JP5731791B2 - Irrigation system and method - Google Patents

Description

The present invention is, for example, the Middle East, and semi-arid areas and dry areas such as Africa, in areas such as water scarcity is an issue, of the preferred irrigation systems and irrigation methods can be effectively utilized water resources Is a field.

  As a conventional irrigation method, a cylindrical water storage container made of unglazed pottery is embedded in the soil for plant cultivation, water is supplied from the water storage tank to the water storage container, and the water permeated from the peripheral wall of the water storage container is used for the soil for plant cultivation. There is one in which irrigation is carried out by supplying the water (Japanese Patent Laid-Open No. 10-66462, FIG. 1 (Patent Document 1)).

  However, in the conventional irrigation method described above, the water level of the water storage tank is not constant. For this reason, when the water level of the water storage tank is high, the water pressure applied to the water storage container is high, and there is a lot of water that permeates from the peripheral wall of the water storage container, providing more water than is suitable for plant cultivation. There is a problem of supplying wasteful irrigation water. Furthermore, this wasteful supply of irrigation water causes a problem that the soil for plant cultivation becomes excessive in water and causes root decay of the plant. On the other hand, when the water level of the water storage tank is low, the water pressure applied to the water storage container is low, and the amount of water that permeates from the peripheral wall of the water storage container is small, so that it is not possible to provide an amount of water suitable for plant cultivation. There is a problem that the plant will die. In other words, the conventional irrigation method always has a drawback that the water level always changes, and therefore it is impossible to supply a certain amount of water to the plant.

  In addition, water that permeates from the peripheral wall of the water storage container is sucked not only by the roots of the plant but also by the soil for plant cultivation. Therefore, for example, the soil for plant cultivation outside the area where the plant root is located, for example, below the water storage container. The problem is that it is also sucked in and supplies wasteful irrigation water.

  In addition, if the groundwater contains salt, there is nothing to block the rise of the groundwater containing salt, so salt damage caused by salt contained in the groundwater cannot be prevented, and sustainable farming is not possible. There's a problem.

Japanese Patent Laid-Open No. 10-66462, FIG.

An object of the present invention, it is possible to reduce the supply of useless irrigation water, it is possible to prevent the death of root rot or Plants, and further irrigation system Ru can prevent salt damage To provide irrigation methods.

In order to solve the above problems, the irrigation system of the present invention provides:
A constant water pressure generator that generates a constant water pressure in accordance with the characteristics of the porous hose shown below,
An irrigation device comprising a porous hose connected to the constant water pressure generator ;
A soil water permeation suppression layer that is located in the soil and that consists of particles of waste glass with a particle size larger than that of sand and suppresses the penetration of soil water;
With
The porous hose is arranged in the soil above the soil water permeation suppression layer .

  Here, the porous hose is made of a porous material having micropores that allow water or water vapor to pass through only slightly. This porous hose means the amount of water or water vapor that passes through the hose peripheral wall (meat) from the inside of the hose to the outside by changing the material or dimensions of the porous material. Similarly, the desired value can be obtained.

The irrigation system having the above configuration connects the porous hose to the constant water pressure generator. For this reason, irrigation water is automatically and stably applied to the porous hose by a certain amount of water pressure, which is absorbed according to the activity of the plant root (corresponding to the amount absorbed by the plant root). Can be supplied. Therefore, the supply of useless irrigation water can be reduced, and the watering effort can be reduced. This can prevent plant root rot and plant death, and can easily supply irrigation water without having to worry about the amount of irrigation water or the amount of water supplied to the irrigation device. . When a large water pressure is applied to the porous hose, a large water pressure difference is generated between the inlet end and the terminal end of the porous hose, resulting in a difference in the amount of leaching from the porous hose, and uniform irrigation cannot be performed. Therefore, it is preferable to select an appropriate and small water pressure in consideration of the relationship with the material and dimensions of the porous hose.

The proposed constant water pressure generator generates an appropriate small water pressure. For this reason, the constant water pressure generating device can be realized by using simple and inexpensive equipment such as a water tank that controls the water level by a ball tap method without using expensive equipment such as a pump.
Moreover, according to the irrigation system of the said structure, the said porous hose is connected to the said constant water pressure generator which generate | occur | produces a constant water pressure. For this reason, an appropriate small and constant water pressure is applied to the porous hose to automatically and stably supply irrigation water as much as it is absorbed according to plant root activity and soil humidity. can do. Therefore, the supply of useless irrigation water can be reduced, and the watering effort can be reduced. This can prevent plant root rot and plant death, and can easily supply irrigation water without having to worry about the amount of irrigation water or the amount of water supplied to the irrigation device. .
The soil water permeation suppression layer is composed of particles of waste glass having a particle size larger than that of sand, and the soil water is prevented from penetrating the soil water permeation suppression layer, while the groundwater containing salt is increased. Shut off. Therefore, soil water is retained in the soil above the soil water permeation suppression layer, so that the supply of useless irrigation water can be further reduced and salt damage can be prevented.
Furthermore, since the porous hose is disposed in the soil above the soil water permeation suppression layer in which soil water is retained, the soil around the porous hose has a small amount of water absorption, Wasteful irrigation water supply can be greatly reduced.

In one embodiment,
The constant water pressure generating device includes a container, a float provided in the container, and an open / close valve connected to the float to open and close a water supply port into the container.

  According to the embodiment, the water level in the container is detected by the float, the open / close valve is opened / closed according to the water level, and the amount of water supplied into the container is automatically adjusted. The water level in the container, that is, the water pressure can be made constant. Therefore, it is not necessary to make an expensive investment in equipment such as a pump, the constant water pressure generator can be configured simply and inexpensively, and maintenance is easy. Furthermore, since no electric power or power is used, maintenance costs such as electricity costs can be reduced. It is also suitable for areas where power and power infrastructure is not established.

Moreover, the irrigation method of the present invention comprises:
A soil water infiltration suppression layer that is located in the soil and that suppresses the infiltration of soil water consisting of particles of waste glass having a particle size larger than that of sand;
A constant water pressure generator that generates a suitable small constant water pressure;
With the porous hose that is located in the soil above the soil water permeation suppression layer and connected to the constant water pressure generator,
Irrigation is performed from the porous hose into the soil above the soil water permeation suppression layer.

  According to the irrigation method having the above configuration, the porous hose is connected to the constant water pressure generating device that generates a constant water pressure. For this reason, an appropriate small and constant water pressure is applied to the porous hose to automatically and stably supply irrigation water as much as it is absorbed according to plant root activity and soil humidity. can do. Therefore, the supply of useless irrigation water can be reduced, and the watering effort can be reduced. This can prevent plant root rot and plant death, and can easily supply irrigation water without having to worry about the amount of irrigation water or the amount of water supplied to the irrigation device. .

The soil water permeation suppression layer is composed of particles of waste glass having a particle size larger than that of sand, and the soil water is prevented from penetrating the soil water permeation suppression layer, while the groundwater containing salt is increased. Shut off. Therefore, soil water is retained in the soil above the soil water permeation suppression layer, further reducing the supply of useless irrigation water and preventing salt damage due to the rise of saltwater containing salt. Can do.

  Furthermore, since the porous hose is located in the soil above the soil water permeation suppression layer where the soil water is retained and performs irrigation, the soil around the porous hose absorbs water. Therefore, the supply of wasted irrigation water can be greatly reduced.

  According to the present invention, an appropriate small and constant water pressure is applied to the porous hose, and automatically and stably irrigated as much as it is absorbed according to the plant root activity and soil humidity. Water can be supplied. The soil water permeation suppression layer prevents soil water from permeating the soil water permeation suppression layer while blocking the rise of groundwater containing salt. Therefore, it is possible to reduce the supply of useless irrigation water, reduce watering effort, prevent plant root rot and plant death, and further prevent salt damage.

It is a schematic block diagram of the irrigation apparatus of one Embodiment of this invention. It is a figure explaining the effect of the soil water permeation suppression layer of the above-mentioned embodiment. It is a figure which shows the amount of daily irrigation water in the verification experiment of this invention. It is a figure which shows the condition of Kenya spinach at the time of the harvest in the test area (1) of the said demonstration experiment. It is a figure which shows the condition of the Kenya spinach at the time of the harvest in the test area (2) of the said demonstration experiment. It is a figure which shows the condition of Kenya spinach at the time of the harvest in the test area (3) of the said demonstration experiment. It is a figure which shows the condition of the Kenya spinach at the time of the harvest in the test area (4) of the said verification experiment. It is a figure which shows the condition of Kenya spinach at the time of the harvest in the test area (5) of the said demonstration experiment. It is a figure which shows the water utilization efficiency of the said demonstration experiment. It is a schematic block diagram of the modification which used the irrigation apparatus of the said embodiment for hydroponics.

  Hereinafter, the present invention will be described in detail with reference to illustrated embodiments.

  As shown in FIG. 1, the irrigation apparatus includes a constant water pressure generating device 10 and a porous hose 20 that is connected to the constant water pressure generating device 10 and embedded in soil.

  The constant water pressure generator 10 includes a container 11, a float 12, a link 13, and an on-off valve 14. The container 11 has a capacity of 15 L, and the container 11 contains water supplied from a water source, for example, a 200 L water supply tank that collects rainwater, and the float 12 provided in the container 11 Floating. For this reason, the height position of the float 12 in the container 11 is interlocked with the water level in the container 11. The float 12 and an on-off valve 14 for opening and closing a water supply port 15 for supplying water from the water supply tank into the container 11 are connected by a link 13, and the height position of the float 12, that is, in the container 11. The on-off valve 14 opens and closes according to the water level. An outlet pipe 16 is provided below the constant water pressure generator 10, and an opening / closing valve 17 that can be manually opened and closed is provided in the outlet pipe 16.

  The porous hose 20 is composed of a porous tube (trade name is a new material Unihose FAL-5000, manufactured by Unihose Co., Ltd.) formed by mixing ceramics with waste tires, and a cylinder with an outer diameter of 25.9 mm and an inner diameter of 17.7 mm. It is formed in a shape. The peripheral wall (meat) of the porous hose 20 has micropores through which water or water vapor passes slightly. The inlet end 112 of the porous hose 20 is connected to the outlet pipe 16 of the constant water pressure generator 10. In this example, the end 113 of the porous hose 20 is normally closed.

  In order from the porous hose 20 downward, the root group region 30, a soil water permeation suppression layer 40 made of particles having a particle size larger than sand, a lower layer soil 50, and groundwater 60 are formed. Specifically, the soil water permeation suppression layer 40 has a depth of 30 cm from the soil surface and a porous m (manufactured by Tottori Recycling Laboratory Co., Ltd.), a soil improvement material produced from waste glass, having a capacity of 80 L and a thickness. It is 3cm long and is laid on a weedproof sheet. On the other hand, the porous hose 20 is embedded in the root group region 30 having a depth of 5 cm from the soil surface with a horizontal interval of 30 cm, and is located in the soil above the soil water permeation suppression layer 40. Yes. A plant 70 is planted on the soil surface.

Since the porous m forming the soil water permeation suppression layer 40 is made of waste glass particles having a particle size larger than that of sand, a capillary barrier can be formed to prevent the soil water from falling and penetrating, while the salt content is reduced. Can prevent the rise of groundwater containing.

  FIG. 2 illustrates the amount of soil water in the soil when water is supplied from above the soil (for example, sandy soil). Specifically, FIG. 2 shows a porous alpha (manufactured by Tottori Recycling Laboratory Co., Ltd.) which is a soil improvement material produced from waste glass at a position 30 cm from the soil surface as the soil water permeation suppression layer 40. The soil moisture content in the soil at a position 15 cm from the soil surface is shown for each of the case where the layer is laid at a thickness of 2 cm and the case where the soil water permeation suppression layer is not provided. As shown in FIG. 2, when the soil water permeation suppression layer 40 is provided, the soil moisture in the soil located above the soil water permeation suppression layer 40 is greater than when the soil water permeation suppression layer is not provided. You can see that the amount is always large.

  The operation of the irrigation apparatus having the above configuration will be described in detail with reference to FIG.

  Water supplied to the container 11 from the water tank through the water supply port 15 is accumulated in the container 11. When the water level in the container 11 reaches a height of, for example, 9 cm from the soil surface, the water supply port 15 is closed by the on-off valve 14 connected to the float 12 that detects the water level, and the water source to the container 11 is closed. Water supply stops. On the other hand, when the water level in the container 11 reaches a height of 9 cm or less from the soil surface, the water supply port 15 is opened by the on-off valve 14 and water is supplied from the water source to the container 11. In this way, the water level in the container 11 can be automatically controlled to be a constant water level of 9 cm in height from the soil surface, and the water pressure generator 10 can generate a constant water pressure. Liquid fertilizer can be supplied together with water from the water tank.

  Next, the water accumulated in the container 11 flows into the porous hose 20 through the outlet pipe 16 and is temporarily held. At this time, the water retained in the porous hose 20 has a positional relationship between a height of 9 cm from the soil surface, which is the water level in the container 11, and a depth of 5 cm from the soil surface in which the porous hose 20 is embedded. It has a water head pressure of 14 cm. The water retained in the porous hose 20 passes from the inside of the porous hose 20 through the micropores on the peripheral wall of the porous hose 20 and is brought into the soil as indicated by an arrow a1 by the suction force (capillary phenomenon) of the soil. Supplied. The wet region 31 supplied with water penetrates into the root group region 30 and spreads. Then, the penetration of the water is suppressed by the soil water permeation suppression layer 40 located below the root group area 30. As a result, the supplied water is retained in the soil by the amount of water retention capacity of the soil in the root group region 30 above the soil water permeation suppression layer 40, and moistens the soil.

  The water retained in the soil of the root group area 30 is absorbed by the roots of the plant 70. As a result, when the soil moisture in the root group region 30 is insufficient, water is supplied from the porous hose 20 to the root group region 30 so as to compensate for the shortage. That is, once the soil water is retained in the root group region 30, water is supplied from the porous hose 20 to the root group region 30 by the amount absorbed by the roots of the plant 70.

  In addition, although the groundwater 60 containing salt rises by penetrating through the upper lower soil 50 as indicated by an arrow a2, the rise of the groundwater 60 is blocked by the capillary barrier formed by the soil water permeation suppression layer 40. Is done.

  According to the above embodiment, a constant water pressure of 14 cm water head, that is, a relatively small water pressure is applied to the porous hose 20, and the amount automatically absorbed by the root activity of the plant 70 and the soil humidity is automatically applied. And irrigation water can be supplied stably. Therefore, the supply of useless irrigation water can be reduced, and the watering effort can be reduced. As a result, root rot of the plant 70 and withering of the plant 70 can be prevented, and it is not necessary to worry about the amount of irrigation water or the amount of water supplied to the irrigation device, and irrigation water can be supplied easily. Can do.

  The soil water permeation suppression layer 40 is composed of a porous m having a particle size larger than that of sand, and prevents soil water from permeating the soil water permeation suppression layer 40, while increasing the groundwater containing salt. Shut off. Therefore, the soil water is retained in the root group region 30 above the soil water permeation suppression layer 40, so that the supply of useless irrigation water can be further reduced, and salt damage caused by the rise of groundwater containing salt Can be prevented. In addition, when water exceeding the water retention capacity enters the root group area 30 such as when heavy rain falls, the water passes through the soil water permeation suppression layer 40 as shown by the arrow a3 and penetrates downward. , The root group 30 does not have an excessive moisture state and does not have to worry about root rot.

  Furthermore, the water due to heavy rain saturates the soil water permeation suppression layer 40 having a particle size larger than that of sand and quickly permeates downward as shown by arrow a3 to recharge groundwater.

  Further, the water level in the container 11 is detected by the float 12, and the on-off valve 14 is opened / closed according to the water level to automatically adjust the amount of water supplied into the container 11, thereby The water level, that is, the water pressure can be made constant. Therefore, it is not necessary to make expensive capital investment such as a pump, the constant water pressure generator 10 can be configured simply and inexpensively, and maintenance is easy. Furthermore, since no electric power or power is used, maintenance costs such as electricity costs can be reduced. It is also suitable for developing countries that do not have power or power infrastructure.

  In addition, the porous hose 20 is a permeation suppression soil improvement material obtained by recycling a waste culture glass to the soil water permeation suppression layer 40 using a porous aeration hose produced by mixing ceramic with waste tires. Since Porous m is used, recycled materials can be used and it is friendly to the global environment.

  Further, as shown in FIG. 1, a maintenance on-off valve 114 is provided at the end 113 of the porous hose 20. This is because the air in the porous hose 20 is expelled at the start of water supply, or if foreign matter is mixed in the porous hose 20, the maintenance on-off valve 114 is opened and the air is fed back to make the contaminant porous. The quality hose 20 can be removed. It is possible to easily clean the inside of the porous hose 20 without digging up the porous hose 20 from the ground.

  In the above embodiment, the constant water pressure generating device 10 applies a constant water pressure of 14 cm to the porous hose 20, but the pressure applied to the porous hose 20 is not limited to a constant water pressure of 14 cm. That is, the pressure applied to the porous hose 20 varies depending on the type of soil and the type of plant, preferably a constant water pressure of a head of 0 cm to 2 m, more preferably a constant water pressure of a head of 1 cm to 1 m, more preferably It is set to a constant water pressure of 2 to 50 cm, more preferably 5 to 20 cm, more preferably 10 to 15 cm.

  Moreover, in the said embodiment, although the porous hose 20 was embed | buried in the root group area | region 30 of depth 5cm from the soil surface, if it is above the soil water permeation suppression layer 40, it will be in the plant 70 of a soil surface. Correspondingly, it may be arranged at any position in the soil.

  Moreover, in the said embodiment, although irrigated using the porous tube as the porous hose 20, other porous materials, such as a Sheper hose (made by Unihose Co., Ltd.), may be used, for example.

  In the above embodiment, the soil water permeation suppression layer 40 is provided by laying the porous m with a thickness of 3 cm at a position 30 cm from the soil surface. The position is not limited to 30 cm from the surface. The soil water permeation suppression layer 40 may be disposed at any position corresponding to the plant on the soil surface, and may have any thickness.

  Moreover, in the said embodiment, although porous m was used for the said soil water permeation suppression layer 40, for example, particles having a smaller particle size than other sand such as Porous Alpha (manufactured by Tottori Recycling Laboratory). You may use what has.

(Experimental example)
Next, the result of the demonstration experiment which verified the yield and water use efficiency of the plant of the irrigation apparatus of this embodiment is shown.

  This demonstration experiment was conducted at the Kenya Agricultural Research Institute Kathmani test site, 70 km southeast of Nairobi, Kenya. The soil at this Kathmani test site is 78% sand, 18% silt, 4% clay, and is classified as loamy sand.

  The size of one test plot in the demonstration experiment was 5.4 m long and 0.6 m wide, and five test plots indicated by the daily irrigation water volume (mm / day) in FIG. 3 were provided. In these five test zones, different irrigation methods were applied, (1) Bucket ground irrigation, (2) Constant water level ground irrigation, (3) Water irrigation by watering, (4) Constant water level with permeation suppression layer Kenya spinach was cultivated by underground irrigation and (5) Kenya bucket drip irrigation. In the constant water level underground irrigation in the test zones (2) and (4), irrigation was performed using the irrigation apparatus of the above embodiment. The test section (4) is the same as the above embodiment, and the soil permeation suppression layer was provided in the soil, and irrigation was performed using the irrigation apparatus. In the underground irrigation in the test area (1), irrigation was performed by supplying water using a commercially available bucket having a volume of 19 L instead of the constant water pressure generator 10 of the irrigation apparatus. In the manual irrigation in the test section (3), water was irrigated using a commercially available 9 L watering can. The Kenya-type bucket drip irrigation method in the test area (5) is drip irrigation with a 19 L bucket installed at a height of 1.15 m, an emitter interval of 30 cm, a lateral line length of 5.4 m, and an interval of 30 cm. In addition, in order to grasp the soil water content (volumetric water content) associated with irrigation, SM200 moisture sensor (manufactured by Delta T) and data logger GP1 are embedded at a depth of 10 cm in the center of each test zone. .

  In the demonstration experiment, first, Kenya spinach was sown on a 200-hole cell tray on July 8, 2010. On July 27, 20 L of compost mixed with goat dung, cow dung, straw and the like was applied to each of the test areas. On July 31st, Kenya spinach of the same size was selected from the cell tray, and 35 pieces were transplanted in each test section in a two-column, 30 cm-interval shape as shown in FIG. 4E described later. Kenya spinach was harvested on September 21 (75th day after sowing).

  As for the amount of irrigation water, 12 L of water was irrigated in all the test areas on July 31 at the time of transplantation, and then irrigated every day regardless of the weather. In the test plots (1) and (5), 19 L of water was irrigated once a day, and in the test plot (3), 9 L of water was irrigated once a day with the water. The constant water level underground irrigation in the above test zones (2) and (4) was used once the water level of the water tank connected to the constant water pressure generator 10 was measured once a day and the water level decreased. The amount of irrigation water was calculated. The pH value of the irrigation water was 7.3, and the electric conductivity was 0.021 dS / m.

  FIG. 3 shows the daily irrigation water amount in each of the test zones for 30 days from August 19 to September 18. Daily irrigation water volume is the daily irrigation water volume divided by the area of each test area (length 5.4m, width 0.6m). As shown in FIG. 3, in the test plots (2) and (4), the amount of irrigation water tends to increase from about 60 days after sowing. This shows that a large amount of water was irrigated from the irrigation device as the amount of water absorbed by the roots of Kenya spinach increased and the amount of water absorbed by the roots of Kenya spinach increased. The total amount of irrigation water for 52 days from August 1 to September 20 is 1038L for test zone (1), 817L for test zone (2), 498L for test zone (3), and test zone ( 4) was 2068L, and test section (5) was 1038L. Moreover, in the case of constant-water level underground irrigation with a seepage control layer in the test zone (4), since the soil was used to embed the porous m, compared to other test zones, a lot of water was first introduced. Irrigation water was needed.

  FIG. 4A to FIG. 4E are diagrams showing the state of the spinach at the time of harvesting in each of the test sections. As shown in FIGS. 4A to 4E, the growth is good in the order of the test group (2), the test group (4), the test group (1), the test group (5), and the test group (3).

  FIG. 5 is a diagram showing the water use efficiency of the demonstration experiment. Here, the water use efficiency is a value obtained by dividing the dry weight of harvested plants by the amount of irrigation water supplied. Specifically, for the 30 days from the 45th day after sowing to the harvest on September 21 (75th day after sowing), the amount of irrigation water supplied during that period and the dry weight of harvested Kenya spinach were used. The water use efficiency was calculated. The average dry weight was calculated from 10 samples of Kenya spinach harvested from each test plot. The average dry weight of spinach was calculated as 35 uniformly growing in each test plot. The dry weight was calculated. As shown in FIG. 5, it was found that the water utilization rate of the test section (1) was higher than that of the test section (5), and that the underground irrigation had a water saving effect than the Kenya bucket drip irrigation. Moreover, it turned out that the water utilization rate of a test plot (4) is higher than a test plot (2), and the soil permeation suppression layer 40 plays a big role in water saving.

  From the above demonstration experiment, it was found that the embodiment of the present invention can significantly reduce the supply of useless irrigation water compared to the conventional irrigation method and can perform irrigation with very high water use efficiency.

(Modification)
FIG. 6 is a schematic configuration diagram of a modified example in which the irrigation device of the present invention is used for nutrient solution cultivation in a vegetable factory or the like.

  The modification shown in FIG. 6 includes the irrigation device and a container 110 for hydroponics. The container 110 is made of a polystyrene foam that does not transmit water and water vapor, and is a substantially sealed container. The porous hose 20 of the irrigation device is disposed in the lower part of the container 110, while the plant 70 is disposed on the upper surface of the container 110, and the root portion of the plant 70 extends from the upper surface of the container 110 to the container 110. It extends to the internal space 111 of.

  The water supplied from the constant water level generator 10 of the irrigation device is once held inside the porous hose 20, then passes through the micropores in the peripheral wall of the porous hose 20 and evaporates into the internal space 111. . Since the container 110 is substantially sealed, the internal space 111 of the container 110 is saturated with water vapor. Here, the root portion of the plant 70 absorbs water vapor in the air according to the activity of the root. When the amount of water vapor in the internal space 111 decreases from the saturated state, water vapor is supplied from the porous hose 20 to the internal space 111 so as to compensate for the decrease. Therefore, irrigation water can be automatically and stably supplied from the porous hose 20 as much as it is absorbed according to the root activity of the plant 70.

DESCRIPTION OF SYMBOLS 10 Constant water pressure generator 11 Container 12 Float 13 Link 14 On-off valve 15 Water supply port 16 Outlet pipe 17 On-off valve 20 Porous hose 30 Root group area 31 Wet area 40 Soil water permeation suppression layer 50 Lower soil 60 Groundwater 70 Plant 110 Container 111 Internal space 112 Inlet end 113 End 114 Maintenance on / off valve

Claims (3)

A constant water pressure generator for generating a constant water pressure;
A porous hose connected to the constant water pressure generator;
An irrigation device comprising:
A soil water permeation suppression layer that is located in the soil and that consists of particles of waste glass with a particle size larger than sand and suppresses the penetration of soil water,
An irrigation system, wherein the porous hose is arranged in the soil above the soil water permeation suppression layer. The irrigation system according to claim 1.
The constant water pressure generator is
A container,
A float provided in the container;
An irrigation system comprising: an open / close valve connected to the float and opening / closing a water supply port into the container. A soil water infiltration suppression layer that is located in the soil and that suppresses the infiltration of soil water consisting of particles of waste glass having a particle size larger than that of sand;
A constant water pressure generator for generating a constant water pressure;
With the porous hose that is located in the soil above the soil water permeation suppression layer and connected to the constant water pressure generator,
Irrigation method characterized by performing irrigation from the porous hose into the soil above the soil water permeation suppression layer.