CN103321195B - A kind of agricultural ecological interception irrigation canals and ditches and construction method thereof that adopts bulkhead tech - Google Patents

Abstract

The invention discloses a farmland ecological interception ditch adopting slope protection technology and a construction method thereof. The cross section of the ditch is an inverted trapezoid, the bottom of the ditch is a prefabricated perforated plate, the holes are arranged in an "S" staggered pattern, and local perennial aquatic plants are planted in the holes; after the soil body of the ditch is compacted, a three-dimensional plant net is laid on the soil and covered with a prefabricated perforated plate A number of holes are evenly and parallelly distributed in the upper part of the board, and bermudagrass and ryegrass are planted in the holes; grilles are set at the water inlet, and controllable drainage gates are set at the water outlet. Through the reasonable layout of the planting holes, and the use of the root system and the anchoring effect of the vegetation net to achieve the stability of the ditch structure. The ecological interception ditch of the present invention has a stable structure, and its structural stability can basically reach the structural strength of the concrete ditch for facility grain field construction, and can effectively resist the hydraulic erosion of farmland drainage, and at the same time can effectively intercept suspended solids and nitrogen in the drainage of farmland, especially dry land Phosphorus, etc.; and does not occupy arable land, the project cost is low, the operation is simple, and it is suitable for large-scale promotion and application.

Description

A farmland ecological interception ditch using slope protection technology and its construction method

technical field

The invention belongs to the technical field of agricultural non-point source pollution control, and specifically relates to a farmland ecological interception ditch which integrates the functions of preventing waterlogging and draining stagnation of farmland and the interception function of farmland runoff pollutants and adopts slope protection technology and a construction method thereof.

Background technique

In recent years, with the rapid development of modernization and intensification of planting production in my country, excessive and irrational use of farmland chemical fertilizers has become increasingly prominent in order to pursue high yields one-sidedly. The eutrophication of important water bodies such as Taihu Lake and Dianchi Lake caused by the loss of nitrogen and phosphorus nutrients getting worse. According to the Bulletin of the First National Survey of Pollution Sources released in 2010, agricultural non-point source pollution has become the main source of pollutants such as nitrogen and phosphorus in my country's water environment. Among them, with the strengthening of industrial point source pollution control in the Taihu Lake Basin, the proportion of agricultural non-point source pollution affecting the water environment quality of the basin is increasing. The contribution of total nitrogen is 34-52%, and the contribution of total phosphorus is 17-54%. %, becoming an important cause of eutrophication in the Taihu Lake Basin.

Domestic and foreign research on agricultural non-point source pollution control technology has produced various technical forms such as artificial wetlands, vegetation buffer zones, and multi-pond systems, which have the advantages of good ecological benefits and low operating costs. However, the above technologies all need to occupy a large area of cultivated land, and their promotion and application in many areas with a lot of people and little land in our country has been restricted. In the early 21st century, experts and scholars in our country started the research and application of ecological ditches, and achieved remarkable results in the research on the interception technology of farmland runoff pollutants. The slope is relatively large (>60°), and problems such as ditch wall collapse and aquatic plant death caused by hydraulic scouring are common in the later operation process, which leads to a great reduction in the purification efficiency of the ecological ditch.

Contents of the invention

The purpose of the present invention is: according to the characteristics of non-point source pollution produced by the planting industry, aiming at the problems of poor structural stability in the process of constructing ecological ditches in the past, to provide a structure that meets the requirements of structural strength and integrates the function of preventing waterlogging and drainage of farmland and polluting farmland runoff. Integrating the interception function of objects, the farmland ecological interception ditch and its construction method using slope protection technology.

The idea of the present invention is to apply the three-dimensional plant network slope protection technology to the construction of ecological interception ditches in combination with the current construction status of farmland drainage ditches in our country, and to rationally lay out the ditches according to the hydraulic and engineering mechanics characteristics of the ditch drainage system. The planting hole utilizes the anchoring effect between the root system and the three-dimensional plant net to achieve the stability of the ditch structure, and then give full play to its ecological purification function.

Technical scheme of the present invention is as follows:

A farmland ecological interception ditch adopting slope protection technology. The water inlet end of the ditch is equipped with a coarse grid, and the water outlet end is equipped with a controllable drainage gate. Aquatic plants are planted in the hole of the porous plate at the bottom of the ditch and on the wall of the ditch; it is characterized in that: the wall of the ditch is under the prefabricated perforated plate, and a layer of three-dimensional plant net is laid close to the compacted soil; the holes on the prefabricated perforated plate at the bottom of the ditch are Arranged in an "S" shape.

Preferred solution:

The cross-sectional size of the ditch body is preferred: the upper width is 1.5m, the lower width is 0.5m, and the ditch depth is 1.0m; the superelevation (that is, the height of the corridor at the top of the ditch beyond the farmland surface) is preferably 0.2m.

The opening method of the prefabricated slab is as follows: the bottom plate of the ditch adopts the "S" type staggered opening method; Holes are opened in parallel and evenly distributed holes.

The prefabricated slab at the bottom of the ditch is rectangular, with a size of 500mm×1200mm and a thickness of 40mm, and steel mesh is laid inside it; five circular holes (D150mm) arranged in an "S" shape are set on a single ditch bottom slab.

The prefabricated panel of the ditch wall is rectangular, with a size of 600mm×1200mm and a thickness of 40mm, and steel mesh is laid inside it; 12 parallel and evenly distributed circular holes (D100mm) are set on a single ditch wall panel.

At the top of the prefabricated slab on the ditch wall, there is a part where the steel bar exceeds the concrete. During construction, the protruding part of the top steel bar extends into the interior of the corridor pressure roof at the top of the ditch wall.

The model of the three-dimensional plant net is preferably EM2, with a width of 1.0m. A part (about 100mm) of the upper end of the three-dimensional plant net 3 extends under the roof of the corridor at the top of the ditch wall.

The aquatic plants in the hole are local perennial aquatic plant species, with a large amount of plants and high demand for nitrogen and phosphorus nutrients.

The inlet end of the ditch is equipped with a plate-type coarse grille, and the outlet end is equipped with a controllable drainage gate; the grille is placed at the farmland drain to filter large suspended solids, weed roots, etc.; the controllable drainage gate is equipped with gates of various heights , manually controlled according to the seasonal drainage characteristics of the farmland. In addition, according to the actual needs of serving farmland, auxiliary facilities such as aisle slabs, ditch bottom overflow weirs, and coarse grilles can be installed.

In the present invention, the cross-sectional size of the ditch is designed according to the characteristics of farmland drainage and engineering structure mechanics. The preferred size is: upper width 1.5m, lower width 0.5m and ditch depth 1.0m, that is, to ensure that the ditch can fully exert the function of waterlogging prevention and drainage. , significantly increasing its structural stability and service life, the design idea is as follows:

(1) Groove depth

According to the design requirements of drainage ditches in our country, referring to the experience of past farmland water conservancy facilities construction, the stagnant drainage project should meet the maximum drainage depth required for the whole growth period of crops as the engineering control standard, and the rice cultivation area is in the drying period of 3 to 10 years. Within 5 days, the buried depth of groundwater shall be reduced to 0.4-0.6m. Therefore, in combination with the distance between ditches (100-250m) in the fields in Shanghai, the ditches should be flat-bottomed. According to the gradient of water flow, the stagnation depth is 0.6m, the daily water depth is 0.1-0.2m, and the superelevation is 0.2m, so the ditch depth is determined to be 1.0m. .

(2) Cross-sectional size

The planned and designed ecological ditches are dual-purpose for drainage and waterlogging, and the cross-sectional size is checked according to the design flow of waterlogging drainage. The waterlogging function of the present invention meets the requirement of 1-3d rainstorm once in 10 years and 3-5d drainage to the flood-resistant water depth. The 1-day rainfall that occurs once every 10 years in Shanghai is about 176mm, and the design modulus of waterlogging is 2.0m ³ /km ² .s. Under this flow rate, the flow rate should meet the requirements of no flushing and no silting.

The minimum width of the canal bottom is generally 0.5m, and when the slope coefficient is 0.25, the upper width is 1m, checked according to the flow rate, and the flow rate can meet the specification requirements. However, considering the channel volume occupied by aquatic plants in the ecological interception ditch and local customary practices, the slope coefficient is appropriately enlarged, and the slope coefficient of the ecological interception ditch is taken as 0.4. In summary, the cross-section of the designed ecological interception ditch is inverted trapezoidal, and the cross-sectional dimensions are: the depth of the ditch is 1.0m, the bottom width is 0.5m, and the top width is 1.5m.

In addition, prefabricated slab specifications, concrete grades, and steel bar models can be reasonably selected in combination with the actual project. The selection of prefabricated slab specifications mainly considers the structural strength and convenience of construction, but the thickness cannot be reduced (that is, the thickness of the prefabricated slab at the bottom and wall of the ditch should not be less than 40mm). The selection of hole shape and size also mainly takes into account the production cost and soil fixing ability. When planting different aquatic plants, the hole diameter can be set empirically according to the size of the plants. In view of the impact of the opening of the hole on the structure of the cement board, the classic circular hole with the largest specific area is preferred.

The basis for determining the size of the ditch in the present invention is mainly to meet the requirements of drainage and stagnation prevention, while the method for designing structural stability is mainly the way of opening holes and the laying of three-dimensional plant nets. The design of the entire ecological ditch should be carried out in accordance with such a main line: firstly, to meet the drainage requirements: determine the section size; secondly, consider stability: opening methods, laying plant nets, etc.; thirdly, consider ecology: "S" type planting of aquatic plants at the bottom of the ditch , plant species, plant spacing and other parameters selection.

A method of constructing a farmland ecological interception ditch using slope protection technology: firstly, according to the requirements for drainage and stagnation prevention, the characteristics of farmland drainage and the mechanical design of the engineering structure, the cross-sectional size of the ditch is determined, and the ditch is repaired or newly opened. Set up grilles, and set controllable drainage gates at the water outlet; secondly, consider the stability of the ditch: on the basis of compacted soil, lay a layer of three-dimensional plant nets on the ditch walls, and cover the three-dimensional plant nets with prefabricated perforated plates; The bottom plate adopts the "S" type staggered opening method to open holes; the groove wall plate reserves a certain height (about 0.45m from the bottom) at the bottom without opening holes, and the part above 0.45m from the bottom adopts the method of parallel and evenly distributed holes; The third consideration is the ecology of the ditch: plant local perennial aquatic plants with a large amount of plants and a large demand for nitrogen and phosphorus in the holes arranged in an "S" shape on the bottom of the ditch; plant.

The above-mentioned method specifically comprises the steps:

(1) Determine the optimal size of the cross-section of the ditch body: the upper width is 1.5m, the lower width is 0.5m, the ditch depth is 1.0m, and the super height is preferably 0.2m; the ditch body is refurbished or newly opened according to the size, and plains are poured at the lower ends of both sides of the ditch bottom concrete cushion;

(2) Calculate and purchase the required three-dimensional plant net according to the length of the ditch and the total area on both sides of the ditch wall;

(3) Custom-made prefabricated panels at the bottom of the trench, preferably: rectangular, 500mm×1200mm in size, 40mm thick, with steel mesh laid inside, and 5 circular holes (D150mm) arranged in an "S" shape on the panel; custom-made trench walls Prefabricated slabs, preferably: rectangular, with a size of 600mm×1200mm and a thickness of 40mm, laying steel mesh inside, and a section of steel bar is reserved at the top for connection with the roof of the corridor, and 12 parallel and evenly distributed circles are divided at the part above 0.45m from the bottom Shaped hole (D100mm);

(4) Lay a layer of three-dimensional plant net on the ditch wall on the basis of compacted soil, and a part (about 100mm) of the top of the three-dimensional plant net extends into the corridor at the top of the ditch wall;

(5) Lay prefabricated perforated panels on the ditch wall on the three-dimensional plant net, and place the bottom of the ditch wall on the plain concrete cushion; Cement is poured on the corridor to form the corridor roof, and the steel bars reserved at the top of the ditch wall plate extend into the interior of the corridor roof; (the excess part of the top of the three-dimensional plant net extends below the corridor roof;)

(6) Lay the prefabricated perforated slab at the bottom of the ditch, and a small section of the lower end of the prefabricated slab on the ditch wall is under the bottom of the ditch;

(7) Plant water bamboo or yellow calamus in the holes arranged in an "S" shape on the bottom of the ditch; plant bermudagrass in the parallel and evenly distributed holes on the wall of the ditch by transplanting turf, and re-sow ryegrass in winter.

The present invention carries out corresponding engineering transformation on the basis of the original "full concrete prefabricated slab" type and simple soil ditch, so that it has both drainage and ecological functions. Through the application of the three-dimensional plant net slope protection technology and the reasonable setting of the prefabricated slab holes on the ditch bottom and ditch wall, the anchorage between the root system and the plant net is used to enhance its structural stability, and the firmness is close to the requirements of concrete ditches for the construction of facility grain fields. Local perennial aquatic plants are planted in the bottom plate holes, and the roots can form a good oxygen secretion system to enhance microbial activities, and then remove pollutants such as nitrogen and phosphorus in the runoff through interception, adsorption, and absorption.

In order to slow down the flow rate of farmland runoff drainage and increase its hydraulic retention time in the channel, the present invention utilizes the principle of corridors in sewage treatment technology, and the bottom plate holes are arranged in an "S" staggered pattern. Through the "S" layout of the bottom plate holes, after the aquatic plants reach the mature stage, the precipitation of particulate matter can be effectively promoted through the blocking effect of the plants, thereby greatly increasing the removal of adsorbed nitrogen and phosphorus, and effectively cooperating with the oxygen secretion system of the plant roots Adsorption, absorption, aerobic and anaerobic effects. In addition, a reasonable allocation of aquatic plants on the wall and bottom of the ditch can also form a good ecological landscape, and can generate corresponding economic benefits according to different species.

Beneficial effects of the present invention:

The invention is a farmland ecological interception ditch adopting the slope protection technology, the stability of the ditch body structure can basically reach the structural strength of the concrete ditch for the construction of the facility grain field, and at the same time, it can effectively intercept the suspended solids, nitrogen and phosphorus in the drainage of the farmland, especially the dry land. The invention has the advantages of stable structure, good pollutant interception effect, low engineering cost and maintenance cost, good landscape effect, etc., and has good popularization and application value.

The present invention adopts the slope protection technology for farmland ecological interception ditches, which has the following characteristics: first, the structure is relatively stable, which can effectively resist the hydraulic erosion caused by rainfall and the drainage of the lower part of the ditch, thereby greatly reducing the maintenance and management costs in the later stage; second, the runoff drainage pollution matter can play an effective interception role, the interception rate of nitrogen is about 45-55%, the interception rate of phosphorus is 50-65%, especially for particulate matter (SS) in water, the interception rate can reach more than 90%; the third is because the invention It is based on the reconstruction of the original farmland ditches, and achieves the purpose of not occupying cultivated land. The project cost is low and the operation is simple. It is especially suitable for large-scale promotion and application in the Taihu Lake Basin and even the river network areas in the eastern plains of my country.

Description of drawings

Fig. 1 is the cross-sectional schematic diagram of farmland ecological interception ditch of the present invention;

Fig. 2 is the structural representation of the ditch floor of the farmland ecological interception ditch of the present invention;

Fig. 3 is the schematic diagram of the ditch wall plate structure of farmland ecological interception ditch of the present invention;

Fig. 4 is the schematic diagram of the corridor topping of the farmland ecological interception ditch of the present invention;

Fig. 5 is the schematic diagram of the water outlet controllable ram of the farmland ecological interception ditch of the present invention;

Fig. 6 is a cross-sectional effect diagram of the farmland ecological interception ditch of the present invention.

In the figure: 1, ditch wall board 2, ditch bottom board 3, three-dimensional plant net 4, drainage gate 5, steel mesh 6, reinforcement bar top part of ditch wall board 7, corridor top pressure 8, field surface 9, plain concrete cushion 10, Farmland soil 11, rammed soil 12, circular hole

detailed description

Example 1

The application test project is located in Jinghua Village, Liantang Town, Qingpu District, Shanghai (E120.998°, N30.963°). The matching farmland is rice field, and the degree of non-point source pollution is relatively serious, and the original drainage ditch is a simple soil ditch. There are outstanding problems such as poor drainage and difficulty in drying the fields. Therefore, based on the requirements of farmland drainage and waterlogging prevention in the Qingxi area of the upper reaches of the Huangpu River, according to the technical parameters provided by this design, it will be transformed into a farmland ecological interception ditch with both waterlogging prevention and drainage functions and ecological interception functions.

As shown in Figure 1, the cross-section of the farmland ecological interception ditch is an inverted trapezoid, and the ditch wall 1 and ditch bottom 2 on both sides are prefabricated porous plates, and a layer of three-dimensional plant net is added between the ditch wall and the soil 3. To reduce the damage caused by hydraulic erosion and enhance the structural stability of the ditch. The cross-sectional dimensions of the ditch body are: upper width 1.5m, lower width 0.5m, ditch depth 1.0m, super height 0.2m (that is, the height of the corridor top 7 at the top of the ditch beyond the farmland surface 8). The model of the three-dimensional plant net is EM2, with a width of 1.0m. When the three-dimensional plant net 3 is laid, a part (about 100 mm) of its upper end extends into the corridor top 7 at the top of the ditch wall.

As shown in Figure 2, the prefabricated slab at the bottom of the trench is rectangular, made of concrete (C20), the size is 500mm×1200mm, and the thickness of the slab is 40mm. HPB300 grade hot-rolled steel mesh (Φ4mm) is laid inside it. The circular bottom plate holes on the ditch bottom plate are arranged in an "S" shape, and five circular holes 12 (D150mm) are set on the single plate. Water bamboo is planted in the holes. This plant has the advantages of large plant volume and high nitrogen and phosphorus absorption and utilization efficiency.

As shown in Figure 3, the prefabricated slab of the ditch wall is rectangular, made of concrete (C20), the size is 600mm×1200mm, and the thickness of the slab is 40mm. HPB300 grade hot-rolled steel mesh (Φ4mm) is laid inside it. The part of the ditch wall plate above 0.45m from the bottom adopts the method of parallel and evenly distributed holes, and the single plate is provided with 12 circular holes (D100mm). During construction, a section of the lower end of the ditch wall plate near the bottom must go deep under the ditch floor, as shown in Figure 1. The bottom of the ditch wall board rests on the plain concrete cushion 9, and the vertical distance between the hole in the bottom layer of the ditch wall board and the bottom of the ditch is 0.25m after the construction is completed. In the circular hole 12 from the bottom of the ditch wall board, bermudagrass is planted by turf transplantation, and ryegrass is re-sowed in winter.

As shown in Fig. 3 and Fig. 4, there is a section of reinforcement at the top of the ditch wall that exceeds the length of the concrete by about 100mm.

As shown in Figure 5, manually controllable drainage gates 4 with different water levels are set at the outlet of the ditch to control the residence time of farmland runoff drainage in the ecological interception ditch during different rainfall periods, and the operation is simple and easy to promote.

In addition, a plate-type coarse grille with a size of 500mm×900mm is installed at the water inlet end of the ecological interception ditch. In addition, other auxiliary facilities such as aisle slabs and overflow weirs at the bottom of the ditch have been set up.

This embodiment applies the farmland ecological interception ditch of the present invention to achieve the following effects: 1. The structure is relatively stable, which can effectively resist the hydraulic erosion caused by rainfall and the drainage of the lower part of the ditch, greatly reducing the maintenance and management costs in the later stage; To achieve effective interception, the pollutant content of farmland drainage varies greatly according to different crop growth periods. The interception rate of nitrogen is 45-55%, and the interception rate of phosphorus is 50-65%. However, the interception rate of particulate matter (SS) in drainage The rate can reach more than 90%; the third is based on the reconstruction of the original farmland ditches to achieve the purpose of not occupying the cultivated land, the project cost is low, and the operation is simple.

Example 2

The application test project is located in Shanghai Qingpu Modern Agricultural Park (E121.029°, N30.966°), the matching farmland is rice field, the degree of non-point source pollution is relatively serious, and the original drainage ditch is "three-sided light" with serious damage All concrete ditches, no ecological purification function. Therefore, based on the requirements of farmland drainage and waterlogging prevention in the Qingxi area of the upper reaches of the Huangpu River, according to the technical parameters provided by this design, it will be transformed into a farmland ecological interception ditch with both waterlogging prevention and drainage and ecological interception functions.

As shown in Figure 1, the cross-section of the farmland ecological interception ditch is an inverted trapezoid, and the ditch wall 1 and ditch bottom 2 on both sides are prefabricated porous plates, and a layer of three-dimensional plant net is added between the ditch wall and the soil 3. To enhance the stability of the ditch body. The cross-sectional dimensions of the ditch are: upper width 1.5m, lower width 0.5m, ditch depth 1.0m, super height 0.15m. The three-dimensional plant net model is EM3, and the upper end of the wide 1.0m three-dimensional plant net 3 has a part (about 100mm) stretching into the gallery top 7 below the ditch wall top.

As shown in Fig. 2, Fig. 3 and Fig. 4, the material, size and laying method of the ditch bottom and ditch wall prefabricated slabs, as well as the opening mode, number of holes and sizes on the board are the same as in Example 1. The "S"-shaped circular holes on the bottom of the ditch are arranged in a staggered manner. Iris is planted in the holes, which has the advantages of large plant volume, large nitrogen and phosphorus absorption, and good landscape effects. Parallel and uniform circular holes are distributed on the middle and upper part of the ditch wall (more than 0.45m from the bottom). Bermudagrass is planted by turf transplantation, and ryegrass is re-sown in winter.

As shown in Figure 5, a plate-type coarse grille with a size of 500 mm × 920 mm is installed at the water inlet end of the ecological interception ditch, and a manual controllable drainage gate 4 with different water levels is installed at the water outlet end. Bottom overflow weir and other auxiliary facilities.

This embodiment applies the farmland ecological interception ditch of the present invention to achieve the following effects: 1. The structure is relatively stable, which can effectively resist hydraulic erosion, thereby greatly reducing the maintenance and management costs in the later stage; 2. It can effectively intercept runoff drainage pollutants, The content of pollutants in farmland drainage varies greatly depending on the growing season of the crops. The interception rate of nitrogen is 45-55%, that of phosphorus is 50-65%, but the interception rate of particulate matter (SS) can reach more than 90%; 3. Based on the reconstruction of the original farmland ditches, the purpose of not occupying the cultivated land is achieved, the project cost is low, and the operation is simple.

Claims (10)

1. agricultural ecological interception irrigation canals and ditches that adopt bulkhead tech, the water inlet end of irrigation canals and ditches is provided with grid, and water side is provided with controlled rowSluice gate, ditch body cross section is inverted trapezoidal, it is characterized in that: it is to transform and form on the basis of original simple and easy soil property irrigation canals and ditches;Bottom of trench and furrow bank have all been laid Prefabricated porous plate, in the porous plate hole of bottom of trench, furrow bank both sides, have planted water plant; Furrow bank twoSide, below Prefabricated porous plate, is also close to the compacting soil body and has been laid one deck three-dimensional plant net; Utilize the gallery in sewage disposal technologyPrinciple, the hole on bottom of trench Prefabricated porous plate adopts " S " type to be laid staggeredly; Furrow bank Prefabricated porous plate is reserved one section highly not in bottomPerforate, on it, part adopts the mode perforate of parallel uniform hole; In the porous plate hole of bottom of trench, furrow bank both sides, plantation is aquaticPlant, select phytomass large, to the perennial water plant in the large this locality of demanding volume of nitrogen and phosphorus.

2. the agricultural ecological of employing bulkhead tech as claimed in claim 1 interception irrigation canals and ditches, is characterized in that: described ditch body is cross-sectionFace is of a size of: upper wide 1.5m, lower wide 0.5m, ditch depth 1.0m.

3. the agricultural ecological of employing bulkhead tech as claimed in claim 1 or 2 interception irrigation canals and ditches, is characterized in that: bottom of trench, ditchWall prefabricated board thickness is all not less than 40mm, lays bar-mat reinforcement in it; Furrow bank Prefabricated porous plate is apart from the above part of bottom 0.45mAdopt parallel equal mode for cloth perforate.

4. the agricultural ecological of employing bulkhead tech as claimed in claim 3 interception irrigation canals and ditches, is characterized in that: furrow bank prefabricated board topEnd has one section of reinforcing bar to exceed part to stretch into the gallery inside of bearing down on one; There are a bit of going deep into below trench floor, furrow bank in furrow bank prefabricated board lower endPlate bottom is placed on the plain concrete bed course below trench floor; The gallery that three-dimensional plant holds some to stretch into furrow bank top on the net bears down on oneBelow.

5. the agricultural ecological of employing bulkhead tech as claimed in claim 4 interception irrigation canals and ditches, is characterized in that: in trench floor holeThe perennial water plant wild rice stem in this locality or yellow flag that planting plants amount is large, demanding volume of nitrogen and phosphorus is large; Furrow bank plate holes adopts turf to moveThe mode of planting is planted bermudagrass grass, the rye grass of replaying winter.

6. the agricultural ecological of employing bulkhead tech as claimed in claim 5 interception irrigation canals and ditches, is characterized in that: bottom of trench prefabricated board isRectangle, is of a size of 500mm × 1200mm; Furrow bank prefabricated board is rectangle, is of a size of 600mm × 1200mm.

7. the agricultural ecological of employing bulkhead tech as claimed in claim 6 interception irrigation canals and ditches, is characterized in that: on monolithic trench floorArrange 5 and be the circular opening that " S " type is laid, each Circularhole diameter is 150mm; On monolithic ditch wallboard, arrange 12 parallel allThe circular opening of cloth, each Circularhole diameter is 100mm.

8. the agricultural ecological of employing bulkhead tech as claimed in claim 7 interception irrigation canals and ditches, is characterized in that: three-dimensional plant net typeNumber be EM2; The grid of the water inlet end setting of irrigation canals and ditches is board plug type coarse rack.

9. a construction method for the agricultural ecological interception irrigation canals and ditches of the employing bulkhead tech as described in as arbitrary in claim 1-8, its spyLevy and be: first according to the anti-stagnant requirement of water drainage and local agricultural drain feature, determine the cross sectional dimensions of irrigation canals and ditches, rebuild or newly openDitch body, arranges grid at the water inlet end of irrigation canals and ditches, and water side arranges controlled emptying gate; Secondly want according to the design of engineering structure mechanicsPoint, guarantees the steadiness of ditch body: furrow bank, on the basis of soil body compacting, is adjacent to and lays one deck three-dimensional plant net, at three-dimensional plantAdd a cover Prefabricated porous plate on the net; Utilize the gallery principle in sewage disposal technology, trench floor adopts the staggered perforate mode perforate of " S " type;Ditch wallboard is reserved one section of highly not perforate in bottom, and on it, above part adopts the perforate of parallel uniform hole mode; The 3rd considers ditchThe ecological property of canal: be this locality unboiled water for many years that in the hole of " S " type arrangement, planting plants amount is large, demanding volume of nitrogen and phosphorus is large on trench floorRaw plant; Planting aquatic plants in parallel uniform hole on ditch wallboard.

10. the construction method of the agricultural ecological of employing bulkhead tech as claimed in claim 9 interception irrigation canals and ditches, is characterized in that:Comprise the steps:

(1) determine that ditch body cross dimension is: upper wide 1.5m, lower wide 0.5m, ditch depth 1.0m; Rebuild or newly ditch by sizeBody, and build plain concrete bed course in lower end, bottom of trench both sides;

(2), according to irrigation canals and ditches length and the furrow bank both sides gross area, calculate and buy required three-dimensional plant net E2;

(3) bottom of trench prefabricated board customized: rectangle, be of a size of 500mm × 1200mm, thickness of slab 40mm, lays reinforcing bar in itNet, opens 5 and is the circular opening diameter 150mm that " S " type is laid on plate; Furrow bank prefabricated board customized: rectangle, is of a size of600mm × 1200mm, thickness of slab 40mm, lays bar-mat reinforcement in it, and the reserved one section of reinforcing bar in top bears down on one and is connected use with gallery,Apart from separately 12 parallel uniform circular opening diameter 100mm of the above portion of bottom 0.45m;

(4) furrow bank, on the basis of soil body compacting, is adjacent to and lays one deck three-dimensional plant net, and three-dimensional plant holds some to stretch on the netEnter on the gallery at furrow bank top;

(5), at the online bedding furrow bank of three-dimensional plant Prefabricated porous plate, ditch wallboard bottom is placed on plain concrete bed course; Ditch wallboard top is pre-The reinforcing bar staying stretches on the gallery on the ditch ridge, and lays vertical reinforcement, then at gallery upper cement, forms gallery and bears down on one, ditchThe reserved reinforcing bar in wallboard top stretches into the gallery inside of bearing down on one;

(6) lay bottom of trench Prefabricated porous plate at bottom of trench, furrow bank prefabricated board lower end has a bit of below trench floor;

(7) on trench floor, be in the hole that " S " type arranges and plant wild rice stem or yellow flag; Parallel uniform hole on ditch wallboardInterior employing turf transplanting mode plantation bermudagrass grass, the rye grass of replaying winter.