JP2019052910A - Evaporation potential measuring device - Google Patents

Abstract

To provide an evaporation potential measuring device with which it is possible to accurately measure evaporation potential.SOLUTION: The evaporation potential measuring device comprises: a water tank 1 for storing water; a porous medium 5 having an immersion part 2 immersed in water stored in the water tank 1 and an evaporation part 3 stretched in the air; and a water amount detection mechanism 8 for detecting the amount of water taken in and out of the water tank 1. The porous medium 5 comes in shape of a sheet, includes a connecting part 4 for connecting between the immersion part 2 and the evaporation part 3 and can further include a holding member 6 disposed above the water tank 1 and covering both faces of the connecting part 4 and supporting an end of the evaporation part 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an evaporation potential measuring apparatus.

  In recent years, attempts have been made to industrialize agriculture by, for example, automatically controlling irrigation (watering), fertilization, and the like to improve the yield and quality of crops. When automating irrigation and fertilization, hydroponic cultivation using a cultivation solution in which fertilizer is mixed with irrigation water without using soil is suitable. Examples of the hydroponics include hydroponics that does not use a solid medium, and solid medium culture that uses a limited medium in which a medium such as sand, rock wool, or coconut shell is filled in a relatively small-capacity container. Compared to hydroponics, solid medium culture can supply air to the roots of the crops, making it easier to maintain the crops healthy, adjusting the water content of the medium according to the degree of crop growth, It is considered promising that crops can be cultivated more efficiently.

  Irrigation and fertilization are required to be performed according to the degree of crop growth. As an index of the degree of growth of the crop, the amount of water evaporated from the crop can be considered. Crop mainly evaporates water from the leaves, but the amount of leaves increases as the crop grows, and the amount of water evaporation increases proportionally. The amount of water stored inside the crop increases with the growth of the crop, but it is very small compared to the amount of water evaporated from the crop, so by detecting the amount of water absorbed by the crop from the root, It is possible to grasp the amount of water evaporation.

  The amount of water evaporated from a crop is affected not only by the degree of growth of the crop but also by temperature, humidity, airflow (wind), sunlight, and the like. For this reason, the growth degree of a crop cannot be accurately grasped only by the amount of water absorbed from the root of the crop. Therefore, it is required to quantify the easiness of evaporation of water from crops (referred to as evaporation potential) in consideration of the effects of temperature, humidity, airflow, sunlight, and the like. Although it is possible to individually detect the temperature, humidity, wind speed, amount of sunlight, etc. with a sensor, the leaf surface has a boundary layer (in hydrodynamics), and the air in the vicinity of the leaf surface that is actually involved in evaporation It is not easy to measure the temperature, humidity, and wind speed accurately. Further, since the evaporation potential has multiple collinearity in which these are intertwined in a complicated manner, it cannot be easily quantified from the measured values of each sensor.

  As a device for directly measuring the amount of transpiration (evaporation amount) from a leaf of a crop, a sensor for directly detecting the amount of water vapor evaporated from the leaf by attaching a water vapor sensor to the back side of the leaf of the crop has been proposed (Japanese Patent Application Laid-Open (JP-A)). 2006-214858). The water vapor sensor described in this publication is formed by adsorbing a semiconductor material on the pore walls of a porous thin film in order to reduce the influence on the transpiration rate. Such an evaporation sensor can measure the evaporation potential indicating the degree to which the environment such as the temperature affects the evaporation of water from the crop because the measured value changes when the crop is wilted. It is not a thing.

  As an apparatus for measuring the evaporation potential, there is an evaporation pan used in the field of climatology. The evaporating dish is intended to measure changes in the local climate on a daily and monthly basis, and compensates for environmental effects such as sunshine on the amount of water absorbed from the roots of the crop to understand the degree of crop growth. The unit time of measurement is too long to use.

JP 2006-214858 A

  The water vapor sensor disclosed in the above publication suppresses the influence of the sensor mounting on the evaporation amount by using a porous body, but particularly suppresses the influence of wind and direct sunlight. May not be able to be measured.

  This invention is made | formed based on the above situations, and makes it a subject to provide the evaporation potential measuring apparatus which can measure an evaporation potential correctly.

  An evaporation potential measuring device according to an aspect of the present invention made to solve the above problems includes a water tank for storing water, an immersion part immersed in water stored in the water tank, and an evaporation part stretched in the air. And a porous body having a water amount detection mechanism for detecting the amount of water entering and exiting the water tank.

  The evaporation potential measuring device according to one embodiment of the present invention can accurately measure the evaporation potential.

FIG. 1 is a schematic cross-sectional view showing an evaporation potential measuring apparatus according to an embodiment of the present invention.

[Description of Embodiment of the Present Invention]
An evaporation potential measuring device according to an aspect of the present invention includes a water tank for storing water, a porous body having an immersion part immersed in water stored in the water tank and an evaporation part stretched in the air, and the water tank. A water amount detection mechanism for detecting the amount of water entering and exiting.

  In the evaporation potential measuring device, the porous body sucks up water in the water tank from the immersion part and evaporates water from the evaporation part to the air according to the environment in the same manner as the leaves of the plant. By detecting the amount of water that enters and exits, the evaporation potential can be measured relatively accurately.

  In the evaporation potential measuring apparatus, the porous body has a sheet shape, and has a connection part that connects the immersion part and the evaporation part, and is disposed on the water tank. It is preferable to further include a holding member that covers and supports the end portion of the evaporation portion. Thus, the porous body has a sheet-like shape and has a connection part for connecting the immersion part and the evaporation part, the evaporation potential measuring device is disposed on the water tank, and the connection part By further including a holding member that covers both sides of the substrate and supports the end of the evaporation unit, the distance between the immersion unit and the evaporation unit can be arbitrarily set. Thus, the evaporation potential measuring device can be designed so that the evaporation amount of water from the evaporation section is closer to the evaporation amount from the leaves of the crop to be cultivated. Can be measured.

  In the evaporation potential measuring apparatus, it is preferable that the water tank has a cover plate that covers the upper surface of the water surface, and the holding member protrudes from the cover plate. As described above, the water tank has a cover plate that covers the upper surface of the water surface, and the holding member protrudes from the cover plate, thereby suppressing evaporation of water directly from the water surface of the water tank into the air. The measurement accuracy can be improved.

  In the evaporating potential measuring apparatus, it is preferable that the evaporating part is held in parallel with the water surface of the water tank, and an average distance between the evaporating part and the lid plate is 0.1 cm or more and 50 cm or less. As described above, the evaporation unit is held parallel to the water surface of the aquarium, and the average distance between the evaporation unit and the cover plate is within the above range. You can get closer.

  In the evaporation potential measuring apparatus, it is preferable that the water tank and the holding member have light reflectivity. As described above, since the water tank and the holding member have light reflectivity, the water tank and the holding member are more reliably prevented from evaporating, and the water tank and the holding member are heated by sunlight to excessively increase the evaporation amount. Can be prevented.

  The evaporation potential measuring device further includes a water supply mechanism for supplying water to the water tank so that the water level of the water tank is kept constant, and the water amount detection mechanism detects a water supply amount from the water supply mechanism to the water tank. preferable. Thus, by further providing a water supply mechanism for supplying water to the water tank so as to keep the water level of the water tank constant, fluctuations in the water supply capacity to the evaporation part of the connection part can be prevented, and the amount of water Since the detection mechanism detects the amount of water supplied from the water supply mechanism to the water tank, the amount of water can be detected relatively accurately, so that the evaporation potential can be measured more accurately.

  In the evaporating potential measuring apparatus, it is preferable that the porous body has a water absorption property capable of maintaining the water content of the evaporating part at 50% by mass or more. As described above, the porous body has water absorption capable of maintaining the water content of the evaporation part at 50% by mass or more, whereby the evaporation amount from the evaporation part can be approximated to the evaporation amount from the leaves of the crop. it can.

  In the evaporation potential measuring apparatus, it is preferable that the specific heat of the porous body is 2000 J / kg / K or more and 5500 J / kg / K or less. Thus, since the temperature of the evaporating part can be brought close to the temperature of the leaves of the crop when the specific heat of the porous body is within the above range, the amount of evaporation from the evaporating part is the amount of evaporation from the leaves of the crop. Can be closer.

  In the evaporation potential measuring device, the thickness of the porous body is preferably 0.01 mm or more and 3 mm or less. Thus, when the thickness of the porous body is within the above range, the evaporation amount from the evaporation section can be made closer to the evaporation amount from the leaves of the crop.

  Here, “having light reflectivity” means that the solar reflectance measured in accordance with JIS-K5602 (2008) is 50% or more.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of an evaporation potential measuring apparatus according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an evaporation potential measuring apparatus according to an embodiment of the present invention. The evaporation potential measuring device connects a water tank 1 for storing water, an immersion part 2 immersed in the water stored in the water tank 1, an evaporation part 3 stretched in the air, an immersion part 2 and an evaporation part 3. A porous body 5 having a connection portion 4, a holding member 6 disposed on the water tank, covering both sides of the connection portion 4 and supporting the end of the evaporation portion 3, and the water level of the water tank 1 being kept constant. A water supply mechanism 7 for supplying water to the water tank 1 and a water amount detection mechanism 8 for detecting the amount of water entering and exiting the water tank 1 are provided.

<Water tank 1>
The water tank 1 has a water tank body 9 that stores water and a lid plate 10 that seals an upper opening of the water tank body 9 so as to cover the upper surface of the water surface. Since the water tank 1 has the cover plate 10, it is possible to prevent water from evaporating in the water tank 1 and dissipate into the atmosphere, thereby suppressing a measurement error of the evaporation potential measuring device.

  As water stored in the water tank 1, pure water is preferably used. By storing pure water in the water tank 1, it is possible to prevent the dissolved components in the water from being concentrated by evaporation of water in the evaporation section 3 of the porous body 5 and changing the evaporation characteristics of the evaporation section 3. Evaporation potential can be measured relatively accurately throughout the growing season of the crop.

The evaporation potential is the amount of water that evaporates per unit time from a leaf in a unit area under the current environmental conditions such as temperature, humidity, wind, and sunshine. The unit is [L / m ² / h]. Can be represented.

  As a capacity | capacitance (water storage amount) of the water tank 1, the water of the quantity which can immerse the immersion part 2 of the porous body 5 should just be stored. Specifically, the lower limit of the capacity of the water tank 1 is preferably 50 mL, and more preferably 100 mL. On the other hand, as an upper limit of the capacity | capacitance of the water tank 1, 1000 mL is preferable and 500 mL is more preferable. When the capacity of the water tank 1 is less than the above lower limit, there is a possibility that water cannot be sufficiently supplied to the porous body. On the contrary, when the capacity of the water tank 1 exceeds the above upper limit, the amount of water directly evaporated from the water tank 1 may increase and the measurement error of the evaporation potential may increase.

  The aquarium 1 (aquarium body 9 and cover plate 10) absorbs light and warms the water in the interior so that the water is not excessively evaporated to cause measurement errors, for example, by coating, surface treatment, painting, etc. It preferably has reflectivity.

  The lower limit of the light reflectance of the water tank 1 is preferably 50% in terms of solar reflectance, and more preferably 70%. If the light reflectance of the water tank 1 is less than the lower limit, the water in the water tank 1 may directly evaporate and dissipate to cause measurement errors.

<Porous body>
The porous body 5 supplies water stored in the water tank 1 from the immersion part 2, supplies water to the evaporation part 3 through the connection part 4 by capillary action, and maintains the evaporation part 3 in a wet state. That is, the immersion part 2, the connection part 4, and the evaporation part 3 reproduce water supply by a plant root, water supply by a stem (stem), and water evaporation in a leaf.

  In the porous body 5, the immersion part 2, the evaporation part 3, and the connection part 4 may be formed from different materials, respectively, or the whole may be formed from a single porous sheet. By forming the whole porous body 5 with a single porous sheet, the porous body 5 can be provided inexpensively and easily, and the porous body 5 is exchanged according to the type of crop to be cultivated. Will also be easier. The porous sheet forming the porous body 5 may be subjected to, for example, embossing, bending (such as wrinkling or pleating).

  The sheet-like porous body 5 may be in the form of a band in which one immersion part 2 and one evaporation part 3 are connected by one connection part 4, but water supply to the evaporation part 3 is easy In order to achieve this, it may be in the form of a long band in which the connection part 4 and the immersion part 2 are continuously provided on both sides of the evaporation part 3, and the opposite ends of the immersion part 2 and the evaporation part 3 are connected to each other. An endless belt shape having a pair of connecting portions 4 may be used.

  The porous body 5 is formed of a porous material having a sufficient water absorption rate so that the moisture content of the evaporation part 3 being measured can be kept sufficiently large. Specifically, the lower limit of the moisture content of the evaporation part 3 during measurement is preferably 50% by mass, and more preferably 80% by mass. On the other hand, the upper limit of the moisture content of the evaporation part 3 during measurement is preferably 97% by mass, and more preferably 95% by mass. When the moisture content of the evaporating unit 3 during measurement is less than the lower limit, the measurement error may increase due to the difference between the evaporating characteristic of the evaporating unit and the evaporation characteristic of the crop leaf. On the contrary, when the moisture content of the evaporation part 3 under measurement exceeds the upper limit, the strength of the evaporation part 3 may be insufficient.

  As a material which comprises the immersion part 2, the evaporation part 3, and the connection part 4 of this porous body 5, a woven fabric, a nonwoven fabric, ceramics etc. can be used, for example. Among the porous bodies 5, it is particularly preferable that the evaporation part 3 is formed from a sheet-like material. Since the evaporation part 3 is a sheet | seat shape with small thickness, the evaporation characteristic similar to the leaf of a crop is acquired, and the precision of the said evaporation potential measuring apparatus can be improved.

  As a minimum of average thickness of evaporation part 3, 0.1 mm is preferred and 0.2 mm is more preferred. On the other hand, as an upper limit of the average thickness of the evaporation part 3, 3 mm is preferable and 1 mm is more preferable. When the average thickness of the evaporation part 3 is less than the said minimum, there exists a possibility that sufficient water cannot be supplied to the part far from the connection part 4 of the evaporation part 3. FIG. On the contrary, when the average thickness of the evaporation part 3 exceeds the said upper limit, there exists a possibility that the difference between the evaporation characteristic from the evaporation part 3 and the evaporation characteristic of the leaf of a crop may become large.

As a minimum of the area of the evaporation part 3, 1 cm < ² > is preferable and 10 cm < ² > is more preferable. On the other hand, as an upper limit of the area of the evaporation part 3, 300 cm < ² > is preferable and 200 cm < ² > is more preferable. If the area of the evaporation unit 3 is less than the lower limit, the evaporation amount from the evaporation unit 3 may be too small to easily measure the evaporation potential. On the contrary, when the area of the evaporation unit 3 exceeds the above upper limit, the evaporation amount from the evaporation unit 3 becomes large, which may make the replenishment of water complicated, or the water tank 1 becomes large and directly from the water tank 1. There is a risk that the error due to evaporation of the water becomes large.

  The lower limit of the specific heat of the evaporation unit 3 is preferably 2000 J / kg / K, and more preferably 3000 J / kg / K. On the other hand, the upper limit of the specific heat of the evaporation section 3 is preferably 5500 J / kg / K, and more preferably 4500 J / kg / K. When the specific heat of the evaporation unit 3 is less than the lower limit, the temperature of the evaporation unit is excessively increased, and there is a possibility that the difference between the evaporation characteristics from the evaporation unit 3 and the evaporation characteristics of the crop leaves becomes large. On the other hand, when the specific heat of the evaporation unit 3 exceeds the above upper limit, the temperature of the evaporation unit becomes difficult to change, and the difference between the evaporation characteristic from the evaporation unit 3 and the evaporation characteristic of the leaves of the crop may increase. .

  The evaporation unit 3 is preferably held parallel to the water surface of the water tank 1, that is, horizontally. Thereby, the average amount of evaporation of the leaves of the crop can be measured with respect to environmental conditions having directivity such as wind and sunshine.

  In order to be able to measure the evaporation potential that accurately reflects the influence of the wind, it is preferable that the evaporation unit 3 is disposed below, for example, with a sufficient space between the lid plate 10. Specifically, the lower limit of the average height of the space below the evaporation unit 3 (the average distance between the evaporation unit 3 and the cover plate 10) is preferably 0.1 cm, and more preferably 1 cm. On the other hand, the upper limit of the average height of the space below the evaporation unit 3 is preferably 50 cm, and more preferably 10 cm. When the average height of the space below the evaporation unit 3 is less than the lower limit, there is a possibility that measurement error may occur due to the fact that air cannot naturally pass between the evaporation unit 3 and the cover plate 10. On the contrary, when the average height of the space below the evaporation unit 3 exceeds the upper limit, when the evaporation potential is large, water supply from the connection unit 4 to the evaporation unit 3 may be insufficient and a measurement error may occur. If the evaporation potential measuring device becomes unnecessarily large, the crop cultivation space may be unnecessarily limited.

  The distance between the immersion unit 2 and the evaporation unit 3 is selected so that water can be supplied to the evaporation unit 3 via the connection unit 4 at a speed higher than the rate at which water evaporates from the evaporation unit 3. Specifically, the evaporation characteristics from the evaporation unit 3 are determined by the surface area, thickness, pore shape and porosity, specific heat, color, surface processing, and the like of the evaporation unit 3. On the other hand, the water supply capacity of the connection part 4 is determined by the strength of the capillary phenomenon determined by the material of the connection part 4, the pore shape, the porosity, etc., the cross-sectional area of the connection part 4, the length, the inclination angle with respect to the horizontal, etc. .

  It is preferable that the evaporation part 3 has a relatively high light absorptance like a general leaf. Specifically, the lower limit of the total light absorption rate of the evaporation unit 3 is preferably 60%, and more preferably 70%. Conversely, the upper limit of the total light absorption rate of the evaporation unit 3 is preferably 95% and more preferably 90%. When the total light absorption rate of the evaporation part 3 is less than the said minimum, there exists a possibility that a measurement error may become large because the evaporation promotion of the evaporation part 3 by solar radiation becomes insufficient compared with the leaf of a crop. On the contrary, when the total light absorption rate of the evaporation part 3 exceeds the said upper limit, there exists a possibility that the other physical property of the evaporation part 3 may become inadequate, and the porous body 5 may become unnecessarily expensive. In addition, it shall mean the value measured based on "total light absorption rate" JIS-K7361-1 (1997).

<Holding member>
The holding member 6 may be formed to have a pair of wall portions that cover at least both surfaces of the connection portion 4 of the porous member 5, and may be formed in a flat cylindrical shape that also covers the side edges of the connection portion 4. The holding member 6 covers the connecting portion 4 of the porous member 5 and prevents water from evaporating from the connecting portion 4.

  The holding member 6 is disposed so as to protrude upward from the lid plate 10 of the water tank 1. The holding member 6 serves as a support for holding both ends of the evaporation part 3 of the porous member 5 and stretching the evaporation part 3 into the air. For this reason, when the holding member 6 protrudes upward from the cover plate 10, the evaporation unit 3 can be separated from the water tank 1 so as to reflect the influence of the wind.

  In order to facilitate attachment / detachment of the porous body 5, the holding member 6 is preferably provided so that a wall portion covering one surface side of the connection portion 4 and a wall portion covering the other surface side can be separated. . As an example, the holding member 6 can be configured such that one wall portion is fixed to the water tank body 9 and the other wall portion is fixed to the lid plate 10.

  The holding member 6 preferably has a minute clearance between the holding portion 6 and the connecting portion 4 so as not to hinder the supply of water to the evaporation portion 3 due to the capillary action of the connecting portion 4 of the porous member 5. Specifically, the lower limit of the difference between the average distance between the pair of wall portions of the holding member 6 and the average thickness of the connection portion 4 is preferably 0.3 mm, and more preferably 0.5 mm. On the other hand, the upper limit of the difference between the average distance between the pair of wall portions of the holding member 6 and the average thickness of the connection portion 4 is preferably 1.5 mm, and more preferably 1.0 mm. If the difference between the average distance between the pair of wall portions of the holding member 6 and the average thickness of the connection portion 4 is less than the lower limit, the amount of water supplied to the evaporation portion 3 via the connection portion 4 may be insufficient. There is. On the other hand, when the difference between the average distance between the pair of wall portions of the holding member 6 and the average thickness of the connection portion 4 exceeds the upper limit, water evaporates from the connection portion 4 so that the measurement accuracy of the evaporation potential measuring device is increased. May decrease.

  The holding member 6 preferably has light reflectivity like the water tank 1 in order to more reliably prevent water from evaporating from the connecting portion 4.

<Water supply mechanism>
For example, the water supply mechanism 7 may be configured to detect the water level of the water tank 1 with a sensor and electronically control a pump or a valve. It can be set as the structure which has the water supply tank 11 and the valve mechanism 12 which opens and closes the flow path which supplies water from the water supply tank 11 to the water tank 1 so that the water level of the water tank 1 may be kept constant.

  The water supply tank 11 is arrange | positioned above the water tank 1, and can be comprised so that water can be supplied to the water tank 1 by gravity. Moreover, you may provide the water supply tank 11 so that attachment or detachment from other components, such as the water tank 1, is possible. By making the water supply tank 11 detachable, it becomes easy to replenish the water supply tank 11 with water when the evaporation potential sensor is fixed near the crop.

  Moreover, the water supply tank 11 may be arrange | positioned separately from the water tank 1, and you may perform the water supply to the water tank 1 via a pipe. By disposing the water supply tank 11 separately, the main body unit excluding the water tank 1 and thus the water supply tank 11 of the evaporation potential sensor can be reduced in size, and the main body unit can be disposed in the vicinity of the crop. The potential can be measured more accurately.

  As the valve mechanism 12, for example, a mechanism for driving a valve by a float floated on the water surface of the water tank 1, an opening of an air flow path in which the sealed water supply tank 11 sucks in air of the same volume as the water replenished by the water tank 1 It is possible to employ a mechanism or the like that stops the outflow of water from the water supply tank 11 by sealing with one water surface.

  By maintaining the water level of the water tank 1 constant by the water supply mechanism 7, the water supply capability from the immersion part 2 to the evaporation part 3 via the connection part 4 becomes constant, and the measurement error of the evaporation potential can be reduced. it can.

<Water volume detection mechanism>
Can be configured to detect the amount of water supplied from the water supply mechanism 7 to the water tank 1. In this way, by making the water level of the water tank 1 constant by the water supply mechanism 7 and detecting the amount of water supplied from the water supply mechanism 7 to the water tank 1 by the water amount detection mechanism 8, the amount of water supplied from the water tank 1 to the evaporation unit 3, That is, the amount of water evaporated from the evaporation unit 3 can be confirmed.

The amount of water supplied from the water supply mechanism 7 to the water tank 1 may be measured using, for example, a flow meter or the like, but it is easy to measure as the amount of water stored in the water supply tank 11. Specifically, the water amount detection mechanism 8 can use, for example, a load cell that detects a change in weight of the water supply tank 11, a sensor that detects a displacement of the liquid level of the water supply tank 11, and the like.

  Among them, as a sensor for detecting the displacement of the liquid level of the water supply tank 11, a pair of linear or ribbon electrodes are attached to the outer wall of the water supply tank 11 in a spiral and parallel to each other, and the capacitance between the electrodes is measured. By using the sensor to detect, a minute change in water level can be detected relatively accurately.

  Moreover, since the weight of the water stored in the water tank 1 is kept constant, the water amount detection mechanism 8 includes other water supply tanks 11, other evaporation potential measuring devices such as the water tank 1, the porous body 5, and the holding member 6. You may comprise so that the change of the total weight with a component may be detected.

  Further, the water amount detection mechanism 8 may be an index such as a scale for visually confirming a decrease in the water amount in the water supply tank 11, and may have a structure that makes it easy to understand a water amount change such as a manometer.

<How to use>
When using the evaporation potential measuring device, the amount of water supplied to the water tank 1 is confirmed by the water amount detection mechanism 8 at regular time intervals, and the amount of water supply per hour, that is, the amount of evaporation per hour is calculated. Calculate the potential.

  However, since wind influences appear locally, the measured value at each time represents the value of the local evaporation potential, not the average evaporation potential for the entire crop, but the average evaporation potential. It can be said that noise due to local influence such as wind is superimposed. For this reason, it is preferable to handle the value obtained by smoothing the measured value of the evaporation potential measuring device at each time as the evaporation potential. As a method for smoothing the measurement value, for example, a method of calculating a moving average such as an exponential smoothing method is preferably used.

<Advantages>
By using the evaporation potential (moving average value) measured using the evaporation potential measurement device, the effects of evaporation potential on the amount of irrigation in hydroponics are corrected, and the degree of growth of crops can be grasped relatively accurately. can do. For this reason, it is possible to improve the quality of the crop and increase the yield by more appropriately controlling the irrigation amount and fertilization amount in the cultivation system using the evaporation potential measuring device.

  The evaporation potential measured using the evaporation potential measuring device is a useful index for evaluating the growth environment of crops. Traditionally, there are many types of experts to evaluate the impact on water evaporation due to the installation of light-blocking buildings such as greenhouses and solar power generation facilities for solar sharing above the crops. Although it was not easy to use an expensive facility equipped with individual sensors and an advanced analysis function, the evaporating potential measuring device can be implemented relatively easily. In this way, by using the evaporative potential measurement device, it becomes possible to quantitatively evaluate changes in the growth environment of natural crops or artificial crops. It is possible to create an optimal land use plan.

  Estimate and map the evaporation potential over a wide area by machine learning or big data analysis that refers to the measured values of the individual sensors, general environmental observation values published by the Japan Meteorological Agency, etc. Is possible. In other words, by utilizing existing sensor equipment, external data, etc., it is possible to grasp a wide range of growth environment only by installing a small number of the evaporation potential sensors.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  The evaporating potential measuring device may use a sufficiently large water tank and omit the water supply mechanism. In this case, the water amount detection mechanism is configured to detect the amount of water stored in the water tank.

In the evaporation potential measuring device, the lid of the water tank may be a float that floats on the water surface. Further, the water tank may not have a cover plate. In addition, evaporation from the water tank may be prevented by covering the water surface with an oil film or the like instead of the cover plate.
It may be.

  In the evaporation potential measuring device, a unit in which the holding member and the connecting portion of the porous body are integrated may be used. As an example, you may use the pseudo stem formed by stuffing cotton etc. which have water absorption as a connection part in a pipe-shaped holding member.

  In the evaporation potential measuring apparatus, instead of the holding member that covers the connection portion of the porous body, a solid member that holds the evaporation portion so as to stretch in the air, and a covering member such as an impermeable sheet that covers the connection portion And may be used.

  In the evaporation potential measuring apparatus, the porous body may not have a connection portion. For example, the porous body may penetrate the side wall of the water tank, and the inside of the water tank may be an immersion part and the outside may be an evaporation part.

  In the evaporating potential measuring apparatus, the evaporating part of the porous body may be stretched in the air in a vertically upright or inclined state. Moreover, the evaporation part of a porous body may have the rigidity which can be supported by cantilever. For this purpose, the evaporation part may have a framework structure or a frame.

  The evaporating potential measuring apparatus may have a plurality of evaporating units.

  The evaporative potential measuring apparatus according to the embodiment of the present invention can be particularly suitably used to correct the influence of the environment when grasping the degree of growth of crops from the amount of water supply.

DESCRIPTION OF SYMBOLS 1 Water tank 2 Immersion part 3 Evaporation part 4 Connection part 5 Porous body 6 Holding member 7 Water supply mechanism 8 Water quantity detection mechanism 9 Water tank main body 10 Cover plate 11 Water supply tank 12 Valve mechanism

Claims (9)

A water tank for storing water;
A porous body having an immersion part immersed in water stored in the water tank and an evaporation part stretched in the air;
An evaporation potential measuring device comprising: a water amount detecting mechanism for detecting the amount of water entering and exiting the water tank. The porous body is in the form of a sheet, and has a connection part that connects the immersion part and the evaporation part,
The evaporation potential measuring device according to claim 1, further comprising a holding member that is disposed on the water tank and covers both surfaces of the connection portion and supports an end portion of the evaporation portion. The water tank has a cover plate that covers the upper surface of the water surface,
The evaporation potential measuring device according to claim 2, wherein the holding member protrudes from the lid plate. The evaporating part is held parallel to the water surface of the water tank,
The evaporation potential measuring device according to claim 3, wherein an average distance between the evaporation section and the lid plate is 0.1 cm or more and 50 cm or less.   The evaporation potential measuring device according to claim 2, 3 or 4, wherein the water tank and the holding member have light reflectivity. A water supply mechanism for supplying water to the water tank so as to keep the water level of the water tank constant;
The evaporation potential measuring device according to any one of claims 1 to 5, wherein the water amount detection mechanism detects a water supply amount from the water supply mechanism to the water tank.   The evaporation potential measuring device according to any one of claims 1 to 6, wherein the porous body has a water absorption property capable of maintaining a moisture content of the evaporation portion at 50% by mass or more.   The evaporation potential measuring device according to any one of claims 1 to 7, wherein the specific heat of the porous body is 2000 J / kg / K or more and 5500 J / kg / K or less.   The evaporation potential measuring device according to any one of claims 1 to 7, wherein a thickness of the porous body is 0.01 mm or more and 3 mm or less.

Images