A method for stabilizing slopes by using plants in drainage ditches in saline-alkali land

Abstract

The invention provides a saline-alkali land drainage ditch plant slope fixing method, which belongs to the technical field of plant slope fixing, and comprises the following steps: S1, constructing ridges and ditches: in spring or autumn, digging ridges and ditches on the slope surface of the drainage ditch, 45-55 cm above the highest water level, and building a ridge every 30-40 m; S2, irrigating and pressurizing salt water: before planting, irrigating and pressurizing salt water into the ridges and ditches; S3, selecting plant varieties: selecting tamarisk and weeping willow as planting seedlings; S4, digging planting holes: when the ridges and ditches are dry and the soil is not too sticky to the shovel, digging planting holes; S5, transplanting: transplanting weeping willows and tamarisks alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is ≤3 days; S6, irrigating seedling protection water; irrigating seedling protection water in time after transplanting, and irrigating thoroughly; S7, management and maintenance; the invention adopts the method of planting weeping willows and tamarisks on the slope of the drainage ditch, and using the plant root system to protect the slope of the drainage ditch, and the slope protection effect is remarkable.

Description

Technical Field

[0001] The invention relates to the technical field of plant slope stabilization, and in particular to a method for plant slope stabilization in a saline-alkali land drainage ditch. Background Art

[0002] Drainage ditch refers to the ditch that leads the water collected in the side ditch, intercepting ditch and low-lying areas near the roadbed, crop fields and houses to the outside of the roadbed, crop fields and houses; in the prior art, due to the high groundwater level, especially in areas with high groundwater mineralization, in order to prevent land salinization, the groundwater level must be controlled through drainage ditches, and groundwater above the critical water depth must be infiltrated into the drainage ditch and discharged into the receiving area through the drainage ditch to ensure that the groundwater level on both sides of the drainage ditch does not exceed the critical water depth, thereby achieving the purpose of preventing soil salinization; groundwater infiltrates into the drainage ditch from the slope of the drainage ditch. During the infiltration, the soil at the infiltration point will reach a saturated state. If the slope is steep or the amount of water is large, the soil at the infiltration point will be washed into the drainage ditch, causing slope collapse.

[0003] Research has shown that the most vulnerable area to collapse is 30-50 cm above the highest water level in the drainage ditch. In the prior art, a more effective way to avoid collapse in the drainage ditch is to increase the width of the opening to reduce the slope. However, this not only increases the amount of earth excavation, but also occupies a large amount of land. For this reason, innovative experiments have been conducted such as using the "coarse sand replacement method" in areas prone to collapse to increase permeability to reduce collapse. However, these experiments have not been widely promoted due to the large amount of work and high cost. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for fixing the slope of a drainage ditch in saline-alkali land by planting salt-tolerant and suitable trees and shrubs such as tamarisk and weeping willow alternately and at intervals 45-55 cm above the highest water level of the drainage ditch, and using the roots of the trees and shrubs to prevent the soil from being carried away by the water infiltrating into the drainage ditch, thereby playing the role of fixing the soil and protecting the slope. The salt-tolerant trees and shrubs are planted alternately and at intervals, which not only improves the survival rate, but also improves the drainage ditch landscape and the growth environment of saline-alkali land plants. The details are as follows:

[0005] A saline-alkali land drainage ditch plant slope stabilization method comprises the following steps:

[0006] S1. Construction of ridges: In spring or autumn, dig a 45-55cm wide ridge 45-55cm high on the slope of the drainage ditch 45-55cm above the highest water level, and build a ridge every 30-40m along the ridge;

[0007] S2. Irrigation and pressure-salt water: Before planting, irrigate the ridges and ditches with pressure-salt water; Before planting, irrigate the ridges and ditches with pressure-salt water. Try to irrigate as much as possible without "running, bubbling, or exposing". If irrigating on ridges, make sure to make sure the openings are well-drilled after irrigating and the ridges are firmly built.

[0008] S3. Plant variety selection: Select Tamarix and Salix babylonica as planting seedlings; Tamarix is ​​a salt-secreting plant with strong salt tolerance and high survival rate. It can reduce the soil salt content in the root layer of plants and reduce the salt persecution of neighboring Salix babylonica, which is beneficial to improve the survival rate of Salix babylonica; Salix babylonica belongs to the tree category, with high trunk, large crown and obvious sunshade effect. Although its salt tolerance is weaker than that of Tamarix, its sunshade effect can reduce the evaporation of soil moisture, thereby reducing the surface accumulation of salt and inhibiting the return of soil salt; the two work together to reduce the surface salt accumulation while promoting each other's growth; moreover, Salix babylonica and Tamarix babylonica are very cold-resistant, heat-resistant and wind-sand-resistant, and are suitable for a wide range of planting;

[0009] S4. Dig planting holes: When the soil in the furrow is dry and not sticky enough to the shovel, dig planting holes;

[0010] S5, transplanting: transplanting the weeping willows and tamarisks prepared in step S3 alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is ≤ 3 days, and it is best to plant them as they are dug;

[0011] S6. Irrigation for seedling protection: Irrigate with water for seedling protection in time after transplanting, and make sure it is thoroughly irrigated;

[0012] S7. Maintenance: When the ground is dry and white, loosen the soil until no cracks appear, and irrigate once; in the later period, water 2-4 times a year; in the second year, remove the dead trees and replant them; in the third year, level the ridges along the slope and restore the original slope.

[0013] Moreover, in step S2, irrigation is stopped when the irrigation water surface is 10-20 cm away from the ridge top.

[0014] Moreover, in step S4, the size of the planting hole is adapted to the size of the root system of the plant variety selected in step S3.

[0015] Moreover, in step S4, the bottom of the planting hole is 5-10 cm lower than the burial depth of the original tree of the plant variety selected in step S3.

[0016] Moreover, in step S4, the diameter of the planting hole is 10-15 cm larger than the diameter of the root system of the plant variety selected in step S3.

[0017] Moreover, in step S5, the transplanted Tamarix and Weeping Willow do not have soil balls, because transplanting Tamarix and Weeping Willow with soil balls after transplanting will increase a lot of costs, and the technical solution of the present invention does not affect the survival rate of Tamarix and Weeping Willow.

[0018] Moreover, in step S5, the pruning method is: for weeping willows, the side branches are removed, and the main trunk is retained at 200-220 cm; for tamarisks, 2-3 branches are retained, and the height is retained at 20-30 cm.

[0019] It should be noted that the present invention is also applicable to transplanting Tamarix on one side of the slope and planting farmland or grass on the other side, such as Figure 4 shown.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The saline-alkali land drainage ditch plant slope consolidation method of the present invention is adopted, and weeping willows and tamarisks are selected for alternating and intermittent planting. Tamarix is ​​a salt-secreting plant with strong salt tolerance and high survival rate. It can reduce the salt content of the soil in the plant root layer and alleviate the salt persecution of the adjacent weeping willows, which is beneficial to improving the survival rate of the weeping willows. The weeping willow belongs to the tree family with a tall trunk, a large crown, and an obvious shading effect. Although its salt tolerance is weaker than that of tamarisk, its shading effect can reduce the evaporation of soil moisture, thereby reducing the surface accumulation of salt and inhibiting the return of soil salt. The two cooperate with each other to reduce the surface salt accumulation while promoting each other's growth, and the survival rate can reach more than 95%; moreover, the weeping willows and tamarisks are very resistant to cold, heat, and wind and sand, and are suitable for a wide range of planting.

[0022] 2. The present invention plants weeping willows and tamarisks on the slope of the drainage ditch and uses the plant root system to protect the slope of the drainage ditch, which has a significant slope protection effect.

[0023] 3. The present invention plants weeping willows and tamarisks on the slope of the drainage ditch. Since the planting site is on the slope of the drainage ditch and has a low terrain, the bottom water left in the channel after irrigation can be used for irrigation, thereby improving water utilization.

[0024] 4. The present invention plants trees on the slope of the drainage ditch without affecting drainage, consolidates the soil and protects the slope through underground roots, and forms a windbreak forest through above-ground branches and poles, thus providing conditions for improving the ecological environment of farmland. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the planar structure of the saline-alkali land drainage ditch plant slope fixation of the present invention;

[0026] Figure 2 For photos of ridge construction;

[0027] Figure 3 This is a diagram showing the effect of the implementation of Example 3 of the present invention;

[0028] Figure 4 This is the effect picture after transplanting Tamarix on a single-sided slope. DETAILED DESCRIPTION

[0029] Example 1

[0030] A saline-alkali land drainage ditch plant slope stabilization method comprises the following steps:

[0031] S1. Construction of ridges and ditches: In spring or autumn, dig a 45cm wide ditch 45cm above the highest water level on the slope of the drainage ditch, and build a ridge 45cm high. Build a ridge every 30m along the ridge;

[0032] S2. Irrigation and pressure salt water: Before planting, irrigate the furrows with pressure salt water;

[0033] S3. Plant variety selection: select Tamarix chinensis and Salix babylonica as the planting seedlings;

[0034] S4. Dig planting holes: When the soil in the furrow is dry and not sticky enough to the shovel, dig planting holes;

[0035] S5, transplanting: transplanting the weeping willows and tamarisks prepared in step S3 alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is 3 days;

[0036] S6. Irrigation for seedling protection: Irrigate with water for seedling protection in time after transplanting, and make sure it is thoroughly irrigated;

[0037] S7. Maintenance: When the ground is dry and white, loosen the soil until no cracks appear, and irrigate once. After that, when there is surplus water, irrigate four times a year. In the second year, remove the dead trees and replant them. In the third year, level the ridges along the slope and restore the original slope.

[0038] Furthermore, in step S2, irrigation is stopped when the irrigation water surface is 10 cm away from the ridge top.

[0039] Furthermore, in step S4, the size of the planting hole is adapted to the size of the root system of the plant variety selected in step S3.

[0040] Furthermore, in step S4, the bottom of the planting hole is 5 cm lower than the burial depth of the original tree of the plant variety selected in step S3.

[0041] Furthermore, in step S4, the diameter of the planting hole is 10 cm larger than the diameter of the root system of the plant variety selected in step S3.

[0042] Furthermore, in step S5, the transplanted Tamarix and Salix babylonica do not have soil balls.

[0043] Furthermore, in step S5, the pruning method is: for weeping willows, the side branches are removed, and the main trunk is retained at 200 cm; for tamarisks, 2 branches are retained, and the height is retained at 20 cm.

[0044] Example 2

[0045] A saline-alkali land drainage ditch plant slope stabilization method comprises the following steps:

[0046] S1. Construction of ridges and ditches: In spring or autumn, dig a 55 cm wide ditch 55 cm above the highest water level on the slope of the drainage ditch, and build a ridge every 40 m along the ridge;

[0047] S2. Irrigation and pressure salt water: Before planting, irrigate the furrows with pressure salt water;

[0048] S3. Plant variety selection: select Tamarix chinensis and Salix babylonica as the planting seedlings;

[0049] S4. Dig planting holes: When the soil in the furrow is dry and not sticky enough to the shovel, dig planting holes;

[0050] S5, transplanting: transplanting the weeping willows and tamarisks prepared in step S3 alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is 2 days;

[0051] S6. Irrigation for seedling protection: Irrigate with water for seedling protection in time after transplanting, and make sure it is thoroughly irrigated;

[0052] S7. Maintenance: When the ground is dry and white, loosen the soil until no cracks appear, and irrigate once. Later, when there is surplus water, irrigate twice a year. In the second year, remove the dead trees and replant. In the third year, level the ridges along the slope and restore the original slope.

[0053] Furthermore, in step S2, irrigation is stopped when the irrigation water surface is 20 cm away from the ridge top.

[0054] Furthermore, in step S4, the size of the planting hole is adapted to the size of the root system of the plant variety selected in step S3.

[0055] Furthermore, in step S4, the bottom of the planting hole is 10 cm lower than the burial depth of the original tree of the plant variety selected in step S3.

[0056] Furthermore, in step S4, the diameter of the planting hole is 15 cm larger than the diameter of the root system of the plant variety selected in step S3.

[0057] Furthermore, in step S5, the transplanted Tamarix and Salix babylonica do not have soil balls.

[0058] Furthermore, in step S5, the pruning method is: for weeping willows, the side branches are removed, and the main trunk is retained at 220 cm; for tamarisks, 3 branches are retained, and the height is retained at 30 cm.

[0059] Example 3

[0060] A saline-alkali land drainage ditch plant slope stabilization method comprises the following steps:

[0061] S1. Construction of ridges and ditches: In spring or autumn, dig a 50 cm wide ditch 50 cm above the highest water level on the slope of the drainage ditch, and build a ridge every 35 m along the ridge;

[0062] S2. Irrigation and pressure salt water: Before planting, irrigate the furrows with pressure salt water;

[0063] S3. Plant variety selection: select Tamarix chinensis and Salix babylonica as the planting seedlings;

[0064] S4. Dig planting holes: When the soil in the furrow is dry and not sticky enough to the shovel, dig planting holes;

[0065] S5, transplanting: transplanting the weeping willows and tamarisks prepared in step S3 alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is 1 day;

[0066] S6. Irrigation for seedling protection: Irrigate with water for seedling protection in time after transplanting, and make sure it is thoroughly irrigated;

[0067] S7. Maintenance: When the ground is dry and white, loosen the soil until no cracks appear, and irrigate once. After that, when there is surplus water, irrigate three times a year. In the second year, remove the dead trees and replant them. In the third year, level the ridges along the slope and restore the original slope.

[0068] Furthermore, in step S2, irrigation is stopped when the irrigation water surface is 15 cm away from the top of the ridge.

[0069] Furthermore, in step S4, the size of the planting hole is adapted to the size of the root system of the plant variety selected in step S3.

[0070] Furthermore, in step S4, the bottom of the planting hole is 8 cm lower than the burial depth of the original tree of the plant variety selected in step S3.

[0071] Furthermore, in step S4, the diameter of the planting hole is 12 cm larger than the diameter of the root system of the plant variety selected in step S3.

[0072] Furthermore, in step S5, the transplanted Tamarix and Salix babylonica do not have soil balls.

[0073] Furthermore, in step S5, the pruning method is: for weeping willows, the side branches are removed, and the main trunk is retained at 210 cm; for tamarisks, 3 branches are retained, and the height is retained at 25 cm.

[0074] Comparative Example 1

[0075] This comparative example is the same as Example 3 except that the plant species selected and transplanted are all Tamarix chinensis.

[0076] Comparative Example 2

[0077] This comparative example is the same as Example 3 except that the plant species selected and transplanted are all weeping willows.

[0078] Comparative Example 3

[0079] This comparative example is the same as Example 3 except that in step S1, when constructing the ditch, the ditch is dug on the slope of the drainage ditch, 40 cm above the highest water level.

[0080] Comparative Example 4

[0081] This comparative example is the same as Example 3 except that in step S1, when constructing the ditch, the ditch is dug on the slope of the drainage ditch, 60 cm above the highest water level.

[0082] Experimental Section

[0083] Experiment 1

[0084] One year later, the survival rates of the seedlings of Examples 1-3 and Comparative Examples 1-4 were statistically analyzed and the slope fixation conditions were observed and recorded, as shown in Table 1.

[0085] Table 1 Seedling survival rate and slope retention

[0086]

[0087] As can be seen from Table 1, by adopting the technical scheme of the present invention, the survival rate of seedlings can reach up to 96.1%, the slope is intact and the fixing effect is also good; in comparison example 1, all Tamarix spp. are planted, in comparison example 2, all Weeping Willows are planted, in comparison example 3, Weeping Willows and Tamarix spp. are planted at a relatively low distance from the drainage ditch, and in comparison example 4, Weeping Willows and Tamarix spp. are planted at a relatively high and remote distance from the drainage ditch. The survival rates of seedlings are 70.1%, 72.3%, 80.2% and 79.5% respectively, and some areas of the slope collapse. The effect is significantly different from that of the present invention, which can prove that the technical scheme of the present invention is the best scheme.

[0088] Experiment 2

[0089] One year later, the slopes of Examples 1-3 and Comparative Examples 1-4 were subjected to an anti-scouring test: the slopes of Examples 1-3 and Comparative Examples 1-4 were scoured for 20 minutes in a simulated moderate rain scouring process, and a slope area of ​​length x width x height = 2m x 1m x 0.5m was selected to calculate the soil loss. The results are shown in Table 2.

[0090] Table 2 Slope scour resistance

[0091]

[0092] It can be seen from Table 2 that the technical solution of the present invention has a better retaining effect on the slope and improves the ability to resist rain erosion.

[0093] Experiment 3

[0094] Take the soil 10-20 cm below the slope of Examples 1-3 and Comparative Examples 1-4, remove large particles of impurities, weigh 100 g of each and put it into a small beaker, add 250 mL of distilled water, stir to fully disperse the soil particles, let it stand for half an hour to fully dissolve the soluble salt, filter, collect the filtrate and evaporate it to dryness, dry it, and weigh the mass of the drying residue, that is, the mass of salt in the soil, as shown in Table 3.

[0095] Table 3 Water-soluble salt content of slope soil

[0096]

[0097] It can be seen from Table 3 that the soil salt content of the slope treated by the technical solution of the present invention is lower than that of other groups, which can prove that the technical solution of the present invention can prevent land salinization.

[0098] Experiment 4

[0099] The soil layer at 40 cm of the slope of Examples 1-3 and Comparative Examples 1-4 was taken to test its shear resistance, as shown in Table 4.

[0100] Table 4 Slope shear capacity

[0101]

[0102] It can be seen from Table 3 that the adoption of the technical solution of the present invention can improve the shear stress of the slope surface, improve the stability of the slope, and achieve a better slope consolidation effect.

Claims

1. A method for stabilizing the slope of a saline-alkali drainage ditch by plants, characterized in that: The steps include: S1. Construction of ridges: In spring or autumn, dig a 45-55cm wide ridge 45-55cm high on the slope of the drainage ditch 45-55cm above the highest water level, and build a ridge every 30-40m along the ridge; S2. Irrigation with pressurized salt water: Before planting, irrigate the ridge furrow with pressurized salt water; stop irrigation when the irrigated water surface is 10-20cm from the top of the ridge; S3. Plant variety selection: select Tamarix chinensis and Salix babylonica as the planting seedlings; S4, digging planting holes: when the soil in the furrow is dry and not easily sticky to the shovel, dig the planting holes; the bottom of the planting holes is 5-10 cm lower than the burial depth of the original tree of the plant variety selected in step S3; the diameter of the planting holes is 10-15 cm larger than the diameter of the root system of the plant variety selected in step S3; S5, transplanting: transplanting the weeping willows and tamarisks prepared in step S3 alternately and at intervals into the planting holes dug in step S4; the time interval from seedling removal to planting of tamarisks and weeping willows is ≤ 3 days; S6. Irrigation for seedling protection: Irrigate with water for seedling protection in time after transplanting, and make sure it is thoroughly irrigated; S7. Maintenance: When the ground is dry and white, loosen the soil until no cracks appear, and irrigate once; in the later period, water 2-4 times a year; in the second year, remove the dead trees and replant them; in the third year, level the ridges along the slope and restore the original slope.

2. A saline-alkali land drainage ditch plant slope stabilization method as claimed in claim 1, characterized in that: In step S4, the size of the planting hole is adapted to the size of the root system of the plant variety selected in step S3.

3. The method for slope stabilization by plants in drainage ditches in saline-alkali land according to claim 1, characterized in that: In step S5, the transplanted Tamarix and Salix babylonica do not have soil balls.

4. A saline-alkali land drainage ditch plant slope stabilization method as claimed in claim 1, characterized in that: In step S5, the pruning method is: for weeping willows, the side branches are removed, and the main trunk is retained at 200-220 cm; for tamarisks, 2-3 branches are retained, and the height is retained at 20-30 cm.

Images