Preparation process and application of multifunctional slow-release saline-alkali soil conditioner

Abstract

The application relates to the technical field of saline-alkali soil improvement, and particularly discloses a preparation process of a multifunctional slow-release type saline-alkali soil improver and application thereof. The preparation process comprises the following steps: (1) uniformly mixing seaweed acid powder, phosphogypsum powder, carbon powder and water to form wet materials, then placing the wet materials in a sealed container for heating and heat preservation treatment, and obtaining a precursor after the treatment; and (2) placing the precursor at normal temperature for standing, crushing the precursor after the standing, and obtaining the soil improver. The soil improver prepared by the above process can not only more efficiently and quickly fix sodium ions, potassium ions, calcium ions and magnesium ions in the soil, but also can reduce the content of carbonate ions, so that the soil salt content and the soil alkalinity are reduced. In addition, the soil improver can help to relieve the phenomenon of soil alkali and salt return, and reduce the usage amount of the improver in the subsequent soil improvement process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of saline-alkali soil improvement, and particularly relates to a preparation process of a multifunctional slow-release saline-alkali soil improver and application thereof. BACKGROUND

[0002] The saline-alkali land refers to a land type in which excessive salt and alkaline substances in soil lead to land productivity decline and ecological environment deterioration. Since most crops usually have difficulty in surviving in the saline-alkali land, even if they can survive, the yield will be greatly reduced, which seriously affects agricultural production and ecological environment, so it is very important to improve the saline-alkali land. The saline-alkali land has the characteristics of high salt and high alkali mainly because the saline-alkali land contains a large amount of sodium, potassium, calcium, magnesium and carbonates, sulfates and chlorides such as sodium sulfate, potassium sulfate, calcium chloride, which make the soil show high salt, and the alkaline salts such as sodium carbonate and potassium carbonate make the soil show high alkalinity. Since sodium and potassium ions are difficult to be fixed in the soil, a large amount of water washing is needed to remove alkali from the soil, which not only consumes a large amount of water and produces a large amount of wastewater, but also has a huge amount of work. The way of improving the saline-alkali land by plants or microorganisms has a long cycle and slow effect. Therefore, there is an urgent practical need to explore an efficient and long-acting saline-alkali land improvement technology. SUMMARY

[0003] In view of the above problems, the present application provides a preparation process of a multifunctional slow-release saline-alkali soil improver and application thereof. The soil improver can not only more efficiently and quickly fix sodium, potassium, calcium and magnesium ions in the soil, but also reduce the content of carbonate ions, thereby reducing the salt content and alkalinity of the soil. Specifically, the technical scheme of the present application is as follows.

[0004] Firstly, the present application discloses a preparation process of a multifunctional slow-release saline-alkali soil improver, which comprises the following steps:

[0005] (1) uniformly mixing seaweed acid powder, phosphogypsum powder, carbon powder and water to form wet material, and then placing the wet material in a sealed container for heating and heat preservation treatment, and obtaining a precursor after completion.

[0006] (2) placing the precursor at room temperature for standing, and obtaining the soil improver after completion and breaking treatment.

[0007] Further, in step (1), the mass ratio of the seaweed acid powder, the phosphogypsum powder and the carbon powder is 1-2.5 g:4-7 g:2-3 g.

[0008] Further, in step (1), the solid-liquid ratio of the seaweed acid powder, the phosphogypsum powder, the carbon powder and water is 1 g:3-4.2 g. Optionally, the fineness of the carbon powder is 20-40 mesh.

[0009] Further, in step (1), the temperature of the heating and holding is 150-220 DEG C, and the time is 1-3 hours.

[0010] Further, in step (1), the pressure in the closed container is 0.35-0.6 MPa.

[0011] Further, in step (1), the wet material further contains sugarcane molasses. Optionally, the proportion of the sugarcane molasses is 10-14% of the total mass of the alginate powder, the phosphogypsum powder and the carbon powder.

[0012] Further, in step (2), the crushing is performed after standing for 5-7 days, to obtain the soil conditioner.

[0013] Further, in step (2), the particle size of the soil conditioner is 1-5 mm.

[0014] Secondly, the application of the multifunctional slow-release saline-alkali soil conditioner is disclosed: after the application of the conditioner to the saline-alkali soil and stirring, water is sprinkled to wet the soil, and then the soil is left to stand.

[0015] Further, the application amount of the conditioner is 230-350 kg / acre.

[0016] Further, the standing time after the water sprinkling is 7-10 days. Optionally, the water is sprinkled every 2-3 days.

[0017] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0018] The soil conditioner of the present application takes seaweed acid powder, phosphor gypsum powder, carbon powder and sugar cane molasses as raw materials, and after mixing the above raw materials, pre-treatment is carried out under high temperature and high pressure, in the process, the carbon powder is activated by the acid environment provided by the phosphor gypsum, and the adsorption performance of the carbon powder is improved, thereby helping to improve the desalination capacity of the conditioner to the soil. Further, the present application also utilizes the hydration and cementation characteristics of the phosphor gypsum to cement the components together to form a conditioner that can desalt and dealkalize the soil. When the conditioner enters the soil, on the one hand, under the adsorption of the carbon powder, the carbonate, bicarbonate, sodium, potassium, calcium and magnesium ions in the soil enter the conditioner, the phosphor gypsum contains phosphoric acid which is acidic, and after reacting with the carbonate and bicarbonate, it is converted into carbon dioxide and water to be removed, thereby rapidly reducing the alkalinity of the soil. At the same time, it also provides phosphorus elements for the soil, which helps to improve the nutrition of the soil. On the other hand, the seaweed acid reacts with the carbonate and bicarbonate to form sodium alginate and potassium alginate under the alkaline environment of the soil, and at the same time, the carbonate and bicarbonate are converted into carbon dioxide and water. The sodium alginate and potassium alginate crosslink to form gel-like substances under the action of calcium and magnesium ions, and since the substances are insoluble in water, the solidification of sodium, potassium, calcium and magnesium ions is realized at the same time. After the above effects, the salt content in the soil can be rapidly reduced, and since the carbonate and bicarbonate form water-soluble salts with sodium and potassium, which are the main source of high alkalinity of the soil, the removal and solidification of these ions also effectively reduce the alkalinity of the soil. On the other hand, as the soil desalination and dealkalization reduce the alkalinity, the reaction of the seaweed acid gradually stops, and the gel material forms a slow-release structure in the internal gap channel of the conditioner, thereby avoiding excessive consumption of the conditioner. When the soil becomes alkaline again, the reaction of the seaweed acid starts, thereby helping to alleviate the phenomenon of soil alkaline and salty, and reducing the amount of the conditioner used in the subsequent soil improvement process. In addition, the sugar cane molasses not only can reduce the alkalinity of the soil, but also can provide nutrients for the microorganisms in the soil, promote the reproduction of the microorganisms in the soil, reduce the soil compaction, and improve the soil fertility. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. In the following, the embodiments of the present application will be described in detail with reference to the accompanying drawings, in which:

[0020] Figure 1 A sample picture of the wet material prepared for the following Example 1.

[0021] Figure 2 A sample picture of the slow-release type saline-alkali soil conditioner prepared for the following Example 1. DETAILED DESCRIPTION

[0022] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate but not limit the scope of the application. The experimental methods in the following examples, if not otherwise specified, are generally carried out according to the conventional conditions or according to the conditions recommended by the manufacturers.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The reagents or materials used in the present application can be purchased through conventional routes. Unless otherwise specified, the reagents or materials used in the present application are used according to the conventional methods or according to the product instructions.

[0024] In addition, any methods and materials similar or equivalent to those described herein can be used in the present application. The preferred methods and materials described in the present application are only used for demonstration in conjunction with the drawings and specific embodiments of the present application.

[0025] Example 1

[0026] A preparation process of a multifunctional slow-release saline-alkali soil conditioner includes the following steps:

[0027] (1) Mix the sea alginic acid powder, phosphogypsum powder and 40-mesh carbon powder according to the mass ratio of 2g:5g:2.5g, and stir them uniformly to form a mixed powder. Then, add 4 times the mass of the mixed powder of water, and stir them quickly and uniformly to form a wet material (as shown in FIG. 1), and then place the wet material in a reaction container, heat it to 180℃ after being sealed, and keep it for 1.5 hours, wherein the pressure is set to 0.6 MPa, and the precursor is obtained after completion. Figure 1

[0028] (2) Take out the precursor from the reaction container, and let it stand at room temperature for 7 days, and then perform a crushing treatment, and screen out the granular materials with a particle size of 1-3mm, and the soil conditioner is as shown in FIG. 2. Figure 2

[0029] According to the addition amount of 300kg / acre, the soil conditioner prepared in the present example is added to the soil of a certain test saline-alkali land with pH=8.74, and is stirred and wetted. Then, let it stand for 7 days, and wet it once every 2 days during the period. Then, test the pH-a of the improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+ ) therein, calculate the salt content reduction rate / desalination rate a. In addition, after 60 days, the pH-b of the improved soil and the salt content therein are measured again, and the desalination rate b is calculated, and the results are shown in the following table.​​

[0030]

[0031] Example 2

[0032] A preparation process of a multifunctional slow-release saline-alkali soil conditioner, comprising the following steps:

[0033] (1) Alginic acid powder, phosphogypsum powder and 20-mesh carbon powder are mixed in a mass ratio of 1 g:4 g:2 g, and then stirred uniformly to form a mixed powder. Then 10% of the mass of the mixed powder of sugarcane molasses, 3 times the mass of the mixed powder of water are added and stirred uniformly to form a wet material, and then the wet material is placed in a reaction container, sealed and heated to 150℃ for 3 hours, wherein the pressure is set to 0.5 MPa, and the precursor is obtained after completion.

[0034] (2) The precursor is taken out of the reaction container and left to stand at room temperature for 6 days, and then broken up and sieved to obtain granular material with a particle size of 3-5 mm, which is the soil conditioner.

[0035] The soil conditioner prepared in this example is added to a certain test saline-alkali soil (the same as in Example 1) with pH=8.74 at an addition amount of 350 kg / acre, and then stirred and wetted with water. Then left to stand for 10 days, during which water is sprayed every 3 days. Then the pH-a of the improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+ ) are tested, and the salt content reduction rate / desalination rate a is calculated. In addition, the pH-b of the improved soil and the salt content are measured again after 60 days, and the desalination rate b is calculated, and the results are shown in the following table.

[0036]

[0037] Example 3

[0038] A preparation process of a multifunctional slow-release saline-alkali soil conditioner, comprising the following steps:

[0039] (1) Alginic acid powder, phosphogypsum powder and 20-mesh carbon powder are mixed in a mass ratio of 2.5 g:7 g:3 g, and then stirred uniformly to form a mixed powder. Then 14% of the mass of the mixed powder of sugarcane molasses, 4.2 times the mass of the mixed powder of water are added and stirred uniformly to form a wet material, and then the wet material is placed in a reaction container, sealed and heated to 220℃ for 1 hour, wherein the pressure is set to 0.35 MPa, and the precursor is obtained after completion.

[0040] (2) After the precursor is taken out from the reaction container, it is left to stand at normal temperature for 5 days, and then is subjected to crushing treatment, and the granular substance with a particle size of 1-4 mm is sieved, and the soil conditioner is obtained.

[0041] The soil conditioner prepared in this example is added to the test saline-alkali soil (the same as in Example 1) with a pH of 8.74 in an amount of 230 kg / ha, and is uniformly stirred and then wetted with water. Then, it is left to stand for 8 days, and is wetted with water every 3 days during the period. Then, the pH-a of the improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+ ) thereof are measured, and the salt content reduction rate a is calculated. In addition, the pH-b and the salt content of the improved soil are measured again after 60 days, the desalination rate b is calculated, and the results are shown in the following table.

[0042]

[0043] Example 4

[0044] A preparation process of a multifunctional slow-release saline-alkali soil conditioner, comprising the following steps:

[0045] (1) Phosphogypsum powder and 40-mesh carbon powder are mixed in a mass ratio of 5 g:2.5 g, and are uniformly stirred to form a mixed powder. Then, 4 times the mass of the mixed powder of water is added, and is rapidly stirred to form a wet material. Then, the wet material is placed in a reaction container, is sealed, is heated to 180°C, and is kept for 1.5 hours, wherein the pressure is set to 0.6 MPa, and a precursor is obtained.

[0046] (2) After the precursor is taken out from the reaction container, it is left to stand at normal temperature for 7 days, and then is subjected to crushing treatment, and the granular substance with a particle size of 1-3 mm is sieved, and the soil conditioner is obtained.

[0047] The soil conditioner prepared in this example is added to the test saline-alkali soil (the same as in Example 1) in an amount of 300 kg / ha, and is uniformly stirred and then wetted with water. Then, it is left to stand for 7 days, and is wetted with water every 2 days during the period. Then, the pH-a of the improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+, and the salt content in the improved soil is measured again after 60 days, and the desalination rate b is calculated, and the results are shown in the following table.

[0048]

[0049] Example 5

[0050] A preparation process of a multifunctional slow-release saline-alkali soil improver includes the following steps:

[0051] (1) Alginic acid powder and phosphogypsum powder are mixed according to a mass ratio of 2.5g:7g, and then stirred uniformly to form a mixed powder. Then, 14% of the mass of the mixed powder of sugarcane molasses, 4.2 times the mass of the mixed powder of water are added, and then stirred uniformly to form a wet material. Then, the wet material is placed in a reaction container, sealed, heated to 220°C, and kept for 1 hour, wherein the pressure is set to 0.35 MPa, and the precursor is obtained.

[0052] (2) The precursor is taken out of the reaction container and left to stand at room temperature for 5 days, and then broken up for treatment. The granular material with a particle size of 1-4mm is screened out, and the soil improver is obtained.

[0053] The soil improver prepared in this example is added to the same saline-alkali soil in Example 1 according to an addition amount of 300kg / acre, and then stirred uniformly and wetted with water. Then, it is left to stand for 8 days, and wetted with water every 3 days during the period. Then, the pH-a of the improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+ ) are tested, and the salt content reduction rate / desalination rate a is calculated. In addition, the pH-b of the improved soil and the salt content therein are measured again after 60 days, and the desalination rate b is calculated, and the results are shown in the following table.

[0054]

[0055] Example 6

[0056] A preparation process of a multifunctional slow-release saline-alkali soil improver includes the following steps:

[0057] (1) Alginic acid powder, phosphogypsum powder and 20-mesh carbon powder are mixed according to a mass ratio of 1g:4g:2g, and then stirred uniformly to form a mixed powder. Then, 10% of the mass of the mixed powder of sugarcane molasses, 3 times the mass of the mixed powder of water are added, and then stirred uniformly to form a wet material.

[0058] (2) The wet material is left to stand at room temperature for 6 days, and then is subjected to crushing treatment, and the granular substance having a particle size of 3 to 5 mm is sieved out, and the soil conditioner.

[0059] The soil conditioner prepared in this example is added to the same saline-alkali soil as in Example 1 at an addition amount of 300 kg / ha, and is uniformly stirred and then is sprinkled with water to be moistened. Then, it is left to stand for 10 days, and is sprinkled with water to be moistened every 3 days during the period. Then, the pH-a of the obtained improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+ ) thereof are measured, and the salt content reduction rate a is calculated. In addition, the pH-b of the improved soil and the salt content thereof are measured again after 60 days, the desalination rate b is calculated, and the results are shown in the following table.

[0060]

[0061] Example 7

[0062] A preparation process of a multifunctional slow-release saline-alkali soil conditioner, comprising the following steps:

[0063] (1) Sea alginic acid powder, chemically pure gypsum powder (component: CaSO4·2H2O) and carbon powder of 40 mesh are mixed at a mass ratio of 2 g: 5 g: 2.5 g, and are uniformly stirred to form a mixed powder. Then, 4 times the mass of the mixed powder of water is added, and is rapidly stirred to form a wet material. Then, the wet material is placed in a reaction container, is sealed, is heated to 180°C, and is kept for 1.5 hours, wherein the pressure is set to 0.6 MPa, and the precursor is obtained after completion.

[0064] (2) The precursor is taken out from the reaction container, and is left to stand at room temperature for 7 days. Then, it is subjected to crushing treatment, and the granular substance having a particle size of 1 to 3 mm is sieved out, and the soil conditioner.

[0065] The soil conditioner prepared in this example is added to the same saline-alkali soil as in Example 1 at an addition amount of 300 kg / ha, and is uniformly stirred and then is sprinkled with water to be moistened. Then, it is left to stand for 7 days, and is sprinkled with water to be moistened every 2 days during the period. Then, the pH-a of the obtained improved soil and the salt content (CO3 2- , HCO3 - , K + , Na + , Ca 2+ , Mg 2+), and the desalination rate a is calculated. In addition, the pH-b and the salt content in the improved soil are measured again after 60 days, the desalination rate b is calculated, and the results are shown in the following table.

[0066]

[0067] The above description is only preferred embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A preparation process of a multifunctional slow-release saline-alkali soil conditioner, characterized in that: The steps include: (1) uniformly mixing alginate powder, phosphogypsum powder, carbon powder and water to form a wet material, and then placing the wet material in a sealed container for heating and heat preservation treatment to obtain a precursor; (2) allowing the precursor to stand at room temperature, and then crushing the precursor to obtain the soil conditioner; In step (1), the mass ratio of the alginate powder, phosphogypsum powder, and carbon powder is 1-2.5 g: 4-7 g: 2-3 g, and the material-liquid ratio of the total mass of the alginate powder, phosphogypsum powder, and carbon powder to water is 1 g: 3-4.2 g; In step (1), the wet material further contains sugarcane molasses; In step (1), the fineness of the carbon powder is 20-40 mesh; In step (1), the pressure in the sealed container is 0.35~0.6MPa.

2. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the heating and heat preservation temperature is 150-220° C., and the time is 1-3 hours.

3. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, wherein the sugarcane molasses accounts for 10-14% of the total mass of the alginate powder, phosphogypsum powder, and carbon powder.

4. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (2), the crushing is performed after standing for 5 to 7 days to obtain the soil conditioner.

5. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to any one of claims 1 to 4, characterized in that: In step (2), the particle size of the soil conditioner is 1-5 mm.

6. Use of the multifunctional slow-release saline-alkali soil conditioner obtained by the preparation process according to any one of claims 1 to 4, characterized in that: The improver is applied to the saline-alkali soil and stirred evenly, and then sprinkled with water to moisten the soil and allowed to stand.

7. The use according to claim 6, characterized in that The application amount of the improver is 230~350kg / mu.

8. The use according to claim 7, characterized in that The standing time after the watering and wetting is 7 to 10 days.

9. The use according to claim 6, characterized in that Water it every 2 to 3 days.

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