Method for rapidly regreening acid mine soil through energy plants

Abstract

The invention relates to a method for rapidly regreening acid mine soil through energy plants. The method for rapidly regreening acid mine soil through the energy plants is implemented through the following steps that S1, mine soil treatment is conducted, specifically, a soil conditioner is evenly spread on the exposed to-be-restored earth surface of a mine; s2, preparing a water-retaining matrix; s3, planting of energy plants: digging planting holes, putting a water-retaining substrate, performing cuttage to cultivate seedlings, and transplanting the seedlings into the planting holes; and S4, the ground cover grass seeds are sown to fully cover the ground surface. According to the method for rapidly regreening the acid mine soil by planting the energy plants, the acid soil is subjected to acid-base neutralization and restoration treatment by adopting organic fertilizer, lime and a conditioner, then the fast-growing energy plant pennisetum hydridum is planted to harvest and manufacture a large amount of biomass energy raw materials, and the other bare earth surface is covered with broadcast-sown screened ground cover herbs, so that the energy plants are planted to rapidly revive the acid mine soil. Therefore, the purposes of soil restoration, water and soil conservation, energy biomass production and other ecological economy are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of mine soil ecological restoration, and in particular to a method for rapidly regreening acidic mine soil with energy plants. Background Art

[0002] With the rapid development of industry, the demand for energy is increasing, and mineral resources are mined and utilized on a large scale. However, due to weak environmental awareness and immature mining technology, many mine wastes such as tailings ponds and spoil dumps are left behind while mining ore resources. These mine wastes have many slags left after mineral processing or processing. Their physical and chemical properties are different from those of ordinary surface soil, causing soil acidification and heavy metal pollution. There are also many nutrients such as nitrogen, phosphorus, and potassium required for normal plant growth. Therefore, vegetation often cannot grow normally on the ground of these mine wastes. At the same time, heavy metals in the soil of such mine wastes are easily enriched, causing the heavy metal content of agricultural products to exceed the standard, bringing major food safety risks. Humans living near polluted areas or ingesting them through the food chain cause harm to the body.

[0003] In recent years, people have conducted a lot of research on the remediation of acidic contaminated soil in mining areas. Common remediation methods in the research include physical engineering remediation, such as soil removal method, electrochemical method, etc.; chemical remediation, such as the use of modifiers, chelating agents, precipitants, etc.; and plant remediation. Among them, physical remediation measures have good effects and wide adaptability, but high costs, and are only suitable for remediation in small areas with serious pollution; chemical remediation is prone to secondary pollution. Compared with the three, plant remediation technology has been accepted by people for its advantages of being harmless to the environment, easy to implement, sustainable development, good landscape effects and low investment costs, and has become one of the research hotspots for contaminated soil remediation. Plant remediation technology is divided into three types: plant extraction, plant volatilization and plant fixation. Plant extraction is the plant remediation technology with the best remediation effect and the most promising development prospects. Planting suitable regreening plants on contaminated soil, using plants to enrich and transfer heavy metals in the soil, can achieve the effects of soil and water conservation in mining areas, improving soil environment and greening mines. However, the current phytoremediation technology has certain limitations. One of the key problems it faces is that the soil in mining areas is highly acidic and poisoned by heavy metals, which slows plant growth and reduces biomass. Another problem is that the heavy metal content in the soil exceeds the standard, and it is necessary to select hyperaccumulator plants that have strong tolerance, can adapt to growing in contaminated soil and have the ability to absorb and enrich heavy metals. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a method for quickly regreening acidic mining soil with energy plants, using organic fertilizer, lime and conditioner to carry out acid-base neutralization and repair treatment on the acidic soil, and using grass and shrubs to make a water-retaining matrix, and then planting fast-growing energy plants such as king grass to harvest and produce a large amount of biomass energy raw materials, and covering the remaining exposed surface with screened ground cover herbs, so as to achieve the ecological and economic purposes of repairing the soil, conserving water and soil, and producing energy biomass.

[0005] A method for rapidly regreening acidic mine soil with energy plants is implemented by the following steps:

[0006] S1, mine soil treatment: evenly spread the soil conditioner on the exposed surface of the mine to be repaired, use equipment to mix the surface soil layer with a thickness of 25 to 35 cm, and let it leach with rainwater for at least one month before planting vegetation;

[0007] S2, preparing a water-retaining matrix: composting grass clippings, and mixing the composted grass clippings with yellow mud in a certain proportion to obtain a water-retaining matrix;

[0008] S3, Energy Plant Planting: Dig a planting hole and put in a water-retaining substrate, then cultivate the seedlings by cuttings, and transplant them into the planting hole when the seedling height and root length grow to more than 5cm. After watering thoroughly for planting and rooting, fill the topsoil and compact it into a nest shape to store water around the roots of the plants;

[0009] S4, sowing ground cover grass seeds to fully cover the ground surface: after planting energy plants, sow ground cover grass seeds and irrigate and water the plants on site in real time during the non-rainy season.

[0010] Furthermore, the soil conditioner is one or more of lime, organic fertilizer and conditioner.

[0011] Furthermore, calculated by volume weight ratio of the soil in the surface layer of 30 cm, the soil conditioner includes 1-5% lime, 1-10% organic fertilizer and 0.05-0.2% conditioner in mass fraction.

[0012] Preferably, the soil conditioner comprises 2% lime, 2% organic fertilizer and 0.1% conditioner in mass fraction.

[0013] Furthermore, the conditioning agent is an alkaline substance including porous carbon powder, and the porous carbon powder accounts for 70-85% of the total mass of the conditioning agent.

[0014] Furthermore, the conditioning agent also includes potassium, silicon and calcium. The effective nutrients include 10-25% calcium, 1-20% silicon and 0-5% potassium; wherein the clinker providing calcium is one or more of calcium magnesium phosphate fertilizer, silicon calcium magnesium fertilizer or other calcium-containing fertilizers; the clinker providing silicon is one or more of calcium magnesium phosphate fertilizer, silicon calcium magnesium soil conditioner and silicon fertilizer; the clinker providing potassium is potassium-containing fertilizer.

[0015] Furthermore, in step S2, the step of composting the grass is as follows: the harvested grass is broken into grass clippings with a length of 5 to 8 cm, 0.1 to 1% of a rotten grass agent and 0.1 to 1% of urea are sprinkled therein, the grass is watered thoroughly, and the grass is covered with a plastic film for composting. It should be noted that if the length of the grass clippings is too short, it is not conducive to forming a ball with the soil to fix the root system, and if it is too long, it is easy to produce too large pores, which is not conducive to water retention and water absorption.

[0016] Preferably, the dosage of the stem rot agent is 0.2%; the dosage of the urea is 0.5%.

[0017] Furthermore, in step S2, the mass ratio of the composted grass clippings to the yellow mud is 2:1.

[0018] Furthermore, the energy plant is King Grass, which is a plant of the genus Pennisetum in the Poaceae family, with wide adaptability, strong stress resistance, strong acid resistance, large biomass, high yield, and good regreening effect. The ground cover grass seed is Wedelia chrysantha that has been soaked and germinated to make it white, and the germination is convenient for the grass seeds to germinate quickly and ensure the seedling rate.

[0019] The method for rapidly regreening acidic mine soil with energy plants also includes:

[0020] S5, regularly harvest energy plants to produce biomass raw materials: When the energy plants grow to 2m, they can be harvested and used to make water-retaining matrix or bio-pellet fuel.

[0021] Among them, the water-retaining matrix can be returned to the mine to be repaired to achieve the purpose of continuously improving the mine soil; the biomass pellet fuel can be used for boiler combustion to achieve full utilization of energy plants, and the boiler ash can be used for heavy metal recovery or landfilled in designated landfills.

[0022] The beneficial effects of the present invention are as follows: while utilizing lime to neutralize acidic soil, organic fertilizer is added, and the two act synergistically, thereby increasing the content of soil organic matter, promoting microbial reproduction, enhancing soil buffering performance and enzyme activity, and contributing to stabilizing the acidic soil restoration effect; adding a conditioner can effectively reduce the amount of organic fertilizer used and reduce the cost of mine regreening; and then planting king grass as an energy plant has wide adaptability, strong stress resistance, strong acid resistance, large biomass, high yield, and good regreening effect.

[0023] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a linear relationship diagram of the pH value of lime and mine soil in Example 1;

[0025] Figure 2 It is a linear relationship diagram of the pH value of organic fertilizer and mine soil in Example 1;

[0026] Figure 3 It is a comparison chart of the plant height, tillering and leaf number of King Grass under different treatments in Comparative Example 1 and Example 2;

[0027] Figure 4 This is a schematic diagram of the biomass of King Grass at different organic fertilizer dosages in Example 2;

[0028] Figure 5 Flow chart of a method for rapid regreening of acidic mine soil with energy plants. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a method for mine soil disposal, comprising the following steps:

[0032] Mine soil preparation: The soil is taken from the tailings waste soil in the mining area, and its properties are shown in Table 1. Take the naturally dried mine soil, crush it, and pass it through a 2mm sieve for later use.

[0033] Preparation of the conditioner: porous carbon powder, calcium, silicon and potassium are mixed in a mass ratio of 80:15:3:2 to obtain a conditioner, and the pH of the conditioner is 11.5.

[0034] Table 1 Physical and chemical properties of mine soil

[0035]

[0036] Mine soil treatment: Take 6 portions of 10g of mine soil and place them in 50ml beakers respectively. First, add 0.70% organic fertilizer and 0.1% conditioner to each portion of mine soil. Then, add 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, and 0.30% lime to 6 portions of mine soil respectively. Finally, add CO2-free distilled water at a soil-liquid mass ratio of 1:2.5, stir or shake intermittently with a glass rod for 30 minutes, and measure the pH value with a precision pH meter after standing for 10 minutes. For details of the linear relationship between lime and pH value of mine soil, see Figure 1 .

[0037] Take another 6 portions of 10g of mining soil and place them in 50ml beakers respectively. First add 2% lime and 0.1% conditioner to each portion of mining soil, and then add 0.35%, 0.70%, 1.40%, 2.80%, 5.60%, and 11.20% of organic fertilizer to the 6 portions of mining soil respectively. Finally, add CO2-free distilled water at a soil-liquid mass ratio of 1:2.5, stir or shake intermittently with a glass rod for 30 minutes, and measure the pH value with a precision pH meter after standing for 10 minutes. For details of the linear relationship between organic fertilizer and pH value of mining soil, see Figure 2 .

[0038] Figure 1 is a linear relationship diagram of the pH value of lime and mine soil in this embodiment; Figure 2 It is the linear relationship diagram of the pH value of organic fertilizer and mine soil in this embodiment. Figure 1 As can be seen from the figure, R2 = 0.94, and the model has a high goodness of fit. Figure 1 The linear relationship in the calculation shows that when the pH value of the mine soil is 4, the amount of lime required is 2.41%. Figure 2 It can be seen that R 2 =0.98, the goodness of fit is very close to 1, and the model has a high goodness of fit. Figure 2 The linear relationship in the equation can be used to calculate that when the pH of the mine soil is 4, 5, and 6, the amount of organic fertilizer required is 9.70%, 14.70%, and 19.70%, respectively.

[0039] Example 2

[0040] The mine soil in this example is prepared in the same manner as in Example 1.

[0041] Energy plant seedling cultivation: In this example, King Grass was selected as the energy plant, and tap water was used for irrigation during the entire implementation process. The transplantation standard of the energy plant is: normal growth without tillering until the plant height reaches 20 cm.

[0042] This example adopts the soil culture potting method in the greenhouse, with 2 kg of mineral soil in each pot, and a water-retaining matrix added. Based on the linear relationship between the organic fertilizer and the pH value of the mine soil obtained in the example, three treatments are set as shown in Table 2, with 6 replicates for each treatment, and repeated mixing. One king grass is transplanted in each pot, and the planting time is 90 days.

[0043] Table 2 Proportions of soil conditioners used in each treatment in Example 2

[0044] Processing number Organic Fertilizer Mine soil pH 1 9.70％ 4 2 14.70％ 5 3 19.70％ 6

[0045] Observe plant height, leaf number, leaf color, leaf width, and tiller number every 7 days from the date of planting. Take the middle width of the third leaf near the stem base as the plant leaf width and record the data. Figure 3 and Figure 4 .

[0046] Example 3

[0047] The difference between this embodiment and embodiment 2 is that the addition ratio of the soil conditioner is shown in Table 3.

[0048] Table 3 Proportions of soil conditioners used in each treatment in Example 3

[0049] Processing number Organic fertilizer ratio lime 4 / 2.41％ 5 5％ 2.41％ 6 10％ 2.41％

[0050] Plant height, leaf number, leaf color, leaf width, and tiller number were observed every 7 days from the date of planting. The middle width of the third leaf near the stem base was taken as the plant leaf width, and the data were recorded as shown in Table 4.

[0051] Example 4

[0052] The difference between this embodiment and embodiment 2 is that the addition ratio of the soil conditioner is shown in Table 5.

[0053] Table 5 Proportions of soil conditioners used in each treatment in Example 4

[0054] Processing number Organic Fertilizer lime Conditioning Agents 7 2％ 2％ / 8 2％ 2％ 0.10％

[0055] Plant height, leaf number, leaf color, leaf width, and tiller number were observed every 7 days from the date of planting. The middle width of the third leaf near the stem base was taken as the plant leaf width, and the data were recorded as shown in Table 6.

[0056] Example 5

[0057] See also Figure 5 This embodiment provides a method for rapidly regreening acidic mine soil with energy plants, comprising the following steps:

[0058] S1, mine soil treatment: mark out a 30m×30m restoration area in the mine to be restored; evenly spread 2% lime, 2% organic fertilizer and 0.1% porous carbon powder conditioner on the exposed surface of the mine to be restored according to the soil volume weight ratio, use excavation equipment to plow and mix the top 30cm soil layer, and wait for vegetation to be planted after at least one month of rain leaching.

[0059] S2, making water-retaining matrix: crush grass, Miscanthus, shrubs, etc. into grass clippings of 5-8 cm, sprinkle with 0.2% stem decomposition agent and 0.5% urea, water thoroughly, cover with plastic film and let compost for 2 months for use. Pre-mix the composted grass clippings with yellow mud in a ratio of 2:1 on site to obtain a water-retaining matrix.

[0060] S3, Energy Plant Planting: Before planting vegetation, dig a planting hole with a row spacing of 1 meter, the hole depth is 30-40cm, and put in a volume of 1kg of water-retaining matrix. Cultivate seedlings with single-node cuttings of King Bamboo Grass, and transplant them when the seedling height and root length grow to 5cm. Be careful to remove the seedlings and try to avoid damaging the roots. Before planting, dip the roots in yellow mud with a water content of 80% to retain water. Plant one or two seedlings in the middle of the water-retaining matrix in the planting hole, that is, the grass clippings and mud mixture, and compact it. After watering thoroughly for planting and rooting, fill the topsoil and compact it into a nest shape to store water around the roots of the plants.

[0061] S4, sowing ground cover grass seeds to fully cover the ground surface: after planting the king grass, sow the seeds of Wedelia chrysantha that have been soaked and germinated to white in the treated area to be restored. In the non-rainy season, irrigate and water the plants on the site in real time to maintain the growth needs of the seedlings in the seedling stage.

[0062] S5, regularly harvest energy plants to make biomass raw materials: When the height of the grass plant grows to 2m, it can be harvested, then dried and crushed into grass of different specifications, which can be pressed into biomass pellet fuel for boiler combustion by biomass pellet machine, and the boiler ash can be used for heavy metal recovery or landfilled in the specified landfill. The remaining waste can also be used to make water-retaining matrix and returned to the area to be repaired to achieve the purpose of continuously improving the mine soil.

[0063] After half a year of ecological restoration, the root system of the king grass in the restoration area was well developed and enlarged, achieving the ecological and economic goals of restoring the soil, conserving water and soil, and producing energy biomass.

[0064] Comparative Example 1

[0065] This comparative example is the control group CK of Example 2, and the difference from Example 2 is that the mine soil is not treated, and then the king grass is transplanted, and the planting time is 90 days.

[0066] Observe plant height, leaf number, leaf color, leaf width, and tiller number every 7 days from the date of planting. Take the middle width of the third leaf near the stem base as the plant leaf width and record the data. Figure 3 .

[0067] Plant sample collection and index determination

[0068] Sample collection and processing: Plants were watered according to normal cultivation management and harvested after 90 days. The soil was first washed off with clean water, and then cleaned with deionized water. The samples were divided into underground parts (roots) and aboveground parts (stems and leaves). The plant height, number of tillers, number of leaves, fresh weight of aboveground parts and fresh weight of roots were recorded. Plant samples were dried in the shade and marked for testing. After the potted test, the soil samples were naturally dried in the shade and marked for testing.

[0069] Determination method: Soil physical and chemical properties were determined with reference to the "Soil Agricultural Chemical Analysis Method". Soil pH was determined using a Shanghai Lei-Magnetic precision pH meter (soil-water ratio 1:2.5), organic matter content was determined using the potassium dichromate method, and soil heavy metal Cr, Pb, and Cu contents were determined using HF-HClO4-HNO3 digestion followed by atomic absorption spectroscopy, also known as atomic absorption spectrophotometry.

[0070] The relevant tests were carried out on Example 2 and Comparative Example 1. The test results are shown in Figure 3 and Figure 4 .

[0071] Figure 3 The following is a comparison chart of the plant height, tillering and leaf number of King Bamboo Grass under different treatments in Comparative Example 1 and Example 2. Figure 3 It can be seen that the plants cannot grow in the mine soil without treatment and improvement, and all the king bamboo grass in comparative example 1 died. In Example 2, after adding organic fertilizer, the king bamboo grass can grow normally, and the plant height, tillering and leaf number are significantly increased with the increase of organic fertilizer dosage; compared with treatment 1 and treatment 2, the change increase of treatment 3 is the largest, and the king bamboo grass obtained in treatment 3 is much larger than the king bamboo grass obtained in treatment 1 and treatment 2 in terms of plant height, tillering and leaf number. Compared with treatment 1 and treatment 2, the difference in plant height is not large, but the number of tillers and leaves in treatment 2 is still significantly better than that in treatment 1. Specifically, the number of tillers in treatment 1 is 3 / 4 of that in treatment 2, and the number of leaves is 4 / 5 of that in treatment 2. It can be seen that mine soil has a significant inhibitory effect on the growth of king bamboo grass. The addition of organic fertilizer can effectively improve the mine soil and significantly improve the growth potential of king bamboo grass; the application amount of organic fertilizer adjusted to pH 6 has the best effect.

[0072] Figure 4 Schematic diagram of the biomass of King Grass under different organic fertilizer dosages in Example 2. Figure 4It can be seen that the aboveground fresh weight of the royal bamboo grass obtained in treatment 3 (pH6) is higher than that in treatment 1 (pH4) and treatment 2 (pH5). Specifically, the aboveground fresh weight of pH6 is 2.1 times that of pH4 and 1.24 times that of pH5; the aboveground fresh weight of pH5 is 1.7 times that of pH4. The underground fresh weight of royal bamboo grass obtained in pH6 is also higher than that of pH4 and pH5. Specifically, the underground fresh weight of pH6 is 3 times that of pH4 and 1.5 times that of pH5. The aboveground fresh weight and underground fresh weight increase significantly with the increase of organic fertilizer application, and the best effect is achieved when the pH value is 6 in treatment 3.

[0073] Relevant tests were performed on Example 3, and the test results are shown in Table 4.

[0074] Table 4 Growth of King Grass under different treatments in Example 3

[0075] Processing number Plant height / cm Tiller / pc Number of leaves / piece Fresh weight per plant / g 4 59.10±3.69b 4.00±0.58a 17.33±1.45a 5.14±0.32 5 85.80±0.95a 4.33±0.33a 21.00±1.52a 26.47±1.81 6 91.67±8.00a 3.00±1.15a 19.00±5.86a 35.38±2.13

[0076] Note: Lowercase letters in the table indicate significant differences among treatments (P<0.05).

[0077] Table 4 is a data table of the growth of King Bamboo Grass under different treatments in Example 3. Combining Table 3 and Table 4, it can be seen that King Bamboo Grass can grow normally under the three treatments. From the plant height data, the overall trend is Treatment 6>Treatment 5>Treatment 4, among which, the difference in plant height between Treatment 5 and Treatment 6 is not significant, and the difference in plant height between Treatment 4 and Treatment 5 is significant; the number of tillers and leaves of the three treatments are similar, with no significant difference. This shows that lime has a certain effect on improving soil and promoting plant growth, and the effect of adding lime and organic fertilizer at the same time is better than that of applying lime alone.

[0078] It is understandable that the pH value of mine soil is only 2.03, and there are a large number of free acids with complex components. It is extremely difficult for plants to grow in the mine acidic soil without any treatment, so soil conditioners must be added to increase the pH value and improve soil properties before plants can be planted. The results in Table 4 show that the application of lime alone can significantly improve the soil and increase the soil pH at the beginning, but as time goes by, the free acid in the lower layer of the soil is released and uploaded, causing its repair effect to gradually weaken, and frequent application of lime can easily cause the soil to become compacted or even acidified. Organic fertilizer contains alkaline substances, which can not only supplement soil humus for plant growth, but also effectively improve the physical structure of the soil. Therefore, while using lime to repair acidic soil, adding organic fertilizer, the two work synergistically to increase the content of soil organic matter, promote microbial reproduction, enhance soil buffering performance and enzyme activity, and help stabilize the acidic soil repair effect.

[0079] In addition, under the condition of meeting the nutrient requirements of plant growth, the application of organic fertilizer can be reduced to reduce costs, and it is more economical to use lime and organic fertilizer to improve the soil synergistically.

[0080] Relevant tests were performed on Example 4, and the test results are shown in Table 6.

[0081] Table 6 Growth of King Grass under different treatments in Example 4

[0082] Processing number Plant height / cm Tiller / pc Number of leaves / piece Fresh weight per plant / g 7 82.56±4.62 4.15±0.31 18.31±3.82 29.27±3.72 8 89.49±6.95 4.37±0.55 20.96±0.94 34.88±1.53

[0083] Table 6 is a data table of the growth of King Grass under different treatments in Example 4. Combining Table 5 and Table 6, it can be seen that the height of King Grass with the addition of conditioner is significantly higher than that of King Grass without the addition of conditioner. It can be understood that the conditioner is an alkaline substance with porous carbon powder as the main ingredient, rich in large and medium elements potassium, silicon and calcium required for plant growth; among them, silicon has the function of adjusting soil pH, improving acidic soil, reducing the activity of heavy metals, passivating and fixing soil heavy metals, and reducing the absorption of heavy metals by crops, thereby reducing the harmful effects of heavy metals. After the acidic polluted soil is neutralized with an appropriate amount of conditioner and the fertility of the soil is increased, the biomass of the repair plant can be increased to achieve a better repair effect. Combining Table 4 and Table 6, it can be seen that the growth data of energy plants in Treatment 6 and Treatment 8 are similar, indicating that the addition of conditioners can greatly reduce the amount of organic fertilizer used to save costs.

[0084] The present invention not only utilizes lime to repair acidic soil, but also applies organic fertilizer, and the two act synergistically, thereby increasing the content of soil organic matter, promoting microbial reproduction, enhancing soil buffering performance and enzyme activity, and helping to stabilize the acidic soil repair effect; adding a conditioner can effectively reduce the amount of organic fertilizer used, and reduce the cost of mine greening; and then planting king grass as an energy plant, which has wide adaptability, strong stress resistance, strong acid resistance, large biomass, high yield, and good greening effect.

[0085] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A method for rapidly regreening acidic mine soil with energy plants, characterized in that: Implement it by following these steps: S1, mine soil treatment: evenly spread the soil conditioner on the exposed surface of the mine to be repaired, use equipment to mix the surface soil layer with a thickness of 25 to 35 cm, and let rainwater leaching for at least one month before planting vegetation; S2, preparing a water-retaining matrix: composting grass clippings, and mixing the composted grass clippings with yellow mud in a certain proportion to obtain a water-retaining matrix; S3, Energy Plant Planting: Dig a planting hole and put in a water-retaining substrate, then cultivate the seedlings by cuttings, and transplant them into the planting hole when the seedling height and root length grow to more than 5cm. After watering thoroughly for planting and rooting, fill the topsoil and compact it into a nest shape to store water around the roots of the plants; S4, sowing ground cover grass seeds to fully cover the ground surface: after planting energy plants, sow ground cover grass seeds and irrigate and water the plants on site in real time during the non-rainy season.

2. The method for rapid regreening of acidic mine soil with energy plants according to claim 1, characterized in that: The soil conditioner is one or more of lime, organic fertilizer and conditioner.

3. The method for rapid regreening of acidic mine soil with energy plants according to claim 2, characterized in that: Calculated by volume weight ratio of 30cm soil in the surface layer, the soil improver includes 1-5% lime, 1-10% organic fertilizer and 0.05-0.2% conditioner in mass fraction.

4. The method for rapid regreening of acidic mine soil with energy plants according to claim 3, characterized in that: The soil conditioner comprises 2% lime, 5% organic fertilizer and 0.1% conditioner in mass fraction.

5. The method for rapid regreening of acidic mine soil with energy plants according to claim 2, characterized in that: The conditioning agent is an alkaline substance including porous carbon powder.

6. The method for rapid regreening of acidic mine soil with energy plants according to claim 5, characterized in that: The conditioning agent also includes potassium, silicon and calcium.

7. The method for rapid regreening of acidic mine soil with energy plants according to claim 1, characterized in that: In step S2, the step of composting the grass pieces is as follows: the harvested grass pieces are broken into grass clippings with a length of 5 to 8 cm, 0.1 to 1% of a stalk-degrading agent and 0.1 to 1% of urea are sprinkled into the pieces, the pieces are watered thoroughly, and the pieces are covered with a plastic film for composting.

8. The method for rapid regreening of acidic mine soil with energy plants according to claim 7, characterized in that: In step S2, the mass ratio of composted grass clippings to yellow mud is 2:

1.

9. The method for rapid regreening of acidic mine soil with energy plants according to claim 1, characterized in that: The energy plant is royal bamboo grass; the ground cover grass seeds are Wedelia chrysantha that has been soaked and germinated to become white.

10. The method for rapid regreening of acidic mine soil with energy plants according to claim 1, characterized in that: Also includes: S5, regularly harvest energy plants to make biomass raw materials: when the energy plants grow to 2m, they can be harvested and used to make water-retaining matrix or biomass pellet fuel; The boiler ash can be used to recover heavy metals or be landfilled in designated landfills.

Images