Salinized soil improvement system and method for constructing vertical flow channel and leaching in frequency division mode

Abstract

The invention provides a saline soil improvement system and method for constructing a vertical flow channel and performing fractional-frequency leaching, the system comprises a physical barrier breaking layer, the vertical flow channel, a fractional-frequency leaching water supply system and an earth surface evaporation-inhibiting salt-controlling layer, specifically, a target land parcel to be improved is deeply ploughed to form the physical barrier breaking layer, then drilling is performed to form the vertical flow channel, and the physical barrier breaking layer is formed by the vertical flow channel and the fractional-frequency leaching water supply system. A vertical dominant flow channel network penetrating through the water blocking layer is constructed, irrigation and leaching are conducted at least three times with the decreasing water amount by means of the irrigation water frequency, after irrigation and leaching are completed, a plastic film is covered to form a ground surface evaporation restraining and salt controlling layer, water evaporation and salt return are restrained, and improvement is completed. According to the method, a vertical flow channel is constructed, a rapid channel for salt to flow downwards is physically opened, the problem of upper blocking and lower flooding caused by a water blocking layer is fundamentally solved, the salt discharging efficiency is high, water resources are saved by adopting a frequency division leaching mode, the salt return phenomenon is effectively inhibited by matching with plastic film covering after leaching, and the improvement achievement is consolidated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of saline-alkali soil improvement, and particularly relates to a saline-alkali soil improvement system and method for constructing vertical flow channels and frequency division leaching. BACKGROUND

[0002] In arid and semiarid regions, saline-alkali soil is widely distributed, and there are dense clayed layers or hardening layers in the soil profile of saline-alkali soil, which are physical properties of poor water resistance layers, and are the focus and difficulty of saline-alkali soil improvement. When facing such soil, the traditional method of salt leaching by irrigation often causes surface water accumulation, upper waterlogging and soil oxygen deficiency due to the difficulty of water infiltration, poor leaching effect, and even intensified surface salt return under strong evaporation.

[0003] The existing improvement measures mainly have two types: one is large-scale engineering measures, such as laying underground pipe drainage system, which has huge investment, complex construction and high maintenance cost, and is not suitable for popularization in all regions; the other is physical tillage measures, such as deep tillage and deep loosening, which can temporarily break the surface hardening layer, but has limited effect on deep and heavy clayed barrier layer, and cannot fundamentally solve the vertical drainage problem of the profile.

[0004] Existing research shows that the existence of water resistance layer is the fundamental reason for the blockage of water and salt migration and the low leaching efficiency. How to economically and efficiently establish vertical drainage paths through the water resistance layer without large-scale pipe engineering, and cooperate with accurate water regulation and control to realize efficient leaching of salt, is a technical problem to be solved in the field of saline-alkali soil improvement.

[0005] Based on this, a saline-alkali soil improvement system and method for constructing vertical flow channels and frequency division leaching are proposed. SUMMARY

[0006] The technical problem to be solved by the application is to provide a saline-alkali soil improvement system and method for constructing vertical flow channels and frequency division leaching to solve the problems in the background art.

[0007] To solve the above technical problems, the technical scheme adopted by the application is: In a first aspect, a saline-alkali soil improvement system for constructing vertical flow channels and frequency division leaching includes: A physical barrier layer is a loose soil layer formed by deep tillage of saline-alkali soil by external force; A vertical flow channel is provided at equal intervals below the physical barrier layer, and the adjacent vertical flow channels are clayed water resistance layers, and the bottom of the vertical flow channel is a underlying permeable layer; A frequency division leaching water supply system is specifically a frequency division leaching water supply system, which is realized by using irrigation water frequency to at least perform three times of irrigation leaching with decreasing water quantity through surface irrigation facilities. A surface evaporation control salt layer, which is a plastic film laid on the physical barrier layer, is laid after the irrigation leaching is completed.

[0008] As a further illustration of the present application, the depth of the physical barrier layer is 60 cm.

[0009] As a further illustration of the present application, the vertical flow channel is specifically a vertical hole with a diameter of 10-15 cm penetrating the water-blocking layer, and the vertical hole is filled with coarse sand or fine gravel.

[0010] As a further illustration of the present application, the vertical flow channels are arranged in a chessboard or plum blossom pattern at an interval of 150-250 cm.

[0011] In a second aspect, a method for improving saline soil by constructing a vertical flow channel and frequency division leaching uses the saline soil improvement system for constructing a vertical flow channel and frequency division leaching as in the first aspect, and comprises the following steps: First, deep plowing is performed on the target land to be improved to a depth of 60 cm to form a physical barrier layer, and then a vertical flow channel is drilled to form a vertical advantage flow channel network penetrating the water-blocking layer; At least three irrigation leachings are performed using irrigation water with a frequency of decreasing water volume, the first irrigation leaching is used for saturation and dissolution, and the last two irrigation leachings are used for displacement and cleaning of residual salt, and after the irrigation leaching is completed, a plastic film is laid to form a surface evaporation control salt layer to inhibit water evaporation and salt migration, and the improvement is completed.

[0012] Compared with the prior art, the present application has the following advantages: The present application physically opens a fast channel for salt downward movement by constructing a vertical flow channel, fundamentally solves the problem of "upper blockage and lower flooding" caused by the water-blocking layer, has high salt discharge efficiency, adopts a frequency division leaching mode, accurately controls the water volume according to the mechanism of "dissolution-displacement-cleaning", saves water resources compared with traditional flood irrigation, improves water use efficiency, and compared with expensive underground drainage engineering, the deep plowing and sand column construction technology used in the present application has low cost, easy-to-obtain materials, and convenient construction, is suitable for large-area popularization, effectively inhibits the salt return phenomenon after leaching, consolidates the improvement results, and creates a persistent and stable low-salt environment for crop growth. BRIEF DESCRIPTION OF DRAWINGS

[0013] Fig. 1 is a sectional view of the overall structure of the present application; Fig. 2 is a top view of the vertical flow channel arrangement structure of the present application; Fig. 3 is a schematic diagram of the irrigation leaching process of the present application.

[0014] Reference signs: 1-Physical barrier layer; 2-Clay water-blocking layer; 3-Vertical flow channel; 4-Underlying permeable layer; 5-Surface evaporation control and salt control layer; 6-Irrigation water; 7-Salt-containing leaching water. DETAILED DESCRIPTION

[0015] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the described examples are only a part of the embodiments of the present application, not all the embodiments, and the specific examples described herein are only used to explain the present application, and not to limit the present application. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0016] As Figs. 1-3 shown, the present application provides a technical solution: a saline soil improvement system for constructing vertical flow channels and frequency division leaching, comprising: a physical barrier layer 1, a vertical flow channel 3, a frequency division leaching water supply system and a surface evaporation control and salt control layer 5, the physical barrier layer 1 is a loose soil layer formed by deep plowing of saline soil with external force; a plurality of vertical flow channels 3 are arranged at equal intervals below the physical barrier layer 1, the adjacent vertical flow channels 3 are clay water-blocking layers 2, the bottom of the vertical flow channel 3 is an underlying permeable layer 4, the frequency division leaching water supply system is specifically at least three times of irrigation leaching with decreasing water volume by using irrigation water 6 through surface irrigation facilities, the surface evaporation control and salt control layer 5 is a plastic film covering the physical barrier layer 1 above, which is laid after the completion of irrigation leaching. A profile structure of "upper loose and lower permeable" is constructed, which completely solves the physical barrier of water and salt infiltration. According to the kinetics of salt leaching, the frequency division leaching realizes the precise hydraulic control of "first sufficient dissolution, then efficient replacement, and finally clean washing", the irrigation water 6 carrying salt is laterally collected to the vertical flow channel 3 under the action of gravity, and is quickly discharged from the root layer along the vertical flow channel 3, realizing efficient salt discharge, and the final surface evaporation control and salt control layer 5 cuts off the driving force of salt return, ensuring the long-term improvement effect, which is economical and practical.

[0017] As a possible implementation in the present embodiment, the depth of the physical barrier layer 1 is 60 cm.

[0018] As a possible implementation in the present embodiment, the vertical flow channel 3 is specifically a vertical hole with a diameter of 10-15 cm penetrating the clay water-blocking layer 2, and the vertical flow channel 3 is filled with coarse sand or fine gravel, and the vertical flow channels 3 are arranged in a chessboard or plum blossom pattern with a spacing of 150-250 cm.

[0019] A saline soil improvement method for constructing vertical flow channels and frequency division leaching, comprising the following steps: First, the target land to be improved is deep ploughed to a depth of 60 cm to form a physical barrier layer 1, and then a vertical flow channel 3 is drilled, and coarse sand or fine gravel is filled in the vertical flow channel 3. Specifically, a mechanical drilling machine is used to drill holes at an interval of 2 meters x 2 meters in the target land to be improved, the hole diameter is 15 cm, and the depth must penetrate the water-blocking layer 2 and reach the underlying permeable layer 4. In this embodiment, the depth is 80-120 cm, the hole is filled with coarse sand with a particle size of 0.5-2 mm, and a vertical dominant flow channel network penetrating the water-blocking layer is constructed; Use irrigation water to perform at least three times of irrigation leaching with decreasing water volume, First saturated dissolution: the first irrigation is performed by irrigation water 6, and the irrigation volume is 400 m 3 / mu. The large water volume is used to fully saturate the physical barrier layer 1 and fully dissolve the salt accumulated in the physical barrier layer 1.

[0020] After an interval of 2-3 days, the second irrigation leaching is performed: the irrigation volume is 350 m 3 / mu. The clean water of this round of irrigation pushes the high-concentration salt-containing leaching water 7 formed in the first round downward and sideward, and forces it to quickly drain into the deep layer through the vertical flow channel 3.

[0021] After another interval of 2-3 days, the third irrigation leaching is performed: the irrigation volume is 200 m 3 / mu. The small water volume is used for the last “rinsing” of the physical barrier layer 1 to remove residual salt.

[0022] After the irrigation leaching is completed, a plastic film is covered to form a surface evaporation inhibition and salt control layer 5, the plastic film is a black plastic film with a thickness of not less than 0.008 mm, which inhibits water evaporation and salt back migration, and the improvement is completed. The problems of difficult leaching, low efficiency and high cost of saline soil containing water-blocking layer are solved, and the invention has the advantages of high efficiency, controllable cost and long-lasting effect, and is suitable for large-area popularization and application.

[0023] It should be further explained that the drawings and embodiments of the present application mainly describe and explain the concept of the present application. On the basis of this concept, the specific forms and settings of some connection relationships, position relationships, power mechanisms, power supply systems, hydraulic systems and control systems may not be completely described, but those skilled in the art can realize the above-mentioned specific forms and settings by using well-known methods on the premise of understanding the concept of the present application.

[0024] When an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0025] The terms "inner", "outer", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", or "outer" and the like, indicate relative positions after the apparatuses or components are positioned as shown in the drawings and are used only for ease of description and illustration, and do not connote or imply necessarily the referred apparatuses or components must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

[0026] For the convenience of description, spatial relative terms, such as "above", "upper", "top", "up", "down", "lower" and the like, can be used herein for the purpose of illustration and description only and are not intended to limit or confine the scope of the application to any particular orientation or configuration, unless otherwise specifically stated, and are intended to encompass different orientations of the device, except where otherwise explicitly limited, thereto.

[0027] The terms "first", "second", etc., are used herein only to describe various instances, categories, and processes, and cannot be construed as indicating or implying relative importance or a specific number of the technical features indicated thereby. Thus, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, and the meaning of "several" is one or more, unless otherwise specifically limited.

[0028] It should be noted that, in this document, the relational terms such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or apparatus that includes a list of elements does not only include those elements but also includes other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0029] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A system for improving saline soil by constructing vertical flow channels and performing frequency-division leaching, characterized in that, include; Physical barrier layer (1), the physical barrier layer (1) is a loose soil layer formed by deep plowing of saline soil using external force; Vertical flow channels (3) are set at equal intervals under the physical barrier layer (1). Adjacent vertical flow channels (3) are separated by a water-blocking layer (2), and the bottom of the vertical flow channels (3) is a permeable layer (4). The frequency-divided rinsing water supply system specifically refers to using surface irrigation facilities to carry out irrigation rinsing at least three times with decreasing water volume using irrigation water (6) in different frequencies. The surface evaporation and salt control layer (5) is a plastic film covering the physical barrier layer (1) and is laid after irrigation and leaching.

2. The saline soil improvement system for constructing vertical flow channels and frequency-divided leaching according to claim 1, characterized in that, The depth of the physical barrier layer (1) is 60cm.

3. The saline soil improvement system for constructing vertical flow channels and frequency-divided leaching according to claim 1, characterized in that, The vertical flow channel (3) is specifically a vertical hole with a diameter of 10-15cm that penetrates the adhesive water-blocking layer (2) and is filled with coarse sand or fine gravel.

4. The saline soil improvement system for constructing vertical flow channels and frequency-divided leaching according to claim 3, characterized in that, The vertical flow channels (3) are arranged in a checkerboard or plum blossom pattern at intervals of 150-250cm.

5. The saline soil improvement system for constructing vertical flow channels and frequency-division leaching according to claim 1, characterized in that, The thickness of the plastic film is not less than 0.008 mm.

6. A method for improving saline soil by constructing vertical flow channels and performing frequency-division leaching, using a saline soil improvement system for constructing vertical flow channels and performing frequency-division leaching as described in any one of claims 1-5, characterized in that, Includes the following steps: First, the target plot to be improved is deeply cultivated to a depth of 60cm to form a physical barrier layer (1). Then, holes are drilled to form vertical flow channels (3). Coarse sand or fine gravel is filled into the vertical flow channels (3) to construct a vertical dominant flow channel network that penetrates the water barrier layer. The irrigation water frequency is reduced to carry out at least three irrigation leachings. The first irrigation leaching is used for saturation dissolution, and the next two irrigation leachings are used to promote replacement and clean residual salt. After the irrigation leaching is completed, a plastic film is covered to form a surface evaporation and salt control layer (5) to inhibit water evaporation and salt migration, thus completing the improvement.

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