Soil improvement material for ecologically restoring difficult site conditions as well as preparation method and application of soil improvement material

Abstract

The invention provides a soil improvement material for ecologically restoring difficult site conditions and a preparation method and application thereof.The soil improvement material capable of being used for plant planting comprises a slow-release capsule coating body, the slow-release capsule coating body is composed of three layers of capsules which are coaxially arranged at intervals, an inner cavity of the inner layer capsule is filled with a fiber drying agent, and the inner layer capsule is filled with a fiber drying agent; a composite material capable of exploding after absorbing soil moisture is filled between the inner-layer capsule and the middle-layer capsule, and dry sand grains are filled between the middle-layer capsule and the outer-layer capsule; the preparation method comprises the following steps: rolling a fiber drying sheet into a solid cylinder structure with a set diameter, tightening the solid cylinder structure with plant fibers to obtain a roll-type plant fiber drying agent, then loading the roll-type plant fiber drying agent into an inner-layer capsule, sealing the inner-layer capsule, and then coating the inner-layer capsule with a composite material and dry sand grains. The soil conditioner can be used for soil improvement in an area with a deep soil layer, and the air permeability and the loose state of the soil can be kept for a long time.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement technology, specifically relating to a soil improvement material for ecological restoration of difficult site conditions, its preparation method, and its application. Background Technology

[0002] Difficult site conditions refer to the combination of ecological and environmental factors on the land that are of great significance to the survival and growth of plants. These factors constitute a series of limiting factors that are unfavorable to plant growth, including: topographic factors, soil factors (such as poor soil, excessive salt or toxic substances, poor drainage, poor aeration or poor water retention), hydrological factors, climatic factors, biological factors, and human factors.

[0003] For areas with poor drainage and aeration, soil improvement is usually necessary for more efficient crop cultivation or ecological restoration. Currently, a common technical approach in these areas is to increase aeration. For example, document CN104186055B discloses a method for improving clayey soil. During rotary tillage, a mixture of fine sand and sawdust is mixed into the soil at a 1:1 ratio. 150-300 kg of this mixture is applied per acre, and the soil is tilled to a depth of at least 30 cm. This process transforms the highly clayey soil into a loose, well-aerated, and water-retentive cultivation substrate.

[0004] However, the aforementioned solutions are mainly suitable for shallow soil improvement (no more than 30cm from the surface). They are not very effective when used in deeper soil areas, especially since it is difficult to maintain the soil's permeability for a long time during use. Summary of the Invention

[0005] At least in order to solve the technical problems mentioned in the background art, the present invention aims to provide a soil amendment material for ecological restoration of difficult site conditions, its preparation method, and its application.

[0006] The present invention adopts the following technical solution.

[0007] A soil amendment material for ecological restoration of difficult site conditions includes a slow-release capsule body, which consists of three coaxially spaced capsules. The inner capsule cavity is filled with a fiber desiccant, the space between the inner and middle capsules is filled with a composite material that can "explode" after absorbing soil moisture, and the space between the middle and outer capsules is filled with dry sand particles. The composite material is obtained by uniformly mixing popping candy particles and wood ash at a volume ratio of 2 to 2.5:1.

[0008] Preferably, the particle size of the dry sand is not less than 0.2 mm and not more than 0.5 mm, and the moisture content of the dry sand is 4-5%; the particle size of the popping candy granules is 2-3 mm.

[0009] Furthermore, the inner cavity of the inner capsule is also filled with fertilizer granules, the volume of which does not exceed 1 / 3 of the inner cavity volume of the inner capsule.

[0010] Preferably, the wall thickness of each capsule layer is 0.15 mm, the inner diameter of the inner capsule layer is 10 mm, the inner cavity of the middle capsule layer is 20 mm, and the inner cavity of the outer capsule layer is 30 mm.

[0011] To better maintain soil aeration over a longer period, the fiber desiccant uses a cylindrical structure made of rolled fiber drying sheets.

[0012] The aforementioned method for preparing soil amendment materials includes the following steps: Step 1: Roll the fiber drying sheet into a solid cylindrical structure of a set diameter and tie it tightly with plant fiber filaments to obtain a rolled plant fiber desiccant. Then, put the rolled plant fiber desiccant into the inner capsule and seal it. Step 2: Fill the middle capsule with a predetermined amount of composite material and fix the middle capsule while keeping it open; then insert the inner capsule processed in Step 1 into the middle capsule by spinning until the composite material completely covers the inner capsule, and then seal the middle capsule. Step 3: Fill the outer capsule with a predetermined amount of dry sand and fix the outer capsule while keeping it open; then insert the middle capsule processed in Step 2 into the outer capsule by spinning until the dry sand completely covers the middle capsule, and then seal the outer capsule to obtain the soil amendment material.

[0013] Preferably, the volume of the composite material is 1.2 times the volume of the inner capsule, the volume of the dry sand is 1.3 times the volume of the middle capsule, and the rotation control during the spinning process is 120 revolutions per minute.

[0014] In the application of the aforementioned soil amendment materials in plant cultivation, in the early stage of plant cultivation, soil amendment materials with a length of 60-80cm are vertically buried in the soil, with the top of the soil amendment material level with the ground surface and the distance between the soil amendment material and the main root of the plant 8-10cm.

[0015] Beneficial effects: The soil amendment material in this invention can be used not only for shallow soil amendment, but also for soil amendment in deeper soil layers. The key is that it can maintain the soil's permeability and looseness for a long time. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the soil amendment materials in the embodiments; Figure 2 This is a schematic diagram of the preparation process of the soil amendment material in the example. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0018] Combination Figure 1 and Figure 2 As shown, a soil amendment material for ecological restoration of difficult site conditions includes a slow-release capsule body, which consists of three coaxially spaced capsules. The inner capsule 5 is filled with a fiber desiccant 6 (Dongguan Mingfeng brand). The fiber desiccant 6 is a cylindrical structure made of fiber desiccant sheets with a wall thickness of 0.8mm. The space between the inner capsule 5 and the middle capsule 3 is filled with a composite material 4 that can "explode" after absorbing soil moisture. The space between the middle capsule 3 and the outer capsule 1 is filled with dry sand particles 2. The composite material 4 is obtained by uniformly mixing popping candy particles and wood ash at a volume ratio of 2.2:1. Among them, the particle size of dry sand granules 2 is not less than 0.2 mm and not more than 0.5 mm, the moisture content of dry sand granules 2 is 4~5%, the particle size of popping candy granules is 2~3 mm; the wall thickness of each capsule layer is 0.15 mm, the inner diameter of the inner capsule 5 is 10 mm, the inner cavity of the middle capsule 3 is 20 mm, and the inner cavity of the outer capsule 1 is 30 mm.

[0019] The method for preparing soil amendment materials in this embodiment includes the following steps: Step 1: Roll the fiber drying sheet into a solid cylindrical structure of a set diameter and tie it tightly with plant fiber filaments to obtain the rolled plant fiber desiccant 6. Then, put the rolled plant fiber desiccant 6 into the inner capsule 5 and seal it. Step 2: Fill the middle capsule 3 with a predetermined amount of composite material 4. The volume of the predetermined amount of composite material 4 is 1.2 times the volume of the inner capsule 5. Fix the middle capsule 3 while keeping it open. Then, insert the inner capsule 5 processed in Step 1 into the middle capsule 3 by spinning. The rotation speed during the spinning process is controlled at 120 revolutions per minute until the composite material 4 completely covers the inner capsule 5. Then, seal the middle capsule 3. Step 3: Fill the outer capsule 1 with a predetermined amount of dry sand particles 2. The volume of the predetermined amount of dry sand particles 2 is 1.3 times the volume of the middle capsule 3. Fix the outer capsule 1 while keeping it open. Then, insert the middle capsule 3, which has been processed in Step 2, into the outer capsule 1 by spinning. The rotation speed during the spinning process is controlled at 120 revolutions per minute until the dry sand particles 2 completely cover the middle capsule 3. Then, seal the outer capsule 1 to obtain the soil amendment material.

[0020] Compared with Example 1, the difference is that the inner capsule 5 and the fiber desiccant 6 filling the inner cavity are replaced by a composite material 4 of equal volume.

[0021] Compared with Example 1, Example 2 differs in that the middle capsule 3 and the composite material 4 filling its cavity are replaced with an equal volume of fiber desiccant 6.

[0022] Compared with Example 1, Example 3 differs in that the inner capsule 5 and the middle capsule 3 and the material filling their cavities are all replaced with dry sand of equal volume. This scheme is similar to traditional sand-based soil improvement.

[0023] For soil (clay) in a site with difficult ecological restoration conditions, five experimental areas were selected. After removing debris, the soil amendment materials in Example 1 and the comparative examples were used for treatment (Example 1 corresponds to Experiment 1, Comparative Example 1 corresponds to Experiment 2, Comparative Example 2 corresponds to Experiment 3, No soil amendment corresponds to Experiment 4, and Comparative Example 3 corresponds to Experiment 5). The length of the soil amendment material used in Experiment 1 to Experiment 3 and Experiment 5 was 5 cm, and the burial depth was 40 cm from the top of the soil amendment material to the ground surface. The soil amendment material was buried vertically, and the soil oxygen content (i.e., soil oxygen content) at the top of the soil amendment material was monitored regularly using the same instrument. The results are shown in Table 1.

[0024] Table 1 Oxygen content in soil

[0025] As can be seen, the soil amendment material in Example 1 can be used for soil amendment in areas with deeper soil layers. The key is that it can maintain good soil aeration and looseness for 180 days after soil amendment, especially exhibiting excellent aeration performance between the 40th and 150th day after soil amendment. In contrast, the traditional soil probability scheme using sand can only maintain good aeration performance for 40 days. Example 2

[0026] A soil amendment material for ecological restoration of difficult site conditions, referring to Example 1, differs from Example 1 in that: the inner cavity of the inner capsule 5 is also filled with fertilizer granules, the volume of which accounts for 1 / 3 of the inner cavity volume of the inner capsule 5; the process of rolling the dried fiber sheet into a solid cylindrical structure of a set diameter is as follows: first, grooves are cut on the surface of the laid-out dried fiber sheet with a blade, then fertilizer powder granules are evenly sprinkled on the dried fiber sheet, and then it is rolled into a solid cylindrical structure.

[0027] In this embodiment, the application of soil amendment material in plant cultivation involves pre-planting soil amendment material with a length of 60-80cm vertically buried in the soil two months before planting. The top of the soil amendment material is level with the ground surface, and the distance between the soil amendment material and the main root of the plant is 8-10cm (the distance between the seed burial point and the soil amendment material during planting is 8-10cm). Example 3

[0028] A soil amendment material for ecological restoration of difficult site conditions, referring to Example 1, differs from Example 1 in that: composite material 4 is obtained by uniformly mixing popping candy particles and wood ash at a volume ratio of 2:1. Example 4

[0029] A soil amendment material for ecological restoration of difficult site conditions, referring to Example 1, differs from Example 1 in that: composite material 4 is obtained by uniformly mixing popping candy particles and wood ash at a volume ratio of 2.5:1.

[0030] In this invention, a specific material is encapsulated in multi-layered slow-release capsules with a specific structure, thus maintaining the soil's permeability for a long period. During use, when moisture in the soil comes into contact with the outer capsule 1, the outer capsule 1 begins to disappear, and after the outer capsule 1 disappears, the dry sand particles 2 initially disperse. Then, when the middle capsule 3 comes into contact with moisture in the soil, the middle capsule 3 begins to disappear. After the middle capsule 3 disappears, the composite material 4 absorbs a certain amount of moisture and exhibits an "explosion" phenomenon. During this process, the sand particles are further dispersed, but the fiber desiccant 6 does not expand yet, and some sand particles are pressed into the original soil. Subsequently, when the inner capsule 5 comes into contact with moisture and disappears, the fiber desiccant 6 gradually absorbs water and expands significantly radially, further pressing some sand particles into the original soil. As a result, the area where the soil amendment material is located exhibits a good permeability structure. Even during the degradation process of the fiber desiccant 6, the area where the soil amendment material is located will still exhibit a good permeability structure, avoiding the phenomenon of rapid re-closing of the soil amendment area (the soil permeability deteriorates in a short period of time), which is beneficial to plant root growth.

[0031] The overall inventive concept of this invention includes: using a solid cylindrical structure made of dried fiber sheets in combination with a capsule-encapsulated specific composite material 4, the composite material 4 first "explodes" to push sand particles into the original soil, and then the solid cylindrical structure made of dried fiber sheets absorbs water layer by layer from the outside to the inside and slowly expands, thereby continuing to push sand particles into the original soil over a long period of time, ultimately achieving the long-term maintenance of soil permeability and relaxation.

Claims

1. A soil amendment material for ecological restoration of difficult site conditions, comprising a slow-release capsule coating, characterized in that: The sustained-release capsule is composed of three coaxial and spaced-apart capsules. The inner capsule is filled with a fiber desiccant. The space between the inner and middle capsules is filled with a composite material that can "explode" after absorbing soil moisture. The space between the middle and outer capsules is filled with dry sand. The composite material is obtained by mixing popping candy particles and wood ash in a volume ratio of 2 to 2.5:

1.

2. The soil amendment material according to claim 1, characterized in that: The particle size of dry sand is not less than 0.2 mm and not more than 0.5 mm, and the moisture content of dry sand is 4-5%; the particle size of popping candy granules is 2-3 mm.

3. The soil amendment material according to claim 2, characterized in that: The inner capsule cavity is also filled with fertilizer granules, the volume of which does not exceed 1 / 3 of the inner capsule cavity volume.

4. The soil amendment material according to claim 3, characterized in that: Each capsule layer has a wall thickness of 0.15 mm, the inner diameter of the inner capsule is 10 mm, the inner cavity of the middle capsule is 20 mm, and the inner cavity of the outer capsule is 30 mm.

5. The soil amendment material according to any one of claims 1-4, characterized in that: The fiber desiccant uses a cylindrical structure made of rolled fiber desiccant sheets.

6. The method for preparing the soil amendment material according to any one of claims 1-5, characterized in that, step include: Step 1: Roll the fiber drying sheet into a solid cylindrical structure of a set diameter and tie it tightly with plant fiber filaments to obtain a rolled plant fiber desiccant. Then, put the rolled plant fiber desiccant into the inner capsule and seal it. Step 2: Fill the middle capsule with a predetermined amount of composite material and fix the middle capsule while keeping it open; then insert the inner capsule processed in Step 1 into the middle capsule by spinning until the composite material completely covers the inner capsule, and then seal the middle capsule. Step 3: Fill the outer capsule with a predetermined amount of dry sand and fix the outer capsule while keeping it open; then insert the middle capsule processed in Step 2 into the outer capsule by spinning until the dry sand completely covers the middle capsule, and then seal the outer capsule to obtain the soil amendment material.

7. The preparation method according to claim 6, characterized in that: The preset amount of composite material volume is 1.2 times the volume of the inner capsule, the preset amount of dry sand volume is 1.3 times the volume of the middle capsule, and the rotation control during the spinning process is 120 revolutions per minute.

8. The application of the soil amendment material as described in any one of claims 1-5 in plant cultivation, characterized in that: In the early stages of plant planting, soil amendment material with a length of 60-80cm is vertically buried in the soil, with the top of the soil amendment material level with the ground surface and the distance between the soil amendment material and the main root of the plant 8-10cm.

Images