CN116586422B - A method for repairing contaminated soil based on earthworms and microorganisms - Google Patents

Abstract

The invention discloses a method for repairing contaminated soil based on earthworms and microorganisms, comprising the following steps: S1, earthworm cultivation; S2, microbial agent preparation; S3, soil tillage and application; S4, crop planting; S5, secondary application of microbial agent. The tillage device comprises a shell, driving wheels located on both sides of the rear of the shell, a first tillage roller located on one side of the front of the shell, and a second tillage roller located on the other side of the front of the shell. The invention applies earthworms and two microbial agents successively, so that not only can the earthworms be used to enrich, migrate and transform heavy metals, but also the nitrogen loss in the soil is reduced by adding arbuscular mycorrhizal fungi, and the applied Beauveria bassiana can kill the pest larvae in the soil. The tillage device can be used in conjunction with the method of the invention, and the application and application amount of earthworm culture soil and microbial agents can be automatically controlled, which is convenient to use.

Description

A method for repairing contaminated soil based on earthworms and microorganisms

Technical Field

The present invention relates to the technical field of soil remediation, and in particular to a method for remediating contaminated soil based on earthworms and microorganisms.

Background technique

There are many types of soil pollution, among which heavy metal pollution, soil fertility decline caused by over-cultivation, and pest and disease pollution are the main factors affecting soil functions. Soil pollution has become a major issue affecting human health and environmental safety. At present, a lot of research has been done on soil pollution remediation at home and abroad, forming several major remediation methods such as chemical remediation, physical remediation, and biological remediation (such as plant stabilization, evaporation, extraction; animal remediation; microbial remediation).

Bioremediation is the use of soil animals (such as earthworms, nematodes, arthropods, etc.) to absorb, degrade or transfer pollutants through the food chain, thereby reducing the concentration of pollutants in the soil. However, the remediation effect that can be achieved by relying solely on soil animals is very limited. Therefore, it is necessary to combine soil animals with other remediation methods to achieve better remediation purposes.

Patent CN104335729A discloses a method for soil remediation using earthworms, comprising the following steps: (1) selecting earthworm species; (2) artificially breeding earthworms; (3) placing earthworms, and placing earthworms harvested from breeding plants into soil that needs to be improved. This method is to increase the number of earthworms by artificially breeding earthworms, place the cultivated earthworms into soil that needs to be improved, and use the earthworm feces produced by earthworms during normal metabolism to achieve rapid soil improvement, which is economical, safe, and environmentally friendly. However, the remediation effect of this method is limited, and the types of soil pollution that can be applied are also relatively limited.

Summary of the invention

In view of the above-mentioned problems, the present invention provides a method for repairing contaminated soil based on earthworms and microorganisms.

The technical solution of the present invention is:

A method for remediating contaminated soil based on earthworms and microorganisms, comprising the following steps:

S1. earthworm culture: earthworm larvae are cultured in a culture medium for 15 to 20 days at a culture temperature of 22 to 25° C. The composition of the culture medium includes, by weight, 65 to 70% animal feces, 25 to 28% straw charcoal, and the remainder EM bacterial solution. After the culture is completed, a mixture of earthworms and the culture medium is obtained as earthworm culture soil, wherein the earthworm content in the earthworm culture soil is 10 to 20/kg;

S2. Preparation of microbial inoculant: placing freeze-dried powder of arbuscular mycorrhizal fungi in a culture medium for culturing for 5 to 7 days at a culture temperature of 23 to 26° C., wherein the components of the culture medium include, by weight, 75 to 80% peptone, 3 to 4% beef extract powder, 1 to 2% phosphate, and the remainder being saline, and obtaining a mixture of arbuscular mycorrhizal fungi and the culture medium after the culture is completed as an arbuscular mycorrhizal fungi culture solution, wherein the amount of viable bacteria in the arbuscular mycorrhizal fungi culture solution is 0.001 to 0.002 billion/mL;

S3. Soil tillage and application: The contaminated soil to be remediated is tilled with a tillage device. The contaminated soil is divided into several tillage rows with equal spacing. A planting row is reserved between two adjacent tillage rows. The width of the tillage row is 30-40 cm, and the width of the planting row is 50-80 cm. One tillage and two tillages are performed in a tillage row. Arbuscular mycorrhizal fungus culture solution is applied during the first tillage, and earthworm culture soil is applied during the second tillage. The depth of the first tillage and the second tillage is 20-25 cm. The application amount of arbuscular mycorrhizal fungus culture solution is 500-1000 mL/m ² , and the application amount of earthworm culture soil is 40-50 kg/m ² . After completing the first tillage and the second tillage of all tillage rows, let it stand for 45-60 days;

S4. Crop planting: Plant crops in rows inside the polluted soil after standing, with a planting density of 7 to 8 plants per ^m2 ;

S5. Secondary application of microbial agents: 30 to 90 days after crop planting, add insect-proof microbial agents to the plowed rows inside the contaminated soil. The insect-proof microbial agent is Beauveria bassiana glycerol. The amount of live bacteria in Beauveria bassiana glycerol is 0.005 to 0.01 billion/mL, and the application amount of Beauveria bassiana glycerol is 100 to 200 mL/ ^m2 .

Furthermore, the type of earthworm in step S1 is Eisenia fetida.

Description: This type of earthworm is abundant in source, low in cost, and has good effects when used.

Furthermore, in step S2, the phosphate is calcium phosphate powder, and the physiological saline is a sodium chloride solution with a mass concentration of 0.9%.

Note: Maintaining a certain osmotic pressure environment through sodium chloride and maintaining a relatively stable pH through phosphate are beneficial to microbial culture.

Furthermore, the crops planted in step S4 are one or more of Ligustrum lucidum, Euonymus japonicus, Photinia fraseri, and Pyracantha fortuneana.

Note: Planting crops can effectively improve the deep restoration of the soil, while improving the prevention and control of pests and diseases during the secondary application of microbial agents.

Furthermore, the tilling device comprises a housing, driving wheels located at both sides of the rear portion of the housing, a first tilling roller located at one side of the front portion of the housing, and a second tilling roller located at the other side of the front portion of the housing, wherein the first tilling roller and the second tilling roller are symmetrically arranged and have the same outer diameter, the bottoms of the first tilling roller and the second tilling roller are 20 to 25 cm below the driving wheels, the widths of the first tilling roller and the second tilling roller are 30 to 40 cm, and the spacing between the first tilling roller and the second tilling roller is 50 to 80 cm;

The first tilling roller is rotatably connected to the side wall of the shell through a first rotating shaft, a worm culture soil storage cylinder is fixedly connected inside the first tilling roller, a plurality of first tilling tooth groups arranged at equal intervals are provided on the outer wall of the first tilling roller, the first tilling tooth group includes a plurality of first tilling teeth arranged side by side, a first discharge port is provided on the outer wall of the first tilling roller located in the middle of two adjacent first tilling tooth groups, a second discharge port is provided on the outer wall of the earthworm culture soil storage cylinder corresponding to the position of the first discharge port, a slide groove is provided on the inner wall of the first tilling roller between the first discharge port and the second discharge port, the slide groove extends along both sides of the first discharge port, and a baffle group for blocking the first discharge port and the second discharge port is slidably connected inside the slide groove;

The second tilling roller is rotatably connected to the side wall of the shell through a second rotating shaft, a microbial agent storage cylinder is fixedly connected inside the second tilling roller, a plurality of second tilling tooth groups arranged at equal intervals are provided on the outer wall of the second tilling roller, the second tilling tooth group includes a plurality of second tilling teeth arranged side by side, and a feed pipe is provided inside each first tilling tooth of one group of second tilling teeth, the bottom of the feed pipe extends to the outside of the bottom of the second tilling tooth, the top of the feed pipe is connected to an elastic water bag located between the second tilling roller and the microbial agent storage cylinder, and the elastic water bag is connected to the microbial agent storage cylinder.

Furthermore, an auxiliary wheel is provided at the front end of the shell, the bottom of the auxiliary wheel is flush with the bottom of the driving wheel, the driving wheel is driven to rotate by a driving motor located inside the shell, and a handle is provided on the top of the shell.

Note: The auxiliary wheels are used to stabilize the balance of the device.

Furthermore, the width of the second tilling teeth is twice that of the first tilling teeth, and the spacing between each set of the second tilling teeth is twice that of the spacing between each set of the first tilling teeth.

Description: By limiting the width of the two tilling teeth, double tillage can be achieved. The first tillage is relatively rough tillage through the second tilling teeth, coordinated with the release of microbial agents, while the second tillage is fine tillage through the first tilling teeth, which is conducive to the uniform application of earthworm culture soil containing earthworms on the surface of the contaminated soil.

Furthermore, the baffle group includes a weighted block and a baffle plate slidably connected to the slide slot, the weighted block and the baffle plate are fixedly connected by an arc-shaped fixing rod, and limit grooves for limiting the weighted block are provided on both sides of the slide slot, and limit blocks slidably connected to the limit grooves are provided on both sides of the weighted block. When the weighted block slides down to the position of the front end of the limit groove under the action of gravity, the weighted block pushes the baffle plate to slide to the front end of the first and second feeding ports through the arc-shaped fixing rod, thereby opening the first and second feeding ports. When the weighted block slides down to the position of the rear end of the limit groove under the action of gravity, the weighted block pulls the baffle plate to slide to the position between the first and second feeding ports through the arc-shaped fixing rod, thereby blocking the first and second feeding ports.

Description: Through the setting of the baffle group, during the plowing process of the first tilling roller, under the action of gravity, the baffle plate can be driven to alternately seal and open the two feed ports, thereby controlling the discharge amount of earthworm culture soil. At the same time, the earthworms in the earthworm culture soil will not be damaged when opening and closing, thereby achieving the purpose of automatic control and being convenient for staff to use.

Furthermore, a group of second tilling tooth groups at the front section of the second tilling tooth group provided with the discharge pipe is a telescopic tilling tooth group, and the second tilling teeth of the telescopic tilling tooth group include an upper telescopic rod and a lower telescopic rod which are slidably connected, and the top of each lower telescopic rod passes through the second tilling roller and is fixedly connected to a push plate located between the second tilling roller and the microbial agent storage cylinder, and the push plate is located below the elastic water bag and is inclined to the rear side. When the lower telescopic rod is squeezed, the push plate squeezes the elastic water bag so that the microbial agent inside it is discharged through the discharge pipe, and a liquid inlet is provided on the outer wall of the second tilling roller on the side opposite to the telescopic tilling tooth group.

Description: Through the setting of the feed pipe and the retractable tillage tooth group, the discharge of the microbial agent can be realized and the discharge amount of the microbial agent can be controlled. Similarly, it is easy to use and automatically controlled, which improves work efficiency.

The beneficial effects of the present invention are:

(1) The method of the present invention for remediating contaminated soil based on earthworms and microorganisms is to apply earthworms and two microbial agents in sequence, which not only can achieve the enrichment, migration and transformation of heavy metals through earthworms, but also reduce the nitrogen loss in the soil by adding arbuscular mycorrhizal fungi, reduce the nitrogen loss caused by earthworms, and maintain soil fertility. After applying arbuscular mycorrhizal fungi, crops are planted, and then the microbial agents are applied for the second time. The applied Beauveria bassiana can kill the larvae of pests in the soil, effectively controlling the diseases and insect pests in the contaminated soil, and the Beauveria bassiana attached to the surface of the earthworms can improve the killing effect on pests.

(2) The method of the present invention for remediating contaminated soil based on earthworms and microorganisms also optimizes the width of the tillage rows and planting rows and the tillage depth, so as to better achieve the application of earthworms and microbial agents. The unique tillage device of the present invention can be used in conjunction with the method of the present invention, and the application and application amount of earthworm culture soil and microbial agents can be automatically controlled, which is easy to use.

(3) In a method for repairing contaminated soil based on earthworms and microorganisms of the present invention, the tilling device limits the width of two tilling teeth to achieve the degree of double tillage. The first tillage is relatively rough tillage by the second tilling teeth, coordinated with the release of microbial agents, and the second tillage is fine tillage by the first tilling teeth, which is conducive to the uniform application of earthworm culture soil containing earthworms on the surface of the contaminated soil; the setting of the baffle group can make it possible to drive the baffle plate to alternately seal and open the two feed ports during the tillage process of the first tilling roller under the action of gravity, so as to control the discharge amount of earthworm culture soil, and at the same time, the earthworms in the earthworm culture soil will not be damaged when opening and closing, so as to achieve the purpose of automatic control and facilitate the use of staff; the setting of the feed pipe in coordination with the retractable tilling tooth group can realize the discharge of microbial agents and control the discharge amount of microbial agents. Similarly, it is easy to use and automatically controlled, thereby improving work efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a process flow chart of a method for remediating contaminated soil based on earthworms and microorganisms of the present invention;

FIG2 is a schematic diagram of the structure of a tillage device in a method for remediating contaminated soil based on earthworms and microorganisms according to the present invention;

FIG3 is a top view of a tillage device in a method for remediating contaminated soil based on earthworms and microorganisms of the present invention;

FIG4 is a schematic diagram of the internal structure of the first tillage drum in a method for remediating contaminated soil based on earthworms and microorganisms of the present invention;

5 is a cross-sectional view of the internal structure of the first tillage drum when the baffle group closes two feed openings in a method for remediating contaminated soil based on earthworms and microorganisms of the present invention;

6 is a cross-sectional view of the internal structure of the first tillage drum when the baffle plate group opens two feed openings in a method for remediating contaminated soil based on earthworms and microorganisms of the present invention;

7 is a cross-sectional view of the internal structure of the second tillage drum in a method for remediating contaminated soil based on earthworms and microorganisms of the present invention.

Among them, 1-shell, 11-auxiliary wheel, 12-drive motor, 13-handle, 2-drive wheel, 3-first tilling roller, 31-first rotating shaft, 32-earthworm culture soil storage cylinder, 33-first tilling tooth group, 331-first tilling tooth, 34-first discharge port, 35-second discharge port, 36-chute, 37-limiting groove, 4-second tilling roller, 41-second rotating shaft, 42-microorganism inoculant storage cylinder, 43-second tilling tooth group, 431-second tilling tooth, 44-discharge pipe, 45-elastic water bag, 46-liquid inlet, 5-baffle group, 51-weight block, 52-shielding plate, 53-arc-shaped fixed rod, 54-limiting block, 6-retractable tilling tooth group, 61-upper telescopic rod, 62-lower telescopic rod, 63-push plate.

Detailed ways

Example 1

A method for remediating contaminated soil based on earthworms and microorganisms, as shown in FIG1 , comprises the following steps:

S1. earthworm culture: earthworm larvae are cultured in a culture medium for 18 days at a culture temperature of 23° C. The composition of the culture medium includes, by weight, 67% animal feces, 26% straw charcoal, and the remainder EM bacterial solution. After the culture is completed, a mixture of earthworms and the culture medium is obtained as earthworm culture soil. The earthworm content in the earthworm culture soil is 15/kg, and the earthworm species is Eisenia fetida.

S2. Preparation of microbial inoculants: freeze-dried powder of arbuscular mycorrhizal fungi was placed in a culture medium for 6 days at a culture temperature of 25° C. The components of the culture medium included, by weight, 78% peptone, 3.5% beef extract powder, 1.5% calcium phosphate powder, and the remainder normal saline, wherein the normal saline was a sodium chloride solution with a mass concentration of 0.9%. After the culture was completed, a mixture of arbuscular mycorrhizal fungi and the culture medium was obtained as an arbuscular mycorrhizal fungi culture solution, and the amount of viable bacteria in the arbuscular mycorrhizal fungi culture solution was 0.0015 million/mL;

S3. Soil tillage and application: The contaminated soil to be remediated is tilled with a tillage device. The contaminated soil is divided into several tillage rows with equal spacing. A planting row is reserved between two adjacent tillage rows. The width of the tillage row is 35 cm, and the width of the planting row is 70 cm. One tillage and two tillages are performed in a tillage row. Arbuscular mycorrhizal fungus culture solution is applied during the first tillage, and earthworm culture soil is applied during the second tillage. The depth of the first tillage and the second tillage is 23 cm. The application amount of the arbuscular mycorrhizal fungus culture solution is 800 mL/m ² , and the application amount of the earthworm culture soil is 45 kg/m ² . After completing the first tillage and the second tillage of all tillage rows, let it stand for 50 days;

The tillage device adopts a commercially available tillage device;

S4. Crop planting: Plant crops in the planting rows inside the polluted soil after standing, with a planting density of 7 plants per square ^meter . The crops planted are Ligustrum lucidum and Euonymus japonicus.

S5. Secondary application of microbial agents: 60 days after crop planting, add insect-proof microbial agents to the contaminated soil. The insect-proof microbial agent is Beauveria bassiana glycerol. The amount of live bacteria in Beauveria bassiana glycerol is 0.0075 billion/mL, and the application amount of Beauveria bassiana glycerol is 150mL/ ^m2 . Arbuscular mycorrhizal fungi freeze-dried powder and Beauveria bassiana glycerol are both commercially available products.

Example 2

The difference between this embodiment and embodiment 1 is that the parameter selection in step S1 is different.

S1. Earthworm culture: earthworm larvae are cultured in a culture medium for 15 days at a temperature of 22°C. The components of the culture medium are, by weight, 65% animal feces, 25% straw charcoal, and the remainder EM bacterial solution. After the culture is completed, a mixture of earthworms and the culture medium is obtained as earthworm culture soil. The earthworm content in the earthworm culture soil is 10 worms/kg, and the earthworm species is Eisenia fetida.

Example 3

The difference between this embodiment and embodiment 1 is that the parameter selection in step S1 is different.

S1. Earthworm culture: earthworm larvae are cultured in a culture medium for 20 days at a temperature of 25°C. The components of the culture medium include, by weight, 70% animal feces, 28% straw charcoal, and the remainder EM bacterial solution. After the culture is completed, a mixture of earthworms and culture medium is obtained as earthworm culture soil. The earthworm content in the earthworm culture soil is 20 worms/kg, and the earthworm species is Eisenia fetida.

Example 4

The difference between this embodiment and embodiment 1 is that the parameter selection in step S2 is different.

S2. Preparation of microbial inoculants: The freeze-dried powder of arbuscular mycorrhizal fungi was placed in a culture medium for cultivation for 5 days at a temperature of 23°C. The components of the culture medium included, by weight, 75% peptone, 3% beef extract powder, 1% calcium phosphate powder, and the remainder normal saline, wherein the normal saline was a sodium chloride solution with a mass concentration of 0.9%. After the cultivation, a mixture of arbuscular mycorrhizal fungi and the culture medium was obtained as an arbuscular mycorrhizal fungi culture solution, and the amount of viable bacteria in the arbuscular mycorrhizal fungi culture solution was 0.001 billion/mL.

Example 5

The difference between this embodiment and embodiment 1 is that the parameter selection in step S2 is different.

S2. Preparation of microbial inoculants: The freeze-dried powder of arbuscular mycorrhizal fungi was placed in a culture medium for culturing for 7 days at a temperature of 26°C. The components of the culture medium included, by weight, 80% peptone, 4% beef extract powder, 2% calcium phosphate powder, and the remainder normal saline, wherein the normal saline was a sodium chloride solution with a mass concentration of 0.9%. After the culturing, a mixture of arbuscular mycorrhizal fungi and the culture medium was obtained as an arbuscular mycorrhizal fungi culture solution, and the amount of live bacteria in the arbuscular mycorrhizal fungi culture solution was 0.002 million/mL.

Example 6

The difference between this embodiment and embodiment 1 is that the parameter selection in step S3 is different.

S3. Soil tillage and application: The contaminated soil to be remediated is tilled with a tillage device. The contaminated soil is divided into several tillage rows with equal spacing. A planting row is reserved between two adjacent tillage rows. The width of the tillage row is 30 cm, and the width of the planting row is 50 cm. One tillage and two tillages are carried out in succession in one tillage row. During the first tillage, arbuscular mycorrhizal fungus culture solution is applied, and during the second tillage, earthworm culture soil is applied. The depth of the first tillage and the second tillage is 20 cm. The application amount of arbuscular mycorrhizal fungus culture solution is 500 mL/ ^m2 , and the application amount of earthworm culture soil is 40 kg/ ^m2 . After completing the first tillage and the second tillage of all tillage rows, let it stand for 45 days.

Example 7

The difference between this embodiment and embodiment 1 is that the parameter selection in step S3 is different.

S3. Soil tillage and application: The contaminated soil to be remediated is tilled with a tillage device. The contaminated soil is divided into several tillage rows with equal spacing. A planting row is reserved between two adjacent tillage rows. The width of the tillage row is 40 cm, and the width of the planting row is 80 cm. One tillage and two tillages are carried out in succession in one tillage row. Arbuscular mycorrhizal fungus culture solution is applied during the first tillage, and earthworm culture soil is applied during the second tillage. The depth of the first tillage and the second tillage is 25 cm. The application amount of the arbuscular mycorrhizal fungus culture solution is 1000 mL/ ^m2 , and the application amount of the earthworm culture soil is 50 kg/ ^m2 . After completing the first tillage and the second tillage of all tillage rows, let it stand for 60 days.

Example 8

The difference between this embodiment and embodiment 1 is that the parameter selection in steps S4 and S5 is different.

S4. Crop planting: Planting crops in the rows inside the polluted soil after standing, with a planting density of 8 plants per m ² , and the crop planted is Photinia;

S5. Secondary application of microbial agents: 30 days after crop planting, add insect-proof microbial agents to the plowed rows inside the contaminated soil. The insect-proof microbial agent is Beauveria bassiana glycerol. The amount of live bacteria in Beauveria bassiana glycerol is 0.005 billion/mL, and the application amount of Beauveria bassiana glycerol is 100mL/ ^m2 .

Example 9

The difference between this embodiment and embodiment 1 is that the parameter selection in steps S4 and S5 is different.

S4. Crop planting: Plant crops in the planting rows inside the contaminated soil after standing, with a planting density of 8 plants per m ² , and the crop planted is Pyracantha;

S5. Secondary application of microbial agents: 90 days after crop planting, add insect-proof microbial agents to the plowed rows inside the contaminated soil. The insect-proof microbial agent is Beauveria bassiana glycerol. The amount of live bacteria in Beauveria bassiana glycerol is 100 million/mL. The application amount of Beauveria bassiana glycerol is 200mL/ ^m2 .

Example 10

As shown in Figures 2 and 3, this embodiment is a further optimization of the tilling device in Example 1. The tilling device includes a shell 1, driving wheels 2 located on both sides of the rear part of the shell 1, a first tilling roller 3 located on one side of the front part of the shell 1, and a second tilling roller 4 located on the other side of the front part of the shell 1. The first tilling roller 3 and the second tilling roller 4 are symmetrically arranged and have the same outer diameter. The bottom of the first tilling roller 3 and the second tilling roller 4 is 26 cm below the driving wheel 2. The width of the first tilling roller 3 and the second tilling roller 4 is 35 cm. The spacing between the first tilling roller 3 and the second tilling roller 4 is 70 cm. An auxiliary wheel 11 is provided at the front end of the shell 1. The bottom of the auxiliary wheel 11 is flush with the bottom of the driving wheel 2. The driving wheel 2 is driven to rotate by a driving motor 12 located inside the shell 1. The driving motor 12 is a commercially available driving motor for agricultural implements. A handle 13 is provided on the top of the shell 1.

As shown in Figures 3 and 4, the first tilling roller 3 is rotatably connected to the side wall of the shell 1 through a first rotating shaft 31, a worm culture soil storage cylinder 32 is fixedly connected inside the first tilling roller 3, a plurality of first tilling tooth groups 33 arranged at equal intervals are provided on the outer wall of the first tilling roller 3, the first tilling tooth group 33 includes a plurality of first tilling teeth 331 arranged side by side, a first discharge port 34 is provided on the outer wall of the first tilling roller 3 located in the middle of two adjacent first tilling tooth groups 33, a second discharge port 35 is provided on the outer wall of the earthworm culture soil storage cylinder 32 corresponding to the position of the first discharge port 34, a slide groove 36 is provided on the inner wall of the first tilling roller 3 between the first discharge port 34 and the second discharge port 35, the slide groove 36 extends along both sides of the first discharge port 34, and a baffle group 5 for blocking the first discharge port 34 and the second discharge port 35 is slidably connected inside the slide groove 36;

As shown in Figures 2 and 7, the second tilling roller 4 is rotatably connected to the side wall of the shell 1 through a second rotating shaft 41, a microbial agent storage cylinder 42 is fixedly connected inside the second tilling roller 4, and a plurality of second tilling tooth groups 43 arranged at equal intervals are provided on the outer wall of the second tilling roller 4. The second tilling tooth groups 43 include a plurality of second tilling teeth 431 arranged side by side, and each first tilling tooth 331 of a group of second tilling tooth groups 43 is provided with a feed pipe 44 inside, and the bottom of the feed pipe 44 extends to the outside of the bottom of the second tilling tooth 431, and the top of the feed pipe 44 is connected to an elastic water bag 45 located between the second tilling roller 4 and the microbial agent storage cylinder 42, and the elastic water bag 45 is connected to the microbial agent storage cylinder 42, and the width of the second tilling tooth 431 is twice that of the first tilling tooth 331, and the spacing between each second tilling tooth group 43 is twice that between each first tilling tooth group 33;

As shown in FIGS. 4 to 6, the baffle plate group 5 includes a weighted block 51 and a shielding plate 52 slidably connected to the slide groove 36, and the weighted block 51 and the shielding plate 52 are fixedly connected by an arc-shaped fixing rod 53. The slide groove 36 has limiting grooves 37 on both sides for limiting the weighted block 51, and limiting blocks 54 slidably connected to the limiting grooves 37 are provided on both sides of the weighted block 51. When the weighted block 51 slides down to the position where the front end of the limiting groove 37 is located under the action of gravity, the weighted block 51 pushes the shielding plate 52 to slide to the front end of the first and second discharge openings 34 and 35 through the arc-shaped fixing rod 53, thereby opening the first and second discharge openings 34 and 35. When the weighted block 51 slides down to the position where the rear end of the limiting groove 37 is located under the action of gravity, the weighted block 51 pulls the shielding plate 52 to slide to the position between the first and second discharge openings 34 and 35 through the arc-shaped fixing rod 53, thereby blocking the first and second discharge openings 34 and 35.

As shown in Figures 2 and 7, a group of second tilling tooth groups 43 at the front section of the second tilling tooth group 43 provided with a discharge pipe 44 is a telescopic tilling tooth group 6. The second tilling tooth 431 of the telescopic tilling tooth group 6 includes an upper telescopic rod 61 and a lower telescopic rod 62 that are slidably connected. The top of each lower telescopic rod 62 passes through the second tilling roller 4 and is fixedly connected to a push plate 63 located between the second tilling roller 4 and the microbial agent storage cylinder 42. The push plate 63 is located below the elastic water bag 45 and the push plate 63 is tilted to the rear. When the lower telescopic rod 62 is squeezed, the push plate 63 squeezes the elastic water bag 45 so that the microbial agent inside it is discharged through the discharge pipe 44. A liquid inlet 46 is provided on the outer wall of the second tilling roller 4 on the side opposite to the telescopic tilling tooth group 6.

working principle:

When using the tilling device of the present invention, firstly, the second tilling roller 4 is placed on the first tilling row, and the arbuscular mycorrhizal fungi culture solution is injected into the microbial agent storage cylinder 42 through the liquid inlet 46. The earthworm culture soil storage cylinder 32 of the first tilling roller 3 is not filled with earthworm culture soil first, and the driving motor 12 is turned on to drive the driving wheel 2 to rotate and drive the shell 1 to move. Note that the moving speed should not be too fast, and it is best to control it within 5-6 m/min. When the shell 1 moves, the second tilling roller 4 is driven to rotate, and the first tilling row of the contaminated soil is tilled through the second tilling tooth group 43. At the same time, whenever the telescopic tilling tooth group 6 rotates to contact the inside of the soil, the lower telescopic rod 62 is squeezed to push the push plate 63, thereby squeezing the elastic water bag 45, so that the arbuscular mycorrhizal fungi culture solution inside is discharged into the contaminated soil through the discharge pipe 44 along the end of the second tilling tooth 431, so that the "arbuscular mycorrhizal fungi culture solution is applied while tilling once" in step S3 can be achieved;

When the plowing of the first plowing row is completed, the plowing device is reset and moved horizontally for a distance so that the first plowing roller 3 is located on the first plowing row, and the second plowing roller 4 is located on the next plowing row. The driving motor 12 can be turned on again to start the plowing of the next plowing row. At the same time, the first plowing roller 3 starts to plow the first plowing row for the second time. Before starting, earthworm culture soil is poured into the earthworm culture soil storage tube 32. When the shell 1 moves, the first plowing roller 3 is driven to rotate, and the first plowing row of contaminated soil is plowed for the second time through the first plowing teeth 3. At the same time, whenever the baffle group 5 rotates to the state shown in Figure 6, the weight block 51 slides along the slide groove 36 under the action of gravity until the limit block 54 contacts one end of the limit groove 37. At this time, the arc solid The fixed rod 52 corresponds to between the first discharge port 34 and the second discharge port 35, so that the two discharge ports are connected and connected to the outside world, so that the earthworm culture soil can be discharged into the contaminated soil through the two discharge ports. When the first tilling roller 3 continues to rotate to the state shown in Figure 5, the weight block 51 slides along the slide groove 36 under the action of gravity until the limit block 54 contacts the other end of the limit groove 37. The baffle plate 52 corresponds to between the first discharge port 34 and the second discharge port 35, so that the two discharge ports are blocked and sealed to prevent the earthworm culture soil from continuing to be discharged, thereby achieving the purpose of controlling the discharge amount of the earthworm culture soil and realizing step S3 of "performing one tillage and two tillages in succession in one tillage row, applying arbuscular mycorrhizal fungal culture solution while plowing once, and applying earthworm culture soil while plowing twice".

After steps S4 and S5 are completed, the planted crops can be transplanted to other places where they are needed, so that the treated soil can achieve the purpose of farming and achieve certain economic benefits.

Claims (8)

1. A method for remediating contaminated soil based on earthworms and microorganisms, characterized in that it comprises the following steps: S1. earthworm culture: earthworm larvae are cultured in a culture medium for 15 to 20 days at a culture temperature of 22 to 25° C. The composition of the culture medium includes, by weight, 65 to 70% animal feces, 25 to 28% straw charcoal, and the remainder EM bacterial solution. After the culture is completed, a mixture of earthworms and the culture medium is obtained as earthworm culture soil, wherein the earthworm content in the earthworm culture soil is 10 to 20/kg; S2. Preparation of microbial inoculant: placing freeze-dried powder of arbuscular mycorrhizal fungi in a culture medium for culturing for 5 to 7 days at a culture temperature of 23 to 26° C., wherein the components of the culture medium include, by weight, 75 to 80% peptone, 3 to 4% beef extract powder, 1 to 2% phosphate, and the remainder being saline, and obtaining a mixture of arbuscular mycorrhizal fungi and the culture medium after the culture is completed as an arbuscular mycorrhizal fungi culture solution, wherein the amount of viable bacteria in the arbuscular mycorrhizal fungi culture solution is 0.001 to 0.002 billion/mL; S3. Soil tillage and application: The contaminated soil to be remediated is tilled with a tillage device. The contaminated soil is divided into several tillage rows with equal spacing. A planting row is reserved between two adjacent tillage rows. The width of the tillage row is 30-40 cm, and the width of the planting row is 50-80 cm. One tillage and two tillages are performed in a tillage row. Arbuscular mycorrhizal fungus culture solution is applied during the first tillage, and earthworm culture soil is applied during the second tillage. The depth of the first tillage and the second tillage is 20-25 cm. The application amount of arbuscular mycorrhizal fungus culture solution is 500-1000 mL/m ² , and the application amount of earthworm culture soil is 40-50 kg/m ² . After completing the first tillage and the second tillage of all tillage rows, let it stand for 45-60 days; S4. Crop planting: Plant crops in rows inside the polluted soil after standing, with a planting density of 7 to 8 plants per ^m2 ; S5. Secondary application of microbial agents: 30 to 90 days after crop planting, add insect-proof microbial agents to the contaminated soil during tillage. The insect-proof microbial agent is Beauveria bassiana glycerol. The amount of live bacteria in Beauveria bassiana glycerol is 0.005 to 0.01 billion per mL. The application amount of Beauveria bassiana glycerol is 100 to 200 mL/ ^m2. The tilling device comprises a housing (1), driving wheels (2) located at both sides of the rear of the housing (1), a first tilling roller (3) located at one side of the front of the housing (1), and a second tilling roller (4) located at the other side of the front of the housing (1), wherein the first tilling roller (3) and the second tilling roller (4) are symmetrically arranged and have the same outer diameter, the bottom of the first tilling roller (3) and the second tilling roller (4) are 20 to 25 cm below the driving wheel (2), the width of the first tilling roller (3) and the second tilling roller (4) is 30 to 40 cm, and the spacing between the first tilling roller (3) and the second tilling roller (4) is 50 to 80 cm; The first tilling roller (3) is rotatably connected to the side wall of the shell (1) via a first rotating shaft (31); an earthworm culture soil storage cylinder (32) is fixedly connected inside the first tilling roller (3); a plurality of first tilling tooth groups (33) arranged at equal intervals are provided on the outer wall of the first tilling roller (3); the first tilling tooth group (33) comprises a plurality of first tilling teeth (331) arranged side by side; the outer wall of the first tilling roller (3) located in the middle of two adjacent first tilling tooth groups (33) is provided with a first tilling tooth group (331); A feeding port (34), a second feeding port (35) is provided on the outer wall of the earthworm culture soil storage cylinder (32) corresponding to the position of the first feeding port (34), a slide groove (36) is provided on the inner wall of the first tillage roller (3) between the first feeding port (34) and the second feeding port (35), the slide groove (36) extends along both sides of the first feeding port (34), and a baffle plate group (5) for blocking the first feeding port (34) and the second feeding port (35) is slidably connected inside the slide groove (36); The second tilling roller (4) is rotatably connected to the side wall of the shell (1) via a second rotating shaft (41); a microbial agent storage cylinder (42) is fixedly connected inside the second tilling roller (4); a plurality of second tilling tooth groups (43) arranged at equal intervals are provided on the outer wall of the second tilling roller (4); the second tilling tooth groups (43) include a plurality of second tilling teeth (431) arranged side by side; a feed pipe (44) is provided inside each first tilling tooth (331) of a group of second tilling tooth groups (43); the bottom of the feed pipe (44) extends to the outside of the bottom of the second tilling tooth (431); the top of the feed pipe (44) is connected to an elastic water bag (45) located between the second tilling roller (4) and the microbial agent storage cylinder (42); and the elastic water bag (45) is connected to the microbial agent storage cylinder (42). 2. A method for remediating contaminated soil based on earthworms and microorganisms according to claim 1, characterized in that the type of earthworms in step S1 is Eisenia fetida. 3. A method for remediating contaminated soil based on earthworms and microorganisms according to claim 1, characterized in that the phosphate in step S2 is calcium phosphate powder, and the physiological saline is a sodium chloride solution with a mass concentration of 0.9%. 4. A method for remediating contaminated soil based on earthworms and microorganisms according to claim 1, characterized in that the crops planted in step S4 are one or more of Ligustrum lucidum, Euonymus japonicus, Photinia fraseri, and Pyracantha fortuneana. 5. According to claim 1, a method for remediating contaminated soil based on earthworms and microorganisms is characterized in that an auxiliary wheel (11) is provided at the front end of the shell (1), the bottom of the auxiliary wheel (11) is flush with the bottom of the driving wheel (2), the driving wheel (2) is driven to rotate by a driving motor (12) located inside the shell (1), and a handle (13) is provided on the top of the shell (1). 6. According to a method for remediating contaminated soil based on earthworms and microorganisms as described in claim 1, it is characterized in that the width of the second tilling teeth (431) is twice that of the first tilling teeth (331), and the spacing between each of the second tilling tooth groups (43) is twice the spacing between each of the first tilling tooth groups (33). 7. A method for remediating contaminated soil based on earthworms and microorganisms according to claim 1, characterized in that the baffle group (5) includes a weight block (51) and a shielding plate (52) slidably connected to the slide groove (36), the weight block (51) and the shielding plate (52) are fixedly connected by an arc-shaped fixing rod (53), and the slide groove (36) is provided with limiting grooves (37) on both sides thereof for limiting the weight block (51), and limiting blocks (54) slidably connected to the limiting grooves (37) are provided on both sides of the weight block (51), when the weight block (51) slides down to the limiting groove (37) under the action of gravity, the weight block (51) is fixedly connected to the limiting groove (37) by an arc-shaped fixing rod (53). 7) When the front end is at the position, the weight block (51) pushes the shielding plate (52) to slide to the front end of the first discharge port (34) and the second discharge port (35) through the arc-shaped fixing rod (53), thereby opening the first discharge port (34) and the second discharge port (35); when the weight block (51) slides down to the position of the rear end of the limiting groove (37) under the action of gravity, the weight block (51) pulls the shielding plate (52) to slide to the position between the first discharge port (34) and the second discharge port (35) through the arc-shaped fixing rod (53), thereby blocking the first discharge port (34) and the second discharge port (35). 8. A method for repairing contaminated soil based on earthworms and microorganisms according to claim 1, characterized in that a group of second tilling tooth groups (43) at the front section of the second tilling tooth group (43) provided with the discharge pipe (44) is a telescopic tilling tooth group (6), and the second tilling teeth (431) of the telescopic tilling tooth group (6) include an upper telescopic rod (61) and a lower telescopic rod (62) that are slidably connected, and the top of each lower telescopic rod (62) passes through the second tilling roller (4) and is fixedly connected to a push plate (63) located between the second tilling roller (4) and the microbial agent storage cylinder (42), and the push plate (63) is located below the elastic water bag (45) and the push plate (63) is tilted to the rear side, and when the lower telescopic rod (62) is squeezed, the push plate (63) squeezes the elastic water bag (45) so that the microbial agent inside it is discharged through the discharge pipe (44), and a liquid inlet (46) is provided on the outer wall of the second tilling roller (4) on the side opposite to the telescopic tilling tooth group (6).