Preparation method of alkali-reducing salt-inhibiting cotton liquid fertilizer

Abstract

The invention relates to the field of fertilizers, in particular to a preparation method of an alkali-reducing salt-inhibiting cotton liquid fertilizer. The fertilizer comprises the following components: 70-100 g / L of potassium nitrate, 10-25 g / L of potassium dihydrogen phosphate, 15-55 g / L of potassium acetate, 10-50 g / L of alginic acid, 30-55 g / L of urea phosphate, 12-36 g / L of medium element substances, 10-30 g / L of trace element substances, 12-46 g / L of fulvic acid, 5-15 g / L of a stabilizer and 6-20 g / L of calcium alginate microspheres loaded with a composite salt inhibitor. According to the special alkali-reducing and salt-inhibiting liquid fertilizer for cotton, provided by the invention, the salt-inhibiting component is loaded by using the calcium alginate gel microspheres which are prepared by a double-emulsion method and are simple in preparation process and controllable in microsphere particle size, and the calcium alginate gel microspheres shrink in an acid environment and swell in an alkaline environment, so that the salt-inhibiting component can be slowly and accurately released around crop rhizosphere.

Description

Technical Field

[0001] The present invention relates to the field of fertilizers, and specifically relates to a preparation method of an alkali-reducing and salt-inhibiting cotton liquid fertilizer. Background Art

[0002] Xinjiang is the largest cotton-producing area in China, with a planting area accounting for more than 80% of the country. The drip irrigation under film technology is convenient for mechanical operation and has the advantages of water and fertilizer conservation, etc. It is a revolution in cotton irrigation methods, replacing traditional irrigation methods such as flood irrigation and furrow irrigation, and opening up a new way for the development of efficient water-saving irrigation technology in Xinjiang.

[0003] Currently, alkali-reducing and salt-controlling products are a hot topic in domestic and foreign research. At present, some products have been formed. However, due to the single product or limited technical regionalization, the products that can be truly promoted and widely applied still cannot meet the demand, or the product cost is high and difficult to be accepted by the market, resulting in the inability to achieve large-scale promotion and application.

[0004] The groundwater in Xinjiang has a high salt content. The long-term application of integrated water and fertilizer irrigation is likely to cause clogging of drip irrigation pipes. The liquid salt inhibitor has a short salt prevention period, frequent feeding, and is not easy to store and transport, and cannot meet the demand for long-term cleaning and salt prevention of integrated water and fertilizer pipelines; the product of urea phosphate is a double salt formed by urea and phosphoric acid under certain conditions. By carrying out coating treatment on it, the dual effects of "slow salt and reduce alkali" can be achieved. Therefore, developing an alkali-reducing and salt-inhibiting liquid fertilizer for Xinjiang cotton is of great significance for effectively alleviating the contradiction between supply and demand of regional water resources, solving the bottleneck problem of improving the quality and efficiency of Xinjiang cotton, accelerating the formation of a green production and quality improvement system for Xinjiang cotton, promoting the quality and efficiency improvement of the Xinjiang cotton industry, enhancing the innovation ability of the cotton industry, and helping the high-quality development of Xinjiang cotton. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a preparation method of an alkali-reducing and salt-inhibiting cotton liquid fertilizer.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] In the first aspect, the present invention provides an alkali-reducing and salt-inhibiting cotton liquid fertilizer, using water as a solvent. Calculated by concentration, the components include:

[0008] Potassium nitrate 70 - 100 g / L, potassium dihydrogen phosphate 10 - 25 g / L, potassium acetate 15 - 55 g / L, alginic acid 10 - 50 g / L, urea phosphate 30 - 55 g / L, medium element substance 12 - 36 g / L, trace element substance 10 - 30 g / L, fulvic acid 12 - 46 g / L, stabilizer 5 - 15 g / L, calcium alginate microspheres carrying a composite salt inhibitor 6 - 20 g / L.

[0009] Preferably, the cotton liquid fertilizer for reducing alkali and suppressing salt uses water as a solvent, and its components by concentration include:

[0010] Potassium nitrate 90 g / L, potassium dihydrogen phosphate 18 g / L, potassium acetate 45 g / L, alginic acid 30 g / L, urea phosphate 45 g / L, medium element substance 24 g / L, trace element substance 15 g / L, fulvic acid 30 g / L, stabilizer 10 g / L, calcium alginate microspheres loaded with composite salt inhibitor 9 g / L.

[0011] Preferably, the brand of the urea phosphate is Xinqili NPK17-44-0.

[0012] Preferably, the medium element substance includes magnesium acetate (AC-Mg) and calcium acetate (AC-Ca), and the mass ratio of magnesium acetate to calcium acetate is 0-1:0-1. More preferably, the mass ratio of magnesium acetate to calcium acetate is 1:1.

[0013] Preferably, the trace element substance includes boric acid (H3BO3), zinc sulfate (ZnSO4), manganese sulfate (MnSO4), copper sulfate (CuSO4), iron acetate (AC-Fe), and the mass ratio of boric acid, zinc sulfate, manganese sulfate, copper sulfate, and iron acetate is 0-1:0-1:0-1:0-1:0-1. More preferably, the mass ratio of boric acid, zinc sulfate, manganese sulfate, copper sulfate, and iron acetate is 1:1:1:1:1.

[0014] Preferably, the purity of the fulvic acid is higher than 90%.

[0015] Preferably, the stabilizer is sodium carboxymethyl cellulose (CMC), with a viscosity of 800-1200 mPa·s and USP grade.

[0016] Preferably, the preparation method of the calcium alginate microspheres loaded with composite salt inhibitor includes:

[0017] S1. Prepare the composite salt inhibitor:

[0018] Weigh polyaldehyde alginate and dissolve it in a mixed solution of dimethyl sulfoxide and deionized water to obtain a polyaldehyde alginate solution; weigh 2-aminoacetamide and dissolve it in N,N-dimethylformamide to obtain a 2-aminoacetamide solution; under nitrogen protection, gradually add the 2-aminoacetamide solution to the polyaldehyde alginate solution, adjust the pH = 4-6 by dripping acetic acid, stir at 40-60 °C for 15-25 h, cool down and pour it into 2 volumes of ethanol, collect the precipitate and dry it to obtain the composite salt inhibitor;

[0019] S2. Configure the solvent:

[0020] Add the composite salt inhibitor into the sodium alginate solution. After fully dissolving, a sodium alginate solution containing the composite salt inhibitor is obtained; weigh sorbitan monooleate and add it to liquid paraffin, stir evenly to obtain a liquid paraffin solution; weigh calcium chloride and add it to deionized water, and dissolve it to obtain a calcium chloride solution.

[0021] S3. Prepare microspheres:

[0022] Under stirring conditions, divide the liquid paraffin solution into two equal parts. Drop the sodium alginate solution containing the composite salt inhibitor into one part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 - 900 rpm for 20 - 30 min to obtain a first mixed solution; drop the calcium chloride solution into the other part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 - 900 rpm for 20 - 30 min to obtain a second mixed solution; mix and crosslink the first mixed solution and the second mixed solution. The crosslinking temperature is 18°C, the stirring speed is 750 - 850 rpm, and the crosslinking time is 4 - 6 h; then centrifuge and separate, wash with absolute ethanol 3 - 4 times first, then wash with water 2 - 3 times, and dry at 35 - 45°C for 10 - 14 h to obtain calcium alginate microspheres loaded with the composite salt inhibitor.

[0023] More preferably, in S1, the mass - volume ratio of polyaldehyde - modified sodium alginate, dimethyl sulfoxide, and deionized water is 1 g:(5 - 10) mL:(10 - 20) mL.

[0024] More preferably, in S1, the mass - volume ratio of 2 - aminoacetamide and N,N - dimethylformamide is 0.7 g:(5 - 15) mL.

[0025] More preferably, in S1, the volume of the 2 - aminoacetamide solution is 1.2 - 1.8 times the volume of the polyaldehyde - modified sodium alginate solution.

[0026] More preferably, in S2, the mass fraction of the sodium alginate solution is 1% - 10%, and the mass - volume ratio of the composite salt inhibitor and the sodium alginate solution is 1 g:(10 - 30) mL.

[0027] More preferably, in S2, sorbitan monooleate is used as a surfactant, with an active ingredient of 99%, a density of 0.986 g / mL (25°C), and a boiling point of 463.43°C.

[0028] More preferably, in S2, the mass - volume ratio of sorbitan monooleate and liquid paraffin is 0.5 g:(20 - 60) mL.

[0029] More preferably, in S2, the mass - volume ratio of calcium chloride and deionized water is 1.1 g:(10 - 30) mL.

[0030] More preferably, in S3, the volume ratio of the sodium alginate solution containing the composite salt inhibitor, the calcium chloride solution and the liquid paraffin solution is 1:1:1.5-2.5.

[0031] Preferably, the preparation method of the polyaldehyde sodium alginate comprises:

[0032] Weigh sodium alginate and disperse it in anhydrous ethanol to obtain a sodium alginate solution; dissolve sodium periodate in deionized water to obtain a sodium periodate solution; gradually add the sodium periodate solution into the sodium alginate aqueous solution, stir for 5-15 hours in a dark environment at room temperature, then drop ethylene glycol to terminate the reaction, then pour into 2 times the volume of ethanol, collect the precipitate and dry it to obtain polyaldehyde sodium alginate.

[0033] More preferably, the mass volume ratio of sodium alginate to anhydrous ethanol is 1 g:(5-10) mL; the mass volume ratio of sodium periodate to deionized water is 1 g:(5-15) mL; and the volume ratio of sodium periodate solution to sodium alginate aqueous solution is 1:1.1-1.3.

[0034] In a second aspect, the present invention provides a method for preparing a liquid fertilizer for cotton with reduced alkali and suppressed salt, comprising the following steps:

[0035] Step 1: Weigh urea phosphate and dissolve it in water, then add potassium nitrate and stir to dissolve to obtain a mixed solution A;

[0036] Step 2, weighing alginic acid and dissolving it in water, then adding the middle element substance, fulvic acid, potassium acetate and potassium dihydrogen phosphate, stirring with a magnetic stirrer, and homogenizing in a homogenizer to obtain a mixed solution B;

[0037] Step 3: Weigh the trace elements separately, mix them and add them into deionized water, stir them thoroughly, and obtain a mixed solution C;

[0038] Step 4: Fully mix the mixed solution A, mixed solution B and mixed solution C, then slowly add the stabilizer, and then add the calcium alginate gel microspheres loaded with the composite salt inhibitor, and homogenize in a homogenizer to obtain a liquid fertilizer specifically for cotton with alkali-reducing and salt-inhibiting properties.

[0039] The beneficial effects of the present invention are:

[0040] 1. The alkali-reducing and salt-inhibiting cotton liquid fertilizer provided by the present invention contains a strong acidic component, urea phosphate, which can significantly reduce the pH value of alkaline soil on the one hand; on the other hand, it can reduce the volatilization loss of ammonium nitrogen in alkaline soil and increase the stability of amide nitrogen. It activates phosphorus and trace elements in the soil, prevents phosphorus from being fixed by elements such as calcium and magnesium, and increases the mobility of phosphorus.

[0041] 2. The special liquid fertilizer for cotton with alkali reduction and salt inhibition provided by the present invention has a composite salt inhibition main component prepared from 2-aminoacetamide and polyaldehyde sodium alginate. Compared with the aminoacetamide (NTA) salt inhibitor, the composite salt inhibitor introduces a Schiff base group and sodium alginate, and can complex more Ca in the salt 2+ , Mg 2+ . At the same time, it inhibits the crystallization and growth of salts, significantly improves the solubility of salts, and reduces salt precipitation. In addition, calcium alginate gel microspheres prepared by the double emulsion method with a simple preparation process and controllable microsphere particle size are used to load the salt inhibition component. It shrinks in an acidic environment and swells in an alkaline environment, and can realize the slow and precise release of the salt inhibition component around the rhizosphere of crops.

[0042] 3. The special liquid fertilizer for cotton with alkali reduction and salt inhibition provided by the invention chelates organic acids such as fulvic acid and potassium acetate with metal ions to isolate the combination of metal ions and phosphate groups, thereby reducing the generation of solid precipitation. At the same time, sodium carboxymethyl cellulose is used as a stabilizer. On the one hand, it can be used as a ligand of the chelating agent, and on the other hand, it can improve the stability and interfacial properties of the liquid fertilizer. Detailed implementation manners

[0043] The technical solutions of the present invention are described below through specific specific examples. It should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combined steps or that other method steps can be inserted between these clearly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Moreover, unless otherwise stated, the numbers of the method steps are only convenient tools for identifying the method steps, rather than limiting the arrangement order of the method steps or the scope in which the present invention can be implemented. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0044] In order to better understand the above technical solutions, the exemplary embodiments of the present invention are described in more detail below. Although the exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0045] The present invention is further described below in conjunction with the following embodiments.

[0046] Example 1

[0047] A kind of liquid fertilizer for cotton with alkali reduction and salt inhibition, using water as a solvent, and calculated by concentration, the components include:

[0048] Potassium nitrate 90g / L, potassium dihydrogen phosphate 18g / L, potassium acetate 45g / L, alginate 30g / L, urea phosphate 45g / L, medium-amount elements (AC-Mg, AC-Ca 12g / L each), trace elements (boric acid, ZnSO4, MnSO4, CuSO4, AC-Fe 3g / L each), purified fulvic acid 30g / L, stabilizer CMC (sodium carboxymethyl cellulose) 10g / L, calcium alginate gel microspheres loaded with composite salt inhibitor 9g / L.

[0049] The preparation method of the above-mentioned liquid fertilizer comprises:

[0050] Step 1: Weigh urea phosphate and dissolve it in water, then add potassium nitrate and stir to dissolve to obtain a mixed solution A;

[0051] Step 2, weighing alginic acid and dissolving it in water, then adding AC-Mg, AC-Ca, fulvic acid, potassium acetate and potassium dihydrogen phosphate, stirring with a magnetic stir (30° C., 10 min), placing in a homogenizer, and homogenizing for 15 min to obtain a mixed solution B;

[0052] Step 3: Weigh boric acid, ZnSO4, MnSO4, CuSO4, and AC-Fe respectively, add them to deionized water and stir them thoroughly to obtain a mixed solution C;

[0053] Step 4: Fully mix the mixed solution A prepared in step 1, the mixed solution B prepared in step 2, and the mixed solution C prepared in step 3, then slowly add the CMC stabilizer, and then add the calcium alginate gel microspheres loaded with the composite salt inhibitor, and homogenize in a homogenizer for 25 minutes to obtain a liquid fertilizer specifically for cotton with alkali reduction and salt inhibition.

[0054] The preparation method of calcium alginate microspheres loaded with a composite salt inhibitor comprises:

[0055] (1) Preparation of polyaldehyde sodium alginate:

[0056] Weigh 1 g of sodium alginate (weight average molecular weight 10 kDa) and disperse it in 8 mL of anhydrous ethanol to obtain a sodium alginate solution; dissolve 1 g of sodium periodate in 10 mL of deionized water to obtain a sodium periodate solution; gradually add 1 volume of the sodium periodate solution to 1.2 volumes of the sodium alginate aqueous solution, stir for 10 hours under light shielding at room temperature, then drop ethylene glycol to terminate the reaction, then pour into 2 volumes of ethanol, collect the precipitate and dry it to obtain polyaldehyde sodium alginate;

[0057] (2) Preparation of composite salt inhibitor:

[0058] Weigh 1 g of polyaldehyde alginate and dissolve it in a mixed solution of 8 mL of dimethyl sulfoxide and 15 mL of deionized water to obtain a polyaldehyde alginate solution; weigh 0.7 g of 2-aminoacetamide and dissolve it in 10 mL of N,N-dimethylformamide to obtain a 2-aminoacetamide solution; under nitrogen protection, gradually add 1.5 times the volume of the 2-aminoacetamide solution to 1 times the volume of the polyaldehyde alginate solution, stir at 50 °C for 20 h, cool down and pour it into 2 times the volume of ethanol, collect the precipitate and dry it to obtain a composite salt inhibitor;

[0059] (3) Prepare the solvent:

[0060] Add 1 g of the composite salt inhibitor to 20 mL of a 5 wt% alginate solution, and after fully dissolving, obtain an alginate solution containing the composite salt inhibitor; weigh 0.5 g of sorbitan monooleate and add it to 40 mL of liquid paraffin, stir well to obtain a liquid paraffin solution; weigh 1.1 g of calcium chloride and add it to 20 mL of deionized water, and after dissolving, obtain a calcium chloride solution;

[0061] (4) Prepare the microspheres:

[0062] Under stirring conditions, divide the liquid paraffin solution into two equal parts. Drop the alginate solution containing the composite salt inhibitor into one part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 850 rpm for 25 min to obtain a first mixed solution; drop the calcium chloride solution into the other part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 850 rpm for 25 min to obtain a second mixed solution; mix and crosslink the first mixed solution and the second mixed solution, the crosslinking temperature is 18 °C, the stirring speed is 800 rpm, and the crosslinking time is 5 h; then carry out centrifugal separation, wash 4 times with absolute ethanol first, then wash 3 times with water, and dry at 40 °C for 12 h to obtain calcium alginate microspheres loaded with the composite salt inhibitor.

[0063] Example 2

[0064] A cotton liquid fertilizer for reducing alkali and inhibiting salt, using water as the solvent, and calculated by concentration, the components include:

[0065] Potassium nitrate 70 g / L, potassium dihydrogen phosphate 10 g / L, potassium acetate 15 g / L, alginic acid 10 g / L, urea phosphate 30 g / L, medium element substances (AC-Mg, AC-Ca 6 g / L each), trace element substances (boric acid, ZnSO4, MnSO4, CuSO4, AC-Fe 2 g / L each), purified fulvic acid 12 g / L, stabilizer CMC (sodium carboxymethylcellulose) 5 g / L, calcium alginate gel microspheres loaded with the composite salt inhibitor 6 g / L. Among them, the preparation of the calcium alginate gel microspheres loaded with the composite salt inhibitor is the same as in Example 1.

[0066] The preparation method of the above liquid fertilizer includes:

[0067] Step 1: Weigh urea phosphate and dissolve it in water, then add potassium nitrate and stir to dissolve to obtain a mixed solution A;

[0068] Step 2, weighing alginic acid and dissolving it in water, then adding AC-Mg, AC-Ca, fulvic acid, potassium acetate and potassium dihydrogen phosphate, stirring with a magnetic stir (28° C., 10 min), placing in a homogenizer, and homogenizing for 15 min to obtain a mixed solution B;

[0069] Step 3: Weigh boric acid, ZnSO4, MnSO4, CuSO4, and AC-Fe respectively, add them to deionized water and stir them thoroughly to obtain a mixed solution C;

[0070] Step 4: Fully mix the mixed solution A prepared in step 1, the mixed solution B prepared in step 2, and the mixed solution C prepared in step 3, then slowly add the CMC stabilizer, and then add the calcium alginate gel microspheres loaded with the composite salt inhibitor, and homogenize in a homogenizer for 25 minutes to obtain a liquid fertilizer specifically for cotton with alkali reduction and salt inhibition.

[0071] Example 3

[0072] A liquid fertilizer for reducing alkali and inhibiting salt in cotton, using water as solvent, and calculated by concentration, the ingredients include:

[0073] 100g / L potassium nitrate, 25g / L potassium dihydrogen phosphate, 55g / L potassium acetate, 50g / L alginic acid, 55g / L urea phosphate, medium element substances (AC-Mg, AC-Ca 18g / L each), trace element substances (boric acid, ZnSO4, MnSO4, CuSO4, AC-Fe 6g / L each), 30g / L purified fulvic acid, 15g / L stabilizer CMC (sodium carboxymethyl cellulose), 20g / L calcium alginate gel microspheres loaded with composite salt inhibitor. The preparation of calcium alginate gel microspheres loaded with composite salt inhibitor is the same as that in Example 1.

[0074] The preparation method of the above-mentioned liquid fertilizer comprises:

[0075] Step 1: Weigh urea phosphate and dissolve it in water, then add potassium nitrate and stir to dissolve to obtain a mixed solution A;

[0076] Step 2, weighing alginic acid and dissolving it in water, then adding AC-Mg, AC-Ca, fulvic acid, potassium acetate and potassium dihydrogen phosphate, stirring with a magnetic stirrer (30° C., 15 min), placing in a homogenizer, and homogenizing for 18 min to obtain a mixed solution B;

[0077] Step 3: Weigh boric acid, ZnSO4, MnSO4, CuSO4, and AC-Fe respectively, add them to deionized water and stir them thoroughly to obtain a mixed solution C;

[0078] Step 4: Thoroughly mix the mixed solution A prepared in Step 1, the mixed solution B prepared in Step 2, and the mixed solution C prepared in Step 3. Then slowly add the CMC stabilizer, and further add the calcium alginate gel microspheres loaded with the composite salt inhibitor. Homogenize in a homogenizer for 25 min to obtain the special liquid fertilizer for reducing alkali and inhibiting salt in cotton.

[0079] Example 4

[0080] A liquid fertilizer for reducing alkali and inhibiting salt in cotton, which is different from Example 1 in that the preparation method of the calcium alginate gel microspheres loaded with the composite salt inhibitor is different.

[0081] Among them, the preparation method of the calcium alginate microspheres loaded with the composite salt inhibitor includes:

[0082] (1) Prepare polyaldehyde sodium alginate:

[0083] Weigh 1 g of sodium alginate (weight average molecular weight 10 kDa) and disperse it in 5 mL of absolute ethanol to obtain a sodium alginate solution; dissolve 1 g of sodium periodate in 5 mL of deionized water to obtain a sodium periodate solution; gradually add 1 volume of the sodium periodate solution to 1.1 volumes of the sodium alginate aqueous solution, stir in the dark at room temperature for 5 h, then add ethylene glycol to terminate the reaction, and then pour it into 2 volumes of ethanol. Collect the precipitate and dry it to obtain polyaldehyde sodium alginate;

[0084] (2) Prepare the composite salt inhibitor:

[0085] Weigh 1 g of polyaldehyde sodium alginate and dissolve it in a mixed solution of 5 mL of dimethyl sulfoxide and 10 mL of deionized water to obtain a polyaldehyde sodium alginate solution; weigh 0.7 g of 2-aminoacetamide and dissolve it in 5 mL of N,N-dimethylformamide to obtain a 2-aminoacetamide solution; under nitrogen protection, gradually add 1.2 volumes of the 2-aminoacetamide solution to 1 volume of the polyaldehyde sodium alginate solution, stir at 40 °C for 15 h, cool down and pour it into 2 volumes of ethanol. Collect the precipitate and dry it to obtain the composite salt inhibitor;

[0086] (3) Prepare the solvent:

[0087] Add 1 g of the composite salt inhibitor to 10 mL of a 1 wt% sodium alginate solution, and fully dissolve it to obtain a sodium alginate solution containing the composite salt inhibitor; weigh 0.5 g of sorbitan monooleate and add it to 20 mL of liquid paraffin, stir well to obtain a liquid paraffin solution; weigh 1.1 g of calcium chloride and add it to 10 mL of deionized water, dissolve it to obtain a calcium chloride solution;

[0088] (4) Prepare the microspheres:

[0089] Under stirring conditions, divide the liquid paraffin solution into two equal parts. Drop the sodium alginate solution containing the composite salt inhibitor into one part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 rpm for 20 min to obtain the first mixed solution; drop the calcium chloride solution into the other part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 rpm for 20 min to obtain the second mixed solution; mix and crosslink the first mixed solution and the second mixed solution, the crosslinking temperature is 18 °C, the stirring speed is 750 rpm, and the crosslinking time is 4 h; then perform centrifugal separation, wash 3 times with absolute ethanol first, then wash 2 times with water, and dry at 35 °C for 10 h to obtain calcium alginate microspheres loaded with the composite salt inhibitor.

[0090] Example 5

[0091] Among them, the preparation method of the calcium alginate microspheres loaded with the composite salt inhibitor includes:

[0092] (1) Prepare polyaldehyde sodium alginate:

[0093] Weigh 1 g of sodium alginate (weight average molecular weight 10 kDa) and disperse it in 10 mL of absolute ethanol to obtain a sodium alginate solution; dissolve 1 g of sodium periodate in 15 mL of deionized water to obtain a sodium periodate solution; gradually add 1 volume of the sodium periodate solution to 1.3 volumes of the sodium alginate aqueous solution, stir in the dark at room temperature for 15 h, then dropwise add ethylene glycol to terminate the reaction, and then pour it into 2 volumes of ethanol, collect the precipitate and dry it to obtain polyaldehyde sodium alginate;

[0094] (2) Prepare the composite salt inhibitor:

[0095] Weigh 1 g of polyaldehyde sodium alginate and dissolve it in a mixed solution of 10 mL of dimethyl sulfoxide and 20 mL of deionized water to obtain a polyaldehyde sodium alginate solution; weigh 0.7 g of 2-aminoacetamide and dissolve it in 15 mL of N,N-dimethylformamide to obtain a 2-aminoacetamide solution; under nitrogen protection, gradually add 1.8 volumes of the 2-aminoacetamide solution to 1 volume of the polyaldehyde sodium alginate solution, stir at 60 °C for 25 h, cool down and pour it into 2 volumes of ethanol, collect the precipitate and dry it to obtain the composite salt inhibitor;

[0096] (3) Configure the solvent:

[0097] Add 1 g of the composite salt inhibitor to 30 mL of a 10 wt% sodium alginate solution, and fully dissolve it to obtain a sodium alginate solution containing the composite salt inhibitor; weigh 0.5 g of sorbitan monooleate and add it to 60 mL of liquid paraffin, stir evenly to obtain a liquid paraffin solution; weigh 1.1 g of calcium chloride and add it to 30 mL of deionized water, dissolve it to obtain a calcium chloride solution;

[0098] (4) Prepare microspheres:

[0099] Under stirring conditions, divide the liquid paraffin solution into two equal parts. Drop the sodium alginate solution containing the composite salt inhibitor into one part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 900 rpm for 30 min to obtain the first mixed solution; drop the calcium chloride solution into the other part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 900 rpm for 30 min to obtain the second mixed solution; mix and crosslink the first mixed solution and the second mixed solution, the crosslinking temperature is 18 °C, the stirring speed is 850 rpm, and the crosslinking time is 6 h; then carry out centrifugal separation, wash 4 times with absolute ethanol first, then wash 3 times with water, and dry at 45 °C for 14 h to obtain calcium alginate microspheres loaded with the composite salt inhibitor.

[0100] Comparative Example 1

[0101] A preparation method of a special liquid fertilizer for alkali-resistant and salt-inhibiting cotton, which is different from Example 1 in that the calcium alginate microspheres loaded with the composite salt inhibitor are replaced by aminoacetamide.

[0102] Comparative Example 2

[0103] A preparation method of a special liquid fertilizer for alkali-resistant and salt-inhibiting cotton, which is different from Example 1 in that the calcium alginate microspheres loaded with the composite salt inhibitor are replaced by an inhibitor prepared by compounding aminoacetamide: ferrous salt: sodium alginate in a mass ratio of 1:0.1.

[0104] Comparative Example 3

[0105] A preparation method of a special liquid fertilizer for alkali-resistant and salt-inhibiting cotton, which is different from Example 1 in that in step 5, the calcium alginate microspheres loaded with the composite salt inhibitor are replaced by an inhibitor prepared by compounding the composite salt inhibitor and sodium alginate in a mass ratio of 1:0.1; wherein, the preparation method of the composite salt inhibitor is the same as that in Example 1.

[0106] Comparative Example 4

[0107] A preparation method of a special liquid fertilizer for alkali-resistant and salt-inhibiting cotton, which is different from Example 1 in that in step 5, the calcium alginate microspheres loaded with the composite salt inhibitor are replaced by calcium alginate microspheres loaded with aminoacetamide.

[0108] The preparation method of calcium alginate microspheres loaded with aminoacetamide includes:

[0109] (1) Prepare the solvent:

[0110] Add 1 g of aminoacetamide to 10 mL of 1 wt% sodium alginate solution, and after fully dissolving, obtain a sodium alginate solution containing aminoacetamide; weigh 0.5 g of sorbitan monooleate and add it to 20 mL of liquid paraffin, and stir evenly to obtain a liquid paraffin solution; weigh 1.1 g of calcium chloride and add it to 10 mL of deionized water, and dissolve it to obtain a calcium chloride solution;

[0111] (2) Preparation of microspheres:

[0112] Under stirring conditions, divide the liquid paraffin solution into two equal parts. Drop the sodium alginate solution containing aminoacetamide into one part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 rpm for 20 min to obtain the first mixed solution; drop the calcium chloride solution into the other part of the liquid paraffin solution, and continuously stir and emulsify at a speed of 800 rpm for 20 min to obtain the second mixed solution; mix and crosslink the first mixed solution and the second mixed solution, the crosslinking temperature is 18 °C, the stirring speed is 750 rpm, and the crosslinking time is 4 h; then perform centrifugal separation, wash 3 times with absolute ethanol first, then wash 2 times with water, and dry at 35 °C for 10 h to obtain calcium alginate microspheres loaded with aminoacetamide.

[0113] Experimental example

[0114] Through field experiments, the effects of the fertilizers prepared in the examples and comparative examples on the physical and chemical properties of saline-alkali soil and cotton growth in the main cotton-producing areas of Xinjiang were determined. The cotton variety is "Zhongmian 113", the test site is selected in Changji City, Xinjiang, the area of each test group is 1 mu, and the physical and chemical properties of the soil are: pH = 8.29, salt content 3.42 g / kg, organic matter 10.24 g / kg, EC 1.37 mS / cm, CO3 2- 0 g / kg, HCO3 - 0.6676 g / kg, Ca 2+ 0.4178 g / kg, Mg 2+ 0.0949 g / kg, Na + 0.5934.

[0115] Cotton was sown on April 20, 2024, and the emergence water was dripped on April 25. The water was dripped 12 times during the whole growth period, and the water dripping amount was about 4000 m 3 / hm 2 , except for the emergence water, the fertilizers in the examples and comparative examples were added to the fertilization tank and applied with water each time when dripping water. Other field measures such as sowing, irrigation, and weeding were the same. The cotton was harvested on October 2.

[0116] The emergence rate was measured 10 days after sowing.

[0117] The soil salt content and pH were measured by the conductivity method with a soil-water ratio of 1:5; EC was measured by the conductivity method with a soil-water ratio of 1:2.5; water-soluble CO3 2- and HCO3 - were measured by the double indicator neutralization titration method; Ca 2+ and Mg 2+ were measured by the EDTA titration method; Na + was measured by the flame photometry method.

[0118] Total alkalinity = [CO32- +[HCO3 - ;

[0119]

[0120] Among them, [CO3 2- is the concentration of CO3 2- , [HCO3 - is the concentration of HCO3 - ; [Na + is the concentration of Na + ; [Mg 2+ is the concentration of Mg 2+ ; [Ca 2+ is the concentration of Ca 2+ .

[0121] The yield is calculated by selecting a certain area in the test area to count the number of cotton plants and bolls in the early stage of harvest, and randomly picking 100 open bolls from the upper, middle and lower parts of the cotton plants in each plot for sun drying and weighing. The cotton yield is calculated based on the measured area, the number of bolls per plant, the total number of bolls and the boll weight.

[0122] The test results are shown in Table 1

[0123] Table 1 Effects of different treatments on the physical and chemical properties of cotton soil

[0124]

[0125] Table 2 Effects of different treatments on the emergence rate and yield of cotton

[0126] Group Emergence rate (%) <![CDATA[Yield (kg / hm 2 )]]> Example 1 89 6325.80 Comparative Example 1 71 5976.92 Comparative Example 2 74 6131.79 Comparative Example 3 79 6232.18 Comparative Example 4 82 6261.29

[0127] It can be seen from the above experimental results that the liquid fertilizer prepared in Example 1 of the present invention has a certain improvement effect on the pH, EC value, salt content, total alkalinity and sodium adsorption ratio of saline-alkali soil, and also has a better growth-promoting effect on Xinjiang cotton growing in saline-alkali soil, with a significant increase in the emergence rate and yield.

[0128] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0129] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A liquid fertilizer for cotton with reduced alkali and suppressed salt, characterized in that: Taking water as solvent, the ingredients include: Potassium nitrate 70-100g / L, potassium dihydrogen phosphate 10-25g / L, potassium acetate 15-55g / L, alginic acid 10-50g / L, urea phosphate 30-55g / L, medium element substances 12-36g / L, trace element substances 10-30g / L, fulvic acid 12-46g / L, stabilizer 5-15g / L, calcium alginate microspheres loaded with composite salt inhibitor 6-20g / L.

2. A kind of alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 1, characterized in that, The intermediate element substances include magnesium acetate and calcium acetate, and the mass ratio of magnesium acetate to calcium acetate is 0-1:0-1; the trace element substances include boric acid, zinc sulfate, manganese sulfate, copper sulfate, and ferric acetate, and the mass ratio of boric acid, zinc sulfate, manganese sulfate, copper sulfate, and ferric acetate is 0-1:0-1:0-1:0-1:0-1.

3. A kind of alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 1, characterized in that, The preparation method of the calcium alginate microspheres loaded with a composite salt inhibitor comprises: S1. Weigh polyaldehyde sodium alginate and dissolve it in a mixture of dimethyl sulfoxide and deionized water to obtain a polyaldehyde sodium alginate solution; weigh 2-aminoacetamide and dissolve it in N,N-dimethylformamide to obtain a 2-aminoacetamide solution; add the 2-aminoacetamide solution to the polyaldehyde sodium alginate solution, adjust the pH to 4-6, stir at 40-60° C. for 15-25 hours, precipitate and dry to obtain a composite salt inhibitor; S2, adding the composite salt inhibitor to the sodium alginate solution, dissolving it to obtain a sodium alginate solution containing the composite salt inhibitor; weighing sorbitan monooleate and adding it to liquid paraffin, stirring it to obtain a liquid paraffin solution; weighing calcium chloride and adding it to deionized water, dissolving it to obtain a calcium chloride solution; S3. Under stirring, the liquid paraffin solution is divided into two parts, a sodium alginate solution containing a composite salt inhibitor is added dropwise to one part to obtain a first mixed solution, and a calcium chloride solution is added dropwise to the other part to obtain a second mixed solution; the first mixed solution and the second mixed solution are mixed and cross-linked; then centrifuged, washed and dried to obtain calcium alginate microspheres loaded with the composite salt inhibitor.

4. A alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 3, characterized in that, In the S1, the mass volume ratio of polyaldehyde sodium alginate, dimethyl sulfoxide and deionized water is 1g:(5-10)mL:(10-20)mL.

5. A kind of alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 3, characterized in that, In S1, the mass volume ratio of 2-aminoacetamide to N,N-dimethylformamide is 0.7 g:(5-15) mL; the volume of the 2-aminoacetamide solution is 1.2-1.8 times the volume of the polyaldehyde sodium alginate solution.

6. A alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 3, characterized in that, In S2, the mass fraction of the sodium alginate solution is 1%-10%, the mass volume ratio of the composite salt inhibitor to the sodium alginate solution is 1g:(10-30)mL; the mass volume ratio of sorbitan monooleate to liquid paraffin is 0.5g:(20-60)mL; and the mass volume ratio of calcium chloride to deionized water is 1.1g:(10-30)mL.

7. A alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 3, characterized in that, In S3, the volume ratio of the sodium alginate solution containing the composite salt inhibitor, the calcium chloride solution and the liquid paraffin solution is 1:1:1.5-2.

5.

8. A alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 3, characterized in that, The preparation method of the polyaldehyde sodium alginate comprises: Weigh sodium alginate and disperse it in anhydrous ethanol to obtain a sodium alginate solution; dissolve sodium periodate in deionized water to obtain a sodium periodate solution; gradually add the sodium periodate solution into the sodium alginate aqueous solution, stir for 5-15 hours in a dark environment at room temperature, then drop ethylene glycol to terminate the reaction, then pour into 2 times the volume of ethanol, collect the precipitate and dry it to obtain polyaldehyde sodium alginate.

9. A alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 7, characterized in that, The mass volume ratio of the sodium alginate to anhydrous ethanol is 1 g:(5-10) mL; the mass volume ratio of sodium periodate to deionized water is 1 g:(5-15) mL; and the volume ratio of the sodium periodate solution to the sodium alginate aqueous solution is 1:1.1-1.

3.

10. A method for preparing the alkali-reducing and salt-inhibiting cotton liquid fertilizer according to claim 1, characterized in that: The following steps are involved: Step 1: Weigh urea phosphate and dissolve it in water, then add potassium nitrate and stir to dissolve to obtain a mixed solution A; Step 2, weighing alginic acid and dissolving it in water, then adding the middle element substance, fulvic acid, potassium acetate and potassium dihydrogen phosphate, stirring with a magnetic stirrer, and homogenizing in a homogenizer to obtain a mixed solution B; Step 3: Weigh the trace elements separately, mix them and add them into deionized water, stir them thoroughly, and obtain a mixed solution C; Step 4: Fully mix the mixed solution A, mixed solution B and mixed solution C, then slowly add the stabilizer, and then add the calcium alginate gel microspheres loaded with the composite salt inhibitor, and homogenize in a homogenizer to obtain a liquid fertilizer specifically for cotton with alkali-reducing and salt-inhibiting properties.

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