Preparation method of straw-derived organic calcium conditioner and application thereof in red acid soil hardening repair

Abstract

The present application relates to the field of agricultural technology, and provides a preparation method of a straw-derived organic calcium conditioner and application of the straw-derived organic calcium conditioner in red soil hardening repair, solves the problem that existing conditioners do not have a slow-release effect, and the effect of red soil hardening reduction, acid improvement and crop yield increase after application of the conditioner is poor, and comprises the following steps: S1, raw material pretreatment and compounding: pulverizing rice straw and mixing the rice straw with oyster shell powder to obtain mixed raw materials; S2, pyrolysis treatment is performed on the mixed raw materials, and volatile components generated in the pyrolysis process are recovered through a condensation system; S3, organic acid activation: the pyrolysis and carbonization products are mixed with an organic acid activation liquid to obtain activated carbonization products; S4, chimeric and mechanical activation: the activated carbonization products are mixed with polyethylene glycol and subjected to ball milling treatment; S5, polymer cross-linking reaction: polyvinyl alcohol and citric acid are added and mixed for reaction; and S6, shaping and granulation: shaping treatment is performed to obtain the straw-derived organic calcium conditioner.

Description

Technical Field

[0001] This invention relates to the field of agricultural technology, and in particular to a method for preparing a straw-derived organic calcium conditioner and its application in the remediation of compacted acidic red soil. Background Technology

[0002] Soil compaction and acidification are serious challenges facing global agricultural production, especially in intensive agricultural areas. This problem is particularly prominent in the vast red soil regions of southern my country. Red soil, formed under hot and rainy climates, inherently possesses characteristics such as heavy texture, high acidity, and low organic matter content. In recent years, driven by market demand, the pursuit of high yields has led to over-reliance on chemical fertilizers, neglect of organic fertilizer input, and inappropriate irrigation methods, further exacerbating these soil problems.

[0003] Excessive application of physiologically acidic fertilizers (such as ammonium sulfate and potassium chloride) is one of the direct causes of soil acidification. The acid radicals in these fertilizers (such as SO42-) contribute to soil acidification. 2- Cl - Accumulation of these substances in the soil, combined with hydrogen ions, leads to a decrease in pH. Simultaneously, the excessive application of chemical fertilizers disrupts the soil's aggregate structure, causing soil compaction, characterized by increased soil bulk density, reduced porosity, and deteriorated aeration and water permeability. This creates a vicious cycle: compacted soil inhibits crop root respiration and extension, limiting nutrient and water absorption, which in turn necessitates the application of even more fertilizer to maintain yield, further exacerbating compaction and acidification. The multiple harms of soil compaction and acidification to crop production include: reduced nutrient availability, aluminum and manganese ion toxicity, suppressed microbial activity, and water-air imbalance.

[0004] Chinese Patent Publication No. CN119977712A discloses a paddy field soil conditioner and its application. The paddy field soil conditioner is composed of compound fertilizer and compound microbial agent. By weight, the compound fertilizer is a mixture of the following components: 20-30 parts rice husk biochar, 20-30 parts shell powder, and 10-15 parts potassium humate. The compound microbial agent is a mixture of the following components: 3-4 parts *Bacillus polymyxa*, 2-3 parts *Bacillus marineus*, and 1.5-2 parts *Bacillus stolonifer*. This invention's soil conditioner, composed of compound fertilizer and compound microbial agent, wherein the compound microbial agent is a mixture of three microbial agents—*Bacillus polymyxa*, *Bacillus marineus*, and *Bacillus stolonifer*—helps improve soil fertility, increase the thousand-grain weight of rice, and thus increase rice yield. However, because this conditioner contains compound microbial agent, its survival rate and colonization ability may be poor in highly acidic red soil with high aluminum and manganese content.

[0005] Chinese Patent Publication No. CN120192195A discloses a high-carbon bio-organic conditioner and its application in red soil peanut cultivation. The high-carbon bio-organic conditioner is composed of mineral powder, oyster shell powder, zeolite powder, potassium humate, well-rotted cow manure, alanine, and glycine in a mass ratio of 800:200:10:50:140:0.7:0.5. The organic matter content of the high-carbon bio-organic conditioner is not less than 45 wt.%, the humic acid content is 20 wt.%, and it contains Bacillus subtilis. This invention, through the application of the high-carbon bio-organic conditioner, achieves a rapid improvement in soil quality and a significant increase in peanut yield in red soil peanut cultivation areas. However, this conditioner does not possess slow-release Ca2+. 2+ The results were not satisfactory, and a complete deep loosening-conditioning-drip irrigation synergistic technology system was not formed. At the same time, the product form of the conditioner was not clearly defined. If it is a powder, it is easy to generate dust, resulting in uneven application, and it is easily washed away by rain or scattered by the wind. Summary of the Invention

[0006] Therefore, in view of the above problems, the present invention provides a method for preparing a straw-derived organic calcium conditioner and its application in the remediation of acidic red soil compaction, which solves the problems that existing conditioners do not have a slow-release effect and are not effective in reducing red soil compaction, improving acidity and increasing crop yield after the conditioner is applied.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing a straw-derived organic calcium conditioner includes the following steps:

[0009] S1. Raw material pretreatment and compounding: Rice straw is crushed and mixed with oyster shell powder to obtain mixed raw materials. The oyster shell powder is obtained by washing and drying waste oyster shells and crushing them through an 800-mesh sieve.

[0010] S2, Anaerobic pyrolysis and volatile matter recovery: The mixed raw material obtained in step S1 is pyrolyzed under nitrogen protection at a temperature of 400℃-600℃ for 1-2 hours to obtain pyrolysis carbonization products. The volatile matter generated during the pyrolysis process is recovered through a condensation system to obtain wood vinegar condensate.

[0011] S3, Organic acid activation: The pyrolysis carbonization product obtained in step S2 is mixed with the organic acid activation solution and stirred at 70℃-80℃ for 2h-3h. After the reaction is completed, the solid is separated and washed until neutral to obtain the activated carbonization product.

[0012] S4. Integration and mechanical activation: The activated carbonized product obtained in step S3 is dry-mixed with polyethylene glycol and ball-milled to obtain a first mixture.

[0013] S5. Polymer crosslinking reaction: Polyvinyl alcohol and citric acid are added to the first mixture obtained in step S4, deionized water is sprayed, and the mixture is stirred at 85℃-90℃ for 30min-60min to obtain the second mixture.

[0014] S6. Shaping and Granulation: The second mixture obtained in step S5 is subjected to shaping treatment to obtain straw-derived organic calcium conditioner.

[0015] The molding process is as follows: melt extrusion granulation is performed by a twin-screw extruder at 110℃-120℃, or cylindrical granules are formed by a tablet press at 10MPa pressure, and then cooled and solidified to obtain straw-derived organic calcium conditioner.

[0016] Furthermore, the straw-derived organic calcium conditioner comprises the following raw materials in parts by weight: 50-65 parts rice straw powder, 15-25 parts oyster shell powder, 30-50 parts organic acid activation liquid, 5-15 parts polyethylene glycol, 3-8 parts polyvinyl alcohol, 1-3 parts citric acid, and 10-20 parts deionized water.

[0017] The main ingredient in the straw-derived organic calcium conditioner, rice straw powder, releases potassium (K) when it decomposes in the soil. + Ca 2+ Mg 2+ Isobasic ions, these ions can react with acidifying H+ adsorbed on soil colloids. + and aluminum ions Al 3+ It utilizes bio-exchange to leach aluminum, gradually increasing soil pH and mitigating aluminum toxicity; it is a gentle acidification method, avoiding the drastic pH fluctuations and compaction risks that may result from lime application; oyster shell powder, whose main component is CaCO3, can directly and persistently neutralize H+ in the soil. + This effectively increases soil pH, improving the acidic environment to a range suitable for most crops.

[0018] Furthermore, the straw-derived organic calcium conditioner is a regular cylindrical particle with a diameter of 4mm-10mm and a height of 3-5mm.

[0019] Furthermore, in step S3, the organic acid activation solution is prepared by mixing wood vinegar condensate and humic acid in a volume ratio of 1-3:1.

[0020] The application of the straw-derived organic calcium conditioner prepared by the above-described method in the remediation of compacted acidic red soil includes the following steps:

[0021] (a) Deep loosening operation: Use a soil loosening machine to loosen the compacted red soil, with a deep loosening depth of 30cm-40cm;

[0022] (b) Application and mixing: The prepared straw-derived organic calcium conditioner is applied evenly to the surface of the deep-loosened soil at a rate of 30 kg / mu to 50 kg / mu, and then evenly mixed into the soil layer of 5 cm to 20 cm by a rotary tiller.

[0023] (c) Drip irrigation activation: Within 3-7 days after the completion of step (b), the first drip irrigation is carried out using an integrated water and fertilizer drip irrigation system to bring the soil moisture content to 70%-85% of the field capacity;

[0024] (d) Sowing or seedling transplanting: Apply slow-release compound fertilizer before sowing or seedling transplanting, and adopt a wide and narrow row planting pattern, with a row spacing of 60cm-80cm for wide rows and 30cm-40cm for narrow rows;

[0025] (e) Water and fertilizer management: Apply high-potassium water-soluble fertilizer through the integrated water and fertilizer drip irrigation system during the critical growth period of the crop.

[0026] Furthermore, the soil loosening machine includes a frame, a deep loosening shovel, a soil-crushing roller, and rolling wheels. The front end of the frame includes one or more rows of deep loosening shovels. The soil-crushing roller is connected to the rear of the frame via a three-point suspension mechanism. The rolling wheels are located on both sides of the soil-crushing roller. The deep loosening shovel includes a double-winged arrow-shaped shovel tip and a shovel handle. The shovel handle of the deep loosening shovel has a backward-curved arc structure, and its end is hinged to the frame to form an adjustable tilt angle connection mechanism. The surface of the soil-crushing roller has multiple sets of soil-crushing blades spirally distributed along the circumference, and the two ends of the soil-crushing roller are connected to the axle of the rolling wheels via bushings to form a linkage rotation structure.

[0027] Furthermore, the slow-release compound fertilizer has an N:P2O5:K2O ratio of 12:15:18, a dosage of 15kg / mu-25kg / mu, an application depth of 5cm-8cm, and is kept 3cm-5cm away from the seedlings to prevent burning.

[0028] Furthermore, the high-potassium water-soluble fertilizer has an N:P2O5:K2O ratio of 10:10:30, and the amount of fertilizer applied each time is 5kg / mu-8kg / mu, combined with drip irrigation.

[0029] Furthermore, after the seedlings are transplanted, irrigation begins when the soil moisture content is below 60% of the field water holding capacity and stops when the field water holding capacity is reached. The irrigation water source is treated by a vortex micro-nano bubble generator to generate micro-nano bubble water with a dissolved oxygen concentration maintained at 9mg / L-15mg / L.

[0030] By adopting the aforementioned technical solution, the beneficial effects of the present invention are as follows:

[0031] (1) Oyster shells and straw are combined for synergistic pyrolysis, and the volatile wood vinegar (rich in acetic acid, phenols and other organic acids) generated by pyrolysis is systematically recovered. It is then combined with humic acid to form a green, environmentally friendly, low-cost and highly active composite organic acid activation liquid. Straw is converted into porous biochar. After these biochar particles are applied to the soil, they serve as a stable "skeleton" material, which can effectively disperse heavy soil particles, making the soil loose and fundamentally alleviating physical compaction.

[0032] (2) Polyethylene glycol is used as a pore-forming agent and toughening agent. It is embedded in the pores of carbonized products during ball milling. After being applied to the soil, it can slowly dissolve, thus leaving more and richer pore structures inside and on the surface of the material, which greatly improves the water retention and adsorption of the conditioner. Polyvinyl alcohol is used as a green binder and coating material. It is thermally crosslinked under the catalysis of citric acid to form a three-dimensional network structure, which firmly binds the carbonized particles together and can form a slow-release film on the particle surface to delay the excessive release of calcium ions.

[0033] (3) Conditioner is granulated by extrusion or compression to obtain granules with moderate strength and uniform size, which is very convenient for mechanical application. The granules can form a better pore structure in the soil and are less likely to generate dust.

[0034] (4) This technical solution forms a process system from deep soil loosening, conditioner application, water and fertilizer management to crop planting. It is a comprehensive solution specifically designed to efficiently solve the comprehensive problems of "acidity, compaction, and poor soil" in red soil, rather than a simple fertilizer or single-function improver. It can effectively reduce red soil compaction, improve acidity, and increase crop yield, making it easy to promote and apply on a large scale. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the soil loosening machine in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the soil-crushing roller in an embodiment of the present invention;

[0037] The labels in the diagram are as follows: frame (1), deep loosening shovel (2), soil breaking roller (3), rolling wheel (4), double-wing arrow-shaped shovel tip (21), shovel handle (22), soil breaking blade (31). Detailed Implementation

[0038] Example 1

[0039] A method for preparing a straw-derived organic calcium conditioner includes the following steps:

[0040] S1. Raw material pretreatment and compounding: Rice straw is crushed and mixed with oyster shell powder to obtain mixed raw materials. The oyster shell powder is obtained by washing and drying waste oyster shells and crushing them through an 800-mesh sieve.

[0041] S2, Anaerobic pyrolysis and volatile matter recovery: The mixed raw material obtained in step S1 is pyrolyzed under nitrogen protection at a temperature of 400°C for 2 hours to obtain pyrolysis carbonization products. The volatile matter generated during the pyrolysis process is recovered through a condensation system to obtain wood vinegar condensate.

[0042] S3, Organic acid activation: The pyrolysis carbonization product obtained in step S2 is mixed with the organic acid activation solution and stirred at 70°C for 2 hours. After the reaction is completed, the solid is separated and washed until neutral to obtain the activated carbonization product.

[0043] S4. Integration and mechanical activation: The activated carbonized product obtained in step S3 is dry-mixed with polyethylene glycol and ball-milled to obtain a first mixture.

[0044] S5. Polymer crosslinking reaction: Polyvinyl alcohol and citric acid are added to the first mixture obtained in step S4, deionized water is sprayed, and the mixture is stirred at 85°C for 30 min to obtain the second mixture.

[0045] S6. Shaping and Granulation: The second mixture obtained in step S5 is subjected to molding treatment to obtain straw-derived organic calcium conditioner; the molding treatment is: melt extrusion granulation at 120°C using a twin-screw extruder, followed by cooling and solidification to obtain straw-derived organic calcium conditioner.

[0046] In step S3, the organic acid activation solution is prepared by mixing wood vinegar condensate and humic acid in a volume ratio of 1:1.

[0047] The straw-derived organic calcium conditioner comprises the following raw materials in parts by weight: 50 parts rice straw powder, 15 parts oyster shell powder, 30 parts organic acid activation liquid, 5 parts polyethylene glycol, 3 parts polyvinyl alcohol, 1 part citric acid, and 10 parts deionized water.

[0048] The straw-derived organic calcium conditioner is in the form of regular cylindrical particles with a diameter of 10 mm and a height of 5 mm.

[0049] The application of the straw-derived organic calcium conditioner prepared by the above-described method in the remediation of compacted acidic red soil includes the following steps:

[0050] (a) Overview of the test site: The test was conducted in Wuyishan City, Fujian Province. The region has a subtropical monsoon climate with an average annual precipitation of 1850 mm and an average annual temperature of 18.5℃. The soil tested was a typical hilly red soil developed from granite parent material, and the land use was dryland farming.

[0051] (b) Basic physical and chemical properties of soil: The sampling depth was 0-20cm. The test results are shown in Table 2. The strong acid environment inhibited the availability of nutrients, and the high clay content led to soil compaction.

[0052] (c) Deep loosening operation: Use a soil loosening machine to loosen the compacted red soil, with a deep loosening depth of 30cm-40cm;

[0053] (d) Application and mixing: The prepared straw-derived organic calcium conditioner is evenly applied to the surface of the deep-loosened soil at a rate of 30 kg / mu, and then evenly mixed into the soil layer of 5cm-20cm by a rotary tiller.

[0054] (e) Drip irrigation activation: Three days after step (d) is completed, the first drip irrigation is carried out using an integrated water and fertilizer drip irrigation system to bring the soil moisture content to 75% of the field capacity;

[0055] (f) Sowing: Apply slow-release compound fertilizer before sowing peanuts and adopt a wide and narrow row planting pattern, with a row spacing of 80cm for wide rows and 40cm for narrow rows;

[0056] (g) Water and fertilizer management: During the critical growth period of peanuts, high-potassium water-soluble fertilizer is applied as topdressing through the integrated water and fertilizer drip irrigation system.

[0057] Among them, reference Figures 1 to 2 The soil loosening machine includes a frame (1), a deep loosening shovel (2), a soil crushing roller (3), and a rolling wheel (4). The front end of the frame (1) includes a double-row deep loosening shovel (2). The soil crushing roller (3) is connected to the rear of the frame (1) through a three-point suspension mechanism. The rolling wheel (4) is located on both sides of the soil crushing roller (3). The deep loosening shovel (2) includes a double-winged arrow-shaped shovel tip (21) and a shovel handle (22). The shovel handle (22) of the deep loosening shovel (2) is an arc-shaped structure that bends backward. Its end is hinged to the frame (1) to form an adjustable tilt angle connection mechanism. The surface of the soil crushing roller (3) has multiple sets of soil crushing blades (31) spirally distributed along the circumference. The two ends of the soil crushing roller (3) are connected to the wheel axle of the rolling wheel (4) through bushings to form a linkage rotation structure.

[0058] The slow-release compound fertilizer has an N:P2O5:K2O ratio of 12:15:18, a dosage of 15 kg / mu, an application depth of 8 cm, and is kept 5 cm away from the seedlings to prevent burning. The high-potassium water-soluble fertilizer has an N:P2O5:K2O ratio of 10:10:30, with a top dressing amount of 5 kg / mu, applied in conjunction with drip irrigation. After transplanting the seedlings, irrigation begins when the soil moisture content is below 60% of the field water holding capacity and stops when the field water holding capacity is reached. The irrigation water source for each irrigation is treated by a vortex micro-nano bubble generator to generate micro-nano bubble water with a dissolved oxygen concentration maintained at 9 mg / L.

[0059] Example 2

[0060] The difference from Example 1 is as follows: the pyrolysis temperature is 500℃; the organic acid activation liquid is a mixture of wood vinegar condensate and humic acid in a volume ratio of 2:1; the straw-derived organic calcium conditioner includes the following raw materials in parts by weight: 65 parts rice straw powder, 25 parts oyster shell powder, 40 parts organic acid activation liquid, 10 parts polyethylene glycol, 5 parts polyvinyl alcohol, 2 parts citric acid, and 15 parts deionized water; the straw-derived organic calcium conditioner is applied evenly to the surface of the soil after deep loosening at a dosage of 40 kg / mu; the irrigation water source is treated by a vortex-type micro-nano bubble generator to generate micro-nano bubble water with a dissolved oxygen concentration maintained at 12 mg / L. Other technical solutions are the same as in Example 1.

[0061] Example 3

[0062] The difference from Example 1 is as follows: the pyrolysis temperature is 600℃; the organic acid activation liquid is a mixture of wood vinegar condensate and humic acid in a volume ratio of 3:1; the straw-derived organic calcium conditioner includes the following raw materials in parts by weight: 55 parts rice straw powder, 20 parts oyster shell powder, 50 parts organic acid activation liquid, 15 parts polyethylene glycol, 8 parts polyvinyl alcohol, 3 parts citric acid, and 20 parts deionized water; the straw-derived organic calcium conditioner is applied evenly to the surface of the soil after deep loosening at a dosage of 50 kg / mu; the irrigation water source is treated by a vortex-type micro-nano bubble generator to generate micro-nano bubble water with a dissolved oxygen concentration maintained at 12 mg / L during each irrigation. Other technical solutions are the same as in Example 1.

[0063] Comparative Example 1

[0064] The difference from Example 1 is that the straw-derived organic calcium conditioner prepared by this technical solution is not used. All other technical solutions are the same as in Example 1.

[0065] Comparative Example 2

[0066] The difference from Example 1 is that the water filling does not undergo treatment by a vortex-type micro / nano bubble generator. All other technical solutions are the same as in Example 1.

[0067] Comparative Example 3

[0068] The difference from Example 2 is that the straw-derived organic calcium conditioner prepared by this technical solution is not used. All other technical solutions are the same as in Example 2.

[0069] Comparative Example 4

[0070] The difference from Example 2 is that the water filling does not undergo treatment with a swirling micro / nano bubble generator. All other technical aspects are the same as in Example 2.

[0071] Comparative Example 5

[0072] The difference from Example 3 is that the straw-derived organic calcium conditioner prepared by this technical solution is not used. All other technical solutions are the same as in Example 3.

[0073] Comparative Example 6

[0074] The difference from Example 3 is that the water is not treated by a swirling micro / nano bubble generator. All other technical aspects are the same as in Example 3.

[0075] After a growing season (120 days), yield and quality analysis were conducted during the crop growth and harvest period, and the results are shown in Table 1.

[0076] Table 1

[0077]

[0078] Test standard reference:

[0079] (1) Peanut yield: NY / T 1088-2020 Technical Specifications for Peanut Yield Survey;

[0080] (2) Plant height: NY / T 2368-2013 Technical Specifications for Field Trials of Soil and Fertilizer Biology;

[0081] (3) Root activity: NY / T 2017-2011 "Determination of plant root activity by TTC method";

[0082] (4) Weight of 100 kernels: GB / T 5499-2023 "Determination of Test Density of Grains and Oils" and GB 4407.2-2024 "Economic Crop Seeds Part 2: Oilseeds";

[0083] (5) Crude protein content: GB 5009.5-2016 National Food Safety Standard - Determination of Protein in Food.

[0084] Basic physicochemical properties of the soil were tested 15 days after peanut sowing and after peanut harvest. The test results are shown in Table 2.

[0085] Table 2

[0086]

[0087] The experimental results of Examples 1 to 3 show that the soil physicochemical properties were significantly improved after the application of straw-derived organic calcium conditioner compared to the soil conditions before the experiment. Specifically:

[0088] (1) It can effectively increase the soil pH value and improve the strongly acidic red soil (pH 5.2) to weakly acidic (pH 6.5) during the crop growing season.

[0089] (2) Straw-derived organic calcium conditioner can effectively reduce soil bulk density (from 1.52 g / cm3 to 1.28 g / cm3) and increase porosity through its organic matter and granular structure, thus improving the problem of heavy and compacted red soil.

[0090] (3) The straw-derived organic calcium conditioner and its application method can increase peanut yield to 352.4 kg / mu, which is 25.7% higher than the baseline control (comparative example 1).

[0091] In summary, this technical solution demonstrates significant application value in addressing soil compaction in acidic red soil in southern China and improving crop yields.

[0092] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art will understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for preparing a straw-derived organic calcium conditioner, characterized in that, Includes the following steps: S1. Raw material pretreatment and compounding: Rice straw is crushed and mixed with oyster shell powder to obtain mixed raw materials. The oyster shell powder is obtained by washing and drying waste oyster shells and crushing them through an 800-mesh sieve. S2, Anaerobic pyrolysis and volatile matter recovery: The mixed raw material obtained in step S1 is pyrolyzed under nitrogen protection at a temperature of 400℃-600℃ for 1-2 hours to obtain pyrolysis carbonization products. The volatile matter generated during the pyrolysis process is recovered through a condensation system to obtain wood vinegar condensate. S3, Organic acid activation: The pyrolysis carbonization product obtained in step S2 is mixed with the organic acid activation solution and stirred at 70℃-80℃ for 2h-3h. After the reaction is completed, the solid is separated and washed until neutral to obtain the activated carbonization product. S4. Integration and mechanical activation: The activated carbonized product obtained in step S3 is dry-mixed with polyethylene glycol and ball-milled to obtain a first mixture. S5. Polymer crosslinking reaction: Polyvinyl alcohol and citric acid are added to the first mixture obtained in step S4, deionized water is sprayed, and the mixture is stirred at 85℃-90℃ for 30min-60min to obtain the second mixture. S6. Shaping and Granulation: The second mixture obtained in step S5 is subjected to shaping treatment to obtain straw-derived organic calcium conditioner; In step S3, the organic acid activation solution is prepared by mixing wood vinegar condensate and humic acid in a volume ratio of 1-3:

1.

2. The straw-derived organic calcium conditioner prepared according to the method described in claim 1, characterized in that, The ingredients include the following parts by weight: 50-65 parts rice straw powder, 15-25 parts oyster shell powder, 30-50 parts organic acid activation solution, 5-15 parts polyethylene glycol, 3-8 parts polyvinyl alcohol, 1-3 parts citric acid, and 10-20 parts deionized water.

3. The straw-derived organic calcium conditioner prepared according to the method described in claim 1, characterized in that: The straw-derived organic calcium conditioner consists of regular cylindrical particles with a diameter of 4mm-10mm and a height of 3-5mm.

4. The application of the straw-derived organic calcium conditioner prepared according to the method described in claim 1 in the remediation of compacted acidic red soil, characterized in that, Includes the following steps: (a) Deep loosening operation: Use a soil loosening machine to loosen the compacted red soil, with a deep loosening depth of 30cm-40cm; (b) Application and mixing: Apply the prepared straw-derived organic calcium conditioner evenly to the surface of the deep-loosened soil at a rate of 30 kg / mu to 50 kg / mu, and mix it evenly into the soil layer of 5 cm to 20 cm with the rotary tiller. (c) Drip irrigation activation: Within 3-7 days after the completion of step (b), the first drip irrigation is carried out using an integrated water and fertilizer drip irrigation system to bring the soil moisture content to 70%-85% of the field capacity; (d) Sowing or seedling transplanting: Apply slow-release compound fertilizer before sowing or seedling transplanting, and adopt a wide and narrow row planting pattern, with a row spacing of 60cm-80cm for wide rows and 30cm-40cm for narrow rows; (e) Water and fertilizer management: Apply high-potassium water-soluble fertilizer through the integrated water and fertilizer drip irrigation system during the critical growth period of the crop.

5. The application of the straw-derived organic calcium conditioner prepared according to the method described in claim 4 in the remediation of compaction in acidic red soil, characterized in that: The soil loosening machine includes a frame, a deep loosening shovel, a soil-crushing roller, and rolling wheels. The front end of the frame includes one or more rows of deep loosening shovels. The soil-crushing roller is connected to the rear of the frame via a three-point suspension mechanism. The rolling wheels are located on both sides of the soil-crushing roller. The deep loosening shovel includes a double-winged arrow-shaped shovel tip and a shovel handle. The shovel handle of the deep loosening shovel has a backward-curved arc structure, and its end is hinged to the frame to form an adjustable tilt angle connection mechanism. The surface of the soil-crushing roller has multiple sets of soil-crushing blades spirally distributed along the circumference, and both ends of the soil-crushing roller are connected to the axle of the rolling wheels via bushings to form a linkage rotation structure.

6. The application of the straw-derived organic calcium conditioner prepared according to the method described in claim 4 in the remediation of compacted acidic red soil, characterized in that: The slow-release compound fertilizer has an N:P2O5:K2O ratio of 12:15:18, and the dosage is 15kg / mu-25kg / mu. The fertilizer should be applied at a depth of 5cm-8cm and kept 3cm-5cm away from the seedlings to prevent burning.

7. The application of the straw-derived organic calcium conditioner prepared according to the method described in claim 4 in the remediation of compacted acidic red soil, characterized in that: The high-potassium water-soluble fertilizer has an N:P2O5:K2O ratio of 10:10:

30. The amount of fertilizer applied each time is 5 kg / mu to 8 kg / mu, combined with drip irrigation.

8. The application of the straw-derived organic calcium conditioner prepared according to the method described in claim 4 in the remediation of compacted acidic red soil, characterized in that: After the seedlings are transplanted, irrigation begins when the soil moisture content is below 60% of the field water holding capacity and stops when the field water holding capacity is reached. The irrigation water source is treated by a vortex micro-nano bubble generator to generate micro-nano bubble water with a dissolved oxygen concentration maintained at 9mg / L-15mg / L.

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