JP2013039125A - Underground irrigation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underground irrigation system that can be suitably used on a slope land since the amount of moisture in a plough layer can be kept as even as possible without needing equipment such as water-table management equipment.SOLUTION: The underground irrigation system 10 includes a sealing member 12 to be buried in the ground of a cropland 200 and supplies water from the underground to keep the amount of moisture in soil in a state appropriate for the growth of a plant. The sealing member is formed of a material having a sealing property in an elongated groove-like shape and is buried in the ground with its longitudinal direction being along the slope of the cropland 200. A water-holding member 14 having a water-absorbing property and water-holding property is provided at the bottom of the inside of the sealing member 12, and a water supply member 16 is disposed through the water-holding member 14. In the underground irrigation system 10, water from a water supply source 30 is supplied to the water-holding member 14 by the water supply member 16 during the irrigation. The water absorbed and held by the water-holding member 14 is soaked up and supplied to the soil above by capillary action.

Description

  The present invention relates to an underground irrigation system, and more particularly to an underground irrigation system that supplies water from the underground to keep the moisture content of soil appropriately.

  Conventionally, surface irrigation for supplying water from the ground surface to the soil using a perforated hose or a sprinkler or the like laid on the ground surface is generally used for irrigation of fields and the like. Here, the water supplied to the soil by surface irrigation will also moisten the soil surface and plant surface, but most of this water will only evaporate into the atmosphere (ie, surface evaporation). Waste of money occurs. In addition, the mud of the soil may hinder the work, and may cause problems such as mud splashing and crust (soil film) formation on the soil surface. Further, in the case of house cultivation, the moisture in the house is excessively increased by moisture evaporated from the soil surface, which may cause plant diseases.

  On the other hand, in underground irrigation in which water is supplied from the underground, the supplied water hardly evaporates from the soil surface, so that waste of water can be reduced and water resources can be used efficiently. Moreover, the malfunction resulting from surface irrigation, such as the soil becoming muddy or the humidity in the house rising excessively, does not occur. For this reason, various underground irrigation systems have been proposed in recent years.

For example, Patent Document 1 discloses a conventional underground irrigation system. In this underground irrigation system, a water-impervious member formed in a container shape with an upper opening is buried in the ground such as a cultivated land. Then, water is supplied to the inside of the water-impervious member to form a gravity water-state soil portion, and water is supplied from the gravity water-state soil portion to the plant rhizosphere soil by capillary action. As an example, a horizontal tubular (horizontal container-shaped) water shielding member having an opening on the upper side is used.
JP 2010-29072 A [A01G 25/00]

  In the technique of Patent Document 1, a soil part in a gravitational water state is formed in the water-impervious member of the upper opening, so that if the water-impervious member is installed at an angle, gravity water in the water-impervious member spills from the opening during underground irrigation. Moreover, since the amount of gravity water in the water-impervious member is biased depending on the location, it is difficult to keep the moisture content of the soil uniform. For this reason, in the technique of patent document 1, it is necessary to install a water shielding member horizontally, and when applying a system to the cultivation land (inclined land) which has an inclination, the exact (strict N) I had to level out and install a water-blocking member along the contour line. That is, in the technique of Patent Document 1, there is a problem that there is a great geographical restriction on the arrangement of the water shielding members.

  Furthermore, in the technique of Patent Document 1, the water level management of the gravity water in the water-impervious member is performed by the water level management device. However, when this underground irrigation system is applied to an inclined land, it is evenly applied to the soil. It is desirable that the level of gravity water in each water shielding member can be adjusted individually so that water can be supplied. However, if a water level management device is provided for each water shielding member for that purpose, the cost is significantly increased.

  Therefore, the main object of the present invention is to provide a novel underground irrigation system.

  Another object of the present invention is to provide an underground irrigation system that can be suitably used for sloping land.

  Still another object of the present invention is to provide an underground irrigation system that can supply water evenly to the soil without using equipment such as a water level controller.

  The present invention employs the following configuration in order to solve the above problems. Note that reference numerals in parentheses, supplementary explanations, and the like indicate correspondence relationships with embodiments described later to help understanding of the present invention, and do not limit the present invention in any way.

  1st invention is formed in the container shape of an upper side opening, and is embedded through the water-impervious member inclined and embedded in the ground of the cultivated land, and the water-retaining member provided at least at the bottom of the water-impervious member, the water-retaining member An underground irrigation system including a water supply member that is disposed in a water shielding member and supplies water supplied from a water supply source to a water retention member.

  In the first invention, the underground irrigation system (10) includes a water-impervious member (12) embedded in the ground of the cultivated land (200), and supplies water from the underground to grow moisture in the soil. To keep it in a proper state. The water-impervious member is formed in a container shape having an upper opening by a material having water-impervious properties, and is embedded in the ground along the slope of the cultivated land, for example. A water retaining member (14) is provided, for example, at the bottom of the water shielding member. The water retaining member is made of a material having water absorption and water retaining properties, and is provided over the entire length of the water shielding member in the length direction, for example. In addition, a water supply member (16) is disposed inside the water shielding member via a water retention member. A water supply member is a pipe line which supplies the water supplied from the water supply source (30) to a water retention member, for example, is mounted on the upper side of a water retention member. In such an underground irrigation system, at the time of irrigation, water supplied from the water supply source to the water supply member is supplied to the water retention member, and the water is absorbed by the water retention member. Then, the water retained by the water retaining member is sucked up and penetrated into the upper soil by a capillary phenomenon, and a soil portion (38) in a capillary water state is formed in the upper soil.

  According to the first invention, the water supplied by the water supply member is absorbed or permeated into the water retention member, and the water retained by the water retention member is supplied to the soil by capillary action. Even so, it is possible to keep the water content of the soil layer as uniform as possible. In other words, the underground irrigation system can be suitably used even on sloping land.

  Moreover, since there is no need to use special equipment such as a water level management device, equipment costs and maintenance costs can be reduced.

  A second invention is dependent on the first invention, and further includes a water storage means provided on the downstream side of the water supply member and into which surplus water inside the water supply member flows.

  In 2nd invention, the downstream end part of the water supply member (16) is connected to the water storage means (34) installed in the downstream rather than the water supply member, for example via the water distribution pipe (32). In the embodiment, the water storage means is a water storage tank (34), and surplus water that has not been supplied from the water supply member to the water retention member is discharged to the water storage tank, and the water storage tank receives the water sent from the water supply member therein. Store in.

  According to the second aspect of the invention, since the surplus water remaining inside the water supply member without being able to supply water is stored by the water storage means, the water resources can be efficiently used by reusing the water. it can.

  A third invention is dependent on the second invention, and further includes a circulation means for returning the water stored by the water storage means to the water supply source.

  In the third invention, the underground irrigation system (10) is provided with a circulation means for returning the water stored by the water storage means (34) to the water supply source (30). In the embodiment, the water stored in the water storage tank (34) is sent to the water supply source (30) by the pump (40).

  A fourth invention is dependent on the second or third invention, wherein the water supply member includes a perforated pipe having a plurality of through holes formed in the pipe wall, and the perforated pipe is an excess inside the water shielding member. The water collecting member is also used as a water collecting member, and surplus water collected by the water collecting member is discharged to the water storage means.

  In 4th invention, a water supply member (16) contains the perforated pipe | tube (24) used as a water collection member (36). The perforated tube is formed of synthetic resin, synthetic rubber, or the like, and a plurality of through holes (26) are formed on the tube wall. At the time of irrigation, water supplied from the water supply source (30) to the perforated pipe is supplied to the water retaining member through the through hole. Further, when there is excessive water in the soil due to rain or the like, water accumulated in the water shielding member is collected into the perforated pipe through the through hole. Then, the water collected inside the perforated pipe is discharged to the water storage means (34), and the water storage means stores the water sent from the perforated pipe therein.

  According to the fourth aspect of the invention, the surplus water remaining inside the water-impervious member is stored by the water storage means, so that the water resource can be used more efficiently by reusing the water.

  5th invention is formed in the container shape of an upper side opening, the water-impervious member embed | buried under the ground of a cultivated land, the water-retaining member provided in the at least bottom part in a water-impervious member, and inside a water-impervious member via a water-retaining member A water supply member for supplying water supplied from a water supply source to the water retention member, a water level detection means for detecting the water level supplied from the water supply member to the water retention member, and a detection result of the water level detection means An underground irrigation system comprising water supply control means for controlling water supply from the water supply member to the water retention member.

  In the fifth invention, the underground irrigation system (10) includes a water-impervious member (12) embedded in the ground of the cultivated land (200), and supplies water from the underground to grow moisture in the soil. To keep it in a proper state. The water-impervious member is formed in a container shape having an upper opening made of a material having water-impervious properties, and is embedded in the ground of the cultivated land. A water retaining member (14) is provided, for example, at the bottom of the water shielding member. The water retaining member is made of a material having water absorption and water retaining properties, and is provided over the entire length of the water shielding member in the length direction, for example. In addition, a water supply member (16) is disposed inside the water shielding member via a water retention member. A water supply member is a pipe line which supplies the water supplied from the water supply source (30) to a water retention member, for example, is mounted on the upper side of a water retention member. Further, for example, a water level detection means (62) for detecting the water level of water supplied from the water supply member to the water retention member is provided at the downstream end of the water supply member, and the water level is provided at the upstream end of the water supply member. A water level control means (64) for controlling the water supply from the water supply member to the water retention member based on the detection result of the detection means is provided. In such an underground irrigation system, at the time of irrigation, water supplied from the water supply source to the water supply member is supplied to the water retention member, and the water is supplied to the water retention member from the upstream side to the downstream side of the water supply member. Absorbed. At this time, the water retained by the water retaining member is sucked up and penetrated into the upper soil by a capillary phenomenon, and a soil portion (38) in a capillary water state is formed in the upper soil. Further, for example, when the water supplied from the water supply member is retained in the water retention member at the downstream end of the water supply member, the water level detected by the water retention member is detected by the water level detection means, and the detection result is determined according to the detection result. Control water supply from the water supply member.

  According to the fifth aspect of the invention, the water supplied by the water supply member is absorbed or penetrated into the water retention member, and the water retained by the water retention member is supplied to the soil by capillary action, so that the water shielding member is inclined and installed. Even so, it is possible to keep the water content of the soil layer as uniform as possible. In other words, the underground irrigation system can be suitably used even on sloping land.

  Furthermore, by detecting the water level retained by the water retention member by the water level detection means and controlling the water supply from the water supply member according to the detection result, wasteful discharge of water downstream from the system can be prevented. Water resources are not wasted.

  6th invention is dependent on 5th invention, a water-impervious member is inclined and embedded in the ground of a cultivated land, a water level detection means is installed in the inclination lower end of a water-impervious member, and a water supply control means is And a water supply stop means for stopping water supply from the water supply member to the water retention member based on the detection result of the water level detection means.

  In the sixth invention, the water-impervious member (12) is embedded in the ground of the cultivated land (200), and the water level detecting means (62) is provided at the lower end of the inclined surface. And when the water level of the detection result of the water level detection means is higher than the set water level (W), the water supply control means (64) stops water supply from the water supply member (16) to the water retention member (14).

  According to the sixth aspect of the present invention, after the start of water supply, the water supply can be stopped at the time when the water is supplied to the entire water retaining member from the upper end of the water shielding member to the lower end of the inclined member, thereby preventing excessive or insufficient water supply. be able to.

  According to a seventh aspect of the present invention, there is provided a water-impervious member that is formed in a container shape having an upper opening and is embedded in an inclined manner in the ground of the cultivated land, a water-retaining member provided at least at the bottom of the water-impervious member, An underground irrigation system including a water supply member that is disposed in a water-impervious member with a water retention member interposed between the water supply member and a water supply member.

  In the seventh invention, the underground irrigation system (10) includes a water-impervious member (12) embedded in the ground of the cultivated land (200), and supplies water from the underground to grow moisture in the soil. To keep it in a proper state. The water-impervious member is formed in a container shape having an upper opening by a material having water-impervious properties, and is embedded in the ground along the slope of the cultivated land, for example. A water retaining member (14) is provided, for example, at the bottom of the water shielding member. The water retaining member is made of a material having water absorption and water retaining properties, and is provided over the entire length of the water shielding member in the length direction, for example. In addition, a water supply member (16) is disposed inside the water shielding member with a water retaining member interposed between the water shielding member and the bottom of the water shielding member. A water supply member is a pipe line which supplies the water supplied from the water supply source (30) to a water retention member, for example, is mounted on the upper side of a water retention member.

  According to the seventh aspect, the same effect as the first aspect can be obtained.

  The eighth invention is dependent on the seventh invention, and in the ground of the cultivated land, the water supply member is placed on the soil that is not cultivated with the water supply member interposed therebetween, and the vertical position of the water supply member is positioned. I tried to do it.

  In 8th invention, at least one part of the water-impervious member (12) is arrange | positioned above the soil which is not dug up in the ground of a cultivated land (200), and a water supply member (16) is the water-impervious member. It is placed on the upper side of the soil that has not been dug up. In this way, when the underground irrigation system is constructed, the water retaining member below the water supply member is not compressed due to the weight of the water supply member or the soil, and the water supply member does not move downward. The position in the direction can be reliably positioned.

  According to the eighth aspect of the invention, since the distance from the bottom of the water-impervious member to the water supply member is stabilized from the upper inclined end to the lower inclined end of the water-impervious member, the amount of water retained by the water retaining member can be made uniform. . Therefore, the moisture content of the soil portion in the capillary water state is not biased, and the moisture content of the soil layer can be more evenly maintained.

  In the ninth aspect of the invention, the water supply member is placed on the upper side of the second position which is higher than the lowest first position in the bottom portion in the water shielding member.

  In the ninth invention, for example, the second bottom plate (60) which is higher in a step shape than the lowest bottom plate (18) among the bottoms in the water shielding member (12) is formed in a part of the water shielding member (12). The water supply member (16) is placed on the upper side of the second bottom plate.

  According to the ninth aspect, the vertical position of the water supply member can be easily and reliably positioned.

  A tenth aspect of the invention is dependent on the first to ninth aspects of the invention, and further includes a partition portion that divides the bottom portion in the water shielding member at a predetermined interval in the installation direction of the water shielding member.

  In the tenth invention, a partition (46) is formed at the bottom of the water-impervious member (12). The partition portion is made of a material having water shielding properties, and is formed to protrude from the inner surface side of the bottom portion of the water shielding member, for example, and is arranged at a constant interval in the installation direction of the water shielding member. The partition section defines a space on the inner surface side of the bottom of the water-impervious member, and a water retaining member (14, 14a) is provided in each section partitioned by the partition section.

  According to the tenth invention, the water supplied from the perforated pipe and accumulated in each part partitioned by the partition part is absorbed by the water retaining member provided in each part. The amount of water absorbed by the member can be kept substantially uniform. Therefore, the water content of the soil layer can be kept more even.

  An eleventh invention is dependent on any one of the first to tenth inventions, and the water retention member includes soil of cultivated land.

  In the 11th invention, the bottom part in the water-impervious member (12) is filled with the soil comprised by the component similar to the soil of a cultivated land (100) as a water retention member (14), for example. For example, the water supplied from the water supply member (16) penetrates into the soil inside the water shielding member, becomes capillary water or gravity water, stays inside the water shielding member, and inside the water shielding member, A soil portion (50) in a capillary water state or a gravity water state is formed. And the water | moisture content of this soil part is sucked up and permeate | transmitted to the upper soil by the capillary phenomenon, and forms the soil part (38) of a capillary water state in the upper soil.

  A twelfth invention is dependent on any one of the first to eleventh inventions, and the water supply member includes a perforated pipe that is also used as a water collecting member for collecting excess water inside the water shielding member. A hydrophobic portion is provided on the upper side of the hole tube.

  In the twelfth invention, the water supply member (16) includes a perforated pipe (24) that is also used as a water collecting member (36) for collecting surplus water inside the water shielding member (12). A hydrophobic portion (108) is provided on the upper side of the tube, that is, on the upper and upper sides of the perforated tube. Then, the water that has oozed out from the ground of the cultivated land (200) into the hydrophobic portion is collected in the perforated pipe, and the water that has flowed through the perforated pipe is discharged into, for example, the water storage tank (34).

  A thirteenth aspect of the present invention is a water-impervious member formed in a container shape with an upper opening and buried in the ground of a cultivated land, a water-retaining member provided at the bottom of the water-impervious member, and a water-retaining member in the water-impervious member. A subsurface irrigation system comprising a water supply member that is disposed in a row and supplies water supplied from a water supply source to a water retention member.

  In the thirteenth aspect, the underground irrigation system (10) includes a water-impervious member (12) embedded in the ground of the cultivated land (100), and supplies water from the underground to grow moisture in the soil. To keep it in a proper state. The water-impervious member is formed in a container shape having an upper opening by a material having water-impervious properties. A water retaining member (14) is provided at the bottom of the water shielding member. The water retaining member is made of a material having water absorption and water retaining properties, and is provided over the entire length of the water shielding member in the length direction, for example. In addition, a water supply member (16) is disposed inside the water shielding member via a water retention member. A water supply member is a pipe line which supplies the water supplied from the water supply source (30) to a water retention member, for example, is mounted on the upper side of a water retention member. In such an underground irrigation system, at the time of irrigation, water supplied from the water supply source to the water supply member is supplied to the water retention member, and the water is absorbed by the water retention member. Then, the water retained by the water retaining member is sucked up and penetrated into the upper soil by a capillary phenomenon, and a soil portion (38) in a capillary water state is formed in the upper soil.

  According to the thirteenth invention, the same effect as the first invention is obtained.

  According to this invention, the water supplied by the water supply member is absorbed or permeated into the water retention member, and the water retained by the water retention member is supplied to the soil by capillary action. There are no restrictions, and it is possible to suitably use the underground irrigation system even on sloping land.

  Moreover, since it is possible to supply water evenly to the soil without using special equipment such as a water level management device, it is possible to reduce equipment costs and maintenance costs.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is an illustration figure which shows the underground irrigation system of one Example of this invention. It is an illustration figure which shows the underground irrigation system of FIG. It is an illustration figure which shows the underground irrigation system of FIG. It is an illustration figure which shows the underground irrigation system of FIG. (A) is an illustration showing the flow of water when the perforated pipe is supplied in the underground irrigation system of FIG. 1, and (b) is the water when collecting the perforated pipe in the underground irrigation system of FIG. It is an illustration figure which shows the flow of. It is an illustration figure which shows the flow of the water supplied to a water retention member from the through-hole of a perforated pipe. It is an illustration figure which shows the flow of the water at the time of circulation of the stored water in the underground irrigation system of FIG. It is an illustration figure which shows the underground irrigation system which is another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system of FIG. It is an illustration figure which shows a mode that the water-impervious member of the underground irrigation system of FIG. 16 is installed. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows a mode that the underground irrigation system of FIG. 19 is constructed using a construction apparatus. It is an illustration figure which shows a mode that the water-impervious member and water supply member of the underground irrigation system of FIG. 19 are installed. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows a mode that the water shielding member and water supply member of the underground irrigation system of FIG. 22 are installed. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the water level detection means of the underground irrigation system of FIG. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the water level management device of the underground irrigation system of FIG. It is a schematic sectional drawing which shows operation | movement of the water level management device of the underground irrigation system of FIG. 28, (a) shows the state which the water supply port opened, (b) shows the state which the water supply port closed. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention. It is an illustration figure which shows the underground irrigation system which is further another Example of this invention.

  Referring to FIGS. 1 and 2, an underground irrigation system 10 (hereinafter, also simply referred to as “system 10”) according to an embodiment of the present invention is an underground of a cultivated land (inclined land) 200 having an inclination. Including a water-impervious member 12 buried in the water and a water-retaining member 14 provided at the bottom of the water-impervious member 12, supplying water from the underground to keep moisture in the soil in a state suitable for plant growth. . Although details will be described later, in this system 10, the water supplied to the inside of the impermeable member 12 by the water supply member 16 is absorbed by the water retention member 14, and the water retained by the water retention member 14 is supplied to the soil by capillary action. .

  As shown in FIG. 1 to FIG. 3, the water shielding member 12 is formed in a container shape with an upper opening by a material having water shielding properties such as a synthetic resin such as polyethylene and polyvinyl chloride, and a metal such as stainless steel, It is buried in the ground along the 200 slope.

  For example, in this embodiment, the water-impervious member 12 is formed in an elongated groove shape in which the side plate 20 rises slightly outward from both side ends of the bottom plate 18, and the longitudinal direction thereof follows the inclination of the cultivated land 200. Buried inside. As the water-impervious member 12, for example, a member formed by bending or curving a water-impervious sheet made of a water-impervious material as described above may be used. As an example, the width of the bottom plate 18 of the water shielding member 12 is 120 mm, for example, and the height of the side plate 20 (depth of the water shielding member 12) is 150 mm, for example. Further, the width of the opening 22 on the upper side (top end) of the water shielding member 12 is set larger than the width of the bottom plate 18 and is, for example, 300 mm.

  The water-impervious member 12 is arranged for each ridge 202 set up along the slope of the cultivated land 200 so as to extend along the root zone of the plant, and extends along the ridge 202 to the vicinity of both ends of the cultivated land 200. The water members 12 are arranged so as to be arranged at a predetermined interval. In FIG. 1, for the purpose of illustration, four water-impervious members 12 are arranged side by side in the cultivated land 200, but this is merely an example, and the number of the water-impervious members 12 disposed is appropriately set as necessary. Can be changed. Further, it is not always necessary to dispose the water shielding member 12 for each ridge 202. In the cultivated land 200 having a plurality of ridges 202, the water shielding member 12 may be disposed at a ratio of one to two ridges 202. Good.

  As an example, the space | interval of the adjacent water-impervious members 12 shall be 500-2000 mm, for example. Moreover, the distance from the baseplate 18 of the water-impervious member 12 to the ground surface is, for example, 100 mm-800 mm.

  However, the size, the number of arrangement, the arrangement depth, the arrangement interval, and the like of the water-impervious member 12 are not limited to these numerical values, and depend on the area of the cultivated land 200 to which the system 10 is applied, soil components, climatic conditions, and the like. Is set as appropriate. This is the same in other embodiments described later.

  A water retaining member 14 is provided at the bottom of the water shielding member 12. And the water supply member 16 is arrange | positioned in the water-impervious member 12 through this water retention member 14. However, as described above, since the water-impervious member 12 is formed in a container shape having an upper opening, the inside of the water-impervious member 12 in this case is a concept included on the upper side of the water-impervious member 12, and the water-impervious member It should be noted that the bottom portion in 12 is a concept included above the bottom plate 18 of the water shielding member 12.

  As shown in FIGS. 1, 3, and 4, the water retaining member 14 is made of a material having water absorption and water retaining properties, and has a bottom in the water shielding member 12 over the entire length of the water shielding member 12. That is, it is arranged on the upper side of the bottom plate 18. As an example, the water retention member 14 may be a general-purpose water retention agent made of a highly water-absorbing polymer such as sodium polyacrylate, or a mixture of such a water retention agent and soil. The thickness (height) of the water retaining member 14 is, for example, 50-100 mm.

  Further, the water supply member 16 is for supplying (water supply) the water supplied from the water supply source 30 to the water retention member 14, and includes a perforated pipe 24 that forms a water channel passing through the water shielding member 12.

  For example, in this embodiment, the perforated tube 24 is formed of a synthetic resin such as polyethylene or polyvinyl chloride, synthetic rubber, or the like, and is placed on the upper side along the water retaining member 14. In the perforated tube 24, a plurality of through holes 26 are randomly distributed over the entire tube wall, and water in the perforated tube 24 is supplied to the water retaining member 14 through the through holes 26. As an example, the outer diameter of the perforated tube 24 is, for example, 5-30 mm. The through hole 26 is formed in a circular shape, and the size thereof is, for example, 1-5 mm in diameter. Moreover, although illustration is abbreviate | omitted, the outer surface of the perforated pipe | tube 24 is covered with the root-proof sheet | seat which consists of a nonwoven fabric etc.

  However, the shape, size, formation position, number, and the like of the through-holes 26 are appropriately set according to the soil components of the cultivated land 200 to be applied, and the perforated pipe 24 can be adjusted and changed. It is possible to control the amount of water supplied from the water to the water retaining member 14.

  As shown in FIGS. 1 and 2, the upstream end portion of the perforated pipe 24 is connected to a water supply source 30 disposed on the upper side of the perforated pipe 24 via the first water distribution pipe 28. The first water distribution pipe 28 is a pipe that sends the water supplied from the water supply source 30 to the perforated pipe 24, and is formed by appropriately connecting a plurality of straight pipes, flexible pipes, joints, and the like. The water supply source 30 is a water supply tank 30 that stores water to be supplied to the cultivated land 200, and is installed on the ground, for example. The water supply tank 30 is connected to, for example, an agricultural water pipe (not shown), and stores water sent from the agricultural water pipe therein. The amount of water stored in the water supply tank 30 is appropriately set depending on the area of the cultivated land 200 and the like, and a certain amount or more of water is always stored in the water supply tank 30.

  On the other hand, the downstream end portion of the perforated pipe 24 is connected to the water storage means 34 disposed below the perforated pipe 24 via the second water distribution pipe 32. The second water distribution pipe 32 is a pipe that sends the water sent from the perforated pipe 24 to the water storage means 34, and is formed by appropriately connecting a plurality of straight pipes, flexible pipes, joints, and the like. The water storage means 34 is a water storage tank 34 that stores the water sent from the second water distribution pipe 32 therein, and is installed on the ground, for example. As will be described in detail later, surplus water remaining inside the perforated pipe 24 without being supplied with water is discharged to the water storage tank 34 via the second water distribution pipe 32. Further, in this system 10, the perforated pipe 24 is also used as the water collecting member 36 for collecting surplus water in the water shielding member 12, so that the perforated pipe 24 collects the details as will be described later. Excess water in the impermeable member 12 that has been drained is discharged to the water storage tank 34 via the second water distribution pipe 32.

  Referring to FIGS. 3 to 6, in such a system 10, during irrigation, the valve (not shown) provided in the water supply tank 30 is manually opened and closed, for example, to close the first water supply tank 30. Water is supplied to one water distribution pipe 28. However, water may be automatically supplied from the water supply tank 30 during a predetermined time period using a solenoid valve, a timer, or the like, and the physiological condition of the cultivated crop is monitored to supply water. Alternatively, the amount of water taken from the water supply tank 30 may be adjusted as appropriate so that water is constantly supplied.

  As shown in FIG. 5A, the water supplied from the water supply tank 30 to the first water distribution pipe 28 flows into the perforated pipe 24 and passes through the perforated pipe 24 over the entire length of the water shielding member 12. 6, as shown in FIG. 6, the gas passes through the through-holes 26, goes out of the perforated pipe 24, and is supplied (supplied) to the inside of the water shielding member 12. When water is supplied from the perforated pipe 24 to the inside of the water shielding member 12, the water penetrates into the soil and accumulates at the bottom of the water shielding member 12. Then, the water accumulated at the bottom of the water-impervious member 12 is mixed with the water retaining member 14 and the water is absorbed by the water retaining member 14. Then, with the passage of time, the water (moisture) retained (included) gradually by the water retaining member 14 is sucked up and permeated into the upper soil by capillarity, whereby the water is retained in the soil above the water retaining member 14. A soil portion 38 in a capillary water state is formed.

  Here, the water content of the soil portion 38 in the capillary water state varies depending on the amount of water retained in the water-impervious member 12, but in this system 10, the water supplied into the water-impervious member 12 is temporarily retained. Since the water retained by the water retaining member 14 is absorbed by the member 14 and sucked up into the upper soil by the capillary phenomenon, the water in the water shielding member 12 is maintained even when the water shielding member 12 is inclined. Neither spillage nor the amount of water held in the water-impervious member 12 is biased between the upper side and the lower side of the slope. That is, the amount of water retained in the water shielding member 12 is kept substantially equal. Therefore, for example, by keeping an appropriate amount of water supplied (absorbed) to the water retention member 14 in accordance with a plant cultivated on the cultivated land 200, the soil portion 38 having an optimal amount of water for the plant is cultivated 200. Can be realized.

  Further, in this system 10, even when excessive water is supplied from the water supply tank 30 to the perforated pipe 24 (the water supply member 16) during irrigation, the surplus water remaining inside the perforated pipe 24 without being able to be supplied is first. 2 is discharged to the water distribution pipe 32. And the 2nd water distribution pipe 32 sends the water sent from the perforated pipe 24 to the water storage tank 34, and the water storage tank 34 stores the water sent from the 2nd water distribution pipe 32 in the inside.

  Furthermore, in this system 10, when excessive water is supplied from the perforated pipe 24 into the water-impervious member 12, or when excessive water is given to the soil by natural rainfall or the like, the surplus water is impermeable. When the water retaining member 14 is saturated with water by accumulating in the member 12, the water that has not been absorbed by the water retaining member 14 is collected into the perforated pipe 24 (water collecting member 36) through the through hole 26. Then, when water is collected inside the perforated pipe 24, the water is discharged to the second water distribution pipe 32 through the perforated pipe 24 as shown in FIG. And the 2nd water distribution pipe 32 sends the water sent from the perforated pipe 24 to the water storage tank 34, and the water storage tank 34 stores the water sent from the 2nd water distribution pipe 32 in the inside.

  As described above, according to this embodiment, the water supplied into the water-impervious member 12 is absorbed by the water retaining member 14 and the water (water) retained by the water retaining member 14 is supplied to the soil by capillary action. Therefore, even if the water shielding member 12 is inclined and embedded, the moisture content of the soil portion 32 in the capillary water state is not biased. Therefore, in the cultivated land 200 of the same system 10, the water content of the soil layer can be kept as uniform as possible. That is, the system 10 can be suitably used for the cultivated land 200 having an inclination.

  Moreover, for example, when the underground irrigation system is applied to an inclined land, it is necessary to individually adjust the water level of the gravitational water in each water-impervious member by a water level controller as in Patent Document 1 described above. According to this embodiment, the amount of water retained in the water-impervious member 12 can be kept substantially even without using special equipment such as a water level controller, so that the equipment cost and maintenance cost Etc. can be reduced.

  Further, in this system 10, a water storage tank 34 is provided on the downstream side of the perforated pipe 24 (water supply member 16), and surplus water remaining inside the perforated pipe 24 without being supplied is discharged to the water storage tank 34. . That is, normally, the surplus water remaining inside the perforated pipe 24 without being supplied with water penetrates deeply underground from the downstream end of the water supply member 16, but according to this system 10, the perforated pipe 24 It is possible to store the excess water in the water storage tank 34.

  Further, in the system 10, the perforated pipe 24 is also used as the water collecting member 36. For this reason, when the water supplied excessively in the water-impervious member 12 or the water excessively given to the soil by natural rain or the like accumulates in the water-impervious member 12, the water collects in the perforated pipe 24. Water is discharged and discharged to the water storage tank 34 through the second water distribution pipe 32. That is, according to this system 10, it is possible to adjust the moisture content of the soil formation layer with the perforated pipe 24 and to store the excess water in the water shielding member 12 in the water storage tank 34.

  Therefore, for example, as shown in FIG. 7, the system 10 is provided with a pump 40 (for example, a solar circulation pump or the like) that sends the water stored in the water storage tank 34 to the water supply tank 30. Is returned to the water supply tank 30 of the same system 10, the water stored in the water storage tank 34 is transported to the water supply tank 30 by a tank truck or the like, or the water stored in the water storage tank 34 is stored. If the water is supplied to the water supply tank of another system applied to the cultivated land below the cultivated land 200, the surplus water stored in the water storage tank 34 can be reused.

  Thus, according to this system 10, wasteful use of water can be reduced and water resources can be used efficiently. In particular, in farm fields such as remote islands, it is possible to bring moisture to the plants to be cultivated while reducing the amount of seawater desalination by not letting rainwater escape, so the effect of using the system 10 is great.

  As another embodiment of the system 10, as shown in FIG. 8, the water supply hose 42 is inserted through the entire length of the perforated pipe 24 and discharged from the water supply hose 42 into the perforated pipe 24. The water may be supplied into the water shielding member 12 through each through hole 26 of the perforated pipe 24. For example, for the water supply hose 42, a so-called drip tube or the like in which the internal water oozes out of the wall surface by applying water pressure can be used. By doing so, it is possible to equalize the amount of water supplied from each through hole 26 of the perforated pipe 24 to the water retention member 14, and in turn, in the cultivated land 200 of the same system 10, the amount of water in the soil layer Can be kept more even.

  Although not shown, the water supply hose 42 may be disposed in the water shielding member 12 as the water supply member 16 instead of the perforated pipe 24 described above. In this case, the water supply member 16 does not function as a drain pipe.

  Furthermore, although not shown, the perforated pipe 24 described above is disposed as the drainage member 36 in the water shielding member 12, and the water supply hose 42 is disposed in the water shielding member 12 as the water supply member 16. It may be.

  Further, in the above-described embodiment, the water retaining member 14 is provided at the bottom of the water shielding member 12 and the perforated tube 24 is placed on the upper side of the water retaining member 14, but the perforated tube 24 is not necessarily connected to the water retaining member 14. There is no need to place it on the upper side of the.

  For example, as in still another embodiment of the system 10 shown in FIG. 9, all or part of the perforated tube 24 may be embedded in the water retaining member 14. In this case, the perforated pipe 24 mainly functions as a water supply pipe to the water retention member 14. Alternatively, the water-impervious member 12 may be filled with the water-retaining member 14, and the perforated tube 24 may be embedded in the water-retaining member 14. In short, as in the above-described embodiments, if the perforated pipe 24 (water supply member 16) is disposed with the water retention member 14 interposed between the bottom portion in the water shielding member 12 and the system, 10 can exhibit its effect.

  Furthermore, as in another embodiment of the system 10 shown in FIG. 10, a hook-shaped member 44 may be provided in the opening 22 on the upper side of the water shielding member 12. For example, the hook-shaped member 44 is formed of a material having a water-blocking property such as a synthetic resin and a metal, and extends outward from the upper end of the side plate 20 in a bowl shape so as to extend over the entire length of the water-blocking member 12, and below the soil Block water penetration into the water. As described above, the moisture of the water retaining member 14 is sucked up by the capillarity in the upper soil and permeates into the upper portion of the water shielding member 12 and the surrounding soil. If the member 44 is provided, the bowl-shaped member 44 blocks the penetration of water into the soil below it and reduces the amount of water penetrating downward, so that the permeated water is laterally or upwardly. It will penetrate in the direction. As a result, it is possible to form the soil portion 38 in the capillary water state that spreads widely in the lateral direction while reducing the amount of water to be used. Furthermore, when there is rain, rainwater that has penetrated into the ground can be guided into the water-impervious member 12 without penetrating the soil below by the hook-shaped member 44. That is, since rainwater can be collected efficiently by the water shielding member 12, water resources can be used more efficiently.

  Further, as in still another embodiment of the system 10 shown in FIG. 11, a plurality of partition portions 46 are formed at the bottom portion in the water shielding member 12, and the water retaining members 14 a are provided in the respective partitions partitioned by the partition portions 46. You may make it provide.

  The partition portion 46 is made of a material having water shielding properties such as synthetic resin and metal, and is formed to protrude upward from the upper surface of the bottom plate 18 of the water shielding member 12. The partition part 46 is arrange | positioned by the fixed space | interval in the installation (inclination) direction of the water-impervious member 12, and the space | interval of the adjacent partition parts 46 is suitably set according to the gradient of the cultivated land 200, for example, is 1000 mm, The height is set to the same level as the thickness of the water retaining member 14.

  The partition part 46 partitions the space inside the water-impervious member 12, and a water retaining member 14 a is provided at the bottom of each partition partitioned by the partition part 46. By doing so, the water supplied from the perforated pipe 24 and accumulated at the bottom of each section partitioned by the partition 46 is absorbed by the water retaining member 14a provided at the bottom of each section. Therefore, the amount of water absorbed by each of the water retaining members 14a can be kept substantially uniform. That is, in the cultivated land 200 of the same system 10, the water content of the soil layer can be kept more even.

  Instead of forming the partition 46 at the bottom of the water shielding member 12, a partition member 48 that deforms the bottom plate 18 of the water shielding member 12 may be embedded in the cultivated land 200.

  Specifically, as shown in FIG. 12, along the slope of the cultivated land 200, partition members 48 are embedded in the ground at regular intervals. For example, the partition member 48 is formed in a rectangular plate shape, and the length in the width direction is set to be approximately the same as the width of the opening 22 of the water shielding member 12, for example. Then, by embedding the water shielding member 12 on the upper side of the partition member 48, the shape of the bottom plate 18 of the water shielding member 12 is deformed along the outer shape of the partition member 48, thereby forming an uneven shape on the bottom plate 18. And the convex part which protrudes upwards among the uneven | corrugated shape is functioned as the partition part 46, and the water retention member 14a is each provided in each division partitioned by the convex part. By doing so, the water accumulated at the bottom of each section partitioned by the convex part is absorbed by the water retaining member 14a provided at the bottom of each section, so that each water retaining member 14a absorbs. It is possible to keep the water content almost even.

  Furthermore, in the above-described embodiment, the water retaining member 14 is supplied with water through the circular through holes 26 that are randomly distributed over the entire wall of the perforated tube 24. However, the present invention is not limited to this. As described above, the shape, size, formation position, number, and the like of the through holes 26 may be appropriately set in consideration of the amount of water supplied from the perforated tube 24 to the water retention member 14.

  For example, the through holes 26 may be formed near the tube bottom of the perforated tube 24 so as to be arranged at a predetermined interval in the tube axis direction. In this case, since the perforated pipe 24 mainly supplies the water inside thereof, the roots of the plant extending toward the water supply source enter the through hole 26 of the perforated pipe 24. There is no problem such that the through hole 26 is blocked.

  Furthermore, the through-hole 26 is not limited to the one that penetrates the tube wall of the perforated tube 24 in a straight line, and may be porous or mesh-shaped, or the through-hole 26 may be formed in a slit shape. Good.

  Moreover, in the above-mentioned Example, although the water storage tank 34 was connected to the downstream edge part of the perforated pipe 24 (water supply member 16) via the 2nd water distribution pipe 32, it does not need to be limited to this. For example, the downstream end of the perforated pipe 24 may be directly connected to the water storage tank 34. Further, the water storage means is not limited to the water storage tank 34, and a reservoir or the like may be formed on the downstream side of the water supply member 16 and used as the water storage means.

  Furthermore, it is not always necessary to provide a water storage means, and the water storage means is not necessary if the required amount of water is fed from the water supply tank 30 to the perforated pipe 24. Furthermore, the downstream end of the perforated pipe 24 is connected to a drain pipe, and the water blocking member 12 collects excess water in the perforated pipe 24 or collects water inside the perforated pipe 24 via the drain pipe. The excess water inside may be discharged to a sewage treatment facility or the like.

  Furthermore, in the above-described embodiment, the water supply tank 30 is connected to an agricultural water pipe or the like and stores water sent therefrom, but is not limited to this. For example, the water supply tank 30 is not necessarily provided, and water may be directly supplied to the water supply member 16 from an agricultural water distribution pipe or the like. In this case, the agricultural water distribution pipe becomes the water supply source. Moreover, a fertilizer and an agrochemical may be dissolved in the water supplied to the water supply member 16, and a fertilizer and an agrochemical may be administered to a crop with water.

  Furthermore, in the above-described embodiment, the water retaining member 14 made of a general water retention agent or a mixture of such a water retention agent and soil is provided at the bottom of the water shielding member 12, but the present invention is not limited thereto. There is no need to The material of the water retention member 14 is not particularly limited as long as it has water absorption and water retention.

  For example, when the cultivated land 200 is configured by soil having water retention capacity as in still another embodiment of the system 10 shown in FIG. 13, the soil of the cultivated land 200 ( Alternatively, the soil portion 50 in the capillary water state or the gravity water state formed on the bottom of the water-impervious member 12 is used as the water retaining member 14. May be.

  In this system 10, the water supplied from the perforated pipe 24 to the inside of the water shielding member 12 penetrates into the soil filled in the bottom of the water shielding member 12 and is retained in the soil. That is, when the water that has penetrated into the soil becomes capillary water or gravity water and remains inside the water shielding member 12, the soil portion 50 in the capillary water state or the gravity water state is formed at the bottom of the water shielding member 12. It is formed. And the capillary water and gravity water of the bottom part in the water-impervious member 12, ie, the water | moisture content of the soil part 50 are sucked up and permeate | transmitted to the upper soil by the capillary phenomenon, and the soil part of a capillary water state is carried out to the upper soil. 38 is formed.

  However, in the case where the cultivated land 200 is a so-called paddy field or sandy land having a weak water retention capacity, it is preferable to prepare a soil having a high water retention capacity in advance and fill the bottom of the water shielding member 12 with the soil. Moreover, the water filling power may be improved by making the soil filled in the water-impervious member 12 into a multi-layer state, such as forming a gravel layer, a sand layer, and a silt layer in order from the lower layer.

  Furthermore, in the above-described embodiment, the water retaining member 14 is provided over the entire length of the water shielding member 12 in the length direction, but it is not necessary to be limited to this. For example, the water retention member 14 may be provided only in a necessary place where irrigation is desired.

  Furthermore, in the above-described embodiment, the water-impervious members 12 formed in an elongated groove shape are regularly arranged along the ridges 202 of the cultivated land 200, but the present invention is not limited to this. May be irregularly arranged.

  Furthermore, it is not always necessary to install the water shielding member 12 so that the longitudinal direction thereof follows the inclination of the cultivated land 200. If the water-impervious member 12 is embedded in the ground of the cultivated land 200, the water-impervious member 12 may be disposed such that the longitudinal direction thereof deviates from the inclined direction of the cultivated land 200. 12 may be embedded with an inclination greater than or less than the gradient of the cultivated land 200.

  Moreover, although the water-impervious member 12 is basically arranged linearly, it may be arranged to meander. Furthermore, by disposing the water shielding member 12 over the entire cultivated land 200, the entire soil layer of the cultivated land 200 can be used as the soil portion 38 in the capillary water state. By disposing the water-impervious member 12 in the range, only a partial range of the soil layer of the cultivated land 200, that is, only a range desired by the farmer can be used as the soil portion 38 in the capillary water state.

  Furthermore, basically, the system 10 is preferably used when the water shielding member 12 is installed in the ground of the cultivated land 200 at a predetermined slope, but the system 10 is not limited to this and is not limited thereto. The system 10 may be applied when the water member 12 is installed horizontally or substantially horizontally in the cultivated land. Even in that case, when the water shielding member 12 is buried in the ground, the water shielding member 12 is accurately (strictly) leveled at the construction site with respect to some undulation (up and down) of the cultivated land 200. Therefore, the effect of using the system 10 is great.

  For example, in yet another embodiment of the system 10 shown in FIG. 14, the system 10 is applied to a cultivated land 200 that is erected in a direction perpendicular to the slope (eg, along a contour line), and the impermeable member 12 is cultivated. It is buried in the ground horizontally along the direction orthogonal to the inclination of the ground 200. Hereinafter, the same reference numerals are used for the same parts as in the previous embodiment, and the description thereof is omitted or simplified.

  As shown in FIG. 14, the water-impervious member 12 is formed in an elongated groove shape, and is embedded in the ground such that its longitudinal direction is along a direction perpendicular to the inclination of the cultivated land 200. And the water-impervious member 12 extending to the vicinity of both ends of the cultivated land 200 is arranged so as to be arranged at a predetermined interval in the inclination direction of the cultivated land 200. A water retaining member 14 is provided at the bottom of the water shielding member 12. The perforated pipe 24 (the water supply member 16 and the water collecting member 36) is impermeable to water through the water retaining member 14 (that is, with the water retaining member 14 interposed between the water retaining member 12 and the bottom of the water impermeable member 12). It is disposed in the member 12.

  In the section between the water-impervious members 12 arranged at a predetermined interval in the inclination direction of the cultivated land 200, the perforated pipes 24 arranged inside each of the water-impervious members 12 pass through the pipe wall. 26 and the 3rd water distribution pipe 54 in which a space | gap etc. are not formed.

  Further, the upstream end portion of the perforated pipe 24 disposed in the water shielding member 12 installed at the top of the cultivated land 200 is inclined more than the water shielding member 12 through the first water distribution pipe 28. It is connected to a water supply tank 30 installed on the upper ground. Further, the downstream end portion of the perforated pipe 24 disposed in the water shielding member 12 installed at the lowermost part of the cultivated land 200 is inclined more than the water shielding member 12 through the second water distribution pipe 32. It is connected to a water storage tank 34 installed on the lower ground.

  In the embodiment of FIG. 14 as well, the water supplied into the water shielding member 12 is absorbed by the water retaining member 14 and the water (moisture) retained by the water retaining member 14 is soiled by capillary action as in the embodiment of FIG. Therefore, the amount of water retained in each water shielding member 12 can be kept substantially even without using special equipment such as a water level controller. Therefore, equipment costs, maintenance costs, etc. can be reduced.

  Furthermore, even when there are some undulations in the direction perpendicular to the slope of the inclined land, it is necessary to accurately level the water shielding member 12 at the construction site when the water shielding member 12 is buried in the ground. Therefore, the workability of the system 10 is improved.

  Also in this system 10, the excess water remaining in the perforated pipe 24 without being supplied with water or the surplus water in the water shielding member 12 collected by the perforated pipe 24 is stored in the water storage tank 34. Therefore, waste of water can be reduced and water resources can be used efficiently.

  Furthermore, the system 10 is applied not only to the cultivated land 200 erected in the direction orthogonal to the slope, but also to the cultivated land 200 in flat areas such as terraced fields and terraced rice fields formed on the sloped land. Is possible.

  For example, in still another embodiment of the system 10 shown in FIG. 15, the water shielding member 12 is embedded in the ground horizontally along the cultivated land 200 of the flat land portion of the terraced field. Hereinafter, the same reference numerals are used for the same parts as in the previous embodiment, and the description thereof is omitted or simplified.

  As shown in FIG. 15, the water-impervious member 12 is formed in an elongated groove shape, and is embedded in the ground so that its longitudinal direction follows the cultivated land 200 of the flat land portion of the terraced field. And the water-impervious members 12 extending to the vicinity of both ends of the cultivated land 200 are arranged so as to be arranged at a predetermined interval. A water retaining member 14 is provided at the bottom of the water shielding member 12, and the water retaining member 14 is provided via the water retaining member 14 (that is, with the water retaining member 14 interposed between the water shielding member 12 and the bottom). The hole tube 24 (the water supply member 16 and the water collecting member 36) is disposed in the water shielding member 12.

  The upstream end of the perforated pipe 24 is connected to the water supply tank 30 installed on the ground of the cultivated land 200 via the first water distribution pipe 28. Further, the downstream end portion of the perforated pipe 24 is connected to a water storage tank 34 installed in a flat land portion below the cultivated land 200 via the second water distribution pipe 32. The second water distribution pipe 32 has a slight downward slope from the downstream end of the perforated pipe 24 toward the water storage tank 34 so that the flow of water from the perforated pipe 24 to the water storage tank 34 is smooth. So that it is piped.

  In the embodiment of FIG. 15 as well, in the same manner as in the embodiment of FIG. 1, the water supplied into the water-impervious member 12 is absorbed by the water-retaining member 14, and the water (water) retained by the water-retaining member 14 is soiled by capillary action. Therefore, the amount of water retained in each water shielding member 12 can be kept substantially even without using special equipment such as a water level controller. Therefore, equipment costs, maintenance costs, etc. can be reduced.

  Furthermore, even when the cultivated land 200 in the flat land portion of the terraced field has some undulations, when the water shielding member 12 is buried in the ground, the water shielding member 12 is accurately leveled at the construction site. Since it is not necessary, the workability of the system 10 is improved.

  Also in this system 10, the excess water remaining in the perforated pipe 24 without being supplied with water or the surplus water in the water shielding member 12 collected by the perforated pipe 24 is stored in the water storage tank 34. Therefore, waste of water can be reduced and water resources can be used efficiently.

  In each of the above-described embodiments, the elongate groove-shaped water shielding member 12 in which the side plate 20 rises slightly outward from both side ends of the bottom plate 18 is illustrated, but it is not necessary to be limited to this. As long as the water shielding member 12 is formed in a container shape having an upper opening and has a water storage function, an appropriate shape can be applied.

  For example, if the width of the opening on the upper side (top end) of the water-impervious member 12 is increased, the water excessively applied to the soil is easily accumulated in the water-impervious member 12. That is, since the water collecting capacity of the water shielding member 12 can be increased, water resources can be used more efficiently. Further, the material of the water shielding member 12 is not necessarily limited to synthetic resin or metal, and any appropriate material can be applied as long as it is a material having water shielding properties.

  In still another embodiment of the system 10 shown in FIGS. 16 and 17, the water shielding member 12 is formed using a water shielding sheet 56 formed of rubber, synthetic resin, or the like. Hereinafter, the same reference numerals are used for the same parts as in the previous embodiment, and the description thereof is omitted or simplified.

  As shown in FIGS. 16 and 17, in this system 10, the water shielding sheet 56 is laid under the cultivated land 200 so as to spread over the entire surface along the inclined cultivated land 200. The water-impervious sheet 56 is curved into a wave shape (or a zigzag shape) so as to repeat unevenness in a direction orthogonal to the inclination of the cultivated land 200. That is, the water shielding sheet 56 is formed with recesses 58 extending along the inclination direction of the cultivated land 200 so as to be arranged at a predetermined interval. In the system 10, each of the recesses 58 functions as the water shielding member 12. The water retaining member 14 is provided at the bottom of the recess 58, and the perforated pipe 24 (the water supply member 16 and the water collecting member 36) is disposed in the water shielding member 12 through the water retaining member 14. The upstream end of the perforated pipe 24 is connected to the water supply tank 30 via the first water distribution pipe 28. The downstream end of the perforated pipe 24 is connected to the water storage tank 34 via the second water distribution pipe 32.

  When such a system 10 is formed on the cultivated land 200, as shown in FIG. 18 (a), first, the ground of the cultivated land 200 is excavated and the bottom thereof is perpendicular to the inclination of the cultivated land 200. Repeated uneven portions 60 are formed. And as shown in FIG.18 (b), the water-impervious sheet | seat 56 is laid on the upper side of the uneven | corrugated | grooved part 60. FIG. Then, since the water-impervious sheet 56 is curved in a wave shape in accordance with the shape of the concavo-convex part 58 and the concave part 58 is formed in the water-impervious sheet 56, the water retaining member 14 is provided at the bottom of the concave part 58. A perforated tube 24 is disposed on the upper side. Then backfill the excavated ground.

  Also in this system 10, the water supplied into the recess 58 is absorbed by the water retaining member 14, and the water retained by the water retaining member 14 is supplied to the soil by capillary action. The water content of the soil layer can be kept as uniform as possible. Moreover, since there is no need to use special equipment such as a water level management device, equipment costs and maintenance costs can be reduced.

  Furthermore, since the surplus water remaining inside the perforated pipe 24 without being able to supply water and the surplus water in the water shielding member 12 collected by the perforated pipe 24 can be stored in the water storage tank 34, water Waste water can be reduced, and water resources can be used efficiently.

  The water shielding sheet 56 is not necessarily provided on the entire surface of the cultivated land 200, and can be formed in a part of the cultivated land 200, or can be distributed and arranged in the ground of the cultivated land 200. Moreover, you may make it arrange | position the water-impervious sheet | seat 56 for every ridge 202 of the cultivated land 200 similarly to the Example of FIG.

  In addition, it is not always necessary to form the recessed portions 58 in the water shielding sheet 56 over the entire length in the direction orthogonal to the inclination of the cultivated land 200, and a plurality of recessed portions 58 can be formed in a part of the water shielding sheet 56. That is, the recessed portion 58 of the water shielding sheet 56 may be provided at a necessary place where irrigation is desired, and the water shielding sheet 56 is not formed with the recessed portion 58 in addition to the wave-shaped portion where the recessed portion 58 is formed. You may have a planar part. Further, it is not always necessary to form the recess 58 extending along the inclination direction of the cultivated land 200.

  Furthermore, in each of the above-described embodiments, the perforated tube 24 is disposed in the central portion of the bottom portion in the water shielding member 12, that is, the central portion in the width direction of the bottom plate 18, but it is necessary to be limited to this. There is no. As in still another embodiment of the system 10 shown in FIG. 19, the perforated tube 24 may be disposed so as to contact the side plate 20 at the end in the width direction of the bottom plate 18. By doing so, the perforated tube 24 is less likely to be displaced in the vertical direction or the left-right direction during construction of the system 10, and the perforated tube 24 can be positioned easily and reliably.

  In particular, in the cultivated land 200 constituted by soil having water retaining ability, the soil portion 50 formed on the bottom portion in the water shielding member 12 is filled with the soil in the cultivated land 200 in the bottom portion in the water shielding member 12 and the water retaining member 14. When the system 10 to be used is constructed, the workability can be improved by arranging the perforated tube 24 so as to be in contact with the side plate 20 at the end in the width direction of the bottom plate 18.

  Specifically, the applicant of the present application described in Japanese Patent Application No. 2012-037794, filed on February 23, 2012, for an underground irrigation member (water shielding member) for constructing an underground irrigation system on cultivated land. 12, the water supply member 16) is proposed, but when the system 10 is constructed using such a laying device 200, the workability can be improved.

  Below, with reference to FIG. 20 and FIG. 21, the method of constructing the system 10 using the laying apparatus 200 will be briefly described. The construction method of the system 10 using such a laying apparatus 200 is described below. As described in detail in the aforementioned Japanese Patent Application No. 2012-037794, refer to this patent document if necessary.

  First, the ground at one end of the formation section of the system 10 in the cultivated land 200 is excavated to provide a stand (not shown) on the cultivated land 200, and the main body portion 206 of the laying device 204 is disposed in the stand. .

  Next, the synthetic resin sheet 210 (water-impervious member 12) pulled out from the first roll portion 208 of the laying device 200 is molded into a groove shape and fixed in the standing wall, and the second side is placed above the synthetic resin sheet 210. A flexible tube 214 (perforated tube 24) drawn from the roll unit 212 is disposed.

  Then, in a state where the distal end portion of the synthetic resin sheet 210 and the distal end portion of the flexible tube 214 are fixed within the stand, the laying device 204 is advanced by pulling with a working machine such as a backhoe, so that the main body is removed from the stand. The portion 206 is driven (inserted) into the ground of the cultivated land 200, and the main body portion 206 is moved in the pulling direction in the ground.

  Then, as shown to Fig.21 (a), the soil of the cultivation land 200 is divided | segmented up and down by the main-body part 206, and the space | gap 216 is formed in the ground. Then, the dug up (cultivated) soil enters the inside of the main body portion 16 and is temporarily lifted, and as shown in FIG. 21B, the synthetic resin pulled out from the first roll portion 204 so as to be sandwiched between the gaps 216. Sheets 210 are continuously laid. Then, the flexible pipe 214 drawn out from the second roll part 212 is continuously disposed on the upper side of the synthetic resin sheet 210 while the dug up soil is backfilled on the upper side of the synthetic resin sheet 210. At this time, since the flexible tube 214 is disposed at the end in the width direction of the bottom plate 18 of the water shielding member 12, the backfilled soil interferes with the flexible tube 214 when the dug up soil is backfilled. Can be avoided as much as possible.

  By performing this until reaching the ground at the other end of the formation section of the system 10 of the cultivated land 200, the water shielding member 12 and the perforated pipe 24 are embedded in the ground of the cultivated land 200.

  As described above, if the perforated pipe 24 is disposed at the end in the width direction of the bottom plate 18 of the water shielding member 12, the bottom of the water shielding member 12 is filled with the soil of the cultivated land 200, and the water shielding member When constructing the system 10 that uses the soil portion 50 formed at the bottom in the water 12 as the water retaining member 14, the perforated tube 24 is less likely to interfere with the soil to be backfilled. Therefore, for example, a large soil block or the like can easily enter below the perforated pipe 24, so that the soil can be backfilled in the bottom portion in the water shielding member 12 appropriately and reliably.

  Further, in each of the above-described embodiments, the perforated pipe 24 (the water supply member 16 and the water collecting member 36) is placed on the upper side along the water retaining member 14, or all or part of the perforated pipe 24 is disposed. However, the present invention is not limited to this, and the perforated tube 24 may be installed separately from the water retention member 14. Even in this case, as described above, the perforated pipe 24 with the water retaining member 14 interposed in the water shielding member 12 via the water retaining member 14, that is, between the bottom portion in the water shielding member 12. If the system 10 is arranged, the system 10 can exert its effect.

  For example, in still another embodiment of the system 10 shown in FIG. 22, the bottom of the water shielding member 12 has a step higher than the lowest first position h1 and is higher than the second position h2. The hole tube 24 is placed.

  As shown in FIG. 22, the water-impervious member 12 is formed in an elongated groove shape in which the side plate 20 rises slightly outward from both ends of the bottom plate 18, and its longitudinal direction follows the inclination of the cultivated land 200. Buried inside. One of the side plates 20 is bent outward at a predetermined height to form a flat second bottom plate 60 there. The second bottom plate 60 is formed at a second position (height) h <b> 2 that is higher than the bottom plate 18 at the lowest first position (height) h <b> 1 in the bottom portion in the water shielding member 12. The perforated tube 24 is placed on the upper side along the second bottom plate 60.

  Further, for example, in this system 10, the bottom of the water-impervious member 12 is filled with soil of the cultivated land 200, and the soil part 50 formed at the bottom of the water-impervious member 12 is used as the water retaining member 14. The thickness (length in the vertical direction) of the soil portion 50, that is, the water retaining member 14, is set to be substantially the same as or lower than the height from the first position h1 to the second position h2.

  Here, when constructing such a system 10 using the laying device 204 described above, the soil of the cultivated land 200 is divided by the main body portion 206, as shown in FIG. A flat portion 218 on which the bottom plate 18 of the water shielding member 12 is placed on the upper side is formed on the lower soil of the gap 216 (that is, the soil not dug up by the main body portion 206), and the first flat surface thereof. A second flat surface portion 220 on which the second bottom plate 60 is placed on the upper side is formed at a position higher than the portion 218 by a predetermined height (a difference in height between the second position h2 and the first position h1). It will be. Then, as shown in FIG. 23 (b), the water shielding member 12 is laid so as to be sandwiched between the gaps 216, and the dug up soil is backfilled above the water shielding member 12, and the second water shielding member 12 is inserted. The perforated tube 24 is disposed above the bottom plate 60.

  As described above, in the system 10 shown in FIG. 22, the second bottom plate 60 is formed at the second position h2 higher than the lowest first position h1 of the water shielding member 12, and the second bottom plate 60 is provided above the second bottom plate 60. Since the perforated tube 24 is placed, the perforated tube 24 can be placed on the upper side of hard soil that is not dug up (not cultivated) with the water shielding member 12 interposed therebetween.

  Here, when the perforated pipe 24 is disposed on the soil once cultivated, the soil is softened by cultivating the soil, so that the soil under the perforated pipe 24 is reduced by the weight of the perforated pipe 24 or the soil. That is, there is a concern that the perforated tube 24 may move downward by compressing and crushing the soil of the soil portion 50. That is, since the position of the perforated pipe 24 in the vertical direction is not stable, the distance between the bottom of the water shielding member 12 and the perforated pipe 24 becomes non-uniform, and thus the amount of water retained in the soil part 50 Will be uneven.

  On the other hand, as in this embodiment, the perforated pipe 24 is positioned in the vertical direction by placing the perforated pipe 24 on the soil that is not cultivated with the water shielding member 12 interposed therebetween. By doing so, the vertical position of the perforated pipe 24 can be stabilized, so that the distance between the bottom of the water shielding member 12 and the perforated pipe 24 is made uniform from the upper end of the water shielding member 12 to the lower end of the inclination. Thus, the amount of water to be retained in the soil portion 50 can also be made uniform. Therefore, the moisture content of the soil portion 38 in the capillary water state is not biased, and the moisture content of the soil layer can be kept more even.

  Further, according to this embodiment, the perforated tube 24 can be easily and reliably positioned when the system 10 is constructed.

  In addition, although the case where the system 10 was constructed using the laying device 200 has been described above, the present invention is not limited to this, and the ground is dug up by an excavating machine such as a trencher, and the water-impervious member 12 and the presence of the impermeable member 12 are provided. The same applies when the soil is backfilled after the hole tube 24 is installed.

  In the embodiment of FIG. 22, one side plate 20 of the two side plates 20 of the water shielding member 12 is bent outward at a predetermined height to form a second bottom plate 60, and the second bottom plate 60 is formed. Although the perforated tube 24 is placed on the top, it need not be limited to this. If the portion (second bottom plate 60) on which the perforated tube 24 can be placed is formed on the upper side at the second position h2 which is higher than the first position h1 of the bottom plate 18, the water shielding member 12 is formed. The shape is not particularly limited. For example, as shown in FIG. 24, the central portion in the width direction of the bottom plate 18 is raised in a step shape to form a second bottom plate 60 there, and the perforated tube 24 is formed on the second bottom plate 60. You may make it mount.

  By the way, in each of the above-described embodiments, the water supplied into the water-impervious member 12 is absorbed by the water retaining member 14, and the water retained by the water retaining member 14 is supplied to the soil by capillary action. Even if the water-impervious member 12 is inclined and embedded, the water content of the soil portion 32 in the capillary water state is not biased, and even without using special equipment such as a water level controller, the water-impervious member 12 is used. The amount of water retained inside could be kept almost even.

  However, the same amount of water as the water accumulated at the bottom in the water shielding member 12 on the inclined upper end side (that is, the upstream side of the perforated pipe 24) is on the inclined lower end side (that is, the downstream side of the perforated pipe 24). Since a time difference will inevitably occur before the bottom of the water shielding member 12 accumulates, even if the soil portion 50 contains a sufficient amount of water on the inclined upper end side of the water shielding member 12, the inclined lower end side of the water shielding member 12 Then, the situation that the amount of water contained in the soil part 50 is insufficient may occur.

  In particular, when the cultivated land 200 is composed of, for example, highly viscous (clayy) soil, the soil portion 50 formed at the bottom of the water-impervious member 12 is used as the water retaining member 14. Due to the nature of the soil, the rate at which the water supplied from the perforated pipe 24 into the water shielding member 12 penetrates into the soil is reduced, so that the inclined upper end side and the inclined lower end side of the water shielding member 12 are reduced. The difference in water volume becomes significant.

  Therefore, in still another embodiment of the system 10 shown in FIG. 25, the water level detection means 62 that detects the water level of the gravitational water in the soil part 50 is installed at the inclined lower end of the water shielding member 12, and the water level detection means 62 By controlling the water supply from the water supply member 16 to the water retention member 14 by the water supply control means 64 based on the detection result, the amount of water contained in the soil portion 50 on the inclined upper end side and the inclined lower end side of the water shielding member 12, that is, soil The water level of the gravity water in the section 50 is made uniform.

  As shown in FIG. 25, the water-impervious member 12 is formed in an elongated groove shape in which the side plate 20 rises slightly outward from both side ends of the bottom plate 18, and its longitudinal direction follows the inclination of the cultivated land 200. Buried inside. And the water-impervious members 12 extending to the vicinity of both ends of the cultivated land 200 are arranged so as to be arranged at a predetermined interval.

  For example, in this embodiment, the bottom of the water-impervious member 12 is filled with soil of the cultivated land 200, and the soil portion 50 formed therein is used as the water retention member 14. In addition, the perforated pipe 24 (the water supply member 16 and the water collecting member 36) is disposed in the water shielding member 12 through the water retaining member 14.

  The downstream end of the perforated pipe 24 is connected to the second water distribution pipe 32 via a water level detecting means 62 described later in detail, and the downstream end of the second water distribution pipe 32 is connected to the water storage tank 34. The Further, the upstream end portion of the perforated pipe 24 is connected to the water supply tank 30 installed on the ground of the cultivated land 200 via the first water distribution pipe 28, and the connection between the first water distribution pipe 28 and the water supply tank 30 is performed. The unit is provided with water supply control means 64 that operates based on the detection result of the water level detection means 62.

  As shown in FIG. 26, the water level detection means 62 includes a vertical pipe member 66 and a water level detector 68 and is embedded in the cultivated land 200 so as to be adjacent to the inclined lower end of the water shielding member 12.

  The vertical tube member 66 is made of a synthetic resin such as vinyl chloride, and is formed in a bottomed cylindrical shape in which a bottom plate 66b is provided at the lower end of a side wall 66a that rises in the vertical direction, and the bottom plate 66b is an inclined lower end of the water shielding member 12. It arrange | positions so that it may become a position (height) lower than the baseplate 18. FIG. An inflow port 70 that communicates with the inclined lower end of the water shielding member 12 is formed in the side wall 66a. The inflow port 70 is a substantially trapezoidal opening corresponding to the water shielding member 12, and the inclined lower end of the water shielding member 12 is inserted into (joined to) the inflow port 70. For this reason, the water level inside the vertical pipe member 66 is interlocked with the level of gravity water in the soil part 50 at the inclined lower end of the water shielding member 12.

  In addition, a filter 72 is provided outside the perforated pipe 24 and inside the water shielding member 12 at the joint between the water shielding member 12 and the vertical tube member 66. Mud or the like inside the member 12 is prevented from entering the inside of the vertical tube member 66.

  Further, on the side wall 66a of the vertical pipe member 66, the outflow port 74 is located at a position corresponding to the set water level W of the soil portion 50 at the lower end of the inclined side of the water shielding member 12 (appropriate water level of the gravitational water of the soil portion 50). Is formed. For example, in this embodiment, the set water level W of the gravitational water in the soil portion 50 is set to be equal to the height position of the tube bottom of the perforated tube 24 disposed in the water shielding member 12. The outlet 74 is disposed at a position where the height of the lower end of the outlet 74 becomes equal to the set water level W of the gravity water of the soil part 50. However, it is not necessary to be limited to this. The second water distribution pipe 32 is connected to the outflow port 74, and the downstream end of the second water distribution pipe 32 is connected to the water storage tank 34.

  Further, the water level detector 68 detects the water level of the gravitational water in the soil portion 50 at the lower end of the inclined side of the water shielding member 12, that is, the water level inside the vertical pipe member 66 in conjunction therewith. For example, in this embodiment, the water level detector 68 has a general-purpose water level adjustment variable ball tap 68a, and the ball tap 68a detects whether the water level inside the vertical tube member 66 is higher or lower than the set water level W. To do. When the water level inside the vertical pipe member 66 becomes higher than the set water level W, a control signal such as a pilot pressure or an electric signal is transmitted to the water supply control means 64.

  Returning to FIG. 25, the water supply control means 64 is a pilot valve, an electromagnetic valve or the like provided between the water supply tank 30 and the first water distribution pipe 28, and the water level inside the vertical pipe member 66 is higher than the set water level W. When a control signal indicating that the value has become higher is transmitted from the water level detector 68, water supply from the water supply tank 30 to the first water distribution pipe 28 is stopped based on the control signal.

  As for the timing of the start of water supply from the water supply tank 30 to the first water distribution pipe 28, the water is automatically supplied from the water supply tank 30 in a predetermined time zone using a timer or the like, as in the above-described embodiments. Or supply the water by monitoring the physiological condition of the cultivated crop. However, instead of this, when the water level inside the vertical pipe member 66 becomes lower than the set water level W, water supply from the water supply tank 30 to the first water distribution pipe 28 is automatically started, and the vertical pipe member When the water level inside 66 becomes higher than the set water level W, the water supply from the water supply tank 30 to the first water distribution pipe 28 may be automatically stopped.

  In such a system 10, during irrigation, the water supplied from the perforated pipe 24 into the water shielding member 12 gradually moves from the upstream side of the perforated pipe 24 toward the downstream side within the water shielding member 12. 50 is absorbed. And if the water which the perforated pipe | tube 24 supplied to the soil part 50 is absorbed by the soil part 50 in the inclination lower end of the water-impervious member 12, the water level detection means 62 will detect the water level of the soil part 50, and the water level will be detected. When the water level is higher than the set water level W, water supply from the water supply tank 30 to the first water distribution pipe 28 is stopped.

  That is, in the embodiment of FIG. 25, the water supply to the perforated pipe 24 is controlled based on the level of gravity water in the soil portion 50 at the inclined lower end of the water shielding member 12, so that the viscosity is very high temporarily. Even when the cultivated land 200 is constituted by soil, the amount of water contained in the soil portion 50 on the inclined lower end side of the water shielding member 12 does not become insufficient. Therefore, the water level of the gravitational water in the soil portion 50 can be made uniform from the upper slope end to the lower slope end of the water shielding member 12.

  Furthermore, after the water supply is started, when the water supplied from the perforated pipe 24 is supplied to the entire soil portion 50 from the upper end of the water shielding member 12 to the lower end of the inclination, that is, the soil portion 50 at the lower end of the water shielding member 12 is inclined. Since the water supply from the water supply tank 30 to the first water distribution pipe 28 is stopped when the water level of the gravitational water becomes higher than the set water level W, it is possible to prevent an excess or deficiency of the water supply amount. And since excessive water supply or the wasteful discharge | release of the water downstream from the system 10 can be prevented, water resources are not wasted.

  Note that it is not always necessary to provide the water supply control means 64 between the water supply tank 30 and the first water distribution pipe 28, and in the middle of the flow path of the first water distribution pipe 28 or between the first water distribution pipe 28 and the perforated pipe 24. You may make it provide the water supply control means 64 in a connection part. In short, it is only necessary to control the water supply from the perforated pipe 24 into the water shielding member 12 based on the detection result of the water level detection means 62.

  Further, since mud mixed with water accumulates at the bottom of the vertical pipe member 66, the water level in the vertical pipe member 66 is not synchronized with the gravity water level of the soil part 50 at the inclined lower end of the water shielding member 12. In order to prevent this, mud discharge means may be provided at the bottom of the vertical pipe member 66, and mud collected at the bottom of the vertical pipe member 66 may be periodically discharged by the mud discharge means.

  As an example of such a mud discharging means, as shown in FIG. 27, a plate member 76 that can be moved up and down or removed can be installed at the bottom of the vertical tube member 66. For example, the plate member 76 has an upper end equal to the set water level W, that is, the height position of the tube bottom of the perforated tube 24 at the inclined lower end of the water shielding member 12, and is provided below the outlet 74. Then, if necessary, the plate member 76 is moved up or removed to allow the bottom of the vertical pipe member 66 and the second water distribution pipe 32 to communicate with each other, so that the mud accumulated at the bottom of the vertical pipe member 66 is second. Discharge to the water distribution pipe 32.

  Furthermore, in the embodiment of FIG. 25, the system 10 provided with the water level detection means and the water supply control means is applied to the cultivated land 200 having an inclination, and the water shielding member 12 is inclined and installed in the cultivated land 200. However, the present invention is not limited to this. The system 10 provided with the water level detection means and the water supply control means is applied to a cultivated land 200 that is set up in a direction orthogonal to the slope, or a flat cultivated land 200 such as terraced fields and terraced rice fields formed on the sloped land. The water shielding member 12 may be installed horizontally or substantially horizontally in the ground 200. By doing so, when the water shielding member 12 is buried in the ground, it is not necessary to accurately level the water shielding member 12 at the construction site, and workability is improved. However, in this case, the above-mentioned “inclined upper end side of the water shielding member 12” is set as “upstream end side of the perforated tube 24”, and “inclined lower end side of the water shielding member 12” is “perforated tube 24” The system 10 is constructed on the “downstream end side”.

  Furthermore, the system 10 is applied to a cultivated land 200 erected in a direction perpendicular to the slope, or a flat cultivated land 200 such as terraced fields and terraced rice fields formed on the sloped land to block the cultivated land 200 in the ground. When the water member 12 is installed horizontally or substantially horizontally, it is not always necessary to install the water level detecting means at the inclined lower end of the water shielding member 12, and both the water level detecting means and the water supply control means are both inclined upper ends of the water shielding member 12. You may make it provide in.

  For example, in still another embodiment of the system 10 shown in FIG. 28, the water shielding member 12 is formed in an elongated groove shape in which the side plate 20 rises slightly outward from both side ends of the bottom plate 18, and its longitudinal length. It is buried in the cultivated land 200 such that the direction is horizontal or substantially horizontal. And the water-impervious members 12 extending to the vicinity of both ends of the cultivated land 200 are arranged so as to be arranged at a predetermined interval.

  For example, in this embodiment, the bottom of the water-impervious member 12 is filled with soil of the cultivated land 200, and the soil portion 50 formed therein is used as the water retention member 14. In addition, the perforated pipe 24 (the water supply member 16 and the water collecting member 36) is disposed in the water shielding member 12 through the water retaining member 14.

  The downstream end of the perforated pipe 24 is connected to the second water distribution pipe 32, and the second water distribution pipe 32 is connected to the water storage tank 34. Further, as shown in FIG. 29, a vertical pipe member 78 is joined to the upstream end portion of the perforated pipe 24, and a water level management device 80 is installed inside the vertical pipe member 78.

  The vertical pipe member 78 includes a branch joint 82 and a rising pipe 84, and is buried in the ground. The branch joint 82 is made of a synthetic resin such as vinyl chloride and is formed in a cheese shape in which a receiving port 86 is formed in three directions. The receiving ports 86a and 86b whose axes coincide with each other, and the axis is the receiving port. There is a receiving port 86c orthogonal to the axes of 86a and 86b. The receiving port 86a of the branch joint 82 is provided with a lid 88 that seals the receiving port 86a, and the perforated tube 24 is connected to the receiving port 86b through a socket (increase) 90 having a different diameter. Is done. Note that a lid body is provided outside the perforated pipe 24 and inside the water-impervious member 12 at the junction between the socket 90 having a different diameter and the perforated pipe 24, and the perforated pipe is provided by this lid body. It is prevented that the water supplied from 24 into the water shielding member 12 is spilled outside the water shielding member 12.

  Further, the rising pipe 84 is connected to the receiving port 86 c of the branch joint 82. The riser tube 84 is formed in a cylindrical shape with openings at both ends by a synthetic resin such as vinyl chloride, and rises from the branch joint 82 to the ground surface. Above the upper end opening of the rising pipe 84, an end portion of a first water supply pipe 92 connected to the water supply tank 30 is disposed. The first water supply pipe 92 is mainly formed in the water shielding member 12 first in the soil portion 50. It is used when a large amount of water is supplied into the water-impervious member 12, such as when forming the water. In addition, a second water supply pipe 94 connected to the water supply tank 30 is inserted into the rising pipe 84, and the second water supply pipe 94 mainly controls the water level of the soil portion 50 formed in the water shielding member 12. Used when doing.

  Moreover, the water level management device 80 functions as a water level detection means and a water supply control means, detects the water level of the gravitational water in the soil portion 50 inside the water shielding member 12, and determines the water shielding member 12 according to the detection result. It controls the water supply to the inside. Such a simple water level controller 80 is described in detail in Japanese Patent Application Laid-Open No. 2010-029072 previously filed by the applicant of the present application and so on, so refer to this patent document if necessary.

  The water level manager 80 will be briefly described. The water level manager 80 includes a vertical pipe 96 and adjusts the supply of water according to the water level in the vertical pipe 96. The vertical tube 96 is formed in a cylindrical shape with openings at both ends by a synthetic resin such as vinyl chloride, and is erected at the bottom of the vertical tube member 78. An opening 98 is formed at the bottom of the side wall of the vertical pipe member 78 and the vertical pipe 96. The opening 98 serves as an inlet / outlet through which water in the vertical pipe 96 flows in and out.

  Further, a water level setting tool 100 and a float 102 are provided inside the vertical pipe 96. As shown in FIG. 30, the water level setting tool 100 is arranged in the vertical pipe 96 and defines the water level setting value in the vertical pipe 96 based on the arrangement height. It is fixed to the position (height) of the set water level of the gravity water of the part 50. That is, as will be described in detail later, when the water level in the vertical pipe 96 becomes the set water level of gravity water, the float 102 rises and comes into contact with the end of the upper surface 102a of the second water supply pipe 94, and the water supply port The water level setting tool 100 is fixed at such a position that 106 is closed. The water level setting tool 100 is formed in a bottomed cylindrical shape, and its outer diameter is set to be substantially the same as the inner diameter of the vertical tube 96 to such an extent that it can be placed at a desired position (height) in the vertical tube 96. . A through hole 104 is formed on the bottom surface of the water level setting tool 100.

  Further, the end of the second water supply pipe 94 described above is inserted into the upper end opening of the vertical pipe 96, and the second water supply pipe 94 is further inserted into the through hole 104 of the water level setting tool 100, so that the water level setting tool 100 is inserted. It is fixed so as to protrude downward. The end of the second water supply pipe 94 functions as a valve seat that comes into contact with an upper surface 102 a of the float 102 described later, and the opening serves as a water supply port 106 for supplying water into the vertical pipe 96.

  The float 102 is formed in a hollow cylindrical shape using an elastic material such as rubber and a synthetic resin, and is disposed below the water level setting tool 100. The float 102 rises and falls according to the fluctuation of the water level in the vertical pipe 96, and its upper surface 102a. Also functions as a valve body that contacts the valve seat and closes the water supply port 106. However, on the upper surface 102a of the float 102, at least the portion that contacts the valve seat is such that the upper surface 102a (valve element) of the float 102 and the end of the second water supply pipe 94 (valve seat) even when the ascending force of the float 102 is weak. It is preferable to form the elastic member such as rubber so that the water supply port 106 can be closed properly without any gap.

  In such a system 10, after construction of the system 10, water is supplied from the first water supply pipe 92 to the inside of the vertical pipe member 78, and water is supplied from the vertical pipe member 78 to the perforated pipe 24. The water supplied to the perforated pipe 24 penetrates through the soil and becomes gravity water and stays in the water shielding member 12. Thereby, the soil part 50 of the gravity water state is formed in the water-impervious member 12.

  And if the soil part 50 is formed over the full length of the bottom part in the water-impervious member 12, the water supply from the 1st water supply pipe | tube 92 will be stopped, Then, the gravity water of the soil part 50 will be stopped by the water level management device 80. Manage the water level. Specifically, as shown in FIG. 30A, the water flowing through the second water supply pipe 94 flows into the vertical pipe 96. Then, the water flowing into the vertical tube 96 flows out of the vertical tube 96 through the opening 98, that is, into the vertical tube member 78, and the water is supplied from the vertical tube member 78 to the perforated tube 24. .

  That is, the water level W of the gravitational water in the soil portion 50 of the water-impervious member 12 and the water level in the vertical tube 96 are interlocked, and when the water level of the gravitational water in the soil portion 50 reaches the set water level, FIG. As shown, the water supply port 106 is closed, and water supply from the second water supply pipe 94 into the vertical pipe 96 is stopped. Moreover, when the gravity water of the soil part 50 is sucked up by the upper soil and the water level of the gravity water is lower than the set water level, the water supply port 106 is opened as shown in FIG. Water is supplied from the pipe 94 into the vertical pipe 96.

  In the system of FIG. 28, the vertical pipe member 78 is installed outside the water-impervious member 12, and the water level manager 80 is installed therein. However, the present invention is not limited to this, and the water-impervious member The water level management device 80 may be directly installed inside 12.

  Further, it is not always necessary to use the water level manager 80 as described above, and the water level adjustment variable ball tap and pilot valve used in the embodiment of FIG. 25 may be used as the water level manager. In short, any water level management means including a water level detection means and a water supply control means can be applied.

  Furthermore, in the example of FIG. 25 and the example of FIG. 28, the bottom of the water-impervious member 12 is filled with the soil of the cultivated land 200, and the soil part 50 formed therein is used as the water retaining member 14. And although the water level detection means detected the water level of the gravity water of the soil part 50, it does not need to be limited to this, The water retention member 14 mixes a general purpose water retention agent, such a water retention agent, and soil. The water level held by the water retaining member 14 may be detected.

  In each of the above-described embodiments, the perforated pipe 24 is also used as a water collecting member 36 for collecting surplus water, and surplus water in the water shielding member 12 collected by the perforated pipe 24 is used as the first. In addition to discharging the water to the water storage tank 34 via the two water distribution pipes 32, a hydrophobic portion 108 is formed on the perforated pipe 24, and the hydrophobic section 108 and the perforated pipe 24 are connected to the water collecting member 36. It may be made to function as.

  As an example, as shown in FIG. 31, the hydrophobic portion 108 is formed into a substantially rectangular parallelepiped shape by molding an inorganic material such as stone aggregate, or a well-known underdrain hydrophobic material such as rice husk, wood chip, shell, or polystyrene foam. Formed and embedded in the ground adjacent to the perforated tube 24. By doing so, water that has oozed out from the ground of the cultivated land 200 into the hydrophobic portion 108 is collected, and the water moves from the through hole 26 on the upper side of the perforated pipe 24 to the inside of the perforated pipe 24. Then, the water that has flowed through the perforated pipe 24 flows into the second water distribution pipe 32 and is discharged to the water storage tank 34.

  Further, it is not always necessary to provide the perforated tube 24 and the hydrophobic portion 108 separately. As shown in FIG. 32, the cross-sectional shape of the perforated tube 24 is an elliptical or elliptical ring shape that is long in the vertical direction. In this way, the upper space may function as the hydrophobic portion 38.

  It should be noted that the specific numerical values such as the diameter and height described above are merely examples, and can be appropriately changed as necessary.

DESCRIPTION OF SYMBOLS 10 ... Underground irrigation system 12 ... Impermeable member 14 ... Water retention member 16 ... Water supply member 24 ... Perforated pipe 38 ... Soil part of capillary water state 46 ... Partition part 50 ... Soil part of capillary water state or gravity water state 62 ... Water level Detection means 64 ... Water supply control means 80 ... Water level manager 200 ... Cultivated land

Claims (13)

A water-impervious member that is formed in a container shape with an upper opening and is embedded in an inclined manner in the ground of the cultivated land,
A water retention member provided at least at the bottom of the water impermeable member, and a water supply member that is disposed in the water impermeable member via the water retention member and supplies water supplied from a water supply source to the water retention member. Underground irrigation system.   2. The underground irrigation system according to claim 1, further comprising a water storage means provided downstream of the water supply member and into which surplus water inside the water supply member flows.   The underground irrigation system according to claim 2, further comprising a circulation means for returning the water stored by the water storage means to the water supply source. The water supply member includes a perforated pipe having a plurality of through holes formed in a pipe wall,
The perforated pipe is also used as a water collecting member for collecting surplus water inside the water shielding member, and surplus water collected by the water collecting member is discharged to the water storage means. 3. Underground irrigation system. A water-impervious member formed in a container shape with an upper opening and buried in the ground of the cultivated land,
A water retaining member provided at least at the bottom of the water shielding member,
A water supply member that is disposed in the water-impervious member via the water retention member and supplies water supplied from a water supply source to the water retention member, and a water level supplied to the water retention member from the water supply member is detected. An underground irrigation system comprising: a water level detection unit that controls water supply from the water supply member to the water retention member based on a detection result of the water level detection unit. The water-impervious member is embedded in the ground of the cultivated land,
The water level detection means is installed at the inclined lower end of the water shielding member,
The underground irrigation system according to claim 5, wherein the water supply control unit includes a water supply stop unit that stops water supply from the water supply member to the water retention member based on a detection result of the water level detection unit. A water-impervious member that is formed in a container shape with an upper opening and is embedded in an inclined manner in the ground of the cultivated land,
A water retaining member provided at least at the bottom of the water shielding member, and disposed in the water shielding member with the water retaining member interposed between the water shielding member and the bottom of the water shielding member, and supplied from a water supply source. An underground irrigation system comprising a water supply member that supplies water to the water retaining member.   The vertical position of the water supply member is positioned by placing the water supply member on the soil that is not cultivated with the water-impervious member interposed therebetween in the ground of the cultivated land. Underground irrigation system.   The underground irrigation system according to claim 8, wherein the water supply member is placed on the upper side of the second position that is higher in a step shape than the lowest first position among the bottoms in the water shielding member.   The underground irrigation system according to any one of claims 1 to 9, further comprising a partition portion that partitions a bottom portion in the water shielding member at a predetermined interval in a direction in which the water shielding member is installed.   The underground irrigation system according to any one of claims 1 to 10, wherein the water retaining member includes soil of the cultivated land. The water supply member includes a perforated pipe that is also used as a water collecting member for collecting surplus water inside the water shielding member, and a hydrophobic portion is provided above the perforated pipe. An underground irrigation system according to any of the above.
The water supply member A water-impervious member formed in a container shape with an upper opening and embedded in the ground of the cultivated land, and a water retention member provided at the bottom of the water-impervious member,
An underground irrigation system comprising a water supply member that is disposed in the water-impervious member via the water retention member and that supplies water supplied from a water supply source to the water retention member.

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