Amino acid compound foliar fertilizer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of fertilizers, and particularly discloses an amino acid compound foliar fertilizer as well as a preparation method and application thereof. The amino acid compound foliar fertilizer is prepared from L-alanine, L-serine, amino acid microspheres, citric acid-chitosan modified charcoal, lanthanum nitrate, cerous nitrate, Tween 80, ethylene glycol and water, wherein the amino acid microspheres contain L-valine and L-leucine. The amino acid compound foliar fertilizer provided by the invention can prolong the retention period of nutrients on the surfaces of crop leaves, reduce the degradation of the nutrients due to environmental factors and ensure continuous supply of the nutrients, and meanwhile, the amino acid compound foliar fertilizer has excellent stable dispersibility, can prevent the nutrients from gathering in a system to form a local high-concentration area, and can improve the yield of the crops. In addition, the amino acid compound foliar fertilizer meets the requirement for rapid supplement of nutrients in the key growth period of the crops, and the core problems that a traditional foliar fertilizer is short in nutrient retention, poor in stability and prone to aggregation are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fertilizers, and specifically discloses an amino acid compound foliar fertilizer, a preparation method and application thereof. BACKGROUND

[0002] Foliar fertilizer is a fertilizer used as a supplement to soil fertilization in the field of fertilizers. Its core advantage lies in that nutrients can be directly absorbed by crops through the leaves, and it has the characteristic of fast nutrient absorption speed compared to soil fertilization, and can adapt to the nutrient needs of crops at different growth stages, thereby assisting in improving the photosynthetic efficiency and growth quality of crops, and playing an important role in supplementing nutrients in agricultural production.

[0003] However, the existing foliar fertilizer products have short nutrient retention periods, and the nutrients are easily lost quickly. Obvious nutrient loss usually occurs in 7-10 days, which leads to the need for frequent re-spraying, thereby increasing the labor operation cost, and possibly causing insufficient nutrient supply to crops during the critical growth period due to the failure to re-spray in time. At the same time, the existing foliar fertilizer products have poor nutrient stability. Under strong light and other natural environmental conditions, the effective components in the products are easily degraded, with a degradation rate of up to 30%, which leads to a decrease in the effective nutrient content actually acting on crops, thereby directly affecting the fertilization effect. In addition, the existing foliar fertilizer nutrients are prone to aggregation, which easily causes local high concentration during application, thereby having an inhibitory effect on the photosynthetic efficiency of crops, and even adversely affecting the growth of crops. Therefore, how to provide a foliar fertilizer with long action time, good stability and good dispersion effect has become a technical problem to be solved in the field. SUMMARY

[0004] In view of the problems of short nutrient retention period, poor stability and easy aggregation of nutrients in the prior art, the present application provides an amino acid compound foliar fertilizer, a preparation method and application thereof. The amino acid compound foliar fertilizer comprises L-alanine, L-serine, amino acid microspheres, citric acid-chitosan modified biochar, lanthanum nitrate, cerium nitrate, Tween 80, ethylene glycol and water, wherein the amino acid microspheres contain L-valine and L-leucine. The present application cooperates the slow-release effect of the amino acid microspheres with the adsorption and stability characteristics of the citric acid-chitosan modified biochar, thereby prolonging the nutrient retention period, reducing the degradation rate of effective components under strong light, improving the nutrient dispersion to avoid local high concentration, improving the photosynthetic efficiency and growth quality of crops, and meeting the nutrient supplement needs of crops at different growth stages.

[0005] The present application provides an amino acid compound foliar fertilizer, a preparation method and application thereof, which adopt the following technical scheme:

[0006] The present application provides an amino acid compound foliar fertilizer, a preparation method and application thereof, which adopt the following technical scheme:

[0007] L-alanine 1.8-2.2 parts, L-serine 1.2-1.5 parts, amino acid microspheres 3.5-4.5 parts, citric acid-chitosan modified biochar 8.0-9.0 parts, lanthanum nitrate 0.2-0.3 parts, cerium nitrate 0.2-0.3 parts, Tween 80 0.8-1.2 parts, ethylene glycol 1.8-2.2 parts, and water 73-75 parts;

[0008] The amino acid microspheres contain L-valine 0.9-1.3 parts and L-leucine 0.7-0.9 parts.

[0009] In the present application, the amino acid microspheres act as slow-release nutrient units, slowly release the amino acids in the core material, extend the nutrient retention period, and thus reduce the frequency of supplementary spraying and labor costs. At the same time, the amino acid microspheres can to some extent avoid environmental influences, avoid the oxidative degradation of L-valine and L-leucine due to environmental influences, and ensure the continuous effect of effective nutrients on crops.

[0010] In the present application, L-valine and L-leucine in the amino acid microspheres can be absorbed through the stomata and cuticle of the leaf epidermis. L-valine, as an essential amino acid that crops cannot synthesize themselves, can directly participate in protein synthesis in leaves and fruits, providing basic substances for cell division and tissue growth, and can also activate nitrate reductase activity to promote the absorption and transformation of lanthanum nitrate and cerium nitrate. L-leucine is an important precursor for crop energy metabolism, can participate in the tricarboxylic acid cycle to provide energy for photosynthesis, and can also promote leaf expansion and root development. The addition of L-valine and L-leucine can meet the nutritional needs of crops from the seedling stage to the flowering and fruiting stage.

[0011] In the present application, the citric acid-chitosan modified biochar acts as a nutrient adsorption and dispersion carrier. This kind of citric acid-chitosan modified biochar has a porous structure, can adsorb nutrients, and slow down the release rate of nutrients. At the same time, the citric acid-chitosan modified biochar has good compatibility with other components and good dispersibility in foliar fertilizers. In addition, the citric acid-chitosan modified biochar can adjust the surface charge to avoid the formation of local high concentration areas due to the aggregation of components such as L-alanine and lanthanum nitrate, and to avoid the problem of nutrient aggregation.

[0012] In the present application, L-alanine and L-serine can be absorbed through the stomata and cuticle of the leaf epidermis. L-alanine can directly participate in the photosynthetic carbon metabolism process of crops, providing carbon skeletons for chlorophyll synthesis and improving photosynthetic rate. L-serine is a precursor of cysteine, phospholipids and other substances in crops, can promote enzyme activity, and assist crops in coping with the peak of nutrient demand during the growth period. The addition of L-alanine and L-serine can meet the rapid nutritional supplement needs of crops during the key growth period.

[0013] In this invention, lanthanum nitrate and cerium nitrate, as rare earth element regulating components, can dissociate into La in aqueous solution. 3+ and Ce 3+ La 3+ and Ce 3+ It can bind to carrier proteins on leaf cell membranes, regulate cell membrane permeability, and enhance the absorption efficiency of amino acids and trace elements by leaves; at the same time, La 3+ and Ce 3+ It can enhance the stability of photosystem II (PSII) in chloroplasts, reduce photo-oxidative damage to chloroplasts under strong light conditions, indirectly improve crop stress resistance, and prevent a decline in nutrient absorption efficiency caused by environmental stress. Additionally, La... 3+ and Ce 3+ It can also promote crop root development, indirectly enhance the underground part's ability to absorb soil nutrients, and further improve the overall effect of fertilization.

[0014] In this invention, Tween 80, as a non-ionic surfactant, spontaneously aligns its hydrophilic groups (polyoxyethylene chains) and hydrophobic groups (alkyl chains) at the aqueous interface in the amino acid compound foliar fertilizer. The hydrophilic groups face the aqueous phase and bind with water molecules through hydrogen bonds or van der Waals forces, while the hydrophobic groups move away from the aqueous phase and face the amino acid microspheres, citric acid-chitosan modified biochar, and other components in the system, forming a stable molecular adsorption layer. This breaks the originally tight hydrogen bond network of water molecules, reduces the mutual attraction between molecules on the aqueous phase surface, lowers the surface tension of the amino acid compound foliar fertilizer, and promotes the uniform dispersion of easily aggregated components such as lanthanum nitrate and cerium nitrate in the amino acid compound foliar fertilizer, avoiding excessively high local concentrations. At the same time, it enhances the wettability of the foliar fertilizer on the surface of crop leaves, making it easier for the amino acid compound foliar fertilizer to spread and form a continuous film on the leaf surface, reducing the problem of droplet aggregation and rolling due to excessive surface tension, and prolonging the effect time of nutrients on the leaf surface.

[0015] In this invention, ethylene glycol serves as a synergistic component for moisturizing and solubilizing. The hydroxyl groups in its molecular structure can form hydrogen bonds with water molecules, creating a moisturizing layer on the leaf surface and prolonging the wetting time, thus providing sufficient time for nutrient penetration and absorption. Simultaneously, as a polar solvent, ethylene glycol can form coordination compounds with lanthanum nitrate and cerium nitrate, enhancing their solubility in water and preventing precipitate formation of lanthanum nitrate and cerium nitrate during low temperatures or static conditions, thereby improving the stability of the amino acid compound foliar fertilizer.

[0016] Preferably, the method for preparing the amino acid microspheres includes the following steps:

[0017] S1, the bagasse is dried and crushed, then mixed with sodium hydroxide solution, stirred and reacted at 85-95℃, filtered, the filtrate is adjusted to pH=2.0-2.5 with hydrochloric acid, and then precipitate is obtained by standing at 25-35℃;

[0018] S2, the lignin precipitate, citric acid and water are mixed, stirred and reacted at 35-40℃, and then emulsified by shearing at 25-35℃ to obtain an alkali lignin-citric acid complex;

[0019] S3, the alkali lignin-citric acid complex, trehalose and water are mixed, and then stirred and reacted at 25-35℃ to obtain a coating solution;

[0020] S4, L-valine and L-leucine are mixed, and then stirred and dissolved at 35-45℃ to obtain a core material mother liquor;

[0021] S5, the coating solution and the core material mother liquor are mixed, emulsified by shearing at 25-35℃, and then calcium chloride is added, and stirred at 30-40℃ to obtain amino acid microspheres.

[0022] In S1, the sodium hydroxide solution can break the bonds between lignin, cellulose and hemicellulose in the bagasse, and then the lignin is precipitated by hydrochloric acid to have complete functional groups such as phenolic hydroxyl and methoxyl, and the lignin molecular chain has a rigid structure, which can be used as the skeleton of the coating layer to avoid the structure collapse of the subsequent microspheres during storage or spraying.

[0023] In S2, the esterification reaction occurs between the carboxyl group of citric acid and the hydroxyl group of lignin during the stirring reaction, and additional carboxyl groups are introduced into the lignin molecular chain to make the lignin have strong hydrogen bonding ability and crosslinking reactivity, and the alkali lignin-citric acid is broken into small particles by shearing emulsification to increase the contact area with trehalose.

[0024] In S3, trehalose is filled in the lignin molecule during the stirring reaction, and the hydroxyl groups in trehalose can be connected to the carboxyl and hydroxyl groups in the alkali lignin-citric acid through hydrogen bonds to form a trehalose-alkali lignin-citric acid complex with good stability.

[0025] In S4, L-valine and L-leucine are dissolved by stirring at 35-45℃, and this temperature can promote the complete dissolution of L-valine and L-leucine to form a core material mother liquor with uniform concentration and avoid the residual of amino acid crystals.

[0026] In S5, the core material mother liquor is broken into small droplets by shearing emulsification, and the coating solution is uniformly wrapped around the surface of the core material droplets under the adsorption of polar functional groups, and when calcium chloride is added, the Ca2+ The coordination cross-linking reaction occurs with the carboxyl in the coating liquid, and the hydrogen bond in the coating liquid is converted into a coordination bond to form a dense coating layer containing micropores.

[0027] The coating layer of the amino acid microspheres prepared by the preparation method has a dense three-dimensional cross-linked network. The rigid molecular chains of the lignin in the network structure can resist the osmotic pressure of water in the storage environment (anhydrous circulation environment). The dual action of the coordination bond and the hydrogen bond further prevents the molecular chains of the shell from loosening, allowing only a small amount of water molecules to slowly penetrate into the micropores inside the shell. At the same time, the hydroxyl groups in the molecular structure of the ethylene glycol in the amino acid complex foliar fertilizer form hydrogen bonds with the hydroxyl groups of the fucose on the coating layer of the amino acid microspheres, constructing a weak adsorption barrier on the surface of the amino acid microsphere coating layer, slowing down the penetration rate of water molecules in the storage environment (anhydrous circulation environment) into the interior of the coating layer. In addition, Tween 80 in the amino acid complex foliar fertilizer can be adsorbed on the surface of the amino acid microspheres, with the hydrophilic group facing the water phase and the hydrophobic group facing the shell, forming a dispersion protection film. In the storage environment (anhydrous circulation environment), the amino acid microspheres are prevented from agglomerating due to intermolecular attraction, resulting in excessive local water concentration, and thus preventing premature release of amino acids caused by excessive local infiltration. The present application ensures that the amino acid microspheres remain in a stable state with trace amounts of water contact and no amino acid dissolution during the storage process of the amino acid complex foliar fertilizer, achieving the effect of preventing the premature release of amino acids during storage.

[0028] The anhydrous circulation environment is formed by the sealed packaging of the amino acid complex foliar fertilizer provided by the present application. The sealed packaging uses packaging means commonly used in the art with moisture-proof and air-proof properties, thereby blocking the contact of the amino acid complex foliar fertilizer with free water, water vapor and air in the external environment.

[0029] After the amino acid compound foliar fertilizer provided by the application is sprayed on the leaf surface, in the water circulation environment formed by the leaf residual water, atmospheric humidity and leaf transpiration, the hydrogen bond binding force of the hydrogen bond connecting ethylene glycol of the amino acid microspheres will be weakened by the circulating water, and at the same time, the ethylene glycol forming the hydrogen bond with the circulating water will be separated from the surface of the amino acid microspheres, finally leading to the destruction of the weak adsorption barrier of ethylene glycol, avoiding hindering the contact of water molecules with the amino acid microspheres. Similarly, in the water circulation environment formed by the leaf residual water, atmospheric humidity and leaf transpiration, the hydrophilic group of Tween 80 adsorbed on the surface of the amino acid microspheres forms a hydrogen bond with the circulating water, and with the circulation of the circulating water, the hydrophobic group of Tween 80 is still combined with the amino acid microspheres, while the hydrophilic group of Tween 80 is dragged by the circulating water, so that the hydrophobic end of Tween 80 is combined with the amino acid microspheres, and the hydrophilic end is stretched with the circulation of the circulating water, thereby making the dense and dispersed protective film of Tween 80 on the surface of the amino acid microspheres have a certain gap, ensuring that the amino acid microspheres can be fully soaked in water in the water circulation environment, and then making water penetrate into the inside of the amino acid microspheres. With the destruction of the weak adsorption barrier of ethylene glycol, the existence of the gap in the dispersion protective film of Tween 80, and the full entry of water into the structure of the amino acid microspheres, the micropores on the surface of the amino acid microspheres are completely soaked and filled with water, forming an amino acid dissolution channel, under the action of temperature fluctuation and water circulation, the amino acids in the amino acid microspheres are continuously and slowly released, and finally the complete release of the amino acids is realized.

[0030] Preferably, in S1, the mass-volume ratio of the bagasse and the aqueous sodium hydroxide solution is 1g:(10-15)mL, and the mass percentage content of the aqueous sodium hydroxide solution is 1%-3%.

[0031] Preferably, in S2, the mass-volume ratio of the lignin precipitate, citric acid and water is 1g:(0.05-0.15)g:(5-6)mL.

[0032] Preferably, in S3, the mass-volume ratio of the alkali lignin-citric acid complex, trehalose and water is 1g:(0.6-0.7)g:(7-8)mL.

[0033] Preferably, in S4, the mass-volume ratio of the L-valine, L-leucine and water is 1g:(0.7-0.8)g:(7.5-8.5)mL.

[0034] Preferably, in S5, the volume ratio of the coating liquid and the core material mother liquor is (2-4):1.

[0035] Preferably, in S5, the volume-mass ratio of the core material mother liquor and calcium chloride is 1mL:(0.005-0.015)g.

[0036] Preferably, in S1, the stirring speed is 200 r / min-500 r / min, and the stirring time is 2 h-4 h.

[0037] Preferably, in S1, the stirring speed is 200 r / min-500 r / min, and the stirring time is 2 h-4 h.

[0038] Preferably, in S2, the stirring speed is 400 r / min-600 r / min, and the stirring time is 0.5 h-1.5 h.

[0039] Preferably, in S2, the shearing emulsification speed is 18000 r / min-22000 r / min, and the shearing emulsification time is 10 min-20 min.

[0040] Preferably, in S3, the stirring speed is 400 r / min-600 r / min, and the stirring time is 15 min-45 min.

[0041] Preferably, in S4, the stirring speed is 400 r / min-600 r / min, and the stirring time is 15 min-45 min.

[0042] Preferably, in S5, the shearing emulsification speed is 13000 r / min-17000 r / min, and the shearing emulsification time is 5 min-15 min.

[0043] Preferably, in S5, the stirring speed is 400 r / min-600 r / min, and the stirring time is 20 min-40 min.

[0044] Preferably, the preparation method of the citric acid-chitosan modified biochar comprises the following steps:

[0045] Step 1, corn straw biochar is dried and crushed, then mixed with phosphoric acid aqueous solution, and stirred at 55-65 DEG C to obtain a preliminary modified biochar;

[0046] Step 2, the preliminary modified biochar, citric acid, chitosan and water are mixed, and stirred at 45-55 DEG C to obtain a citric acid-chitosan modified biochar.

[0047] In step 1, under the mild etching of phosphoric acid, the amorphous impurities and part of the inert components on the surface of the corn straw biochar are dissolved, forming a porous structure, which increases the specific surface area of the corn straw biochar, and increases the content of functional groups such as hydroxyl and phosphoric acid groups on the surface of the corn straw biochar.

[0048] In step 2, the carboxyl group of citric acid forms an ester bond or a hydrogen bond with the hydroxyl group and the phosphoric acid group on the surface of the primary modified biochar, and an amidation reaction occurs with the amino group of chitosan, thereby forming a citric acid-chitosan modified biochar composite structure. The citric acid-chitosan modified biochar can fix the amino acid microspheres by adsorption to prevent the microspheres from agglomerating, and can also fix the free components by adsorption to achieve slow release of the free components during application.

[0049] Preferably, in step 1, the mass-volume ratio of the corn straw biochar and the aqueous phosphoric acid solution is 1g:(8-12)mL, and the mass percentage of the aqueous phosphoric acid solution is 3%-7%.

[0050] Preferably, in step 2, the mass-volume ratio of the primary modified biochar, citric acid, chitosan and water is 1g:(0.03-0.05)g:(0.02-0.03)g:(7-9)mL.

[0051] Preferably, in step 1, the stirring speed of the reaction is 400r / min-600r / min, and the time is 3h-5h.

[0052] Preferably, in step 2, the stirring speed is 400r / min-600r / min, and the time is 0.5h-1.5h.

[0053] The second aspect of the present application provides a preparation method of the amino acid composite foliar fertilizer described in the foregoing scheme, wherein the preparation method of the amino acid composite foliar fertilizer comprises the following steps:

[0054] Step one, mixing the amino acid microspheres, citric acid-chitosan modified biochar and water, and stirring at 30℃-40℃ to obtain a slow-release mixture;

[0055] Step two, mixing the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol, stirring at 30℃-40℃, and then shear emulsifying at 25℃-35℃ to obtain the amino acid composite foliar fertilizer.

[0056] The preparation method provided by the present application is mild and does not use high-temperature treatment, thereby avoiding the destruction of the structure of the amino acid microspheres and the activity of the nutrients, and at the same time, the step-by-step mixing can make the amino acid microspheres fully combine with the citric acid-chitosan modified biochar, ensure the dispersion stability of the system, and reduce the agglomeration of the microspheres. In addition, the preparation method provided by the present application can be completed by step-by-step mixing and normal-temperature stirring, without the need for special and complex equipment, and the operation is simple and stable, and is suitable for large-scale production.

[0057] Preferably, in step one, the stirring speed is 400r / min-600r / min, and the time is 15min-45min.

[0058] Preferably, in step two, the stirring speed is 400r / min-600r / min, and the time is 30min-40min.

[0059] Preferably, in step two, the shearing emulsification speed is 2800r / min-3200r / min, and the time is 15min-25min.

[0060] The third aspect of the present application provides the application of the amino acid compound foliar fertilizer in foliar fertilizers.

[0061] In summary, the present application provides an amino acid compound foliar fertilizer, which is composed of L-alanine, L-serine, amino acid microspheres, citric acid-chitosan modified biochar, lanthanum nitrate, cerium nitrate, Tween 80, ethylene glycol and water, wherein the amino acid microspheres contain L-valine and L-leucine. The amino acid compound foliar fertilizer provided by the present application can prolong the retention period of nutrients on the surface of crop leaves, reduce the degradation of nutrients due to environmental factors, and ensure the continuous supply of nutrients. At the same time, the amino acid compound foliar fertilizer has excellent stable dispersibility, which can avoid the aggregation of nutrients in the system to form a local high concentration area, reduce the impact on crop growth, and additionally, the amino acid compound foliar fertilizer meets the rapid replenishment demand of nutrients in the key growth period of crops, solving the core problems of short nutrient retention, poor stability and easy aggregation of traditional foliar fertilizers.

[0062] Meanwhile, the present application also provides a preparation method of the amino acid compound foliar fertilizer, which is prepared by step-by-step mixing and mild conditions, without special and complex equipment, and is simple and stable to operate, can avoid the destruction of nutrient activity, and is suitable for large-scale production.

[0063] In addition, the present application also provides an application mode of the amino acid compound foliar fertilizer in foliar fertilizers, which can realize the rapid replenishment and long-term supply of crop nutrients, and solve the problems of fast nutrient loss and poor stability of traditional foliar fertilizers. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only one embodiment of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0065] Example 1

[0066] The embodiment provides an amino acid compound foliar fertilizer and a preparation method thereof, and specifically comprises the following contents.

[0067] The amino acid compound foliar fertilizer comprises the following components in parts by mass:

[0068] L-alanine 1.8 parts, L-serine 1.2 parts, amino acid microspheres 3.5 parts, citric acid-chitosan modified biochar 8.0 parts, lanthanum nitrate 0.2 parts, cerium nitrate 0.2 parts, Tween 80 0.8 parts, ethylene glycol 1.8 parts and water 73 parts;

[0069] The amino acid microspheres contain 0.9 parts of L-valine and 0.7 parts of L-leucine.

[0070] The preparation method of the amino acid microspheres comprises the following steps:

[0071] S1, 10g of bagasse is dried and crushed, and then mixed with 10mL of a 1% sodium hydroxide aqueous solution; under the condition of 85°C and 200r / min, the mixture is stirred for 2h, then filtered, and the filtrate is obtained; the pH value of the filtrate is adjusted to 2.0 by using hydrochloric acid, and then the mixture is placed at 25°C for 2h to obtain a lignin precipitate;

[0072] S2, 10g of the lignin precipitate, 0.5g of citric acid and 50mL of water are mixed, and then the mixture is stirred at 35°C and 400r / min for 0.5h; then the mixture is sheared and emulsified at 25°C and 18000r / min for 10min to obtain an alkali lignin-citric acid compound;

[0073] S3, 10g of the alkali lignin-citric acid compound, 6g of trehalose and 70mL of water are mixed, and then the mixture is stirred at 25°C and 400r / min for 15min to obtain a coating liquid;

[0074] S4, 1g of L-valine, 0.7g of L-leucine and 7.5mL of water are mixed, and then the mixture is stirred at 35°C and 400r / min for 15min to obtain a core material mother liquor;

[0075] S5, 20mL of the coating liquid and 10mL of the core material mother liquor are mixed, and then the mixture is sheared and emulsified at 25°C and 13000r / min for 5min; then 0.05g of calcium chloride is added, and the mixture is stirred at 30°C and 400r / min for 20min to obtain amino acid microspheres.

[0076] The preparation method of the citric acid-chitosan modified biochar comprises the following steps:

[0077] Step 1, 10g of corn straw biochar was dried and crushed, then mixed with 80mL of phosphoric acid aqueous solution, and stirred at 55℃ and 400r / min for 3h to obtain the initial modified biochar;

[0078] Step 2, the 10g of initial modified biochar, 0.3g of citric acid, 0.2g of chitosan and 70mL of water were mixed, and stirred at 45℃ and 400r / min for 0.5h to obtain the citric acid-chitosan modified biochar.

[0079] The preparation method of the amino acid compound foliar fertilizer comprises the following steps:

[0080] Step 1, the amino acid microspheres, the citric acid-chitosan modified biochar and water were mixed, and stirred at 30℃ and 400r / min for 15min to obtain a slow-release mixture;

[0081] Step 2, the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol were mixed, and stirred at 30℃ and 400r / min for 30min, and then sheared and emulsified at 25℃ and 2800r / min for 15min to obtain the amino acid compound foliar fertilizer.

[0082] Example 2

[0083] The present embodiment provides an amino acid compound foliar fertilizer and a preparation method thereof, which specifically comprises the following contents:

[0084] The amino acid compound foliar fertilizer comprises the following components in parts by mass:

[0085] L-alanine 2.2 parts, L-serine 1.5 parts, amino acid microspheres 4.5 parts, citric acid-chitosan modified biochar 9.0 parts, lanthanum nitrate 0.3 parts, cerium nitrate 0.3 parts, Tween 80 1.2 parts, ethylene glycol 2.2 parts and water 75 parts;

[0086] The amino acid microspheres contain L-valine 1.3 parts and L-leucine 0.9 parts.

[0087] The preparation method of the amino acid microspheres comprises the following steps:

[0088] S1, 10g of sugarcane bagasse was dried and crushed, then mixed with 15mL of 3% mass percentage sodium hydroxide aqueous solution, and stirred at 95℃ and 500r / min for 4h, then filtered, and the filtrate was adjusted to pH=2.5 with hydrochloric acid and placed at 35℃ for 4h to obtain a lignin precipitate;

[0089] S2, 10 g of lignin, 1.5 g of citric acid and 60 mL of water were mixed, stirred at 40℃ and 600 r / min for 1.5 h, and then sheared and emulsified at 35℃ and 22000 r / min for 20 min to obtain an alkali lignin-citric acid complex;

[0090] S3, 10 g of the alkali lignin-citric acid complex, 7 g of trehalose and 80 mL of water were mixed, stirred at 35℃ and 600 r / min for 45 min to obtain a coating solution;

[0091] S4, 1 g of L-valine, 0.8 g of L-leucine and 8.5 mL of water were mixed, stirred at 45℃ and 600 r / min for 45 min to obtain a core material mother liquor;

[0092] S5, 40 mL of the coating solution and 10 mL of the core material mother liquor were mixed, sheared and emulsified at 35℃ and 17000 r / min for 15 min, then 0.15 g of calcium chloride was added, and stirred at 40℃ and 600 r / min for 40 min to obtain amino acid microspheres.

[0093] The preparation method of the citric acid-chitosan modified biochar comprises the following steps:

[0094] Step 1, 10 g of corn straw biochar was dried and crushed, mixed with 120 mL of phosphoric acid aqueous solution, and stirred at 65℃ and 600 r / min for 5 h to obtain a preliminary modified biochar;

[0095] Step 2, 10 g of the preliminary modified biochar, 0.5 g of citric acid, 0.3 g of chitosan and 90 mL of water were mixed, stirred at 55℃ and 600 r / min for 1.5 h to obtain a citric acid-chitosan modified biochar.

[0096] The preparation method of the amino acid compound foliar fertilizer comprises the following steps:

[0097] Step one, the amino acid microspheres, the citric acid-chitosan modified biochar and water were mixed, stirred at 40℃ and 600 r / min for 45 min to obtain a slow-release mixture;

[0098] Step two, the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol were mixed, stirred at 40℃ and 600 r / min for 40 min, and then sheared and emulsified at 35℃ and 3200 r / min for 25 min to obtain an amino acid compound foliar fertilizer.

[0099] Example 3

[0100] The embodiment provides an amino acid compound foliar fertilizer and a preparation method thereof, and specifically comprises the following contents.

[0101] The amino acid compound foliar fertilizer comprises the following components in parts by mass:

[0102] 2 parts of L-alanine, 1.3 parts of L-serine, 4 parts of amino acid microspheres, 8.5 parts of citric acid-chitosan modified biochar, 0.25 part of lanthanum nitrate, 0.25 part of cerium nitrate, 1 part of Tween 80, 2 parts of ethylene glycol and 74 parts of water;

[0103] The amino acid microspheres contain 1.1 parts of L-valine and 0.8 parts of L-leucine.

[0104] The preparation method of the amino acid microspheres comprises the following steps:

[0105] S1, 10g of bagasse is dried and crushed, and then mixed with 13mL of a 2% sodium hydroxide aqueous solution; under the condition of 90 DEG C and 350r / min, the mixture is stirred for 3h, then filtered, and the filtrate is obtained; the pH value of the filtrate is adjusted to 2.3 by using hydrochloric acid, and the mixture is placed at 30 DEG C for 3h to obtain a lignin precipitate;

[0106] S2, 10g of the lignin precipitate, 1g of citric acid and 55mL of water are mixed, and the mixture is stirred at 37 DEG C and 500r / min for 1h, and then sheared and emulsified at 30 DEG C and 20000r / min for 15min to obtain an alkali lignin-citric acid compound;

[0107] S3, 10g of the alkali lignin-citric acid compound, 6.5g of trehalose and 75mL of water are mixed, and the mixture is stirred at 30 DEG C and 500r / min for 30min to obtain a coating liquid;

[0108] S4, 1g of L-valine, 0.75g of L-leucine and 8mL of water are mixed, and the mixture is stirred at 40 DEG C and 500r / min for 30min to obtain a core material mother liquor;

[0109] S5, 30mL of the coating liquid and 10mL of the core material mother liquor are mixed, and the mixture is sheared and emulsified at 30 DEG C and 15000r / min for 10min, then 0.1g of calcium chloride is added, and the mixture is stirred at 35 DEG C and 500r / min for 30min to obtain amino acid microspheres.

[0110] The preparation method of the citric acid-chitosan modified biochar comprises the following steps:

[0111] Step 1, 10g of corn straw biochar is dried and crushed, and then mixed with 100mL of a phosphoric acid aqueous solution; under the condition of 60 DEG C and 500r / min, the mixture is stirred for 4h to obtain a primary modified biochar.

[0112] Step 2, after mixing the 10g initial modified biochar, 0.4g citric acid, 0.25g chitosan and 80mL water, stirring at 50℃, 500r / min for 1h, citric acid-chitosan modified biochar was obtained.

[0113] The preparation method of the amino acid compound foliar fertilizer comprises the following steps:

[0114] Step one, after mixing the amino acid microspheres, citric acid-chitosan modified biochar and water, stirring at 35℃, 500r / min for 30min, a slow-release mixture was obtained;

[0115] Step two, after mixing the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol, stirring at 35℃, 500r / min for 35min, then shearing emulsification at 30℃, 3000r / min for 20min, an amino acid compound foliar fertilizer was obtained.

[0116] Comparative Example 1

[0117] The present comparative example provides an amino acid compound foliar fertilizer and a preparation method thereof, which specifically comprises the following contents:

[0118] The amino acid compound foliar fertilizer comprises the following components in mass fraction:

[0119] L-alanine 2 parts, L-serine 1.3 parts, citric acid-chitosan modified biochar 8.5 parts, lanthanum nitrate 0.25 parts, cerium nitrate 0.25 parts, Tween 80 1 part, ethylene glycol 2 parts and water 74 parts.

[0120] The preparation method of the citric acid-chitosan modified biochar comprises the following steps:

[0121] Step 1, after drying and crushing 10g corn straw biochar and mixing with 100mL phosphoric acid aqueous solution, stirring at 60℃, 500r / min for 4h, an initial modified biochar was obtained;

[0122] Step 2, after mixing the 10g initial modified biochar, 0.4g citric acid, 0.25g chitosan and 80mL water, stirring at 50℃, 500r / min for 1h, citric acid-chitosan modified biochar was obtained.

[0123] The preparation method of the amino acid compound foliar fertilizer comprises the following steps:

[0124] Step one, after mixing the citric acid-chitosan modified biochar and water, stirring at 35℃, 500r / min for 30min, a slow-release mixture was obtained;

[0125] Step two, after mixing the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol, stirring at 35℃, 500r / min for 35min, then shearing emulsification at 30℃, 3000r / min for 20min, the amino acid compound foliar fertilizer was obtained.

[0126] Comparative example 2

[0127] The present comparative example provides an amino acid compound foliar fertilizer and a preparation method thereof, which specifically comprises the following contents:

[0128] The amino acid compound foliar fertilizer comprises the following components by mass fraction:

[0129] L-alanine 2 parts, L-serine 1.3 parts, amino acid microspheres 4 parts, lanthanum nitrate 0.25 parts, cerium nitrate 0.25 parts, Tween 80 1 part, ethylene glycol 2 parts and water 74 parts.

[0130] The amino acid microspheres contain L-valine 1.1 parts and L-leucine 0.8 parts.

[0131] The preparation method of the amino acid microspheres comprises the following steps:

[0132] S1, 10g of sugarcane residue was dried and crushed, then mixed with 13mL of 2% mass percentage sodium hydroxide aqueous solution, stirred at 90℃, 350r / min for 3h, then filtered, the filtrate was taken and the pH was adjusted to 2.3 with hydrochloric acid, and then the mixture was placed at 30℃ for 3h to obtain a lignin precipitate;

[0133] S2, 10g of the lignin precipitate, 1g of citric acid and 55mL of water were mixed, stirred at 37℃, 500r / min for 1h, then sheared and emulsified at 30℃, 20000r / min for 15min to obtain an alkali lignin-citric acid complex;

[0134] S3, 10g of the alkali lignin-citric acid complex, 6.5g of trehalose and 75mL of water were mixed, stirred at 30℃, 500r / min for 30min to obtain a coating liquid;

[0135] S4, 1g of L-valine, 0.75g of L-leucine and 8mL of water were mixed, stirred at 40℃, 500r / min for 30min to obtain a core material mother liquor;

[0136] S5, 30 mL of the coating liquid and 10 mL of the core material mother liquor were mixed, and then sheared and emulsified at 30 DEG C and 15000 r / min for 10 min, 0.1 g of calcium chloride was added, and then stirred at 35 DEG C and 500 r / min for 30 min to obtain the amino acid microspheres.

[0137] The preparation method of the amino acid compound foliar fertilizer comprises the following steps:

[0138] Step one, the amino acid microspheres and water were mixed, and then stirred at 35 DEG C and 500 r / min for 30 min to obtain a slow-release mixture;

[0139] Step two, the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol were mixed, and then stirred at 35 DEG C and 500 r / min for 35 min, and then sheared and emulsified at 30 DEG C and 3000 r / min for 20 min to obtain the amino acid compound foliar fertilizer.

[0140] The amino acid compound foliar fertilizers prepared by Examples 1-3 and Comparative Examples 1-2 were used for leaf spraying test on wheat seedlings, and the spraying amount was 100 mL / m 2 The control group was sprayed with the same amount of water, and the retention period of the foliar fertilizer, the degradation rate of the effective component of the foliar fertilizer, the dispersion stability and the photosynthetic efficiency improvement rate were detected. The test results are shown in Table 1.

[0141] The detection of the nutrient retention period comprises the following steps: periodically detecting the residual amount of effective amino acid on the leaf surface after spraying, and recording the time when the residual amount is reduced to 10% of the initial value;

[0142] The detection of the degradation rate of the effective component comprises the following steps: after spraying, irradiating for 7 days under the condition of light intensity ≥10000 lux, and detecting the degradation proportion of the amino acid;

[0143] The detection of the dispersion stability comprises the following steps: after the tested foliar fertilizer is packaged in a sealed package, it is placed for 30 days, and whether the amino acid compound foliar fertilizer system appears stratification, precipitation or nutrient aggregation phenomenon is observed;

[0144] The detection of the photosynthetic efficiency improvement rate comprises the following steps: after spraying for 15 days, the photosynthetic rate of the wheat leaf is detected by using a photosynthetic instrument, and the improvement proportion compared with the control group is calculated.

[0145] Table 1 Performance test results

[0146]

[0147] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, thus, equivalent changes made on the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. An amino acid complex foliar fertilizer, characterized by, By mass fraction, the following components are included: L-alanine 1.8-2.2 parts, L-serine 1.2-1.5 parts, amino acid microspheres 3.5-4.5 parts, citric acid-chitosan modified biochar 8.0-9.0 parts, lanthanum nitrate 0.2-0.3 parts, cerium nitrate 0.2-0.3 parts, Tween 80 0.8-1.2 parts, ethylene glycol 1.8-2.2 parts, and water 73-75 parts; The amino acid microspheres contain 0.9-1.3 parts of L-valine and 0.7-0.9 parts of L-leucine.

2. The amino acid complex foliar fertilizer according to claim 1, characterized in that, The preparation method of the amino acid microspheres comprises the following steps: S1, after sugarcane residue is dried and crushed, it is mixed with sodium hydroxide aqueous solution, stirred and reacted at 85-95°C, filtered, the filtrate is adjusted to pH=2.0-2.5 with hydrochloric acid, and then left to stand at 25-35°C to obtain a lignin precipitate; S2, the lignin precipitate, citric acid, and water are mixed, stirred and reacted at 35-40°C, and then sheared and emulsified at 25-35°C to obtain an alkali lignin-citric acid complex; S3, the alkali lignin-citric acid complex, trehalose, and water are mixed, stirred and reacted at 25-35°C to obtain a coating liquid; S4, L-valine, L-leucine, and water are mixed, stirred and reacted at 35-45°C to obtain a core material mother liquor; S5, the coating liquid and the core material mother liquor are mixed, sheared and emulsified at 25-35°C, then calcium chloride is added, and stirred and reacted at 30-40°C to obtain the amino acid microspheres.

3. The amino acid complex foliar fertilizer of claim 2, wherein, In S1, the mass-to-volume ratio of the sugarcane residue and the sodium hydroxide aqueous solution is 1g:(10-15)mL, and the mass percentage of the sodium hydroxide aqueous solution is 1%-3%; and / or In S2, the mass-to-volume ratio of the lignin precipitate, citric acid, and water is 1g:(0.05-0.15)g:(5-6)mL; and / or In S3, the mass-to-volume ratio of the alkali lignin-citric acid complex, trehalose, and water is 1g:(0.6-0.7)g:(7-8)mL; and / or In S4, the mass-to-volume ratio of L-valine, L-leucine, and water is 1g:(0.7-0.8)g:(7.5-8.5)mL; and / or In S5, the volume ratio of the coating liquid and the core material mother liquor is (2-4):1; and / or In S5, the volume-to-mass ratio of the core material mother liquor and calcium chloride is 1mL:(0.005-0.015)g.

4. The amino acid complex foliar fertilizer of claim 2, wherein, In S1, the stirring speed of the stirring and reacting is 200-500r / min, and the time is 2-4h; and / or In S1, the standing time is 2-4h; and / or In S2, the stirring speed of the stirring and reacting is 400-600r / min, and the time is 0.5-1.5h; and / or In S2, the shearing and emulsifying speed is 18000-22000r / min, and the time is 10-20min; and / or In S2, the shearing and emulsifying speed is 18000-22000r / min, and the time is 10-20min; and / or In S3, the stirring speed is 400 r / min-600 r / min, and the stirring time is 15 min-45 min; and / or In S4, the stirring speed is 400 r / min-600 r / min, and the stirring time is 15 min-45 min; and / or In S5, the shearing emulsification speed is 13000 r / min-17000 r / min, and the shearing emulsification time is 5 min-15 min; and / or In S5, the stirring speed is 400 r / min-600 r / min, and the stirring time is 20 min-40 min.

5. The amino acid complex foliar fertilizer of claim 1, wherein, The preparation method of the citric acid-chitosan modified biochar comprises the following steps: Step 1, corn straw biochar is dried and crushed, and then mixed with phosphoric acid aqueous solution, and stirred at 55-65°C to obtain a preliminary modified biochar; Step 2, the preliminary modified biochar, citric acid, chitosan and water are mixed, and stirred at 45-55°C to obtain the citric acid-chitosan modified biochar.

6. The amino acid complex foliar fertilizer of claim 5, wherein, In step 1, the mass-volume ratio of the corn straw biochar and the phosphoric acid aqueous solution is 1g:(8-12)mL, and the mass percentage of the phosphoric acid aqueous solution is 3%-7%; and / or In step 2, the mass-volume ratio of the preliminary modified biochar, citric acid, chitosan and water is 1g:(0.03-0.05)g:(0.02-0.03)g:(7-9)mL.

7. The amino acid complex foliar fertilizer of claim 5, wherein, In step 1, the stirring speed is 400 r / min-600 r / min, and the stirring time is 3h-5h; and / or In step 2, the stirring speed is 400 r / min-600 r / min, and the stirring time is 0.5h-1.5h.

8. A process for the preparation of the amino acid complex foliar fertilizer according to any one of claims 1 to 7, characterized in that, comprises the following steps: Step one, the amino acid microspheres, the citric acid-chitosan modified biochar and water are mixed, and stirred at 30-40°C to obtain a slow-release mixture; Step two, the slow-release mixture, L-alanine, L-serine, lanthanum nitrate, cerium nitrate, Tween 80 and ethylene glycol are mixed, and stirred at 30-40°C, and then sheared and emulsified at 25-35°C to obtain the amino acid compound foliar fertilizer.

9. The method for preparing the amino acid compound foliar fertilizer according to claim 8, characterized in that, In step one, the stirring speed is 400 r / min-600 r / min, and the stirring time is 15 min-45 min; and / or In step two, the stirring speed is 400 r / min-600 r / min, and the stirring time is 30 min-40 min; and / or In step two, the shearing emulsification speed is 2800 r / min-3200 r / min, and the shearing emulsification time is 15 min-25 min.

10. The application of the amino acid compound foliar fertilizer of any one of claims 1-7 or the amino acid compound foliar fertilizer prepared by the preparation method of claim 8 or 9 in a foliar fertilizer.

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