A load-modified soda saline soil conditioner and its preparation method

Abstract

This invention relates to the field of soil pollution remediation technology, specifically to a loaded modified soda-based soil conditioner and its preparation method. The conditioner comprises the following components by weight: 35-45 parts acidified zeolite, 15-30 parts fulvic acid-modified calcium alginate microspheres, 10-30 parts aluminum sulfate, 5-20 parts ferrous sulfate, 5-10 parts solid organic fertilizer, 2-5 parts stearic acid, 0.1-0.2 parts citric acid, and 5-15 parts deionized water. This invention features a reasonable formulation and a simple preparation process, combining desalination and salt suppression, pH regulation, and organic matter enhancement functions. By loading fulvic acid-modified calcium alginate microspheres onto acidified zeolite, adsorption and slow release of fulvic acid and calcium alginate can be achieved, ensuring its continued effectiveness during long-term use.

Description

Technical Field

[0001] This invention relates to the field of soil pollution remediation technology, specifically to a loaded modified soda saline soil conditioner and its preparation method. Background Technology

[0002] Soda saline soil refers to saline soil containing a high amount of alkaline substances such as sodium carbonate and sodium bicarbonate. It is a type of alkalized soil, also known as soda saline-alkali soil. The soil colloids in soda saline soil carry a large number of negative charges. These negative charges adsorb sodium ions from the soil solution, creating a sodium-saturated state. Due to the hydrolysis of sodium ions, the soil colloid particles disperse, the soil structure is damaged, becoming compacted and hardened, with extremely poor aeration and permeability, thus affecting the growth and development of plant roots.

[0003] Chinese invention with publication number CN110055084B discloses a soda saline-alkali paddy field soil conditioner and its preparation method. The invention uses zeolite as a blocking agent. The pores and pore structure of zeolite itself are easily occupied or blocked by some impurity ions, resulting in relatively few available adsorption sites and an unsatisfactory adsorption capacity. This is not conducive to a full chemical reaction and adsorption with pollutants or blocking substances in the soil.

[0004] Chinese invention application CN119528640A discloses a functional slow-release fertilizer for regulating and improving the productivity of saline soil and its preparation method. The formula of this invention application includes gypsum, zeolite powder and fertilizer matrix. The fertilizer matrix includes a core material, the surface of which is coated with sodium ethylenediaminetetraacetate and sodium alginate from the inside out. The inherent high hygroscopic and swelling characteristics of alginate fertilizers may bring the following technical challenges: 1. Storage stability: In case of improper humidity control or exposure after opening, the product is prone to clumping and hardening, which significantly reduces the convenience of application; 2. Agronomic performance: After being applied to the soil, excessive water absorption and the resulting aggregates will damage the soil structure, leading to decreased aeration and obstructed water penetration, which in turn affects crop root development; 3. Storage management: Because the alginate component is sensitive to humid and hot environments, the product must be strictly sealed and stored under dry, cool, and ventilated conditions. Otherwise, the degradation of the effective ingredients will be accelerated, which will not only shorten the product shelf life, but also significantly increase the storage management cost. Summary of the Invention

[0005] The purpose of this invention is to provide a load-modified soda saline soil conditioner and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a load-modified soda saline soil conditioner, wherein the conditioner comprises the following components by weight: 35-45 parts of acidified zeolite, 15-30 parts of fulvic acid-modified calcium alginate microspheres, 10-30 parts of aluminum sulfate, 5-20 parts of ferrous sulfate, 5-10 parts of solid organic fertilizer, 2-5 parts of stearic acid, 0.1-0.2 parts of citric acid, and 5-15 parts of deionized water;

[0007] The preparation steps of the acidified zeolite are as follows: first, the clinoptilolite is acidified with 0.5 mol / L hydrochloric acid solution for 2 hours, and then activated by calcination at 350°C;

[0008] The preparation method of the fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stirring continuously for 60-120min, then weigh 5-10ml of silicone oil and add it to the sodium alginate solution, stirring continuously. S4: Using a peristaltic pump, slowly drip the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 90-120 minutes, remove the gel microspheres and place them in a 0.02-0.05 mol / L calcium chloride solution for 30-60 minutes. S5: Remove the gel microspheres and ultrasonically wash them with deionized water for 10-15 minutes until the washing water is neutral, to obtain the fulvic acid modified calcium alginate microspheres.

[0009] Optionally, the preparation steps of the acidified zeolite are as follows: first, the clinoptilolite is acidified with 0.5 mol / L hydrochloric acid solution for 2 hours, and then activated by calcination at 350°C.

[0010] Optionally, the fulvic acid is mineral-derived fulvic acid, and a 10% aqueous solution of the fulvic acid has a pH of 2.5 to 3.0 and a heavy metal content of <20 ppm.

[0011] Optionally, the solid organic fertilizer is one or a combination of more than one of wheat straw powder, corn straw powder, peat moss, bagasse, distiller's grains, mushroom compost, fish bone meal, oyster shell powder, seaweed fertilizer, coconut coir, and earthworm castings.

[0012] Optionally, the silicone oil is Dow Corning PMX-0156 series silicone oil, and the viscosity of the silicone oil at 20°C is 50–120 cSt.

[0013] On the other hand, the present invention also provides the following technical solution: a method for preparing a load-modified soda saline soil conditioner, comprising the following steps:

[0014] S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 300-600 r / min for 10-20 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 300-600 r / min for 30-60 min to obtain mixture A.

[0015] S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 200-400 r / min for 20-30 min to obtain mixture B;

[0016] S3, Mixing 3: First, heat mixture B to 60-75℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 100-300 r / min for 15-30 min to obtain mixture C. Adjust the moisture content of mixture C to 10%-25%.

[0017] S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, thus obtaining granules;

[0018] S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture from the granules until the moisture content of the granules is reduced to 5% to 10%. The granules are then cooled to room temperature to obtain the modifier.

[0019] Optionally, the particle size is 3-5 mm.

[0020] In addition, the present invention provides the following technical solution: a method for using a load-modified soda saline soil conditioner, wherein after the autumn crop harvest and before the soil freezes, or before spring tillage, the conditioner is mechanically and evenly applied to the ground surface according to the actual dosage, and then a rotary tiller is used to perform rotary tillage to mix the conditioner into the soil layer of ≤20cm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention has a reasonable formula and a simple preparation process. It has the functions of desalination and salt inhibition, pH regulation and organic matter enhancement. By loading fulvic acid onto acidified zeolite to modify calcium alginate microspheres, it can achieve adsorption and slow release of fulvic acid and calcium alginate, ensuring its continuous effectiveness in long-term use.

[0023] 2. The raw materials such as acidified zeolite, aluminum sulfate, and ferrous sulfate in the formulation of this invention are all common chemical products or natural minerals, widely available and relatively inexpensive. By loading fulvic acid-modified calcium alginate microspheres onto acidified zeolite, not only is the dispersibility and stability of the microspheres in the soil improved, but their binding ability with soil particles is also enhanced, preventing them from being lost due to wind or water erosion during application. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: The present invention provides a load-modified soda saline soil conditioner, which comprises the following components by weight: 35 parts acidified zeolite, 15 parts humic acid modified calcium alginate microspheres, 10 parts aluminum sulfate, 5 parts ferrous sulfate, 5 parts solid organic fertilizer, 2 parts stearic acid, 0.1 parts citric acid, and 5 parts deionized water.

[0026] The preparation method of fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stir continuously for 60min, then weigh 5ml of silicone oil and add it to the sodium alginate solution. S4: Slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution using a peristaltic pump, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 90 minutes, remove the gel microspheres and place them in a 0.02 mol / L calcium chloride solution for 30 minutes. S5: Remove the gel microspheres and ultrasonically wash them with deionized water for 10 minutes until the washing water is neutral, to obtain fulvic acid modified calcium alginate microspheres.

[0027] The preparation method of the above-mentioned modifier includes the following steps:

[0028] S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 300 r / min for 10 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 300 r / min for 30 min to obtain mixture A.

[0029] S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 200 r / min for 20 min to obtain mixture B;

[0030] S3, Mixing 3: First, heat mixture B to 60℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 100r / min for 15min to obtain mixture C. Adjust the moisture content of mixture C to 10%.

[0031] S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, resulting in particles with a diameter of 3 mm.

[0032] S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture from the granules until the moisture content of the granules is reduced to 5%. The granules are then cooled to room temperature to obtain the modifier.

[0033] Example 2: The present invention provides a load-modified soda saline soil conditioner, which comprises the following components by weight: 38 parts acidified zeolite, 20 parts fulvic acid modified calcium alginate microspheres, 20 parts aluminum sulfate, 10 parts ferrous sulfate, 7 parts solid organic fertilizer, 3 parts stearic acid, 0.1 parts citric acid, and 8 parts deionized water.

[0034] The preparation method of fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stir continuously for 80min, then weigh 6ml of silicone oil and add it to the sodium alginate solution. S4: Stir continuously for 40 minutes to obtain a mixed emulsion; S5: Use a peristaltic pump to slowly drip the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 100 minutes, remove the gel microspheres and place them in a 0.04 mol / L calcium chloride solution for 40 minutes; S6: Remove the gel microspheres and ultrasonically wash them with deionized water for 12 minutes until the washing water is neutral to obtain fulvic acid modified calcium alginate microspheres.

[0035] The preparation method of the above-mentioned modifier includes the following steps:

[0036] S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 400 r / min for 14 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 400 r / min for 40 min to obtain mixture A.

[0037] S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 300 r / min for 25 min to obtain mixture B;

[0038] S3, Mixing 3: First, heat mixture B to 65℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 180r / min for 20min to obtain mixture C. Adjust the moisture content of mixture C to 15%.

[0039] S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, resulting in particles with a diameter of 4 mm.

[0040] S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture until the moisture content of the granules is reduced to 6%. The granules are then cooled to room temperature to obtain the modifier.

[0041] Example 3: The present invention provides a load-modified soda saline soil conditioner, which comprises the following components by weight: 42 parts acidified zeolite, 25 parts humic acid modified calcium alginate microspheres, 25 parts aluminum sulfate, 15 parts ferrous sulfate, 9 parts solid organic fertilizer, 4 parts stearic acid, 0.2 parts citric acid, and 12 parts deionized water.

[0042] The preparation method of fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stir continuously for 100min, then weigh 8ml of silicone oil and add it to the sodium alginate solution. S4: Slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution using a peristaltic pump, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 110 min, remove the gel microspheres and place them in a 0.03 mol / L calcium chloride solution for 50 min. S5: Remove the gel microspheres and ultrasonically wash them with deionized water for 14 min until the washing water is neutral, to obtain fulvic acid modified calcium alginate microspheres.

[0043] The preparation method of the above-mentioned modifier includes the following steps:

[0044] S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 500 r / min for 18 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 500 r / min for 50 min to obtain mixture A.

[0045] S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 350 r / min for 28 min to obtain mixture B;

[0046] S3, Mixing 3: First, heat mixture B to 72℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 250r / min for 25min to obtain mixture C. Adjust the moisture content of mixture C to 20%.

[0047] S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, resulting in particles with a diameter of 4 mm.

[0048] S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture from the granules until the moisture content of the granules is reduced to 8%. The granules are then cooled to room temperature to obtain the modifier.

[0049] Example 4: The present invention provides a load-modified soda saline soil conditioner, which comprises the following components by weight: 45 parts acidified zeolite, 30 parts humic acid modified calcium alginate microspheres, 30 parts aluminum sulfate, 20 parts ferrous sulfate, 10 parts solid organic fertilizer, 5 parts stearic acid, 0.2 parts citric acid, and 5 parts deionized water.

[0050] The preparation method of fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stir continuously for 120min, then weigh 10ml of silicone oil and add it to the sodium alginate solution. S4: Slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution using a peristaltic pump, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 120 min, remove the gel microspheres and place them in a 0.05 mol / L calcium chloride solution for 60 min. S5: Remove the gel microspheres and ultrasonically wash them with deionized water for 15 min until the washing water is neutral, to obtain fulvic acid modified calcium alginate microspheres.

[0051] The preparation method of the above-mentioned modifier includes the following steps:

[0052] S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 600 r / min for 20 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 600 r / min for 60 min to obtain mixture A.

[0053] S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 400 r / min for 30 min to obtain mixture B;

[0054] S3, Mixing 3: First, heat mixture B to 75℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 300r / min for 30min to obtain mixture C. Adjust the moisture content of mixture C to 25%.

[0055] S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, resulting in particles with a diameter of 5 mm.

[0056] S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture from the granules until the moisture content of the granules is reduced to 10%. The granules are then cooled to room temperature to obtain the modifier.

[0057] In Examples 1-4, the acidified zeolite was hydrochloric acid-acid-acidified clinoptilolite, with an average particle size of 140 mesh and a specific surface area of ​​122-355 m². 2 / g. The preparation steps of acidified zeolite are as follows: first, the clinoptilolite is acidified with 0.5 mol / L hydrochloric acid solution for 2 hours, and then activated by calcination at 350℃. Fulvic acid is mineral-derived fulvic acid, and the pH of a 10% aqueous solution of fulvic acid is 2.5-3.0, with a heavy metal content of <20 ppm. Solid organic fertilizer is a combination of wheat straw powder, corn straw powder, peat moss, bagasse, distiller's grains, mushroom residue, fish bone meal, oyster shell powder, seaweed fertilizer, coconut coir, and earthworm castings. Silicone oil is Dow Corning PMX-0156 series silicone oil, and the viscosity of the silicone oil at 20℃ is 50-120 cSt.

[0058] It should be noted that acidified zeolite has excellent adsorption properties, capable of adsorbing harmful substances in the soil, such as heavy metal ions and pesticide residues, while also adsorbing and slowly releasing nutrients, thus improving the soil's ability to retain nutrients. Furthermore, the porous structure of acidified zeolite can improve soil aeration and promote plant root growth.

[0059] Fulvic acid can optimize soil aggregate structure, increase the content of aggregates ≥25mm and organic matter content, thereby improving soil water retention and fertilizer retention. Calcium alginate can interact with organic matter in the soil to form more colloidal substances, increasing the soil's water retention and fertilizer retention capacity, thus improving soil fertility.

[0060] The first function of silicone oil is to adjust the viscosity and surface tension of the sodium alginate solution. After mixing the sodium alginate solution with fulvic acid, an appropriate amount of silicone oil emulsion is added and thoroughly stirred before proceeding with the subsequent dropwise cross-linking step. This allows the silicone oil to coat the surface of the microspheres, forming a hydrophobic film that reduces the contact between the microspheres and moisture in the air, thereby lowering the likelihood of them absorbing water and hardening. The second function of silicone oil is to coat the surface of the microspheres and delay the reaction of the sodium alginate and fulvic acid mixture on the Ca2+ surface. 2+ The cross-linking effect under the action of [the agent / organism] results in a more uniform and stable gel structure, for the following reasons:

[0061] 1. Prevent excessive local cross-linking: If the reaction is too fast, Ca 2+ It will rapidly combine with multiple carboxyl groups of sodium alginate molecules, leading to excessive local cross-linking and the formation of a tight gel region, while other regions have not yet fully reacted. This uneven cross-linking will cause stress concentration points inside the microspheres, reducing the overall strength and stability of the microspheres.

[0062] 2. Promotes uniform diffusion: The slow reaction allows Ca to... 2+ Sufficient time was allowed for uniform diffusion in the mixture of sodium alginate and fulvic acid, Ca 2+ It can gradually penetrate into all parts of the mixture and undergo a uniform cross-linking reaction with sodium alginate molecules to form a uniform gel network structure, thereby improving the uniformity and stability of the microspheres.

[0063] 3. Reducing pore defects: During the slow cross-linking reaction, the mixture of sodium alginate and fulvic acid can gradually adjust its own structure, making the formed gel surface more dense, reducing surface pores and defects. The dense surface layer can improve the mechanical strength and stability of the microspheres, preventing the microspheres from breaking or deforming prematurely during subsequent use.

[0064] 4. Avoid fulvic acid aggregation: If the reaction is too fast, fulvic acid may aggregate in local areas, forming an uneven distribution and affecting the performance of microspheres. A slow reaction helps to inhibit the aggregation of fulvic acid, allowing it to be better dispersed in the gel network, thereby enhancing the adsorption and sustained-release properties of the microspheres.

[0065] 5. Sufficient Interaction: The slow reaction process provides ample time for the interaction between fulvic acid and sodium alginate. Functional groups in the fulvic acid molecule (such as carboxyl and hydroxyl groups) can interact with sodium alginate molecules and Ca... 2+ The full combination of these components forms a more stable composite structure. This full interaction helps the fulvic acid to be evenly dispersed in the gel network, thus exerting its modifying effect on the properties of the microspheres.

[0066] Comparative Example 1

[0067] This is essentially the same as Example 4, except that the fulvic acid-modified calcium alginate microspheres are replaced with calcium alginate gel microspheres, which are produced by Xi'an Ruixi Biotechnology.

[0068] The present invention also discloses a method for using the above-mentioned soil conditioner. After the autumn crop harvest and before the soil freezes, or before spring tillage, the conditioner is mechanically and evenly applied to the ground surface according to the actual dosage. Then, a rotary tiller is used to perform rotary tillage to mix the conditioner into the soil layer of ≤20cm.

[0069] Experimental Example 1

[0070] Experimental content: Following the application method of the soil conditioner, after crop harvest in September 2023, the soil conditioners prepared in Examples 1 to 4 were applied to four adjacent soda saline land plots at Shuntai Farm in Sheyang, Yancheng. Soil samples were taken in mid-October 2023, with 16 samples taken from each soda saline land plot. The average salt content, pH and organic matter content were statistically analyzed and calculated, and the data are recorded in Table 1.

[0071] Table 1

[0072]

[0073] As shown in Table 1, the improvers prepared in Examples 1 to 4 have the effects of desalination and salt suppression, pH regulation and organic matter enhancement on soda saline land. Among them, the improver prepared in Example 4 has the best performance and is worth promoting.

[0074] Experimental Example 2

[0075] Experimental content: The moisture content of the modifiers prepared in Example 4 and Comparative Example 1 was tested using the drying method. In an environment with a temperature of 25±1℃ and a relative humidity of 75±5%, another batch of modifiers prepared in Example 4 and Comparative Example 1 were taken and stored in woven bags. After 30 days of storage, the moisture content was tested again using the drying method, and the data were recorded in Table 1.

[0076] Table 2

[0077]

[0078] As shown in Table 2, the change in moisture content before and after storage in Example 4 is much smaller than that in Comparative Example 1. Therefore, the modifier prepared in Example 4 has the advantage of moisture stability and can be packaged and stored in ordinary PE bags, which is simple to store.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A load-modified soda-saline soil conditioner, characterized in that: The improver comprises the following components by weight: 35-45 parts acidified zeolite, 15-30 parts fulvic acid modified calcium alginate microspheres, 10-30 parts aluminum sulfate, 5-20 parts ferrous sulfate, 5-10 parts solid organic fertilizer, 2-5 parts stearic acid, 0.1-0.2 parts citric acid, and 5-15 parts deionized water. The preparation steps of the acidified zeolite are as follows: first, the clinoptilolite is acidified with 0.5 mol / L hydrochloric acid solution for 2 hours, and then activated by calcination at 350°C; The preparation method of the fulvic acid modified calcium alginate microspheres includes the following steps: S1: Weigh 0.1g of EDTA-2Na and dissolve it in 100mL of deionized water to obtain an EDTA-2Na solution; S2: Weigh 3g of sodium alginate powder and slowly add it to the EDTA-2Na solution while stirring to obtain a sodium alginate solution; S3: First weigh 2g of fulvic acid and add it to the sodium alginate solution, stirring continuously for 60-120min, then weigh 5-10ml of silicone oil and add it to the sodium alginate solution, stirring continuously. S4: Using a peristaltic pump, slowly drip the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of mixed emulsion forms a gel microsphere in the calcium chloride solution. After standing for 90-120 minutes, remove the gel microspheres and place them in a 0.02-0.05 mol / L calcium chloride solution for 30-60 minutes. S5: Remove the gel microspheres and ultrasonically wash them with deionized water for 10-15 minutes until the washing water is neutral, to obtain the fulvic acid modified calcium alginate microspheres.

2. The load-modified soda-saline soil conditioner according to claim 1, characterized in that: The acidified zeolite is hydrochloric acid-acid-treated clinoptilolite, with an average particle size of 140 mesh and a specific surface area of ​​122–355 m². 2 / g.

3. The load-modified soda-saline soil conditioner according to claim 1, characterized in that: The fulvic acid is mineral-derived fulvic acid, and a 10% aqueous solution of the fulvic acid has a pH of 2.5 to 3.0 and a heavy metal content of <20 ppm.

4. The load-modified soda-saline soil conditioner according to claim 1, characterized in that: The solid organic fertilizer is one or a combination of more than one of the following: wheat straw powder, corn straw powder, peat moss, bagasse, distiller's grains, mushroom compost, fish bone meal, oyster shell powder, seaweed fertilizer, coconut coir, and earthworm castings.

5. The load-modified soda-saline soil conditioner according to claim 1, characterized in that: The silicone oil is Dow Corning PMX-0156 series silicone oil, and the viscosity of the silicone oil at 20°C is 50-120 cSt.

6. The method for preparing the load-modified soda-saline soil conditioner according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1, Mixture 1: First, add acidified zeolite to deionized water and stir continuously at a stirring speed of 300-600 r / min for 10-20 min. Then, add fulvic acid modified calcium alginate microspheres and stir continuously at a stirring speed of 300-600 r / min for 30-60 min to obtain mixture A. S2, Mixture 2: First, add aluminum sulfate and ferrous sulfate to mixture A in sequence, then add citric acid to mixture A, and stir continuously at a stirring speed of 200-400 r / min for 20-30 min to obtain mixture B; S3, Mixing 3: First, heat mixture B to 60-75℃, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 100-300 r / min for 15-30 min to obtain mixture C. Adjust the moisture content of mixture C to 10%-25%. S4. Granulation: The mixture C is fed into a granulator and extruded to granulate, thus obtaining granules; S5. Drying: The granules are fed into a rotary flash dryer to remove excess moisture from the granules until the moisture content of the granules is reduced to 5% to 10%. The granules are then cooled to room temperature to obtain the modifier.

7. The preparation method of a load-modified soda saline soil conditioner according to claim 6, characterized in that: The particle size is 3-5 mm.

8. The method of using the load-modified soda saline soil conditioner according to any one of claims 1 to 5, characterized in that: After the autumn crop harvest and before the soil freezes, or before spring tillage, the soil conditioner should be mechanically and evenly applied to the surface according to the actual dosage, and then a rotary tiller should be used to perform rotary tillage to mix the soil conditioner into the soil layer of ≤20cm.

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