Ecological Restoration Methods of Borrow Sites

Abstract

The present invention discloses an ecological restoration method for a soil borrowing site, comprising: ① the first step of stripping the existing surface planting soil of the soil borrowing site and piling it for standby; ② excavating and taking soil in the soil borrowing site, shaping it into a slope structure with energy dissipation steps, and excavating drainage ditches around the soil borrowing site; ③ after the soil is taken, laying the stripped planting soil obtained in step 1 on the slope surface to form a planting soil layer for planting herbaceous plants and tree species maintained by plant nails; wherein the plant nails include pineapple-shaped plant nails for planting horizontal root type and composite root type tree species, and honeycomb coal-shaped plant nails for planting vertical root type tree species. The present invention is conducive to forming a root-soil complex with strong erosion resistance, and strengthening the slope protection and greening of the soil borrowing site.

Description

Technical Field

[0001] The invention relates to the technical field of ecological restoration of engineering construction, and in particular to an ecological restoration method for a soil borrowing site. Background Art

[0002] The soil excavation site is a bare excavation surface produced by engineering construction. The soil in the site is loose, and it is difficult for vegetation to survive and cannot be completely covered in a short period of time, resulting in serious soil erosion and ecological environment deterioration in the soil excavation site. ZL201410064680.3 A method for restoring the soil and water conservation ecology of a development and construction project improves the defect of poor soil by covering the surface with soil. However, due to the loose structure of the surface soil in the site, water and fertilizer leakage is not conducive to the growth of trees; CN200610017846.1 A plant seed tray is made of substrate, slow-release fertilizer and water. Seeds are sown in the seed tray and directly enter the slope that needs greening, which can make vegetation grow smoothly. However, it takes a long time for the plants cultivated by the above-mentioned seed tray to play a role in soil and water conservation, and the early ecological benefits are not obvious; in addition, for the conventional container planting method, the root system of the plant is prone to root entanglement, which affects the root system's soil-fixing effect. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for ecological restoration of a soil borrowing site, which can specifically adopt the following technical solutions:

[0004] The method for ecological restoration of a borrow pit according to the present invention comprises:

[0005] The first step is to strip off the existing surface planting soil in the soil borrowing area and pile it up for future use;

[0006] The second step is to excavate and take soil from the borrow area, shape it into a slope structure with energy dissipation steps, and dig drainage ditches around the borrow area;

[0007] Step 3: After the soil is taken, the stripped planting soil obtained in step 1 is laid on the slope surface to form a planting soil layer for planting herbaceous plants and tree species maintained by plant nails;

[0008] The plant nails include pineapple-shaped plant nails for planting horizontal root type and composite root type tree species, and honeycomb briquette-shaped plant nails for planting vertical root type tree species. By planting different types of trees in the planting layer, the shallow soil and deep root system can complement each other in the soil space distribution, and the staggered distribution can form a root network structure, thereby achieving the purpose of reinforcing the slope.

[0009] The pineapple-shaped plant nail comprises a first shell, a planting block is arranged at the bottom of the inner cavity of the first shell, a first planting area for filling with planting soil is arranged above the planting block, a convex structure is evenly distributed on the surface of the first shell opposite to the first planting area, and a root cutting hole is opened on the top of the convex structure. The above structure is conducive to the growth of fibrous roots.

[0010] The bottom surface diameter of the protruding structure is 3-5 cm, and the diameter of the root cutting hole is 1-2 cm.

[0011] The honeycomb briquette-shaped plant nail includes a second outer shell, which is an upper and lower opening structure, and the bottom edge of the second outer shell is connected to a planting tube arranged in its inner cavity, and the planting tube is a second planting area for filling with planting soil.

[0012] The planting block and the planting tube are both made of a mixture of nutrient soil, fertilizer and binder in a weight ratio of 80% to 82%, 15% to 18% and 2% to 5%.

[0013] The fertilizer is prepared by mixing a slow-release fertilizer and a microbial fertilizer in a weight ratio of 4 to 5:1.

[0014] The first shell and the second shell are both two-half combination structures, and the bottom edge of the first shell and the planting block, and the bottom edge of the second shell and the planting tube are both movable connection structures. It is convenient to disassemble the plastic shell and transplant the cultivated tree species to the soil borrowing site to avoid damage to the cultivated root system.

[0015] The horizontal root type and compound root type tree species and the vertical root type tree species in the planting soil layer are distributed alternately, and the spacing between the tree species is 3m; the herbaceous plants are arranged between the tree species.

[0016] The herbaceous plants include at least three herbaceous flowering plants, which are sown in equal proportions with a sowing density of 60g / kg to 85g / kg.

[0017] The ecological restoration method of the soil borrowing site provided by the present invention can solve the problems of poor greening effect and serious soil erosion in the existing soil borrowing site. Drainage ditches are set around the soil borrowing site, a planting soil layer is spread in the soil borrowing site, and herbaceous plants and tree species that have been maintained by plant nails are planted in the planting soil layer. The root systems of the above-mentioned tree species have different morphologies. As the plants grow, the developed roots in different directions in the site form a three-dimensional protective structure underground, which is conducive to forming a root-soil complex with strong erosion resistance, thereby strengthening the slope protection and greening of the soil borrowing site.

[0018] Compared with the prior art, the advantages of the present invention are as follows:

[0019] 1) Use plant nails to intervene in the root growth of tree species to a certain extent, so that the tree can better play the role of soil fixation by its root system after entering the soil borrowing area and give full play to its strengths. Set different plant nails at the foot, slope surface, and top of the engineering slope to improve the stability of the slope.

[0020] 2) The combination of tree species with horizontal root type, compound root type and vertical root type makes the shallow and deep root systems of plants distributed three-dimensionally in the slope soil layer, giving full play to the spatial complementary effect. The staggered distribution forms a network structure of the root system, and through mutual cooperation, the loose soil is formed into a stable root-soil complex.

[0021] 3) Herbaceous flowering plants are conducive to the migration of plant species, thereby promoting the succession and development of plant communities. As the plants grow, they will bring huge ecological benefits. Compared with traditional engineering measures, plant measures have the advantages of saving engineering costs and improving ecological benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the borrow pit described in the present invention.

[0023] Figure 2 yes Figure 1 Top view of the (various plants omitted).

[0024] Figure 3 yes Figure 1 Schematic diagram of the structure of the medium pineapple-shaped plant nail.

[0025] Figure 4 yes Figure 3 Top view of the plant (omitted planting soil and plants).

[0026] Figure 5 yes Figure 1 Schematic diagram of the structure of the medium honeycomb coal-shaped plant nail.

[0027] Figure 6 yes Figure 5 Top view of the plant (omitted planting soil and plants). DETAILED DESCRIPTION

[0028] The method for ecological restoration of a borrow pit according to the present invention comprises:

[0029] The first step is to strip off the existing surface planting soil in the soil borrowing area and pile it up for future use;

[0030] The second step is to excavate and take soil from the borrow area, shape it into a slope structure with energy dissipation steps, and dig drainage ditches around the borrow area;

[0031] Step 3: After the soil is taken, the stripped planting soil obtained in step 1 is laid on the slope surface to form a planting soil layer for planting herbaceous plants and tree species maintained by plant nails;

[0032] Among them, the plant nails include pineapple-shaped plant nails for planting horizontal root type and composite root type tree species, and honeycomb coal-shaped plant nails for planting vertical root type tree species.

[0033] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific construction process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0034] Example: River Regulation Project in North China

[0035] A river regulation project is located in a warm temperate continental monsoon climate area, with hot and rainy summers and cold and dry winters, with an average annual rainfall of 553.8 mm. The project area is mountainous and hilly, with brown soil and no obvious obstacles. The soil borrowing site is located on the terrace near the river bank of the project, covering an area of ​​0.6 hm2. 2 The original land type was forest and grassland, and the soil volume was 12,000 m 3 In order to improve the ecological environment of the borrow pit and reduce soil erosion, the ecological restoration method of the borrow pit described in the present invention is adopted.

[0036] First, the existing surface planting soil in the borrow site is stripped off and placed in the open space around the borrow site or on the side of the access road. Tree stumps are used to block the soil pile and the surface of the soil pile is covered with a dust-proof net for future use.

[0037] The stripping thickness of the above-mentioned surface planting soil is 30cm for forest land and 19cm for grassland. The original trees in the site are transplanted to the surrounding open space for greening, and the low shrubs and grasses and their roots are dug out together with the surface soil and piled on one side of the access road to the soil borrowing site for later use.

[0038] Then, if Figure 1 , 2 As shown, soil is excavated at the borrow site and shaped into a slope structure with a plurality of energy dissipation steps (two in this embodiment), and drainage ditches 1 are excavated upstream and on both sides of the borrow site, and the ends of the drainage ditches are connected to the energy dissipation pool.

[0039] After the soil is taken from the soil borrowing site, a certain thickness of stripped planting soil (the stripped planting soil is the spare soil obtained in step 1) is laid on the slope surface to form a planting soil layer 2 for planting herbaceous plants and tree species maintained by plant nails.

[0040] The plant nails for maintaining tree species include pineapple-shaped plant nails 3 for planting horizontal root type and composite root type tree species (see Figure 3 , 4), and honeycomb briquette-shaped plant spikes for planting vertical root tree species 4 (see Figure 5 , 6 ).

[0041] The pineapple-shaped plant nail 3 includes a first shell 31 made of PP plastic material, which is a cylinder with an upper and lower opening structure. A planting block 32 is installed at the bottom of the inner cavity of the first shell 31. The planting block 32 is made of a mixture of nutrient soil, fertilizer and binder (chlorate cement), wherein the nutrient soil, fertilizer and binder are in a ratio of 80% to 82%, 15% to 18%, and 2% to 5% (by weight), and the fertilizer is composed of a composite slow-release fertilizer and a phosphate bacterial fertilizer, and is in a ratio of 4 to 5:1 (by weight). Above the planting block 32 is a first planting area for filling with planting soil, and the planting soil is used to cultivate horizontal root type and composite root type tree species. The surface of the first shell 31 opposite to the first planting area is evenly distributed with raised structures 33, and a root cutting hole 34 is opened at the top of each raised structure 33. Usually, the diameter of the first shell 31 is 25 cm and the height is 20 cm; the outer diameter of the planting block 32 is adapted to the inner diameter of the first shell 31 and the height is 12 cm; the inner cavity of the first shell 31 above the planting block 32 is covered with planting soil, and 2 to 3 horizontal root or composite root tree species are sown 2 to 3 cm from the surface, and then covered with soil and compacted. After testing, the density of the planting block is greater than 1.4 g / m 3 , the planting soil density is 1.2~1.3g / m 3 . Cultivate it outdoors in a suitable environment for about a year, water it every three to four days in the first two months, and then water it two to three times a month. During the cultivation period, the seed roots grow to the raised structure 33 and come into contact with the air to form cut roots. The cut root holes can stimulate the growth of plant roots and form strong trees. In order to protect the cultivated tree roots, they are transplanted intact to the planting soil layer 2 of the soil excavation site. The first shell 31 adopts a two-half combination structure that can be separated radially, and the bottom edge of each first shell 31 and the planting block 32 adopt a snap-on active connection structure. When the root system is cultivated, open the first shell 31, and plant the internal planting soil, roots, and the planting block 32 below together into the planting soil layer 2 of the soil excavation site.

[0042] The honeycomb briquette-shaped plant nail 4 includes a second outer shell 41 and a planting tube 42 located in its inner cavity, wherein the second outer shell 41 is a cylindrical structure with a smooth outer wall and an upper and lower opening made of PP plastic, and the edge of its bottom is connected to the outer shell of the planting tube 42; the planting tube 42 is composed of a mixture of nutrient soil, fertilizer and binder (chlorate cement), wherein the nutrient soil, fertilizer and binder (chlorate cement) are in a ratio of 80% to 82%, 15% to 18%, and 2% to 5% (by weight), and the above-mentioned fertilizer is composed of a composite slow-release fertilizer and a phosphate bacterial fertilizer, and is in a ratio of 4 to 5:1 (by weight). Usually, the diameter of the second outer shell 41 is 20 cm and the height is 25 cm, and the thickness of the planting tube 42 is 7 cm; the inner cavity of the planting tube 42 is filled with planting soil, and 2 to 3 vertical tree species are sown 2 to 3 cm from the surface, and then covered with soil and compacted. After testing, the density of the planting tube is greater than 1.4g / m 3 , the planting soil density is 1.2~1.3g / m 3 . Cultivate it outdoors in a suitable environment for about a year, water it every three to four days in the first two months, and then water it two to three times a month. Its root system grows vertically downward along the planting tube 42 to form a sturdy vertical root tree. Similarly, in order to protect the cultivated tree roots, they are transplanted intact to the planting soil layer 2 of the soil borrowing site. The second outer shell 41 adopts a two-half combination structure that can be separated radially, and the bottom edge of each first outer shell 41 and the planting tube 42 adopt a snap-on active connection structure. When the root system cultivation is completed, open the first outer shell 41, and plant the internal planting tube 42 into the planting soil layer 2 of the soil borrowing site.

[0043] In the planting soil layer 2 of the soil borrowing site, the above-mentioned planting blocks 32 with horizontal root type or composite root type tree species and the planting tubes 42 with vertical tree species are evenly staggered in a plum blossom shape, and the spacing between adjacent plant blocks / planting tubes is preferably 3m. Horizontal root type or composite root type tree species include mountain peach, elm and other tree species, and vertical tree species include cypress, black pine and other tree species. Usually, vertical root type plant nails are planted on one side of the slope foot to play a certain blocking role; horizontal root type and composite root type tree species are planted near the lower slope to reduce water erosion.

[0044] The above-mentioned native tree species are planted in different plant nails according to their different root system forms. After a period of maintenance, the outer shells are removed and the plants grown on the plant nails are installed on the slope and top surface of the soil borrowing site, which can enable the plants to quickly play the role of soil reinforcement and soil and water conservation. The tree species maintained in the above-mentioned plant nails have a large number of lateral roots of horizontal root type and composite root type plants, and the roots are in an intact state during the transplanting process. In addition, as the plants grow, the developed roots in different directions in the site form a three-dimensional protective structure underground, which is conducive to the formation of a root-soil complex with strong erosion resistance and improves the ecological benefits of the soil borrowing site after use.

[0045] Furthermore, grass seeds are sown in the gaps between tree species for greening (i.e., herbaceous plants 5 are planted), and watering is carried out for 4 weeks. The above grass seeds are flowering herbs, including at least 3 kinds of herbaceous flowering plants (such as spiny thistle, small sedge, buttercup, etc.), mixed and sown in equal proportions, and the sowing density is 60g / kg~85g / kg. Since the vegetation succession process is related to pollinating organisms, increasing the species and number of pollinating plants can increase the probability of pollination, so that herbaceous plants 5 can be effectively migrated, and the succession of plant communities in the project area can be promoted.

[0046] While planting trees with plant nails, the same tree species were directly planted in the open space around the soil borrowing site as a control group experiment. After one year, the root system was dug out for observation, and it was found that the root length of Platycladus orientalis and Pinus thunbergii increased significantly, with an increase of 20.1%~24.6%. Compared with the control group, the number of lateral roots of horizontal root plants cultivated by pineapple-shaped plant nails 3 increased by 2.0~2.2 times that of the control group. The effects of air root cutting of pineapple-shaped plant nails on the number of lateral roots, total root length, and root volume indicators of different trees are shown in Table 1.

[0047] Table 1 Effects of plant nails on lateral root indexes of different trees

[0048]

[0049] In addition, according to statistics, in the method for ecological restoration of the soil borrowing site described in the present invention, the survival rate of trees is 100%, the surface soil protection rate of the soil borrowing site reaches 98%, and the vegetation coverage rate reaches 85%, with significant effects.

[0050] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

Claims

1. A method for ecological restoration of a borrow pit, characterized in that: include The first step is to strip off the existing surface planting soil in the soil borrowing area and pile it up for future use; The second step is to excavate and take soil from the borrow area, shape it into a slope structure with energy dissipation steps, and dig drainage ditches around the borrow area; Step 3: After the soil is taken, the stripped planting soil obtained in step 1 is laid on the slope surface to form a planting soil layer for planting herbaceous plants and tree species maintained by plant nails; The plant nails include pineapple-shaped plant nails for planting horizontal root type and composite root type tree species, and honeycomb coal-shaped plant nails for planting vertical root type tree species; The pineapple-shaped plant nail comprises a first shell, a planting block is arranged at the bottom of the inner cavity of the first shell, a first planting area for filling with planting soil is arranged above the planting block, a convex structure is evenly distributed on the surface of the first shell opposite to the first planting area, and a root cutting hole is opened on the top of the convex structure; The bottom surface diameter of the protruding structure is 3-5 cm, and the diameter of the root cutting hole is 1-2 cm; The honeycomb briquette-shaped plant nail comprises a second shell, the second shell is an upper and lower opening structure, and the bottom edge of the second shell is connected to a planting tube arranged in its inner cavity, and the planting tube is a second planting area for filling with planting soil; The planting block and the planting tube are both made of a mixture of nutrient soil, fertilizer and binder in a weight ratio of 80% to 82%, 15% to 18% and 2% to 5%; The fertilizer is a mixture of a slow-release fertilizer and a microbial fertilizer in a weight ratio of 4 to 5:1; The first shell and the second shell are both two-half combined structures, and the bottom edge of the first shell and the planting block, and the bottom edge of the second shell and the planting tube are both movable connection structures; The horizontal root type and compound root type tree species and the vertical root type tree species in the planting soil layer are staggered, and the spacing between the tree species is 3m; the herbaceous plants are arranged between the tree species; The herbaceous plants include at least three herbaceous flowering plants, which are sown in equal proportions with a sowing density of 60g / kg to 85g / kg.

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