A soil loosening agent, its preparation method and application

Abstract

The application relates to the technical field of soil improvement, in particular to a soil loosening agent and a preparation method and application thereof. The raw materials of the soil loosening agent include, by mass fraction, 5-10 parts of corn starch, 1-3 parts of sodium trimetaphosphate, 1-2 parts of amylase, 5-15 parts of acrylamide, 0.1-1 part of ammonium persulfate, 1-5 parts of a crosslinking agent, 1-2 parts of an emulsifier, 5-15 parts of methyl methacrylate, 1-5 parts of dopamine, 1-3 parts of a compound microbial agent, 10-20 parts of bentonite and 1-5 parts of humic acid. The application has good soil loosening effect, can promote the formation of granular structure, has excellent water retention and ventilation effects, guarantees the good growth of plant roots, makes the soil more suitable for crop growth, improves the growth and development characteristics of crops, and increases the yield and income of crops.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a soil loosening agent, its preparation method, and its application. Background Technology

[0002] Soil is an unfixed structural layer on the Earth's land surface composed of minerals, organic matter, water, air, and organisms. It possesses fertility and can support plant growth. my country has a relatively small per capita arable land area, and fertilizer application is often unscientific. The long-term unscientific use of chemical fertilizers increases soil compaction, reduces the proportion of soil porosity, and consequently lowers soil water retention capacity.

[0003] With the development of mechanized farming in my country, soil compaction in agricultural land is becoming increasingly severe, seriously affecting crop planting and growth. Compacted soil restricts root growth, causing crops to consume more nutrients than those in loosely compacted soil, thus reducing their ability to obtain nutrients.

[0004] In long-term crop production, problems such as soil compaction, high soil bulk density, and high soil compaction are very prominent, seriously restricting the healthy and sustainable development of crops. Soil compaction is an important factor affecting crop growth, significantly influencing soil bulk density, soil porosity, and soil moisture. Currently, compacted soils have poor water regulation capabilities, and are often in an anaerobic environment with low microbial activity, thus affecting soil carbon and nitrogen cycling and nutrient supply capacity, and reducing soil fertility.

[0005] To improve soil and enhance its properties, straw biochar, rice husk biochar, etc., are often added to the soil. Although this has some effect, the improvement effect is still insufficient and the duration is short.

[0006] Polyacrylamide, as a high-molecular polymer, has a good effect on improving various physical properties of soil, alleviating soil compaction, and retaining soil moisture. Therefore, it is particularly important to find a soil loosening agent that can effectively improve soil properties, reduce soil bulk density and compaction, improve soil water retention, and increase crop yield by utilizing polyacrylamide. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a soil loosening agent, its preparation method, and its application.

[0008] A soil loosening agent, the raw materials of which include, by weight: 5-10 parts corn starch, 1-3 parts sodium tripolyphosphate, 1-2 parts amylase, 5-15 parts acrylamide, 0.1-1 parts ammonium persulfate, 1-5 parts crosslinking agent, 1-2 parts emulsifier, 5-15 parts methyl methacrylate, 1-5 parts dopamine, 1-3 parts compound microbial agent, 10-20 parts bentonite, and 1-5 parts humic acid.

[0009] Preferably, the crosslinking agent is at least one of divinylbenzene and ethylene glycol dimethacrylate.

[0010] Preferably, the emulsifier is sodium dodecyl sulfate.

[0011] Preferably, the compound microbial agent includes: Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus mucilaginosus.

[0012] Preferably, the viable concentration of Bacillus subtilis is 4-6 × 10⁻⁶. 10 cfu / g, viable Bacillus amyloliquefaciens concentration of 1-3×10⁻⁶ 10 CFU / g, viable Bacillus mucilaginosus concentration is 5-9 × 10⁻⁶. 9 cfu / g.

[0013] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0014] S1. Add corn starch to sodium hydroxide solution and stir at 50-70℃ for 10-30 min. Add sodium trimetaphosphate and continue stirring for 5-15 min. Adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0015] S2. Add amylase to disodium hydrogen phosphate-citric acid buffer and stir until homogeneous to obtain enzyme solution;

[0016] S3. Add acrylamide and activated starch to water and stir evenly. Add ammonium persulfate, crosslinking agent and emulsifier and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 60-80℃ for 2-5 hours. Cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0017] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 30-40℃ for 5-10h, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 50-60℃ for 5-10h, centrifuge, wash, and vacuum dry to obtain microspheres.

[0018] S5. Add compound bacterial agent to microspheres and sonicate for 5-15 minutes. Add bentonite and humic acid, mix evenly, sieve, and granulate.

[0019] Preferably, in S1, the concentration of the sodium hydroxide solution is 1-2 mol / L.

[0020] Preferably, in S4, the ultrasonic frequency is 5-12 kHz.

[0021] Preferably, in S5, the ultrasonic frequency is 2-8 kHz.

[0022] The above-mentioned soil loosening agent is applied together with the base fertilizer, and the dosage of the soil loosening agent is 4-6 kg / mu.

[0023] This invention not only effectively loosens the soil and promotes the formation of aggregates, but also has excellent water retention and aeration effects, ensuring good root growth and making the soil more suitable for crop growth; at the same time, it can improve crop growth and development traits and increase crop yield, thus increasing production and income.

[0024] This invention utilizes cross-linked microspheres formed by combining hydrophilic acrylamide and hydrophobic methyl methacrylate. This effectively controls the water absorption and swelling of the microspheres, preventing excessive swelling. Furthermore, the addition of a starch-grafted structure, after enzymatic hydrolysis, creates a porous structure. This not only ensures high binding strength of polydopamine but also provides excellent adsorption and viscosity properties for the microorganisms, exhibiting extremely high stability. This effectively allows microorganisms to penetrate the soil, repairing soil aggregates and breaking up soil compaction. Simultaneously, the continuous growth and reproduction of microorganisms within the soil provides long-term improvement for deeply compacted soils, fundamentally improving soil compaction and creating a virtuous cycle in the soil system. Experiments have shown that this invention not only increases soil moisture content but also has a significant loosening effect on soil at a depth of 40-60 cm.

[0025] This invention loads polydopamine onto the outer layer of microsphere preforms. Polydopamine has excellent hydrophilicity and superior adhesion to soil. Combined with bentonite and humic acid, it significantly improves soil loosening and water retention, effectively promoting soil aggregate structure and altering soil porosity and bulk density. Not only does it provide excellent soil loosening, but the raw materials are also safe, green, and biodegradable, effectively increasing microbial activity to enhance the utilization of organic matter, while maintaining stable aggregate structure. Attached Figure Description

[0026] Figure 1 Comparison chart of soil bulk density at depths of 0-20cm, 20-40cm, and 40-60cm for Example 5, Comparative Example 1, Comparative Example 2, and Control Group (0-20cm, 20-40cm, and 40-60cm).

[0027] Figure 2 Comparison chart of soil moisture content at depths of 0-20cm and 20-40cm in Example 5, Comparative Example 1, Comparative Example 2, and control group;

[0028] Figure 3Comparison chart of soil compaction at depths of 0-20cm, 20-40cm, and 40-60cm for Example 5, Comparative Example 1, Comparative Example 2, and Control Group;

[0029] Figure 4 This is a comparison chart of the soluble sugar and starch content of branches from Example 5, Comparative Example 1, Comparative Example 2, and the blank group. Detailed Implementation

[0030] The present invention will be further explained below with reference to specific embodiments.

[0031] The amylase was purchased from Hebei Tuohai Biotechnology Co., Ltd., with an enzyme activity of 20,000 U / g; Bacillus subtilis was obtained from the China General Microbiological Culture Collection Center, with the number CGMCC1.821; Bacillus amyloliquefaciens was obtained from the China General Microbiological Culture Collection Center, with the number CGMCC1.857; and Bacillus mucilaginosus was obtained from the China Center for Type Culture Collection, with the number CCTCC KB 20082790.

[0032] Example 1

[0033] A soil loosening agent, the raw materials of which include: 5 kg corn starch, 1 kg sodium tripolyphosphate, 1 kg amylase, 5 kg acrylamide, 0.1 kg ammonium persulfate, 1 kg divinylbenzene, 1 kg sodium dodecyl sulfate, 5 kg methyl methacrylate, 1 kg dopamine, 1 kg compound microbial agent, 10 kg bentonite, and 1 kg humic acid.

[0034] The compound microbial agent includes: a live bacteria concentration of 4×10⁻⁶. 10 Bacillus subtilis CFU / g, viable cell concentration 1×10⁻⁶ 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 5×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0035] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0036] S1. Add corn starch to 50 kg of 1 mol / L sodium hydroxide solution, stir at 50℃ for 10 min, add sodium trimetaphosphate and continue stirring for 5 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0037] S2. Add amylase to 100kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0038] S3. Add acrylamide and activated starch to 50 kg of deionized water and stir evenly. Add ammonium persulfate, divinylbenzene and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 60℃ for 2 hours, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0039] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 30℃ for 5h, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 50℃ for 5h at a sonic frequency of 5kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0040] S5. Add compound bacterial agent to microspheres and sonicate for 5 minutes at a frequency of 2kHz. Add bentonite and humic acid, mix evenly, pass through a 90-mesh sieve, and granulate.

[0041] Example 2

[0042] A soil loosening agent, the raw materials of which include: 10 kg corn starch, 3 kg sodium tripolyphosphate, 2 kg amylase, 15 kg acrylamide, 1 kg ammonium persulfate, 5 kg divinylbenzene, 2 kg sodium dodecyl sulfate, 15 kg methyl methacrylate, 5 kg dopamine, 3 kg compound microbial agent, 20 kg bentonite, and 5 kg humic acid.

[0043] The compound microbial agent includes: a live bacteria concentration of 6×10⁻⁶. 10 Bacillus subtilis CFU / g, viable cell concentration 3×10⁻⁶ 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 9×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0044] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0045] S1. Add corn starch to 80 kg of 2 mol / L sodium hydroxide solution and stir at 70℃ for 30 min. Add sodium trimetaphosphate and continue stirring for 15 min to adjust the system to neutral. Filter, wash, and vacuum dry to obtain activated starch.

[0046] S2. Add amylase to 200 kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0047] S3. Add acrylamide and activated starch to 100 kg of deionized water and stir evenly. Add ammonium persulfate, divinylbenzene and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 80℃ for 5 h, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0048] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 40℃ for 10h, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 60℃ for 10h at a sonic frequency of 12kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0049] S5. Add compound bacterial agent to microspheres and sonicate for 15 minutes at an ultrasonic frequency of 8kHz. Add bentonite and humic acid, mix evenly, pass through a 110-mesh sieve, and granulate.

[0050] Example 3

[0051] A soil loosening agent, the raw materials of which include: 7 kg corn starch, 2.5 kg sodium trimetaphosphate, 1.2 kg amylase, 12 kg acrylamide, 0.3 kg ammonium persulfate, 4 kg ethylene glycol dimethacrylate, 1.2 kg sodium dodecyl sulfate, 12 kg methyl methacrylate, 2 kg dopamine, 2.5 kg compound microbial agent, 12 kg bentonite, and 4 kg humic acid.

[0052] The compound microbial agent includes: a live bacteria concentration of 5.5 × 10⁻⁶. 10 Bacillus subtilis with a cfu / g concentration of 1.5 × 10⁻⁶ cfu / g and a viable bacterial concentration of 1.5 × 10⁻⁶ cfu / g. 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 8×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0053] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0054] S1. Add corn starch to 60 kg of 1.5 mol / L sodium hydroxide solution, stir at 65℃ for 15 min, add sodium trimetaphosphate and continue stirring for 12 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0055] S2. Add amylase to 130 kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0056] S3. Add acrylamide and activated starch to 90 kg of deionized water and stir evenly. Add ammonium persulfate, ethylene glycol dimethacrylate and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 65°C for 4 hours, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0057] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 33℃ for 9 hours, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 52℃ for 9 hours at a sonic frequency of 6kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0058] S5. Add compound bacterial agent to microspheres and sonicate for 12 minutes at a frequency of 3 kHz. Add bentonite and humic acid, mix evenly, pass through a 100-mesh sieve, and granulate.

[0059] Example 4

[0060] A soil loosening agent, the raw materials of which include: 9 kg corn starch, 1.5 kg sodium trimetaphosphate, 1.8 kg amylase, 8 kg acrylamide, 0.7 kg ammonium persulfate, 2 kg ethylene glycol dimethacrylate, 1.8 kg sodium dodecyl sulfate, 8 kg methyl methacrylate, 4 kg dopamine, 1.5 kg compound microbial agent, 18 kg bentonite, and 2 kg humic acid.

[0061] The compound microbial agent includes: a live bacteria concentration of 4.5 × 10⁻⁶. 10 Bacillus subtilis with a cfu / g concentration of 2.5 × 10⁻⁶ cfu / g and a viable bacterial concentration of 2.5 × 10⁻⁶ cfu / g. 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 6×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0062] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0063] S1. Add corn starch to 70 kg of 1.5 mol / L sodium hydroxide solution, stir at 55℃ for 25 min, add sodium trimetaphosphate and continue stirring for 8 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0064] S2. Add amylase to 170 kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0065] S3. Add acrylamide and activated starch to 70 kg of deionized water and stir evenly. Add ammonium persulfate, ethylene glycol dimethacrylate and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 75°C for 3 hours, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0066] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 37℃ for 7 hours, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 58℃ for 7 hours at a sonic frequency of 9kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0067] S5. Add compound bacterial agent to microspheres and sonicate for 8 minutes at a frequency of 6 kHz. Add bentonite and humic acid, mix evenly, pass through a 100-mesh sieve, and granulate.

[0068] Example 5

[0069] A soil loosening agent, the raw materials of which include: 8 kg corn starch, 2 kg sodium tripolyphosphate, 1.5 kg amylase, 10 kg acrylamide, 0.5 kg ammonium persulfate, 3 kg ethylene glycol dimethacrylate, 1.5 kg sodium dodecyl sulfate, 10 kg methyl methacrylate, 3 kg dopamine, 2 kg compound microbial agent, 15 kg bentonite, and 3 kg humic acid.

[0070] The compound microbial agent includes: a live bacteria concentration of 5×10⁻⁶. 10 Bacillus subtilis CFU / g, viable cell concentration 2×10⁻⁶ 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 7×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0071] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0072] S1. Add corn starch to 65 kg of 1.5 mol / L sodium hydroxide solution, stir at 60℃ for 20 min, add sodium trimetaphosphate and continue stirring for 10 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0073] S2. Add amylase to 150kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0074] S3. Add acrylamide and activated starch to 80 kg of deionized water and stir evenly. Add ammonium persulfate, ethylene glycol dimethacrylate and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 70℃ for 3.5 h, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0075] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 35℃ for 8 hours, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 55℃ for 8 hours at a sonic frequency of 7.5kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0076] S5. Add compound bacterial agent to microspheres and sonicate for 10 minutes at an ultrasonic frequency of 4.5 kHz. Add bentonite and humic acid, mix evenly, pass through a 100-mesh sieve, and granulate.

[0077] Comparative Example 1

[0078] A soil loosening agent, the raw materials of which include: 8 kg corn starch, 2 kg sodium trimetaphosphate, 10 kg acrylamide, 0.5 kg ammonium persulfate, 3 kg ethylene glycol dimethacrylate, 1.5 kg sodium dodecyl sulfate, 10 kg methyl methacrylate, 3 kg dopamine, 2 kg compound microbial agent, 15 kg bentonite, and 3 kg humic acid.

[0079] The compound microbial agent includes: a live bacteria concentration of 5×10⁻⁶. 10 Bacillus subtilis CFU / g, viable cell concentration 2×10⁻⁶ 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 7×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0080] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0081] S1. Add corn starch to 65 kg of 1.5 mol / L sodium hydroxide solution, stir at 60℃ for 20 min, add sodium trimetaphosphate and continue stirring for 10 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0082] S2. Add acrylamide and activated starch to 80 kg of deionized water and stir evenly. Add ammonium persulfate, ethylene glycol dimethacrylate and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 70℃ for 3.5 h, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0083] S3. Add the microsphere preform to 151.5 kg of disodium hydrogen phosphate-citric acid buffer solution with pH=8-9, add dopamine, sonicate at 55℃ for 8 h at a sonic frequency of 7.5 kHz, centrifuge, wash, and vacuum dry to obtain microspheres.

[0084] S4. Add compound bacterial agent to microspheres and sonicate for 10 minutes at an ultrasonic frequency of 4.5 kHz. Add bentonite and humic acid, mix evenly, pass through a 100-mesh sieve, and granulate.

[0085] Comparative Example 2

[0086] A soil loosening agent, the raw materials of which include: 8 kg corn starch, 2 kg sodium tripolyphosphate, 1.5 kg amylase, 10 kg acrylamide, 0.5 kg ammonium persulfate, 3 kg ethylene glycol dimethacrylate, 1.5 kg sodium dodecyl sulfate, 10 kg methyl methacrylate, 2 kg compound microbial agent, 15 kg bentonite, and 3 kg humic acid.

[0087] The compound microbial agent includes: a live bacteria concentration of 5×10⁻⁶. 10 Bacillus subtilis CFU / g, viable cell concentration 2×10⁻⁶ 10 Bacillus amyloliquefaciens cfu / g, viable bacterial concentration 7×10⁻⁶ 9 CFU / g of Bacillus subtilis.

[0088] The preparation method of the above-mentioned soil loosening agent includes the following steps:

[0089] S1. Add corn starch to 65 kg of 1.5 mol / L sodium hydroxide solution, stir at 60℃ for 20 min, add sodium trimetaphosphate and continue stirring for 10 min, adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch.

[0090] S2. Add amylase to 150kg of disodium hydrogen phosphate-citric acid buffer solution with pH=6-7 and stir until homogeneous to obtain enzyme solution;

[0091] S3. Add acrylamide and activated starch to 80 kg of deionized water and stir evenly. Add ammonium persulfate, ethylene glycol dimethacrylate and sodium dodecyl sulfate and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 70℃ for 3.5 h, cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform.

[0092] S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 35℃ for 8 hours, inactivate at high temperature, centrifuge, wash, and vacuum dry to obtain microspheres.

[0093] S5. Add compound bacterial agent to microspheres and sonicate for 10 minutes at an ultrasonic frequency of 4.5 kHz. Add bentonite and humic acid, mix evenly, pass through a 100-mesh sieve, and granulate.

[0094] A comparative field experiment was conducted in a vineyard in Huailai County, Zhangjiakou City, Hebei Province. The vineyards were randomly divided into four groups: Example 5, Comparative Example 1, Comparative Example 2, and a control group. White Milk grapes were used as the experimental subject, with three replicates per plot and five vines per replicate.

[0095] In Example 5, Comparative Example 1, and Comparative Example 2, the soil loosening agents obtained in Example 5, Comparative Example 1, and Comparative Example 2, respectively, were applied to the soil together with well-rotted chicken manure. The application rate of the soil loosening agent in each group was 5 kg / mu, and the application rate of the well-rotted chicken manure was 1500 kg / mu. The control group was irrigated with clean water. All other operations in each group were carried out in accordance with conventional water and fertilizer field management.

[0096] Soil samples were taken from each group in October (after grape harvest). Soil bulk density at depths of 0-20cm, 20-40cm, and 40-60cm was determined using the ring cutter method. Soil moisture content at depths of 0-20cm and 20-40cm was determined using the alcohol combustion method. Soil compaction at depths of 20cm, 40cm, and 60cm was determined using a soil compaction meter.

[0097] like Figures 1 to 2 As shown, the soil bulk density and soil compaction of the soil in Example 5 group were consistently the lowest, while the water content was the highest, which was better than that of Comparative Examples 1-2 and the blank group (P<0.05).

[0098] After collecting grapes, each group selected the 5th node of the branch, removed the internode, dried and ground the branches, and used the anthrone colorimetric method to determine the content of soluble sugars and starches in the branches.

[0099] like Figure 4 As shown, the soluble sugar and starch content of the branches in Example 5 were the highest, which was better than that of Comparative Examples 1-2 and the blank group (P<0.05).

[0100] The applicant believes that the above results are due to the following: This invention utilizes cross-linked microspheres formed by the compounding of hydrophilic acrylamide and hydrophobic methyl methacrylate, which can effectively control the water absorption and swelling effect of the microspheres and effectively prevent excessive water absorption and swelling. In addition, the starch structure grafted into it forms a porous structure after enzymatic hydrolysis. This not only makes the binding strength of polydopamine on it high, but also has excellent adsorption and viscosity performance for the compound bacteria, and extremely high stability. This effectively ensures that the microorganisms penetrate into the soil, repair the aggregate structure, and break up soil compaction. At the same time, the microorganisms continue to grow and reproduce in the soil, which has a long-term improvement effect on deep compacted soil, fundamentally improving soil compaction and forming a virtuous cycle of the soil system. This invention loads polydopamine onto the outer layer of the microsphere preform, improving hydrophilicity and exhibiting excellent adhesion to soil. Combined with the effects of bentonite and humic acid, it significantly improves soil loosening and water retention, effectively promoting soil aggregate structure and altering soil porosity and bulk density. Not only does it provide excellent soil loosening, but the raw materials are also safe, green, and biodegradable, effectively increasing microbial activity to enhance the utilization of organic matter, while maintaining stable aggregate structure.

[0101] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A soil loosening agent, characterized in that, The raw materials, by weight, include: 5-10 parts corn starch, 1-3 parts sodium tripolyphosphate, 1-2 parts amylase, 5-15 parts acrylamide, 0.1-1 parts ammonium persulfate, 1-5 parts crosslinking agent, 1-2 parts emulsifier, 5-15 parts methyl methacrylate, 1-5 parts dopamine, 1-3 parts compound microbial agent, 10-20 parts bentonite, and 1-5 parts humic acid; The crosslinking agent is at least one of divinylbenzene and ethylene glycol dimethacrylate; The emulsifier is sodium dodecyl sulfate; The compound microbial agent includes: Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus mucilaginosus, wherein the viable concentration of Bacillus subtilis is 4 × 10⁻⁶. 10 cfu / g-6×10 10 cfu / g, viable Bacillus amyloliquefaciens concentration of 1×10⁻⁶ 10 cfu / g-3×10 10 CFU / g, viable Bacillus mucilaginosus concentration was 5 × 10⁻⁶. 9 cfu / g-9×10 9 cfu / g; The method for preparing the soil loosening agent includes the following steps: S1. Add corn starch to sodium hydroxide solution and stir at 50-70℃ for 10-30 min. Add sodium trimetaphosphate and continue stirring for 5-15 min. Adjust the system to neutral, filter, wash, and vacuum dry to obtain activated starch. S2. Add amylase to disodium hydrogen phosphate-citric acid buffer and stir until homogeneous to obtain enzyme solution; S3. Add acrylamide and activated starch to water and stir evenly. Add ammonium persulfate, crosslinking agent and emulsifier and stir evenly. While stirring, add methyl methacrylate dropwise. After the addition is complete, stir at 60-80℃ for 2-5 hours. Cool to room temperature, centrifuge, wash and vacuum dry to obtain microsphere preform. S4. Add the microsphere preform to the enzyme solution, enzymatically hydrolyze at 30-40℃ for 5-10h, inactivate at high temperature, adjust the pH of the system to 8-9, add dopamine, sonicate at 50-60℃ for 5-10h, centrifuge, wash, and vacuum dry to obtain microspheres. S5. Add compound bacterial agent to microspheres and sonicate for 5-15 minutes. Add bentonite and humic acid, mix evenly, sieve, and granulate.

2. The soil loosening agent according to claim 1, characterized in that, In S1, the concentration of sodium hydroxide solution is 1-2 mol / L.

3. The soil loosening agent according to claim 1, characterized in that, In S4, the ultrasonic frequency is 5-12kHz.

4. The soil loosening agent according to claim 1, characterized in that, In S5, the ultrasonic frequency is 2-8kHz.

5. A method for using the soil loosening agent as described in claim 1, characterized in that, The soil loosening agent is applied together with the base fertilizer at a rate of 4-6 kg / mu.

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