JP7277313B2 - Water traps, irrigation devices, irrigation systems and methods of growing crops - Google Patents

Description

The present invention relates to a water trap, an irrigation device, an irrigation system, and a crop cultivation method.

Patent Literature 1, as shown in FIG. 1 thereof, discloses a sluice which is provided with an outer cylinder, an inner cylinder, and a blocking cover, and which adjusts the groundwater level. Here, the outer cylinder extends upward from the bottom, and its lower end is connected to the drain port. The inner cylinder is provided inside the outer cylinder and has a plurality of through holes formed in the vertical direction. The closing cover is attached to the outer peripheral surface of the inner cylinder, and is configured to be able to close the plurality of through holes depending on the mounting position in the vertical direction with respect to the inner cylinder. Also, the drain port is formed at the bottom of the dam and connected to an underdrain pipe buried in the ground.

JP 2015-196954 A

By the way, the water trap disclosed in Patent Document 1 cannot adjust the length of the outer cylinder. Therefore, depending on conditions such as the shape of the ridge and the positional relationship between the ridge and the farmland in the vertical direction, the dam must be buried with the upper portion of the outer cylinder protruding from the ridge. A part of the dam protruding from the levees like the above-mentioned dam is not preferable because, for example, it interferes with mowing work and causes people to stumble when walking.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dam capable of adjusting the water level required for farmland while being able to be positioned so that the position of the top end is approximately the same as the position of the surface of the ridge.

A water lock according to a first aspect of the present invention is a bottomed cylinder that is buried in a ridge with the bottom wall facing downward, and two through holes are formed at different vertical positions on the peripheral wall. an outer cylinder, an inflow part that is fixed to the upper through-hole of the two through-holes and allows liquid to flow from the outside to the inside of the outer cylinder, and is fixed to the lower through-hole of the two through-holes. , an outflow portion for discharging the liquid from the inside to the outside; and a cylinder accommodated in the inside, which is lower than the inflow portion and spaced apart from the bottom wall and is the same as the outflow portion or more than the outflow portion. A slide that is fitted to and slidable in the upper part of the middle cylinder that can extend and contract along the vertical direction and the outer cylinder, the lower end of which is in contact with the peripheral wall over the entire circumference in the upper position. and a lid attached to the slide cylinder and capable of opening and closing an opening on the upper side of the slide cylinder. Positioned so as to be substantially the same as the position of the surface of the ridge, the middle tube is adjusted in length such that its upper end is positioned at the water level required for the farmland adjacent to the ridge.

A water lock according to a second aspect of the present invention is the water lock according to the first aspect, wherein the middle cylinder includes a telescopic cylinder that can be extended and contracted along the vertical direction, and a lower part that is attached to the lower side of the telescopic cylinder. The outer peripheral portion of the lower cap is an elastic member whose diameter gradually decreases from the upper side to the lower end, and the portion of the outer cylinder that contacts the elastic member extends from the upper side to the lower side. The middle cylinder is held by the outer cylinder in a state in which the outer peripheral portion is in contact with the inner peripheral surface.

A water lock according to a third aspect of the present invention is the water lock according to the second aspect, further comprising a shaft portion at least partially disposed inside the middle cylinder and fixed to the lower cap, the middle cylinder has an upper cap attached to the upper side of the telescopic cylinder, and the upper cap is adjusted to the length of the middle cylinder at which the upper end of the middle cylinder is at the required water level. and is fixed to the shaft portion.

A water lock according to a fourth aspect of the present invention is the water lock according to the second aspect or the third aspect, wherein the shaft portion includes a hollow shaft fixed to the lower cap and a hollow shaft fitted inside the hollow shaft. and a slide shaft slidable with respect to the hollow shaft, the slide shaft contacting the bottom wall and supporting the hollow shaft while being supported by the bottom wall, thereby moving the outer peripheral portion. It is in a state separated from the inner peripheral surface.

A water lock according to a fifth aspect of the present invention is the water lock according to any one of the second aspect to the fourth aspect, wherein the telescopic cylinder is a bellows.

A water lock according to a sixth aspect of the present invention is the water lock according to any one of the second aspect to the fourth aspect, wherein the telescopic cylinder has a plurality of cylinders each having a different diameter, and the plurality of cylinders are arranged in a mutually fitted state around an axis extending in the vertical direction, and are capable of expanding and contracting in the vertical direction as some of the plurality of cylinders move in the vertical direction. there is

An irrigation system according to a first aspect of the present invention comprises a water trap according to any one of the first aspect to the sixth aspect, and a liquid supplied from a main liquid supply pipe, and supplies the stored liquid to the farmland. and a channel part for connecting the inflow part and the supply part and transporting the liquid from the supply part to the inflow part, a part of the channel part being underground of the farmland. It is an underdrain pipe arranged and having a plurality of through-holes formed in its outer circumference.

The irrigation apparatus of the second aspect of the present invention is the irrigation apparatus of the first aspect, wherein the supply unit supplies the liquid, which is supplied from the main liquid supply pipe and stored, to the farmland and to the waterway unit. In accordance with the switching, the agricultural land used as one of paddy fields and fields can be used as the other.

An irrigation device according to a third aspect of the present invention is the irrigation device according to the first aspect or the second aspect, which is arranged adjacent to the farmland and is capable of draining liquid from the farmland from the farmland. when the farmland is used as a paddy field and the water level of the farmland in the vertical direction reaches a predetermined position above the position of the upper end of the middle cylinder. Drain the liquid on the field.

An irrigation device according to a fourth aspect of the present invention is the irrigation device according to the first aspect or the second aspect, and is arranged on the opposite side of the farmland to be used as a field across an open ditch, and the liquid is supplied from the open ditch. a drainable drain.

An irrigation device according to a fifth aspect of the present invention is the irrigation device according to the third aspect or the fourth aspect, wherein the drainer comprises a bottom plate, and a pair of bottom plates disposed at both ends in the width direction of the bottom plate. an opposing wall, and a connecting wall disposed on the side opposite to the farmland side in the depth direction of the bottom plate, connecting the opposing walls, and forming a through hole for draining the liquid on the farmland; and a shutter arranged at the center of the bottom plate in the depth direction, and having a shutter whose upper end position can be changed by sliding in the vertical direction, and the position of the upper end of the shutter is set at a predetermined position.

An irrigation device according to a sixth aspect of the present invention is the irrigation device according to the fifth aspect, wherein a recess is formed on the outer surface in the width direction of the pair of opposing walls.

An irrigation device according to a seventh aspect of the present invention is the irrigation device according to the fifth aspect or the sixth aspect, wherein the shutter includes a first plate arranged on the farmland side in the depth direction and the first A second plate is arranged on the opposite side with at least a part of the surface of the plate in contact with the back surface of the plate, the second plate is slidable in the vertical direction, and the pair of opposing plates The bottom plate, the pair of opposing walls, and the first plate are adjacent to the farmland by filling soil in a region closer to the farmland in the depth direction than the first plate in the opposing regions of the walls. Fixed.

An irrigation device according to an eighth aspect of the present invention is the irrigation device according to any one of the third aspect to the seventh aspect, wherein the surface of the first plate facing the farmland in the depth direction has a recess. is formed.

An irrigation device according to a ninth aspect of the present invention is the irrigation device according to the seventh aspect or the eighth aspect, wherein the first plate is slidable in the vertical direction, and the drainer has a When used as a field, the first plate and the second plate are arranged in a state separated from the bottom plate.

An irrigation system according to a tenth aspect of the present invention is the irrigation system according to any one of the fifth aspect to the ninth aspect, wherein the drainer is arranged between the connecting walls with the shutter in the depth direction interposed therebetween. An earth retaining plate is supported on the opposite side by the pair of opposing walls and has a dent or a through hole formed therein into which the soil to be filled enters.

An irrigation device according to an eleventh aspect of the present invention is the irrigation device according to any one of the fifth aspect to the tenth aspect, wherein the pair of opposing walls are arranged on the farmland side in the depth direction and on the upper side in the vertical direction. The portion is formed with an inclined surface gradually approaching the farmland side from the upper end toward the center in the vertical direction. It can be embedded flush with or substantially flush with the side surface.

The irrigation system of the first aspect of the present invention comprises a first irrigation device having the same configuration as the irrigation device of any one of the first to eleventh aspects, and any one of the first to eleventh aspects. and a second irrigation device having the same configuration as the irrigation device of one aspect, wherein both sides of the dam of the first irrigation device and the dam of the second irrigation device are farmlands. One of the first irrigation device and the second irrigation device is buried in a ridge and is used to use the farmland on one side of the ridge as a paddy field. The other irrigation device is used to use the farmland on the other side of the ridge as a field.

An irrigation system according to a second aspect of the present invention is the irrigation system according to the first aspect, further comprising a drainage pipe into which the liquid flowing out from the first irrigation device and the liquid flowing out from the second irrigation device flow. .

The method for cultivating crops according to the first aspect of the present invention uses the irrigation apparatus according to any one of the first to eleventh aspects, and the upper end of the middle cylinder is required for crops cultivated in the farmland. Crops are cultivated on the farmland by adjusting the position of the water level.

The method of cultivating crops according to the second aspect of the present invention uses the irrigation system of the first aspect or the second aspect, and the upper end of the middle cylinder is positioned at the water level required for the crops cultivated in the farmland. Cultivate crops on the farmland by adjusting the

The dam of the present invention can be positioned so that the position of the top end is approximately the same as the position of the surface of the ridge, while adjusting the water level required for the farmland.

1 is a schematic diagram showing a state in which one of two farmlands is used as a paddy field and the other farmland is used as a field using the irrigation system of the present embodiment; FIG. 1 is an overall view (schematic view) of a water lock of the present embodiment; FIG. FIG. 2 is an overall view (schematic view) of a take-out member that constitutes the sluice gate of the present embodiment; It is a partial sectional view of the lower part of the water gate of this embodiment. FIG. 4 is a diagram for explaining a state in which the slide cylinder that constitutes the water lock of the present embodiment is slid and fixed to the outer cylinder; FIG. 4 is a diagram for explaining a state in which an extendable tube (bellows) that constitutes the take-out member of the present embodiment is extended and retracted; FIG. 4 is a partial cross-sectional view of the lower portion of the water lock of the present embodiment, and is a diagram for explaining a state (set state) in which the take-out member is arranged in contact with the outer cylinder; FIG. 4 is a partial cross-sectional view of the lower portion of the water lock of the present embodiment, and is a diagram for explaining a state (offset state) in which the extraction member is separated from the outer cylinder; FIG. 2 is an overall view (schematic view) of the water lock of the present embodiment, and is a view for explaining a state during use. FIG. 4 is a partial cross-sectional view of the lower portion of the water gate of the present embodiment, for explaining the flow of water during use; It is a figure for demonstrating the case where farmland is used as a paddy field using the water trap of this embodiment, and the case where farmland is used as a field. FIG. 5 is a diagram for explaining flushing performed by moving the take-out member of the water trap of the present embodiment from the set position to the offset position; 2K is a diagram for explaining the movement of water in the farmland during the flushing explained in FIG. 2K; FIG. Fig. 2 is a perspective view of a drainer that constitutes the irrigation system of the present embodiment; It is a side view of the drainer of this embodiment. FIG. 10 is a diagram of a case where the drainer of the present embodiment is used for a paddy field, and is a view of a state in which water overflows from the drainer arranged adjacent to the paddy field. FIG. 10 is a diagram showing the case where the drainer of the present embodiment is used for paddy fields, in which the water level of the paddy field is maintained at the set water level of the drainer placed adjacent to the paddy field. is a diagram. FIG. 4C is a diagram showing the case where the drainer of the present embodiment is used for paddy fields, and the water level of the paddy field at a set water level lower than that in the case of FIG. 4B in the drainer arranged adjacent to the paddy field It is a figure of the state which maintains . FIG. 10 is a diagram of a case where the drainage device of the present embodiment is used for paddy fields, and is a diagram of a state in which the set water level of the drainage device arranged adjacent to the paddy field is set to 0 cm. It is a figure at the time of using the drainer of this embodiment for fields. It is a figure in case the drainer of this embodiment is utilized for fields, Comprising: It is a figure in the state in which the drainer comprises a part of clear ditch. It is a figure in the case of utilizing the drainer of this embodiment for fields, and is a figure in the state where the drainer opens the finishing plate and drains the water from the clear ditch. FIG. 2 is an enlarged view of a portion of the irrigation system used for the paddy field of FIG. 1, including a water trap and a drainer; FIG. 11 is an overall view (schematic view) of a take-out member that constitutes a water lock of a modified example;

≪Overview≫
The irrigation system 10 (see FIG. 1) of this embodiment will be described below. First, the function and configuration of the irrigation system 10 of this embodiment will be described. Next, the effects of this embodiment will be described. In addition, in all the drawings referred to in the following description, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

≪Function and configuration of irrigation system≫
FIG. 1 shows a state in which one of two farmlands FL sandwiching a ridge RD is used as a paddy field PF and the other farmland FL is used as a field TF using the irrigation system 10 of the present embodiment. 1 is a schematic diagram showing the . The irrigation system 10 of the present embodiment easily adjusts the water level of the farmland FL (the water level above the farmland FL and the water level below the farmland FL) to produce crops FP1 and FP2 (crop FP1). is an example of rice, and the crop FP2 is an example of vegetables such as wheat). Along with this function, the irrigation system 10 of the present embodiment adjusts the water level of each farmland FL to the optimal water level for each of the crops FP1 and FP2 so as to create an optimal soil environment for cultivating (or growing) the crops FP1 and FP2. It is possible to adjust to
In the following description, one of the two farmland FLs is used as a paddy field PF, and the other farmland FL is used as a field TF. The irrigation system 10 of the embodiment may use both of the two farmlands FL as the paddy field PF or the field TF.

An irrigation system 10 of the present embodiment includes, as an example, a plurality of (two in FIG. 1) irrigation devices 20 and a drain pipe 30, as shown in FIG. The drain pipe 30 serves as a liquid path into which water W (an example of liquid) flowing out from each irrigation device 20 flows.
Here, "water W" as used in this specification does not mean only a compound of hydrogen and oxygen represented by the chemical formula _H2O , but means water generally used in agriculture. . That is, the "water W" referred to in this specification may be a liquid containing a compound of hydrogen and oxygen and foreign matter other than the compound such as soil.

<Irrigation device>
Each irrigation system 20 includes, as shown in FIG. Water channels 29A and 29B (an example of transport pipes) are provided. A plurality of components (a dam 22, a supply trough 24, an in-farm water channel 26, a drainer 28, and a plurality of outflow channels 29A, 29B) constituting each irrigation system 20 are composed of the soil SO that constitutes the ridge RD and the farmland FL. embedded or fixed in While the irrigation system 10 of the present embodiment has a function of managing the water level of a plurality of farmlands FL, each irrigation device 20 of the present embodiment easily adjusts the water level of each farmland FL to produce crops FP1 or It has a function to manage the water level according to the growth stage of the crop FP2. Along with this function, the irrigation device 20 of the present embodiment adjusts the water level of each farmland FL to the optimal water level for each of the crops FP1 and FP2 so as to create an optimal soil environment for cultivating (or growing) the crops FP1 and FP2. It is possible to adjust to
A plurality of components constituting each irrigation device 20 will be described below.

[Water lock]
The dam 22 of this embodiment has a function of easily adjusting the water level of the farmland FL (the water level above the farmland FL and the water level below the farmland FL). As shown in FIGS. 1, 2J, 2L, and 6, the water gate 22 of the present embodiment is arranged on the ridge RD so that its upper end is substantially at the same position as the surface (upper surface) of the ridge RD. It is designed to be buried. Here, "substantially identical" in this specification means, for example, about ±5 cm in the vertical direction with respect to the surface of the ridge RD. The direction indicated by the arrow X in the drawings is the vertical direction, the direction indicated by the sign +X means the upper side in the vertical direction, and the direction indicated by the sign -X means the lower side.

FIG. 2A is an overall view (schematic view) of the water lock 22 of this embodiment. Also, FIG. 2B is an overall view (schematic view) of the extracting member 250 that constitutes the sluice gate 22 of the present embodiment.
As shown in FIGS. 2A, 2B, etc., the water lock 22 of this embodiment includes an outer cylinder 200, an inflow part 210, an outflow part 220, a slide cylinder 230, a lid 240, and a take-out member 250. ing.
In addition, the water lock 22 of the present embodiment is basically a bottomed cylinder that is buried in the ridge RD with the bottom wall 204 facing downward. An outer cylinder 200 in which two through holes 206A and 206B are formed, and an inflow portion fixed to the upper through hole 206A of the two through holes 206A and 206B and allowing water W to flow from the outside to the inside of the outer cylinder 200. 210, an outflow portion 220 that is fixed to the lower through hole 206B of the two through holes 206A and 206B and causes the water W to flow out from the inside to the outside, and a cylinder that is housed in the inside and is more than the inflow portion 210. The lower end portion is in contact with the peripheral wall 202 over the entire circumference at a position equal to or above the outflow portion 220 spaced from the bottom wall 204, and can be expanded and contracted along the vertical direction. It has a cylinder 252, a slide cylinder 230 that fits in the upper part of the outer cylinder 200 and is slidable, and a lid 240 that is attached to the slide cylinder 230 and can open and close the upper opening of the slide cylinder 230. . The slide cylinder 230 is positioned so that the vertical position of the lid 240 in the state where the opening is closed is substantially the same as the position of the surface of the ridge RD, and the middle cylinder 252 has its upper end adjacent to the ridge RD. The length is adjusted to the position of the water level required for the farmland FL.

<Outer cylinder>
The outer cylinder 200 is a bottomed cylinder (bottomed cylinder). That is, the outer cylinder 200 has a peripheral wall 202 and a bottom wall 204 . As an example, the outer cylinder 200 has a cylindrical shape. The outer cylinder 200 is embedded in the ridge RD with the bottom wall 204 on the lower side in the vertical direction (see FIGS. 1, 2A, etc.). Two through-holes 206A and 206B are formed on the lower side of the peripheral wall 202 in the vertical direction, ie, the portion on the bottom wall 204 side (see FIG. 2C). The two through-holes 206A and 206B are formed at different vertical positions in the peripheral wall 202, that is, at positions offset in the vertical direction. As an example, the two through holes 206A and 206B open in opposite directions in the radial direction of the peripheral wall 202 .
As shown in FIG. 2C, an inner wall 208 having an inner peripheral surface 208A whose diameter gradually decreases from the upper side to the lower side in the vertical direction is provided in the lower portion of the outer cylinder 200 in the vertical direction. It is The technical meaning of the inner peripheral surface 208A will be described later.

<Inflow part and outflow part>
The inflow portion 210 is fixed to the upper through-hole 206A in the vertical direction of the two through-holes 206A and 206B, and serves as a member for causing the water W to flow from the outside of the outer cylinder 200 into the inner IS (FIG. 2A). , FIG. 2H, FIG. 2I, etc.). The inflow portion 210 has a cylindrical shape, and is fixed to the peripheral wall 202 of the outer cylinder 200 at one end thereof while being fitted in the through hole 206A. The other end of the inflow part 210 is connected to the intra-farm water channel 26, which will be described later (see FIG. 1).
The outflow portion 220 is fixed to the lower through hole 206B in the vertical direction of the two through holes 206A and 206B, and serves as a member for causing the water W to flow out from the inner IS of the outer cylinder 200 to the outside. (Refer to FIG. 2A, FIG. 2H, etc.). The outflow portion 220 has a cylindrical shape, and is fixed to the peripheral wall 202 of the outer cylinder 200 at one end thereof while being fitted in the through hole 206B. The other end of the outflow part 220 is connected to an outflow channel 29A, which will be described later (see FIG. 1).

<Slide cylinder and lid>
The slide cylinder 230 is, for example, a cylinder with both ends opened. As shown in FIG. 2A, the slide cylinder 230 is arranged on the upper part of the outer cylinder 200 in the vertical direction. Further, the slide cylinder 230 is fitted to the inner peripheral surface of the slide cylinder 230 with the outer peripheral surface of the outer cylinder 200 facing the outer cylinder 200, and is slidable with respect to the outer cylinder 200 (see FIG. 2D). The slide cylinder 230 is fixed to the outer cylinder 200 by a fixing member (not shown) such as a screw within a slidable range. A female screw (not shown) is formed on the inner periphery of the upper end portion of the slide cylinder 230 for fixing the lid 240 described later.
The lid 240 is attached to the slide cylinder 230 and is capable of opening and closing the upper opening of the slide cylinder 230 in the vertical direction. A male thread (not shown) that fits with the female thread of the slide cylinder 230 is formed on the outer periphery of the lid 240 .
With the above configuration, the slide cylinder 230 (see FIG. 2A) to which the lid 240 is attached, that is, the slide cylinder 230 in a state in which the opening at the upper end portion is closed by the lid 240, as shown in FIG. (the position of the upper end of the slide cylinder 230) is substantially the same as the position of the surface (upper surface) of the ridge RD.

<Extraction member>
The ejecting member 250 is adapted to be housed in an inner IS formed by an outer cylinder 200 and a slide tube 230 fitted to the outer cylinder 200, as shown in FIG. 2A. It is a member that can be removed from the inner IS of the outer cylinder 200 and the slide cylinder 230 . 2B is an overall view (schematic view) of the extraction member 250 extracted from the inner IS of the outer cylinder 200 and the slide cylinder 230. FIG. The extraction member 250 has a middle cylinder 252 and a shaft portion 254, as shown in FIG. 2B.

(middle barrel)
The middle tube 252 is accommodated in the inner IS of the outer tube 200 and the slide tube 230, and is vertically extendable. The middle tube 252 is used after being adjusted to a length at which the upper end thereof reaches the water level required for the farmland FL adjacent to the ridge RD (see FIG. 1).
The middle tube 252 has an extendable tube 252A, a lower cap 252B, an upper cap 252C, and a fixing screw 252D, as shown in FIG. 2B.

As shown in FIGS. 2A and 2B, for example, the extensible tube 252A is open at both ends and has an extendable bellows peripheral wall.

The lower cap 252B is attached to the lower portion of the telescopic cylinder 252A in the vertical direction. The lower cap 252B, which appears to be a cylindrical member (see FIG. 2B), penetrates vertically and is fixed to a hollow shaft 254A, which will be described later.
A part of the lower cap 252B is an elastic member 252B1 whose diameter gradually decreases from the upper side to the lower side in the vertical direction. Here, in this embodiment, the elastic member 252B1 is made of rubber as an example. When the middle tube 252 is used, the elastic member 252B1, which is the lower end portion of the telescopic tube 252A, is in contact with the inner peripheral surface 208A of the inner wall 208, which is a part of the outer tube 200, over the entire circumferential direction. , is held by the outer cylinder 200 (see FIG. 2C). In this case, the position of the lower cap 252B in the vertical direction is below the vertical upper through-hole 206A of the two through-holes 206A and 206B formed in the outer cylinder 200 and the bottom wall of the outer cylinder 200. 204 is set to be the same as or above the through hole 206B. That is, the vertical position of the lower cap 252B in this case is set to be below the inflow portion 210 and above the outflow portion 220 that is spaced apart from the bottom wall 204 of the outer cylinder 200. .

As shown in FIGS. 2A and 2B, the upper cap 252C is attached to the upper portion of the telescopic cylinder 252A in the vertical direction. The upper cap 252C, which appears to be a cylindrical member (see FIG. 2B), penetrates vertically and is fixed to a hollow shaft 254A, which will be described later, with a fixing screw 252D. . Specifically, the upper cap 252C is adjusted to the length of the middle cylinder 252 where the upper end of the middle cylinder 252 (the upper end of the upper cap 252C) is at the position of the water level required for the farmland FL, and the shaft It is designed to be fixed to the part.

(shaft part)
The shaft portion 254 has a hollow shaft 254A, a slide shaft 254B, and a clasp 254C, as shown in FIG. 2B.

Hollow shaft 254A is secured to lower cap 252B as previously described. In this case, the hollow shaft 254A is arranged at a position overlapping the axis of the middle tube 252. As shown in FIG. The hollow shaft 254A is fixed to the lower cap 252B so that its lower end does not protrude downward from the lower cap 252B. Further, the length of the hollow shaft 254A is set longer than the length of the middle tube 252 when the telescopic tube 252A is extended to reach its maximum length. Therefore, the hollow shaft 254A protrudes from the upper end of the middle tube 252 (the upper end of the upper cap 252C) regardless of the telescopic length of the telescopic tube 252A. In other words, a part of the hollow shaft 254A is arranged inside the inner cylinder 252 IS.

The slide shaft 254B is fitted inside the hollow shaft 254A and is slidable relative to the hollow shaft 254A (see FIGS. 2F and 2G). Also, the slide shaft 254B can be fixed to the hollow shaft 254A using a fixing member 254D.
The slide shaft 254B is normally fixed to the hollow shaft 254A with its lower end aligned with the lower end of the hollow shaft 254A. On the other hand, when the slide shaft 254B is fixed at a predetermined position lower than the normal state, the slide shaft 254B contacts the bottom wall 204 of the outer cylinder 200 and is supported by the bottom wall 204 while moving the hollow shaft 254A. It is adapted to support (see FIG. 2G). Accordingly, in the slide shaft 254B, the outer peripheral portion of the elastic member 252B1 is separated from the inner peripheral surface 208A of the inner wall 208 (see FIG. 2G).

[Supply Mass]
Next, the supply mass 24 of this embodiment will be described with reference to FIG. The supply trough 24 has a function of storing the water W supplied from the main liquid supply pipe MS, a function of supplying the stored water W to the farmland FL (paddy field PF), and an outflow of the stored water W to the waterway 26 in the farmland. It has the function of The supply mass 24 includes a container 24A for storing water W supplied from the main liquid supply pipe MS through the pipe D1, an L-shaped pipe D2 for supplying the stored water W to the farmland FL, and a lid ( (illustration omitted).

A through hole is formed in the bottom wall of the container 24A through which one end of the tube D1 penetrates. is open within container 24A.
Further, another through hole through which one end of the in-farm water channel 26 penetrates is formed in the bottom wall of the container 24A, and the outer periphery of the one end of the in-farm water channel 26 extends through the other through hole in the bottom wall of the container 24A. Sealed on the peripheral surface, one end of the intra-farm water channel 26 is open within the container 24A.
A through hole through which the L-shaped tube D2 penetrates is formed in the side wall of the container 24A. One end is open inside the container 24A and the other end is open above the farmland FL.

With the above configuration, the water W supplied from the main liquid supply pipe MS through the pipe D1 flows out from the opening at one end of the pipe D1 into the container 24A of the supply mass 24 and is stored in the container 24A. It has become. When the opening at one end of the farmland water channel 26 is closed with a lid, the water W stored in the container 24A flows into the L-shaped pipe D2 from the opening at one end of the L-shaped pipe D2, The water flows out to the farmland FL from an opening at the other end of the L-shaped pipe D2. On the other hand, when the opening at one end of the L-shaped pipe D2 is closed with a lid, the water W stored in the container 24A flows into the farmland waterway 26 from the opening at the end of the farmland waterway 26. It is designed to flow in. That is, the supply tank 24 of the present embodiment can switch between supply of the water W supplied from the main liquid supply pipe MS and stored therein to the farmland FL and outflow to the intra-farmland water channel 26 by using the lid. It is In this embodiment, along with this switching, the farmland FL used as one of the paddy field PF and the field TF can be used as the other.
In this embodiment, the supply mass 24 is arranged on the opposite side of the dam 22 across the farmland FL.

[Farm land waterway]
Next, the intra-farm waterway 26 of this embodiment will be described with reference to FIG. The farmland waterway 26 connects an inflow portion 210 of the dam 22 and the supply trough 24 and serves as a waterway for transporting the water W from the supply trough 24 to the inflow portion 210 . A part of the farmland waterway 26 is an underdrain pipe 26A arranged underground in the farmland FL. A plurality of through holes are formed in the outer periphery of the underdrain pipe 26A.

[Drainer]
Next, the drainage device 28 of this embodiment will be described with reference to FIGS. 1, 3A and 3B. Here, FIG. 3A is a perspective view of the drainer 28, and FIG. 3B is a side view of the drainer 28. FIG.
The basic configuration of the drainer 28 of the present embodiment includes a bottom plate 300, a pair of opposing walls 310 arranged at both ends of the bottom plate 300 in the width direction, and one end of the bottom plate 300 in the depth direction. and has a connecting wall 320 formed with a through hole 322 for connecting the opposing walls 310 and allowing the water W flowing out to the drain pipe 30 to pass therethrough, and the other end side in the depth direction of the bottom plate 300 faces the farmland FL. a main body 360 arranged adjacent to the farmland FL in a folded state, a shutter 330 arranged in the center of the bottom plate 300 in the depth direction and slidable in the vertical direction to change the position of the upper end, and a shutter 330 in the depth direction of the bottom plate 300 and an earth retaining plate 340 supported by a pair of opposing walls 310 on the opposite side of the connecting wall 320 with the shutter 330 interposed therebetween.
As shown in FIG. 1, the drainer 28 of the present embodiment is arranged adjacent to the paddy field PF when the farmland FL is used as the paddy field PF, and is disposed adjacent to the paddy field PF when the farmland FL is used as the field TF. It is arranged at a position adjacent to the open ditch OD on the opposite side of the field TF across the OD. The drainer 28 of the present embodiment adjusts the water level of the water W in the paddy field PF when the farmland FL is used as the paddy field PF, and when the farmland FL is used as the field TF, the water W is discharged from the clear ditch OD. It has two functions of draining the water.
Here, in this specification, the structure having the above two functions is named "drainage device" for explanation, but the name of the structure having the above two functions is different from "drainage device". may For example, a "drainage device" may be replaced with a "drainage device."

Further, the drainer 28 of the present embodiment has the following functions when the farmland FL is used as the paddy field PF and when it is installed in the same paddy field PF together with the dam 22 described above.
That is, when the water level of the water W in the paddy field PF rises above (higher than) the water level set by the dam 22 for some reason (for example, heavy rain), the drainer 28 reduces the water level of the water W in the paddy field PF according to the setting. It has the function of preventing the water level from rising above a predetermined water level (see the broken line WL drawn at the upper end of the second plate 334 in FIG. 6).

As shown in FIGS. 3A and 3B, the drainer 28 of this embodiment has a box-like shape with a space formed therein, and includes a bottom plate 300, a pair of opposing walls 310, a connecting wall 320, It includes a shutter 330, an earth retaining plate 340, and an outflow portion 350 (an example of a connection portion). Here, the direction indicated by the arrow Z in the drawing is the depth direction of the drainer 28, the direction indicated by the sign +Z means the front side in the depth direction, and the direction indicated by the sign -Z means the back side. The direction indicated by the arrow Y is the width direction of the drainer 28, the direction indicated by the sign +Y means the front side in the width direction, and the direction indicated by the sign -Y means the back side in the width direction.
Hereinafter, an outline of each component (the bottom plate 300, the pair of opposing walls 310, etc.) of the drainer 28 will be described, and then details of each component will be described.

(Overview of each component of the drainer)
The bottom plate 300 has a rectangular shape when viewed from above (see FIG. 3A).
The pair of opposing walls 310 are arranged at both ends of the bottom plate 300 in the width direction and protrude upward in the vertical direction from the upper surface of the bottom plate 300 to face each other (see FIGS. 3A and 3B).
The connecting wall 320 is arranged at the far side end of the bottom plate 300 in the depth direction, and connects the far side ends of the bottom plate 300 in the depth direction of the opposing walls 310 constituting the pair of opposing walls 310 (FIG. 3A). reference).
The shutter 330 is arranged in the center of the bottom plate 300 in the depth direction, and is fitted into the pair of opposing walls 310 on both sides thereof (both ends in the width direction of the bottom plate 300), and is supported by the pair of opposing walls 310 while being vertically movable. It is slidable (see FIGS. 3A and 4A-4D).
The earth retaining plate 340 is arranged at the end of the bottom plate 300 on the front side in the depth direction (on the opposite side of the connecting wall 320 across the shutter 330) and supported by the pair of opposing walls 310 (see FIG. 3A). The height (length in the vertical direction) of the earth retaining plate 340 is set lower (shorter) than the height (length in the vertical direction) of the pair of opposing walls 310 and the connecting wall 320 (Fig. 3A reference).
The outflow part 350 has a cylindrical shape and is arranged so as to protrude further to the depth side from the back surface of the bottom plate 300 in the depth direction of the connecting wall 320 . It surrounds the formed through hole 322 (see FIG. 3B).

As described above, the drainer 28 of this embodiment forms an internal space surrounded by the bottom plate 300, the pair of opposing walls 310, the connecting wall 320, and the retaining plate 340. The front side in the depth direction and the upper side in the vertical direction are opened, and the back side is opened by the through hole 322 described above. The shutter 330 partitions the inner space at the center of the bottom plate 300 in the depth direction.
The drainer 28 of the present embodiment is arranged so that the front side of the bottom plate 300 in the depth direction, that is, the earth retaining plate 340 side faces the farmland FL (see FIG. 1). Specifically, when the farmland FL is used as the paddy field PF, the drainer 28 is arranged with the retaining plate 340 adjacent to the edge of the paddy field PF. is arranged with the retaining plate 340 adjacent to the end of the open channel OD. Further, in the present embodiment, the combination of the bottom plate 300, the pair of opposing walls 310, and the outflow portion 350 (an example of the main body 360) is, for example, an integrally formed hollow molded product. Moreover, the said combination is formed with resin, such as polyethylene, as an example.

Next, details of each component of the drainer 28 will be described.
(Bottom plate and pair of opposing walls)
As described above, the bottom plate 300 has a rectangular shape when viewed from above (see FIG. 3A).
On the front side of the bottom plate 300 in the depth direction and the upper side in the vertical direction of the pair of opposing walls 310, inclined surfaces 314 gradually approach the front side of the bottom plate 300 in the depth direction toward the center from the top end in the vertical direction. is formed. Therefore, when viewed from the front side in the width direction of the bottom plate 300, each opposing wall 310 has a shape in which a peripheral portion of one corner of a rectangular plate is obliquely cut (see FIG. 3B). .
A plurality of (two as an example) recesses 312 are formed along the depth direction of the bottom plate 300 on the outer surface of the bottom plate 300 in the width direction of each opposing wall 310 . The two recesses 312 are linear in the vertical direction. In this embodiment, of the two recesses 312, the length of the recess 312 on the front side in the depth direction of the bottom plate 300 is set shorter than the length of the recess 312 on the back side.
In addition, a recess (not shown) for supporting the shutter 330 and the retaining plate 340 is formed on the inner surface of the bottom plate 300 in the width direction of each of the opposing walls 310 .

(Connecting wall and outflow part)
As described above, the connecting wall 320 connects the ends of the opposing walls 310 constituting the pair of opposing walls 310 on the far side in the depth direction of the bottom plate 300 (see FIG. 3A). A circular through hole 322 is formed in a portion of the connecting wall 320 at the center in the width direction of the bottom plate 300 and the lower side in the vertical direction.
The outflow portion 350 surrounds the through hole 322 when viewed from the depth direction of the bottom plate 300 and protrudes further to the depth side from the surface of the connecting wall 320 on the depth side of the bottom plate 300 (see FIG. 3B). A male thread for attaching the outflow channel 29B is formed on the outer peripheral surface of the outflow part 350 (see FIG. 3B).

(shutter)
The shutter 330 is composed of two plates. In the present embodiment, the plate arranged on the front side of the bottom plate 300 in the depth direction of the two plates is the first plate 332, and the other plate is the second plate 334 (FIGS. 3A and 3B). See Figure 3B). The second plate 334 is arranged on the deep side of the bottom plate 300 in the depth direction with at least part of its front surface in contact with the back surface of the first plate 332 . The first plate 332 and the second plate 334 are vertically slidable while being supported by the pair of opposing walls 310 .
In addition, a plurality of (three as an example) recesses 332A are formed on the front side surface of the bottom plate 300 in the depth direction of the first plate 332 . The recesses 332A are linear along the width direction of the bottom plate 300 and arranged in the vertical direction.

(Earth retaining board)
As described above, the earth retaining plate 340 is supported by the pair of opposing walls 310 and is vertically slidable. Specifically, the earth retaining plate 340 is slidable so that it can be attached to and detached from the pair of opposing walls 310 . In addition, a plurality of (two as an example) recesses 340A are formed in the retaining plate 340 (see FIG. 3A). The two recesses 340A are linear along the width direction of the bottom plate 300 and arranged in the vertical direction. In this embodiment, the retaining plate 340 is formed with a plurality of recesses 340A, but the plurality of recesses 340A may be replaced with a plurality of through holes (not shown).

[Multiple outflow channels]
29 A of outflow channels of this embodiment are connected to the outflow part 220 (refer FIG. 2A etc.) of the water gate 22 at one end, and are connected to the drain pipe 30 at the other end. This constitutes a channel for the water W that flows out from the outflow part 220 and flows into the drain pipe 30 .
The outflow channel 29B of this embodiment is connected to the outflow part 350 (see FIG. 3B) of the drainer 28 at one end and to the drain pipe 30 at the other end. This constitutes a channel for the water W that flows out from the outflow portion 350 and flows into the drain pipe 30 .

The above is the description of the function and configuration of the irrigation system 10 of the present embodiment.

≪Action and effect≫
Next, the effects of this embodiment will be described with reference. Hereinafter, the effects of the dam 22 of this embodiment, the effects of the drainer 28 of this embodiment, the effects of the irrigation device 20 of this embodiment, the effects of the irrigation system 10 of this embodiment, Also, the effects of the method of cultivating the crops FP1 and FP2 using the irrigation device 20 or the irrigation system 10 of this embodiment will be described in the order described.

<Function and effect of water trap>
First, the effects of the water lock 22 of this embodiment will be described.

[First Effect (Water Lock)]
The water lock 22 of this embodiment includes a slide cylinder 230 that fits in the upper portion of the outer cylinder 200 and is slidable (see FIG. 2D). In addition, the water lock 22 of this embodiment includes an extendable cylinder 252A that can be extended and retracted in the vertical direction (see FIG. 2E).
With the above configuration, the water lock 22 of this embodiment can adjust the overall length in the vertical direction, and furthermore, the length of the telescopic cylinder 252A for adjusting the number of degrees required for the farmland FL can be adjusted (Fig. 2H , FIG. 2J, FIG. 2L, etc.).
Therefore, the dam 22 of the present embodiment can be flexibly positioned so that the position of the upper end is substantially the same as the position of the surface (upper surface) of the ridge RD, and the water level required for the farmland FL can be adjusted. (See FIG. 1, etc.).

[Second Effect (Water Lock)]
The middle tube 252 of this embodiment has a telescopic tube 252A, an upper cap 252C, and a fixing screw 252D (see FIG. 2A). Further, the telescopic cylinder 252A of the present embodiment has a bellows shape (FIGS. 2B, 2E, 2H, etc.). The upper cap 252C is fixed to the hollow shaft 254A while the fixing screw 252D is abutted against the hollow shaft 254A.
With the above configuration, the middle tube 252 of the present embodiment can be steplessly adjusted in length regardless of the bending pitch of the bellows.

[Third Effect (Water Lock)]
A removable lid 240 is attached to the upper end portion of the slide cylinder 230 of this embodiment (see FIGS. 2A and 2H). Therefore, the dam 22 of this embodiment does not require digging up the slide cylinder 230 buried in the soil SO when accessing the extraction member 250 housed in the inner IS of the outer cylinder 200 and the slide cylinder 230 .
Therefore, the water lock 22 of this embodiment can easily access the take-out member 250 while exhibiting the first effect.

[Fourth Effect (Water Lock)]
A part of the lower cap 252B of the middle cylinder 252 of this embodiment is an elastic member 252B1 whose diameter gradually decreases from the upper side to the lower side in the vertical direction (FIGS. 2C and 2I). again,
An inner wall 208 having an inner peripheral surface 208A whose diameter gradually decreases from the upper side to the lower side in the vertical direction is provided at the lower portion of the outer cylinder 200 (see FIG. 2C). When the middle cylinder 252 of the present embodiment is used, the elastic member 252B1, which is the lower end portion of the telescopic cylinder 252A, extends along the entire circumference in the circumferential direction. is held in the outer cylinder 200 (see FIGS. 2C, 2F and 2G).
Further, in this case, the position of the lower cap 252B in the vertical direction is below the upper through-hole 206A of the two through-holes 206A and 206B formed in the outer cylinder 200 and the position of the outer cylinder 200. The position is the same as or above the through hole 206B separated from the bottom wall 204 (see FIGS. 2C, 2I, etc.).
With the above configuration, the water lock 22 of the present embodiment can easily ensure the tight contact between the middle cylinder 252 and the outer cylinder 200 necessary for forming the flow path of the water W during use. In addition, the water lock 22 of the present embodiment can facilitate the attachment and detachment operations of the extraction member 250 (see FIGS. 2F and 2G).

[Fifth Effect (Water Lock)]
The shaft portion 254 of this embodiment has a hollow shaft 254A and a slide shaft 254B (see FIG. 2B). The slide shaft 254B is fitted inside the hollow shaft 254A and is slidable relative to the hollow shaft 254A (see FIGS. 2F and 2G). Also, the slide shaft 254B is fixed to the hollow shaft 254A using a fixing member 254D. When the slide shaft 254B is fixed at a predetermined position lower than the normal state (see FIG. 2F), the hollow shaft 254B contacts the bottom wall 204 of the outer cylinder 200 and is supported by the bottom wall 204. 254A (see FIG. 2G). Accordingly, the slide shaft 254B separates the outer peripheral portion of the elastic member 252B1 from the inner peripheral surface 208A of the inner wall 208 (see FIGS. 2G, 2K, 2L, etc.).
As described above, the water lock 22 of the present embodiment has a configuration that exhibits the fourth effect described above, and also has the shaft portion 254 that is composed of the hollow shaft 254A and the slide shaft 254B. Easy to move up and down. Along with this, the water trap 22 of the present embodiment can easily perform the flushing operation.

<Action and effect of drainer>
Next, the effects of the drainer 28 of this embodiment will be described.

[First effect (drainage device)]
The combination of the bottom plate 300, the pair of opposing walls 310, and the outflow portion 350 in the drainer 28 of this embodiment is an integrally formed hollow molded product. Moreover, the said combination is formed with resin, such as polyethylene, as an example. The combination is therefore relatively lightweight.
Therefore, the drainer 28 of this embodiment is easy to construct.

[Second effect (drainage device)]
When the farmland FL is used as the paddy field PF, the drainer 28 of the present embodiment is installed by filling the space between the shutter 330 and the retaining plate 340 with soil SO (see FIGS. 4A to 4D).
Therefore, the drainage device 28 of the present embodiment can be stably (strongly) installed even if the device itself is lightweight.

[Third effect (drainage device)]
A plurality of recesses 312 are formed in a pair of opposing walls 310 constituting the drainer 28 of this embodiment (see FIG. 3A). The drainer 28 of the present embodiment is buried in the ridge RD in a state in which the soil SO enters the plurality of depressions 312 (see FIG. 1).
Therefore, the drainage device 28 of the present embodiment can be stably (strongly) installed even if the device itself is lightweight.

[Fourth effect (drainage device)]
A plurality of recesses 332A are formed in the first plate 332 that constitutes the drainer 28 of the present embodiment (see FIG. 3A). The drainer 28 of the present embodiment is installed with the soil SO entering the plurality of recesses 332A (see FIGS. 1 and 4A to 4D).
Therefore, the drainage device 28 of the present embodiment can be stably (strongly) installed even if the device itself is lightweight.

[Fifth effect (drainage device)]
As described above, since the first plate 332 is formed with a plurality of recesses 332A (see FIG. 3A), the drainage device 28 of the present embodiment is stably installed. The second plate 334 is arranged on the opposite side of the internal space filled with the soil SO with the first plate 332 interposed therebetween (see FIGS. 4A to 4D). Therefore, the second plate 334 is slidable in the vertical direction without being affected by the soil SO (or in a state where it is difficult to be affected).
Therefore, the drainer 28 of the present embodiment can easily adjust the water level while exhibiting the above-described fourth effect (drainer) (see FIGS. 4A to 4D).

[Sixth effect (drainage device)]
A plurality of recesses 340A are formed in an earth retaining plate 340 that constitutes the drainer 28 of this embodiment (see FIG. 3A). The drainer 28 of the present embodiment is installed in a state in which the soil SO enters the plurality of recesses 340A (see FIGS. 1 and 4A to 4D).
Therefore, the drainage device 28 of the present embodiment can be stably (strongly) installed even if the device itself is lightweight.

[Seventh effect (drainage device)]
A pair of opposing walls 310 constituting the drainer 28 of the present embodiment is formed with an inclined surface 314 gradually approaching the front side of the bottom plate 300 in the depth direction from the upper end in the vertical direction toward the center ( 3A, 3B, 6, etc.).
Therefore, the drainage device 28 of this embodiment can be embedded in a hole formed in the side surface of the ridge RD with the inclined surface 314 flush or substantially flush with the side surface.

[Eighth effect (drainage device)]
A first plate 332 and a second plate 334 that constitute the shutter 330 of the drainer 28 of the present embodiment are vertically slidable (see FIGS. 1 and 5A). Further, the earth retaining plate 340 is detachable from the pair of opposing walls 310 as described above. That is, the retaining plate 340 is detachable from the combination of the bottom plate 300 , the pair of opposing walls 310 and the outflow portion 350 .
Therefore, when the farmland FL is used as the field TF, the drainer 28 of the present embodiment is installed on the front side of the bottom plate 300 in the depth direction (earth retaining plate 340 side) to form part of the open channel OD (part of the side wall of the open channel OD), it can be used as a drainage device for the open channel OD. In this case, as shown in FIGS. 5A to 5C, when the water W is discharged from the open channel OD, the earth retaining plate 340 is slid upward while the first plate 332 and the second plate 334 are slid upward. Let it be.
As described above, the drainer 28 of the present embodiment can utilize the farmland FL as the paddy field PF and the field TF.

<Effects of irrigation equipment>
Next, the effects of the irrigation device 20 of this embodiment will be described.

[First effect (irrigation device)]
The irrigation device 20 of this embodiment includes a cistern 22 and a drainer 28 (see FIGS. 1 and 6). When used for the paddy field PF (see FIG. 6), the position of the upper end of the second plate 334 can be set above the position where the water level of the paddy field PF is set by the dam 22 .
In this case, when the water level of the water W in the paddy field PF rises above (higher than) the water level set by the dam 22 for some reason (for example, heavy rain), the water drainer 28 adjusts the water level of the water W in the paddy field PF according to the setting. can be adjusted so that it does not rise above the specified water level.

[Second effect (irrigation device)]
As described above, the irrigation system 20 of this embodiment includes the dam 22 , the supply trough 24 and the intra-farm water channel 26 . Here, the water lock 22 has the function of easily adjusting the water level of the farmland FL (the water level above the farmland FL and the water level below the farmland FL), as described above (see FIGS. 1, 2J, etc.). In addition, as described above, the supply mass 24 can switch between supplying the water W supplied from the main liquid supply pipe MS and storing it to the farmland FL and flowing it out to the intra-farmland waterway 26 . Further, part of the farmland waterway 26 is an underdrain pipe 26A arranged underground in the farmland FL (see FIG. 1).
With the above configuration, the irrigation device 20 of the present embodiment combines the setting of the water level by the trough 22, the switching of the water W by the supply trough 24, and the in-farmland water channel 26 having the underdrain 26A, thereby turning the farmland FL into the paddy field PF. It can also be used for field TF (see Fig. 1 etc.).

Other effects of the irrigation system 20 of this embodiment are the same as those of the water trap 22 and the drainer 28, which are the components of the irrigation system 20. FIG.

<Effects of the irrigation system>
Next, the effects of the irrigation system 10 of this embodiment will be described.

[First effect (irrigation system)]
The irrigation system 10 of this embodiment includes a plurality of irrigation devices 20 and a drain pipe 30, as shown in FIG.
Therefore, the irrigation system 10 of this embodiment can use the plurality of farmlands FL as paddy fields PF and fields TF, respectively.

[Second effect (irrigation system)]
The irrigation system 10 of this embodiment uses a common drain pipe 30 for a plurality of farmlands FL (see FIG. 1). Therefore, the irrigation system 10 of this embodiment is effective in that it is not necessary to provide each drain pipe 30 for each irrigation device 20 .

<Action and effect of the method of cultivating crops using the irrigation device or irrigation system of the present embodiment>
Next, the effect of the method of cultivating the crops FP1 and FP2 using the irrigation device 20 or the irrigation system 10 of this embodiment will be described.

Depending on the type of the crops FP1 and FP2, it is desirable to adjust the water level of each farmland FL to an optimum water level so that the soil environment is optimum for each. For example, when soybeans are grown as the crop FP2, it is desirable to set the water level of the farmland FL at a depth of 20 cm to 40 cm from the ground surface. Further, for example, when cultivating garlic and pumpkin as crops FP2, it is desirable to set the water level from the farmland FL to a depth of 35 cm to 50 cm from the ground surface. Further, for example, when cultivating cucumbers as the crop FP2, it is desirable to set the water level from the farmland FL at a depth of 25 cm to 45 cm from the ground surface.

In the case of this embodiment, the crops FP1 and FP2 are cultivated using the irrigation device 20 or the irrigation system 10. FIG. As described above, the irrigation device 20 and the irrigation system 10 of the present embodiment are provided with the trough 22 of the present embodiment, so that the upper end of the middle tube 252 reaches the water level required for the crops FP2 cultivated in the farmland FL. position can be adjusted.
Therefore, according to the method of cultivating the crops FP1 and FP2 using the irrigation device 20 (and the irrigation system 10) of the present embodiment, the water level of the farmland FL can be adjusted to an optimum water level to cultivate the crops FP1 and FP2. That is, the method of cultivating the crops FP1 and FP2 using the irrigation device 20 (and the irrigation system 10) of the present embodiment can cultivate the crops FP1 and FP2 in the farmland FL with the optimum soil environment.
As used herein, "cultivating crops" means "producing crops." That is, the "crop cultivation method" means the "crop manufacturing method".

Other functions and effects of the irrigation system 10 of this embodiment are the same as those of the irrigation device 20, the water trap 22, and the drainer 28, which are components of the irrigation system 10. FIG.

The above is the description of the effects of the present embodiment.

While the present invention has been described with respect to specific embodiments by way of example, the present invention is not limited to the embodiments described above.

For example, in the present embodiment the irrigation system 10 comprises a trough 22 and a drainer 28 and has been described as having certain relationships between these components. However, each of these components may operate independently.

Further, for example, in the present embodiment, the expandable tube 252A forming the middle tube 252 of the water lock 22 has been described as a bellows (FIGS. 2B, 2E, 2H, etc.). However, the telescopic tube 252A does not have to be a bellows as long as it is a tube that expands and contracts along its length direction. For example, instead of the telescopic cylinder 252A of the present embodiment, the telescopic cylinder 252E of the modification shown in FIG. 7 may be used. Specifically, the telescopic tube 252E is, for example, a plurality of (four as an example in this modification) tubes 252E1 and 252E2 having different diameters (outer diameter and inner diameter) and the same length. , 252E3, 252E4. A plurality of tubes 252E1, 252E2, 252E3, and 252E4 are arranged in a state of being fitted to each other around an axis extending in the vertical direction. In addition, some of the plurality of tubes 252E1, 252E2, 252E3, and 252E4 (in this modification, one or more of the tubes 252E2, 252E3, and 252E4) move vertically. Along with this, the telescopic cylinder 252E can be extended and retracted in the vertical direction.
In addition, in the case of this modification, the telescopic tube 252E has four tubes 252E1, 252E2, 252E3, and 252E4. The telescopic cylinder 252E of this modified example can change its telescopic length between the following four states (first to fourth states). Here, the first state refers to a state in which the tubes 252E1, 252E2, and 252E3 are accommodated within the tube 252E4. The second state refers to a state in which the tube 252E3 is positioned at the upper limit position in the vertical direction with respect to the tube 252E4, and the tubes 252E2 and 252E1 are accommodated in the tube 252E3. In the third state, the tube 252E3 is positioned at the upper limit position in the vertical direction with the tube 252E4, the tube 252E2 is positioned at the upper limit position in the vertical direction with the tube 252E3, and the tube 252E1 is accommodated in the tube 252E2. state. In the fourth state, the cylinder 252E3 is positioned at the upper limit position in the vertical direction with the cylinder 252E4, the cylinder 252E2 is positioned at the upper limit position in the vertical direction with the cylinder 252E3, and the cylinder 252E1 is at the upper limit position in the vertical direction. It refers to the state in which the tube 252E2 is positioned, that is, the state in which the telescopic tube 252E in FIG. 7 is extended.
Then, the length of each state of the telescopic cylinder 252E of this modified example may be set to be the optimum length for each of the crops FP1 and FP2. For example, the setting when the telescopic cylinder 252E is in the first state is set for garlic and pumpkin as the crop FP2, and the setting when the telescopic cylinder 252E is in the second state is set for cucumber as the crop FP2. The setting when the tube 252E is in the third state may be the setting for soybeans as the crop FP2, and the setting when the telescopic tube 252E is in the fourth state may be the setting for the crop FP1 (rice, rice).
In the case of this modification, the setting operation for adjusting the water level by the operator is facilitated, which is effective in reducing the work burden on the operator.
In this modified example, the plurality of tubes 252E1, 252E2, 252E3, and 252E4 constituting the telescopic tube 252E is four, but the number may be two, three, or five or more. Also, although the plurality of tubes 252E1, 252E2, 252E3, and 252E4 have the same length, they may have different lengths. The quantity, length, etc. of each tube constituting the telescopic tube 252E may be changed according to the types of the crops FP1 and FP2.

10 irrigation system 20 irrigation device 22 dam 24 supply mass (supply unit)
24A container 26 farmland water channel 26A underdrain pipe 28 drainer 29A outflow channel 29B outflow channel 30 drain pipe 200 outer cylinder 202 peripheral wall 204 bottom wall 206A through hole 206B through hole 208 inner wall 208A inner peripheral surface 210 inflow portion 220 outflow portion 230 Slide cylinder 240 Lid 250 Extracting member 252 Middle cylinder 252A Expandable cylinder (bellows)
252B lower cap 252c Upper cap 252D 252D fixed screw 252E 252E11 cylinder 252E2 E3 cylinder 252E 252E3 -cylinder 252E 4 -cylinder 254B hollow shaft 254B slide shaft 254C slide shaft 254C fixing device 254D fixing material 300 pair of opponents 310 opposed walls 312 Dent 320 connection wall 322 Through hole 330 Shutter 332 First plate 332A Recess 334 Second plate 340 Earth retaining plate 340A Recess 350 Outflow portion 360 Main body FL Farmland FP1 Crop (rice)
FP2 Crops (vegetables such as wheat)
MS Main liquid supply pipe OD Open channel PF Paddy field RD Ridge SO Soil TF Field W Water (example of liquid)
WL Water level D1 Pipe D2 L-shaped pipe X Arrow (vertical arrow)
+X Vertical upper side -X Vertical lower side Y Arrow (width direction arrow)
+Y Front side in width direction -Y Back side in width direction Z Arrow (Arrow in depth direction)
+Z Front side in depth direction -Z Back side in depth direction

Claims (21)

an outer cylinder with a bottom that is buried in the ridge with the bottom wall facing downward, the outer cylinder having two through holes formed at different positions in the vertical direction on the peripheral wall;
an inflow portion fixed to the upper through-hole of the two through-holes and allowing liquid to flow from the outside to the inside of the outer cylinder;
an outflow portion that is fixed to the lower through-hole of the two through-holes and causes the liquid to flow out from the inside to the outside;
A cylinder housed in the inside, the lower end of which extends along the entire circumference in the circumferential direction at a position below the inflow portion and at the same position as the outflow portion separated from the bottom wall or above the outflow portion. a middle cylinder that is in contact with the peripheral wall and that can expand and contract along the vertical direction;
a slide cylinder that fits in the upper portion of the outer cylinder and is slidable;
a lid attached to the slide cylinder and capable of opening and closing an upper opening of the slide cylinder;
with
The slide cylinder is positioned so that the vertical position of the lid when the opening is closed is substantially the same as the position of the surface of the ridge,
The middle cylinder is adjusted to a length such that its upper end is at the water level required for the farmland adjacent to the ridge.
Water lock. The middle cylinder has a telescopic cylinder that can be extended and contracted along the vertical direction, and a lower cap attached to the lower side of the telescopic cylinder,
The outer peripheral portion of the lower cap is an elastic member whose diameter gradually decreases from the upper side to the lower end,
The portion of the outer cylinder that contacts the elastic member is an inner peripheral surface whose diameter gradually decreases from the upper side to the lower side,
The middle cylinder is held by the outer cylinder with the outer peripheral portion in contact with the inner peripheral surface,
A sluice according to claim 1. a shaft portion at least partially disposed inside the middle cylinder and fixed to the lower cap;
The middle cylinder has an upper cap attached to the upper side of the telescopic cylinder,
The upper cap is fixed to the shaft part in a state in which the upper end of the middle cylinder is adjusted to the length of the middle cylinder at the required water level.
The sluice according to claim 2. The shaft portion has a hollow shaft fixed to the lower cap, and a slide shaft fitted inside the hollow shaft and slidable with respect to the hollow shaft,
The slide shaft supports the hollow shaft while being supported by the bottom wall in contact with the bottom wall, thereby separating the outer peripheral portion from the inner peripheral surface.
The sluice according to claim 3 . The telescopic cylinder is a bellows,
The water trap according to any one of claims 2-4. The telescopic cylinder has a plurality of cylinders with different diameters,
The plurality of tubes are arranged in a state of being fitted to each other around an axis extending in the vertical direction, and expand and contract in the vertical direction as some of the plurality of tubes move in the vertical direction. it is possible,
The water trap according to any one of claims 2-4. A water trap according to any one of claims 1 to 6;
a supply unit that stores the liquid supplied from the main liquid supply pipe and supplies the stored liquid to the farmland;
a channel section for connecting the inflow section and the supply section and for transporting liquid from the supply section to the inflow section;
with
A part of the waterway portion is an underdrain pipe that is arranged underground in the farmland and has a plurality of through holes formed on the outer circumference.
irrigation equipment. The supply unit is capable of switching between supplying the stored liquid supplied from the main liquid supply pipe to the farmland and flowing it out to the water channel,
Along with the switching, making the farmland used as one of paddy fields and fields available as the other;
Irrigation device according to claim 7. a drainer disposed adjacent to the farmland and capable of discharging liquid on the farmland from the farmland;
with
When the farmland is used as a paddy field, the liquid drainer drains liquid from the farmland when the water level in the farmland in the vertical direction reaches a predetermined position above the upper end of the middle cylinder. to drain,
Irrigation device according to claim 7 or 8. a drainer disposed on the opposite side of the farmland used as a field across a clear ditch and capable of discharging liquid from the clear ditch;
9. Irrigation device according to claim 7 or 8, comprising: The drainer includes a bottom plate, a pair of opposing walls arranged on both end sides in the width direction of the bottom plate, and a pair of opposing walls arranged on the opposite side of the bottom plate to the farmland side in the depth direction to connect the opposing walls. , a connecting wall formed with a through hole for draining the liquid on the farmland, and a shutter arranged in the center of the bottom plate in the depth direction and slidable in the vertical direction to change the position of the upper end. have
The position of the upper end of the shutter is a predetermined position,
Irrigation device according to claim 9 or 10. A recess is formed on the outer surface in the width direction of the pair of opposing walls,
12. Irrigation device according to claim 11. The shutter includes a first plate arranged on the farmland side in the depth direction and a second plate arranged on the opposite side with at least part of the surface thereof in contact with the back surface of the first plate. having a board,
The second plate is vertically slidable,
The bottom plate, the pair of opposing walls, and the first plate are formed into the farmland by filling soil in a region closer to the farmland in the depth direction than the first plate in the opposing regions of the pair of opposing walls. fixed adjacent to
Irrigation device according to claim 11 or 12. A dent is formed on the surface of the first plate facing the farmland in the depth direction,
14. Irrigation device according to claim 13. The first plate is vertically slidable,
When the farmland is used as a field, the drainer is arranged with the first plate and the second plate separated from the bottom plate.
15. Irrigation device according to claim 13 or 14. The drainage device is supported by the pair of opposing walls on the opposite side of the connecting wall with the shutter interposed in the depth direction, and includes an earth retaining plate formed with a recess or a through hole into which the soil to be filled enters. have
Irrigation device according to any one of claims 11-15. An inclined surface gradually approaching the farmland side from the upper end toward the center side in the vertical direction is formed on the portion of the pair of opposing walls on the farmland side in the depth direction and on the upper side in the vertical direction,
The drainage device can be embedded in a hole formed in the side surface of the ridge with the inclined surface flush or substantially flush with the side surface.
Irrigation device according to any one of claims 11-16. a first irrigation device having the same configuration as the irrigation device according to any one of claims 8 to 17;
a second irrigation device having the same configuration as the irrigation device according to any one of claims 8 to 17;
with
The dam of the first irrigation device and the dam of the second irrigation device are buried in a ridge of which both sides are farmland,
one of the first irrigation device and the second irrigation device is used to use the farmland on one side of the ridge as a paddy field,
The other of the first irrigation device and the second irrigation device is used to use the farmland on the other side of the ridge as a field,
irrigation system. a drainage pipe into which the liquid flowing out from the first irrigation device and the liquid flowing out from the second irrigation device flow;
comprising
Irrigation system according to claim 18. Using the irrigation device according to any one of claims 7 to 17,
Cultivating crops in the farmland by adjusting the upper end of the middle tube to the position of the water level required for the crops cultivated in the farmland;
Crop cultivation method. Using the irrigation system according to claim 18 or 19,
Cultivating crops in the farmland by adjusting the upper end of the middle tube to the position of the water level required for the crops cultivated in the farmland;
Crop cultivation method.

Images