JP6443788B2 - Automatic irrigation system, automatic irrigation method, program, controller for automatic irrigation - Google Patents

Description

  The present invention relates to an automatic irrigation system for automatically irrigating a field from a water supply device, an automatic irrigation method for automatically irrigating a field, a program for causing a computer to execute this automatic irrigation method, and an automatic irrigation system for controlling a water supply device It relates to the controller.

  Conventionally, in order to automatically supply water to plants and the like, a technique for starting water supply when water shortage of a water supply target is detected is known (for example, see Patent Document 1). The automatic water supply system described in Patent Document 1 supplies water so that the water supply target does not run out of water while supplying water at predetermined time intervals.

JP 2003-102295 A

  Since the technique described in Patent Document 1 determines the amount of water based on the output of the sensor and replenishes the water when it is determined that the water is insufficient, the determination is made depending on the position of the sensor and the characteristics of the soil. Variations can occur. In particular, since soil characteristics are not taken into account, when water is supplied to a plant, there is a problem that the amount of water in the soil with respect to the plant tends to be excessive or insufficient.

  Now, when the soil layer for plant growth is formed on the gravel layer, the state where moisture penetrates the entire soil layer and moisture does not reach the gravel layer is the ideal state. To do. In the technique described in Patent Document 1, even if moisture is detected by the sensor, it cannot be determined whether moisture has penetrated only the soil formation layer or moisture has reached the gravel layer. There is a problem that it cannot be judged whether the amount is excessive or insufficient.

  An object of the present invention is to provide an automatic irrigation system and an automatic irrigation method that suppress the excess and deficiency of the moisture content in the soil in consideration of soil characteristics, and further, a program for causing a computer to execute the automatic irrigation method And an automatic irrigation controller for controlling a water supply device.

The automatic irrigation system according to the present invention includes a pF meter that measures a pF value of a specific depth of a soil formation layer in a field, a water supply device that irrigates the field, and just before irrigation from the water supply device to the field. The pF value measured by the pF meter is acquired, an irrigation amount determination unit that determines an appropriate amount of water to be irrigated in a unit period from the pF value, and an amount of water determined by the irrigation amount determination unit is irrigated to the field And a control device that controls the water supply device, and the irrigation amount determination unit includes a conversion table in which a pF value and an appropriate amount of water to be irrigated in a unit period are associated with each other according to the soil quality of the field. The pF value measured by the pF meter is collated with the conversion table to determine the amount of water, and the appropriate amount of water is the amount of water that penetrates the entire soil formation layer without excess or deficiency. It is characterized by that .

  In this automatic irrigation system, it is preferable that the conversion table is divided into a plurality of stages according to the growth process of the plant, and the amount of water to be irrigated is determined for each divided stage.

  In this automatic irrigation system, it is preferable to further include a display for displaying the conversion table.

  In this automatic irrigation system, it is preferable to further include an operating device for changing the amount of water in the conversion table.

In this automatic irrigation system, the conversion table, the type of plant, depending on growing purposes, correspondence between the pF value and quantity are provided a plurality of types having different, the conversion table in which the irrigation amount determining unit is employed It is preferable to select from the plurality of types.

The automatic irrigation method according to the present invention includes a step of acquiring a pF value of a specific depth of the soil layer in the field measured by a pF meter immediately before irrigating the field using a water supply device, and determining a irrigation amount Determining the amount of water to be irrigated by comparing the pF value acquired by the unit from the pF meter with a conversion table in which an appropriate amount of water to be irrigated in a unit period is associated with a pF value according to the soil quality of the field And a control device that controls the water supply device so as to irrigate the field with the water amount determined by the irrigation amount determination unit , and the appropriate water amount is sufficient for the entire soil formation layer. water and wherein the amount of water der Rukoto to penetrate.

The program according to the present invention includes a step of acquiring a pF value of a specific depth of a soil formation layer in the field measured by a pF meter immediately before irrigating the field using a water supply device, and a irrigation amount The determination unit determines the amount of water to be irrigated by comparing the pF value acquired from the pF meter with a conversion table in which an appropriate amount of water to be irrigated in a unit period is associated with a pF value according to the soil quality of the field. And the control device controls the water supply device to irrigate the field with the amount of water determined by the irrigation amount determination unit , and the appropriate amount of water exceeds the entire soil formation layer. shortage without water and wherein the amount of water der Rukoto to penetrate.

The controller for automatic irrigation according to the present invention is a controller used together with a pF meter for measuring a pF value of a specific depth of a soil layer in a field and a water supply device for irrigating the field, from the water supply device The irrigation amount determination unit that acquires the pF value measured by the pF meter immediately before irrigating the field, determines an appropriate amount of water to be irrigated in a unit period from the pF value, and the water amount determined by the irrigation amount determination unit And a control device that controls the water supply device to irrigate the field, and the irrigation amount determination unit associates a pF value corresponding to the soil quality of the field with an appropriate amount of water to be irrigated in a unit period. comprising a conversion table which is formed of the pF value which the pF meter measured to determine the amount of water by collating the conversion table, the proper amount of water, just enough water to the whole of the plow layer Characterized in that it is a volume of water to penetrate.

According to the configuration of the present invention, by using a conversion table that associates the proper amount of water irrigating the characteristic pF value and unit period taking into account the soil in the field, to determine the amount of water with respect to the measured pF value Since the structure is adopted and the characteristics of the soil are reflected in the conversion table, it is possible to suppress the excess and deficiency of the moisture content in the soil in consideration of the characteristics of the soil.

It is a block diagram which shows embodiment. It is a figure which shows an example of the conversion table used for the same as the above. It is a figure which shows the other example of the conversion table used for the same as the above. It is a figure which shows the further another example of the conversion table used for the same as the above. It is a figure which shows another example of the conversion table used for the same as the above. It is a figure which shows the step of the growth process of a plant. It is the schematic which shows the structural example of a pF meter in the same as the above. It is sectional drawing which shows the structure of the agricultural field using the same as the above. It is a figure which shows the example of simulation of irrigation.

As shown in FIG. 1, the automatic irrigation system irrigates the field with a pF meter 20 that measures a pF value related to the moisture content of the soil in the field, a water supply device 30 that irrigates the field, and a water supply device 30. And a control device 14 for controlling the amount of water. The control device 14 irrigates the soil in the field according to the amount of water determined by the irrigation amount determination unit 11.

  The field is assumed to be an indoor field such as in an agricultural house, but the technical idea described below using the embodiment may be applied to an outdoor field depending on conditions. The amount and timing of irrigation varies depending on the type of plant to be cultivated in the field and the purpose of cultivating the plant, so that a field is provided for each type of plant and the purpose of cultivating, and the amount and timing of irrigation are adjusted for each field. It is desirable. Here, the purpose of breeding means, for example, increasing the size of the harvest, increasing the sugar content, and increasing the concentration of useful components.

  The plants to be grown are assumed to be soft vegetables such as spinach, komatsuna, and mizumina. Even if it exists, the technical idea demonstrated below is applicable.

Since use of pF meter 20, without requiring skill of the user, simple and Ru can der be measured accurately pF value. The embodiments described below are, pF meter 20 as a simple example will be described for the case of one, it may be arranged a plurality of pF meter 20 at a plurality of locations of the field.

  The water supply device 30 is assumed to have a configuration including a submerged tube in which a large number of minute submerged holes are formed on the tube wall of the tube through which water passes, but this configuration is not intended to limit the configuration. For example, it is possible to use a watering device such as a sprinkler, or to use a mist tube provided with a number of nozzles for ejecting mist to the tube through which water flows. Further, these water supply devices 30 can be used in appropriate combinations. In the case where the water supply device 30 includes a flooding tube or a mist tube, the water supply device 30 also includes a water supply pump for pressurization, an electromagnetic valve for selecting water discharge and stop, and the like.

The pF meter 20 gives a pF value to the irrigation amount determination unit 11 via an interface unit (hereinafter referred to as “I / F unit”) 15. Further, the water supply device 30 is connected to the control device 14 via the I / F unit 16. The I / F unit 15 transfers data from the pF meter 20 to the irrigation amount determination unit 11. The I / F unit 16 includes an electromagnetic contactor (a kind of electromagnetic relay) housed in a control panel, and supplies water to the water supply device 30 by opening and closing the electromagnetic contactor according to an instruction from the control device 14. Controls power supply to pumps and solenoid valves.

The irrigation amount determination unit 11 includes a verification unit 111 and a conversion table 112. The collating unit 111 collates the pF value of the soil measured by the pF meter 20 with the conversion table 112, and converts the pF value into the amount of water to be irrigated per unit period. Here, conversion table 112, as shown in FIG. 2, the pF value that put the soil before irrigation, appropriate amount of water irrigation per unit period (1 day) (rainfall) and the association is stored ing. Therefore, the collating unit 111 extracts an appropriate amount of water by collating the pF value measured by the pF meter 20 with the pF value of the conversion table 112. A technique for creating the conversion table 112 will be described later.

Since the amount of water extracted by the verification unit 111 is the amount of water per unit period and does not reflect the size of the field, the irrigation amount determination unit 11 multiplies the amount of water extracted by the verification unit 111 by the area of the field. To calculate the appropriate amount of water. That is, when the amount of water extracted by the collating unit 111 is Q [mm] and the area of the field is S [m ² ], the irrigation amount determination unit 11 determines the appropriate amount of water to be irrigated per day as QS [ Liter].

When the irrigation amount determination unit 11 determines the amount of water to be irrigated in the unit period as described above, the determined amount of water is instructed to the control device 14, and the control device 14 supplies water so as to irrigate the field with the instructed amount of water. The device 30 is controlled.

By the way, the appropriate amount of water to be irrigated in a unit period varies depending on the nature of the soil in the field. Since the pF value represents the force for separating the moisture adsorbed on the soil, the pF value decreases when the soil is wet, and the pF value increases when the soil is dry. However, since the water retention capacity of the soil cannot be determined even if the pF value is measured, the next irrigation timing and amount of water cannot be estimated only by the pF value. That is, since the time change of the pF value of the soil after irrigation is not reflected in the pF value, the timing and amount of the next irrigation cannot be determined only by the pF value.

  When performing automatic irrigation using a pF value from the above-mentioned circumstances, the pF value is monitored, water supply is started when the pF value becomes equal to or higher than the first threshold value, and water is supplied until the pF value becomes equal to or lower than the second threshold value. It is considered. However, if this technique is employed, useless power is consumed to keep monitoring the pF value.

However, water retention of soil is represented by the moisture characteristic curve is a relationship between the body volume water content and matric potential of the soil. Therefore, if the water characteristic curve is known together with the pF value of the soil to be irrigated, the amount of water at the next irrigation can be estimated. Therefore, the conversion table 112 is created so as to reflect the moisture characteristic curve of the soil in the field. That is, a test for obtaining a moisture characteristic curve of soil in the field is performed in advance, and the conversion table 112 is created based on the moisture characteristic curve. In other words, the conversion table 112 contains information on the moisture characteristic curve, and the amount of water suitable for irrigation considering the water retention capacity of the soil only by comparing the pF value measured by the pF meter 20 with the conversion table 112. Is extracted.

Here, in this embodiment, the timing for measuring the pF value of the soil is every fixed time determined by the irrigation amount determination unit 11, and the pF value of the soil is acquired from the pF meter 20 immediately before irrigation. . That is, irrigation is performed at regular intervals, and the amount of water at the time of irrigation is determined using the water content measured immediately before irrigation. Thus, the I / F unit 15 acquires the pF value from the pF meter 20 at regular intervals, and delivers the acquired pF value to the verification unit 111. The verification unit 111 extracts the amount of water from the conversion table 112. Finally, the amount of water to be irrigated in the field is determined.

In the above-described example, it is assumed that the irrigation is performed once a day with a certain time being one day. However, the conversion table 112 may be created so that the irrigation is performed a plurality of times a day. Is possible. In this way, irrigation is performed periodically, and the amount of water in the field is appropriately maintained by adjusting the amount of water every time irrigation is performed, so there is no need to continue monitoring the pF value of the soil, and the pF value of the soil The power used for the measurement is reduced. Moreover, since the conversion table 112 is created in consideration of the amount of water retained in the soil, there is no excess or deficiency in the amount of water during irrigation while irrigating regularly.

  By the way, there is a possibility that a change occurs in the moisture characteristic curve of the soil during the period of plant growth, and it may be necessary to change the amount of water at one irrigation depending on the type of plant and the purpose of breeding. There is. Therefore, a plurality of types of conversion tables 112 having different correspondences between pF values and water amounts are provided for the same moisture characteristic curve. In order to be able to select the conversion table 112 used by the irrigation amount determination unit 11 from among the plurality of types of conversion tables 112, a selection unit 13 operated by the user is provided. That is, the conversion table 112 can be selected from a plurality of types by the user operating the selection unit 13.

  The selection unit 13 includes a display 131 that displays options of the conversion table 112 and an operation device 132 that enables a user to perform a selection operation. The selection unit 13 is configured such that a desired conversion table 112 is selected when the user operates the operation device 132. In addition, as for the indicator 131, as for the option mentioned above, it is desirable to display the word which represents the kind of plant and the breeding purpose.

  The display 131 and the operation unit 132 are preferably configured using a flat panel display such as a liquid crystal display and a touch panel overlaid on the screen of the display 131. When this structure is adopted for the selection unit 13, it is easy to take measures against drip-proofing and dust-proofing that are required when used in a field.

  The display 131 can display the contents of the conversion table 112. The operation device 132 can be used for the purpose of changing the contents of the conversion table 112 together with the display device 131. The function of changing the conversion table 112 will be described later.

  The conversion table 112 shown in FIG. 2 shows the simplest example in order to simplify the explanation, but the actual conversion table 112 adopts one of the formats of FIG. 3, FIG. 4, and FIG. The 3, 4, and 5, the unit is represented by [t] in consideration of the area of the field. 1 [t] may be converted into 1000 [liters].

3, 4, the conversion table 112 shown in FIG. 5, the amount of water to irrigation for the pF value of the previous irrigation soil, are determined for each stage of division in accordance with the growth process of plants. For example, in the case of spinach, the stage of the plant growth process is from sowing to germination, from germination to development of four true leaves, from development of four true leaves to plant height 20 cm, from plant height 20 cm, as shown in FIG. Divided into 4 stages until harvest. Other plants are generally the same, and are divided into a period until germination, a period until photosynthesis becomes active, a period in which both the above-ground part and the underground part grow, and a period until harvest. Hereinafter, the respective stages are referred to as stage 1, stage 2, stage 3, and stage 4.

  After sowing, initial irrigation (initial irrigation) is performed to promote germination. After the initial irrigation, the amount of irrigation to be added is determined according to whether the stage 1, stage 2, stage 3, or stage 4 is selected. The amount of water in each stage is the maximum in stage 3, then in order of stage 1 and stage 2, and stage 4 is the minimum. If the amount of water at each stage is expressed in the form of the amount of water (stage), the relationship of water volume (stage 3)> water volume (stage 1)> water volume (stage 2)> water volume (stage 4) is established. If a to d shown in FIG. 3 are water values, c> a> b> d.

In the conversion table 112 shown in FIG. 3, a threshold value is set for the pF value, and the amount of water is set according to whether the pF value measured by the pF meter 20 is equal to or greater than the threshold value or less than the threshold value. In the illustrated example, the threshold value for the pF value is 2.0, and 2.0 or higher is classified as “dry”, and less than 2.0 is “wet”, and when it is wet, irrigation is not performed. . In FIG. 3, “OFF” in the initial irrigation item indicates that irrigation is not performed, and “ON” indicates that irrigation is performed.

Thus, the conversion table 112 for dividing the pF value into two regions is used when the analog pF meter 20 is used. As shown in FIG. 7, the analog pF meter 20 indicates the pF value at the position of the movable needle 21, and can represent the threshold value by the position of the fixed needle 22. The pF meter 20 turns on the contact output when the movable needle 21 becomes equal to or greater than the value indicated by the fixed needle 22. The illustrated example shows a case where the pF value at a depth of 10 cm from the surface of the soil layer 1 is measured. The number of fixed needles 22 is not limited to one, and a pF meter 20 including a plurality of fixed needles 22 may be used.

The conversion table 112 shown in FIG. 4 corresponds to the pF meter 20 that can output the pF value in increments of 0.1. This type of pF meter 20 is a digital type and employs, for example, a configuration that measures the dielectric constant of soil and converts it into a pF value . In the illustrated example, one region is assigned to one pF value, a pF value of 1.6 to 2.1 is determined to be wet, and a pF value of 2.2 to 2.8 is determined to be dry. In this example, since the pF value is divided into 13 regions by 0.1, the amount of irrigation water is divided into 65 patterns (5 stages × 13 regions). By using this conversion table 112, it is possible to precisely adjust the amount of irrigation water. In the illustrated example, the case where the pF value is 2.1 or less is classified as “wet”, and the case where it is 2.2 or more is classified as “dry”.

The conversion table 112 shown in FIG. 5 is the same as the conversion table 112 shown in FIG. 4 and corresponds to the pF meter 20 that can divide the pF value in increments of 0.1. However, instead of assigning one area to one pF value as in the conversion table 112 shown in FIG. 4, one area is represented by a range of pF values as in the conversion table 112 shown in FIG. 3. . The classification of “wet” and “dry” is the same as in the conversion table 112 shown in FIG. 4, but the region has a pF value of less than 1.6, 1.6 to 1.8, 1.9 to 2. It is classified into six types of 1, 2.2 to 2.4, 2.5 to 2.7, and more than 2.7. Therefore, the amount of irrigation is divided into 30 types (5 stages × 6 areas).

3, FIG. 4, if the conversion table 112 shown in FIG. 5 is prepared, in accordance with the performance of pF total of 20 kinds or pF meter 20, it should be able to distinguish the conversion table 112, various pF meter 20 can be used in combination.

  Furthermore, since this embodiment is periodically irrigated, if the amount of water evaporation varies depending on the temperature, the amount of water during irrigation may be excessive or insufficient. Therefore, it is desirable that the irrigation cycle is relatively short. Moreover, you may make it possible to change the cycle of irrigation according to the kind of plant to grow and the breeding purpose.

Among the configurations described above, the configuration (the configuration surrounded by a square) excluding the pF meter 20 and the water supply device 30 constitutes the automatic irrigation controller 10. The automatic irrigation controller 10 is realized by executing a program that realizes the above-described functions using a personal computer or an embedded computer as hardware elements. In addition, when using an electromagnetic contactor for the I / F unit 16, the I / F unit 16 is required separately from the computer. When using an embedded computer, the selection unit 13 including the display 131 and the operation device 132 is necessary separately from the embedded computer.

The program causes the computer to execute the following steps. That is, the step of acquiring the pF value of the soil from the pF meter 20 is executed immediately before instructing the water supply device 30 to irrigate the field at regular intervals. Next, the step of collating the pF value acquired by the irrigation amount determining unit 11 from the pF meter 20 with the conversion table 112 and determining the amount of water to be irrigated is executed. Further, a step is executed in which the control device 14 controls the water supply device 30 so as to irrigate the field with the amount of water determined by the irrigation amount determination unit 11.

  By the way, the conversion table 112 described above is created by performing a computer simulation. Hereinafter, a computer simulation for creating the conversion table 112 will be briefly described. In the computer simulation, the soil in the field is assumed to have the structure shown in FIG. The soil includes two layers, a soil layer 1 in which plant roots grow and a gravel layer 2 formed as a lower layer of the soil layer 1 in order to promote the discharge of excess water. In irrigation, the state where water has penetrated the entire soil layer 1 is regarded as an ideal state, and the state where water has permeated into the gravel layer 2 is regarded as an excessive water state. The state where it has not been considered is a state of lack of moisture.

  It is assumed that the creation of the conversion table 112 is not performed by a user who uses the automatic irrigation system, but by a manufacturer who provides the automatic irrigation system. This is because the simulation requires a moisture characteristic curve, which will be described later, but a general user who uses the automatic irrigation system cannot obtain the moisture characteristic curve. Therefore, to create the conversion table 112, a soil sample received from a user who uses the automatic irrigation system is required. As a soil sample for obtaining a moisture characteristic curve, for example, a sampler such as a sample cylinder is used to collect soil having a ground surface, a depth of 10 cm, and a depth of 20 cm from one or more places.

As described above, since the conversion table 112 that varies depending on the water retention capacity of the soil is necessary, a moisture characteristic curve is first obtained for the soil. That is, the collected soil is measured for the physical properties (water retention, water permeability) of the soil using a plurality of known methods, and a moisture characteristic curve is obtained from the measurement result. Further, based on the information obtained from the obtained moisture characteristic curve, the maximum theoretical water content of the sample soil is obtained. By performing various simulations by giving various initial values to the water content, the required amount of irrigation is determined for each initial value. If the moisture characteristic curve is known for the soil of interest, the step of obtaining the moisture characteristic curve can be omitted. The moisture characteristic curve is obtained by a well-known method using a soil sample. The moisture characteristic curve used here means a moisture characteristic curve representing the relationship between the pF value and the pressure head.

Next, the pF value of the soil sample is measured using a pF meter using the same principle as the pF meter 20 described above, and the measured pF value is fitted to the moisture characteristic curve, so that the pF value is set to the pressure head. Convert. When the converted pressure head and moisture characteristic curve are used, it is possible to perform a simulation on the temporal change of the pF value in the soil.

  In the computer simulation, a plurality of types of conditions with different initial moisture contents of the soil are set, and the temporal change in volumetric water content when the initial irrigation water quantity is varied for each condition is calculated. FIGS. 9A and 9B show examples of simulations when the initial water content is the same and the initial watering amount is different. The example of FIG. 9A shows a case where the amount of initial irrigation is large compared to the example of FIG. 9B. Moreover, the characteristic represented by the number in parentheses in FIG. 9 represents the change characteristic of the volumetric water content for every depth of 10 cm. Characteristic (1) is the surface of soil layer 1 (see FIG. 8), characteristic (2) is -10 cm, characteristic (3) is -20 cm, characteristic (4) is -30 cm, characteristic (5) is -40 cm, characteristic (6) corresponds to −50 cm, respectively. Characteristic (5) and characteristic (6) correspond to the gravel layer 2.

As can be seen from FIG. 9, the initial watering amount is not greatly related to the volumetric water content in the vicinity of the surface of the soil layer 1 , but the region about 20 cm deep from the surface of the soil layer 1, and the soil It is relatively involved in the volumetric water content with the region having a depth of 40 cm or more from the surface of the layer 1. Therefore, in a plant whose root depth reaches about 20 cm from the surface of the soil formation layer 1 like a general soft vegetable, it is expected that the amount of initial irrigation affects the growth.

  The initial moisture amount and the initial irrigation amount may be input by the operator when performing a simulation for creating the conversion table 112. However, if the number of combinations is to be increased, the conditions are automatically set by the application program for simulation. Can be generated.

By the above-described simulation, a change in the volumetric water content in the soil with the passage of time is obtained using the measurement items (moisture characteristic curve and pF value ) actually measured on the soil sample in the field and the irrigation water amount as input conditions. In this way, the temporal change of the volume moisture content is obtained by simulation under the condition of various combinations of initial water content and initial watering amount. From the obtained results, it is possible to determine the relationship between the initial water amount ( pF value ) and the amount of water for irrigation so as to remain in the soil formation layer 1 for a long period of time (for example, 25 days) after irrigation. become. That is, it is possible to create the conversion table 112 in which the amount of irrigation is associated with the pF value of the soil. By using this conversion table 112, it is possible to determine the amount of water that is not excessive or insufficient when irrigating regularly.

  In addition, when performing additional irrigation, paying attention to the depth according to the type of plant, the time when the volumetric water content falls below the threshold at the focused depth is estimated from the simulation results, and the pF value is estimated at the estimated time. You may make it perform irrigation so that it may become a predetermined value. For example, when the plant is spinach, paying attention to the depth of −20 cm in the simulation result selected for the creation of the conversion table 112, the pF value is 1 at the time when the volume content of this depth is less than or equal to the threshold value. What is necessary is just to determine the amount of irrigation so that it may become .6.

  By the way, as described above, the selection unit 13 includes the display unit 131 and the operation unit 132, and the conversion unit 112 can be displayed on the display unit 131. If the display device 131 is used only for confirming the contents of the conversion table 112, the operation device 132 provided in the selection unit 13 only needs to have the function of selecting the conversion table 112.

  On the other hand, the operation device 132 may be configured to allow each value of the conversion table 112 displayed on the display device 131 to be changed. For example, when the operation device 132 is a touch panel, only a value corresponding to a desired value of the conversion table 112 displayed on the display device 131 is changed by continuing to press for a predetermined time (so-called long press). to enable. Alternatively, a value corresponding to the corresponding item can be obtained by long-pressing a part corresponding to one item classified by the pF value in the conversion table 112 or an item corresponding to one stage of the plant growth process. It becomes possible to change all at once.

  As described above, by allowing the user to change the value of the conversion table 112, even if the conversion table obtained from the measurement items actually measured for the soil in the field is deviated from the actual characteristics of the field. It becomes possible to perform correction so as to obtain an appropriate amount of water.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made according to design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it can be changed.

DESCRIPTION OF SYMBOLS 10 Controller for automatic irrigation 11 Irrigation amount determination part 13 Selection part 14 Control apparatus 20 pF meter 30 Water supply apparatus 111 Collation part 112 Conversion table 131 Display device 132 Operator

Claims (8)

A pF meter for measuring a pF value at a specific depth of the soil layer in the field;
A water supply device for irrigating the field;
An irrigation amount determination unit that acquires the pF value measured by the pF meter immediately before irrigating the field from the water supply device, and determines an appropriate amount of irrigation per unit period from the pF value;
A controller for controlling the water supply device so as to irrigate the field with the amount of water determined by the irrigation amount determination unit;
The irrigation amount determination unit includes a conversion table in which a pF value is associated with an appropriate amount of water to be irrigated in a unit period according to the soil quality of the field, and the pF value measured by the pF meter is the conversion table. The automatic irrigation system is configured to determine the amount of water with reference to the above, and the appropriate amount of water is the amount of water that penetrates the entire soil formation layer without excess or deficiency.   The conversion table is divided into a plurality of stages according to the growth process of the plant, and the amount of water to be irrigated is determined for each divided stage.
  The automatic irrigation system according to claim 1.   A display for displaying the conversion table is further provided.
  The automatic irrigation system according to claim 1 or 2.   An operation device for changing the amount of water in the conversion table is further provided.
  The automatic irrigation system according to claim 3.   The conversion table is provided with a plurality of types in which the correspondence relationship between the pF value and the amount of water differs according to the type of plant and the purpose of growing, and the conversion table used by the irrigation amount determination unit is selected from the plurality of types. The automatic irrigation system according to any one of claims 1 to 4.   Obtaining a pF value of a specific depth of the soil layer in the field measured by a pF meter immediately before irrigating the field using a water supply device;
  The amount of water to be irrigated by collating the pF value acquired by the irrigation amount determination unit from the pF meter with a conversion table in which an appropriate amount of water to be irrigated in a unit period is associated with a pF value according to the soil quality of the field. A step to determine;
  The controller controls the water supply device to irrigate the field with the amount of water determined by the irrigation amount determination unit,
  The appropriate amount of water is the amount of water that penetrates the entire soil layer without excess or deficiency.
  An automatic irrigation method characterized by that.   On the computer,
  Obtaining a pF value of a specific depth of the soil layer in the field measured by a pF meter immediately before irrigating the field using a water supply device;
  The amount of water to be irrigated by collating the pF value acquired by the irrigation amount determination unit from the pF meter with a conversion table in which an appropriate amount of water to be irrigated in a unit period is associated with a pF value according to the soil quality of the field. A step to determine;
  The controller controls the water supply device to irrigate the field with the amount of water determined by the irrigation amount determination unit, and
  The appropriate amount of water is the amount of water that penetrates the entire soil layer without excess or deficiency.
  A program characterized by that.   A controller used with a pF meter for measuring a pF value of a specific depth of a soil layer in a field, and a water supply device for irrigating the field,
  An irrigation amount determination unit that acquires the pF value measured by the pF meter immediately before irrigating the field from the water supply device, and determines an appropriate amount of irrigation per unit period from the pF value;
  A controller for controlling the water supply device so as to irrigate the field with the amount of water determined by the irrigation amount determination unit;
  The irrigation amount determination unit includes a conversion table in which a pF value corresponding to the soil quality of the field and an appropriate amount of water to be irrigated in a unit period are associated, and the pF value measured by the pF meter is stored in the conversion table. It is comprised so that a water amount may be collated and the said appropriate water amount is a water amount which water permeate | transmits without excess and deficiency to the whole said soil layer
  A controller for automatic irrigation.

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