JPH0242903A - Method for forming water cutoff layer in bottom of field and machine for forming two-stage type water cutoff layer therefor - Google Patents

Abstract

PURPOSE:To form a water cutoff layer at a prescribed point under the ground surface by separating plowed soil from subsoil into the upper and lower two stages, drilling and advancing a machine body, separately transferring the plowed soil and subsoil to the back, refilling the soil and simultaneously forming a film by a water cutoff material in the deepest part of the drilled part. CONSTITUTION:A surface soil of a field in the forward direction of a machine is removed by a driller (shovel) 3 for plowed soil 10, fed backward by a conveyor 5 for the plowed soil and subsoil 11 is drilled by a driller (shovel) 4 for the subsoil and fed backward by a conveyor 6 for the subsoil. A water cutoff material is sprayed from a spray blowing machine 7 on the bottom of a drilled part to form a water cutoff layer in the form of a film by a rolling pressure roller 8 following a stirrer 12. The plowed soil and subsoil fed backward by the conveyors for the plowed soil and subsoil are piled up on the water cutoff layer to restore the soil layer in the original form.

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a civil engineering method for agricultural land reclamation and a civil engineering machine used to carry out the method. Prevents water leakage in the layer below the effective soil layer, which is about 1 meter deep, where crop roots are active, and also prevents groundwater and spring water from rising from the layer below, and precisely controls soil moisture above it. This paper relates to a field infrastructure maintenance method that facilitates field infrastructure maintenance, and the civil engineering machinery used therein.

(Conventional technology) In ordinary dry paddy fields, farmers repeat plowing and puddling operations on the top soil layer (approximately 15 cm ± 5 cm thick) that is flooded with water every time they need it. Waterlogging is achieved by dispersing soil particles and blocking the pores in the plow bed layer to cause a sticky phenomenon. Therefore, paddy fields with high water permeability should be raked more often. This has already become a traditional rice paddy farming technique that has been around for about 1,000 years and is being spread throughout the country.

There is also a method of flooding called Tokowame, which uses heavy rolling pressure to crush the pores in the plow bed layer to prevent water leakage.

Furthermore, in order to create paddy fields that precisely control soil moisture within the rhizosphere up to 1 m underground in leaky fields, approximately 1 m of soil is excavated, water-stopping material such as vinyl is placed on the bottom and sides, and the soil is refilled. Attempts are being made to create plastic paddy fields by returning them.

(Problem to be Solved by the Invention) By the way, the roots of rice and wheat originally extend to a depth of approximately 1 meter underground. While puddling work prevents water leakage and impounds water, it also has the advantage of leveling the field, plowing in organic matter, developing soil nitrogen, and making rice planting easier. It also has the disadvantage of impeding the elongation and growth of rice roots, such as deterioration of soil chemistry (reduction of cultivated soil). Moreover, this agricultural work consumes a lot of energy and is a laborious agricultural work that must be carried out every year.

The water filling method prevents water leakage, but on the other hand, it causes hardening (when the Yamanaka hardness meter reads 26 or more, it is difficult for roots to grow), and this inhibits root growth. Nor can it be called an appropriate method.

Furthermore, vinyl paddy field construction using vinyl is used to sort and separate the cultivated soil and subsoil (approximately 0.8 to 1 m below the cultivated soil), and to backfill the storage area and original street for digging. requires a huge amount of effort and expense.

Therefore, the object of the present invention is to provide a method that can secure a sufficient permeability coefficient to prevent water leakage, does not destroy the soil structure, does not require plowing or bedding work that inhibits the growth of crop roots, and is inexpensive and quick. And labor-saving, water-stopping material made of various water-stopping materials (lime, cement, slag, bentonite, asphalt, water-repellent materials, etc.) adapted to the soil type at a point of 0.8 to 2 m below the ground. It is an object of the present invention to provide a method for forming a layer (impermeable layer) and a water stop layer forming machine for carrying out the method.

(Means for Solving the Problems) In order to achieve the above object, the method for forming a water stop layer at the bottom of a field according to the present invention provides a method for forming a water stop layer at the bottom of a field with a depth of 0.8 to 2 m. The excavation is carried out in two stages, separated into upper and lower stages to prevent the subsoil from mixing with the subsoil, and the excavated soil is transferred to the rear separately for the cultivation soil and subsoil, and the original soil layer is restored and backfilled at the rear. Spread, stir, compact and/or spray a water stop material at the bottom of the excavated area where the soil has been excavated to form a film of a low permeability layer or an impermeable layer that maintains a predetermined permeability coefficient. It is characterized by this.

In addition, 2 at the bottom of the field for carrying out the water stop layer forming method.
The staged water stop layer forming machine has means for excavating in two stages, upper and lower, so that the soil and subsoil do not mix while moving forward, and a means for transporting the excavated soil to the rear separately, separately from the soil and subsoil. means and
A means of restoring and backfilling the original soil layer backwards using the transferred soil, and spreading, stirring, compacting, and spraying a water stop material at the bottom of the excavation part where the subsoil has been excavated while moving forward. Alternatively, the present invention is characterized by comprising means for performing either one of the treatments to form a coating of a hardly permeable layer or an impermeable layer that maintains a predetermined permeability coefficient.

(Examples) The present invention will be described in detail below by way of examples with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a water stop layer forming machine 1 for achieving the object of the present invention, and the method of the present invention will be made clear by the description of the machine.

The first illustrated machine body includes a crawler type propulsion device 2, rotary excavation shovels 3 and 4 divided into upper and lower stages for cultivation soil and subsoil, and separately excavated soil 10 and subsoil. 11
conveyors 5 and 6 for transporting the excavated materials backwards (in the opposite direction of arrow 9) as they are excavated so as not to mix them;
and for spraying water-stopping material consisting of any one of lime, cement, slag, bentonite, asphalt, or water-repellent substances or a combination thereof on the back side of the excavated soil plate. It consists of a sprayer 7, an agitator 12 for mixing the sprayed water stop material with the soil, and a rolling roller 8 for forming a water stop layer as a coating.

When carrying out the work, prepare a ground at one end of the field to a depth of, for example, 1.2 m.
, a starting hole with a width of 3 m and a length of 3 m is provided, and the machine body is installed, and from then on, the machine body 1 may be propelled in direction 9 to perform the desired work, or from excavation for cultivation soil to As the process begins, the machine gradually descends to the excavated bottom of the subsoil, and can then move on to the desired task.

As is clear from Figure 1, the work performed by the machine is to first remove the field topsoil (including the plow bed layer in principle) with the soil excavator 3 in the forward direction of the machine, and then simultaneously It is later conveyed by conveyor 5. Next, the subsoil in the deep part of the field is excavated with a subsoil excavator 4, and this is conveyed later by a subsoil conveyor 6 in the same way as the soil.

At the bottom of the excavation area from which the subsoil has been removed, a water stop material is sprayed by a sprayer 7, and at the same time, the soil is stirred to a predetermined depth by an agitator 12. A water stop layer is formed using the water stop material sprayed as a coating. Alternatively, if necessary, a water-stop coating may be formed on the side wall or bottom of the excavation using a separately provided spraying machine (not shown).

At this time, the water-stopping material is supplied from the accompanying tank car through the pressure pipe, allowing the work to continue.

A water stop layer is sequentially formed at the rear of the machine body 1 as it moves forward in the direction 9. On top of the formed water stop layer, the subsoil conveyed later by the subsoil conveyor 6 is placed on top of the formed water stop layer. The soil transported by the soil conveyor 5 is piled up on top, and the original soil layer is successively restored.

In principle, this machine will work in a straight line from one end to the other, and commands such as turning at the other end will be given manually from the booth.

(Effects of the invention) By forming a water stop layer at the bottom of the field and at the same time forming a side wall permeation prevention membrane, leakage rice fields that are widely distributed in various regions of the country, namely old rice fields, sandy leakage rice fields, volcanic ash soil rice fields, and peat rice fields, can be improved. This prevents water leakage and contributes to improving productivity.

In this way, paddy fields can be flooded without puddling. In addition, drainage can be achieved by constructing a facility that combines both rice husk culverts and bullet culverts, and this water stop layer formation.
It is possible to create paddy fields with adjustable flooding. In this way, water leakage is prevented, underground temperature and underground drainage are ensured, and dry field direct seeding cultivation, which is the lowest-cost rice cultivation method, can be easily implemented in all rice fields in Japan.

Furthermore, since precise control of soil moisture can be achieved, it is possible to maintain appropriate soil moisture not only in rice but also in the main root group areas of all crops during the growing season of the crop, resulting in high quality and high yields. is promised. In addition, it is possible to constantly adjust the optimal soil moisture for all cultivated crops, and the wasteful flow of water, fertilizer nutrients, and herbicides is prevented.

Of the 2.88 million hectares of rice fields in Japan, 970,000 ha (33.6%) are highly permeable, and 170,000 ha (5.8%) are extremely permeable. This is the object to which the effects of the present invention are directly brought about. However, other types of rice fields, such as loamy clay and clay soil, with developed soil structures and cracks, as well as rice fields located next to rivers, creeks, and drainage canals, can leak vertically and horizontally if they are not plowed. , it is effective in preventing water leakage over a considerable area even in ordinary dry fields. In addition, the present invention is applicable not only to paddy fields but also to peat layers, sand dunes, and desert lands that cannot retain moisture and are considered barren.

(References) (1) Yasuo Takishima, Hiroshi Sakuma: Research on the effects of soil compaction and hardness on root thread development and growth of paddy rice, Agricultural Research Institute Report, B-21, 255 (2) Hiroshi Ide: Shallow layer Research on dry field direct sowing cultivation of paddy rice using bullet culverts and improvement of wheat cultivation, Dissertation 1-121 submitted to Tokyo University of Agriculture (198
2) (3) Hiroshi Ide: A new cultivation method for the development of soil structure in rice fields, Saga Agricultural Research Report, 20.63-81 (4) Patent No. 797480 “Ground tillage/surface no-tillage furrow seeding Crop cultivation method by method”

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the water stop layer forming machine of the present invention. ■ Machine body 2 Crawler-type propulsion device 3.4 Excavation rotary shovel for cultivation soil and subsoil, respectively 5.6... Conveyor 7 for cultivation soil and subsoil, respectively
...Injection spray machine ...Roller for compaction 9.
...Machine movement direction 10...Soil 11...Subsoil
12... Stirrer 13... Water stop layer

Claims (1)

[Claims] 1. To form a water stop layer at the bottom of the field, excavation is carried out in two stages, upper and lower, so that the soil and subsoil do not mix, and the excavated soil is separated into the soil and subsoil separately. At the same time, the soil layer is transferred backwards to restore the original soil layer and backfill, and at the same time, water stop material is sprayed, stirred, compacted, and/or sprayed at the bottom of the excavation area where the subsoil has been excavated. A method for forming a water stop layer at the bottom of a field, comprising: forming a film of a water-impermeable layer or an impermeable layer that maintains a predetermined water permeability coefficient. 2. The forming method according to claim 1, wherein the water stop material is any one of limes, cements, slags, bentonites, asphalts, or water-repellent substances, or a combination thereof. A method for forming a water stop layer at the bottom of a field. 3. The method for forming a water stop layer at the bottom of a field according to claim 1 or 2, wherein the predetermined water permeability coefficient is 10^-^5 cm/sec or less. 4. While moving forward, move the soil up and down 2 to prevent the soil from mixing with the subsoil.
A means for excavating in stages, a means for transferring the excavated soil backwards separately as soil and subsoil, and using the transferred soil to restore the original soil layer to the rear and backfill. A water-stopping material is sprayed, stirred, compacted and/or sprayed at the bottom of the excavated part where the subsoil is excavated while moving forward to create a low-permeability layer or an impermeable layer that maintains a predetermined permeability coefficient. A two-stage water stop layer forming machine at the bottom of a field, characterized by comprising means for forming a water permeable layer film.