A red soil paddy field acid reduction and fertilization improver, preparation method and improvement method thereof

Abstract

The present invention proposes an acid-reducing and fertilizing improver for red soil rice fields, a preparation method and an improvement method thereof, and belongs to the technical field of soil improvement. After the straw is carbonized, it is added to a urea solution, sodium alginate and carboxymethyl chitosan are added, and an injection pump is dripped into a calcium chloride solution drop by drop to obtain a gel ball, the surface of which is modified by a silane coupling agent, hydrolyzed, added to a solution containing microorganisms and biological enzymes, and freeze-dried to obtain an acid-reducing and fertilizing improver for red soil rice fields. The acid-reducing and fertilizing improver for red soil rice fields prepared by the present invention can not only effectively increase the soil pH value, improve soil fertility, improve soil structure, and promote the downward leaching of salt-damaging ions, but the straw powder can also improve the soil CO2 bias, soil air, and soil quality, and has a good slow-release effect and broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of soil improvement, and in particular to an improver for reducing acidity and improving fertility in red soil paddy fields, a preparation method and an improvement method thereof. Background Art

[0002] Jiangxi is located on the northern edge of the mid-subtropical zone, with a warm climate. At the same time, the southeast monsoon with a lot of water vapor in spring brings abundant precipitation, nourishing the earth. Under such high temperature and high humidity climate conditions, chemical weathering and leaching are very active. The rocks on the surface of the earth's crust are decomposed and leached, and oxides such as iron and lead are relatively accumulated. The growth of various plants has accelerated this change process. In this way, red soil - red soil - was formed over a long period of time. Generally, there are many four-coordinated and six-coordinated metal compounds in red soil, including iron compounds and aluminum compounds. Red soil iron compounds often include limonite and hematite, and red soil contains a lot of hematite. When rainwater washes, many compounds are washed away, but iron oxide (aluminum) is the least soluble (solubility ten to the negative thirty power). Instead, it will be coated on the clay particles layer by layer during the crystallization process and form a group of particles. It is not easy to be destroyed by rainwater erosion afterwards. Therefore, the red soil develops a good structure under the leaching of rainwater. Red soil is a zonal red soil distributed in the mid-subtropical humid areas of my country. It is a moderately desiliconized aluminum-rich ferro-alumina soil. Red soil usually has a thick red soil layer, with a well-developed reticular layer. The clay minerals are mainly kaolinite, acidic, and low in base saturation.

[0003] Over the years, research on the improvement of red soil acidity has received widespread attention, and many acidic soil conditioners have been developed, such as the use of industrial waste alkali residue and other materials combined with modification and biomass coke. However, overall, most conditioners are expensive and have a complicated preparation process. Therefore, even if these conditioners have a certain effect on improving soil acidity, their effects on increasing crop yields and improving other aspects of soil are relatively limited, which limits their application in actual production. Summary of the invention

[0004] The purpose of the present invention is to provide an acid-reducing and fertilizing improver for red soil paddy fields, a preparation method and an improvement method thereof, which can not only effectively increase the soil pH value, improve soil fertility, improve soil structure, and promote the downward leaching of salt-damaging ions, but also the straw powder can improve the soil CO2 bias, soil air, and soil quality, has a good slow-release effect, and has broad application prospects.

[0005] The technical solution of the present invention is achieved in this way:

[0006] The present invention provides a method for preparing a red soil paddy field acid-reducing and fertilization-enhancing agent, comprising the following steps:

[0007] S1. The straw is dried, crushed, mixed with potassium hydroxide, heated, calcined, and acid-washed to neutral to obtain straw charcoal powder;

[0008] S2. Add straw charcoal powder to urea solution, disperse evenly, add sodium alginate and carboxymethyl chitosan, stir and mix evenly, drip into calcium chloride solution drop by drop with a syringe pump, let stand, filter, wash, dry, and obtain gel balls; the concentration of the urea solution is 4-6wt%, the mass ratio of the straw charcoal powder, sodium alginate and carboxymethyl chitosan is 5-7:10-12:7-10, and the concentration of the calcium chloride solution is 3-4wt%;

[0009] S3. The gel balls are added to ethanol, a silane coupling agent is added, the reaction is heated and stirred, filtered, washed, and dried to obtain modified gel balls;

[0010] S4. The modified gel spheres are added to an aqueous solution containing a porogen, and hydrolyzed to obtain porous gel spheres;

[0011] S5. Adding microorganisms and biological enzymes to water, stirring and mixing to obtain a mixed solution; the microorganisms are a mixture of radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas in a mass ratio of 3-5:2-3:1-2:2-3, and the biological enzymes are a mixture of catalase, urease, sucrase, phosphatase, and cellulase in a mass ratio of 3-4:1-2:2-3:1-2:3-5; the mass ratio of the microorganisms and the biological enzymes is 3-5:1-2;

[0012] S6. The porous gel balls are added into the mixed solution, and the mixture is freeze-dried to prepare a red soil rice field acid-reducing and fertilizing agent.

[0013] As a further improvement of the present invention, in step S1, the mass ratio of the straw to potassium hydroxide is 10:2-3, the temperature of the heating and calcining is 600-700° C., and the time is 1-3 h.

[0014] As a further improvement of the present invention, in step S3, the mass ratio of the gel balls to the silane coupling agent is 10:3-4, the temperature of the heating and stirring reaction is 40-50° C., the time is 2-4 hours, and the silane coupling agent is selected from at least one of KH550, KH602, and KH792.

[0015] As a further improvement of the present invention, the mass ratio of the modified gel balls and the porogen in step S4 is 100:2-3, the porogen is selected from at least one of hexadecyltrimethylammonium chloride, hexadecyldimethylbenzylammonium chloride, and hexadecyltrimethylammonium bromide, the hydrolysis temperature is 40-50°C, and the time is 5-7h.

[0016] As a further improvement of the present invention, the solid-to-liquid ratio of the porous gel balls and the mixed solution in step S6 is 1:7-10 g / mL.

[0017] The present invention further protects a red soil paddy field acid-reducing and fertilizing improving agent prepared by the above-mentioned preparation method.

[0018] The present invention further provides a red soil paddy field acid reduction and fertilization improvement method, comprising: during land preparation, adding the red soil paddy field acid reduction and fertilization improvement agent to the soil, turning and mixing evenly, wherein the application amount of the red soil paddy field acid reduction and fertilization improvement agent is 10-12 g / m 2 The frequency of application is 1-3 times a year.

[0019] The present invention has the following beneficial effects:

[0020] Sodium alginate as the shell layer has the characteristics of non-toxicity, good biocompatibility and stability, but has low mechanical strength, swelling in water and severe burst release. The present invention prepares a red soil rice field acid reduction and fertilization improver with sodium alginate and carboxymethyl chitosan as the first shell layer. The composite material structure effectively suppresses the burst release of the capsule and has good pH responsiveness, but the mechanical strength still does not meet the requirements. Therefore, the present invention further modifies the surface of the prepared gel ball with a silane coupling agent, and after hydrolysis and the action of a porogen, a porous silicon oxide layer is formed on the surface, which greatly enhances the mechanical properties of the microspheres. At the same time, the present invention prepares straw into straw carbon powder, and introduces it into the preparation of microspheres, which can not only improve the immobilization of the improver, reduce burst release, and improve the stability of the gel ball, but also give full play to the soil improvement effect of biomass charcoal, thereby achieving the dual effects of nutrient controlled release and improving soil physical and chemical properties in practical applications.

[0021] The porous gel balls prepared by the present invention are immersed in a mixed solution containing microorganisms and biological enzymes. Since the porous gel balls have residual amino groups on the silane coupling agent, the microorganisms and biological enzymes can be loaded in the pores by forming hydrogen bonds and the like. The synergistic effect of the composite microorganisms and biological enzymes can improve the plant rhizosphere environment, reduce the inhibitory effect of salt on crop growth, thereby improving soil fertility and increasing the pH value of the soil.

[0022] The red soil paddy field acid-reducing and fertilizing improver prepared by the invention can not only effectively increase the soil pH value, improve soil fertility, improve soil structure, and promote the downward leaching of salt-damaging ions, but the straw powder can also improve soil CO2 bias, soil air, and soil quality, has a good slow-release effect, and has broad application prospects. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Radiorhizobium, ATCC336706, Pseudomonas aeruginosa, ATCC27853, Rhodospirilla, ATCC27048, Pseudomonas aeruginosa, ATCC31554.

[0025] Catalase, 400,000 U / g, urease, 50,000 U / g, sucrase, 15,000 U / g, phosphatase, 10,000 U / g, cellulase, 50,000 U / g.

[0026] Example 1

[0027] This embodiment provides a method for preparing a red soil paddy field acid-reducing and fertilization-enhancing agent, comprising the following steps:

[0028] S1. 10g corn straw was dried, crushed, mixed with 2g potassium hydroxide, heated to 600℃, calcined for 1h, and acid-washed to neutrality to obtain straw charcoal powder;

[0029] S2. 5 g of straw charcoal powder was added to 100 mL of 4 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 10 g of sodium alginate and 7 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0030] S3. Add 10 g of gel spheres to 200 mL of ethanol, add 3 g of silane coupling agent KH550, heat to 40°C, stir to react for 2 h, filter, wash, and dry to obtain modified gel spheres;

[0031] S4. 10 g of the modified gel spheres were added to 200 mL of an aqueous solution containing 0.2 g of hexadecyldimethylbenzylammonium chloride, and hydrolyzed at 40° C. for 5 h to obtain porous gel spheres;

[0032] S5. 3 g of microorganisms and 1 g of enzyme were added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0033] The microorganisms are radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas in a mass ratio of 3:2:1:2;

[0034] The biological enzyme is a mixture of catalase, urease, sucrase, phosphatase and cellulase in a mass ratio of 3:1:2:1:3;

[0035] S6. 10 g of porous gel balls were added to 70 mL of the mixed solution, and freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0036] Example 2

[0037] This embodiment provides a method for preparing a red soil paddy field acid-reducing and fertilization-enhancing agent, comprising the following steps:

[0038] S1. 10g corn straw was dried, crushed, mixed with 3g potassium hydroxide, heated to 700℃, calcined for 3h, and acid-washed to neutrality to obtain straw charcoal powder;

[0039] S2. 7 g of straw charcoal powder was added to 100 mL of 6 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 12 g of sodium alginate and 10 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 4 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0040] S3. Add 10 g of gel spheres to 200 mL of ethanol, add 4 g of silane coupling agent KH602, heat to 50° C., stir to react for 4 h, filter, wash, and dry to obtain modified gel spheres;

[0041] S4. 10 g of the modified gel spheres were added to 200 mL of an aqueous solution containing 0.3 g of hexadecyltrimethylammonium bromide, and hydrolyzed at 50° C. for 7 h to obtain porous gel spheres;

[0042] S5. 5 g of microorganisms and 2 g of enzymes were added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0043] The microorganisms are radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas in a mass ratio of 5:3:2:3;

[0044] The biological enzyme is a mixture of catalase, urease, sucrase, phosphatase and cellulase, with a mass ratio of 4:2:3:2:5;

[0045] S6. 10 g of porous gel balls were added into 100 mL of the mixed solution, and the mixture was freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0046] Example 3

[0047] This embodiment provides a method for preparing a red soil paddy field acid-reducing and fertilization-enhancing agent, comprising the following steps:

[0048] S1. 10g corn straw was dried, crushed, mixed with 2.5g potassium hydroxide, heated to 650°C, calcined for 2h, and acid-washed to neutrality to obtain straw charcoal powder;

[0049] S2. 6 g of straw charcoal powder was added to 100 mL of 5 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 11 g of sodium alginate and 8 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3.5 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0050] S3. 10 g of gel spheres were added to 200 mL of ethanol, 3.5 g of silane coupling agent KH792 was added, the mixture was heated to 45°C, stirred for reaction for 3 h, filtered, washed, and dried to obtain modified gel spheres;

[0051] S4. 10 g of the modified gel spheres were added to 200 mL of an aqueous solution containing 0.25 g of hexadecyltrimethylammonium chloride, and hydrolyzed at 45° C. for 6 h to obtain porous gel spheres;

[0052] S5. 4 g of microorganisms and 1.5 g of enzyme were added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0053] The microorganisms are radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas, with a mass ratio of 4:2.4:1.5:2.5;

[0054] The biological enzyme is a mixture of catalase, urease, sucrase, phosphatase and cellulase, with a mass ratio of 3.6:1.4:2.8:1.2:4;

[0055] S6. 10 g of porous gel balls were added to 85 mL of the mixed solution, and freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0056] Comparative Example 1

[0057] Compared with Example 3, the difference is that carboxymethyl chitosan is not added in step S2.

[0058] The details are as follows:

[0059] S2. Add 6 g of straw charcoal powder into 100 mL of urea solution, disperse it ultrasonically at 1000 W for 10 min, add 19 g of sodium alginate, stir and mix for 10 min, drip it dropwise into 3.5 wt% calcium chloride solution with a syringe pump, let it stand for 1 h, filter, wash and dry to obtain gel spheres.

[0060] Comparative Example 2

[0061] Compared with Example 3, the difference is that steps S3 and S4 are not performed.

[0062] The details are as follows:

[0063] S1. 10g corn straw was dried, crushed, mixed with 2.5g potassium hydroxide, heated to 650°C, calcined for 2h, and acid-washed to neutrality to obtain straw charcoal powder;

[0064] S2. 6 g of straw charcoal powder was added to 100 mL of 5 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 11 g of sodium alginate and 8 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3.5 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0065] S3. 4 g of microorganisms and 1.5 g of enzyme were added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0066] The microorganisms are radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas, with a mass ratio of 4:2.4:1.5:2.5;

[0067] The biological enzyme is a mixture of catalase, urease, sucrase, phosphatase and cellulase, with a mass ratio of 3.6:1.4:2.8:1.2:4;

[0068] S4. 10 g of gel balls were added into 85 mL of the mixed solution, and the mixture was freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0069] Comparative Example 3

[0070] Compared with Example 3, the difference is that no microorganisms are added in step S5.

[0071] The details are as follows:

[0072] S1. 10g corn straw was dried, crushed, mixed with 2.5g potassium hydroxide, heated to 650°C, calcined for 2h, and acid-washed to neutrality to obtain straw charcoal powder;

[0073] S2. 6 g of straw charcoal powder was added to 100 mL of 5 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 11 g of sodium alginate and 8 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3.5 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0074] S3. 10 g of gel spheres were added to 200 mL of ethanol, 3.5 g of silane coupling agent KH792 was added, the mixture was heated to 45°C, stirred for reaction for 3 h, filtered, washed, and dried to obtain modified gel spheres;

[0075] S4. 10 g of the modified gel spheres were added to 200 mL of an aqueous solution containing 0.25 g of hexadecyltrimethylammonium chloride, and hydrolyzed at 45° C. for 6 h to obtain porous gel spheres;

[0076] S5. 5.5 g of the enzyme was added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0077] The biological enzyme is a mixture of catalase, urease, sucrase, phosphatase and cellulase, with a mass ratio of 3.6:1.4:2.8:1.2:4;

[0078] S6. 10 g of porous gel balls were added to 85 mL of the mixed solution, and freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0079] Comparative Example 4

[0080] Compared with Example 3, the difference is that no biological enzyme is added in step S5.

[0081] The details are as follows:

[0082] S1. 10g corn straw was dried, crushed, mixed with 2.5g potassium hydroxide, heated to 650°C, calcined for 2h, and acid-washed to neutrality to obtain straw charcoal powder;

[0083] S2. 6 g of straw charcoal powder was added to 100 mL of 5 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 11 g of sodium alginate and 8 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3.5 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0084] S3. 10 g of gel spheres were added to 200 mL of ethanol, 3.5 g of silane coupling agent KH792 was added, the mixture was heated to 45°C, stirred for reaction for 3 h, filtered, washed, and dried to obtain modified gel spheres;

[0085] S4. 10 g of the modified gel spheres were added to 200 mL of an aqueous solution containing 0.25 g of hexadecyltrimethylammonium chloride, and hydrolyzed at 45° C. for 6 h to obtain porous gel spheres;

[0086] S5. 5.5 g of microorganisms were added to 100 mL of water and stirred for 10 min to obtain a mixed solution;

[0087] The microorganisms are radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas, with a mass ratio of 4:2.4:1.5:2.5;

[0088] S6. 10 g of porous gel balls were added to 85 mL of the mixed solution, and freeze-dried to prepare a red soil rice field acid-reducing and fertilization-enhancing agent.

[0089] Comparative Example 5

[0090] Compared with the embodiment 3, the difference is that steps S5 and S6 are not performed.

[0091] The details are as follows:

[0092] S1. 10g corn straw was dried, crushed, mixed with 2.5g potassium hydroxide, heated to 650°C, calcined for 2h, and acid-washed to neutrality to obtain straw charcoal powder;

[0093] S2. 6 g of straw charcoal powder was added to 100 mL of 5 wt% urea solution, ultrasonically dispersed at 1000 W for 10 min, 11 g of sodium alginate and 8 g of carboxymethyl chitosan were added, stirred and mixed for 10 min, and dripped dropwise into 3.5 wt% calcium chloride solution with a syringe pump, allowed to stand for 1 h, filtered, washed, and dried to obtain gel spheres;

[0094] S3. 10 g of gel spheres were added to 200 mL of ethanol, 3.5 g of silane coupling agent KH792 was added, the mixture was heated to 45°C, stirred for reaction for 3 h, filtered, washed, and dried to obtain modified gel spheres;

[0095] S4. Add 10 g of the modified gel spheres into 200 mL of an aqueous solution containing 0.25 g of hexadecyltrimethylammonium chloride, and hydrolyze at 45°C for 6 h to obtain porous gel spheres, which are the acid-reducing and fertilizing improver for red soil rice fields.

[0096] Test Example 1

[0097] The specific surface area and pore volume of the red soil rice field acid-reducing and fertilizing improver prepared in Example 11-3 and Comparative Examples 1-5 were measured using an ASAP2460 fully automatic specific surface and porosity analyzer produced by Micromeritics Instruments, Inc., USA.

[0098] The results are shown in Table 1.

[0099] Table 1

[0100]

[0101] It can be seen from the above table that the red soil rice field acid-reducing and fertilizing improver prepared in Examples 1-3 of the present invention has a larger specific surface area and pore volume.

[0102] Example 4

[0103] A red soil paddy field acid reduction and fertilization improvement method, during land preparation, the red soil paddy field acid reduction and fertilization improvement agent prepared in Example 1 is added to the soil, and the soil is turned and mixed evenly. The application amount of the red soil paddy field acid reduction and fertilization improvement agent is 10g / m 2 , the frequency of application is once a year.

[0104] Example 5

[0105] A red soil paddy field acid reduction and fertilization improvement method, during land preparation, the red soil paddy field acid reduction and fertilization improvement agent prepared in Example 2 is added to the soil, and the soil is turned over and mixed evenly. The application amount of the red soil paddy field acid reduction and fertilization improvement agent is 12g / m 2 , the frequency of application is once a year.

[0106] Example 6

[0107] A red soil paddy field acid reduction and fertilization improvement method, during land preparation, the red soil paddy field acid reduction and fertilization improvement agent prepared in Example 3 is added to the soil and mixed evenly. The application amount of the red soil paddy field acid reduction and fertilization improvement agent is 11g / m 2 , the frequency of application is once a year.

[0108] Comparative Example 6

[0109] Compared with Example 6, the difference is that the red soil rice field acid-reducing and fertilizing improving agent is prepared from Comparative Example 1.

[0110] Comparative Example 7

[0111] Compared with Example 6, the difference is that the red soil rice field acid-reducing and fertilizing improving agent is prepared from Comparative Example 2.

[0112] Comparative Example 8

[0113] Compared with Example 6, the difference is that the red soil rice field acid-reducing and fertilizing improving agent is prepared from Comparative Example 3.

[0114] Comparative Example 9

[0115] Compared with Example 6, the difference is that the red soil rice field acid-reducing and fertilizing improving agent is prepared from Comparative Example 4.

[0116] Comparative Example 10

[0117] Compared with Example 6, the difference is that the red soil rice field acid-reducing and fertilizing improving agent is prepared from Comparative Example 5.

[0118] Test Example 2

[0119] The soil properties of Examples 4-6 and Comparative Examples 6-10 were tested 120 days after the soils were improved. The results are shown in Table 2.

[0120] Table 2

[0121]

[0122] It can be seen from the above table that the improved methods in Examples 4-6 of the present invention can significantly reduce the acidity of red soil and increase the content of soil active substances.

[0123] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a red soil paddy field acid-reducing and fertilization-enhancing agent, characterized in that: The following steps are involved: S1. The straw is dried, crushed, mixed with potassium hydroxide, heated and calcined, and acid-washed to neutrality to obtain straw charcoal powder; the mass ratio of the straw to potassium hydroxide is 10:2-3; the heating and calcining temperature is 600-700°C and the time is 1-3h; S2. Add straw charcoal powder to urea solution, disperse evenly, add sodium alginate and carboxymethyl chitosan, stir and mix evenly, drip into calcium chloride solution drop by drop with a syringe pump, let stand, filter, wash, dry, and obtain gel balls; the concentration of the urea solution is 4-6wt%, the mass ratio of the straw charcoal powder, sodium alginate and carboxymethyl chitosan is 5-7:10-12:7-10, and the concentration of the calcium chloride solution is 3-4wt%; S3. adding the gel balls to ethanol, adding a silane coupling agent, heating and stirring to react, filtering, washing, and drying to obtain modified gel balls; the mass ratio of the gel balls to the silane coupling agent is 10:3-4; the temperature of the heating and stirring reaction is 40-50° C., the time is 2-4 hours, and the silane coupling agent is selected from at least one of KH550, KH602, and KH792; S4. Adding the modified gel balls to an aqueous solution containing a porogen, hydrolyzing, and obtaining porous gel balls; the mass ratio of the modified gel balls to the porogen is 100:2-3; the porogen is selected from at least one of hexadecyltrimethylammonium chloride, hexadecyldimethylbenzylammonium chloride, and hexadecyltrimethylammonium bromide, the hydrolysis temperature is 40-50° C., and the time is 5-7 hours; S5. Adding microorganisms and biological enzymes to water, stirring and mixing to obtain a mixed solution; the microorganisms are a mixture of radiorhizobium, Pseudomonas aeruginosa, Rhodospirilla, and Pseudomonas in a mass ratio of 3-5:2-3:1-2:2-3, and the biological enzymes are a mixture of catalase, urease, sucrase, phosphatase, and cellulase in a mass ratio of 3-4:1-2:2-3:1-2:3-5; the mass ratio of the microorganisms and the biological enzymes is 3-5:1-2; S6. The porous gel balls are added to the mixture and freeze-dried to obtain a red soil paddy field acid-reducing and fertilizing agent; the solid-liquid ratio of the porous gel balls to the mixture is 1:7-10g / mL.

2. A red soil rice field acid-reducing and fertilizing improver prepared by the preparation method as claimed in claim 1.

3. A method for improving red soil rice fields by reducing acidity and improving fertility, characterized in that: include: During land preparation, the red soil rice field acid-reducing and fertilizing improver according to claim 2 is added to the soil and mixed evenly. The application amount of the red soil rice field acid-reducing and fertilizing improver is 10-12 g / m 2 The frequency of application is 1-3 times a year.

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