Load modified soda saline soil modifier and preparation method thereof

Abstract

The invention relates to the technical field of soil pollution treatment, in particular to a load modified soda saline soil modifier and a preparation method thereof.The modifier is prepared from, 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 part of citric acid and 5-15 parts of deionized water. According to the present invention, the formula is reasonable, the preparation process is simple, the functions of desalination, salt inhibition, pH regulation and organic matter improvement are provided, the fulvic acid and the calcium alginate can be adsorbed and slowly released by acidifying the zeolite-loaded fulvic acid modified calcium alginate microspheres, and the continuous effectiveness of the fulvic acid and the calcium alginate in the long-term use process is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of soil pollution control, in particular to a loaded modified soda saline soil improver and a preparation method thereof. Background Art

[0002] Soda saline soil refers to saline soil containing high levels of alkaline substances such as sodium carbonate and sodium bicarbonate. This type of soil is alkaline and is also known as soda saline-alkali soil. The soil colloids in soda saline soil carry a large negative charge, which attracts sodium ions in the soil solution, creating a sodium-saturated state. The hydrolysis of sodium ions causes the soil colloid particles to disperse, disrupting the soil structure and making it compact and hardened. This reduces aeration and water permeability, hindering the growth and development of plant roots.

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

[0004] The Chinese invention application with publication number CN119528640A discloses a functional slow-release fertilizer and a preparation method for regulating the increase in saline soil production capacity. The formula of the invention application includes gypsum, zeolite powder and a fertilizer matrix. The fertilizer matrix includes a core material, and the surface of the core material is coated with sodium ethylenediaminetetraacetic acid and sodium alginate from the inside to the outside. The inherent high hygroscopic expansion properties of alginate fertilizers may bring the following technical challenges: 1. Storage stability: In the case of improper humidity control or unsealed exposure, it is easy to cause the product to agglomerate and harden, significantly reducing the convenience of application; 2. Agronomic performance: After application to the soil, excessive water absorption forms agglomerates that destroy the soil structure, resulting in decreased air permeability and obstructed water penetration, thereby affecting the development of crop roots; 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 it will accelerate the degradation of the effective ingredients, which will not only shorten the shelf life of the product, but also significantly increase the storage management cost. Summary of the Invention

[0005] The object of the present invention is to provide a loaded modified soda saline soil improver and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, on the one hand, the present invention provides the following technical solution: a loaded modified soda saline soil conditioner, the conditioner comprising 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; The preparation method of fulvic acid-modified calcium alginate microspheres comprises the following steps: S1: weighing 0.1 g of EDTA-2Na and dissolving it in 100 mL of deionized water to obtain an EDTA-2Na solution; S2: weighing 3 g of sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2 g of fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes, then weighing 5 to 10 ml of silicone oil and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes, and then weighing 5 to 10 ml of silicone oil and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes. Stir for 30 to 60 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 90 to 120 minutes, the gel microspheres are taken out and placed in a 0.02 to 0.05 mol / L calcium chloride solution for 30 to 60 minutes; S5: taking out the gel microspheres and ultrasonically washing them with deionized water for 10 to 15 minutes until the washing water is neutral, thereby obtaining the fulvic acid-modified calcium alginate microspheres.

[0007] Optionally, the acidified zeolite is hydrochloric acid-acidified clinoptilolite, the average particle size of the acidified zeolite is 140 mesh, and the specific surface area of the acidified zeolite is 122 to 355 m 2 / g.

[0008] Optionally, the preparation steps of the acidified zeolite are: firstly acidifying the clinoptilolite with a 0.5 mol / L hydrochloric acid solution for 2 h, and then calcining and activating the zeolite at 350° C.

[0009] Optionally, the fulvic acid is mineral-derived fulvic acid, the pH of a 10% aqueous solution of the fulvic acid is 2.5-3.0, and the heavy metal content is <20 ppm.

[0010] Optionally, the solid organic fertilizer is one or a combination of more than one of wheat straw powder, corn straw powder, peat, bagasse, distiller's grains, mushroom bran, fish bone powder, oyster shell powder, seaweed fertilizer, coconut bran, and earthworm castings.

[0011] Optionally, the silicone oil is Dow Corning PMX-0156 series silicone oil, and the viscosity of the silicone oil at 20° C. is 50 to 120 cSt.

[0012] On the other hand, the present invention also provides the following technical solution: a method for preparing a loaded modified soda saline soil conditioner, comprising the following steps: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 300-600 r / min for 10-20 min, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 300-600 r / min for 30-60 min to obtain a mixture A; S2. Mixing 2: First, aluminum sulfate and ferrous sulfate are added to mixture A in sequence, and then citric acid is added to mixture A. The mixture is stirred continuously at a stirring speed of 200 to 400 r / min for 20 to 30 minutes to obtain mixture B. S3. Mixing 3: First, heat mixture B to 60-75° C., 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, and adjust the moisture content of mixture C to 10%-25%; S4, granulation: feeding the mixture C into a granulator, extruding and granulating to obtain granules; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 5% to 10%, and then cooled to room temperature to obtain the improver.

[0013] Optionally, the particle size of the particles is 3 to 5 mm.

[0014] In addition, the present invention also provides the following technical solution: a method for using a loaded modified soda saline soil conditioner, after the autumn crop is harvested and before the soil is frozen, or before the land is prepared in spring, the conditioner is first mechanically and evenly applied to the surface according to the actual amount, and then a rotary tiller is used to perform rotary tillage operations to mix the conditioner into a soil layer ≤20 cm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention has a reasonable formula and a simple preparation process. It combines the functions of desalination and salt suppression, pH control, and organic matter enhancement. By loading fulvic acid-modified calcium alginate microspheres on acidified zeolite, it can achieve adsorption and sustained release of fulvic acid and calcium alginate, ensuring its continued effectiveness during long-term use. 2. The raw materials such as acidified zeolite, aluminum sulfate, and ferrous sulfate in the formula of the present invention are all common chemical products or natural minerals with a wide range of sources and relatively low prices. By loading the fulvic acid-modified calcium alginate microspheres on the acidified zeolite, this not only improves the dispersibility and stability of the microspheres in the soil, but also enhances their ability to bind to soil particles, thereby preventing them from being lost due to wind erosion or water erosion during application. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] Example 1: The present invention provides a loaded modified soda saline soil conditioner, which comprises the following components by weight: 35 parts of acidified zeolite, 15 parts of fulvic acid modified calcium alginate microspheres, 10 parts of aluminum sulfate, 5 parts of ferrous sulfate, 5 parts of solid organic fertilizer, 2 parts of stearic acid, 0.1 parts of citric acid, and 5 parts of deionized water.

[0018] The preparation method of fulvic acid-modified calcium alginate microspheres comprises the following steps: S1: weighing 0.1 g of EDTA-2Na and dissolving it in 100 mL of deionized water to obtain an EDTA-2Na solution; S2: weighing 3 g of sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2 g of fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 60 minutes, and then weighing 5 ml of silicone oil and adding it to the sodium alginate acid solution. liquid, and continued stirring for 30 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 90 minutes, the gel microspheres are taken out and placed in a 0.02 mol / L calcium chloride solution for 30 minutes; S5: taking out the gel microspheres, and ultrasonically washing them with deionized water for 10 minutes until the washing water becomes neutral, to obtain fulvic acid-modified calcium alginate microspheres.

[0019] The preparation method of the above-mentioned improver comprises the following steps: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 300 r / min for 10 min, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 300 r / min for 30 min to obtain a mixture A; S2, mixing 2: first, aluminum sulfate and ferrous sulfate were added to mixture A in sequence, and then citric acid was added to mixture A, and the mixture was stirred continuously at a stirring speed of 200 r / min for 20 min to obtain mixture B; S3. Mixing 3: First, heat mixture B to 60° C., then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 100 r / min for 15 min to obtain mixture C. The moisture content of mixture C is adjusted to 10%; S4, granulation: the mixture C is fed into a granulator and extruded to obtain granules with a particle size of 3 mm; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 5%, and then cooled to room temperature to obtain an improver.

[0020] Example 2: The present invention provides a loaded modified soda saline soil conditioner, which comprises the following components by weight: 38 parts of acidified zeolite, 20 parts of fulvic acid modified calcium alginate microspheres, 20 parts of aluminum sulfate, 10 parts of ferrous sulfate, 7 parts of solid organic fertilizer, 3 parts of stearic acid, 0.1 parts of citric acid, and 8 parts of deionized water.

[0021] The preparation method of fulvic acid-modified calcium alginate microspheres includes the following steps: S1: weighing 0.1g EDTA-2Na and dissolving it in 100mL deionized water to obtain EDTA-2Na solution; S2: weighing 3g sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2g fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 80min, and then weighing 6ml silicone oil and adding it to the sodium alginate acid solution. and continuously stirred for 40 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 100 minutes, the gel microspheres are taken out and placed in a 0.04 mol / L calcium chloride solution for 40 minutes; S5: taking out the gel microspheres and ultrasonically washing them with deionized water for 12 minutes until the washing water becomes neutral to obtain fulvic acid-modified calcium alginate microspheres.

[0022] The preparation method of the above-mentioned improver comprises the following steps: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 400 r / min for 14 minutes, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 400 r / min for 40 minutes to obtain a mixture A; S2, mixing 2: first, aluminum sulfate and ferrous sulfate were added to mixture A in sequence, and then citric acid was added to mixture A, and the mixture was stirred continuously at a stirring speed of 300 r / min for 25 min to obtain mixture B; S3, mixing three: first heat mixture B to 65°C, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 180 r / min for 20 min to obtain mixture C, and adjust the moisture content of mixture C to 15%; S4, granulation: the mixture C is fed into a granulator and extruded to obtain granules with a particle size of 4 mm; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 6%, and then cooled to room temperature to obtain an improver.

[0023] Example 3: The present invention provides a loaded modified soda saline soil conditioner, which comprises the following components by weight: 42 parts of acidified zeolite, 25 parts of fulvic acid modified calcium alginate microspheres, 25 parts of aluminum sulfate, 15 parts of ferrous sulfate, 9 parts of solid organic fertilizer, 4 parts of stearic acid, 0.2 parts of citric acid, and 12 parts of deionized water.

[0024] The preparation method of fulvic acid-modified calcium alginate microspheres comprises the following steps: S1: weighing 0.1 g of EDTA-2Na and dissolving it in 100 mL of deionized water to obtain an EDTA-2Na solution; S2: weighing 3 g of sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2 g of fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 100 minutes, and then weighing 8 ml of silicone oil and adding it to the sodium alginate acid solution. liquid, and continued stirring for 50 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 110 minutes, the gel microspheres are taken out and placed in a 0.03 mol / L calcium chloride solution for 50 minutes; S5: taking out the gel microspheres, and ultrasonically washing them with deionized water for 14 minutes until the washing water becomes neutral, to obtain fulvic acid-modified calcium alginate microspheres.

[0025] The preparation method of the above-mentioned improver comprises the following steps: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 500 r / min for 18 minutes, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 500 r / min for 50 minutes to obtain a mixture A; S2, mixing 2: first, aluminum sulfate and ferrous sulfate were added to mixture A in sequence, and then citric acid was added to mixture A, and the mixture was stirred continuously at a stirring speed of 350 r / min for 28 min to obtain mixture B; S3. Mixing 3: First, heat mixture B to 72° C., then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 250 r / min for 25 min to obtain mixture C. The moisture content of mixture C is adjusted to 20%; S4, granulation: the mixture C is fed into a granulator and extruded to obtain granules with a particle size of 4 mm; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 8%, and then cooled to room temperature to obtain the improver.

[0026] Example 4: The present invention provides a loaded modified soda saline soil conditioner, which comprises the following components by weight: 45 parts of acidified zeolite, 30 parts of fulvic acid modified calcium alginate microspheres, 30 parts of aluminum sulfate, 20 parts of ferrous sulfate, 10 parts of solid organic fertilizer, 5 parts of stearic acid, 0.2 parts of citric acid, and 5 parts of deionized water.

[0027] The preparation method of fulvic acid-modified calcium alginate microspheres comprises the following steps: S1: weighing 0.1 g of EDTA-2Na and dissolving it in 100 mL of deionized water to obtain an EDTA-2Na solution; S2: weighing 3 g of sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2 g of fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 120 minutes, and then weighing 10 ml of silicone oil and adding it to the sodium alginate acid solution. liquid, and continued stirring for 60 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 120 minutes, the gel microspheres are taken out and placed in a 0.05 mol / L calcium chloride solution for 60 minutes; S5: taking out the gel microspheres, and ultrasonically washing them with deionized water for 15 minutes until the washing water becomes neutral, to obtain fulvic acid-modified calcium alginate microspheres.

[0028] The preparation method of the above-mentioned improver comprises the following steps: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 600 r / min for 20 min, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 600 r / min for 60 min to obtain a mixture A; S2, mixing 2: first, aluminum sulfate and ferrous sulfate were added to mixture A in sequence, and then citric acid was added to mixture A, and stirring was continued at a stirring speed of 400 r / min for 30 min to obtain mixture B; S3, mixing three: first heat mixture B to 75°C, then add solid organic fertilizer and stearic acid to mixture B in sequence, and stir continuously at a stirring speed of 300 r / min for 30 min to obtain mixture C, and adjust the moisture content of mixture C to 25%; S4, granulation: the mixture C is fed into a granulator and extruded to obtain granules with a particle size of 5 mm; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 10%, and then cooled to room temperature to obtain the improver.

[0029] In Examples 1 to 4, the acidified zeolite is clinoptilolite acidified with hydrochloric acid, the average particle size of the acidified zeolite is 140 mesh, and the specific surface area of the acidified zeolite is 122 to 355 m 2 / g. The acidified zeolite was prepared by acidifying the clinoptilolite with a 0.5 mol / L hydrochloric acid solution for 2 hours, followed by calcination at 350°C for activation. The fulvic acid was derived from a mineral source; a 10% aqueous solution had a pH of 2.5-3.0 and a heavy metal content of <20 ppm. The solid organic fertilizer was a combination of wheat straw powder, corn straw powder, peat, bagasse, distiller's grains, mushroom waste, fish bone meal, oyster shell powder, seaweed fertilizer, coconut coir, and earthworm manure. The silicone oil was Dow Corning PMX-0156 series silicone oil, with a viscosity of 50-120 cSt at 20°C.

[0030] It should be noted that acidified zeolite has excellent adsorption properties, capable of absorbing harmful substances in the soil, such as heavy metal ions and pesticide residues. It can also absorb and slowly release nutrients, improving the soil's ability to retain nutrients. In addition, the porous structure of acidified zeolite can improve soil permeability and promote the growth of plant roots.

[0031] Fulvic acid can optimize soil aggregate structure, increasing the content of aggregates ≥25mm and organic matter, thereby improving soil water and fertilizer retention. Calcium alginate can interact with organic matter in the soil to form more colloidal substances, increasing the soil's water and fertilizer retention capacity, thereby improving soil fertility.

[0032] The first function of silicone oil is to adjust the viscosity and surface tension of the sodium alginate solution. After the sodium alginate solution and fulvic acid are mixed, an appropriate amount of silicone oil emulsion is added and thoroughly stirred. The subsequent dropwise crosslinking step allows the silicone oil to coat the surface of the microspheres, forming a hydrophobic film on the surface. This reduces the microspheres' contact with moisture in the air, thereby reducing their likelihood of absorbing water and hardening. The second function of silicone oil is to coat the microspheres' surface and delay the crosslinking of the sodium alginate and fulvic acid mixture under the action of Ca²⁺, thereby achieving a more uniform and stable gel structure. The reasons for this are as follows: 1. Prevent local excessive cross-linking: If the reaction is too fast, Ca²⁺ will quickly combine with multiple carboxyl groups of the sodium alginate molecules, resulting in local excessive cross-linking and forming a dense gel area, while other areas 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; 2. Promote uniform diffusion: The slow reaction allows Ca²⁺ enough time to diffuse evenly in the mixture of sodium alginate and fulvic acid. Ca²⁺ can gradually penetrate into all parts of the mixture and undergo uniform cross-linking reaction with sodium alginate molecules to form a uniform gel network structure, thereby improving the uniformity and stability of the microspheres. 3. Reduce 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 denser, reducing surface pores and defects. The dense surface layer can improve the mechanical strength and stability of the microspheres, preventing the microspheres from prematurely breaking or deforming during subsequent use; 4. Avoid fulvic acid aggregation: If the reaction is too fast, fulvic acid may aggregate in local areas, forming an uneven distribution, affecting the performance of the microspheres. Slow reaction helps to inhibit the aggregation of fulvic acid, making it better dispersed in the gel network, enhancing the adsorption performance and sustained release performance of the microspheres; 5. Sufficient interaction: The slow reaction process provides sufficient time for the interaction between fulvic acid and sodium alginate. The functional groups in the fulvic acid molecules (such as carboxyl, hydroxyl, etc.) can fully combine with the sodium alginate molecules and Ca²⁺ to form a more stable composite structure. This sufficient interaction helps the fulvic acid to be evenly dispersed in the gel network and exert its effect on modifying the performance of the microspheres.

[0033] Comparative Example 1 The method is basically the same as Example 4, with the only difference being that the fulvic acid-modified calcium alginate microspheres are replaced with calcium alginate gel microspheres, which are produced by Xi'an Ruixi Biological.

[0034] The present invention also discloses a method for using the above-mentioned improver. After the crops are harvested in autumn and before the soil is frozen, or before the land is prepared in spring, the improver is first mechanically and evenly applied to the ground surface according to the actual amount, and then a rotary tiller is used to perform rotary tillage operations to mix the improver into a soil layer ≤20 cm.

[0035] Test Example 1 Test content: According to the method for using the modifier, after the crop was harvested in September 2023, the modifiers prepared in Examples 1 to 4 were used on four adjacent soda saline lands in Shuntai Farm, Sheyang, Yancheng, respectively. Soil sampling was carried out in mid-October 2023, and 16 samples were taken from each soda saline land. The average salt content, pH and organic matter content were counted and calculated, and the data were recorded in Table 1.

[0036] Table 1

[0037] As shown in Table 1, the improvers prepared in Examples 1 to 4 have the effects of desalination, salt inhibition, pH control and organic matter improvement on soda saline land. Among them, the improver prepared in Example 4 performs the best and is worthy of promotion and use.

[0038] Test Example 2 Test content: The moisture content of the improver prepared in Example 4 and Comparative Example 1 was detected by the drying method. Under the environment of temperature 25±1°C and relative humidity 75±5%, the improver prepared in Example 4 and Comparative Example 1 of the same batch was taken and stored in woven bags respectively. After storage for 30 days, the moisture content was detected again by the drying method, and the data were recorded in Table 1.

[0039] Table 2

[0040] As shown in Table 2, the change in moisture content of Example 4 before and after storage is much smaller than that of Comparative Example 1. Therefore, the improver 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.

[0041] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A loaded modified soda saline soil conditioner, characterized by: The improver 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; The preparation method of fulvic acid-modified calcium alginate microspheres comprises the following steps: S1: weighing 0.1 g of EDTA-2Na and dissolving it in 100 mL of deionized water to obtain an EDTA-2Na solution; S2: weighing 3 g of sodium alginate powder and slowly adding it to the EDTA-2Na solution while stirring to obtain a sodium alginate acid solution; S3: first weighing 2 g of fulvic acid and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes, then weighing 5 to 10 ml of silicone oil and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes, and then weighing 5 to 10 ml of silicone oil and adding it to the sodium alginate acid solution, stirring continuously for 60 to 120 minutes. Stir for 30 to 60 minutes to obtain a mixed emulsion; S4: using a peristaltic pump to slowly drop the mixed emulsion into a 0.15 mol / L calcium chloride solution, so that each drop of the mixed emulsion forms gel microspheres in the calcium chloride solution. After standing for 90 to 120 minutes, the gel microspheres are taken out and placed in a 0.02 to 0.05 mol / L calcium chloride solution for 30 to 60 minutes; S5: taking out the gel microspheres and ultrasonically washing them with deionized water for 10 to 15 minutes until the washing water is neutral, thereby obtaining the fulvic acid-modified calcium alginate microspheres.

2. The loaded modified soda saline soil conditioner according to claim 1, characterized in that: The acidified zeolite is clinoptilolite acidified with hydrochloric acid, the average particle size of the acidified zeolite is 140 mesh, and the specific surface area of the acidified zeolite is 122 to 355 m 2 / g.

3. The loaded modified soda saline soil conditioner according to claim 2, characterized in that: The preparation steps of the acidified zeolite are as follows: firstly, the clinoptilolite is acidified with a 0.5 mol / L hydrochloric acid solution for 2 hours, and then calcined at 350° C. for activation.

4. The loaded modified soda saline soil conditioner according to claim 1, characterized in that: The fulvic acid is a 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.

5. The loaded modified soda saline soil conditioner according to claim 1, characterized in that: The solid organic fertilizer is one or a combination of wheat straw powder, corn straw powder, peat, bagasse, distiller's grains, mushroom chaff, fish bone powder, oyster shell powder, seaweed fertilizer, coconut chaff, and earthworm manure.

6. The loaded 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 to 120 cSt.

7. The method for preparing the loaded modified soda saline soil conditioner according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Mixing 1: first, add the acidified zeolite to deionized water, and stir continuously at a stirring speed of 300-600 r / min for 10-20 min, then add the fulvic acid-modified calcium alginate microspheres, and stir continuously at a stirring speed of 300-600 r / min for 30-60 min to obtain a mixture A; S2. Mixing 2: First, aluminum sulfate and ferrous sulfate are added to mixture A in sequence, and then citric acid is added to mixture A. The mixture is stirred continuously at a stirring speed of 200 to 400 r / min for 20 to 30 minutes to obtain mixture B. S3. Mixing 3: First, heat mixture B to 60-75° C., 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, and adjust the moisture content of mixture C to 10%-25%; S4, granulation: feeding the mixture C into a granulator, extruding and granulating to obtain granules; S5. Drying: The granules are sent to a rotary flash dryer to remove excess water from the granules until the moisture content of the granules is reduced to 5% to 10%, and then cooled to room temperature to obtain the improver.

8. The method for preparing a loaded modified soda saline soil conditioner according to claim 1, characterized in that: The particle size of the particles is 3 to 5 mm.

9. The method for using the loaded modified soda saline soil conditioner according to any one of claims 1 to 6, characterized in that: After the autumn crops are harvested and before the soil freezes, or before the land is prepared in spring, the improver is first mechanically and evenly applied to the ground surface according to the actual amount, and then a rotary tiller is used to perform rotary tillage operations to mix the improver into a soil layer ≤20 cm.

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