JPS6240966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a plastic sheet having a large number of convex protrusions forming independent air chambers and having a large number of openings in locations other than the convex protrusions. (hereinafter also referred to as a protrusion sheet with openings) and a porous sheet having capillary-like micropores inside are related to a special hotbed used as a hotbed for raising rice seedlings.

In recent years, in order to save labor in farming, it has become popular nationwide for farmers to use rice transplanters to transplant rice. It is becoming important to grow seedlings with good reproducibility in response to climate changes.

Normally, the rice seedlings are raised in a hotbed greenhouse, with appropriate nourishing soil placed in a seedling box with an opening in the bottom and a bottom area suitable for the rice transplanter, and the seeds are sown in the nourishing soil. Seedling boxes were placed directly on the ground surface of the hotbed, the temperature inside the greenhouse was adjusted, and water was sprinkled on the seedling box as needed to germinate and raise the seedlings.

In raising the rice seedlings mentioned above, there are various steps such as adjusting the water content (degree of humidity) and oxygen content of the nutrient soil in the seedling box, irradiating the rice seedlings with sunlight, and adjusting the temperature inside the greenhouse. These are important, and unless they are carried out in harmony, it will not be possible to transplant rice properly using a rice transplanter, and it will not be possible to obtain rice seedlings with well-balanced leaves, stems, and roots that will grow robustly after rice transplantation.

By the way, in the conventional rice seedling raising process described above, the temperature of the ground in the hotbed that the seedling box is in contact with decreases significantly due to heat conduction between the ground inside and outside the greenhouse as the temperature of the ground outside the greenhouse decreases. Therefore, heat is taken away from the area around the seedling nursery box, and the rice seedlings in the nursery box do not grow uniformly or do not grow sufficiently in a short period of time. This often results in the rice transplanter not being able to plant the rice, or the rice seedlings falling over or withering after planting. The above is especially noticeable in cold regions.
Even in warm regions, it was noticeable in regions where daytime and nighttime temperature changes were severe.

Therefore, it is being proposed that a heat insulating sheet be placed between the bottom of the seedling growing box in the hotbed house and the surface of the ground in the hotbed. The conditions necessary for raising seedlings were out of harmony, and rice seedlings were not grown in an even manner. Particularly problematic was the deterioration of drainage, water retention, and air permeability of the hotbed caused by the heat insulating sheet, which inhibited the root growth of rice seedlings.

The inventors have discovered that it is possible to raise rice seedlings that are not adversely affected by the drop in temperature of the ground in the hotbed, and that do not cause deterioration of drainage, water retention, air permeability, etc. under the bottom of the nursery box. As a result of examining various types of hotbeds for seedlings, we arrived at the hotbed for raising seedlings of the present invention.

That is, the present invention provides a hotbed greenhouse having a large number of convex protrusions forming independent air chambers between the bottom of a rice seedling growing box and the surface of the ground of the hotbed. A plastic sheet having a large number of holes in places other than the convex projections (protrusion sheet with holes) and a porous sheet having capillary-like micropores inside are stacked with the porous sheet as an upper layer. This relates to a hotbed for growing seedlings that is placed along the ground surface.

If rice seedlings are raised in the hotbed of this invention, even in cold regions or areas with large temperature differences between day and night, the excellent heat insulation properties of the protruding sheet with perforations placed on the ground surface of the hotbed will allow , since the temperature near the seedling box in the hotbed will not drop significantly.
The rice seedlings grow fast enough.

In this invention, a porous sheet having capillary-like micropores inside is arranged between the protruding sheet with openings and the bottom of the seedling box, so water is sprinkled on the seedling box and the seedling box is raised. Part of the water that is drained from the bottom or sprinkled outside the seedling box can be retained, so the bottom of the seedling box does not dry out and inhibit root growth.

In addition, in this invention, since both the perforated projection sheet and the porous sheet have water permeability, excess water of the water sprinkled on the seedling nursery box can be drained underground. This prevents excess water from remaining under the bottom of the seedling box and impeding ventilation.

The hotbed for raising seedlings of the present invention is prepared by preparing the ground appropriately from the above-mentioned projection sheet with openings, porous sheet, and seedling-raising box (including nourishing soil), and sequentially placing each of the above-mentioned materials on the ground. It can be easily manufactured by doing this, and its maintenance is also easy.

Hereinafter, the hotbed for raising seedlings of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an example of a situation in which a hotbed for raising seedlings of the present invention is formed in a hotbed house and rice seedlings are raised, and FIG. FIG. 2 is an enlarged cross-sectional view of an example of a hot bed.

FIG. 3 is a perspective view showing an example of a protrusion sheet with apertures, and FIG. 4 is a sectional view of the protrusion sheet. FIG. 5 is a sectional view showing another example of the protrusion sheet with openings.

As shown in FIGS. 1 and 2, this invention provides a projection with an opening between the bottom surface of a seedling box 2 for rice seedlings 4 and the surface of the ground 5 of the hotbed inside a hotbed house 1. The sheet 6 and the porous sheet 3 are stacked on top of each other with the porous sheet as an upper layer, and the sheet 6 and the porous sheet 3 are placed on top of each other and are arranged along the ground surface. This relates to a hotbed for growing seedlings.

As shown in FIGS. 3 to 5, the perforated protrusion sheet 6 according to the present invention is provided with a large number of convex protrusions 8 arranged to form independently sealed air chambers 7. and the convex protrusion 8
This is a plastic sheet with a large number of holes 9 provided in locations other than the .

Such a protrusion sheet 6 with apertures is, for example,
A plastic sheet having a large number of convex protrusions forming independent air chambers (hereinafter referred to as Any material may be used as long as it is manufactured by providing a large number of drainage and ventilation holes in a protrusion sheet (sometimes simply referred to as a protrusion sheet).

To describe in detail a specific example of the method for manufacturing the projection sheet, for example, a first sheet of raw material film that has been heated and softened is wound around an embossing roll having a large number of recesses, and the raw material film is brought into close contact within the recesses. A convex protrusion is formed on the first raw material film, and then a second heated and softened raw material film is wrapped around the first film on which the protrusion is formed, and the protrusion on the first film is formed. A preferred method is to manufacture the protrusion sheet by thermally adhering a second raw film (back film) to the other surface.

Any method may be used to form a large number of perforations in the protrusion sheet produced by the above method. For example, in the production of the protrusion sheet described above, convex When a second raw material film is overlaid and thermally bonded to the first film on which the protrusions have been formed, a large number of holes are regularly punched in locations other than the protrusions almost simultaneously with the adhesion. This method is preferred, and by this method, the protrusion sheet with perforations shown in FIGS. 3 and 4 can be obtained.

In this invention, the protrusion sheet with apertures includes:
A third raw material film 10 (preferably a film having a large number of perforations 12) is added to the perforated protrusion sheet formed from the two raw material films by the method described above, which is further heated and softened. ) may be a protrusion sheet with apertures (see FIG. 5) consisting of three raw material films which are overlapped and thermally bonded from the tips of the protrusions of the protrusion sheet with apertures.

Alternatively, as a projection sheet with holes, a metal thin film (for example, metal foil, metal vapor deposited film, etc.) or a plastic film with metal thin film is adhered to a projection sheet with holes made of two or three raw films. It may also be attached through an agent layer.

In this invention, the convex projections of the perforated projection sheet have air chambers formed in shapes such as prismatic, cylindrical, elliptical, semicircular, or a combination thereof. Good to have. especially,
Its convex protrusion has a height of 3 to 20 mm, especially 4 to 18 mm.
mm, furthermore, about 8 to 15 mm, and the base area is 0.2 mm.
It is preferable that an air chamber is formed in a columnar shape, such as a columnar shape or an elliptical columnar shape, with a size of about 15 cm 2 to 15 cm ² , especially about 0.5 to 10 cm ² . In this invention, if the height of the convex projection becomes too low, the bottom of the seedling-growing box will come close to the ground and the insulation will be lost, which is not preferable.

The perforated protrusion sheet preferably has a large number of convex protrusions arranged over the entire surface such that the interval between the convex protrusions is about 2 to 20 mm, particularly about 4 to 15 mm.

In this invention, the protruding sheet with apertures must not have any apertures (which serve as drainage holes or ventilation holes) that penetrate from the front to the back in areas other than the protrusions of the sheet. However, the opening may have any shape or size, and in the present invention, the diameter may be 0.5 to 5 mm, particularly 1 to 4
It is preferable to have a substantially circular, elliptical, etc. opening of about mm. This protrusion sheet with perforations has 5 to 100 perforations per ^0.1m2 of this sheet.
In particular, it is preferable to have about 10 to 60 pieces.

The plastic raw material film that forms the perforated protrusion sheet is molded from thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, addition polymers such as polystyrene, and condensation polymers such as nylon and polyester. Any plastic film with a thickness of about 20 to 500 μm, especially about 30 to 300 μm may be used.

Therefore, the perforated protrusion sheet is a lightweight plastic sheet that is flexible, has cushioning and heat insulating properties, and also has water permeability and air permeability from the front side to the back side of the sheet.

In this invention, the porous sheet 3 has a large number of capillary-like fine pores inside the sheet, extending from the front side to the back side of the sheet, and has considerable water retention (water content) and drainage. Any known sheet may be used as long as it has water permeability.

As the porous sheet 3, the thickness of the sheet is approximately
The sheet is about 50μ to 5mm, especially about 100μ to 4mm, and has a water content such that it contains water in an amount of 50% or more, especially 60 to 300% by weight based on the weight of the sheet. Moreover, it is preferable to use a sheet that can allow excess water to permeate from the front side of the sheet to the back side.

Specific examples of the porous sheet include paper (e.g. Japanese paper, newsprint, filter paper, kraft paper, etc.);
Examples include woven fabrics, non-woven fabrics, seaweed-like or sponge-like sheets.

In addition, the porous sheet 3 may have a large number of apertures similar to the apertures 9 provided in the protrusion sheet 6 with apertures, if necessary.

In this invention, the seedling box 2 for rice seedlings 4 shown in FIG. It may be of any known type as long as it is a wooden or plastic box with a number of drainage or ventilation holes in the bottom.

In this invention, the state in which the perforated protrusion sheet 6 and the porous sheet 3 are laid and arranged along the ground surface between the seedling raising box 2 for the rice seedlings 4 and the ground 5 of the hotbed is a porous state. As long as the sheet 3 is placed below the bottom of the seedling raising box 2 and above the protrusion sheet 6 with openings, there is no particular limitation in other respects, but in this invention,
As shown in FIG. 1, it is recommended that the end of the protrusion sheet 6 with openings be raised up along the vertical wall of the hotbed house 1 at the corner of the hotbed house 1 to keep the seedling box warm. preferred from above.

Further, in this invention, the bottom surface of the seedling raising box 2 and the top surface of the porous sheet 3, or between the porous sheet 3 and the protrusion sheet 6 with openings, are not in complete contact with each other. It is also preferable that narrow voids necessary for drainage and ventilation be formed. For example, if a seedling growing box 2 has legs that protrude downward from a portion of the bottom of the box 2, a narrow gap can be formed between the bottom of the seedling growing box 2 and the porous sheet 3. It is preferable because

Note that the projection sheet 6 with perforations and the porous sheet 3 used in this invention are overlapped and joined together by dotting or the like so as not to be in close contact with each other over the entire surface. may be used in the hotbed of this invention.

If rice seedlings are raised in the hotbed of this invention, the rice seedlings will grow uniformly and quickly even in cold regions.

Furthermore, in the hotbed of the present invention, the wetness of the bottom of the seedling-growing box 2 and the temperature around the seedling-growing box 2 can be easily adjusted, which has the effect of reducing the agricultural work required for these purposes. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a situation in which a hotbed for raising seedlings of the present invention is formed in a hotbed house and rice seedlings are raised, and FIG. FIG. 2 is an enlarged cross-sectional view of an example of a hot bed.
FIG. 3 is a perspective view partially showing an example of a protrusion sheet with apertures, and FIG. 4 is a sectional view of the protrusion sheet with apertures. FIG. 5 is a sectional view showing another example of the protrusion sheet with openings. 1; Hotbed house, 2; Seedling box, 3; Porous sheet, 4; Rice seedlings, 5; Ground, 6; Projection sheet with openings, 7; Air chamber, 8; Convex projections, 9; Open holes Department,
10; Third film.

Claims (1)

[Claims] 1. In the hotbed greenhouse, there are many convex protrusions that form independent air chambers between the bottom of the rice seedling nursery box and the ground surface of the hotbed, and the convex protrusions are For seedling raising, a plastic sheet with many openings in other places and a porous sheet with capillary-like fine pores inside are stacked on top of each other with the porous sheet as an upper layer and placed along the ground surface. hotbed of.