Ecological rod for ecological restoration of subsidence crack area of mining area as well as preparation method and application of ecological rod

Abstract

The invention discloses an ecological rod for ecological restoration of a subsidence crack area of a mining area as well as a preparation method and application of the ecological rod. The ecological rod is prepared from the following raw materials in percentage by weight: 85-89% of wood chips, 8-12% of organic matters, 1% of a water-retaining agent and 2% of activated carbon. The ecological rod has the functions of water and soil conservation, water conservation, wind prevention and sand fixation. By improving the air permeability and the water retention capacity of the soil, the ecological rods are beneficial to reducing water evaporation and soil erosion, so that the structural integrity of the soil is kept, and water and soil loss is reduced. Meanwhile, organic matters and nutrient elements contained in the ecological rods can provide a good growth environment for the plants, root growth and nutrient absorption of the plants are promoted, then the vegetation coverage rate is increased, and exposure of exposed soil is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological environment governance, and in particular to an ecological stick used for ecological restoration of subsidence and crack areas in mining areas, and a preparation method and application thereof. Background Art

[0002] While promoting the growth of the national economy, the development and utilization of coal resources have inevitably had a profound impact on the land ecosystem. Long-term mining activities often lead to serious problems such as ground subsidence and ground cracks. These subsidence and cracks not only destroy the microstructure of the soil, but also affect the evaporation and infiltration of soil moisture, ultimately leading to a series of chain reactions such as loose soil structure, reduced water storage and fertilizer retention capacity, reduced soil quality, water shortages, and surface vegetation degradation. These problems seriously threaten the quality and stability of the ecosystem, making the ecological environment extremely fragile. Therefore, it is urgent to carry out ecological restoration of coal mining subsidence and crack areas.

[0003] Ecological restoration technology not only focuses on the restoration of land production capacity, but also emphasizes the reconstruction of an artificial ecosystem that is in harmony with the surrounding environment and has a stable biological community. Its goal is to restore or even surpass the ecological functions of the original ecosystem. This process usually involves the use of ecological engineering such as soil matrix improvement, vegetation restoration, soil animals and microorganisms.

[0004] Traditional ecological restoration methods for subsidence crack areas, such as filling with solid waste such as coal gangue and fly ash, or leveling the land by digging deep and filling shallow, sparse drainage and other means, have solved the problem to a certain extent. However, in terms of soil reconstruction, the traditional one-time filling method and mud pump reclamation process often lead to soil structure disorder and large-scale nutrient loss, which is not conducive to the recovery of land productivity. Therefore, these methods need to be further optimized to improve the effect of ecological restoration.

[0005] Eco-sticks are an innovative material used for ecological restoration and greening. They are designed to promote vegetation growth, restore and protect the ecological environment by retaining water, fertilizer and soil. However, the materials used in traditional eco-sticks may not be suitable for the specific environmental conditions of the mining area (such as soil type, climate conditions, etc.), thus affecting the restoration effect. Currently, there is still a lack of eco-sticks made according to the specific ecological environment of the mining area. Summary of the invention

[0006] The present invention aims to provide an ecological stick for ecological restoration of subsidence and crack areas in mining areas, and a preparation method and application thereof, so as to better achieve ecological restoration of subsidence and crack areas in mining areas.

[0007] In order to achieve the above object, according to one aspect of the present invention, an eco-stick for ecological restoration of subsidence and crack areas in mining areas is provided. The raw materials of the eco-stick are prepared according to the following weight ratio: 85-89% sawdust, 8-12% organic matter, 1% water retaining agent and 2% activated carbon.

[0008] Furthermore, the raw materials of the eco-stick are prepared according to the following weight ratios: 87% sawdust, 10% organic matter, 1% water-retaining agent and 2% activated carbon; or 85% sawdust, 12% organic matter, 1% water-retaining agent and 2% activated carbon; or 89% sawdust, 8% organic matter, 1% water-retaining agent and 2% activated carbon.

[0009] Furthermore, the sawdust comes from native vegetation in the subsidence crack area; preferably, the water retaining agent is polyacrylamide; preferably, the organic matter is sphagnum peat soil with an organic matter content of ≥95%, a fiber thickness of 0-10mm, and a pH value of 5.5-7.0; preferably, the activated carbon is analytically pure activated carbon.

[0010] Furthermore, the specifications of the eco-stick are a cylinder with a diameter of 5 cm and a length of 50 cm.

[0011] Furthermore, the eco-stick is prepared by the following steps: the raw materials are uniformly mixed according to a weight ratio; the uniformly mixed raw materials are softened at 340-360° C. and then extruded to obtain the eco-stick.

[0012] According to another aspect of the present invention, a method for preparing the above-mentioned ecological stick for ecological restoration of mining area subsidence and crack areas is provided. The preparation method comprises: mixing the raw materials uniformly according to the weight ratio; softening the uniformly mixed raw materials at 340-360°C and then extruding to form the ecological stick.

[0013] According to another aspect of the present invention, a method for ecological restoration of subsidence and crack areas in mining areas is provided, which comprises: using any of the above-mentioned ecological sticks for ecological restoration of subsidence and crack areas in mining areas to perform ecological restoration.

[0014] Furthermore, the ecological restoration includes: laying out a four-point ecological stick grid, the unit size of the grid is 20-30cm×20-30cm; preferably, the grid is square.

[0015] Furthermore, the method also includes the step of monitoring the ecological restoration effect of the subsidence and crack area.

[0016] Furthermore, the steps of monitoring the ecological restoration effect of the subsidence crack area include: monitoring the ecological restoration effect from the first precipitation, the monitoring period is the entire growing season, the monitoring time interval is 15 days, and the soil moisture and nutrient changes on both sides of the crack area and the native vegetation recovery effect are monitored during the period; based on the monitoring of the ecological restoration test effect, the soil physical and chemical properties and plant diversity are investigated during the peak period of plant aboveground biomass, and a comprehensive evaluation is conducted on the soil improvement and native vegetation restoration effects in the test area.

[0017] The eco-stick of the present invention has the functions of soil and water conservation, water source conservation and wind and sand fixation. By improving the air permeability and water retention capacity of the soil, the eco-stick helps to reduce water evaporation and soil erosion, thereby maintaining the structural integrity of the soil and reducing soil and water loss. At the same time, the organic matter and nutrient elements contained in the eco-stick can provide a good growth environment for plants, promote the root growth and nutrient absorption of plants, thereby increasing the vegetation coverage rate and reducing the exposure of bare soil. The roots and above-ground parts of these vegetation can form a stable plant community, effectively resist the erosion of wind and sand, fix sand grains, and play a role in wind and sand fixation.

[0018] In addition, the structural characteristics and material composition of the eco-rod in the present invention also provide favorable conditions for the increase of biodiversity. The pore structure and specific surface area in the eco-rod are large, providing a suitable living space for small organisms such as microorganisms and insects, promoting their reproduction and activities. At the same time, the organic matter and nutrients rich in the eco-rod provide a rich source of nutrition for microorganisms, enhancing the diversity and vitality of soil microorganisms. This is of great significance for maintaining the ecosystem function of the soil, promoting the decomposition and circulation of soil organic matter, and providing a rich food chain foundation. Therefore, by using the eco-rod, functions such as soil and water conservation, water conservation, wind and sand fixation can be achieved, and ultimately biodiversity can be improved, promoting the restoration and improvement of the ecological environment in the coal mining subsidence crack area. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of the development and application process of an eco-stick according to an embodiment of the present application is shown;

[0021] Figure 2 The schematic diagram of the structure of the eco-stick in Example 1 of the present application is shown;

[0022] Figure 3 A schematic diagram of the layout of the ecological rod grid in Example 1 of the present application is shown;

[0023] Figure 4A schematic plan view of the repair test area in Example 1 of the present application is shown;

[0024] Figure 5 A schematic plan view of the repair test area in Example 2 of the present application is shown;

[0025] Figure 6 A schematic diagram showing the vegetation growth after one year of the experiment in Example 1 of the present application is shown;

[0026] Figure 7 A schematic diagram showing the vegetation growth after one year of the experiment in Example 2 of the present application is shown;

[0027] Figure 8 A schematic diagram of soil moisture content in the 0-50 cm soil layer under different restoration technologies in Example 4 of the present application is shown. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In order to solve the problem that the existing ecological sticks are not suitable for filling surface cracks, soil conservation, moisture conservation and maintenance in subsidence areas of mining areas, the inventors of this application have conducted in-depth research and provided an ecological stick for ecological restoration of subsidence cracks in mining areas. The ecological stick has low cost, large specific surface area, good adsorption performance, and can loosen and ventilate the soil, retain moisture, and improve fertility.

[0030] In a typical embodiment of the present application, in order to seek the raw material composition and specification parameters of the ecological stick suitable for ecological restoration of mining subsidence crack areas, the inventor conducted the following experiments (see Figure 1 ), the steps include:

[0031] Step 1: Combine field surveys and indoor experiments to obtain the characteristics of crack development, soil erosion, soil moisture stress, and vegetation degradation in coal mining subsidence areas;

[0032] Step 2: Based on the characteristic data collected in step 1, design the material ratio, diameter and length of the eco-stick.

[0033] Preferably, the raw data in step 1 include: soil moisture content, soil pH, soil nutrient content (including total nitrogen, total phosphorus, alkaline nitrogen, available phosphorus, available potassium, organic matter content), plant diversity, coal mining area climate data, sampling point location information, and mining information such as coal mining face location, length, width, mining depth, mining height, advancement direction, and advancement speed. The specific steps are as follows:

[0034] S11. Based on the characteristics of the cracks in the selected mining area, the crack areas were numbered and typical crack sampling points 1, 2, and 3 were selected. CK was the sampling point of the control area (crack influence area). ①, ②, ③, ④, ⑤, and ⑥ represented the 0-10 cm, 10-20 cm, 20-30 cm, and 30-50 cm soil layers, respectively;

[0035] S12. Based on the selected sampling points and sampled soil layers, soil physical and chemical index tests are performed on the sampled items;

[0036] Preferably, the sampling items and detection methods of the sampling points in S12 are as follows:

[0037] "Soil Testing Part 24: Determination of Total Nitrogen in Soil - Automatic Nitrogen Determination Method" (NY / T 1121.24-2012);

[0038] "Determination of phosphorus in forest soil: Total phosphoric acid dissolution method" (LY / T 1232-2015);

[0039] "Determination of nitrogen in forest soil: Determination of hydrolyzable nitrogen" (LY / T 1228-2015);

[0040] "Soil Testing Part 7: Determination of Available Phosphorus in Soil" (NY / T 1121.7-2014);

[0041] "Determination of soil available potassium and slow-release potassium content" (NY / T 889-2004);

[0042] "Determination of water content of forest soil: drying method" (LY / T 1213-1999);

[0043] "Soil Testing Part 2: Determination of Soil pH" (NY / T 1121.2-2006);

[0044] “Soil Testing Part 6: Determination of Soil Organic Matter” (NY / T 1121.6-2006).

[0045] S13. Conduct plant sample surveys on native vegetation in the mining fissure area and the control area to obtain parameters such as species abundance, frequency, height, cover, biomass, and calculate species richness, diversity, and evenness indexes based on the "Biodiversity Survey and Monitoring Standards" (T / CGDF 2886861-2020).

[0046] Preferably, step 2 comprises the following steps:

[0047] S21. Based on the original data of soil moisture and vegetation damage within the coal mining area in S12, an eco-rod composed of a variety of materials such as matrix (wood chips), water retaining agent (polyacrylamide), fertilizer (organic matter), pore-forming agent (activated carbon) was designed, and the material ratio with the best water-fertilizer environmental effect was screened through experiments. Carry out the water diffusion test of the eco-rod, and finally optimize the specifications of the eco-rod according to the current status of surface ecological damage and species diversity distribution in the subsidence and crack area. The eco-rod is processed by a rod making machine, and its principle is to use the pressure of the screw to extrude the high-temperature softened raw materials into shape. Through the above production process, an eco-rod with optimized specifications is obtained to cope with the soil problems in the subsidence and crack area, and provide good support and protection for plant growth.

[0048] More preferably, the specific steps of S21 are as follows:

[0049] (1) Prepare raw materials: According to the soil type and texture characteristics of the subsidence crack area, design an ecological stick composed of a variety of materials such as matrix (wood chips), water retaining agent (polyacrylamide), fertilizer (organic matter), and pore-forming agent (activated carbon).

[0050] (2) Processing of raw materials: Process the sawdust and crush it into particles with a size of 0.4-0.8 mm. Polyacrylamide can be used directly, and organic matter can be processed by composting or other methods. Analytically pure polyacrylamide (CAS: 9003-0-5-8) and activated carbon (powder) do not need to be ground and can be added directly. Preferably, the organic matter is sphagnum peat soil with an organic matter content of ≥ 95%, a fiber size of 0-10 mm, and a pH value of 5.5-7.0. The activated carbon is laboratory analytical pure activated carbon (CAS: 7440-44-0). (3) Material ratio: Determine the optimal material ratio based on the results of the orthogonal test. Determine the proportion of each material based on the physical and chemical properties of the soil in the subsidence crack area and mix them evenly.

[0051] (4) Rod making machine processing: The mixed materials are fed into the rod making machine. The rod making machine uses the pressure of the spiral device to extrude the raw materials softened at high temperature into shape. According to the design requirements, the parameters of the rod making machine, such as temperature, pressure and speed, are adjusted to ensure that the specifications of the eco-rods meet the requirements. For example, the mixed raw materials are softened at 340-360°C and then extruded to obtain eco-rods. Among them, the softening of the raw materials at 340-360°C is mainly to make the materials of the eco-rods reach a certain plastic state for subsequent processing and molding. This temperature range can change the molecular structure of the material, increase its fluidity and plasticity, so that it can be better cross-laid and needle-punched to form high-strength geotechnical materials. Such a processing process helps the eco-rods maintain their structural stability and functionality in subsequent applications, such as corrosion resistance and non-combustibility.

[0052] (5) Check the quality: During the production process of the eco-stick, check the quality of the eco-stick regularly. Check for broken or uneven parts, and make necessary adjustments and repairs.

[0053] (6) Finished product processing: After the eco-sticks are made, they are cleaned and packaged to ensure the hygiene and safety of the eco-sticks for transportation and storage.

[0054] In a typical embodiment of the present application, the inventors also performed the following experimental steps:

[0055] Step 3: Carry out on-site ecological restoration in the subsidence and crack areas and lay out ecological rod grids;

[0056] Step 4: Monitor the soil moisture, nutrients and vegetation growth in the restoration test area, and conduct a comprehensive assessment of the soil moisture retention and native vegetation restoration effects in the restoration test area.

[0057] Preferably, step three comprises the following steps:

[0058] S31. Select representative test areas based on the characteristics of soil and vegetation degradation in mining subsidence areas;

[0059] S32. Based on the characteristics of the mining fracture area, the mining fracture area is selected as the test area, and the number and area of ​​the test area are determined;

[0060] S33. Based on the improved eco-rods made in S21 and the test areas selected in S31 and S32, a four-point eco-rod grid is laid out in the mining fracture test area (the grid unit has a grid unit size of 20-30 cm×20-30 cm, preferably, the grid is square, for example, 25 cm×25 cm);

[0061] S34. Based on the results of field research and indoor analysis, an ecological restoration experiment is carried out in the area where the ecological stick grid is laid.

[0062] Preferably, the specific steps of the ecological restoration test in S34 are:

[0063] (1) Before the test, the soil moisture content at different depths of 0 to 0.5 m on both sides of the crack was measured using a moisture sensor;

[0064] (2) Fill cracks and level the terrain;

[0065] (3) Using a steel hollow drill rod, select typical ground fissures in the 1#, 2#, and 3# ecological restoration test areas, and drill holes on both sides of the fissures at 25 cm × 25 cm horizontal and vertical intervals, with a drilling depth of 50 cm (four-point ecological rod grid);

[0066] (4) Insert the developed 50 cm long ecological rod into the steel hollow drill rod, and fill the pores around the ecological rod with original soil and compact it;

[0067] (5) The above-mentioned ecological stick restoration experiment was not carried out in the control area.

[0068] Preferably, the step 4 comprises the following steps:

[0069] S41. Based on the ecological sticks and after the completion of the test site work, the ecological restoration effect monitoring will start from the first precipitation. The monitoring period is the entire growing season, and the monitoring interval is 15 days. During this period, the soil moisture and nutrient changes on both sides of the crack area and the restoration effect of native vegetation will be monitored;

[0070] S42. Based on the monitoring of the effects of the ecological restoration experiment, investigate the physical and chemical properties of the soil and plant diversity during the peak period of plant aboveground biomass, conduct a comprehensive assessment of the effects of soil improvement and native vegetation restoration in the experimental area, and issue an assessment report.

[0071] Through the above experiments, this application finally obtained the following series of technical solutions.

[0072] According to a typical embodiment of the present application, an eco-stick for ecological restoration of subsidence and crack areas in mining areas is provided. The raw materials of the eco-stick are prepared according to the following weight ratio: 85-89% sawdust, 8-12% organic matter, 1% water retainer and 2% activated carbon. More preferably, in an embodiment of the present application, the raw materials of the eco-stick are prepared according to the following weight ratio: 87% sawdust, 10% organic matter, 1% water retainer and 2% activated carbon; or 85% sawdust, 12% organic matter, 1% water retainer and 2% activated carbon; or 89% sawdust, 8% organic matter, 1% water retainer and 2% activated carbon.

[0073] The eco-stick of the present application has the functions of soil and water conservation, water conservation and wind and sand fixation. By improving the air permeability and water retention capacity of the soil, the eco-stick helps to reduce water evaporation and soil erosion, thereby maintaining the structural integrity of the soil and reducing soil and water loss. At the same time, the organic matter and nutrient elements contained in the eco-stick can provide a good growth environment for plants, promote the root growth and nutrient absorption of plants, thereby increasing the vegetation coverage rate and reducing the exposure of bare soil. The roots and above-ground parts of these vegetation can form a stable plant community, effectively resist the erosion of wind and sand, fix sand grains, and play a role in wind and sand fixation.

[0074] In addition, the structural characteristics and material composition of the eco-sticks in this application also provide favorable conditions for the increase of biodiversity. The pore structure and specific surface area in the eco-sticks are large, providing a suitable living space for small organisms such as microorganisms and insects, promoting their reproduction and activities. At the same time, the organic matter and nutrients rich in the eco-sticks provide a rich source of nutrition for microorganisms, enhancing the diversity and vitality of soil microorganisms. This is of great significance for maintaining the ecosystem function of the soil, promoting the decomposition and circulation of soil organic matter, and providing a rich food chain foundation. Therefore, by using eco-sticks, functions such as soil and water conservation, water conservation, wind and sand fixation can be achieved, and ultimately biodiversity can be improved, promoting the restoration and improvement of the ecological environment in coal mining subsidence crack areas.

[0075] The beneficial effects of the present invention will be further described below in conjunction with embodiments.

[0076] Example 1

[0077] During the research and development process, the inventor conducted an in-depth analysis based on the ecological characteristics of the subsidence crack area to ensure the selection of the best material ratio, so that the eco-rod can maximize the water-fertilizer environmental effect, improve the water holding rate, and maintain a high water supply under various climatic conditions, thereby providing strong support and guarantee for the ecological restoration of the subsidence crack area in the mining area. Through the application of the eco-rod, the local ecological environment is significantly improved, biodiversity is restored, and sustainable development is promoted.

[0078] The steps of this embodiment include:

[0079] Step 1: Combine field surveys and indoor experiments to obtain the characteristics of crack development, soil erosion, soil moisture stress, and vegetation degradation in coal mining subsidence areas;

[0080] The original data in step one include: soil moisture content, soil pH, soil nutrient content (including total nitrogen, total phosphorus, alkaline nitrogen, available phosphorus, available potassium, and organic matter content), plant diversity, coal mining area climate data, sampling point location information, and coal mining face location, length, width, mining depth, mining height, advancement direction, and advancement speed information.

[0081] Step 1 specifically includes:

[0082] S11. Based on the characteristics of the cracks in the selected mining area, the crack areas are numbered and typical crack sampling points 1, 2, and 3 are selected. CK is the sampling point of the control area (crack influence area). ①, ②, ③, ④, ⑤, and ⑥ represent the 0-10cm, 10-20cm, 20-30cm, and 30-50cm soil layers, respectively.

[0083] S12. Based on the selected sampling points and sampled soil layers, soil physical and chemical index tests are conducted on the sampling items.

[0084] Preferably, the sampling items and detection methods of the sampling points in S12 are as shown in Table 1 below:

[0085] Table 1

[0086] Test items Detection Methods Total nitrogen "Soil Testing Part 24: Determination of Total Nitrogen in Soil - Automatic Nitrogen Determination Method" (NY / T 1121.24-2012) Total Phosphorus "Determination of phosphorus in forest soil: Total phosphoric acid dissolution method" (LY / T 1232-2015) Alkaline nitrogen "Determination of nitrogen in forest soil: Determination of hydrolyzable nitrogen" (LY / T 1228-2015) Available Phosphorus "Soil Testing Part 7: Determination of Available Phosphorus in Soil" (NY / T 1121.7-2014) Fast-Acting Potassium "Determination of soil available potassium and slow-release potassium content" (NY / T 889-2004) Water content "Determination of water content of forest soil: drying method" (LY / T 1213-1999) pH "Soil Testing Part 2: Determination of Soil pH" (NY / T 1121.2-2006) Organic matter "Soil Testing Part 6: Determination of Soil Organic Matter" (NY / T 1121.6-2006)

[0087] Step 2: Design the diameter and length of the eco-rod based on the surface damage, soil and vegetation characteristics in the coal mining subsidence crack area;

[0088] Step 2 includes the following steps:

[0089] S21. Based on the original data of soil moisture and vegetation damage in the coal mining area described in S12, an eco-rod composed of multiple materials such as matrix (sawdust), water retaining agent (polyacrylamide), fertilizer (organic matter), pore-forming agent (activated carbon) was designed, and the material ratio with the best water-fertilizer environmental effect was selected through orthogonal experiments. The results showed that the eco-rod with a ratio of 87% sawdust + 10% organic matter + 1% water retaining agent + 2% activated carbon had the best performance. An eco-rod moisture diffusion test was carried out, and according to the current status of surface ecological damage in the subsidence and crack area and the distribution law of species diversity, the eco-rod was finally optimized to be cylindrical in shape as a whole, with specifications of 5cm in diameter and 50cm in length ( Figure 2 Middle a, Figure 2 b). This design not only meets the needs of ecological restoration, but is also easy to operate and arrange in practical applications. The internal structure of the eco-rod is porous, a feature that enables it to effectively store water and nutrients, thereby promoting plant growth and soil improvement. The eco-rod is processed using a rod making machine, the principle of which is to use the pressure of the screw to extrude the raw materials softened at high temperature (340-360℃) into shape. Through the above production process, optimized eco-rods with suitable specifications can be obtained to cope with soil problems in subsidence crack areas and provide good support and protection for plant growth.

[0090] The eco-stick performs well in improving soil aeration and can effectively increase the circulation of air in the soil, thereby providing the necessary oxygen for plant roots, which is essential for the normal growth of plants. In addition, it has excellent water retention ability and can store the right amount of water in the soil, so that plants can still get enough water during droughts and reduce growth problems caused by insufficient water. More importantly, the function of the eco-stick in improving soil aeration will also provide a strong guarantee for the healthy growth of the root system. Good aeration not only helps the roots breathe, but also helps promote microbial activity, thereby improving the overall health of the soil. These combined advantages will directly improve the growth of plants, making them stronger and more luxuriant.

[0091] Step 3: Carry out on-site ecological restoration in the subsidence and crack areas and lay out ecological rod grids, including:

[0092] S31. Based on the characteristics of soil and vegetation degradation in the mining subsidence area, a representative test area is selected; in this embodiment, the technical test is conducted in the surface selection test area of ​​22206, 22208, and 22210 working faces of Daliuta Coal Mine of Shenhua Coal Group;

[0093] S32. Based on the characteristics of mining fracture areas, mining fracture areas are selected as test areas. The area of ​​each test area is >100m 2 ;

[0094] S33, based on the improved ecological sticks made in S21 and the test areas selected in S31 and S32, a four-point ecological stick grid (grid unit is 25cm×25cm) is laid in the mining fracture test area. The layout of the restoration test area is shown in Figure 4 ;

[0095] S34. Based on the results of field research and indoor analysis, an ecological restoration experiment is carried out in the area where the ecological stick grid is laid.

[0096] S34 Specific steps of ecological restoration experiment:

[0097] (1) Before the test, the soil moisture content at different depths of 0 to 0.5 m on both sides of the crack was measured using a moisture sensor;

[0098] (2) Fill the cracks, level the terrain, and fill the crack structures such as Figure 3 As shown;

[0099] (3) Use steel hollow drill rods to drill in the 1#, 2#, and 3# ecological restoration test areas (layout reference Figure 5 ) Select a typical ground crack and drill holes on both sides of the crack at a horizontal and vertical interval of 25 cm × 25 cm, with a drilling depth of 50 cm (four-point ecological rod grid);

[0100] (4) Insert the developed 50 cm long ecological rod into the steel hollow drill rod, and fill the pores around the ecological rod with original soil and compact it;

[0101] (5) The above-mentioned ecological stick repair was not carried out on both sides of the crack area, which served as a control for the repair area.

[0102] Step 4: Based on the basic information of the coal mining area, monitor the soil moisture, nutrients and vegetation growth in the restoration test area, and conduct a comprehensive evaluation of the soil moisture retention and native vegetation restoration effects in the restoration test area.

[0103] Step 4 includes the following steps:

[0104] S41. Based on the ecological sticks and after the completion of the test site work, the ecological restoration effect monitoring will start from the first precipitation. The monitoring period is the entire growing season, and the monitoring interval is 15 days. During this period, the soil moisture and nutrient changes on both sides of the crack area and the restoration effect of native vegetation will be monitored;

[0105] S42. Based on the monitoring of the effects of ecological restoration experiments, during the peak period of aboveground biomass of plant communities, a third-party agency shall be commissioned to conduct a comprehensive assessment of the effects of soil moisture retention and native vegetation restoration in the restoration experimental area and issue an assessment report, or to assess the species importance and species diversity and issue an assessment report;

[0106] S43, based on the soil physical and chemical indicators of the test area and the control area in S41 and S42, and conducting comparative analysis, observing the ecological restoration effect of the test area;

[0107] In the present embodiment, before the ecological restoration test was carried out in the test area, the total nitrogen content in the soil varied widely, with a maximum of 596 mg / kg (0-10 cm soil layer in the three-mining crack area) and a minimum of 19 mg / kg (30-50 cm L1F2-⑥ in the one-mining crack area), indicating that the soil nitrogen supply capacity in the study area was significantly different; the alkaline nitrogen that was not detected in the soil samples indicated that the soil in the region may have certain problems in terms of nitrogen availability, which may limit crop growth, and the data of the nitrogen-phosphorus ratio, alkaline nitrogen and available phosphorus of the soil showed that the soil fertility of some samples was good, which was conducive to plant growth, while other samples showed potential nutrient deficiency or imbalance. The soil nitrogen and phosphorus content of some layers is relatively low, which may lead to slow plant growth, and fertilization or improvement measures need to be considered. From the surface downward (such as 10-30 cm, 30-50 cm, etc.), the nitrogen and phosphorus content in the soil is generally reduced, and this phenomenon generally indicates that the nutrient accumulation of deep soil is not as good as that of the surface layer. This may be because the deep soil lacks effective nutrient supply, and the microbial activity is relatively low. The contents of nutrients such as nitrogen, phosphorus, alkaline nitrogen and available phosphorus in the control area (no mining cracks) were significantly higher than those in the experimental area. This phenomenon indicates that the soil in the control area exhibits more superior characteristics in terms of physical and chemical properties. At the same time, the high contents of alkaline nitrogen and available phosphorus mean that the soil in this area not only has a good nutrient supply capacity, but also contributes to the growth of vegetation. Therefore, these data further illustrate that the soil environmental conditions in the area without mining cracks are more suitable, which is conducive to the healthy growth of plants and the stability of the ecosystem. The capillary water holding capacity of soil samples in the control area ranged from 15.45% to 27.74%, and the high capillary water holding capacity indicates that these areas can effectively retain water. The lower bulk density in the experimental area usually means that the soil has a low water capacity, which is not conducive to plant growth. The spatial structure of porosity in the control and experimental areas is quite different, which affects the flow of water and air. The control area has a higher porosity and usually has good drainage capacity, while the low porosity in the experimental area indicates that the soil may accumulate water, leading to root hypoxia.

[0108] More importantly, these adverse soil conditions not only threaten the survival of individual species, but also have a negative impact on the health of the entire ecosystem. When vegetation growth is restricted, the surface cover will be reduced, making the soil more susceptible to erosion and degradation. At the same time, the reduction of vegetation will also affect the local microclimate, reduce air humidity, and thus have a chain reaction on the surrounding ecological environment.

[0109] In addition, with the reduction of vegetation, the diversity of the ecosystem may be destroyed, which will affect the habitat of animals and microorganisms that rely on these vegetation for survival. In the long run, this vicious cycle may lead to the destruction of the ecological balance in the area and may even cause land desertification and ecological imbalance. Therefore, it is particularly urgent to improve the physical and chemical properties and water content of the soil in the experimental area to promote the recovery of vegetation and the sustainable development of the ecological environment.

[0110] In order to solve the problem of ecological damage caused by mining subsidence in the above-mentioned mining areas, this embodiment introduces an optimized and improved ecological rod. The ecological rod has a developed pore structure, a large specific surface area, and good adsorption performance. It can loosen and ventilate the soil and retain moisture. According to the typical geological mining conditions of repeated mining of multiple coal seams, a research method combining theoretical analysis, field investigation, research and development of repair materials, and on-site repair tests is adopted. According to the characteristics of soil and water loss, soil moisture stress and vegetation destruction in mining crack areas, the impact of cracks on key ecological elements such as soil and vegetation is explained, and porous, water-retaining ecological rods with a certain strength are designed. Typical mining crack areas are selected to carry out on-site ecological restoration technology experiments to enhance the water retention of the surface soil and the wind and sand fixation effect of the surface, so as to achieve rapid restoration of native vegetation.

[0111] After the repair test in the subsidence crack area, the soil physical and chemical properties and water content in the test area were comprehensively evaluated again, and it was found that the repair measures significantly affected the physical and chemical properties of the soil. The organic matter content of the shallow soil (0-50cm) increased from 4.8g / kg to 6.5g / kg. This change shows that the repair measures effectively promoted the activity of soil microorganisms and the decomposition of plant residues, thereby improving the fertility of the soil. In addition, the content of alkaline nitrogen also showed a significant increase, which means that the nitrogen supply capacity of the soil has been enhanced, which is beneficial to the growth and development of crops. The content of available phosphorus also increased, which played a positive role in promoting the root development and nutrient absorption of plants. The organic matter content in the soil. In general, these changes reflect the success of the repair experiment and lay a good foundation for improving the soil quality and improving the ecological environment in the region.

[0112] Example 2

[0113] The difference between Example 2 and Example 1 is that the layout of the repair test area is different (layout reference Figure 6 ), according to the direction and number of surface cracks in the subsidence area, it can be flexibly adjusted in actual application.

[0114] This example conducts an in-depth study on the typical geological mining conditions produced by repeated mining of multiple coal seams. A comprehensive approach was adopted, including theoretical analysis, field investigation, research and development of repair materials, and field repair tests. These methods complement each other and provide a more comprehensive understanding and response to the complex impacts of multi-coal seam mining. In this example, a typical mining fracture area was selected and field ecological restoration technology tests were carried out in the area.

[0115] After the ecological restoration test was carried out using the ecological sticks prepared in Example 1, the soil bulk density of the 0-50cm soil layer decreased by 15.2%, and the soil organic matter content increased by 35.4%, significantly improving the soil structure; through the analysis of the species survey results, it was found that the species richness index and species diversity index were significantly improved, which shows that the ecological restoration experiment significantly improved the water-holding capacity and biodiversity of the soil in the area. In addition, it was observed that the growth of some vegetation was also greatly improved, and the vegetation was more lush, especially in the test area. Compared with the situation before the test, the change was very obvious ( Figure 7 ). In contrast, the control area where no measures were taken showed almost no change, which further demonstrated the positive impact of the restoration experiment using the modified eco-sticks. In summary, this embodiment effectively improved the soil water retention capacity and biodiversity in the test area by using eco-sticks, demonstrating the great potential of ecological restoration technology in improving soil quality and promoting plant growth.

[0116] Example 3

[0117] It is basically the same as Example 1, except that the raw material composition of the eco-stick is: 85% sawdust + 12% organic matter + 1% water retaining agent + 2% activated carbon or 89% sawdust + 8% organic matter + 1% water retaining agent + 2% activated carbon.

[0118] This embodiment carried out an on-site ecological restoration experiment in the same area as embodiment 1. After one year of restoration, the soil physical and chemical properties and vegetation parameters in the ecological restoration area are shown in Table 2 and Table 3, respectively.

[0119] Table 2 Physical and chemical properties of soil in the 0-50 cm layer under different restoration technologies

[0120]

[0121]

[0122] Note: The data in the charts are mean ± standard error. The same below.

[0123] Table 3 Community species diversity and aboveground biomass under different restoration technologies

[0124]

[0125] In the three types of ecological stick restoration technology tests, the physical and chemical properties of the soil in the restoration area, the species diversity of the community, and the aboveground organisms have all improved to varying degrees compared to the unrestored area. Among them, the content of total nitrogen, alkaline nitrogen, total phosphorus, and organic matter in the soil and the aboveground biomass of the community have increased significantly, indicating that the ecological sticks with three raw material ratios have a good restoration effect on both soil and vegetation. In addition, the ecological sticks in Example 1 have a better restoration effect than the two ecological sticks of 85% sawdust + 12% organic matter + 1% water retainer + 2% activated carbon and 89% sawdust + 8% organic matter + 1% water retainer + 2% activated carbon.

[0126] Comparative Example 1

[0127] It is basically the same as Example 1, except that the raw material composition of the eco-stick is: 80% sawdust + 17% organic matter + 1% water retaining agent + 2% activated carbon.

[0128] In the process of preparing this type of eco-sticks in this embodiment, it was found that when the organic matter content is high, the eco-sticks are difficult to be squeezed into regular cylinders by the stick making machine and are easy to break, which affects the later filling of surface cracks with eco-sticks and the layout of the eco-stick grid, resulting in poor ecological restoration effects.

[0129] Comparative Example 2

[0130] It is basically the same as Example 1, except that the raw material composition of the eco-stick is: 93% sawdust + 4% organic matter + 1% water retaining agent + 2% activated carbon.

[0131] The organic matter content of the eco-sticks in this example is low. After filling the subsidence cracks and decomposing, the total nitrogen, total phosphorus and organic matter content of the soil on both sides of the cracks are not significantly different from those in the control area, indicating that its impact on the soil nutrient status is limited and the ecological restoration effect is poor.

[0132] Example 4

[0133] It is basically the same as Example 1, except that the four-point ecological stick grid units are 20cm×20cm and 30cm×30cm.

[0134] This example and Example 1 carried out an on-site ecological restoration experiment in the same area. Since the first rainfall, the soil moisture content of the 0-50 cm soil layer in the restoration area of ​​the three grid units was monitored at an interval of 15 days. The results are as follows Figure 8 shown.

[0135] 45 days after the restoration test began, the soil moisture content of the 0-50cm soil layer under the three ecological stick restoration technologies was significantly higher than that of the unrestored area, indicating that the three ecological stick grids have a good restoration effect on the soil. Among them, the soil moisture content in Example 1 is slightly higher than that in this example.

[0136] Comparative Example 3

[0137] It is basically the same as Example 1, except that the four-point ecological rod grid unit is 15cm×15cm.

[0138] In this embodiment, the ecological rod grid is relatively dense, and the original vegetation and surface soil structure are greatly damaged during its deployment. At the same time, the workload is large, which affects the later ecological restoration effect.

[0139] Comparative Example 4

[0140] The invention is basically the same as Example 1, except that the four-point ecological rod grid unit is 35 cm×35 cm. The field ecological restoration test was carried out in the same area as Example 1. After monitoring for one growing season, the results showed that the soil moisture content of the 0-50 cm soil layer was not significantly different from that of the unrepaired area (control area), and the restoration effect was not obvious.

[0141] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the eco-stick of the present invention has the functions of soil and water conservation, water source conservation and wind and sand fixation. By improving the air permeability and water retention capacity of the soil, the eco-stick helps to reduce water evaporation and soil erosion, thereby maintaining the structural integrity of the soil and reducing soil and water loss. At the same time, the organic matter and nutrient elements contained in the eco-stick can provide a good growth environment for plants, promote the root growth and nutrient absorption of plants, thereby increasing the vegetation coverage rate and reducing the exposure of bare soil. The roots and above-ground parts of these vegetation can form a stable plant community, effectively resist the erosion of wind and sand, fix sand particles, and play a role in wind and sand fixation.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ecological stick for ecological restoration of subsidence and crack areas in mining areas, characterized in that: The raw materials of the eco-stick are prepared according to the following weight ratio: 85-89% sawdust, 8-12% organic matter, 1% water retaining agent and 2% activated carbon.

2. The eco-stick according to claim 1, characterized in that: The raw materials of the eco-stick are prepared according to the following weight ratio: 87% wood chips, 10% organic matter, 1% water retaining agent and 2% activated carbon; or 85% wood chips, 12% organic matter, 1% water retaining agent and 2% activated carbon; or 89% wood chips, 8% organic matter, 1% water retaining agent and 2% activated carbon.

3. The eco-stick according to claim 1 or 2, characterized in that: The wood chips come from native vegetation in the subsidence fissure area; Preferably, the water retaining agent is polyacrylamide; Preferably, the organic matter is sphagnum peat soil with an organic matter content of ≥95%, a fiber thickness of 0-10 mm, and a pH value of 5.5-7.0; Preferably, the activated carbon is analytically pure activated carbon.

4. The eco-stick according to claim 1 or 2, characterized in that: The specifications of the eco-stick are a cylinder with a diameter of 5 cm and a length of 50 cm.

5. The eco-stick according to claim 1, characterized in that: The eco-stick is prepared by the following steps: Mix the raw materials evenly according to the weight ratio; The uniformly mixed raw materials are softened at 340-360° C. and then extruded to obtain the ecological stick.

6. A method for preparing an ecological stick for ecological restoration of a mining area subsidence fissure area as claimed in any one of claims 1 to 5, characterized in that: include: Mix the raw materials evenly according to the weight ratio; The uniformly mixed raw materials are softened at 340-360° C. and then extruded to obtain the ecological stick.

7. A method for ecological restoration of subsidence and crack areas in mining areas, characterized in that: include: Ecological restoration is carried out using the ecological rod for ecological restoration of subsidence and crack areas in mining areas as described in any one of claims 1 to 5.

8. The method according to claim 7, characterized in that The ecological restoration includes: laying out a four-point ecological stick grid, wherein the unit size of the grid is 20-30 cm×20-30 cm; Preferably, the grid is square.

9. The method according to claim 7 or 8, characterized in that: The method also includes the step of monitoring the ecological restoration effect of the subsidence and crack area.

10. The method according to claim 9, characterized in that The steps of monitoring the ecological restoration effect of the subsidence crack area include: The monitoring of ecological restoration effects began from the first rainfall, the monitoring period was the entire growing season, and the monitoring interval was 15 days. During this period, the soil moisture and nutrient changes on both sides of the crack area and the restoration effect of native vegetation were monitored; Based on the monitoring of the effects of the ecological restoration experiment, the physical and chemical properties of the soil and plant diversity were investigated during the peak period of plant aboveground biomass, and a comprehensive evaluation was conducted on the effects of soil improvement and native vegetation restoration in the experimental area.

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