Black bamboo charcoal-based degradable mulching film as well as preparation method and application thereof

Abstract

The invention discloses a black bamboo charcoal-based degradable mulching film as well as a preparation method and application thereof, and belongs to the technical field of biodegradable materials. The mulching film is composed of poly (butylene adipate-co-terephthalate) (PBAT) and bamboo charcoal powder, and the bamboo charcoal powder is obtained by carbonizing bamboo powder. The core of the invention is that the technical bottlenecks that the original bamboo powder is strong in hydrophilicity, difficult to crush and poor in compatibility with PBAT are solved by utilizing carbonization modification, so that the use of color master batch and a coupling agent is omitted at the same time, and the cost is remarkably reduced. The prepared black mulching film not only has excellent mechanical properties, but also has multiple synergistic functions of blocking and preserving soil moisture, far infrared heating, shading and preventing weeds, improving soil, fixing carbon and the like, is an efficient and environment-friendly solution of replacing plastic with bamboo, and is suitable for the fields of agriculture and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biodegradable polymer composites, in particular to a black bamboo charcoal-based degradable mulch film and a preparation method and application thereof. BACKGROUND

[0002] The agricultural mulch covering technology can effectively conserve soil moisture, increase temperature and suppress weeds, and is crucial to ensuring stable and high yields in modern agriculture, and is known as the "white revolution" in agricultural production. However, the widely used traditional polyethylene (PE) mulch is chemically stable and difficult to degrade in nature, and its residual fragments accumulate in the soil year by year, remaining for hundreds of years. These residues can destroy the soil aggregate structure, hinder the transport of water and nutrients, and affect the growth of crop roots, leading to serious "white pollution", which has become a major environmental problem restricting the sustainable development of agriculture.

[0003] Polybutylene adipate terephthalate (PBAT) is a fully biodegradable aliphatic-aromatic copolyester, which has similar processing performance and mechanical properties to low-density polyethylene (LDPE), and can be finally decomposed into CO2 and water by microorganisms in the natural environment after use, and is considered as one of the most ideal substrates to replace PE mulch. However, there are two major defects in pure PBAT mulch: first, the raw material cost is much higher than PE, which restricts large-scale application; second, the finished product is a transparent film, which cannot meet the key demand of "light shielding and weed prevention" in agricultural production, and needs to be improved to adapt to the actual planting scene. Therefore, the development of filled PBAT mulch with light shielding and degradable properties has become the core research direction in the field of agricultural environmental protection materials.

[0004] In order to give PBAT mulch light shielding property, the existing technology generally uses the scheme of adding a large amount of black masterbatch (usually using carbon black as colorant). This method not only further increases the cost of raw materials, but also, as an inorganic filler, a large amount of carbon black will affect the mechanical properties (such as elongation at break) and the final degradation rate of the mulch, making it difficult to balance "economy" and "functionality". From the perspective of environmental protection and cost reduction, using natural, renewable and degradable biomass fillers to replace part of PBAT and all color masterbatch is a more attractive solution.

[0005] Bamboo powder is derived from natural bamboo, has the advantages of wide source, low cost, renewable, and complete biodegradability, and can theoretically realize the environmental protection concept of "bamboo instead of plastic", and play the role of bamboo fiber reinforcement. However, many years of research and practice have shown that direct use of raw bamboo powder to prepare PBAT mulch faces two major technical bottlenecks:

[0006] 1. Compatibility is extremely poor: The main components of raw bamboo powder are cellulose, hemicellulose and lignin, and the surface is rich in hydrophilic hydroxyl groups (-OH), while PBAT resin is a hydrophobic material, with significant difference in polarity, resulting in extremely weak interfacial bonding force, and easy to form phase separation. This structural defect will make the stress unable to be effectively transmitted from the PBAT matrix to the bamboo powder filler, seriously damaging the mechanical properties of the composite material, especially the toughness and elongation at break. The prior art needs to add coupling agents such as titanate and silane to improve compatibility (see patent CN107722449A), but this will increase the cost, complicate the formula, and may also introduce non-environmentally friendly substances, which goes against the original intention of "green and environmentally friendly".

[0007] 2. Poor processability: The lignin and other components in raw bamboo powder have extremely high toughness, making it extremely difficult to be ground to a high fineness of 800 mesh or more - the process is high in energy consumption, low in yield, and severely wears the equipment, resulting in high production cost and difficulty in achieving industrial scale production. When coarser bamboo powder (such as 200-400 mesh) is used as a filler, stress concentration points are easily formed in the PBAT matrix, further exacerbating the deterioration of the mulch performance.

[0008] Although the prior art has explored the above problems, it has not broken through the traditional thinking mode. For example, the patent of Fujian Yangzhu New Material Technology Co., Ltd. (CN120082181A) uses "inorganic lye impregnation and acyl halide reagent modification" of bamboo powder, and uses special "compatibilizing grafting agent" in conjunction; its another patent (CN120272025A) modifies bamboo fiber through "grid-like grafting product". These schemes all rely on complex chemical modification process, long process, high cost, and may involve toxic reagents, which deviates from the original intention of environmental protection; at the same time, its core goal is still limited to "improving compatibility", without considering the possibility of omitting the additive through the characteristics of the material itself.

[0009] Although bamboo charcoal powder has been used in the fields of adsorption and textiles, when it is used in biodegradable mulch, the prior art either only regards it as an ordinary filler without exploring its potential to replace additives, or still adds coupling agents (such as patent CN118812988A). So far, there is no technology to disclose the key step of "carbonization modification" to fundamentally change the physical and chemical properties of bamboo powder, and to solve the three major problems of compatibility, processability and coloring at one time, and to achieve the element omission invention of "omitting coupling agent and color master batch".

[0010] In summary, the present application proposes a biodegradable mulch that can fundamentally solve the compatibility problem of biomass filler and PBAT, without relying on color master batch and coupling agent, with simple process, low cost and multiple functions. SUMMARY

[0011] The black bamboo charcoal-based degradable mulching film has the advantages of simple formula, low cost, multiple functions and environmental friendliness.

[0012] To achieve the above object, the present application adopts the following technical solutions:

[0013] A black bamboo charcoal-based degradable mulching film comprises the following components in parts by weight:

[0014] Polybutylene adipate / terephthalate (PBAT): 70-90 parts;

[0015] Bamboo charcoal powder: 10-30 parts;

[0016] The bamboo charcoal powder is obtained by carbonizing treatment of bamboo powder.

[0017] Further, the particle size of the bamboo charcoal powder is 500-5000 mesh.

[0018] Further, the particle size of the bamboo charcoal powder is 1000-2500 mesh.

[0019] Further, the particle size of the bamboo charcoal powder is 1500-2000 mesh.

[0020] A preparation method of a black bamboo charcoal-based degradable mulching film comprises the following steps:

[0021] S1. Carbonization: carbonize bamboo powder at 200-400 DEG C to obtain bamboo charcoal;

[0022] S2. Grinding: grind and classify the bamboo charcoal to obtain bamboo charcoal powder with a target particle size;

[0023] S3. Blending: dry blend the bamboo charcoal powder with PBAT resin, and no color master batch or coupling agent is added in the process;

[0024] S4. Pelletizing: melt blend, extrude, cool and pelletize the blended material obtained in step S3 by a double-screw extruder to obtain bamboo charcoal-PBAT composite master batch;

[0025] S5. Film blowing: blow mold the composite master batch obtained in step S4 by a film blowing machine to prepare the black bamboo charcoal-based degradable mulching film.

[0026] Further, the carbonization treatment in step S1 is carried out in a rotary kiln, and the carbonization process is oxygen-lacking carbonization, and the carbonization time is 1-3 hours.

[0027] Further, the processing temperature range of the double screw extruder in step S4 is 150 DEG C ~ 180 DEG C, the temperature gradient from the feeding port to the head is set as 150 DEG C → 165 DEG C → 170 DEG C → 175 DEG C → 170 DEG C, and the main machine rotating speed is 180 ~ 220 r / min.

[0028] Further, the processing temperature range of the film blowing forming in step S5 is 160 DEG C ~ 185 DEG C, the temperature gradient from the feeding section to the die port is set as 165 DEG C → 170 DEG C → 175 DEG C → 180 DEG C, the blowing ratio is 2.0 ~ 3.0, the traction speed is 8 ~ 12 m / min, and the prepared mulching film thickness is 0.010 mm ~ 0.020 mm.

[0029] The application of a black bamboo charcoal-based degradable mulching film in agricultural cultivation is used for covering soil to achieve the purposes of blocking water vapor evaporation and preserving soil moisture, emitting far infrared rays to increase temperature, shading to prevent weeds, and finally degrading to improve soil and fix carbon in the form of bamboo charcoal particles.

[0030] The beneficial effects of the present application are:

[0031] 1. Element omission and cost reduction: the natural black of bamboo charcoal powder replaces color master batches, and the compatibility of bamboo charcoal powder and PBAT is improved by carbonization modification to omit coupling agents, which not only simplifies the formula (only contains two core components of PBAT and bamboo charcoal powder), but also reduces the cost of raw materials and the environmental risk brought by auxiliary agents;

[0032] 2. Multiple functions and synergistic effect: the prepared mulching film integrates the five functions of "soil moisture preservation, temperature increase, light shading to prevent weeds, soil improvement, and carbon fixation", breaks through the limitation of "single function" of traditional mulching film, can adapt to the needs of agricultural production in all directions, and improves crop yield and quality;

[0033] 3. Environmentally friendly and sustainable: the product is fully biodegradable, finally decomposes into CO2 and water, and the bamboo charcoal particles remaining in the soil can improve the soil quality, completely eliminate white pollution, and meet the concept of circular agriculture;

[0034] 4. Feasible process and easy industrialization: the high brittleness of carbonized bamboo powder reduces the difficulty of crushing, and the energy consumption is significantly reduced; and the whole preparation process is fully compatible with the existing plastic processing equipment, and can realize large-scale production without modifying the production line, so the popularization prospect is broad. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor.

[0036] Figure 1 Flow chart for the preparation process of the present application;

[0037] Figure 2 Schematic diagram of the application effect of the mulch in farmland. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] A black bamboo charcoal-based degradable mulch, comprising the following components by weight:

[0040] Polybutylene adipate / terephthalate (PBAT): 70-90 parts; PBAT serves as the base material, providing the basic mechanical properties and degradability of the mulch, and its processing performance is similar to PE, and it can be completely degraded by microorganisms, meeting the environmental protection requirements;

[0041] Bamboo charcoal powder: 10-30 parts; the bamboo charcoal powder is obtained by carbonizing treatment of bamboo powder, and its functions include: ①replacing black masterbatch to give the mulch light-shielding property; ②improving the compatibility with PBAT and omitting coupling agent; ③giving the mulch far-infrared warming, soil improvement after degradation and carbon sequestration function.

[0042] A preparation method of the mulch, comprising the following steps:

[0043] S1. Carbonization: send the bamboo powder into a rotary kiln, first dry at 180-220℃ for 1-2 hours (remove free water in the bamboo powder to avoid gas bubbles in the carbonization process), then perform oxygen-deficient carbonization at 200-400℃ for 1-3 hours, and obtain bamboo charcoal blocks after cooling. The rotary kiln is selected for carbonization because it can realize uniform heating and continuous production of bamboo powder, adapting to the industrialization demand; oxygen-deficient carbonization can avoid bamboo powder burning, ensuring carbonization efficiency and bamboo charcoal quality.

[0044] S2. Pulverization: send the bamboo charcoal blocks into an air flow pulverizer for pulverization, and screen through a classifier to obtain bamboo charcoal powder with a target particle size (500-5000 mesh). Compared with the original bamboo powder, the carbonized bamboo charcoal has significantly improved brittleness, is easier to obtain high-mesh powder through air flow pulverization, reduces energy consumption by more than 30%, and has better powder dispersibility.

[0045] S3. Blending: Pour the bamboo charcoal powder and PBAT resin into a high-speed mixer and dry mix at a speed of 700-900 r / min for 4-6 minutes to obtain a uniform blended material. No color masterbatch or coupling agent is added in this process. The natural black color of the bamboo charcoal powder can replace the color masterbatch. After carbonization, the surface hydroxyl groups of the bamboo charcoal powder are reduced, the hydrophobicity is increased, and the porous structure of the bamboo charcoal powder can increase the contact area with PBAT, achieving good compatibility without the need for additional coupling agents.

[0046] S4. Pelletizing: The blended material obtained in step S3 is fed into a twin-screw extruder for melt blending, extrusion, cooling, and pelletizing to obtain bamboo charcoal-PBAT composite masterbatch. The processing temperature of the twin-screw extruder is 150-180°C, and the temperature gradient from the feeding port to the die is preferably 150°C→165°C→170°C→175°C→170°C, and the main machine speed is 180-220 r / min. This temperature gradient design can ensure that PBAT is fully melted while avoiding excessive temperature that leads to PBAT degradation; the speed control can ensure uniform mixing of the bamboo charcoal powder and PBAT, preventing material aggregation.

[0047] S5. Film blowing: The composite masterbatch obtained in step S4 is fed into a single-screw film blowing machine for blow molding to produce the black bamboo charcoal-based degradable mulch film. The processing temperature for film blowing is 160-185°C, and the temperature gradient from the feeding section to the die is preferably 165°C→170°C→175°C→180°C; the blow-up ratio is 2.0-3.0, and the pulling speed is 8-12 m / min, and the thickness of the produced mulch film is 0.010-0.020 mm. The coordinated control of the blow-up ratio and the pulling speed can ensure uniform thickness and stable mechanical properties of the mulch film, meeting the needs of agricultural covering.

[0048] The application of the black bamboo charcoal-based degradable mulch film in agricultural cultivation is as follows: covering the mulch film on the surface of the crop planting soil can achieve multiple functions:

[0049] Barrier to water vapor evaporation to conserve soil moisture: The dense structure of the mulch film can reduce soil water evaporation, and the water evaporation inhibition rate can reach 58-62% through testing;

[0050] Emission of far infrared rays to increase temperature: Bamboo charcoal powder has good far infrared radiation performance, which can increase soil temperature, with a daily average temperature increase of 2.1-2.5°C, especially in low temperature seasons, which can promote crop germination and growth;

[0051] Light blocking to prevent weeds: The high light-blocking property of bamboo charcoal powder (light-blocking rate > 99%) can inhibit the photosynthesis of weeds, reduce weed growth, and reduce the use of pesticides;

[0052] Degradation and soil improvement: The mulch film can be completely degraded in the natural environment, and the residual bamboo charcoal particles can improve the soil permeability and fertility, while achieving biomass carbon sequestration, in line with the concept of circular agriculture.

[0053] Example 1: Preparation of 2000 mesh bamboo charcoal powder and mulch film

[0054] 1. Carbonization: Put 10-30 mesh bamboo powder into a rotary kiln, first dry at 200°C for 1 hour, then carbonize at 400°C for 2 hours in an oxygen-free environment. After cooling, get bamboo charcoal blocks.

[0055] 2. Powdering: Put the bamboo charcoal blocks into an air jet mill for pulverization, and collect the ultra-fine bamboo charcoal powder with a particle size of about 2000 mesh (D50 = 6.5 μm) through a classifier.

[0056] 3. Blending: Take 20 parts by weight of the above-mentioned bamboo charcoal powder and 80 parts by weight of PBAT resin (brand: ), pour into a high-speed mixer, dry mix at 800 r / min for 5 minutes, get a uniform blend.

[0057] 4. Granulation: Put the mixed material into a co-rotating twin-screw extruder for melt blending and granulation. The temperature of the extruder from the feeding port to the head is set at 150°C, 165°C, 170°C, 175°C, 170°C, and the main machine speed is 200 r / min. The melt-extruded strip is cooled in a water tank, and then cut into cylindrical composite pellets with a diameter of about 3 mm and a length of about 3 mm by a pelletizer.

[0058] 5. Film blowing: Put the composite pellets into a single-screw film blowing machine for blow molding. The film blowing temperature from the feeding section to the die is set at 165°C, 170°C, 175°C, 180°C. The blow ratio is 2.5, and the pulling speed is 10 m / min. Finally, a black bamboo charcoal-based degradable mulch film with a thickness of 0.012 mm and a folding diameter of 1000 mm is prepared.

[0059] Example 2: Preparation of 1500 mesh bamboo charcoal powder and mulch film

[0060] 1. Carbonization: Same as Example 1.

[0061] 2. Powdering: Adjust the parameters of the air jet mill and the classifier, and collect the bamboo charcoal powder with a particle size of about 1500 mesh (D50 ≈ 10 μm).

[0062] 3. Blending: Take 15 parts by weight of 1500 mesh bamboo charcoal powder and 85 parts by weight of PBAT resin, and mix according to the same steps as Example 1.

[0063] 4. Granulation and film blowing: The process parameters are the same as Example 1, and finally a mulch film with a thickness of about 0.014 mm is prepared.

[0064] Example 3: Preparation of 1000 mesh bamboo charcoal powder and mulch film

[0065] 1. Carbonization: same as Example 1.

[0066] 2. Pulverization: adjust parameters, collect bamboo charcoal powder with particle size of about 1000 mesh (D50≈13 μm).

[0067] 3. Blending: take 25 parts by weight of 1000 mesh bamboo charcoal powder and 75 parts by weight of PBAT resin, and mix according to the same procedure as Example 1.

[0068] 4. Pelletization and film blowing: the process parameters are the same as Example 1, and finally a mulch film with a thickness of about 0.016 mm is prepared.

[0069] Example 4: Test of soil moisture conservation effect of mulch film

[0070] Take the mulch film sample prepared in Example 1, and test the soil moisture evaporation inhibition rate according to the standard GB / T 2540-2015. Set up a mulched group and a bare control group, each with 3 replicates. Place 500g of standard soil (moisture content 20%) in the same size container, and cover the mulched group completely with the mulch film, and do not cover the control group. After 72 hours of placement under the conditions of temperature 25℃ and humidity 50%, measure the soil moisture content.

[0071] Test results: the soil moisture content of the mulched group is 17.8%, and the soil moisture content of the control group is 9.2%. The calculated water evaporation inhibition rate is 62.3%, indicating that the mulch film of the application has excellent soil moisture conservation performance.

[0072] Example 5: Test of warming effect of mulch film

[0073] Take the mulch film sample prepared in Example 1, and conduct a field plot test. Set up a mulched group and a bare control group, each with 3 replicates, and the plot area is 1m x 1m. Use a digital temperature recorder to continuously monitor the soil temperature at a depth of 5cm, and record the temperature at 6:00, 12:00 and 18:00 every day for 7 consecutive days.

[0074] Test results: the average daily soil temperature of the mulched group is 22.3℃, and the average daily soil temperature of the control group is 19.8℃, with an average warming effect of 2.5℃. In particular, the warming effect at 12:00 is most significant, reaching 4.2℃. This indicates that the mulch film of the application has a significant far infrared warming effect.

[0075] Comparative Example 1 (using original bamboo powder)

[0076] The raw materials, ratio and process conditions were the same as in Example 1, except that "2000 mesh bamboo charcoal powder" was replaced by "2000 mesh raw bamboo powder" (obtained by the same mechanical grinding). It was found that due to the poor compatibility of raw bamboo powder with PBAT, the blend was severely agglomerated in the extruder, the melt pressure fluctuated greatly, and the extrusion granulation was not smooth, so the experiment was stopped.

[0077] Comparative Example 2 (using coarse bamboo charcoal powder)

[0078] The raw materials, ratio and process conditions were the same as in Example 1, except that "2000 mesh bamboo charcoal powder" was replaced by "400 mesh bamboo charcoal powder". The obtained mulch film had obvious white spots (PBAT matrix) and black particles on the surface, and the hand feeling was rough.

[0079] Comparative Example 3 (adding coupling agent)

[0080] On the basis of Example 1, during the blending process in step S3, 1.5% by weight of silane coupling agent (KH550) was additionally added to the bamboo charcoal powder. The remaining conditions were unchanged.

[0081] Performance test and results

[0082] The mulch film samples prepared in Examples 1-3 and Comparative Examples 2-3 were subjected to performance tests, and the test results are shown in the following table:

[0083] Table 1 Performance test results

[0084]

[0085] From the above test data, it is fully proved that:

[0086] 1. Carbonization is a key prerequisite: Comparative Example 1 shows that raw bamboo powder that has not been carbonized cannot be used in this process.

[0087] 2. Particle size is an important parameter: Example 1 (2000 mesh) has the best overall performance, and Comparative Example 2 (400 mesh) has the worst performance, indicating that the particle size of bamboo charcoal powder significantly affects the mechanical properties and apparent quality of the mulch film. The finer the particle size, the better the dispersibility and the better the performance of the mulch film.

[0088] 3. The present application can omit the coupling agent: Comparison of the data of Example 1 and Comparative Example 3 shows that using the ultrafine bamboo charcoal powder of the present application, without adding a coupling agent, the mechanical properties of the prepared mulch film are comparable to those of the sample with added coupling agent, proving the feasibility of omitting the coupling agent, while reducing the cost.

[0089] 4. Significant effect of soil conservation and temperature increase: The mulch film of the present application has excellent water retention capacity (inhibition rate 62.3%) and temperature increase effect (average temperature increase 2.5°C), fully meeting the needs of agricultural production.

[0090] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A black bamboo charcoal-based degradable mulch film, characterized in that, By weight parts, comprising the following components: Polybutylene adipate / terephthalate (PBAT): 70-90 parts; Bamboo charcoal powder: 10-30 parts; The bamboo charcoal powder is obtained by carbonizing treatment of bamboo powder.

2. The black charcoal-based degradable mulch film according to claim 1, characterized in that: The particle size of the bamboo charcoal powder is 500-5000 mesh.

3. The black charcoal-based degradable mulch film according to claim 2, characterized in that: The particle size of the bamboo charcoal powder is 1000-2500 mesh.

4. The black charcoal-based degradable mulch film according to claim 3, characterized in that: The particle size of the bamboo charcoal powder is 1500-2000 mesh.

5. A method for preparing the black bamboo charcoal-based degradable mulch film according to any one of claims 1 to 4, characterized in that, Comprising the following steps: S1. Carbonization: carbonize the bamboo powder at 200-400°C to obtain bamboo charcoal; S2. Crushing: crush and classify the bamboo charcoal to obtain bamboo charcoal powder with a target particle size; S3. Blending: dry blend the bamboo charcoal powder with PBAT resin, without adding color masterbatch and coupling agent; S4. Pelletizing: melt blend, extrude, cool, and pelletize the blended material obtained in step S3 by a twin-screw extruder to obtain bamboo charcoal-PBAT composite masterbatch; S5. Film blowing: blow mold the composite masterbatch obtained in step S4 by a film blowing machine to produce the black bamboo charcoal-based degradable mulch film.

6. The preparation method according to claim 5, characterized in that, The carbonization process in step S1 is carried out in a rotary kiln, and the carbonization process is oxygen-deficient carbonization, with a carbonization time of 1-3 hours.

7. The preparation method according to claim 5, characterized in that, The processing temperature of the twin-screw extruder in step S4 is 150-180°C, and the temperature gradient from the feeding port to the die head is set to 150°C→165°C→170°C→175°C→170°C, with a main machine speed of 180-220 r / min.

8. The preparation method according to claim 5, characterized in that, The processing temperature of the film blowing in step S5 is 160-185°C, and the temperature gradient from the feeding section to the die port is set to 165°C→170°C→175°C→180°C; the blow ratio is 2.0-3.0, the pulling speed is 8-12 m / min, and the thickness of the produced mulch film is 0.010-0.020 mm.

9. The use of the black bamboo charcoal-based degradable mulching film according to any one of claims 1 to 4 in agricultural cultivation, characterized in that, For the purpose of covering soil to achieve the functions of blocking water vapor evaporation and preserving soil moisture, emitting far infrared rays to increase temperature, shading to prevent weeds, and finally degrading into bamboo charcoal particles to improve soil and sequester carbon. For the purpose of covering soil to achieve the functions of blocking water vapor evaporation and preserving soil moisture, emitting far infrared rays to increase temperature, shading to prevent weeds, and finally degrading into bamboo charcoal particles to improve soil and sequester carbon.

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