Foliar fertilizer capable of increasing mineral content of fruits and preparation method of foliar fertilizer

Abstract

The invention provides a foliar fertilizer capable of increasing the mineral content of fruits and a preparation method of the foliar fertilizer. The foliar fertilizer for increasing the mineral content of the fruits is prepared from 1-20 parts by mass of reducing sugar, 1-20 parts by mass of amino acid, 20-80 parts by mass of water and 1-10 parts by mass of metal oxide or metal hydroxide through a Maillard reaction. The foliar fertilizer prepared by the invention has relatively high stability, does not precipitate out in a strong alkaline environment, can be made into a fruit tree foliar fertilizer, and improves the mineral nutrient content of fruits.

Description

Technical Field

[0001] The invention belongs to the field of agriculture and relates to a foliar fertilizer for improving the mineral content of fruits and a preparation method thereof. Background Art

[0002] Soil salinization causes soluble metals to form precipitation, which is difficult for plants to absorb and utilize, resulting in nutritional deficiencies and affecting development and growth. The use of metal complexes for element supplementation can alleviate the deficiency caused by the soil environment. It is generally believed that metals in the form of organic acid chelates can be better absorbed and utilized by plants than metal salts. Chelates of amino acids and other organic acids can be produced by the reaction of organic acids with metal oxides, hydroxides or salts. They are usually made by reacting metal ions with one or more amino acids, dipeptides, polypeptides or protein hydrolyzed ligands under appropriate conditions to form amino acid chelates. Although this type of metal chelate has a certain role in supplementing plant metals, it lacks sufficient stability in the face of an alkaline environment and is easily hydrolyzed or oxidized to form precipitation, making it difficult to apply on a large scale. Summary of the invention

[0003] In order to solve the above problems, the purpose of the present invention is to provide a foliar fertilizer for increasing the mineral content of fruits. The foliar fertilizer can exist stably in an alkaline environment and can effectively increase the mineral content in fruits after application.

[0004] Another object of the present invention is to provide a method for preparing the above-mentioned foliar fertilizer for increasing the mineral content of fruits. The preparation method is based on the Maillard reaction system, and different metal oxides or metal hydroxides are added to obtain a complex solution through a one-pot reaction.

[0005] In order to achieve the above object, the present invention provides a foliar fertilizer for increasing the mineral content of fruit, which is prepared by Maillard reaction of 1-20 parts by mass of reducing sugar, 1-20 parts by mass of amino acid, 20-80 parts by mass of water and 1-10 parts by mass of metal oxide or metal hydroxide.

[0006] Furthermore, the reducing sugar is one or more of glucose, fructose, lactose, galactose, and maltose; or is a product obtained by hydrolysis of one or more of sucrose, starch, and cellulose.

[0007] When there are multiple reducing sugars, they can be combined in any ratio as needed.

[0008] Furthermore, the amino acid is one or more of glycine, alanine, lysine, tryptophan, histidine, arginine, aspartic acid, glutamic acid, tyrosine and other amino acids.

[0009] When multiple amino acids are used, they can be combined in any ratio as needed.

[0010] Furthermore, the metal oxide is one or more of iron oxide, calcium oxide, copper oxide, and magnesium oxide; the metal hydroxide is iron oxyhydroxide, iron hydroxide, or ferrous hydroxide.

[0011] When multiple metal oxides or metal hydroxides are used, they can be combined in any ratio as needed.

[0012] The present invention also provides a method for preparing the foliar fertilizer for increasing the mineral content of fruits, the specific steps of which are:

[0013] 1) dissolving 1-20 parts by weight of reducing sugar and 1-20 parts by weight of amino acid in 20-80 parts by weight of water, and stirring and dissolving at 40° C.-70° C. for 5-20 minutes;

[0014] 2) adding 1-10 parts by weight of metal oxide or metal hydroxide to step 1), stirring and dissolving at 40° C. to 70° C. for 5-10 minutes;

[0015] 3) reacting the solution obtained in step 2) at 70° C.-180° C. for 4-16 hours;

[0016] 4) After the reaction, the mixture is cooled to room temperature, and the filtrate is separated into solid and liquid to obtain a precipitate, which is the foliar fertilizer.

[0017] The present invention uses amino acids and reducing sugars as raw materials, which are easy to obtain and low in cost. Both the reaction products and unreacted raw materials can be absorbed by plants, and the utilization rate is high. The present invention adopts a Maillard reaction system, a one-pot method and a one-step preparation, and the reaction steps are simple, the production time is short, and the yield is high. The present invention uses metal oxides or metal hydroxides as raw materials to convert difficult-to-use minerals into usable forms, and has the sustainability of recycling. The product of the present invention has higher alkaline stability than similar complexes using metal salts as raw materials, and can be used normally in a strong alkaline environment with pH>10.

[0018] The beneficial effects of the present invention are:

[0019] The foliar fertilizer for increasing the mineral content of fruits provided by the present invention can convert unusable metal oxides into usable forms, and has the sustainability of recycling; amino acids and reducing sugars are used as raw materials, the raw materials are easy to obtain, the cost is low, the reaction steps are simple, the production time is short, the yield is high, and it is environmentally friendly; it has strong alkaline stability, can be used normally in an alkaline environment of pH>10, and can increase the mineral nutrients of fruits by 10%-200%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The stability of Maillard-metal complexes under different pH conditions was determined by UV spectroscopy. DETAILED DESCRIPTION

[0021] The embodiments of the present invention will be described in detail and comprehensively below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0022] my country is a major apple-producing country in the world, ranking first in the world in terms of area and output. Apple has become a pillar industry of the rural economy in the main producing areas, playing an important role in agricultural structural adjustment, increasing farmers' income, and export earnings. However, the degree of soil salinization in apple-growing areas is serious, with an area of ​​about 1.48 billion mu nationwide, concentrated in the five major regions of Northeast, North Central, Northwest, Coastal and North China, of which the saline-alkali area in North China covers more than 10 million mu. The saline-alkali environment will force metal oxidation and precipitation. The higher the soil pH, the greater the frequency and rate of oxidation precipitation. For example, iron ions can be rapidly hydrolyzed and precipitated in a neutral environment to form insoluble oxides. The half-life of iron ions is approximately 5 hours, 1 hour, and 3 minutes at pH 6.0, 7.0, and 8.0, respectively. Under saline-alkali soil conditions, the concentration of soluble iron ions is 10 -10 M, far below the 10 required for plant growth. -8 M. The metal oxides or metal hydroxides formed after the oxidation and precipitation of mineral nutrients are difficult to be absorbed and utilized by plants, resulting in nutrient deficiency, which leads to restricted tree growth and reduced fruit quality, seriously affecting economic benefits. Therefore, apples were used as the application object to test the effect of the foliar fertilizer provided by the present invention.

[0023] Example 1 Preparation of foliar fertilizer using ferrous sulfate and ferrous hydroxide as raw materials

[0024] 1) Dissolve 10 parts of glucose and 20 parts of glutamic acid in 75 parts of water and stir to dissolve at 65°C for 20 minutes;

[0025] 2) adding 5 parts of ferrous sulfate or 5 parts of ferrous hydroxide to step 1), stirring and dissolving at 60° C. for 10 minutes;

[0026] 3) reacting the solution obtained in step 2) at 70° C.-180° C. for 15 hours;

[0027] 4) After the reaction is complete, the mixture is cooled to room temperature. The filtrate is separated into solid and liquid to obtain a precipitate, which is the foliar fertilizer product. In order to distinguish the two, the one with ferrous sulfate added is called Maillard-metal inorganic salt complex, and the one with iron oxide added is called Maillard-metal oxide complex.

[0028] Dissolve 0.5g of the complex sample in 10mL of water, adjust the pH value of the resulting solvent to a fixed value, and after standing for 1h, measure the absorbance of the solvent at a wavelength of 562nm using ultraviolet spectroscopy. The stability of the sample is determined based on the change in absorbance. The same sample was tested in parallel for 3 groups, and the results are as follows: Figure 1 shown.

[0029] from Figure 1 It can be seen that the absorbance of the Maillard-metal oxide complex does not change significantly in the pH range of 3 to 12; the Maillard-metal inorganic salt complex does not change significantly in the pH range of 3 to 9, and the absorbance decreases significantly when pH>9. Figure 1 It can be shown that the two complexes are stable in neutral and acidic environments, the complex obtained from oxides is more stable in alkaline environments, and the complex obtained from inorganic salts is only somewhat stable in weakly alkaline environments, and is less stable in strongly alkaline environments (pH>10). In other words, metal oxide complexes can also be used in environments with strong salinity and alkalinity, and have a wider range of applications.

[0030] Example 2

[0031] 1) Dissolve 10 kg of glucose and 15 kg of glycine in 100 L of water and stir at 40°C for 20 minutes.

[0032] 2) Add 15 kg of iron oxide to the above solution and stir to dissolve at 40°C for 15 minutes.

[0033] 3) The solution obtained in step 2 was heated to 150° C. and condensed and refluxed for 10 hours.

[0034] 4) The solution after the complete reaction was filtered, and the filtrate was subjected to solid-liquid separation by reduced pressure distillation at 40° C. to obtain a dark brown product.

[0035] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing the iron complex.

[0036] Example 3

[0037] 1) Dissolve 10 kg of glucose and 20 kg of lysine in 100 L of water and stir to dissolve at 40°C for 30 minutes.

[0038] 2) Add 20 kg of ferric hydroxide to the above solution and stir to dissolve at 40°C for 15 minutes.

[0039] 3) The solution obtained in step 2 was heated to 180° C. and condensed and refluxed for 16 hours.

[0040] 4) The solution after the complete reaction was filtered, and the filtrate was subjected to solid-liquid separation by reduced pressure distillation at 40° C. to obtain a dark brown product.

[0041] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing the iron complex.

[0042] Example 3

[0043] 1) Dissolve 10 kg of fructose and 20 kg of lysine in 100 L of water and stir to dissolve at 40°C for 30 minutes.

[0044] 2) Add 20 kg of ferric oxyhydroxide to the above solution and stir to dissolve at 40°C for 15 minutes.

[0045] 3) The solution obtained in step 2 was heated to 180° C. and condensed and refluxed for 16 hours.

[0046] 4) The solution after the complete reaction was filtered, and the filtrate was subjected to solid-liquid separation by reduced pressure distillation at 40° C. to obtain a dark brown product.

[0047] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing the iron complex.

[0048] Example 4

[0049] 1) Dissolve 1 kg of glucose and 2 kg of glycine in 10 L of water and stir at 40°C for 30 minutes.

[0050] 2) Add 2 kg of copper chloride to the above solution and stir to dissolve at 40°C for 5 minutes.

[0051] 3) The solution obtained in step 2 was heated to 80° C. and condensed and refluxed for 6 hours.

[0052] 4) The solution after the complete reaction was distilled under reduced pressure at 40° C. to separate the solid from the liquid to obtain a dark brown product.

[0053] 5) Drying the product obtained in step 4 at 80° C. for 30 minutes and cooling to obtain a copper composite.

[0054] Example 6

[0055] 1) Dissolve 1 kg of glucose and 10 kg of lysine in 20 L of water and stir at 40°C for 30 minutes.

[0056] 2) Add 2 kg of copper oxide to the above solution and stir to dissolve at 40°C for 15 minutes.

[0057] 3) The solution obtained in step 2 was heated to 120° C. and condensed and refluxed for 10 hours.

[0058] 4) The solution after the complete reaction was filtered, and the filtrate was subjected to solid-liquid separation by reduced pressure distillation at 40° C. to obtain a dark brown product.

[0059] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing the copper complex.

[0060] Example 5

[0061] 1) Dissolve 10 kg lactose and 30 kg histidine in 100 L water and stir at 40°C for 30 minutes.

[0062] 2) Add 20 kg of magnesium oxide, 10 kg of zinc oxide and 5 kg of calcium oxide to the above solution and stir and dissolve at 40°C for 15 minutes.

[0063] 3) The solution obtained in step 2 was heated to 130° C. and condensed and refluxed for 14 hours.

[0064] 4) The solution after the complete reaction was filtered, and the filtrate was subjected to solid-liquid separation by reduced pressure distillation at 40° C. to obtain a dark brown product.

[0065] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing a magnesium-zinc-calcium complex.

[0066] Example 6

[0067] 1) Dissolve 10 kg of glucose and 20 kg of lysine in 100 L of water and stir to dissolve at 40°C for 30 minutes.

[0068] 2) Add 15 kg of calcium oxide, 15 kg of iron oxide and 15 kg of zinc oxide to the above solution and stir and dissolve at 40°C for 10 minutes.

[0069] 3) The solution obtained in step 2 was heated to 100° C. and condensed and refluxed for 16 hours.

[0070] 4) The solution after the complete reaction was distilled under reduced pressure at 40° C. to separate the solid from the liquid to obtain a dark brown product.

[0071] 5) drying the product obtained in step 4 at 80° C. for 30 minutes and cooling the product to obtain a foliar fertilizer containing a calcium-iron-zinc complex.

[0072] Test Example 1

[0073] The location of the foliar fertilizer effect test: Sijiqing Town, Haidian District, Beijing, has a flat terrain, uniform soil conditions, and a soil pH of 7.5-8.0, which is a weakly alkaline soil.

[0074] Test variety: Apple.

[0075] Experimental design: The experiment selected apple trees with a fruit age of 5 years, and took a mixture of calcium oxide, iron oxide, and zinc oxide in equal proportions as the control group, and took the foliar fertilizer obtained in Example 6 as the experimental group. They were dissolved in water at a mass ratio of 3‰ to prepare solutions, and clean water was used as the blank control group. The apple trees were sprayed once at a dosage of 20 liters per mu in at least one season of spring (May 27), summer (July 26), and autumn (September 27). There were 7 treatments in total, and the spraying season selection is shown in Table 1.

[0076] Table 1

[0077]

[0078] When the fruit was ripe, the metal element content of the apple leaves and fruits was tested by plasma inductively coupled plasma mass spectrometry (ICP-OES) for mineral nutrient analysis. The results are shown in Table 2.

[0079] Table 2

[0080]

[0081] It can be seen from Table 2 that the calcium, iron and zinc contents of the leaves applied with the foliar fertilizer of the present invention are increased by 142.1%, 378.9% and 831.4% respectively compared with the leaves not applied with the foliar fertilizer; the calcium, iron and zinc contents of the fruits not applied with the foliar fertilizer are increased by 314.3%, 651.9% and 124.5% respectively. At the same time, the calcium, iron and zinc contents of the leaves and fruits are higher when the foliar fertilizer is applied than when the general mineral element compounds are applied, indicating that the foliar fertilizer provided by the present invention has a better effect.

[0082] It can be seen from the above examples that the foliar fertilizer for increasing the mineral content of fruits provided by the present invention converts metal oxides and metal hydroxides that are difficult for plants to utilize into usable forms, thereby increasing the absorption efficiency of mineral nutrients. The raw materials of the product are easily available, the cost is low, the reaction steps are simple, the production time is short, the yield is high, and it can be used normally in an alkaline environment, and it has the sustainability of recycling, which has very important economic value for improving the quality of apples grown in salinized land in apple producing areas.

[0083] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A foliar fertilizer for increasing the mineral content of fruits, characterized in that: The invention is prepared by Maillard reaction of 1-20 parts by weight of reducing sugar, 1-20 parts by weight of amino acid, 20-80 parts by weight of water and 1-10 parts by weight of metal oxide or metal hydroxide.

2. The foliar fertilizer for improving the mineral content of fruits as claimed in claim 1, characterized in that: The reducing sugar is one or more of glucose, fructose, lactose, galactose, and maltose; or is a product obtained by hydrolysis of one or more of sucrose, starch, and cellulose.

3. The foliar fertilizer for improving the mineral content of fruits as claimed in claim 1, characterized in that: The amino acid is one or more of glycine, alanine, lysine, tryptophan, histidine, arginine, aspartic acid, glutamic acid, and tyrosine.

4. The foliar fertilizer for improving the mineral content of fruits as claimed in claim 1, characterized in that: The metal oxide is one or more of iron oxide, calcium oxide, copper oxide and magnesium oxide; the metal hydroxide is iron oxyhydroxide, iron hydroxide or ferrous hydroxide.

5. The method for preparing a foliar fertilizer for increasing the mineral content of fruits as claimed in any one of claims 1 to 4, characterized in that: The specific steps are: 1) dissolving 1-20 parts by weight of reducing sugar and 1-20 parts by weight of amino acid in 20-80 parts by weight of water, and stirring and dissolving at 40° C.-70° C. for 5-20 minutes; 2) adding 1-10 parts by weight of metal oxide or metal hydroxide to step 1), stirring and dissolving at 40° C. to 70° C. for 5-10 minutes; 3) reacting the solution obtained in step 2) at 70° C.-180° C. for 4-16 hours; 4) After the reaction, the mixture is cooled to room temperature, and the filtrate is separated into solid and liquid to obtain a precipitate, which is the foliar fertilizer.

6. The method for using the foliar fertilizer for increasing the mineral content of fruits according to any one of claims 1 to 4, characterized in that: Before use, dissolve the foliar fertilizer in water to a solution with a mass percentage concentration of 0.01%-0.5%, and spray it on the leaves at 20 liters per mu.

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