JP7377542B2 - Soil moisture meter, irrigation equipment and irrigation method - Google Patents

Description

The present invention relates to a soil moisture meter suitable for dry soil, and an irrigation device and irrigation method using the soil moisture meter.

It is very important to understand the degree of soil dryness in fields, orchards, etc. in order to perform appropriate irrigation. Various methods and devices for measuring soil moisture are known in the art. Such methods and devices are broadly divided into those that measure the volumetric moisture content or water content ratio of soil, and those that measure the pressure head (pF value) of soil moisture.

Although the volumetric water content or water content ratio of soil is an indicator of the degree of dryness of the soil, it is not suitable as an indicator of the drought stress that plants are subjected to. On the other hand, the pF value measured with a tensiometer etc. indicates the force required for plants to draw up water from the soil, and is an excellent indicator for understanding the drought stress that plants receive and the need for irrigation. There is.

Here, in dry soil where the pF value is 2.8 or more, the pF value cannot be accurately measured with a tensiometer. Therefore, Patent Document 1 proposes a soil moisture measuring device that can measure the degree of dryness of soil in a low moisture region with a pF value of 2.8 or more.

Further, Patent Document 2 discloses a soil moisture measuring device equipped with a pressure sensor and an automatic irrigation device using the same.

Japanese Patent Application Publication No. 2007-192631 Japanese Patent Application Publication No. 1-257260

The soil moisture measuring device disclosed in Patent Document 1 reads the amount of air that has entered a tube body from the position of the water surface. Here, in this soil moisture measuring device, since the inside of the tube is under negative pressure, the pressure sensor cannot accurately detect the position of the water surface. Therefore, in dry soil with a pF value of 2.8 or more, automatic irrigation using the output of a pressure sensor is difficult as disclosed in Patent Document 2.

One aspect of the present invention aims to realize a soil moisture meter and the like suitable for dry soil with a pF value of 2.8 or more, which can automatically detect measurement results.

In order to solve the above problems, a soil moisture meter according to one aspect of the present invention has a porous cup at the end of the tube into which liquid is inserted into the soil, and from the porous cup to the inside of the tube. A soil moisture meter in which the position of the liquid level in the tube changes depending on the amount of air entering the tube, the float member including a magnet and floating on the liquid, and the position of the float member being controlled by the magnetic force generated by the magnet. It has a magnetic sensor for detecting.

In order to solve the above problems, an irrigation device according to one aspect of the present invention has a porous cup at the end of the pipe body into which liquid enters, on the side to be inserted into the soil, and from the porous cup into the pipe body. A soil moisture meter that changes the position of the liquid level in the tube according to the amount of air entering the pipe, and a control device that includes a determination unit that determines whether or not to perform irrigation based on the position of the liquid level. , the soil moisture meter includes a float member that includes a magnet and floats on the liquid, and a magnetic sensor that detects the position of the float member by the magnetic force generated by the magnet, and the control device is configured to control the magnetic sensor. The determination unit further includes a result acquisition unit that calculates the amount of descent of the position of the float member per unit time based on the detection result of It is determined that it will be done.

In the irrigation device according to one aspect of the present invention, the irrigation device may further include an updating unit that resets the amount of descent when the amount of descent becomes equal to or greater than the predetermined threshold.

In the irrigation device according to one aspect of the present invention, the irrigation device may further include a notification unit that provides notification when it is determined that the position of the float member is lower than a predetermined position.

In order to solve the above problems, an irrigation method according to one aspect of the present invention includes: a porous cup provided at the end of a pipe into which liquid is inserted into the soil; and a float containing a magnet and floating on the liquid. and a magnetic sensor that detects the position of the float member by the magnetic force generated by the magnet, and the position of the liquid level in the tube changes depending on the amount of air entering the tube from the porous cup. An irrigation method using a soil moisture meter, which includes a detection step of detecting the amount of descent of the position of the float member per unit time, and irrigation that performs irrigation when the amount of descent exceeds a predetermined threshold. process.

According to one aspect of the present invention, it is possible to realize a soil moisture meter, etc. suitable for dry soil with a pF value of 2.8 or more, which can automatically detect measurement results.

1 is a schematic diagram showing a soil moisture meter according to an embodiment of the present invention. It is a schematic diagram showing an example of installation of the irrigation device concerning one embodiment of the present invention. FIG. 1 is a block diagram showing functional blocks of a irrigation device according to an embodiment of the present invention. It is a flow chart which shows an example of the irrigation method concerning one embodiment of the present invention.

[Soil moisture meter]
A soil moisture meter 10 according to an embodiment of the present invention will be described below with reference to FIG. The soil moisture meter 10 is a soil moisture meter capable of measuring soil moisture in a low moisture region where the pF value indicating soil moisture is dry to 2.8 or more. It is known that the drought stress that crops undergo when the soil dries out is correlated with the sugar content at the time of harvest, and crops such as citrus fruits are grown in dry soil with a pF value of 2.8 or more. In addition to citrus fruits, crops such as soybeans and high-sugar tomatoes are known to be cultivated in dry soil with a pF value of 2.8 or higher and subjected to drought stress. The soil moisture meter 10 is useful for managing soil moisture in low moisture areas in the cultivation of such crops.

The soil moisture meter 10 includes a tube body 11, a float member 12, a silicon plug 13, a porous cup 14, and a magnetic sensor 15. The soil moisture meter 10 has a porous cup 14 at the end of the tube body 11 into which the liquid W is inserted, on the side that is inserted into the soil. This is a configuration in which the position of the liquid level S changes.

The tube body 11 is a tubular member into which the float member 12 and the liquid W can be placed. The float member 12 is a member that has the property of floating on the liquid W. That is, the float member 12 is a member whose specific gravity is smaller than that of the liquid W. Furthermore, the float member 12 includes a magnet. Thereby, the float member 12 emits magnetic force.

The material of the tube body 11 is not particularly limited as long as it does not interfere with the magnetic force generated by the float member 12. For example, the tube body 11 may be formed of a transparent resin such as vinyl chloride so that the position of the liquid surface S of the liquid W can be visually confirmed. In this case, the tubular body 11 may be provided with a scale. However, as will be described later, since the soil moisture meter 10 can detect the position of the liquid level S using the magnetic sensor 15, these are not essential.

The liquid W put into the tubular body 11 may be water, or may be a liquid fertilizer or the like that uses water as a main solvent. Examples of water here include, but are not limited to, purified water, tap water, rainwater, groundwater, and water stored in dams and the like. It is preferable that the liquid W is the same liquid as the liquid used for watering the soil. Moreover, it is preferable that the liquid W is degassed.

The upper end of the tube body 11 is hermetically sealed with a silicon plug 13. In this specification, for convenience, the vertically upper direction of the soil moisture meter 10 inserted into the soil is referred to as an upper direction, and the vertically lower direction is referred to as a downward direction. The material of the silicon plug 13 is not particularly limited as long as it can seal the upper end of the tube body 11. That is, the silicone stopper 13 may be a rubber stopper, a resin stopper, or a stopper formed of other materials.

The porous cup 14 is a water permeable member provided at the lower end of the tube body 11. The soil moisture meter 10 can measure the moisture in the soil by inserting the porous cup 14 into the soil. When the soil moisture meter 10 is inserted into the soil and the pF value of the soil becomes 2.8 or more, the liquid W in the tube body 11 seeps out from the porous cup 14 into the soil, and air flows into the tube body 11. enters. The air that has entered the tube body 11 moves to the upper part of the tube body 11. If the pF value of the soil continues to be 2.8 or higher, air will accumulate in the tube body 11 over time. The soil moisture meter 10 can measure the state of soil moisture from the amount of change in the position of the liquid level S, since the thickness (amount) of the air accumulated in the tube body 11 corresponds to the position of the liquid level S.

The magnetic sensor 15 is a member that detects magnetic force. The detection portion of the magnetic sensor 15 extends substantially parallel to the vertical direction of the tube body 11 . The magnetic sensor 15 detects the position of the float member 12 within the tube body 11 by the magnetic force generated by the float member 12. The length of the detection portion of the magnetic sensor 15 in the extending direction is preferably equal to or longer than the length of the region in the vertical direction of the tube body 11 into which the liquid W can enter. According to such a configuration, the magnetic sensor 15 can always detect the position of the float member 12 within the tube body 11 regardless of the position of the liquid level S within the tube body 11, that is, regardless of the position of the float member 12.

In this way, the soil moisture meter 10 can detect the position of the liquid level S, which is the measurement result of soil moisture, by the magnetic force generated by the float member 12. According to such a configuration, the soil moisture meter 10 can detect the position of the liquid level S more accurately and quantitatively than by visual reading. Furthermore, the measurement results obtained by the soil moisture meter 10 can be acquired as electronic data as the measurement values of the magnetic sensor 15. Therefore, it becomes easy to manage the measurement results, and the measurement results can also be used for automating irrigation. Such automation of irrigation will be described below using the irrigation apparatus 1 according to an embodiment of the present invention as an example.

[Irrigation equipment]
(overview)
A irrigation device 1 according to an embodiment of the present invention will be described below with reference to FIGS. 2 and 3. As shown in FIG. 2, the irrigation device 1 according to one embodiment of the present invention includes a soil moisture meter 10, an irrigation pipe 20, and a controller 30. The irrigation device 1 achieves irrigation automation by having the controller 30, which has acquired the measurement results of the soil moisture meter 10, control the opening and closing of the solenoid valves 21 provided in the irrigation pipes 20 according to the measurement results. .

In the irrigation system 1, the soil moisture meter 10 and the controller 30 are connected by wire, and the irrigation pipe 20 and the controller 30 are connected by wire. These wired connections allow the irrigation device 1 to transmit and receive data between the controller 30 and the soil moisture meter 10 or the irrigation pipe 20. According to such a configuration, the soil moisture meter 10 and the irrigation pipe 20 do not need to be provided with a communication device for wireless connection, so the irrigation device 1 can be configured simply and inexpensively.

Further, the connection between the controller 30 and the soil moisture meter 10 or the irrigation pipe 20 may be realized by wireless communication instead of by wire. According to such a configuration, the degree of freedom in installing the controller 30 increases. For example, the controller 30 can be easily installed indoors at a location away from the cultivation site where the soil moisture meter 10 and the irrigation pipe 20 are installed. When the controller 30 is installed indoors, there is no need to consider the water resistance of the controller 30, so that it is easy to use a general-purpose computer or the like as the controller 30, for example.

Furthermore, if the controller 30 can be installed at a location away from the cultivation site, a single controller 30 can be used to centrally control the combinations of soil moisture meters 10 and irrigation pipes 20 installed at multiple cultivation sites. Irrigation can be controlled. In this way, the irrigation device 1 may include a plurality of soil moisture meters 10 and irrigation pipes 20 for one controller 30.

FIG. 3 is a block diagram showing functional blocks of the irrigation device 1. Since the soil moisture meter 10 was explained in the above-mentioned [Soil moisture meter], the explanation will be omitted here.

(Irrigation pipe)
The irrigation pipe 20 is a tubular member through which a liquid such as water or liquid fertilizer passes to irrigate the soil. Holes are formed in the irrigation pipe 20 at predetermined intervals, and when pressure is applied to the liquid in the irrigation pipe 20, the liquid is sprayed from the holes to irrigate the soil. The irrigation pipe 20 is equipped with a solenoid valve 21.

The solenoid valve 21 is a valve that controls the supply of liquid to the irrigation pipe 20. The solenoid valve 21 is configured to be electronically controllable to open and close. When the solenoid valve 21 is opened, liquid is supplied into the irrigation pipe 20, so pressure is applied to the liquid within the irrigation pipe 20. As a result, the liquid is sprayed from the irrigation pipe 20, and the soil is watered.

(controller)
The controller 30 is an electronic device that comprehensively controls the functions of each part of the irrigation device 1. The controller 30 may be a dedicated device for controlling the irrigation device 1, or may be a general-purpose computer such as a PC (Personal Computer). The controller 30 includes a control device 31, a storage device 38, and a communication device 39.

The storage device 38 is a member that stores various information such as setting information of the controller 30 and input information. Examples of the storage device 38 include a HDD (Hard Disk Drive), an SSD (Solid State Drive), and a ROM (Read Only Memory), and may be one of these or a combination of a plurality of them. .

The communication device 39 is a member that communicates with other electronic devices and the like. The communication device 39 may be connected to the Internet, a local communication network, or directly connected to other electronic devices by low power wireless or the like in order to perform communication. .

The control device 31 is a member that centrally controls each part of the controller 30. The control device 31 may be, for example, a CPU (Central Processing Unit). The control device 31 includes a result acquisition section 32 and a determination section 33. Further, the control device 31 may further include at least one of a valve opening/closing section 34, an updating section 35, and a notification section 36.

(Result acquisition part)
The result acquisition unit 32 acquires the detection result of the magnetic sensor 15 included in the soil moisture meter 10 as a measurement result of the soil moisture meter 10. Further, the result acquisition unit 32 calculates the amount of descent of the position of the float member 12 in the soil moisture meter 10 per unit time (hereinafter simply referred to as "the amount of descent") from the acquired detection results of the magnetic sensor 15.

For example, the result acquisition unit 32 acquires all detection results acquired during the current unit time, calculates each value that has decreased from the previous detection result, and calculates an integrated value of the obtained values. In this way, the amount of descent may be calculated. In this case, the result acquisition unit 32 may store the detection result in the storage device 38 every time it acquires the detection result of the magnetic sensor 15. Then, the result acquisition unit 32 may acquire all the detection results acquired during the current unit time from the storage device 38.

Further, the result acquisition unit 32 may store the calculation result in the storage device 38 after calculating the amount of descent. Then, when the result acquisition unit 32 acquires the detection result of the magnetic sensor 15 next time, it acquires the previously calculated amount of descent from the storage device 38, and stores the previous amount of descent in the detection result of the magnetic sensor 15 acquired this time. A value decreased from the detection result may be added. In this case, the result acquisition unit 32 determines whether the amount of descent stored in the storage device 38 is the amount of descent during the current unit time, and performs the above-mentioned addition only if it is determined to be YES. That's fine.

The unit time may be, for example, one day, a period longer than one day, or a period shorter than one day. Here, it is known that the amount of drop in the liquid level S per day on the soil moisture meter 10 is an indicator of the drought stress that crops such as citrus fruits receive (Reference: Kurose et al., Horticultural Research, 15( 2), 139-144, 2016). From the viewpoint of effectively utilizing the knowledge, it is preferable that the unit time is one day.

Further, in calculating the amount of descent, if the position of the float member 12 in the soil moisture meter 10 has increased from the previous detection result, the result acquisition unit 32 does not consider the amount of increase. That is, even when the liquid W is replenished into the pipe body 11 of the soil moisture meter 10, the result acquisition unit 32 may calculate only the amount of descent of the position of the float member 12. Therefore, the result acquisition unit 32 can continuously calculate the amount of descent without being affected by liquid replenishment into the pipe body 11 of the soil moisture meter 10.

It is also known that the integrated value of the amount of decline from the fruit juice accumulation period of a crop until harvest is an indicator of the sugar content of the crop after harvest. From the viewpoint of obtaining an index of the sugar content of crops, the unit time may be a period longer than one day, or the result acquisition unit 32 may further include a function of calculating an integrated value of the amount of decline in a plurality of unit times. may have.

(Judgment Department)
The determination unit 33 determines whether or not to perform irrigation based on the position of the liquid level S in the soil moisture meter 10. Specifically, the determination unit 33 determines that irrigation should be performed when the amount of decline calculated by the result acquisition unit 32 is equal to or greater than a predetermined threshold. The predetermined threshold value may be set as appropriate depending on the characteristics of the soil in which the irrigation device 1 is installed, the characteristics of the crops grown in the soil, and the like.

According to such a configuration, the irrigation device 1 can detect the amount of descent of the position of the float member 12 and determine whether or not to perform irrigation according to the amount of descent. That is, the irrigation device 1 can automatically determine whether or not irrigation is necessary by detecting the amount of decrease in the position of the liquid level S on the soil moisture meter 10, which is an index of the drought stress that crops are subjected to.

(Valve opening/closing part)
The valve opening/closing unit 34 opens the solenoid valve 21 provided in the irrigation pipe 20 for a predetermined time when the determination unit 33 determines that irrigation is necessary. Thereby, liquid is sprayed from the irrigation pipe 20 for a predetermined period of time, and irrigation is performed. The predetermined time may be set as appropriate depending on the characteristics of the soil in which the irrigation device 1 is used and the characteristics of the crops grown in the soil.

In this way, in the irrigation device 1, the controller 30 determines whether or not irrigation is necessary based on the measurement result of the soil moisture meter 10, and when it is determined that irrigation is necessary, performs irrigation from the irrigation pipe 20. Therefore, the irrigation device 1 can accurately grasp the drought stress to which the crops are subjected, and can automatically irrigate the soil according to the drought stress to which the crops are subjected. Therefore, the irrigation device 1 can appropriately control the drought stress that crops are subjected to.

(Update Department)
When the amount of descent calculated by the result acquisition section 32 is equal to or greater than a predetermined threshold, the updating section 35 resets the amount of descent. That is, when the amount of descent is equal to or greater than a predetermined threshold, the controller 30 may determine that the determination unit 33 performs irrigation, and may reset the amount of descent.

The updating unit 35 may reset the amount of decrease by resetting the amount of decrease during the current unit time stored in the storage device 38 to zero, for example. Further, when the result acquisition section 32 calculates the amount of descent each time from a plurality of detection results, the updating section 35 stores information at the time of resetting the amount of descent in the storage device 38. You may go. In this case, the result acquisition unit 32 can use only the values of the detection results after the last reset to calculate the amount of decline.

When the control device 31 includes the updating unit 35, the control device 31 can be reset when the amount of descent of the position of the float member 12 exceeds a predetermined threshold value. Therefore, even if the soil on which the soil moisture meter 10 is installed is very dry and the amount of soil drop greatly exceeds a predetermined threshold, the irrigation device 1 can perform irrigation an appropriate number of times.

(Notification Department)
The notification unit 36 issues a notification when it is determined that the position of the float member 12 is lower than a predetermined position. The notification may be a notification for warning the user of the irrigation device 1, etc. that the amount of liquid W in the pipe body 11 in the soil moisture meter 10 has decreased. The predetermined position may be appropriately set by the user of the irrigation device 1 or the like. The predetermined position may be, for example, approximately half way from the lower end to the upper end of the tubular body 11, or approximately one quarter from the lower end.

Further, the notification unit 36 performs the first notification when determining that the position of the float member 12 is lower than the position approximately half way from the bottom end to the top end of the tube body 11, and sends the first notification approximately four minutes from the bottom end. If it is determined that the position is lower than the position 1, the second notification may be made. In this case, the first notification may be a warning to the user of the irrigation device 1, and the second notification may be a warning. In this way, a plurality of predetermined positions are set, and when the notification unit 36 determines that the position is lower than each predetermined position, it may notify each of the appropriate contents.

The notification by the notification unit 36 may be performed via the communication device 39. For example, the notification unit 36 may send a notification email to the email address of the user of the irrigation device 1 via the communication device 39. Further, the notification unit 36 may notify the slave unit via the communication device 39 using low-power wireless communication. The mode of notification by the notification unit 36 is not limited to this.

According to the configuration in which the control device 31 has the notification unit 36, the control device 31 can notify before the liquid W that has entered the pipe body 11 of the soil moisture meter 10 runs out. Therefore, by receiving the notification, the user of the irrigation device 1 can replenish the liquid W before the liquid W in the pipe body 11 is completely exhausted. Therefore, in the soil moisture meter 10, the state in which the liquid W is always contained in the pipe body 11 is easily maintained, so that the irrigation device 1 can continuously measure the moisture in the soil.

[Irrigation method]
An irrigation method according to an embodiment of the present invention will be described below with reference to FIG. 4. Here, an irrigation method using an irrigation system 1 equipped with a soil moisture meter 10 is illustrated, and a control device 31 executes the main steps. However, the irrigation method according to an embodiment of the present invention is not limited to this, and at least some of the steps may be performed manually or by a device other than the irrigation device 1.

As shown in FIG. 4, first, the result acquisition unit 32 acquires the position of the float member 12 in the soil moisture meter 10 as a detection result of the magnetic sensor 15 (S1). Next, the notification unit 36 determines whether the position of the float member 12 is lower than a predetermined position based on the detection result acquired by the result acquisition unit 32 (S2). If the notification unit 36 determines that the position of the float member 12 is lower than the predetermined position (YES in S2), the notification unit 36 sends a notification that the liquid W in the tube body 11 is decreasing via the communication device 39. Execute (S3).

On the other hand, when the notification unit 36 determines that the position of the float member 12 is equal to or higher than the predetermined position (NO in S2), the notification unit 36 calculates the amount of descent of the position of the float member 12 per unit time (S4). In other words, the result acquisition unit 32 executes a detection step of detecting the amount of descent of the position of the float member 12 per unit time. The method of calculating the amount of descent explained in the above [Irrigation device] is an example of a method of detecting the amount of descent in the detection step. The amount of descent may be detected, for example, by the person implementing the irrigation method checking the detection result of the magnetic sensor 15 multiple times during a unit time and calculating the amount of descent per unit time.

Next, the determination unit 33 determines whether the amount of descent calculated by the result acquisition unit 32 is greater than or equal to a predetermined threshold (S5). If the determination unit 33 determines that the amount of descent calculated by the result acquisition unit 32 is greater than or equal to the predetermined threshold (YES in S5), the determination unit 33 determines to perform irrigation. In response to the determination by the determination unit 33, the valve opening/closing unit 34 opens the solenoid valve 21 for a predetermined period of time (S6). In other words, the determination unit 33 and the valve opening/closing unit 34 execute the irrigation process in which irrigation is performed when the amount of descent is equal to or greater than a predetermined threshold. At this time, the updating unit 35 resets the amount of descent. Then, the control device 31 returns the process to S1.

On the other hand, if the determination unit 33 determines that the amount of descent calculated by the result acquisition unit 32 is lower than the predetermined threshold (NO in S5), the determination unit 33 determines that there is no need to perform irrigation.

Next, the updating unit 35 determines whether or not a unit time has elapsed since the last time the descending amount was reset (S8). When the updating unit 35 determines that a unit time has elapsed since the last time the descending amount was reset (S8: YES), the updating section 35 resets the descending amount (S9). Here, "the time when the descending amount was reset last time" may be either (1) or (2) below;
(1) Last time, when it was determined that the unit time had elapsed and the descending amount was reset,
(2) Regardless of the elapse of unit time, the point in time when the descending amount was last reset.

In the case of (1) above, the updating unit 35 resets the descending amount upon receiving the determination result by the determining unit 33 that the descending amount is equal to or greater than a predetermined threshold before the unit time elapses (in the case of S7 ), the time of the reset is not included in the "time of the previous reset of the descending amount". Therefore, the updating unit 35 can reset the amount of descent every unit time, regardless of whether or not the amount of descent has been reset with the execution of irrigation in the middle of the unit time. Therefore, for example, if the unit time is set to one day, the updating unit 35 can reset the amount of descent at a fixed time every day. Therefore, the control device 31 can easily grasp the amount of descent per day.

On the other hand, as in the case (2) above, the updating unit 35 updates the new information not only at the time when the amount of descent is reset as the unit time passes, but also at the time when the amount of descent is reset due to the execution of irrigation. It may also be the starting point of a unit of time.

The updating unit 35 resets the amount of descent in S9, or returns the process to S1 if it is determined that the unit time has not elapsed since the last time the amount of descent was reset (NO in S8).

Note that although a mode in which the processes S1 to S9 are looped is illustrated here, the control device 31 may terminate the process according to predetermined conditions. The predetermined condition may be, for example, a case where the number of times the updating unit 35 determines that the unit time has elapsed in S8 is equal to or greater than a preset number of times.

[Example of implementation using software]
The control blocks of the control device 31 (particularly the result acquisition unit 32 and the determination unit 33) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software. good.

In the latter case, the control device 31 includes a computer that executes instructions of a program that is software that implements each function. This computer includes, for example, one or more processors and a computer-readable recording medium that stores the above program. In the computer, the processor reads the program from the recording medium and executes the program, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, in addition to "non-temporary tangible media" such as ROM (Read Only Memory), tapes, disks, cards, semiconductor memories, programmable logic circuits, etc. can be used. Further, the computer may further include a RAM (Random Access Memory) for expanding the above program. Furthermore, the program may be supplied to the computer via any transmission medium (communication network, broadcast waves, etc.) that can transmit the program. Note that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[Additional notes]
The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present invention.

1 Irrigation device 10 Soil moisture meter 11 Pipe body 12 Float member 14 Porous cup 15 Magnetic sensor 31 Control device 32 Result acquisition section 33 Judgment section 35 Update section 36 Notification section S Liquid level W Liquid

Claims (4)

A soil moisture meter that has a porous cup at the end of the tube into which the liquid is inserted into the soil, and the position of the liquid level in the tube changes depending on the amount of air that enters the tube from the porous cup. and,
A control device including a determination unit that determines whether or not to perform irrigation based on the position of the liquid level,
The soil moisture meter is
a float member that includes a magnet and floats on the liquid;
a magnetic sensor that detects the position of the float member using magnetic force generated by the magnet;
The control device includes:
a result acquisition unit that calculates the amount of descent of the position of the float member from the detection result of the magnetic sensor ;
further comprising an updating unit that resets the amount of descent when the amount of descent is equal to or greater than a predetermined threshold ;
The determination unit determines that the irrigation is to be performed when the amount of descent is equal to or greater than the predetermined threshold ;
In the irrigation device, the updating unit further resets the descending amount every unit time . The irrigation device according to claim 1 , wherein the control device further includes a notification section that provides notification when it is determined that the position of the float member is lower than a predetermined position. The irrigation device according to claim 1 or 2, wherein the result acquisition unit does not consider an increase in the position of the float member in calculating the amount of descent. A porous cup provided at the end of a tube into which liquid is inserted into the soil, a float member containing a magnet and floating on the liquid, and a magnetic sensor that detects the position of the float member using magnetic force generated by the magnet. An irrigation method using a soil moisture meter, wherein the position of the liquid level in the tube changes depending on the amount of air entering the tube from the porous cup,
a detection step of detecting the amount of descent of the position of the float member;
an irrigation step in which irrigation is performed when the amount of decline is equal to or greater than a predetermined threshold;
a first updating step of resetting the amount of decrease when the amount of decrease is equal to or greater than the predetermined threshold;
An irrigation method comprising : a second updating step of resetting the amount of decline every unit time .

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