CN111264260A - A kind of biodegradable plastic film covering planting method - Google Patents

Abstract

The invention discloses a method for planting biodegradable mulching films, which comprises the following steps: a planting test, in which a biodegradable mulching film is preliminarily selected according to the planting requirement of crops to be planted in an area to be planted, and a small-area first trial test is carried out, wherein the biodegradable mulching film is a multilayer biodegradable mulching film; selecting a mulching film, and determining a multilayer biodegradable mulching film required by crop planting in a planting area according to planting test matching; and (III) planting crops, namely, adopting matched multilayer biodegradable mulching films to carry out mulching film planting when the crops are formally planted in a planting area. The invention provides the technical requirements of the application of the biodegradable mulching film, can optimize the parameters of the mulching film, determine the suitable type of the biodegradable mulching film in the crop planting area and further promote the good growth of crops based on the innovative multi-layer biodegradable mulching film application function division and development of mulching film selection meeting the requirements of the environment and crops.

Description

A kind of biodegradable plastic film covering planting method

technical field

The invention relates to a method for covering planting with biodegradable plastic film, and belongs to the technical field of agriculture.

Background technique

Biodegradable mulch is an effective way to deal with "white pollution". In recent years, in Europe, Japan and other countries, the market share of biodegradable mulch film has been increasing, and the application ratio of some industries (such as vegetable cultivation in Japan) and some regions has even reached more than 20%, and the market share of traditional plastic mulch film has gradually declined.

Since 2010, my country has carried out extensive cooperation in the research and development and application of biodegradable plastic films. Japan's Showa Denko Co., Ltd., Germany's BASF, France's Limagrain and other companies have cooperated with China's agricultural scientific research and technology promotion departments, and have carried out biodegradable plastic film demonstrations in Xinjiang in northwest China, Yunnan in southwest my country, and Beijing in north China. The application range of biodegradable mulch film has been further expanded, and it has now covered major crops such as cotton, corn, tobacco, and potatoes.

As a degradable material, its own properties determine that the degradation and application of biodegradable mulch film is a very complex process. The same biodegradable plastic film is applied under different environmental conditions and different crop conditions, and the effect, degradation behavior and degradation time of mulching are quite different. At present, many studies have been carried out on the mechanical matching performance of biodegradable mulch films, the ability to increase heat and moisture and weed control, the time and degree of degradation, and the economic benefits. There is a lack of systematic and comprehensive evaluation of the application of biodegradable plastic film, and the method for the application of biodegradable plastic film in agricultural planting has not been established.

SUMMARY OF THE INVENTION

Based on the above reasons, the present invention provides a method for mulching and planting with biodegradable plastic film. On the basis of the innovatively proposed multi-layer structure biodegradable plastic film, based on the division of plastic film application functions, the selection of plastic film to meet the needs of the environment and crops is proposed. Application technical requirements of biodegradable plastic film.

The technical scheme of the present invention is: a method for planting with biodegradable plastic film, comprising:

(1) Planting test

In the area to be planted, a biodegradable mulch film is preliminarily selected according to the planting needs of the crops to be planted, and a small-area pilot test is carried out. The biodegradable mulch film is a multi-layer biodegradable mulch film;

Before the planting test, collect the information of the planting area, basic information of plastic film, soil physical and chemical properties and crop production information;

In crop planting, the soil temperature under the film and the moisture barrier performance of the film, as well as the field degradation performance of the film are measured, and the agronomic traits, output value and quality of the crops are measured;

(2) Selection of mulch film

Determine the multi-layer biodegradable mulch film required for crop planting in the planting area according to planting test matching;

(3) Crop planting

When the crops in the planting area are officially planted, the matching multi-layer biodegradable plastic film is used to cover the planting.

The optional planting of crops includes the following steps:

S1 soil preparation: remove impurities from the soil and ensure that the soil surface is level;

S2 fertilization: fertilize before mulching, the fertilizer is organic fertilizer, farmyard manure or soil conditioner required for crop planting, and the fertilization time is more than 15 days before mulching;

S3 film: use a matching multi-layer structure biodegradable film for filming;

S4 Landfill: After completing the planting requirements of crop mulching, the multi-layer structure biodegradable mulch is smashed and buried in the soil.

Optionally, in the planting test, the multi-layer structure biodegradable mulch film is initially selected to carry out the trial test in the following ways;

For the mulching film whose main purpose is to increase temperature, choose a transparent multi-layer structure biodegradable mulch;

When the main purpose of mulching is to keep warm and stabilize temperature, choose black multi-layer biodegradable mulch;

When the main purpose of the film is to preserve moisture, choose a transparent or black multi-layer biodegradable mulch;

For the purpose of increasing temperature and moisture, and needing to inhibit the growth of weeds, choose the black multi-layer structure biodegradable mulch.

The optional multi-layer structure biodegradable mulch film includes:

The stacked film is formed by stacking multiple layers of films in sequence, and the film is a biodegradable mulch;

An air layer is formed between adjacent ones of the stacked films.

Optionally, the number of layers of the laminated film is 2 to 4 layers.

Optionally, the number of layers of the laminated film is 2 layers.

Optionally, the thicknesses of the two layers of the stacked films are the same or different

Optionally, the longitudinal edges of adjacent films in the stacked films are connected.

The optional information on the planting area includes soil type, fertility level, rainfall, rainy season time, light, and air temperature.

The optional basic information of the mulch film includes the mulch film width, the mulch film thickness, and the mulch film color.

The beneficial effects of the present invention are: on the basis of the innovatively proposed multi-layer structure biodegradable plastic film, the present invention is based on the division of plastic film application functions, develops plastic film selection that meets the needs of the environment and crops, and proposes application technical requirements for biodegradable plastic films, The mulching film parameters can be optimized to determine the appropriate type of biodegradable mulching film in the crop planting area, which can then promote the good growth of crops.

The multi-layer structure biodegradable mulch film in the present invention has an intermediate air layer. Since air has a low thermal conductivity, the existence of the air layer enables the mulch film to have a better stabilization effect on soil temperature. In agricultural planting, the barrier effect of heat radiating from the soil to the atmosphere can make the soil have a better thermal insulation effect than the one without film or covered with a single layer of film, especially in the stage of crop seed germination and seedling growth, the thermal insulation effect of the soil seems very important. In addition, the heat transferred from sunlight to the soil can also be blocked by the air layer, so that the soil temperature will not be too high, resulting in burning seedlings. Compared with the prior art, the multi-layer biodegradable mulch film has the following advantages: 1. Compared with the traditional mulch film with the same thickness, the multi-layer structure biodegradable mulch film can achieve better soil insulation effect and better soil water retention effect, and can realize the adjustment and combination of different functions. 2. No additional production cost. 3. It has great potential to replace the current common degradable plastic film.

Description of drawings

1 is a schematic structural diagram of one of the multi-layer structure degradable mulch films of the present invention;

2 is a schematic structural diagram of another multi-layer structure degradable mulch film of the present invention;

3 is a schematic structural diagram of a two-layer structure degradable mulch film of the present invention;

Figure 4 shows the relationship between soil temperature and time in Example 5 and Comparative Example 1, where Example 5 is a two-layer film, and Comparative Example 1 is a single-layer film;

Figure 5 shows the relationship between soil water content and time in Example 5 and Comparative Example 1, where Example 5 is a two-layer film, and Comparative Example 1 is a single-layer film;

In the drawings, 1 film, 2 air layer.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementation disclosed below.

The present invention provides a method for planting covered with biodegradable plastic film, comprising:

(1) Planting test

In the area to be planted, a biodegradable mulch film is preliminarily selected according to the planting needs of the crops to be planted, and a small-area pilot test is carried out. The biodegradable mulch film is a multi-layer biodegradable mulch film;

Before the planting test, collect the information of the planting area, basic information of plastic film, soil physical and chemical properties and crop production information;

In crop planting, the soil temperature under the film and the moisture barrier performance of the film, as well as the field degradation performance of the film were measured, and the agronomic traits, output value and quality of the crops were measured.

The following is an example of tobacco cultivation:

1. Basic data collection

Before tobacco planting, the basic information of tobacco fields and plastic film, soil physical and chemical properties, and flue-cured tobacco production information were collected.

1.1 Basic information of smoke field and mulch film

See Table 1 for basic information on smoked fields and mulch films.

Table 1 Basic information of smoke field and plastic film

The mulch film in this table is a multi-layer biodegradable mulch film, and the basic information of the mulch film can also be increased, such as the thickness of each layer. In addition, the basic physical parameters such as tensile load (longitudinal and transverse), nominal strain at break (longitudinal and transverse) and right-angle tear load (longitudinal and transverse) can also be measured before the mulching film is used.

1.2 Soil physical and chemical properties

The soil physicochemical properties are shown in Table 2.

Table 2 Soil physicochemical properties of tobacco fields

1.3 Flue-cured tobacco production information

The production information of the test demonstration flue-cured tobacco is shown in Table 3.

Table 3 Test Demonstration Flue-cured Tobacco Production Information Sheet

1.4 Processing settings

Four-row areas are used for the treatment of the plot, each treatment area is not less than 50m ² , and each treatment is repeated no less than 3 times, and protection rows are required to be set up around the evaluation plot. Demonstration verification that each treatment is not less than 25 acres. Cultivation techniques are managed according to local flue-cured tobacco cultivation techniques, except for the specific requirements for test demonstrations.

2. Indicator measurement

In tobacco planting, the soil temperature under the film and the moisture barrier properties of the film, as well as the field degradation performance of the film were determined, and the agronomic traits, output value and quality of the crops were determined.

2.1 Mechanical properties of plastic film

Carry out the mulching operation according to the conventional mulching method, and evaluate whether the mulching film is broken and stuck under the mulching method, and whether it can meet the requirements of manual or mechanical operation.

2.2 Soil temperature

A low temperature sensor was used to measure the soil temperature under the membrane. Specifically, the soil temperature under the membrane was measured by using a platinum resistance ground temperature sensor (probe, with an accuracy of ± 0.3° C.) supporting a data acquisition system. Three ground temperature probes were installed in each treatment area, and the burial depths were 10 cm, 20 cm and 30 cm, and the data acquisition record was set to record data once every 1 h.

2.3 Moisture barrier properties of plastic film

The test is carried out according to GB/T 1037, and the water vapor transmission rate reflects the change of soil moisture of the participating plastic film.

2.4 Agronomic traits of tobacco

Agronomic indicators such as plant height, stem circumference, maximum leaf length, maximum leaf width and effective leaf number of flue-cured tobacco in each treatment were measured at the tobacco dome stage.

2.5 Output value of cured tobacco leaves

After the tobacco leaves were harvested and cured, the output value indicators such as the yield, output value, average price, high-grade tobacco rate and medium-high-grade tobacco rate of cured tobacco leaves for each treatment were counted.

2.6 Quality of primary flue-cured tobacco leaves

According to the treatment, it is listed on the kang. After the curing, the samples of flue-cured tobacco leaves are collected according to GB/T 19616, and the quality evaluation of the appearance quality, physical properties, chemical composition and sensory evaluation of the tobacco leaves is carried out.

2.7 Field degradation performance of plastic film

2.7.1 Observation of degradation situation

Photographs were used to form a time series table of plastic film degradation, and the number of cracks in the plastic film, the number and width of cracks, the number and size of broken pieces were observed and recorded, and the degradation stage of the plastic film was determined accordingly.

In one example, a fixed sample point was selected for each treatment, and a fixed frame (50cm×50cm) was used to take fixed-point photographs. From mulching to transplanting, take pictures every 10 days; from 0 to 30 days after transplanting, take pictures every 10 days; from 31 days onwards, take pictures every 5 days until the end of the induction period; after that, take pictures every 10 days until the end of the induction period. The film-free period constitutes a time series list of plastic film degradation. After each photo is taken, the photo is marked (film sample number, photo date, degradation status), and the problem is found and remedied in time.

A 1m fixed quadrat was selected for each treatment, and the number of film cracks, the number and width of cracks, and the number and size of broken pieces were observed and recorded each time a photo was taken, and the degradation stage of the film was judged accordingly. as shown in the table below.

Table 4 Observation table of plastic film degradation

Table 5 Determination table of plastic film degradation stages

deal with Induction period (A) Cracking period (B) Great rift (C) Fragmentation period (D) Membrane-free period (E)

2.7.2 Evaluation of Degradation Degree

Investigate the degree of partial degradation of mulch ridge surface and furrow buried soil for each treatment. As a sampling unit for each treatment, starting from mulching, using the plum blossom point method or the diagonal method, the ridge surface of each treatment 50cm × 50cm (longitudinal × transverse), and the buried soil portion of the ridge and furrow 50cm × 5cm ( 3 plastic film samples with the size of vertical × horizontal), number the samples, and bring them back to the room for testing. Collected once every 2 months, till the film-free period or tobacco field tillage.

The film samples were flattened and photographed, the weight of the mulch film was determined by weighing method, and the degradation rate of the mulch film was calculated.

Table 6 Degradation degree of ridge surface

Table 7 Degradation degree of buried soil in furrows

(2) Selection of mulch film

The multi-layer biodegradable mulch film required for crop planting in the planting area is determined according to the planting test match. In the experiments of multiple groups of different mulching films, a group of mulching films with the best test effect was selected.

(3) Crop planting

When the crops in the planting area are officially planted, the matching multi-layer biodegradable plastic film is used to cover the planting.

In one example, the planting of crops includes the steps of:

S1 soil preparation: remove impurities from the soil and ensure that the soil surface is level. Specifically, before mulching, it is necessary to recycle the waste mulch film remaining in the farmland, remove crop residues, large clods, and stones in the soil, and especially do a good job in weed control (serious weeds, conventional polyethylene mulch film also cannot be used) meet the requirements) to ensure that the soil surface is flat and avoid premature damage to the mulch during the laying process.

S2 fertilization: fertilize before mulching. The fertilizer is organic fertilizer, farmyard manure or soil conditioner required for crop planting. The fertilization time should be more than 15 days before mulching to avoid direct contact between mulch and fertilizers with high microbial content. , resulting in premature degradation of the mulch.

S3 Lamination: Biodegradable mulch mulch uses the same mulching method as conventional polyethylene mulch, but it is naturally flattened when mulching, and it is strictly forbidden to forcefully pull it to avoid longitudinal tension. The mulch should be moderately close to the ridge surface, to avoid wind swaying due to too loose laying or thinning of the thickness caused by too tight mulching. In areas with strong wind, it is recommended to cover a small amount of soil on the exposed part of the plastic film every two or three meters.

S4 landfill: After completing the planting requirements of crops, there is no need to remove the film for recycling, and the multi-layer biodegradable plastic film is directly smashed and buried into the soil by using tools or hoes.

Since the biodegradable mulch film will be completely degraded, it does not need to be recycled compared with the ordinary mulch film. It can be directly smashed and buried in the soil with a machine or a hoe. In addition, soil properties and environmental factors are the fundamental factors affecting the degradation of biodegradable plastic films, and there will be differences in the degradation rates of plastic films exposed on the surface and buried in the soil during production. After the end of use, the farmland can be cleaned and turned up in time to ensure that the mulch film is fully buried in the soil and promote its rapid degradation.

In the present invention, soil preparation, fertilization, film mulching and landfilling are general means in the process of using biodegradable plastic film. As for crop sowing or transplanting, it can be selected before fertilization, after fertilization, or after mulching according to the situation.

Please refer to FIG. 1 to FIG. 3, the multi-layer structure biodegradable mulch film in the present invention includes:

The stacked film is formed by stacking multiple layers of films 1 in sequence, and the film 1 is a biodegradable mulch;

The air layer 2 is formed between adjacent films 1 in the stacked films 1 .

The multi-layer structure biodegradable mulch film has an intermediate air layer 2. Since the air has a low thermal conductivity, the existence of the air layer 2 makes the mulch film have a better stabilization effect on soil temperature. In agricultural planting, the barrier effect of heat radiating from the soil to the atmosphere can make the soil have a better thermal insulation effect than the one without film or covered with a single layer of film, especially in the stage of crop seed germination and seedling growth, the thermal insulation effect of the soil seems very important. In addition, the heat transferred from the sunlight to the soil can also be blocked by the air layer 2, so that the soil temperature will not be too high and the seedlings will not be burned.

At the same time, due to the existence of the air layer 2, in agricultural planting, when the film layer far from the soil moves relative to the film layer close to the soil due to changes in the external environment, the film layer close to the soil can be kept as stable as possible, thereby making the film layer close to the soil as stable as possible. The air layer 2 existing between the film 1 close to the soil and the soil is stable, and the applicant has found that the stability of the air layer 2 can make the change of soil temperature controllable.

The multi-layer structure biodegradable mulch film can form multiple air layers 2 between adjacent films 1 . For example, when the laminated film is composed of three layers of films 1, there are two air layers 2, and when the laminated film is composed of four layers of films 1, there are three air layers 2. Preferably, the number of layers of the laminated film is 2-4 layers, and the number of layers can take into account the balance between the production cost and the use effect. More preferably, the number of layers of the laminated film is 2, and its production cost is the same as that of the existing single-layer mulch film, but it has various advantages of the air layer 2 .

In order not to increase the cost of using mulch film per mu, the sum of the thicknesses of the multi-layer films 1 mentioned in the present invention is the same as the thickness of the currently common single-layer film mulch film. In an example, the thickness of the currently commonly used single-layer degradable or fully degradable mulch film is 8-12 microns, and the sum of the thicknesses of each film 1 in the laminated films produced by the present invention is also 8-12 microns.

As a preferred solution, the thickness of each layer of film 1 may be the same or different. Preferably, by adjusting the thickness difference of the two layers of films 1, different refraction powers of the films 1 for light can be achieved, thereby adjusting the influence of light on the temperature and water content of the soil covered by the mulch film.

As a preferred solution, each layer of film 1 has the same color. In one example, the two layers of film 1 are both transparent films. At this time, the barrier of the film to sunlight is relatively small. In addition, due to the combined action of the air layer 2, the temperature of the soil is lower than that of the single-layer transparent film. However, the applicant found that , when there is no sunlight, the soil temperature covered by a single layer of transparent plastic film decreases rapidly, while the soil temperature of the plastic film with double-layer transparent film 1 and air layer 2 decreases slowly, and the temperature is higher than that of the soil covered with a single layer of plastic film. Therefore, compared with the soil covered with a single layer of transparent plastic film, the soil covered with the plastic film of this embodiment has a lower temperature difference, that is to say, the plastic film of the present invention can have a better soil heat preservation effect.

In another example, the two layers of film 1 are both black films. During crop planting, the black film far from the soil absorbs a large amount of heat, and the heat conducted to the intermediate air layer 2 is greatly reduced, while the black film close to the soil is A large amount of heat in the intermediate air layer 2 is absorbed, so that the heat transferred to the soil is greatly reduced, so that the soil temperature covered by the mulch film with two layers of black film is lower than that of the soil covered by the single layer of black film. Due to the effect of the intermediate air layer 2, the soil temperature difference of the mulch film covered with a double layer of black film is lower than that of the mulch film covered with a single layer of black film.

As a preferred solution, the colors of each layer of film 1 are different. In one example, the upper layer of the two-layer film 1 is a black film, and the lower layer is a transparent film. In agricultural planting, the film 1 far from the soil is a black film, and the film 1 close to the soil is a transparent film. On the one hand, the temperature of the soil after covering is lower than that of covering the transparent film or the black film alone. , due to the better thermal insulation effect, the nighttime soil temperature covered with the mulch film in this example is higher than that covered with a single black mulch film, but lower than that covered with a single transparent mulch film due to the temperature difference during the day.

The embodiment of the present invention also provides a method for preparing a multi-layer structure biodegradable mulch film, comprising: stacking the multilayer films 1 together in sequence, and hot pressing to form a stacked film, wherein the film 1 is a biodegradable mulch film; An air layer 2 is formed between adjacent films 1 in the stacked films. Please refer to Fig. 1 and Fig. 2 again, generally speaking, after the multilayer films 1 are stacked, the films 1 can be formed into point joints (fixed by heat-compression fusion at a certain point) or wires at a set position by hot pressing. Bonding (fixed by thermocompression on a line). Usually, the two longitudinal sides of the adjacent films 1 in the stacked films are connected by hot pressing, and different layers of films 1 can be fixed by hot pressing, so that they are affected as little as possible by the environment during use. The hot pressing of the film 1 is a common knowledge of those skilled in the art and will not be described in detail here.

Preferably, the multilayer film 1 has two layers, and the two-layer film 1 can be prepared by blow molding or tape casting. One layer can be prepared by tape casting and the other layer by blow molding. Both layers may be prepared by tape casting, or both layers may be prepared by blow molding. Since the film 1 prepared by tape casting has relatively high mechanical strength, the compounding of the two forming methods enables the mulch film of the present invention to have better barrier properties and better mechanical properties.

In one example, after two films 1 of the same size are prepared by tape casting, the two films 1 are stacked together, and then the two films 1 are hot-pressed along the longitudinal sides (ie, the long sides) of the stacked films to make the two films 1 Fixed connection. In another example, after two films 1 of the same size are obtained by tape casting, the two films 1 are stacked together, and then the two films 1 are fixedly connected by heat pressing at different points on the stacked films.

After the multi-layer film 1 is fixed by hot pressing, since the films 1 are connected by two longitudinal sides or points, there will be a gap between adjacent films 1, that is, the air layer 2. In addition, during the film-covering planting process, due to shaking or transplanting and punching, air will enter between the adjacent films 1 to form an air layer 2 of a certain thickness.

Referring to FIG. 3 again, the embodiment of the present invention further provides a method for preparing a multi-layer structure biodegradable mulch film, comprising: directly winding the film 1 obtained by blow molding without slitting to obtain a stacked film, An air layer 2 is formed in the middle of the stacked films, and the film 1 is a degradable mulch film.

During the film blowing process, when the unslit cylindrical film 1 is rolled, an intermediate air layer 2 with a certain thickness will be formed in the middle. In addition, during the planting process of the plastic film, an intermediate air layer 2 with a certain thickness will also be formed due to shaking or transplanting and punching.

The biodegradable mulch film in the embodiment of the present invention is a mulch film well known to those skilled in the art, and can be prepared by any one of blow molding, tape casting, compression molding, and coating molding. The degradable mulch film in the present invention may be a mulch film prepared from a fully degradable material or a mulch film prepared from a degradable material.

The multi-layer structure biodegradable mulch film of the present invention has better soil moisture retention effect than the mulch film with a single-layer film obtained by the same material and preparation process. The existence of the double-layer film (the upper film 1 and the lower film 1) makes the moisture have two different paths in the process of penetrating the mulch, and the existence of the air layer 2 makes the moisture permeation have three different paths, which is extremely It greatly increases the difficulty of water penetration and improves the water retention effect of the soil. In addition, the good water retention effect can make the film near the soil layer have more water droplets. The water droplets can generate heat under sunlight, and when the water droplets fall, they can scald the weeds. Therefore, the applicant unexpectedly found that the mulch film of the present invention It can further inhibit the growth of weeds, and further, for the fully degradable plastic film, this effect can also be achieved when the water vapor barrier rate of the film itself is low. At the same time, for a film with high transparency, the use of the mulch film of the present invention can also directly inhibit the growth of weeds.

It should be pointed out that the multi-layer biodegradable mulch film of the present invention has better temperature regulation effect than the mulch film with a single-layer film obtained from the same material and preparation process, and the premise of this effect is the thickness of the mulch film involved in the present invention. The sum is the same thickness as the comparative mulch made from a single layer film.

Specifically, during the planting test, the multi-layer structure biodegradable mulch film was initially selected for mulching in the following manner:

For the mulching whose main purpose is to increase temperature, choose a transparent multi-layer biodegradable mulch. Compared with the soil covered with a single layer of transparent biodegradable mulch, the soil covered with multi-layer transparent biodegradable mulch has a lower temperature difference.

When the main purpose of mulching is to keep warm and stabilize temperature, choose a black multi-layer structure biodegradable mulch, and the soil temperature covered by the multi-layer black biodegradable mulch is lower than that of the single-layer black biodegradable mulch. At the same time, due to the effect of the intermediate air layer 2, the temperature difference of soil temperature covered with multi-layer black biodegradable plastic film is lower than that covered with single layer of black biodegradable plastic film. At the same time, a layer of film 1 away from the soil can be used as a black biodegradable film, and a layer of film 1 close to the soil can be used as a transparent biodegradable film. Or the temperature of the biodegradable black mulch film is low. On the other hand, due to the better thermal insulation effect, the nighttime soil temperature covered with this type of mulch film is higher than that of the biodegradable black mulch film alone. However, due to the temperature difference during the day, Lower temperature than covering biodegradable clear mulch alone.

When the main purpose of mulching is to preserve moisture, such as areas that are relatively arid or where crops require a lot of water, choose a transparent or black multi-layer biodegradable mulch. Because of the multi-layered biodegradable plastic film and the existence of the air layer 2, the path of water permeating through the plastic film is changed, which greatly increases the difficulty of water permeation and improves the water retention effect of the soil.

For the purpose of increasing temperature and moisture, and needing to inhibit the growth of weeds, choose the black multi-layer structure biodegradable mulch.

In order to further understand the present invention, the multi-layer structure biodegradable mulch film provided in the present invention is described below with reference to the examples, and the protection scope of the present invention is not limited by the following examples.

90 parts of PBAT, 5 parts of PLA, 0.5 parts of ADR, and 4.5 parts of calcium carbonate were extruded and granulated through a twin-screw extruder at 170 ° C to prepare particle A, and particle A was prepared by blow molding to prepare a 3-micron-thick full biodegradable mulch film , directly rewinding without slitting to obtain multi-layer fully biodegradable mulch film 1; 3-micron thick fully biodegradable mulch film is prepared from particle A by blow molding, slitting and rewinding to obtain mulch film 1; particle A is blown through molding A 6-micron-thick fully biodegradable mulch film is prepared by molding, slitting and winding to obtain mulch 2; particles A are prepared by tape casting to prepare a 3-micron-thick fully biodegradable mulch, and rolled to obtain mulch 3.

70 parts of PBAT, 10 parts of PLA, 10 parts of calcium carbonate, 0.8 parts of ADR, 9 parts of montmorillonite, and 0.2 parts of talc were extruded and granulated by a twin-screw extruder at 170 ° C to prepare particle B, and particle B was passed through Blow molding to prepare a 3-micron-thick fully biodegradable mulch film, which is directly wound without slitting to obtain a multi-layered fully biodegradable mulch film 2; the particle B is blown to prepare a 3-micron-thick fully biodegradable mulch film, which is slit and wound , to obtain mulch 4; the particles B were blow-molded to prepare a 6-micron-thick fully biodegradable mulch, slit and rolled to obtain mulch 5; 5-micron-thick fully biodegradable mulch was prepared from particles B by blow molding, slit and rolled , to obtain a mulch 6; the particles B are prepared by tape casting to prepare a 3-micron-thick fully biodegradable mulch, and rolled to obtain a mulch 7.

85 parts of PBAT, 5 parts of PLA, 0.5 parts of ADR, 4.5 parts of calcium carbonate, and 5 parts of carbon black masterbatch were extruded and pelletized through a twin-screw extruder at 170° C. to prepare particle C, which was prepared by blow molding to prepare 3 The micron-thick fully biodegradable mulch film was directly wound without slitting to obtain a multi-layer structure fully biodegradable mulch 3; the particle C was blown to prepare a 3-micron thick fully biodegradable mulch film, slitted and rolled to obtain a mulch 8; The particles C were blow-molded to prepare a 6-micron-thick fully biodegradable mulch film, which was slit and rolled to obtain a mulch 9;

99 parts of LDPE and 1 part of calcium carbonate were extruded and granulated through a twin-screw extruder at 160° C. to prepare particle D, and particle D was blown to prepare a 3-micron-thick mulch film, which was directly wound without slitting to obtain more Fully biodegradable mulch film 4 with layer structure; 6-micron-thick mulch film is prepared by blow molding the particles D, slitting and winding to obtain mulch film 11 .

The two mulching films 1 are superimposed to obtain a multi-layer structure fully biodegradable mulching film 5 . The multi-layer structure fully biodegradable mulch film 6 is obtained by superimposing the mulch film 1 and the mulch film 3 . The multi-layer structure fully biodegradable mulch film 7 is obtained by superimposing the mulch film 4 and the mulch film 6 . The multi-layer structure fully biodegradable mulch film 8 is obtained by superimposing the mulch film 4 and the mulch film 7 . The multi-layer structure fully biodegradable mulch 9 is obtained by superimposing the mulch 1 and the mulch 4 . The multi-layer structure fully biodegradable mulch film 10 is obtained by superimposing the mulch film 1 and the mulch film 8 . The multi-layer structure fully biodegradable mulch film 1 is embossed to obtain the multi-layer structure fully biodegradable mulch film 11 . The multi-layer structure fully biodegradable mulch film 12 is obtained by superimposing the mulch film 10 and the mulch film 8 .

The multi-layer fully biodegradable plastic films 1 to 12 are taken as Examples 1 to 12, respectively, and the plastic films 2, 5, 9 and 11 are taken as Comparative Examples 1 to 4, respectively, and a plot with the same soil conditions is divided into areas The same 17 small plots were used, and the 16 small plots were covered with the plastic films in Examples 1 to 12 and Comparative Examples 1 to 4 with the same area, and the soil without plastic film was set as Comparative Example 5.

The temperature and water content of the soil at a depth of 15cm were tested by using Luge L99-TWS-1, which was tested every 10 minutes and collected automatically. The water content is the average value of the 24-hour test data, the highest temperature is the highest soil temperature of the day, and the lowest temperature is the lowest temperature within 24 hours, calculated from the highest temperature point.

The results refer to Figures 4, 5, and Tables 8 to 10.

Table 8 Effect of multi-layer structure biodegradable plastic film on warming and moisture retention

Table 9 Effect of multi-layer structure biodegradable plastic film on warming and moisture retention

Table 10 Test on the effect of heat preservation and moisture retention of multi-layer structure biodegradable plastic film (comparative example)

The above experimental data show that the multi-layer biodegradable mulch film of the present invention can achieve better soil heat preservation effect and better soil water retention effect than the traditional mulch film with the same thickness.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (10)

1. a method for planting with biodegradable plastic film, is characterized in that, comprises: (1) Planting test In the area to be planted, a biodegradable mulch film is preliminarily selected according to the planting needs of the crops to be planted, and a small-area pilot test is carried out. The biodegradable mulch film is a multi-layer biodegradable mulch film; Before the planting test, collect the information of the planting area, basic information of plastic film, soil physical and chemical properties and crop production information; In crop planting, the soil temperature under the film and the moisture barrier performance of the film, as well as the field degradation performance of the film are measured, and the agronomic traits, output value and quality of the crops are measured; (2) Selection of mulch film Determine the multi-layer biodegradable mulch film required for crop planting in the planting area according to planting test matching; (3) Crop planting When the crops in the planting area are officially planted, the matching multi-layer biodegradable plastic film is used to cover the planting. 2. biodegradable plastic film covering planting method according to claim 1, is characterized in that, described crop planting comprises the following steps: S1 soil preparation: remove impurities from the soil and ensure that the soil surface is level; S2 fertilization: fertilize before mulching, the fertilizer is organic fertilizer, farmyard manure or soil conditioner required for crop planting, and the fertilization time is more than 15 days before mulching; S3 film: use a matching multi-layer structure biodegradable film for filming; S4 Landfill: After completing the planting requirements of crop mulching, the multi-layer structure biodegradable mulch is smashed and buried in the soil. 3. biodegradable mulch film covering planting method according to claim 1, is characterized in that, in planting test, preliminarily selects multi-layer structure biodegradable mulch film to carry out trial test in the following manner; For the mulching film whose main purpose is to increase temperature, choose a transparent multi-layer structure biodegradable mulch; When the main purpose of mulching is to keep warm and stabilize temperature, choose black multi-layer biodegradable mulch; When the main purpose of the film is to preserve moisture, choose a transparent or black multi-layer biodegradable mulch; For the purpose of increasing temperature and moisture, and needing to inhibit the growth of weeds, choose the black multi-layer structure biodegradable mulch. 4. The method for covering planting with biodegradable plastic film according to claim 1, wherein the multi-layer structure biodegradable plastic film comprises: The stacked film is formed by stacking multiple layers of films (1) in sequence, and the film (1) is a biodegradable mulch; An air layer (2) is formed between adjacent films (1) in said stacked films. 5 . The method for planting covered with biodegradable plastic film according to claim 4 , wherein the number of layers of the stacked film is 2-4 layers. 6 . 6 . The method for covering planting with biodegradable plastic film according to claim 5 , wherein the number of layers of the stacked films is 2. 7 . 7 . The method for planting covered with biodegradable plastic film according to claim 6 , wherein the thicknesses of the two layers of films ( 1 ) in the stacked films are the same or different. 8 . 8. The method for planting with biodegradable plastic film covering according to claim 4, characterized in that the two adjacent films (1) in the stacked films are connected on both sides in the longitudinal direction. 9 . The method for planting with biodegradable plastic film mulching according to claim 1 , wherein the information on the planting area includes soil type, fertility level, rainfall, rainy season time, light, and air temperature. 10 . 10 . The method for planting with biodegradable mulch film according to claim 1 , wherein the basic information of the mulch film includes the width of the mulch film, the thickness of the mulch film, and the color of the mulch film. 11 .

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