Soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system and application method

Abstract

The invention belongs to the technical field of environmental remediation, and particularly relates to a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system and an application method, and the soil remediation composition comprises the arbuscular mycorrhizal fungi and the ecological support system. The arbuscular mycorrhizal fungi, i.e., the heteromorpha rhizopus, comprise the heteromorpha rhizopus; the ecological supporting system comprises hydroxyapatite and biochar, so that the bioavailability of cadmium and arsenic in soil can be reduced, and healthy growth of plants is promoted. Through innovative combination and application technologies, an efficient and environment-friendly heavy metal contaminated soil remediation solution is provided, the remediation effect and plant growth performance are remarkably improved, and powerful support is provided for agricultural safety production and environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental restoration, and in particular to a soil restoration composition based on arbuscular mycorrhizal fungi and an ecological support system and an application method thereof. Background Art

[0002] With the development of industrialization and agriculture, the problem of heavy metal pollution in soil is becoming increasingly serious, especially the combined pollution of cadmium (Cd) and arsenic (As), which has become a major problem threatening food security and human health. Existing soil remediation technologies such as chemical passivation, plant extraction and microbial remediation, although each has its own advantages, show obvious limitations in dealing with combined pollution of cadmium and arsenic, such as unstable remediation effects, potential secondary pollution and limited application scope.

[0003] Arbuscular mycorrhizal fungi (AMF) are a class of beneficial microorganisms that can form a symbiotic relationship with plant roots. They have been widely studied and proven to have significant effects in improving plant nutrient absorption and stress resistance. In addition, the potential of AMF in the remediation of heavy metal-contaminated soils has gradually been recognized. However, the remediation efficiency of AMF remediation technology alone is often not ideal when faced with high pollution or adverse environmental conditions. At the same time, key components in the ecological support system, such as hydroxyapatite (HAP) and biochar (BC), have shown excellent performance in reducing the bioavailability of heavy metals in soil. Therefore, combining AMF with the ecological support system to form a comprehensive remediation strategy has important research and application value in the remediation of cadmium and arsenic co-contaminated soils.

[0004] In practical applications, how to accurately and evenly apply arbuscular mycorrhizal fungi and ecological support systems to contaminated soil has become a key issue in achieving the best remediation effect. Traditional application methods have many limitations, such as uneven application, imprecise dosage control, and complex operations. These problems may lead to uneven inoculation of mycorrhizal fungi and unsatisfactory distribution of ecological support systems in the soil, thus affecting the passivation effect of heavy metals and plant growth.

[0005] In addition, the demand for application equipment in the field of modern agriculture and environmental remediation is growing, especially in the treatment of large-scale soil pollution. High-efficiency application equipment that can significantly improve the remediation efficiency has attracted much attention. Although existing application equipment is mainly used for the application of fertilizers and pesticides, these devices often cannot meet special needs when applying microorganisms and ecological support systems, such as accurately controlling the application amount, ensuring the uniform mixing and application of multiple substances, and adapting to complex field environments. Therefore, the invention of a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system and an application method can effectively solve the deficiencies in the prior art and ensure the uniform distribution and efficient application of remediation materials in contaminated soil, thereby achieving better remediation effects. Summary of the invention

[0006] In view of the above and / or existing problems in a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system and an application method, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to provide a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system and an application method, which can solve the above-mentioned existing problems.

[0008] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0009] A soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system, comprising arbuscular mycorrhizal fungi Heterosporium heterorhizogenes and an ecological support system;

[0010] The arbuscular mycorrhizal fungus Heteromorpha includes Heteromorpha;

[0011] The ecological support system includes hydroxyapatite and biochar, so as to reduce the bioavailability of cadmium and arsenic in the soil and promote the healthy growth of plants.

[0012] As a preferred embodiment of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the inoculant of Heteromorpha rhizosporum is a mixture of host plant root segments, mycorrhizal fungal spores and extraradical mycelium, and its spore density is 50 to 90 spores / g.

[0013] As a preferred solution of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the addition amount of hydroxyapatite is 0.5-2% of the soil mass.

[0014] As a preferred embodiment of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the addition amount of the biochar is 0.5-3% of the soil mass, and it is formed by high-temperature pyrolysis of straw biomass, and the pH value is 8.5-9.

[0015] A method for applying a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system comprises the following specific steps:

[0016] Step 1: applying the composition to the farmland soil contaminated with cadmium and arsenic by using an application device;

[0017] Step 2: Mix the soil and the composition thoroughly, and add water as needed to maintain soil moisture;

[0018] Step 3: Plant the crop and carry out routine management as needed until harvest.

[0019] As a preferred embodiment of the application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the crop is a crop variety with low potential for accumulating cadmium and arsenic.

[0020] As a preferred embodiment of the application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the application equipment comprises:

[0021] Eco-support system storage silos for storing eco-support system materials;

[0022] An inoculant storage silo for storing arbuscular mycorrhizal fungal inoculants;

[0023] A mobile platform for moving the ecological support system storage bin and the microbial agent storage bin, wherein the ecological support system storage bin and the microbial agent storage bin are arranged on the mobile platform;

[0024] A conveying system for ensuring the fluidity and continuity of solid materials during conveying, wherein the conveying system is arranged on a mobile platform;

[0025] A mixing device for uniformly mixing the materials before application, wherein one end of the conveying system is provided with a mixing device;

[0026] An application mechanism for uniformly applying or injecting solid materials into the soil, the application mechanism being arranged on one side of the mixing device;

[0027] The application control system is used to control the application mechanism, and the application control system is arranged on the application mechanism.

[0028] As a preferred embodiment of the application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the delivery system comprises:

[0029] A pipeline, wherein the pipeline is fixedly installed on the top of the mobile platform, and the bottom ends of the ecological support system storage bin and the microbial agent storage bin are both connected to the pipeline through a feed pipe with a valve provided thereon;

[0030] A fan, wherein the fan is fixedly installed in the pipeline;

[0031] A delivery pipe, wherein the delivery pipe is fixedly mounted on the side wall of the mobile platform, and the pipeline is located in the inner cavity of the delivery pipe;

[0032] A first support rod, wherein the first support rods are installed at both ends of the inner cavity of the delivery tube;

[0033] A first support plate, wherein the first support plate is fixedly installed between two groups of first support rods;

[0034] A first rotating shaft, the first rotating shaft is rotatably connected to the first supporting plate through a bearing;

[0035] An auger, the auger being fixedly mounted on one end of the first rotating shaft;

[0036] A first box body, wherein the first box body is fixedly mounted on a side wall of the first support plate;

[0037] A first servo motor, wherein the first servo motor is fixedly installed in the first housing, and an output shaft of the first servo motor is fixedly connected to the first rotating shaft;

[0038] The arc-shaped pipe is fixedly mounted on one end of the conveying pipe.

[0039] As a preferred embodiment of the application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the mixing device comprises:

[0040] A mixing box with rollers is provided at the bottom, and an arc-shaped pipe is fixedly installed at the top of the mixing box;

[0041] Guide plates, a plurality of guide plates arranged in a staggered manner are fixedly installed on the top of the mixing box;

[0042] A second support rod, with the second support rods being fixedly mounted at both ends of the inner cavity of the mixing box;

[0043] A second support plate, the second support plate is fixedly installed between the two sets of second support rods;

[0044] a second rotating shaft, the second rotating shaft being rotatably connected to the second supporting plate via a bearing;

[0045] A stirring shaft, a plurality of stirring shafts are fixedly mounted on the bottom end of the second rotating shaft;

[0046] A second box body, wherein the second box body is fixedly mounted on the top of the second supporting plate;

[0047] A second servo motor, wherein the second servo motor is fixedly mounted in the second housing, and an output shaft of the second servo motor is fixedly connected to the second rotating shaft;

[0048] A discharge pipe with a valve is arranged on the discharge pipe, and the discharge pipe is fixedly mounted on the bottom end of the mixing box.

[0049] As a preferred embodiment of the application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system described in the present invention, the application mechanism comprises:

[0050] An application box with rollers at the bottom, a discharge pipe fixedly installed at the bottom of the side wall of the application box, and an application control system fixedly installed at the top of the application box;

[0051] A discharge port, the discharge port being opened on the bottom end of the side wall of the application box;

[0052] A hose with a valve disposed thereon, the hose being fixedly installed in the discharge port;

[0053] A cylinder body, the cylinder body being fixedly mounted on one end of the hose;

[0054] A stepper motor, wherein the stepper motor is fixedly mounted on the bottom of the application box;

[0055] The box body is fixedly mounted on the output shaft of the stepper motor

[0056] A cylinder, wherein the cylinder is fixedly installed in the box body;

[0057] A connecting plate is fixedly mounted on the cylinder via a piston rod, and the connecting plate is fixedly mounted on one side of the cylinder body.

[0058] Compared with existing technologies:

[0059] The restoration effect is significant: through the synergistic effect of arbuscular mycorrhizal fungi and the ecological support system, the bioavailability of cadmium and arsenic in the soil can be effectively reduced, and the accumulation of heavy metals in plants can be reduced, thereby improving the restoration effect.

[0060] Healthy plant growth: Arbuscular mycorrhizal fungi can enhance the stress resistance of plants and, combined with the improvement of the soil environment by the ecological support system, promote the healthy growth of crops.

[0061] Uniform and precise application: The application equipment designed in the present invention can accurately control the application amount and application depth of the repair composition, ensure the uniform distribution of arbuscular mycorrhizal fungi and the ecological support system in the soil, and avoid the unevenness and dosage control problems in traditional application methods.

[0062] Wide application: This invention is not only suitable for the remediation of cadmium-arsenic complex pollution in farmland soil, but can also be applied to the remediation of other types of heavy metal contaminated soil. It has broad application prospects and significant environmental and economic benefits.

[0063] In summary, the present invention provides an efficient and environmentally friendly solution for the remediation of heavy metal contaminated soil through innovative combination and application technologies, which significantly improves the remediation effect and plant growth performance, and provides strong support for agricultural production safety and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is a schematic diagram of cadmium concentration in the root system of plants inoculated with arbuscular mycorrhizal fungi (AMF) and set up an ecological support system (HAP) according to Example 1 of the present invention;

[0065] Figure 2 This is a schematic diagram of arsenic absorption by the aboveground part of plants inoculated with arbuscular mycorrhizal fungi (AMF) and set up an ecological support system (HAP) according to Example 1 of the present invention;

[0066] Figure 3 A schematic diagram of cadmium concentration in the root system of plants inoculated with arbuscular mycorrhizal fungi (AMF) and set up an ecological support system (HAP+BC) according to Example 2 of the present invention;

[0067] Figure 4 This is a schematic diagram of arsenic absorption by the aboveground part of plants inoculated with arbuscular mycorrhizal fungi (AMF) and set up an ecological support system (HAP+BC) according to Example 2 of the present invention;

[0068] Figure 5 It is a schematic diagram of the application equipment of the present invention;

[0069] Figure 6 It is a front view schematic diagram of the storage bin, bacterial agent storage bin and conveying system structure of the ecological support system of the present invention;

[0070] Figure 7 For the present invention Figure 6 A schematic diagram of the structure enlargement in the middle;

[0071] Figure 8 It is a front view schematic diagram of the mixing device of the present invention;

[0072] Fig. 9 It is a front view schematic diagram of the application mechanism structure of the present invention;

[0073] Fig.10 For the present invention Fig. 9 Enlarged schematic diagram of the structure at point B in the middle.

[0074] In the figure: ecological support system storage bin 1, microbial agent storage bin 2, conveying system 3, pipeline 31, fan 32, first support rod 33, first support plate 34, first rotating shaft 35, auger 36, first box 37, first servo motor 38, mixing device 4, guide plate 41, second support rod 42, second support plate 43, second rotating shaft 44, stirring shaft 45, second box 46, second servo motor 47, discharge pipe 48, application control system 5, application mechanism 6, discharge port 61, hose 62, cylinder 63, box 64, cylinder 65, connecting plate 66, mobile platform 7. DETAILED DESCRIPTION

[0075] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0076] The present invention provides a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system. Figure 1-Figure 10, including the arbuscular mycorrhizal fungus Heterosporium heterorhizogenes and ecological support systems;

[0077] The arbuscular mycorrhizal fungus Heterosporangium includes Heterosporangium; the inoculant of Heterosporangium is a mixture of host plant root segments, mycorrhizal fungal spores and extraradical mycelium, and its spore density is 50 to 90 spores / g.

[0078] The ecological support system includes hydroxyapatite and biochar, which can reduce the bioavailability of cadmium and arsenic in the soil and promote the healthy growth of plants; the addition amount of hydroxyapatite is 0.5-2% of the soil mass; the addition amount of biochar is 0.5-3% of the soil mass, and it is formed by high-temperature pyrolysis of straw biomass, with a pH value of 8.5-9.

[0079] A method for applying a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system comprises the following specific steps:

[0080] Step 1: applying the composition to the farmland soil contaminated with cadmium and arsenic by using an application device;

[0081] Step 2: Mix the soil and the composition thoroughly, and add water as needed to maintain soil moisture;

[0082] Step 3: Plant crops and carry out routine management as needed until harvest. The crops should be varieties with low potential for cadmium and arsenic accumulation.

[0083] The application equipment includes: an ecological support system storage bin 1 for storing ecological support system materials; a microbial agent storage bin 2 for storing arbuscular mycorrhizal fungal inoculants; a mobile platform 7 for moving the ecological support system storage bin 1 and the microbial agent storage bin 2, on which the ecological support system storage bin 1 and the microbial agent storage bin 2 are arranged; a conveying system 3 for ensuring the fluidity and continuity of solid materials during the conveying process, the conveying system 3 is arranged on the mobile platform 7; a mixing device 4 for uniformly mixing the materials before application, one end of the conveying system 3 is provided with the mixing device 4; an application mechanism 6 for uniformly applying or injecting the solid materials into the soil, the application mechanism 6 is arranged on one side of the mixing device 4; an application control system 5 for controlling the application mechanism 6, and the application control system 5 is arranged on the application mechanism 6;

[0084] The conveying system 3 includes: a pipeline 31, a fan 32, a first support rod 33, a first support plate 34, a first rotating shaft 35, an auger 36, a first box 37, a first servo motor 38, a conveying pipe, and an arc pipe;

[0085] The pipeline 31 is fixedly installed on the top of the mobile platform 7, and the bottom ends of the ecological support system storage bin 1 and the microbial agent storage bin 2 are connected to the pipeline 31 through a feed pipe with a valve provided thereon, the fan 32 is fixedly installed in the pipeline 31, the conveying pipe is fixedly installed on the side wall of the mobile platform 7, and the pipeline 31 is located in the inner cavity of the conveying pipe, and the first support rods 33 are installed at both ends of the inner cavity of the conveying pipe, the first support plate 34 is fixedly installed between the two groups of first support rods 33, the first rotating shaft 35 is rotatably connected to the first support plate 34 through a bearing, the auger 36 is fixedly installed on one end of the first rotating shaft 35, the first box body 37 is fixedly installed on the side wall of the first support plate 34, the first servo motor 38 is fixedly installed in the first box body 37, and the output shaft of the first servo motor 38 is fixedly connected to the first rotating shaft 35, and the arc tube is fixedly installed on one end of the conveying pipe.

[0086] The working principle of the conveying system 3 is as follows: when the materials in the ecological support system storage bin 1 and the microbial agent storage bin 2 fall into the pipeline 31, the materials will be blown into the conveying pipe by the fan 32. At this time, the auger 36 will be rotated by the first servo motor 38, so that the materials can be conveyed.

[0087] The mixing device 4 comprises: a mixing box with rollers at the bottom, a guide plate 41, a second support rod 42, a second support plate 43, a second rotating shaft 44, a stirring shaft 45, a second box body 46, a second servo motor 47, and a discharge pipe 48 with a valve thereon;

[0088] An arc tube is fixedly installed on the top of the mixing box, a plurality of staggered guide plates 41 are fixedly installed on the top of the mixing box, second support rods 42 are fixedly installed on both ends of the inner cavity of the mixing box, a second support plate 43 is fixedly installed between the two groups of second support rods 42, a second rotating shaft 44 is rotatably connected to the second support plate 43 through a bearing, a plurality of stirring shafts 45 are fixedly installed on the bottom end of the second rotating shaft 44, a second box body 46 is fixedly installed on the top of the second support plate 43, a second servo motor 47 is fixedly installed in the second box body 46, and the output shaft of the second servo motor 47 is fixedly connected to the second rotating shaft 44, and a discharge pipe 48 is fixedly installed on the bottom end of the mixing box.

[0089] The working principle of the mixing device 4 is as follows: when the material falls into the mixing box, the material will be mixed for the first time through the guide plate 41, and then the second rotating shaft 44 will drive the stirring shaft 45 to rotate through the second servo motor 47, so that the material can be mixed for the second time.

[0090] The application mechanism 6 includes: an application box with a roller at the bottom, a discharge port 61, a hose 62 with a valve, a cylinder 63, a box body 64, a cylinder 65, a connecting plate 66, and a stepping motor;

[0091] A discharge pipe 48 is fixedly installed on the bottom end of the side wall of the application box, and an application control system 5 is fixedly installed on the top end of the application box. A discharge port 61 is opened on the bottom end of the side wall of the application box, a hose 62 is fixedly installed in the discharge port 61, a cylinder 63 is fixedly installed on one end of the hose 62, a stepper motor is fixedly installed on the bottom of the application box, a box body 64 is fixedly installed on the output shaft of the stepper motor, a cylinder 65 is fixedly installed in the box body 64, a connecting plate 66 is fixedly installed on the cylinder 65 through a piston rod, and the connecting plate 66 is fixedly installed on one side of the cylinder body 63.

[0092] Working principle of application mechanism 6: The height of cylinder 63 is adjusted by air cylinder 65, so that cylinder 63 can be located above the soil to sprinkle the composition on the soil, or cylinder 63 can be inserted into the soil to inject the composition into the soil. When the composition is sprinkled on the soil, the spreading range of the composition can be adjusted by a stepping motor.

[0093] in:

[0094] Inoculant storage bin 2 is specially used to store arbuscular mycorrhizal fungi inoculants. To ensure that the inoculants remain highly active before application, the storage bin is designed with excellent moisture-proof and pollution-proof functions. The temperature and humidity of the environment in the bin are monitored in real time by sensors and maintained within an appropriate range through an automatic adjustment system to prevent the inoculants from being inactivated or contaminated due to changes in environmental conditions.

[0095] The ecological support system storage bin 1 is used to store the components of the ecological support system, including inorganic and organic components, such as hydroxyapatite and biochar. In order to prevent these materials from getting damp and agglomerating or reacting with impurities in the air, the storage bin adopts a high sealing design and has moisture-proof and pollution-proof functions. In addition, a stirring device (including but not limited to a second support rod 42, a second support plate 43, a second rotating shaft 44, a stirring shaft 45, a second box 46 and a second servo motor 47) can also be provided in the ecological support system storage bin 1 to prevent the material from settling or agglomerating during storage and ensure uniform fluidity during application.

[0096] The conveying system 3 uses an auger 36 to accurately convey the microbial agent and the materials of the ecological support system to the outlet of the application equipment. The auger 36 is equipped with an adjustable conveying speed control system, which controls the conveying amount of the material by changing the rotation speed of the auger 36 to ensure the uniformity of the application amount. In addition, the inner wall of the auger 36 is coated with antistatic material to prevent the powdered or granular materials from sticking or clogging during the conveying process;

[0097] During the conveying process, the mixing device 4 can evenly mix the microbial agent and the materials of the ecological support system to ensure consistency during the application process, so as to achieve efficient mixing in a short time and ensure that the materials reach the best uniform state before entering the application device.

[0098] The application control system 5 is the control unit of the equipment. The operator can adjust the various working parameters of the application equipment through the control panel, including application amount, application speed, application depth, etc. The system presets multiple application modes and can automatically adjust the application process according to the actual soil conditions to achieve the best restoration effect.

[0099] The application mechanism 6 is suitable for spraying the materials with ecological support system and mycorrhizal fungi inoculants evenly on the soil surface to ensure the uniformity of spraying, and can adapt to different soil conditions by adjusting the spraying width and depth. In addition, since the hose 62 is set to be inclined, the occurrence of blockage will be avoided, ensuring the stability of continuous application. When it is necessary to inject the microbial agent and ecological support system materials directly into the soil, the cylinder 63 can be injected deep into the soil to ensure that the repair material can effectively act on the most polluted soil layer, maximize the repair efficiency, and the injection depth can be adjusted to meet the needs of different soil pollution layers.

[0100] Mobile platform 7 refers to the application equipment mounted on a tractor or automatic walking platform. The platform is equipped with GPS positioning and path planning functions to ensure that the application equipment can be accurately operated in large areas of farmland. The platform's path planning system can optimize the application route according to the shape and size of the field, maximize application efficiency, and reduce the risk of repeated application or missed application. The stability design of the automatic walking platform also ensures that the equipment can operate smoothly under complex terrain conditions, further improving the efficiency of restoration.

[0101] The present invention includes but is not limited to the following embodiments:

[0102] Example 1

[0103] In this embodiment, three treatment groups were set up to explore the effects of different remediation measures on corn growth and heavy metal accumulation in cadmium-arsenic composite contaminated soil. The first treatment group was a blank group (CK), without any inoculation or addition, mainly used for comparative analysis; the second treatment group was an arbuscular mycorrhizal fungus (AMF) inoculation group, which was intended to study the effects of AMF on corn growth and heavy metal absorption; the third treatment group was an AMF inoculation and ecological support system (hydroxyapatite application) (AMF+HAP) group, which combined the synergistic effect of AMF and HAP to evaluate its passivation effect on the bioavailability of soil cadmium and arsenic and its promotion of plant growth.

[0104] The blank group (CK) was not inoculated or added and served as the control group. This group only sowed corn seeds in the soil to observe the natural growth of corn without intervention. The test soil was obtained from the surface soil of farmland contaminated by cadmium and arsenic, with cadmium (Cd) and arsenic (As) contents of 5.78 mg / kg and 194.8 mg / kg, respectively. The soil was evenly fertilized before the experiment to ensure the normal growth of plants in the seedling stage. The amount of soil per pot was 1.2 kg, and the soil was fully mixed before sowing. In the AMF treatment group, the soil was inoculated with arbuscular mycorrhizal fungi. The test strain was Rhizophagus irregularis, and its inoculant consisted of a mixture of host plant root segments, mycorrhizal fungal spores and extraradical mycelium, with a spore density of about 60 / g. The inoculation method was layering, that is, 50g of the inoculant was fully mixed with the soil at a height of 3 / 4 from the bottom of the pot. Subsequently, corn seeds were sown and maintained, ensuring the same water and fertilizer management conditions as the blank group. In the AMF+HAP treatment group, hydroxyapatite was added to the soil on the basis of inoculation with arbuscular mycorrhizal fungi, and the addition amount was 1% of the soil mass. The particle size of hydroxyapatite used was 5-20 μm. The operation of inoculating AMF and applying hydroxyapatite was the same as the above method. After uniform mixing, corn seeds were sown and managed.

[0105] All treatment groups were tested under greenhouse conditions, with the greenhouse environment controlled at 25°C (day) / 18°C (night), a photoperiod of 16h / 8h, and a relative humidity of 70%. The experimental period was 65 days. At the end of the experiment, corn plant samples were harvested to determine plant biomass, mycorrhizal infection rate, and cadmium (Cd) and arsenic (As) contents in the root system and aboveground parts. Data were analyzed for variance using SPSS27 software.

[0106] The experimental results showed that after inoculation with arbuscular mycorrhizal fungi (AMF), the mycorrhizal infection rate of corn was in the range of 5.71% to 9.12%. In the AMF inoculation and ecological support system treatment group (AMF+HAP), the mycorrhizal infection rate increased significantly to 15.33% to 24.20%. This data change clearly shows that the establishment of an ecological support system can effectively enhance the colonization effect of AMF in the corn root system.

[0107] In terms of plant growth performance, an increase in corn biomass was observed in the AMF-inoculated treatment group. In particular, in the AMF-inoculated and ecological support system treatment group (AMF+HAP), the root biomass was 22.53% higher than that in the AMF-inoculated group alone. This finding strongly proves that the construction of the ecological support system has a significant promoting effect on root growth.

[0108] Regarding heavy metal accumulation, after AMF inoculation, the cadmium (Cd) concentration in the corn root system decreased to a certain extent. It is worth noting that in the AMF inoculation and ecological support system treatment group (AMF+HAP), the Cd concentration and absorption amount decreased more significantly, with the root Cd concentration decreasing by 4.50%. This result fully demonstrates that the combined application of AMF and ecological support system has a significant effect in reducing the bioavailability of cadmium ( Figure 1 ).

[0109] In terms of arsenic (As) accumulation, the As absorption of the aboveground part of corn increased by 8.2% after inoculation with AMF. However, in the group inoculated with AMF and set up with ecological support system (AMF+HAP), the As content in the aboveground part decreased by 11.2%. This comparison further proves that the combination of AMF and ecological support system can effectively reduce the transfer of arsenic in soil to plants ( Figure 2 ).

[0110] The present invention significantly improves the remediation effect of cadmium-arsenic composite contaminated soil by introducing arbuscular mycorrhizal fungi and setting up an ecological support system. Compared with single treatment, the combined use not only improves the growth performance of plants, but also significantly reduces the biological effectiveness of heavy metals in the soil. The increase in mycorrhizal infection rate further confirms the positive role of the ecological support system in promoting AMF colonization, which is of great significance for building efficient and sustainable farmland soil remediation technology. Based on the traditional AMF inoculation technology, the present invention innovatively introduces an ecological support system (such as hydroxyapatite), overcomes the shortcomings of a single remediation method in a heavy metal composite contaminated environment, and makes the remediation effect more significant. In addition, in agricultural production, the present invention ensures the safety of crops by reducing the heavy metal content in plants, and has broad application prospects and economic benefits.

[0111] Example 2

[0112] In this example, three treatments were studied on the effects of corn growth and heavy metal accumulation in soil contaminated with cadmium and arsenic, namely: only setting up an ecological support system control group (BC), inoculating arbuscular mycorrhizal fungi and setting up an ecological support system (applying biochar) (AMF+BC), and inoculating arbuscular mycorrhizal fungi and setting up a composite ecological support system group (applying hydroxyapatite and biochar) (AMF+HAP+BC). This study aims to explore the combined effect of the composite ecological support system and arbuscular mycorrhizal fungi.

[0113] In the BC treatment group, biochar was added to the soil contaminated with cadmium and arsenic at an amount of 1% of the soil mass. The biochar used was corn straw biochar with a pH of 9 and was prepared by high-temperature pyrolysis. The experimental soil was fully mixed after the application of biochar to ensure the uniform distribution of biochar in the soil. The AMF+BC treatment group was further inoculated with arbuscular mycorrhizal fungi (AMF) on the basis of biochar application. The specific operation was as follows: in each pot of soil, after applying biochar according to the method in the BC treatment group, Rhizophagus irregularis was inoculated. The inoculant consisted of a mixture of host plant root segments, mycorrhizal fungal spores and extraradical mycelium, with a spore density of about 60 / g. The inoculation was carried out by layering, that is, 50g of the inoculant was fully mixed with the soil at a height of 3 / 4 from the bottom of the pot. In the AMF+HAP+BC treatment group, in addition to inoculating arbuscular mycorrhizal fungi and applying biochar, hydroxyapatite (HAP) was also added to the soil. The specific operation is as follows: first, biochar was applied according to the method in treatment group 3, and hydroxyapatite was added to the soil at 1% of the soil mass. The particle size of the hydroxyapatite used was 5-20 μm, and the purity was BR grade. The treated soil was placed in a plastic pot (1.2 kg of soil was placed in each pot), and corn seeds were sown in the pot after disinfection and germination, with 5 seeds sown in each pot. After the seedlings emerged, 2 plants were retained by thinning. During the experiment, sterile deionized water was added regularly every day to maintain the soil moisture at the set level.

[0114] All treatment groups were tested under the same greenhouse conditions, with a temperature of 25°C / 18°C (day / night), a photoperiod of 16h / 8h, and a relative humidity of 70%. The experimental period was 65 days. At the end of the experiment, corn plant samples were harvested to measure soil pH, available phosphorus content, and cadmium (Cd) and arsenic (As) content in the root system and aboveground parts. All data were analyzed by variance analysis using SPSS27 software.

[0115] The experimental results showed that compared with the treatment of setting up a single ecological support system (BC), the combined treatment of inoculating arbuscular mycorrhizal fungi (AMF) and setting up an ecological support system (AMF+BC) could significantly reduce the pH value of the soil and increase the available phosphorus content by 6.7%. This change effectively improved the physical and chemical properties of the soil, which in turn helped to reduce the bioavailability of cadmium (Cd) and arsenic (As) in the soil.

[0116] Further analysis of plant cadmium accumulation showed that the treatment group inoculated with arbuscular mycorrhizal fungi and set up an ecological support system (AMF+HAP+BC) significantly reduced the Cd concentration in the aboveground part of corn. Specifically, compared with the BC treatment group, the Cd concentration in the aboveground part of this treatment group was reduced by 60.2%; and compared with the AMF+BC treatment group, it was reduced by 56.2% ( Figure 3). In terms of arsenic accumulation, the treatment group inoculated with arbuscular mycorrhizal fungi and set up an ecological support system (AMF+HAP+BC) also showed a significant reduction effect. Compared with the BC treatment group, the As content in the aboveground part of this treatment group decreased by 56.8%; and compared with the AMF+BC treatment group, it decreased by 51.9% ( Figure 4 ).

[0117] The results of Example 2 show that arbuscular mycorrhizal fungi and the establishment of an ecological support system have a significant synergistic effect in repairing soil contaminated by cadmium and arsenic. In particular, the AMF+HAP+BC treatment group not only significantly increased the mycorrhizal infection rate of plants, but also significantly reduced the cadmium and arsenic concentrations in plant tissues, showing an excellent repair effect, verifying the innovation of the present invention.

[0118] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system, characterized in that: Includes the arbuscular mycorrhizal fungus Heterosporium and ecological support systems; The arbuscular mycorrhizal fungus Heteromorpha includes Heteromorpha; The ecological support system includes hydroxyapatite and biochar, so as to reduce the bioavailability of cadmium and arsenic in the soil and promote the healthy growth of plants.

2. A soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 1, characterized in that: The inoculant of heteromorphic rhizosporon is prepared by mixing the root segments of host plants, mycorrhizal fungi spores and extra-root mycelium, and the spore density is 50 to 90 spores / g.

3. A soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 1, characterized in that: The added amount of the hydroxyapatite is 0.5-2% of the soil mass.

4. The soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 1, characterized in that: The biochar is added in an amount of 0.5-3% of the soil mass, and is formed by high-temperature pyrolysis of straw biomass, with a pH value of 8.5-9.

5. An application method of a soil remediation composition based on arbuscular mycorrhizal fungi and an ecological support system, characterized in that: The specific steps are as follows: Step 1: applying the composition to the farmland soil contaminated with cadmium and arsenic by using an application device; Step 2: Mix the soil and the composition thoroughly, and add water as needed to maintain soil moisture; Step 3: Plant the crop and carry out routine management as needed until harvest.

6. The application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 5, characterized in that: The crops are crop varieties with low potential for accumulating cadmium and arsenic.

7. The application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 5, characterized in that: The application device comprises: An eco-support system storage bin (1) for storing eco-support system materials; An inoculant storage bin (2) for storing arbuscular mycorrhizal fungal inoculant; A mobile platform (7) for moving the ecological support system storage bin (1) and the bacterial agent storage bin (2), wherein the ecological support system storage bin (1) and the bacterial agent storage bin (2) are arranged on the mobile platform (7); A conveying system (3) for ensuring the fluidity and continuity of solid materials during conveying, wherein the conveying system (3) is arranged on a mobile platform (7); A mixing device (4) for uniformly mixing the materials before application, wherein one end of the conveying system (3) is provided with the mixing device (4); An application mechanism (6) for uniformly applying or injecting solid materials into the soil, the application mechanism (6) being arranged on one side of the mixing device (4); An application control system (5) is used to control an application mechanism (6), and the application control system (5) is arranged on the application mechanism (6).

8. The application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 7, characterized in that: The conveying system (3) comprises: A pipeline (31), wherein the pipeline (31) is fixedly installed on the top of the mobile platform (7), and the bottom ends of the ecological support system storage bin (1) and the bacterial agent storage bin (2) are both connected to the pipeline (31) through a feed pipe with a valve provided thereon; A fan (32), wherein the fan (32) is fixedly installed in the pipeline (31); A delivery pipe, the delivery pipe is fixedly mounted on the side wall of the mobile platform (7), and the pipeline (31) is located in the inner cavity of the delivery pipe; A first support rod (33), with the first support rod (33) being installed at both ends of the inner cavity of the delivery tube; A first support plate (34), the first support plate (34) being fixedly mounted between the two groups of first support rods (33); A first rotating shaft (35), the first rotating shaft (35) being rotatably connected to the first supporting plate (34) via a bearing; An auger (36), wherein the auger (36) is fixedly mounted on one end of the first rotating shaft (35); A first box body (37), the first box body (37) being fixedly mounted on a side wall of the first support plate (34); A first servo motor (38), wherein the first servo motor (38) is fixedly installed in the first housing (37), and an output shaft of the first servo motor (38) is fixedly connected to the first rotating shaft (35); The arc-shaped pipe is fixedly mounted on one end of the conveying pipe.

9. The application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 8, characterized in that: The mixing device (4) comprises: A mixing box with rollers is provided at the bottom, and an arc-shaped pipe is fixedly installed at the top of the mixing box; Guide plates (41), a plurality of guide plates (41) arranged in a staggered manner are fixedly mounted on the top of the mixing box; A second support rod (42), the second support rod (42) being fixedly mounted at both ends of the inner cavity of the mixing box; A second support plate (43), the second support plate (43) being fixedly mounted between the two sets of second support rods (42); A second rotating shaft (44), the second rotating shaft (44) being rotatably connected to the second supporting plate (43) via a bearing; A stirring shaft (45), a plurality of stirring shafts (45) are fixedly mounted on the bottom end of the second rotating shaft (44); A second box (46), the second box (46) is fixedly mounted on the top of the second support plate (43); A second servo motor (47), wherein the second servo motor (47) is fixedly installed in the second housing (46), and an output shaft of the second servo motor (47) is fixedly connected to the second rotating shaft (44); A discharge pipe (48) with a valve is provided on the discharge pipe (48), and the discharge pipe (48) is fixedly installed on the bottom end of the mixing box.

10. The application method of the soil remediation composition based on arbuscular mycorrhizal fungi and ecological support system according to claim 9, characterized in that: The application mechanism (6) comprises: An application box with rollers at the bottom, a discharge pipe (48) is fixedly installed at the bottom end of the side wall of the application box, and an application control system (5) is fixedly installed at the top end of the application box; A discharge port (61), the discharge port (61) being opened on the bottom end of the side wall of the application box; A hose (62) with a valve is provided thereon, and the hose (62) is fixedly installed in the discharge port (61); A cylinder (63), wherein the cylinder (63) is fixedly mounted on one end of the hose (62); A stepper motor, wherein the stepper motor is fixedly mounted on the bottom of the application box; A box body (64), wherein the box body (64) is fixedly mounted on the output shaft of the stepping motor; A cylinder (65), wherein the cylinder (65) is fixedly installed in the box body (64); A connecting plate (66), the cylinder (65) is fixedly mounted on the connecting plate (66) via a piston rod, and the connecting plate (66) is fixedly mounted on one side of the cylinder (63).

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