprayed to the leaves of plant or irrigated.

In some embodiments of the present invention, the above dilution with water is specifically a ratio of the exogenous selenium fertilizer to water of 1 mL: (400-600) g. Wherein the exogenous selenium fertilizer adopted in the seedling stage is prepared according to the proportion of 1: 600 is mixed with water for use, namely 60kg of water is mixed with 100ml of exogenous selenium fertilizer, and the mixture is used after flower bud differentiation or in the jointing stage and the booting stage of crops according to the proportion of 1: 400 is mixed with water for use, namely, 40kg of water is mixed with each 100ml of exogenous selenium fertilizer.

In some embodiments of the present invention, the number of the foliar sprays is at least 5, the time interval between every two foliar sprays is more than 7 days, the foliar sprays and the back of the plant are preferably watered when the foliar sprays meet the raining requirement within 4 hours of the foliar sprays, and the foliar sprays and the back of the plant are preferably watered before 10 am or after 4 pm.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 250g of 95% purity sodium selenite, 3g of brassinolide, 60g of ammonium sulfate, 110g of potassium sulfate, 20g of amino acid nutrient solution, 25g of trace element boron, 20g of trace element zinc and 10000g of water.

In this example, the amino acid nutrient solution is prepared from active amino acids, cytokinins, polysaccharides and small peptides in a mass ratio of 50: 30: 15: 5.

A preparation method of a plant exogenous selenium fertilizer comprises the following steps:

firstly adding a small amount of hot water with the temperature of 83.2 ℃ into sodium selenite, stirring for 7min for complete dissolution, and then adding 10000g of distilled water for dilution to prepare a selenium element aqueous solution;

after the selenium element water solution is cooled to room temperature, adding trace element boron, trace element zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient to prepare a pretreatment water solution;

and (3) carrying out disinfection and sterilization on the pre-treated water solution in water bath at the temperature of 75 ℃ for 30min to obtain the exogenous selenium fertilizer.

The use method of the plant exogenous selenium fertilizer comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. Carrying out 1: the 400 is diluted by adding water, the foliage and the back of the plant are preferably dripped when the plant is sprayed, the spraying time is 4 pm, the plant is sprayed for 5 times totally, the interval between every two spraying is 7-10 days, and the plant is sprayed for 4 hours and is timely re-sprayed when raining.

Example 2

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 220g of 96% purity sodium selenite, 1.5g of brassinolide, 55g of ammonium sulfate, 120g of potassium sulfate, 30g of amino acid nutrient solution, 30g of trace element boron, 25g of trace element zinc and 11000g of water.

In this example, the amino acid nutrient solution is prepared from active amino acids, cytokinins, polysaccharides and small peptides in a mass ratio of 60: 20: 8: 12.

A preparation method of a plant exogenous selenium fertilizer comprises the following steps:

firstly, adding a small amount of hot water with the temperature of 82.7 ℃ into sodium selenite, stirring for 5min to completely dissolve, and then adding 11000g of distilled water to dilute to prepare a selenium element aqueous solution;

after the selenium element water solution is cooled to room temperature, adding trace element boron, trace element zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient to prepare a pretreatment water solution;

and (3) carrying out sterilization on the pre-treated water solution in a water bath at the temperature of 70 ℃ for 35min to obtain the plant exogenous selenium fertilizer.

A use method of a plant exogenous selenium fertilizer comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. Carrying out 1: the water is added for dilution 600, the plants are sprayed with water on the leaf surfaces and the back surfaces of the plants, the spraying time is 4 pm, the plants are sprayed for 6 times, the interval between every two spraying is 8-10 days, and the plants are sprayed for 4 hours and are timely supplemented with water when raining.

Example 3

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 240g of 98% purity sodium selenite, 2g of brassinolide, 60g of ammonium sulfate, 110g of potassium sulfate, 20g of amino acid nutrient solution, 25g of trace element boron, 15g of trace element zinc and 10000g of water.

In this example, the amino acid nutrient solution is prepared from active amino acids, cytokinins, polysaccharides and small peptides according to a mass ratio of 65: 12: 8: 15.

A preparation method of a plant exogenous selenium fertilizer comprises the following steps:

adding 84 deg.C small amount of hot water into sodium selenite, stirring for 5min for dissolving completely, and adding 10000g of distilled water for dilution to obtain selenium element water solution;

after the selenium element water solution is cooled to room temperature, adding trace element boron, trace element zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient to prepare a pretreatment water solution;

and (3) carrying out sterilization on the pre-treated water solution in water bath for 40min at the temperature of 80 ℃ to obtain the plant exogenous selenium fertilizer.

A use method of a plant exogenous selenium fertilizer comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. Carrying out 1: the 400 is diluted by adding water, the foliage and the back of the plant are preferably dripped when the plant is sprayed, the spraying time is 10 am, the spraying is carried out for 7 times totally, the interval between every two times of spraying is 10-12 days, and the plant is sprayed within 4 hours and is timely re-sprayed when raining.

Example 4

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 250g of sodium selenite with the purity of 98%, 4g of brassinolide, 60g of ammonium sulfate, 120g of potassium sulfate, 30g of amino acid nutrient solution, 30g of trace element boron, 30g of trace element zinc and 12000g of water.

In this example, the amino acid nutrient solution is prepared from active amino acids, cytokinins, polysaccharides and small peptides in a mass ratio of 55: 12: 18: 15.

A preparation method of a plant exogenous selenium fertilizer comprises the following steps:

adding a small amount of hot water with the temperature of 81 ℃ into sodium selenite, stirring for 7min to completely dissolve, and then adding 12000g of distilled water to dilute to prepare a selenium element aqueous solution;

after the selenium element water solution is cooled to room temperature, adding trace element boron, trace element zinc, brassinolide, ammonium sulfate, potassium sulfate and amino acid nutrient to prepare a pretreatment water solution;

and (3) carrying out sterilization on the pre-treated water solution in a water bath at the temperature of 80 ℃ for 35min to obtain the plant exogenous selenium fertilizer.

A use method of a plant exogenous selenium fertilizer comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. Carrying out 1: the 400 is diluted by adding water, the foliage and the back of the plant are preferably dripped when the plant is sprayed, the spraying time is 4 pm, the plant is sprayed for 7 times totally, the interval between every two spraying is 10-12 days, and the plant is sprayed for 4 hours and is timely re-sprayed when raining.

Comparative example 1

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 150g of 95% purity sodium selenite, 3g of brassinolide, 60g of ammonium sulfate, 110g of potassium sulfate, 20g of amino acid nutrient solution, 25g of trace element boron, 20g of trace element zinc and 10000g of water. Wherein the amino acid nutrient solution is prepared from active amino acid, cytokinin, polysaccharide and small peptide according to the mass ratio of 50: 20: 10: 15: 5.

The preparation method and the using method are the same as the example 1.

Comparative example 2

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 300g of 95% purity sodium selenite, 3g of brassinolide, 60g of ammonium sulfate, 110g of potassium sulfate, 20g of amino acid nutrient solution, 25g of trace element boron, 20g of trace element zinc and 10000g of water. Wherein the amino acid nutrient solution is prepared from active amino acid, cytokinin, polysaccharide and small peptide according to the mass ratio of 50: 20: 10: 15: 5.

The preparation method and the using method are the same as the example 1.

Comparative example 3

The exogenous plant selenium fertilizer comprises the following raw materials in parts by weight: 250g of 95% purity sodium selenite, 3g of brassinolide, 60g of ammonium sulfate, 110g of potassium sulfate, 25g of trace element boron, 20g of trace element zinc and 10000g of water.

The preparation method and the using method are the same as the example 1.

Examples of the experiments

The plant exogenous selenium fertilizer prepared in the embodiment 1 of the invention is widely applied to plants such as strawberries, celery, rice, flue-cured tobacco and the like, and the using method comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. In the seedling stage, the ratio of 1: 600, diluting with water, spraying, and performing treatment according to the ratio of 1: 400, diluting with water and spraying; when the plant water-saving agent is sprayed, the foliage and the back of the plant are preferably dripped, the spraying time is 4 pm, the spraying is carried out for 5 times totally, the interval between every two times of spraying is 10-12 days, and the spraying is supplemented in time when raining within 4 hours.

After the crops are mature, the products are sent to a detection mechanism to detect the selenium content, and the detection results are shown in table 1.

TABLE 1

Test product	Detecting items	Detection result and unit	Detection method
				Strawberry (beauty)	Selenium	0.0681mg/kg	GB5009.93-2017 (third method)
Celery	Selenium	0.01mg/kg	GB5009.93-2017 (third method)

As can be seen from the table 1, the selenium content of the product sprayed with the plant exogenous selenium fertilizer can reach the standard GB5009.93-2017 'determination of selenium in food safety national standard food' after the product is mature.

Secondly, the plant exogenous selenium fertilizer prepared in the embodiment 1 of the invention is widely applied to plants such as strawberries, celery, tomatoes and the like, and the using method comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. In the seedling stage, the ratio of 1: 600, diluting with water, spraying, and performing treatment according to the ratio of 1: 400, diluting with water and spraying; when the plant water-saving agent is sprayed, the foliage and the back of the plant are preferably dripped, the spraying time is 4 pm, the spraying is carried out for 5 times totally, the interval between every two times of spraying is 8-12 days, and the spraying is supplemented in 4 hours when raining.

Each plant is provided with a control group, the control group is not sprayed with the plant exogenous selenium fertilizer, and the other conditions are the same; the final yields are shown in table 2.

TABLE 2

As can be seen from Table 2, the yield of the applied exogenous selenium fertilizer for plants is obviously increased compared with that of the control group without the exogenous selenium fertilizer, so that the product of the invention can not only improve the selenium content in crops, but also play a role in increasing the yield.

Secondly, the plant exogenous selenium fertilizer prepared in the embodiment 1 of the invention is widely applied to plants such as strawberry (red pigment), celery, tomato and the like, and the using method comprises the following steps: spraying the exogenous selenium fertilizer to the foliage of plant. In the seedling stage, the ratio of 1: 600, diluting with water, spraying, and performing treatment according to the ratio of 1: 400, diluting with water and spraying; when the plant water-saving agent is sprayed, the foliage and the back of the plant are preferably dripped, the spraying time is 4 pm, the spraying is carried out for 5 times totally, the interval between every two times of spraying is 8-12 days, and the spraying is supplemented in 4 hours when raining.

Each plant is provided with a control group, the control group is not sprayed with the plant exogenous selenium fertilizer, and the other conditions are the same; the fruits are stored after being matured, the storage conditions are the same, and the rotten conditions of the fruits are shown in table 3.

TABLE 3

Crops	Experiment ground	Storage conditions of the test groups	Control group storage conditions
				Strawberry (beauty)	Hunan Yiyang city	Good quality in 6 days	3 days mildewing and rotten
Celery	Anhui Anhuo city	Good quality in 7 days	Wilting in 4 days
				Tomato fruit	West city of Qingdao vegetable	Good quality for 15 days	Rot in 10 days

As can be seen from Table 3, the storage period of the applied exogenous selenium fertilizer for plants is obviously increased compared with that of the control group without the applied exogenous selenium fertilizer, so that the product of the invention can achieve the effect of prolonging the preservation period of crops.

(IV) the plant exogenous selenium fertilizers prepared in examples 1-4 and comparative examples 1-3 are used for planting strawberries, wherein the examples 1-4 are the preferable selenium content in the invention, the comparative example 1 is a low-concentration selenium fertilizer, the comparative example 2 is a high-concentration selenium fertilizer, the comparative example 3 is not added with an amino acid nutrient solution, the using method is the same as that of the example 1, and meanwhile, a blank group is arranged and no plant exogenous selenium fertilizer is applied. When the strawberries in the 8 test groups were ripe, the yields were counted, and the selenium content of the strawberries was measured, and the results are shown in table 4.

TABLE 4

Experimental group	Yield (kg/mu)	Selenium content (mg/kg)
			Example 1	2168.85	0.0681
Example 2	2155.62	0.0677
			Example 3	2158.59	0.0658
Example 4	2139.21	0.0672
			Comparative example 1	2121.85	0.0633
Comparative example 2	2110.25	0.0685
			Comparative example 3	2108.6	0.0680
Blank group	2065.56	Less than 0.01

As can be seen from table 4, the strawberries using the plant exogenous selenium fertilizers in examples 1 to 4 have stable yield and selenium content higher than those of the blank group, and as can be seen from comparative examples 1 and 2, the yield of strawberries is adversely affected by excessive or excessive selenium content in the plant exogenous selenium fertilizers, especially, the yield reduction of strawberries is obvious due to the addition of the high-concentration selenium fertilizer; as can be seen from comparative example 3, the lack of the use of the amino acid nutrient solution had a large effect on the yield of strawberries.

The exogenous selenium fertilizer adopts sodium selenite, brassinolide, ammonium sulfate, potassium sulfate, amino acid nutrient solution and trace elements as raw materials, can promote plant photosynthetic absorption, thereby promoting fruit growth, increases the crop yield by 5-20% on a year-on-year basis, has the advantage of nutrition because the mature product is rich in selenium, and can prolong the storage period of fruits. The invention researches the optimum selenium concentration content in the plant exogenous selenium fertilizer through a plurality of years of tests, and can ensure that agricultural products can achieve the effects of enriching selenium and increasing yield.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.