Method for inducing infiltration of root systems of sandy vegetation

Abstract

The invention discloses a method for inducing infiltration of root systems of sandy vegetation. The method comprises the steps of land selection and preparation, pit digging, vegetation selection, arrangement of a PVC pipe water applying system, vegetation planting and backfilling and layered water control operation. According to the method, PVC pipes with water seepage holes with different depths are arranged near the root system of vegetation, a self-descending and lifting piston structure of a water-absorbing expansion cylindrical block and a depth-keeping hook-hanging ring chain is adopted in the pipes for the first time, and the distance between the water seepage holes, the length of a rope section and the size of a hanging ring are accurately calculated, so that it is guaranteed that the distance between the water seepage holes and the rope section is accurately calculated at each stage; water can only seep from the water seepage holes with the specific target depth, the root system is guided to follow a water signal to be deeply pricked downwards continuously, a deep and developed root system is formed, accurate layered water control and root system directional induction are achieved, the drought resistance and wind falling resistance of vegetation are greatly enhanced, the water consumption is low, the vegetation survival rate is high, and the growth vigor is good; the depth-keeping water applying system serves as a multifunctional and permanent ecological restoration unit and further has the functions of soil ventilation, humidification and self-cleaning.

Description

Technical Field

[0001] This invention relates to the field of desert ecological restoration technology, and in particular to a method for inducing root infiltration in desert vegetation. Background Technology

[0002] Desertification is a major global ecological problem, and the key to combating desertification lies in restoring and rebuilding stable desert vegetation systems. However, in arid and semi-arid desert environments, water resources are extremely scarce and evaporation is intense. Desert areas have little rainfall and high evaporation rates, which pose challenges to vegetation planting, such as shallow root systems and low survival rates. The core challenge is how to efficiently utilize limited water resources and ensure the survival and stable growth of vegetation.

[0003] Traditional desert vegetation irrigation methods, such as flood irrigation and drip irrigation, have significant drawbacks: water is mainly concentrated in the surface or shallow soil and is easily lost through surface evaporation, resulting in extremely low water use efficiency. This causes vegetation roots to tend to grow horizontally in the topsoil to obtain water, forming a "shallow-root" root structure. Such roots cannot effectively anchor themselves in the soil, resulting in poor wind erosion resistance and easy lodging and death of the vegetation. At the same time, shallow roots cannot utilize the relatively stable water that may exist in the deeper soil, making the vegetation extremely vulnerable during drought periods, with low survival rates and stability.

[0004] To address these issues, existing technologies have explored several deep irrigation or root control methods. For example, deep pipes are buried near plants to directly inject water into deeper soil layers, inducing root growth. However, these methods often lack precise, layered water control, either injecting water to the deepest point all at once without inducing root growth in stages. Another common method is to gradually increase the depth of the irrigation holes, but this method results in rapid water infiltration, difficulty in controlling the distribution area, and requires repeated drilling, making it cumbersome, causing significant soil disturbance, and resulting in substantial water loss through evaporation and deep seepage. This also fails to achieve precise, water-saving root induction. Other methods utilize water-retaining agents to improve water supply, but these lack active guidance on root growth direction, failing to effectively promote root extension into deeper soil layers and impacting the long-term survival of the vegetation.

[0005] Therefore, there is an urgent need in this field for a method for root infiltration in psammophyte vegetation that can precisely control the depth and speed of water infiltration, actively induce root growth in stages, and significantly improve water use efficiency. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for inducing root infiltration in psammophytic vegetation.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for inducing root infiltration in psammophytic vegetation includes the following steps:

[0009] a. Site selection and land preparation

[0010] Select a relatively flat area in the desert, remove stones, dead branches and other debris with a diameter greater than 5cm from the ground, level the land and ensure that the slope is ≤5° to facilitate the vertical burial of PVC pipes and the uniform infiltration of water.

[0011] b. Digging a hole

[0012] Dig planting pits with a plant spacing of 2-3m and a row spacing of 3-4m. The diameter of the planting pit should be 50-60cm and the depth should be 40-50cm. The bottom of the pit should be leveled to ensure that the plant roots can spread out.

[0013] c. Vegetation selection

[0014] Select drought- and salt-tolerant native sandy vegetation, such as Haloxylon ammodendron, Tamarix chinensis, and Hippophae rhamnoides, requiring robust plants with prominent taproots and root lengths ≥30cm;

[0015] d. PVC pipe water supply system setup

[0016] ① Pipe material selection:

[0017] Select a PVC pipe with a diameter of 20-25cm and a length of 2.1m. The pipe wall is evenly opened with seepage holes with a diameter of 5-8mm. Multiple seepage holes are distributed in a spiral shape along the pipe wall. The vertical distance between the center of the top seepage hole and the top of the PVC pipe is 30cm, and the vertical distance between the centers of adjacent seepage holes is 30cm.

[0018] ② Fixed-depth conversion:

[0019] A support rod is fixedly installed on the inner wall of the top opening of the PVC pipe. A fixed depth hook is fixedly installed on the bottom surface of the support rod. A spring tongue is in contact with the curved end of the fixed depth hook. The end of the spring tongue away from the curved end is fixedly connected to the vertical section of the fixed depth hook.

[0020] The fixed-depth hook is connected to a fixed-depth rope, which is composed of 6 rope segments of equal length connected in series by 6 hanging rings. One end of the rope segment at the bottom of the fixed-depth rope is connected to a water-absorbing and expanding cylindrical block. The depth of the water-absorbing and expanding cylindrical block is controlled by connecting different hanging rings to the fixed-depth hook.

[0021] ③ Installation method:

[0022] The pre-assembled PVC pipe is vertically buried 20-30cm away from the planting pit, with the pipe opening 5-10cm above the ground. The bottom of the pipe does not need to be sealed, and the pipe body should be kept at an appropriate distance from the plant roots to avoid damaging the roots.

[0023] e. Vegetation planting and backfilling

[0024] Place the selected plants upright in the planting pit, spread out their roots, then backfill with soil and gently compact it in layers to ensure that the roots are in close contact with the soil.

[0025] After backfilling, water thoroughly to settle the roots. The amount of water should be about 1 / 2 to 2 / 3 of the pit volume, so that the soil moisture content around the roots reaches 15% to 20%.

[0026] f. Layered water control operation

[0027] Initial stage: Water is supplied to the shallow soil layer with a depth of 15-20cm through the seepage hole at the very top of the PVC pipe;

[0028] Intermediate stage: Water is supplied to the soil to a depth of 45-50cm through the second highest seepage hole in the PVC pipe;

[0029] Later stage: Every 1-2 months, water is supplied to the soil at depths of 75-80cm, 105-110cm, 135-140cm, and 165-170cm respectively through the third, fourth, fifth, and sixth drainage holes of the PVC pipe.

[0030] Preferably, the rope segment length is 28cm and the inner diameter of the hanging ring is 2.5cm, so that when each rope segment is lowered, the water-absorbing and expanding cylindrical block is slightly lower than the seepage hole, ensuring that water is directly delivered to the soil at the corresponding depth through the seepage hole after irrigation;

[0031] The diameter of the water-absorbing and expanding cylindrical block is slightly smaller than the inner diameter of the PVC pipe in the dry state, which makes it easy to lower and lift. After absorbing water, the water-absorbing and expanding cylindrical block can expand rapidly and form a tight sealing piston structure with the inner wall of the PVC pipe.

[0032] Preferably, the water-absorbing and expanding cylindrical block is prepared by the following steps:

[0033] Take a cylindrical stone with a diameter of PVC pipe inner diameter R-2cm and a height of 10cm, and apply a ring of water-absorbing and expanding sealing strip to the curved surface of the cylindrical stone.

[0034] The dry thickness of the water-absorbing and expanding sealing strip is 1cm, and the thickness after absorbing water and expanding is 2.3-2.8cm, thus ensuring that the wet water-absorbing and expanding cylindrical block can be tightly attached to the inner wall of the PVC pipe to form a relatively sealed structure; the water-absorbing and expanding sealing strip (water-swellable sealing strip, Hengshui Ousheng Engineering Rubber Co., Ltd.) is bonded to the side of the cylindrical stone with melamine glue.

[0035] Preferably, f. the stratified water control operation specifically includes the following steps:

[0036] Initial stage (3-5 months after planting): Inject 5-10L of water into the PVC pipe through the pipe opening. Attach all the loops of the depth-fixing rope to the depth-fixing hook and lock them with a spring tongue to prevent them from falling off. The water-absorbing and expanding cylindrical block quickly absorbs water and forms a relatively sealed structure with the inner wall of the PVC pipe. Under the action of gravity, it sinks to a depth of 32cm (distance from the pipe opening). The topmost seepage hole then leaks out through a hole with a radius of R+2cm. The water seeps into the shallow soil layer to a depth of 15-20cm (depth from the ground), and the seepage speed is relatively slow, promoting the lateral development of the roots and increasing the root diameter.

[0037] Mid-term stage (5-6 months after planting): Repeat the watering operation, unload the first hanging ring, and let the water-absorbing and expanding cylindrical block sink to a depth of 62.5cm. Then, let the second highest seepage hole expose the hole part with a radius of R+2.5cm, and the seepage speed will be slightly accelerated. The water seeps into the soil to a depth of 45-50cm, which will promote the root system to develop along the depth and further penetrate, that is, increase the root system length.

[0038] Later stage: Subsequently, every 1-2 months (which can be shortened to 20-30 days during dry periods), the second, third, fourth, and fifth hanging rings are unloaded and attached to the fixed-depth hooks in sequence. Each water injection can achieve precise fixed-depth water supply to the soil at depths of 75-80cm, 105-110cm, 135-140cm, and 165-170cm. The water leakage from each seepage hole is successively reduced to holes with radii of R+3cm, R+3.5cm, R+4cm, and R+4.5cm, with the seepage rate gradient increasing. During non-drought periods, the water supply frequency gradually increases from 3 days / time to 2.7 days / time, 2.3 days / time, and 1.8 days / time. During drought periods, the water supply frequency doubles. The interval between each operation is adjusted according to soil moisture and vegetation growth. By increasing the water supply depth in stages, the vegetation roots are continuously guided to follow the water to grow into deeper soil layers.

[0039] The water-absorbing and expanding cylindrical blocks allow water to seep into the bottom of the PVC pipe through the soil at a depth of 195-200cm. The water at the bottom of the pipe mainly comes from natural capillary seepage during each watering interval and from water leakage through the gaps in the early stages of each watering when the water-absorbing and expanding cylindrical blocks have not yet expanded. This keeps the soil at a depth of 195-200cm moist for a long time, which can further improve desert soil and climate and always ensure the driving force for the roots to grow downward. In particular, during each watering interval, the water-absorbing and expanding cylindrical blocks automatically release water to replenish the deep soil along the PVC pipe wall.

[0040] In some embodiments of this invention, when vegetation lodging or severe drought occurs, the vegetation is straightened and fixed with supports; the five hanging rings on the depth-fixing hook are unloaded, so that the water-absorbing and expanding cylindrical block is at its deepest point; water is continuously added at a flow rate of 1L / min; within 1 minute, the depth-fixing rope is slowly stretched to bring the water-absorbing and expanding cylindrical block to its highest position, creating a vacuum in the PVC pipe, absorbing gas from the soil, and then allowing it to naturally descend, allowing water to gradually penetrate into the soil at various depths. Due to the previous soil vacuum state, the water quickly fills the soil area; the above operation is continued until the soil moisture content near the PVC pipe reaches 20-25%, then water addition is stopped, thereby achieving emergency soil depth-fixed irrigation, while also making the desert soil more compact, preventing lodging, and achieving permanent straightening.

[0041] In some embodiments of the present invention, during desert nights, a funnel-shaped film can be placed above the PVC pipe using a support, and the bottom of the funnel-shaped film has a through hole, so that moisture in the desert air condenses on the surface of the film and flows into the PVC pipe, thereby achieving nighttime water replenishment and ensuring the humid state of the PVC pipe and the water-absorbing and expanding cylindrical block inside.

[0042] In some embodiments of the present invention, a layer of straw can be covered on top of the PVC pipe, and the two ends of the straw are fixed by covering with soil to prevent the risk of wind and sand settling and blocking the pipe and holes. The straw can be lifted up when in use.

[0043] In some embodiments of the present invention, when sand adheres to the inner wall of the PVC pipe, 5-8L of water can be added, the five hanging rings on the fixed depth hook can be unloaded, so that the water-absorbing expansion cylinder is at the deepest point, and then the fixed depth rope can be quickly stretched to make the water-absorbing expansion cylinder the highest position. A vacuum cleaner can be used to absorb the sand on the upper surface of the water-absorbing expansion cylinder, thereby ensuring that the inner wall of the PVC pipe is clean and avoiding clogging of the various seepage holes.

[0044] In some implementations of this invention, when the moisture content of the deep soil at the bottom of the PVC pipe is high (≥15%), 2-3L of water can be added to make the water-absorbing and expanding cylindrical block absorb water and expand. The five hanging rings on the fixed-depth hook are unloaded, so that the water-absorbing and expanding cylindrical block is located at the deepest point. Then, the fixed-depth rope is stretched and released back and forth, and the underground moisture is drawn into the PVC pipe using vacuum. Then, it is released into the soil at different depths through each seepage hole in sequence, so as to realize the change of soil gas humidity.

[0045] The permanent watering system formed by PVC pipes can serve as a channel for soil gas exchange. Especially at night, it can introduce high-humidity air above the soil into the soil at various depths through the seepage holes, reducing the amount of water applied. During periods of infrequent rainfall, multiple PVC pipes can also act as a water storage network, further extending the soil moisture time caused by rainfall, thereby changing the soil and the surrounding climate.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] 1. This invention involves arranging PVC pipes with seepage holes near the roots of vegetation, and for the first time employing a self-lowering and lifting piston structure with a water-absorbing and expanding cylindrical block and a fixed-depth hook-ring chain inside the pipe. The dry water-absorbing and expanding cylindrical block is easily lowered to a predetermined depth. After swelling upon contact with water, it forms a relatively sealed piston structure with the inner wall of the PVC pipe. The piston sinks under gravity, sealing the water in its upper part. By selecting different hanging rings and hooks for connection, the initial dwell depth of the piston can be precisely controlled. When the piston sinks to the first unblocked seepage hole in its upper part, the water can only seep out from that hole and the holes above it.

[0048] 2. The present invention also ensures that water can only seep out from the seepage holes at a specific target depth at each stage by accurately calculating the spacing between the seepage holes, the length of the rope segment and the size of the hanging ring (such as seeping out from the hole 30cm from the top of the pipe in the early stage, corresponding to the shallow soil), thus achieving a step-by-step precise control of the water supply depth from shallow to deep.

[0049] 3. This invention utilizes the principle that plant roots are naturally "hydrotropic" and will actively grow towards areas with concentrated moisture. By changing the position of the moisture peak in the soil in stages and precisely, the root system is actively and forcibly guided to follow the moisture signal and grow deeper, thereby forming a deep and developed root system. This achieves precise stratified water control and directional root induction, greatly enhancing the drought resistance and windbreak resistance of the vegetation.

[0050] 4. The relatively sealed piston structure of this invention has a high water-saving effect. To achieve the same soil moisture effect around the roots, traditional methods require several times the amount of water or a higher irrigation frequency. This greatly reduces the amount of water used per irrigation and the total number of irrigations, achieving precise water-saving irrigation.

[0051] ① Sealed piston reduces ineffective leakage: The sealing structure formed by the water-absorbing expansion block effectively prevents premature leakage of water into non-target deep soil layers, ensuring that almost all water seeps out slowly from the seepage pores in the current target layer. ② Slow seepage promotes lateral diffusion: Water seeps out from the limited seepage pores at a relatively slow rate, which facilitates the full diffusion of water in the horizontal direction of the soil, forming a wider and flatter moist body, rather than rapidly flowing directly to the deep layers. This allows more roots to come into contact with water, reducing deep seepage losses. ③ Direct action on the root zone: Water is directly transported to the target soil layer through pipes, completely avoiding surface evaporation losses caused by surface irrigation.

[0052] On the other hand, it also significantly improves the survival rate and growth vigor of vegetation. Through phased induction, the vegetation can eventually form a huge root network up to 2 meters deep. The deep soil moisture conditions are relatively stable and less affected by surface climate change. Vegetation with deep roots can utilize the stable moisture in the deep soil, thus better resisting extreme drought weather on the surface and reducing environmental stress. Moreover, the continuous supply of deep water provides the vegetation with a "life source of water", significantly improving the survival rate under extreme drought conditions and reducing the cost and workload of later replanting.

[0053] 5. The fixed-depth water supply system of the present invention can change the water supply depth through a simple "replacement" operation, and also has a variety of practical functions: such as vacuum-assisted emergency irrigation: quickly improve soil compaction and moisture content; nighttime condensation water replenishment: develop unconventional water sources; anti-clogging and self-cleaning: ensure the long-term effectiveness of the system; soil gas exchange: improve the rhizosphere environment; making the PVC pipe system a multifunctional and permanent ecological restoration unit.

[0054] 6. Using the fixed-depth watering method of the present invention to induce root growth, deep-rooted vegetation can be obtained. Its soil-fixing and anchoring ability is much stronger than that of shallow-rooted vegetation. It can more effectively fix shifting sand and stabilize sand dunes. Moreover, after the vegetation is established, the strong deep root system can be self-sustaining, which greatly enhances the stability and resilience of the ecosystem, effectively reduces wind and sand damage, accelerates the process of desert ecological restoration, and brings long-term ecological and social benefits.

[0055] 7. In summary, this invention, through an ingenious pipeline modification design, applies simple physical principles (gravity, sealing, siphon / vacuum) to ecological governance, achieving proactive induction of root growth in desert vegetation, and making breakthrough progress in water conservation, efficiency enhancement, improved survival rate, and promotion of ecological stability. Attached Figure Description

[0056] Figure 1 This is a field layout diagram (including precise size settings) of a method for inducing root infiltration in psammophytic vegetation proposed in this invention.

[0057] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0058] Figure 3 This is an internal structural diagram of the PVC pipe watering system used in a method for inducing root infiltration of sand-loving vegetation proposed in this invention.

[0059] Figure 4 for Figure 3 A magnified view of a portion of the image, B.

[0060] In the diagram: planting pit 1, PVC pipe 2, drainage hole 201, support rod 301, fixed depth hook 302, spring tongue 303, rope segment 401, hanging ring 402, water-absorbing and expanding cylindrical block 5;

[0061] Figure 1 The unit for dimensioning is cm. Detailed Implementation

[0062] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0063] Example 1:

[0064] A method for inducing root infiltration in psammophytic vegetation includes the following steps:

[0065] a. Site selection and land preparation

[0066] Select a relatively flat area in the desert, remove stones, dead branches and other debris with a diameter greater than 5cm from the ground, level the land and ensure that the slope is ≤5° to facilitate the vertical burial of PVC pipes and the uniform infiltration of water.

[0067] b. Digging a hole

[0068] Dig planting pit 1 with a plant spacing of 2-3m and a row spacing of 3-4m. The diameter of planting pit 1 is 50-60cm and the depth is 40-50cm. The bottom of the pit should be leveled to ensure that the plant roots can spread out.

[0069] c. Vegetation selection

[0070] Select drought- and salt-tolerant native sandy vegetation, such as Haloxylon ammodendron, Tamarix chinensis, and Hippophae rhamnoides, requiring robust plants with prominent taproots and root lengths ≥30cm;

[0071] d. PVC pipe water supply system setup

[0072] ① Pipe material selection:

[0073] Select a PVC pipe 2 with a diameter of 20-25cm and a length of 2.1m. The pipe wall is evenly opened with seepage holes 201 with a diameter of 5-8mm. Multiple seepage holes 201 are distributed in a spiral shape along the pipe wall. The vertical distance between the center of the top seepage hole 201 and the top of the PVC pipe 2 is 30cm, and the vertical distance between the centers of adjacent seepage holes 201 is 30cm.

[0074] ② Fixed-depth conversion:

[0075] A support rod 301 is fixedly installed on the inner wall of the top opening of the PVC pipe 2. A fixed depth hook 302 is fixedly installed on the bottom surface of the support rod 301. A spring tongue 303 is in contact with the curved end of the fixed depth hook 302. The end of the spring tongue 303 away from the curved end is fixedly connected to the vertical section of the fixed depth hook 302.

[0076] The fixed depth hook 302 is connected to a fixed depth rope, which is composed of 6 rope segments 401 of equal length connected in series by 6 hanging rings 402. One end of the rope segment 401 at the bottom of the fixed depth rope is connected to a water-absorbing and expanding cylindrical block 5. The depth of the water-absorbing and expanding cylindrical block 5 is controlled by connecting different hanging rings 402 to the fixed depth hook 302.

[0077] The rope segment 401 is 28cm long and the inner diameter of the hanging ring 402 is 2.5cm. When each rope segment 401 is lowered, the water-absorbing and expanding cylindrical block 5 is slightly lower than the seepage hole 201, ensuring that water is directly delivered to the soil at the corresponding depth through the seepage hole 201 after irrigation.

[0078] The diameter of the water-absorbing and expanding cylindrical block 5 is slightly smaller than the inner diameter of the PVC pipe 2 in the dry state, which makes it easy to lower and lift. After absorbing water, the water-absorbing and expanding cylindrical block 5 can expand rapidly and form a tight sealed piston structure with the inner wall of the PVC pipe.

[0079] ③ Installation method:

[0080] like Figure 1 As shown, the pre-assembled PVC pipe 2 is vertically buried 120-30cm away from the planting pit, with the pipe opening 5-10cm above the ground. The bottom of the pipe does not need to be sealed, and the pipe body should be kept at an appropriate distance from the plant roots to avoid damaging the roots.

[0081] e. Vegetation planting and backfilling

[0082] Place the selected plants upright in planting pit 1, spread out their roots, then backfill with soil and gently compact it in layers to ensure that the roots are in close contact with the soil.

[0083] After backfilling, water thoroughly to settle the roots. The amount of water should be about 1 / 2 to 2 / 3 of the pit volume, so that the soil moisture content around the roots reaches 15% to 20%.

[0084] f. Layered water control operation

[0085] Initial stage (3-5 months after planting): such as Figure 3 and Figure 4As shown, 5-10L of water is injected into the PVC pipe 2 through the pipe opening. All the hanging rings 402 of the fixed depth rope are hung on the fixed depth hook 302 and locked by the spring tongue 303 to prevent them from falling off. The water-absorbing and expanding cylindrical block 5 quickly absorbs water and forms a relatively sealed structure with the inner wall of the PVC pipe 2. Under the action of gravity, it sinks to a depth of 32cm (distance from the pipe opening). The topmost seepage hole 201 leaks out of the hole with a radius of R+2cm. The water seeps into the shallow soil layer with a depth of 15-20cm (depth from the ground), and the seepage speed is relatively slow, which promotes the lateral development of the root system and increases the root diameter.

[0086] Mid-term stage (5-6 months after planting): Repeat the watering operation, unload the first hanging ring 402, and let the water-absorbing and expanding cylindrical block 5 sink to a depth of 62.5cm. Then, let the second highest seepage hole 201 expose the hole part with a radius of R+2.5cm, and the seepage speed will be slightly accelerated. The water seeps into the soil to a depth of 45-50cm, which will promote the root system to develop along the depth and further penetrate, that is, increase the root system length.

[0087] Later stage: Subsequently, every 1-2 months (which can be shortened to 20-30 days during dry periods), the second, third, fourth, and fifth hanging rings 402 are unloaded and attached to the fixed-depth hooks 302. Each water injection can achieve precise fixed-depth water supply to the soil at depths of 75-80cm, 105-110cm, 135-140cm, and 165-170cm. The water infiltration holes 201 successively leak out holes with radii of R+3cm, R+3.5cm, R+4cm, and R+4.5cm, with the infiltration rate gradient increasing. During non-drought periods, the water supply frequency gradually increases from 3 days / time to 2.7 days / time, 2.3 days / time, and 1.8 days / time. During drought periods, the water supply frequency doubles. The interval between each operation is adjusted according to soil moisture and vegetation growth. By increasing the water supply depth in stages, the vegetation roots are continuously guided to follow the water to grow into deeper soil layers.

[0088] Meanwhile, the water-absorbing and expanding cylindrical block 5 permeates the soil at a depth of 195-200cm to the bottom of the PVC pipe 2 (the water at the bottom of the pipe mainly comes from natural capillary seepage during each watering interval and from water leakage through the gaps in the early stages of each watering when the water-absorbing and expanding cylindrical block has not yet expanded), maintaining a long-term moist state for the soil at a depth of 195-200cm underground. This can further improve the desert soil and climate, and always ensure the driving force for the roots to grow downwards. In particular, during each watering interval, the water-absorbing and expanding cylindrical block 5 automatically releases water to replenish the deep soil along the pipe wall of the PVC pipe 2.

[0089] The water-absorbing and expanding cylindrical block 5 is prepared through the following steps:

[0090] Take a cylindrical stone (made of stones and cement bonded together and dried in a 1:1 weight ratio) with an inner diameter of PVC pipe 2 (R-2cm) and a height of 10cm. Apply a ring of water-absorbing and expanding sealing strip to the curved surface of the cylindrical stone.

[0091] The dry thickness of the water-absorbing and expanding sealing strip is 1cm, and the thickness after absorbing water and expanding is 2.3-2.8cm, thus ensuring that the wet water-absorbing and expanding cylindrical block 5 can be tightly attached to the inner wall of the PVC pipe 2 to form a relatively sealed structure; the water-absorbing and expanding sealing strip (water-swellable water-stop strip, Hengshui Ousheng Engineering Rubber Co., Ltd.) is bonded to the side of the cylindrical block with melamine glue.

[0092] Comparative Example 1

[0093] The PVC pipe arrangement differs from that in Example 1:

[0094] 1. Pipe specifications: PVC pipes with a diameter of 20-25cm and a length of 2.1m are selected. Drainage holes with a diameter of 5-8mm are evenly opened on the pipe wall, with a hole spacing of 10-15cm and a spiral distribution.

[0095] 2. Plug Installation: Cut the foam plastic into cylindrical plugs that fit the inner diameter of the PVC pipe. Install one plug every 30cm of pipe length, and connect them together with nylon rope (1-2mm in diameter) to form a plug chain. Fix the end of the rope to the outside of the pipe opening. The plugs must tightly seal the pipe opening to prevent premature water leakage.

[0096] 3. Installation method: Vertically bury the PVC pipe 20-30cm away from the planting pit, with the pipe opening 5-10cm above the ground. The bottom of the pipe does not need to be sealed. Maintain an appropriate distance between the pipe and the plant roots to avoid damaging them.

[0097] This also results in f. the stratified water control operation differing from Example 1:

[0098] 1. Initial stage (3-5 months after planting): Inject water into the pipe through the PVC pipe opening, 5-10L per injection. Slowly pull up the first plug (30cm from the pipe opening), leaving the other plugs in place. Water will seep out from the pores in this layer, penetrating to a depth of 30cm, inducing the roots to extend into the shallow soil.

[0099] 2. Mid-term stage (5-6 months after planting): After repeating the watering operation, pull up the second plug (60cm from the pipe opening). At this time, the water seeps down to a depth of 60cm, which encourages the roots to penetrate further.

[0100] 3. Later stage: Every 1-2 months, pull up the remaining plugs one by one, increasing the infiltration depth by 30cm each time, until all plugs are removed (total depth 2.1m). The interval between each operation is adjusted according to soil moisture and vegetation growth, and can be shortened to 20-30 days during dry periods.

[0101] The remaining operations are the same as in Example 1. Comparative Example 1 is an experiment previously conducted by this invention. Because it was impossible to control the direction of the water, most of the water actually entered the soil about 2m underground along the PVC pipe. The effect of inducing root growth in the early and middle stages was not obvious. Therefore, this invention proposed the scheme of Example 1 for optimization. After optimization, the root volume in the early stage of Example 1 is 1.5-1.8 times that of the root volume in the early stage of Comparative Example 1 (taking Haloxylon ammodendron as an example, and multiple PVC pipes 2 are evenly arranged in a ring around the planting pit).

[0102] Comparative Example 2

[0103] Using the commonly used method of drilling holes while watering, the drilling depth varies at different times, resulting in excessively rapid water penetration. To maintain the same level of moisture in the holes as in Example 1, the conditions are: a single watering volume of 3-5 times that of Example 1 or a watering frequency of 2-3 times that of Example 1. Even with the same level of moisture in the holes as in Example 1, the root volume in the early stage of vegetation is 81% of that in Example 1, and the root volume in the middle and late stages is 52% and 65% of that in Example 1, respectively. This is sufficient to demonstrate that the present invention has a water-saving effect and also has a significant root-inducing growth function.

[0104] Example 2

[0105] Based on Example 1, when vegetation lodging or severe drought occurs, the vegetation is straightened and fixed with supports; the five hanging rings 402 on the depth-fixing hook 302 are unloaded, so that the water-absorbing and expanding cylindrical block 5 is at the deepest point. Water is continuously added at a flow rate of 1L / min. Within 1 minute, the depth-fixing rope is slowly stretched to bring the water-absorbing and expanding cylindrical block 5 to the highest position, creating a vacuum in the PVC pipe 2, absorbing gas from the soil, and then naturally lowered, allowing water to gradually penetrate into the soil at various depths. Due to the previous soil vacuum state, water quickly fills the soil. The above operation is continued until the soil moisture content near the PVC pipe 2 reaches 20-25%, then water addition is stopped, thereby achieving emergency soil depth-fixed irrigation. At the same time, it makes the desert soil more compact, avoids lodging, and achieves permanent straightening. Under 6-7 level sandstorm conditions, the vegetation lodging rate is reduced by 85% after the supports are unloaded.

[0106] Example 3

[0107] Based on Example 1, during desert nights, a funnel-shaped film can be installed above the PVC pipe 2 using a support frame. The bottom of the funnel-shaped film has through holes, allowing moisture in the desert air to condense on the film surface and flow into the PVC pipe 2, thus replenishing water at night and ensuring the PVC pipe 2 and its internal water-absorbing and expanding cylindrical block 5 remain moist. During the experiment at the Mu Us Desert base, when the single water application volume in Example 3 was approximately 4.5% less than that in Example 1, the PVC pipe 2 and its internal water-absorbing and expanding cylindrical block 5 remained moist for the same amount of time. Although the water reduction effect was not significant, it can be predicted that this air-based water extraction method could become a desert water extraction method. In the future, more advanced air-based water extraction methods can be used to achieve short-term soil self-sufficiency.

[0108] Example 4

[0109] Based on Example 1, a layer of straw can be placed on top of the PVC pipe 2. The two ends of the straw are fixed by covering with soil to prevent the risk of wind and sand settling and blocking the pipe and holes. The straw can be lifted up when in use.

[0110] Example 5

[0111] Based on Example 1, when sand adheres to the inner wall of PVC pipe 2, 5-8L of water can be added, and the five hanging rings 402 on the fixed depth hook 302 can be unloaded so that the water-absorbing expansion cylinder 5 is at the deepest point. Then, the fixed depth rope is quickly stretched so that the water-absorbing expansion cylinder 5 is at the highest position. A vacuum cleaner is used to absorb the sand on the upper surface of the water-absorbing expansion cylinder 5, thereby ensuring that the inner wall of PVC pipe 2 is clean and avoiding clogging of the various seepage holes 201.

[0112] Example 6

[0113] Based on Example 1, when the moisture content of the deep soil at the bottom of the PVC pipe 2 is high (≥15%), 2-3L of water can be added to make the water-absorbing and expanding cylindrical block 5 absorb water and expand. The five hanging rings 402 on the fixed-depth hook 302 are unloaded so that the water-absorbing and expanding cylindrical block 5 is located at the deepest point. Then, the fixed-depth rope is stretched and released back and forth to draw underground moisture into the PVC pipe 2 using vacuum. Then, it is released into the soil at different depths through each seepage hole 201 in sequence to achieve the change of soil gas humidity.

[0114] The permanent watering system formed by PVC pipe 2 can serve as a channel for soil gas exchange. Especially at night, it can introduce high-humidity air above the soil into the soil at various depths through the infiltration holes 201, reducing the amount of water applied. During periods of infrequent rainfall, multiple PVC pipes 2 can also serve as a water storage network, further extending the soil moisture time caused by rainfall, thereby changing the soil and the surrounding climate.

[0115] Based on the experimental results of the above embodiments, the present invention can preliminarily draw the following conclusions:

[0116] 1) Precise Depth Water Supply: An innovative combination of a "water-absorbing expansion block piston" and a "depth-fixed hook-ring system" replaces the cumbersome manual operation of pulling up the plug. By simply changing the mounting point, precise water supply to different depths can be achieved. Operation is extremely simple, and the sealing effect is better, effectively preventing water from escaping to non-target depths.

[0117] 2) Active root induction: By precisely controlling the depth of water infiltration, the growth direction of vegetation roots is actively and accurately guided, forcing the roots to penetrate deeper into the soil in search of water, which greatly enhances the drought resistance and stability of vegetation.

[0118] 3) Water saving and efficiency improvement: It avoids the large-scale flooding and water evaporation loss of traditional irrigation, and delivers water directly to the target soil layer, which greatly improves water use efficiency and reduces the number of irrigations and total water consumption.

[0119] 4) Improved survival rate: Deep root systems can better utilize the stable moisture in deep soil, significantly improving the survival rate and growth vigor of vegetation in extreme drought conditions, and reducing the cost of replanting later.

[0120] 5) Significant ecological benefits: Vegetation with deep root systems has a stronger ability to fix sand and a more stable ecosystem, which can accelerate the process of desert ecological restoration, effectively reduce the harm of wind and sand, and has long-term ecological and social benefits.

[0121] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for inducing root infiltration in psammophytic vegetation, characterized in that, Includes the following steps: a. Site selection and land preparation Select a relatively flat area in the desert, remove stones and dead branches with a diameter greater than 5cm from the ground, level the land, and ensure that the slope is ≤5°. b. Digging a hole Dig planting pits (1) with a plant spacing of 2-3m and a row spacing of 3-4m. The diameter of the planting pit (1) is 50-60cm and the depth is 40-50cm. The bottom of the pit is leveled. c. Vegetation selection Select drought-resistant and salt-tolerant native sandy vegetation, requiring robust plants with prominent taproots and root lengths ≥30cm; d. PVC pipe water supply system setup ① Pipe material selection: A PVC pipe (2) with a diameter of 20-25cm and a length of 2.1m is selected. Water seepage holes (201) with a diameter of 5-8mm are evenly opened on the pipe wall. Multiple water seepage holes (201) are distributed in a spiral shape along the pipe wall. The vertical distance between the center of the topmost water seepage hole (201) and the top of the PVC pipe (2) is 30cm, and the vertical distance between the centers of adjacent water seepage holes (201) is 30cm. ② Fixed-depth conversion: A support rod (301) is fixedly provided on the inner wall of the top opening of the PVC pipe (2). A fixed depth hook (302) is fixedly provided on the bottom surface of the support rod (301). A spring tongue (303) is in contact with the curved end of the fixed depth hook (302). The end of the spring tongue (303) away from the curved end is fixedly connected to the vertical section of the fixed depth hook (302). The fixed-depth hook (302) is connected to a fixed-depth rope, which is composed of 6 rope segments (401) of equal length connected in series by 6 hanging rings (402). One end of the rope segment (401) at the bottom of the fixed-depth rope is connected to a water-absorbing and expanding cylindrical block (5). The depth of the water-absorbing and expanding cylindrical block (5) is controlled by connecting different hanging rings (402) to the fixed-depth hook (302). ③ Installation method: The assembled PVC pipe (2) is vertically buried 20-30cm away from the planting pit (1), with the pipe opening 5-10cm above the ground. The bottom of the pipe does not need to be sealed. The pipe body should be kept at an appropriate distance from the plant roots to avoid damaging the roots. e. Vegetation planting and backfilling Place the selected plants upright in the planting pit (1), spread out their roots, then backfill the soil and gently compact it in layers to ensure that the roots are in close contact with the soil. After backfilling, water thoroughly to settle the roots. The amount of water should be about 1 / 2 to 2 / 3 of the pit volume, so that the soil moisture content around the roots reaches 15% to 20%. f. Layered water control operation In the initial stage, 3-5 months after planting: water is supplied to the shallow soil layer with a depth of 15-20cm through the top seepage hole (201) of the PVC pipe (2); Mid-term stage, 5-6 months after planting: Water is supplied to the soil portion at a depth of 45-50cm through the second highest perforation hole (201) of the PVC pipe (2); Later stage: Every 1-2 months, water is supplied to the soil at depths of 75-80cm, 105-110cm, 135-140cm and 165-170cm through the third, fourth, fifth and sixth high seepage holes (201) of PVC pipe (2).

2. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, The rope segment (401) is 28cm long and the inner diameter of the hanging ring (402) is 2.5cm, so that when each rope segment (401) is lowered, the water-absorbing and expanding cylindrical block (5) is lower than the seepage hole (201), ensuring that after irrigation, water is directly delivered to the soil at the corresponding depth through the seepage hole (201); The diameter of the water-absorbing and expanding cylindrical block (5) is smaller than the inner diameter of the PVC pipe (2) in the dry state; the water-absorbing and expanding cylindrical block (5) can expand rapidly after absorbing water, forming a tight sealing piston structure with the inner wall of the PVC pipe.

3. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, The water-absorbing and expanding cylindrical block (5) is prepared by the following steps: Take a cylindrical stone with a diameter of PVC pipe (2) inner diameter R-2cm and a height of 10cm, and attach a ring of water-absorbing and expanding sealing strip to the curved surface of the cylindrical stone. The dry thickness of the water-absorbing and expanding sealing strip is 1cm, and the thickness after water absorption and expansion is 2.3-2.8cm, ensuring that the wet water-absorbing and expanding cylindrical block (5) is tightly attached to the inner wall of the PVC pipe (2) to form a relatively sealed structure; the water-absorbing and expanding sealing strip is bonded to the side of the cylindrical block with melamine glue.

4. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, The f. stratified water control operation specifically includes the following steps: Initial stage: Inject 5-10L of water into the pipe through the opening of the PVC pipe (2), hang all the hanging rings (402) of the fixed depth rope on the fixed depth hook (302), and lock them with the spring tongue (303) to prevent them from falling off; the water-absorbing and expanding cylindrical block (5) quickly absorbs water and forms a relatively sealed structure with the inner wall of the PVC pipe (2), and under the action of gravity, it sinks to a depth of 32cm. The topmost seepage hole (201) leaks out of the hole with a radius of R+2cm. The water seeps into the shallow soil part with a depth of 15-20cm, and the seepage speed is relatively slow, which promotes the lateral development of the root system and increases the root diameter. Mid-term stage: Repeat the water injection operation, unload the first hanging ring (402), and let the water-absorbing and expanding cylindrical block (5) sink to a depth of 62.5cm. Then, let the second highest seepage hole (201) leak out of the hole with a radius of R+2.5cm. The seepage speed is slightly accelerated, and the water seeps into the soil to a depth of 45-50cm, which promotes the root system to develop along the depth and further penetrate down, that is, the root system length increases. Later stage: Subsequently, every 1-2 months, the second, third, fourth and fifth hanging rings (402) are unloaded and hung on the fixed-depth hooks (302). Each water injection can achieve precise fixed-depth water supply to the soil at depths of 75-80cm, 105-110cm, 135-140cm and 165-170cm. Each seepage hole (201) successively leaks out of the hole with a radius of R+3cm, R+3.5cm, R+4cm and R+4.5cm, and the gradient of the infiltration rate increases. During the non-drought period, the water supply frequency gradually increases from 3 days / time to 2.7 days / time, 2.3 days / time and 1.8 days / time. During the drought period, the water supply frequency doubles. The interval between each operation is adjusted according to the soil moisture and vegetation growth. By increasing the water supply depth in stages, the vegetation roots are continuously guided to follow the water to grow into the deeper soil.

5. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, When vegetation collapses or severe drought occurs, straighten the vegetation and fix it with a support; unload the five hanging rings (402) on the fixed depth hook (302) so that the water-absorbing expansion cylinder (5) is at the deepest point, and continuously add water at a flow rate of 1L / min. Within 1 minute, slowly stretch the fixed depth rope to make the water-absorbing expansion cylinder (5) the highest position, creating a vacuum in the PVC pipe (2) to absorb the gas in the soil. Then let it fall naturally so that the water gradually penetrates into the soil at each depth. Due to the previous soil vacuum state, the water quickly fills the soil. Continue the above operation until the soil moisture content near the PVC pipe (2) reaches 20-25%, then stop adding water.

6. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, During desert nights, a funnel-shaped film is installed above the PVC pipe (2) using a support frame, and the bottom of the funnel-shaped film has through holes, so that moisture in the desert air condenses on the surface of the film and flows into the PVC pipe (2), thus achieving nighttime water replenishment.

7. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, The PVC pipe (2) is covered with a layer of straw.

8. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, When sand adheres to the inner wall of the PVC pipe (2), add 5-8L of water, unload the five hanging rings (402) on the fixed depth hook (302) so that the water-absorbing expansion cylinder (5) is at the deepest point, then quickly stretch the fixed depth rope to make the water-absorbing expansion cylinder (5) the highest position, and use a vacuum cleaner to absorb the sand on the surface of the water-absorbing expansion cylinder (5).

9. The method for inducing root infiltration in psammophytic vegetation according to claim 1, characterized in that, When the moisture content of the deep soil at the bottom of the PVC pipe (2) is high, add 2-3L of water to make the water-absorbing and expanding cylindrical block (5) absorb water and expand. Unload the five hanging rings (402) on the fixed-depth hook (302) so that the water-absorbing and expanding cylindrical block (5) is located at the deepest point. Then, stretch and release the fixed-depth rope back and forth to use vacuum to draw underground moisture into the PVC pipe (2). Then, release it into the soil at different depths through each seepage hole (201) to achieve the change of soil gas humidity.

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