JPH0212850Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a water-retaining sheet for raising seedlings, and particularly to a water-retaining sheet for raising seedlings suitable for use in raising rice seedlings in a seedling-raising box.

〓Background technology and its problems〓 With the modernization of agriculture, the automation of rice planting work is progressing, and rice planting using machines is becoming widespread. The seedlings used in such a rice transplanter are required to have a uniform growth rate, and if the seedlings grow unevenly, good rice transplantation will not be possible. That is, in order to be used in a rice transplanter, it is preferable that the number of seedlings within a determined area be approximately constant and that there be no variation in growth. In response to this purpose, it has become common to grow seedlings using seedling boxes.

When growing rice seedlings in a seedling box, conventionally, as shown in Figure 5, a plastic film 1 that prevents root elongation is first laid on top of the soil, and the seedlings are grown on top of this plastic film 1. I was trying to place Box 2. The seedling nursery box 2 is provided with a drainage hole 3 consisting of a small hole on the bottom for removing excess water and draining. I was trying to put 4 newspapers on the floor. and newspaper 4
Cultivating soil 5 was put on top, and seeds 6 were sown on top of this cultivating soil 5. The seeds 6 were covered with soil 7.

The disadvantage of raising seedlings using the conventional seedling box 2 is that it is not only time-consuming because the plastic film 1 must be spread on the soil in advance, but also that the sheet 1 protects the interior and bottom of the seedling box 2. Since the seedling growing box 2 is cut off from the ground, the inside of the seedling growing box 2 tends to dry out. For example, if watering is delayed for one day, the inside of the seedling growing box 2 will be severely lacking in water, and for example, the soil covering 7 will dry out. Then, as shown in Figure 6, the dry covering soil 7
There was a problem in that the seedlings 8 were lifted up by the germinated seedlings 8, and the seedlings 6 were separated from the soil 7, resulting in poor growth of the seedlings 8. This drawback is because the newspaper 4 laid out on the bottom of the seedling growing box 2 does not have sufficient water retention properties and cannot retain moisture.

In order to prevent the inside of the seedling growing box 2 from drying out and to prevent the covering soil 7 from lifting up as shown in FIG. As shown, the roots 9 break through the newspaper 4 and spread their roots into the soil below the box 2 through the small holes 3 on the bottom of the seedling box 2. Then, the task of stripping the seedlings 8 from the seedling growing box 2 becomes extremely troublesome, or the roots must be cut in advance. Furthermore, if the plastic film 1 is not used, there is a problem in that water is not maintained uniformly in the seedling growing box 2, resulting in uneven growth of the seedlings 8.

〓Purpose of the invention〓 The present invention was made in view of the above problems.It prevents the inside of the seedling nursery box from drying out, and also prevents the roots from extending into the soil under the box. The object of the present invention is to provide a water-retaining sheet for raising seedlings that allows seedlings to grow uniformly.

〓Summary of the invention〓 The present invention provides a water-retaining sheet for seedling-raising, which is placed on the bottom of a seedling-raising box with drainage holes and under the soil, which is provided with a sheet-like water-retentive polymer layer, and which is provided with a sheet-like water-retentive polymer layer. A water-retaining sheet for raising seedlings, characterized in that it has a three-layer structure in which a perforated plastic film is bonded to the lower side of the layer, and paper is bonded to the surface of the water-retaining polymer layer, the middle layer being a water-retaining sheet. The water-retaining polymer layer that makes up the container retains water evenly and prevents the inside from drying out, while the perforated plastic film on the bottom helps retain water and allows the roots of the seedlings to grow downward. In addition, the surface of the water-retaining polymer layer is protected by covering it with paper.

〓Example〓 The present invention will be described below with reference to an illustrated example.
FIG. 1 shows a water-retaining sheet 10 for raising seedlings according to this embodiment. As is clear from FIG. 1, this sheet 10 has a three-layer structure joined by dry lamination. The top layer is paper 1
It is composed of 1. This paper 11 protects the water-retaining polymer 12 made of powder underneath, and also absorbs and retains some water itself. A plastic film 13 is bonded to the underside of this water-retaining polymer layer 12. The plastic film 13 is provided with holes 14 for draining excess water to the bottom. As shown in FIG. 2, the holes 14 are provided in the plastic film 13 so as to be distributed at regular intervals.

When raising seedlings using such a water-retaining sheet 10, the water-retaining sheet 10 is laid on the top surface of the bottom plate of a seedling-raising box 15, as shown in FIG. The seedling raising box 15 is made of water or plastic, and drain holes 16 for draining water are formed at predetermined intervals on the bottom surface.
6 so that excess water is removed to the bottom of the box 15. Then, cultivating soil 17 is put on the upper side of the water retaining sheet 10, and seed rice 18 is sown on the upper surface of this cultivating soil 17. And this seed fir 1
8 is covered with soil 19. When water is applied from above the covered soil 19 in this state, the seed rice 18 germinates and grows to produce early seedlings 20 as shown in FIG. 4.

In this way, water retaining sheet 1 for seedling raising according to this embodiment
0 has a layer 12 made of a water-retaining polymer as its intermediate layer. This water-retaining polymer is composed of high-molecular compounds such as acrylic acid-vinyl alcohol copolymer, sodium polyacrylate polymer, and sodium acrylate acrylamide copolymer, and has high absorbency and low weight. It has the unique physical property of absorbing hundreds of times more water, and once it absorbs water, it does not flow back. Note that instead of the water-retaining polymer made of such a synthetic polymer, it is also possible to use a semi-synthetic water-retaining polymer. Semi-synthetic versions are composed of cellulosic or starch-based polymers. In general, semi-synthetic products are superior in water absorption speed, and synthetic products are superior in water absorption capacity and water retention.

Since the water-retaining sheet 10 is provided with such a water-retaining polymer layer 12, this polymer 12 absorbs and retains water applied through the soil cover 19, and the water-retaining polymer 12 of this water-retaining sheet 10 This effectively and reliably prevents the interior of the seedling growing box 15 from drying out. Therefore, the covered soil 19 is prevented from being lifted up by the dry and germinated seedlings 20. Furthermore, the seedlings 20 will not wither due to a short-term delay in irrigation. Furthermore, since the water retaining sheet 10 makes the distribution of moisture in the seedling nursery box 15 uniform, uneven growth of the seedlings 20 can be prevented, and suitable early seedlings 20 can be grown using a rice transplanter. It becomes like this.

Furthermore, the plastic film 13 constituting the bottom layer of the water-retaining sheet 10 can prevent roots from extending to the bottom of the box through the drainage hole 16 in the bottom plate of the seedling box 15, eliminating the need for root cutting. It disappears. Furthermore, when taking out the seedlings 20 from the seedling growing box 15 and attaching them to the rice transplanter, the water retaining sheet 15 allows the seedlings 20 to be easily taken out as shown in FIG. 4, improving work efficiency. become.

Although the present invention has been described above with reference to an illustrated embodiment,
The present invention is not limited to the above embodiments, and various modifications can be made based on the technical idea of the present invention. For example, the above embodiment relates to a water-retaining sheet for a box for growing rice seedlings, but the present invention can also be applied to a water-retaining sheet for a box for growing vegetable seedlings.

Effects of the invention As described above, the present invention includes a sheet-like water-retaining polymer layer, a perforated plastic film is bonded to the underside of the water-retaining polymer layer, and the surface of the water-retaining polymer layer is It has a three-layer structure by bonding paper to the top. Therefore, it is possible to uniformly retain water by the water-retaining polymer layer constituting the intermediate layer, and the water-retaining property of this water-retaining polymer layer can be assisted by the perforated plastic film on the lower side. Since a larger amount of water can be held evenly, it is possible to prevent the inside of the seedling box from drying out. In addition, the perforated plastic film on the bottom prevents the roots of the seedlings from extending into the soil below through this water-retaining sheet and the drainage holes formed on the bottom of the seedling box. There is no need to carry out any additional work, and there is no need to spread a polymer sheet on the bottom of the seedling box. Furthermore, since the structure is such that paper is bonded to the surface of the water-retaining polymer layer, it is possible to reliably protect the surface of the water-retaining polymer layer by covering it with paper, making it easier to handle. becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing a water-retaining sheet for seedling raising according to an embodiment of the present invention, Fig. 2 is a bottom view of the same, and Fig. 3 is a diagram of a seedling-raising box for raising seedlings using this water-retaining sheet for raising seedlings. Fig. 4 is a vertical cross-sectional view, Fig. 4 is an external perspective view showing the operation of taking out the seedlings grown in the seedling nursery box, and Fig. 5 is a longitudinal sectional view.
The figure is a vertical cross-sectional view of a conventional seedling-raising box, Figure 6 is a vertical cross-sectional view of the same with the covered soil raised up, and Figure 7 is a vertical cross-section of the seedling-raising box showing the state in which the roots are protruding into the soil below. It is a diagram. In addition, in the symbols used in the drawings, 10... water-retaining sheet, 11... paper, 12... water-retaining polymer layer,
13... Plastic film, 14... Hole, 1
5... Seedling box, 16... Drainage hole, 17... Cultivating soil,
18...seeds, 19...covering soil, 20...seedlings.

Claims (1)

[Scope of utility model registration request] A water-retaining sheet for seedling-raising that is placed on the bottom of a seedling-growing box with drainage holes and below the soil, is provided with a sheet-like water-retaining polymer layer, and a perforated plastic layer is provided on the underside of the water-retaining polymer layer. A water-retaining sheet for raising seedlings, characterized in that it has a three-layer structure in which films are bonded together and paper is bonded to the surface of the water-retaining polymer layer.