JPH0445497Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to an agricultural mulch film that covers fields, ridges, etc. and adjusts the temperature in the soil to create an optimal environment for the growth of plant roots. [Prior Art] Multi-films made of various thermoplastic resins are currently used in Japan. The film is mainly polyethylene film, thickness 7~40μ, width 80~
A length of around 180cm is often used. The effects of mulch cultivation include mulching film on the ground surface to retain soil moisture, maintain soil swelling and softness, prevent fertilizer runoff, suppress disease damage, and increase and control soil temperature, promoting early growth and increasing initial yield. The goal is to increase production, stabilize production, and increase yields. Figure 1 shows an outline of film mulch cultivation. In Figure 1, 1 is a ridge, 2 is a multi-film,
3 is a plant. 4 is soil that presses both sides of the mulch film 2. When looking at the current multi-films from the perspective of soil temperature control, their purpose is broad and can be classified into the following two types. The first type is a film intended to raise soil temperature, and is often used when cultivation is started at relatively low temperatures and in cold regions at high latitudes. The film used is mainly transparent polyethylene film, but in addition to this, polyethylene film colored green or black or the shoulder part of the ridge, which is made up of a transparent part and a black part, is used to suppress the growth of weeds, although the soil temperature is slightly lowered. Two-color mulch films that suppress weed growth are also commercially available and in use. The second type is a film that aims to suppress the rise in soil temperature, and is often used when cultivation is started during relatively high temperatures or for low-temperature crops. A variety of light-reflective, primarily polyethylene-based films are commercially available that are designed to reflect sunlight and reduce solar energy from entering the ground. Typical films are abbreviated below. Aluminum powder kneaded polyethylene film (silver multi-film) Contains approximately 2% by weight or more of aluminum powder, thickness 20
Many are ~30μ. Aluminum vapor-deposited polyethylene film (mirror multi-film) Aluminum is vacuum-deposited to a thickness of several hundred Å on the surface of a polyethylene film approximately 20μ thick. It's expensive. Aluminum foil laminated polyethylene film (aluminum multi-film) A film made by laminating aluminum foil and polyethylene film with excellent light reflectivity. It's expensive. A laminated polyethylene film with a thickness of 20 to 30 μm (black and white double multi-film) consisting of two layers: a white film layer kneaded with titanium oxide powder and a black layer kneaded with carbon black powder. Table 1 shows the maximum soil temperature during the day at a depth of 5 cm underground for representative films of the type that are relatively widely used at present, and the characteristics of each film are clear. The film was laid on a ridge with a ridge width of 60 cm and a length of 5 m, and the soil temperature was measured at the center of the ridge using a thermocouple. The test was conducted at the applicant's Chiba factory in two periods in March and August 1981.

[Problem that the invention attempts to solve]

In this way, various types of mulch films are used for various crops by taking advantage of their characteristics, but if you use only one type of mulch film, such as the first type of transparent mulch film, for the entire cultivation period, the crops will be mulched. It is often observed that inconveniences occur in cultivation. For example, in the Kanto region, mulch is often used during the low temperature period from March to April, and in this case transparent mulch film is often used. This aims to raise the initial soil temperature and promote early growth, including early germination, stable growth, and early establishment. However, in the May-June period, with the rapid rise in temperature,
There are many days when the ground temperature reaches high ground temperatures of 35 to 45 degrees Celsius. You want to raise the soil temperature during the initial growing period, but you want to lower the soil temperature after that, so in such cases, using only transparent mulch film is not appropriate because the soil temperature will rise too much from May to June onwards. . During this period, the so-called second type of reflective multifilm is better. As an example of this, when vines are attracted to a high position using supports, such as cucumbers, the ridges are constantly exposed to strong sunlight and exhibit high ground temperatures, which accelerates root aging.
Phenomena such as frequent disease outbreaks and shortened lifespans appear. In addition, in the case of crops such as potatoes and canes, which accumulate a large amount of starch in their tubers and tuberous roots, high ground temperatures alone will cause respiratory exhaustion and inhibit accumulation. Contrary to this example, when sowing and planting around the end of July to August, from the point of view of early germination and stabilization of growth,
The second type of reflective multi-film, which can suppress the rise in soil temperature, is often used. However, in this case as well, once we enter the low-temperature period from October onwards, we want to raise the soil temperature, so the first type of transparent multi-film is better here. As an example of this, in the case of tomatoes cultivated under controlled greenhouse conditions, the economical significance of non-heating cultivation is high if the harvest can be completed by the end of the year. In order to achieve this purpose, it is desirable to promote growth by increasing soil temperature from the middle stage onwards. As described above, there are many cases in which the requirements for soil temperature control by mulch are opposite in the early, middle, and later stages of cultivation, and it is difficult to meet these requirements with the various types of mulch films that are currently available. [Means for solving the problem] Therefore, in 1977, a multi-film was developed in which a light-reflecting surface and a heat-absorbing surface are shared on the same surface.
−51241, Utility Model No. 51-102534, Utility Model Kai No. 56-
It was proposed in Publication No. 1484, etc. For example, a two-color multi-film of black/silver film with aluminum vapor deposition or aluminum foil pasted in strips on the surface of black polyethylene film, a strip of black film and black and white double mulch arranged alternately, and a strip of black film and white film. They are arranged alternately. The black film part absorbs solar heat and raises the soil temperature, and the silver or white film part reflects solar heat, promoting the growth of seedlings and ripening of fruits, and also repelling flying winged aphids. Since it has both effects, it has the advantage of improving yield rate or sugar content of fruit compared to cultivation using light-blocking mulch films such as black film, black and white double mulch, silver mulch, mirror mulch alone. have However, these multi-films have some room for improvement in terms of increasing soil temperature. [Means for solving the problem] The present inventors conducted various studies based on the idea that if the soil temperature could be more effectively raised, the plant growth effect could be expected to be more effective. We discovered that a combination of a certain film that has the effect of raising soil temperature and a light-reflecting film that suppresses the rise in soil temperature is a good combination, and arrived at the present invention. That is, the present invention uses a first soil temperature increasing type film A selected from a transparent resin film and a green resin film, an aluminum powder kneaded resin film, an aluminum vapor deposited resin film, an aluminum foil laminated polyethylene film, and a titanium oxide powder. A second geothermal temperature suppressing type film B having light reflectivity selected from a laminated film consisting of a white film layer kneaded in and a black film kneaded with carbon black powder is used, and the width of film A is l _A and the width of film B is When l _B is the width, l _A is 10 cm or more, width l _B is 10 cm or more, and l _A
At least one of the above and _lB provides an agricultural mulch film in which the films are combined in the longitudinal direction with a width of 20 cm or more. [Operation] The multi-film of the present invention has a first soil temperature increasing type film A and a second soil temperature suppressing type film B.
Therefore, in the ground that covers it, there are parts with high and low temperatures, so even during the low temperature period from March to April or the high temperature period after May to June, the temperature of either one of the underground areas is high. One part is at the appropriate temperature for early plant growth, and the other is at the appropriate temperature for late growth, making it effective as it can be used in both low-temperature and high-temperature periods, and eliminating the need to replace conventional single-color mulch films, saving labor. and materials can be saved. In addition, a light blocking film type film A,
The effect of increasing soil temperature is superior to that of a film in which light-reflective films B are arranged alternately in strips. [Example] The present invention will be explained in more detail below. The basic structure of the agricultural mulch film of the present invention is as shown in FIGS. 2a, b, and c. As shown in Figure 2a, the center of the first soil temperature increase type film A selected from transparent resin film and green resin film, or one half of film A as shown in Figure 2b, or as shown in Figure 2c. Silver multi-film, mirror multi-film, aluminum multi-film, black and white double multi-film (white side is top, black side is bottom), which have light-blocking properties and light-reflectivity on both sides of film A, as shown in Figure 7. A second soil temperature suppressing type film B made of a light-reflective film selected from the silver-black double multi-film with aluminum foil laminated or aluminum vapor-deposited on the black film shown in , in the longitudinal direction of the film. It is. Incidentally, the position of the central reflective film B in the type a film 5 shown in FIG. Further, the arrangement order may be changed as shown in FIG. 2c. The key to the design was the combination ratio of both types of film. That is, in the mold shown in Figure 2a, if the widths of both types of films A and B are l _A and l _B , then during mulching, the first type of film A has a width of about 10 to 10 mm on both sides.
Since it will be pressed down by soil 4 by about 15 cm and go into the soil, take this into account and set the width l _A to 20 cm or more. Width l _B
shall be 10cm or more. In addition _, in the mold shown in Fig. 2b, the widths l _A and l _B are set to be at least 20 cm for both sides, taking this into account since they go into the soil by approximately ₁₀ to 15 cm on both sides. Furthermore, in the mold shown in Figure 2 c, the width l _A is 10 cm or more, and the width
l _B should be at least 20 cm, taking into account the length that will go into the soil, about 10 to 15 cm. In the present invention, the position of the soil temperature increasing film A may be shifted to the left or right within a range that satisfies the requirements. In general, the boundary line between films A and B may be straight, but as long as it does not interfere with the characteristics of both films A and B, it may be meandering (Fig. 6a) or zigzag (Fig. 6b).
etc. may be used. Furthermore, it may be a thin slit-like cut pattern (for example, about 2 to 4 cm wide) as shown in FIGS. 6c and 6d. In addition, with the film of this invention, both sides are immersed in the soil for about 10 to 30 minutes to hold the film against the soil during mulching.
The 15cm portion is buried and is completely unrelated to soil temperature control. Therefore, if the film portions on the ridges substantially meet the conditions of the present invention, both side portions, that is, approximately 10 to 15 cm on both sides.
The portion may be of either type A or B. The most common resin raw material for multi-film is polyethylene resin, but various thermoplastic resins such as polyvinyl chloride, polyester, and nylon can also be used. These may be used alone or in an appropriate blend of two or more. As additives, commonly used stabilizers, antioxidants, plasticizers, lubricants, fillers, etc. may be added as appropriate. The method for producing the film of the present invention includes the above films A,
Any suitable method that can be considered at present depending on the combination of B may be used. For example, two-color extrusion molding method (inflation method, transparent and silver, transparent and black and white, etc.)
Various methods can be applied, such as the T-die method), a vapor deposition method such as transparent film hair niminium vapor deposition, and a method in which films A and B are separately produced and bonded together by heat sealing or the like in separate steps. The thickness of the film may be determined within a range that satisfies the strength, cost, etc. of the multi-film, and may be in the range of about 5 to 30 μm. In addition, the multi-film has small holes (approximately 5 mm in diameter or less) and cuts (approximately 40 mm or less in width) in the light-reflecting film part of film B to lower the soil temperature due to latent heat of evaporation.
etc. may be provided as appropriate. Next, a method of using the film according to the present invention will be explained. In general, the optimal temperature for plant roots is between 20 and 30 degrees Celsius; if the temperature rises too much, oxygen in the soil decreases, and at 35 degrees Celsius it becomes half of what it was at 15 degrees Celsius, inhibiting root activity. In high humidity, the same damage as when flooded occurs, namely root uprooting, yellowing of leaves, yellowing, increased root respiration, exhaustion of respiration, and poor growth. In addition, raising the temperature of the soil in the early stages of plant growth and creating cool areas underground in the middle stage will effectively store assimilated products. Therefore, plants may be sown or planted in each film A or B portion according to the cultivation period. For example, in the case of suppressed cultivation of high-temperature crops (tomatoes, cucumbers, peppers, eggplants, etc.), seedlings are planted in the high-temperature period of mid-summer and harvested from late autumn to early winter, and in the case of low-temperature crops that are sown in the summer and are harvested in the winter. It is preferable to plant the seeds in portions B of the films 5 and 6 shown in FIGS. 2a and 2b. Examples of such low-temperature crops include soybeans (edamame), radish, Chinese cabbage, lettuce, spinach, carrots, cabbage, and jaggery. On the other hand, crops that are sown in spring and harvested in summer, such as sweet potatoes, taro, corn (sweet corn), watermelons, melons, cucumbers, eggplants, and tomatoes, have a second season.
It is preferable to plant the seeds in the A section of the film 6 and film 7 shown in FIGS. b and c. Films 5, 6, and 7 of the present invention shown in FIGS. 2a, b, and c having the following widths l _A and l _B were manufactured. However, the total width of the film is 120cm.

[Table] Film 5 shown in Figure 2 a, b and c above,
Width l _A of film A or film B in 6 and 7
The relationship between _B and soil temperature is shown in Figures 3, 4, and 5, respectively. Example 1 FIG. 3 shows a film 5 of the type shown in FIG. 2 a,
This figure shows the change in maximum soil temperature during the day at a depth of 5 cm underground at the center of film B when the width l _B of reflective film B at the center is varied. Here, a transparent film N was used as the film A, and a black and white double film WB was used as the film B. Film 5 is a polyethylene film. The ridge is 1m wide and 5m long, and measurements were taken in August 1959. Comparative Example 1 FIG. 4 shows a film 6 of the type shown in FIG. 2 b,
Changes in the maximum soil temperature during the day at a depth of 5 cm underground at the center of film B (excluding the center of the ridge surface, i.e., the soil part) when the width l _B of the reflective film part B on the side is changed. show. Here, film A is black film B, and film B is silver film S.
combined. Film 6 is a polyethylene film. The ridge is 1m wide and 5m long, and was measured in August 1959. Example 2 FIG. 5 shows a film 7 of the type shown in FIG. 2 c,
This figure shows the change in maximum soil temperature during the day at a depth of 5 cm underground at the center of film A when the width l _A of film A is changed. Here, the film A is a transparent film N, and the film B is a black and white double film WB. Film 7 is a polyethylene film. The width of the ridge is 1m and the length is 5m, measured in March 1959. The portion of the film buried in the soil on both sides was approximately 10 cm. As is clear from the experimental results shown in Figures 3 and 5 above, in order for Film A and Film B on the ridge surface to fully exhibit their original characteristics, in order for Film A to fully exhibit its original characteristics, it is necessary to In B, in order to completely suppress soil temperature, each type of film A, B should be used on the ridge surface.
It has been found that the width of B needs to be at least 10 cm or more, preferably 20 cm or more. In addition, the soil temperature increasing film A is a transparent film N with high light transmittance (Examples 1 and 2), and the soil temperature increasing film A is a light blocking black film B (Comparative Example 1). (In August 1959, in Example 1, the difference in maximum soil temperature between Films A and B was approximately 7.7°C.
In Comparative Example 1, the difference is about 4°C). Example 4 A multi-film with the structure shown in Figure 2a (total width 95mm)
cm, thickness 20μ), sweet potatoes (sweet potato variety: Beniazuma) are cultivated in mulch using a mulch film with three strips shown in Table 3, transparent polyethylene film N, black polyethylene film B, or black and white double mulch film. (May 1985
Planting took place on October 25th, and harvesting took place on October 30th, 1985. Table 3 shows the yields of the high quality (high quality) and low quality (below average quality) harvested sweet potatoes. Example 5 A multi-film with the structure shown in Figure 2a (full width
135cm, thickness 20μ), mulch cultivation (1986 Planting was carried out on August 12, 1985, and harvesting was carried out from September 25, 1985 to November 10, 1985. Table 4 shows the yield of the harvested cucumbers and the yield rate of the top products. Example 6 A multi-film with the structure shown in Fig. 2b (full width
180cm, thickness 20μ), watermelon (variety: Kansen) was cultivated in mulch (March 1985) using a mulch film with two strips as shown in Table 5, transparent polyethylene film N, black polyethylene film B, or black and white double mulch film. Planting was carried out on June 4th, 1985, and harvesting was carried out on June 29th, 1985). Table 5 shows the sugar content of the harvested watermelons.

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[Effect of idea]

As described above, according to the present invention, it is possible to create an optimal environment for the growth of plant roots by regulating the temperature in the soil, and to effectively cultivate plants.

[Brief explanation of the drawing]

FIG. 1a is a perspective view showing a state in which the agricultural mulch film according to the present invention is applied, and FIG. 1b is a sectional view thereof.
Figures 2a, b, and c are explanatory diagrams of three embodiments of the present invention, and Figures 3 and 5 respectively show the relationship between the film width and the maximum soil temperature during the day for the multi-film embodiments of the present invention. Figure 4 is a graph showing the relationship between the film width of a conventional multi-film and the maximum soil temperature during the day. Figures 6 a, b, c, and d are plan views of still another embodiment of the present invention. The figure is a sectional view of an embodiment of soil temperature suppressing type film B. A...Soil temperature increase type film, B...Soil temperature suppression type film.

Claims (1)

[Scope of utility model registration request] A first soil temperature increasing type film A selected from a transparent resin film and a green resin film, a resin film kneaded with aluminum powder, an aluminum vapor-deposited resin film, an aluminum foil laminated polyethylene film, and a white film layer kneaded with titanium oxide powder. A second soil temperature suppressing type film B having light reflectivity selected from a laminated film of a black film kneaded with carbon black powder and carbon black powder was added.
l _A , and when the width of film B is l _B , the width l _A is 10 cm
As described above, the agricultural mulch film has a width l _B of 10 cm or more, and at least one of l _A or l _B has a width of 20 cm or more and is combined in the longitudinal direction of the film.