Supplementary fertilizer device and hydroponic device

Abstract

To provide a topdressing device capable of carrying out proper topdressing hardly affecting the growth of a plant, and to provide a hydroponics apparatus equipped with the topdressing device.SOLUTION: At least two kinds of fertilizers of a first fertilizer containing a first component and at least a second component and a second fertilizer containing the first component and at least a third component are separately held in a topdressing fertilizer holding part 121 as topdressing fertilizers, and a detection part 11 detects each concentration of at least the first component to the third component in a nutrient solution used for hydroponics. When the additional fertilization control part 132 determines that the concentration value of the first component is less than the additional fertilization reference value by the detection, each use amount of at least the first fertilizer and the second fertilizer to be additionally fertilized is determined according to each concentration value of the detected second component and third component, and the additional fertilization is performed by the determined amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a top-dressing device used in a hydroponic cultivation apparatus for cultivating plants, and to a hydroponic cultivation apparatus equipped with the same. [Background technology]

[0002] Various types of hydroponic cultivation devices have been proposed for cultivating plants such as vegetables. Among these, there is a nutrient solution circulation type cultivation device that has a cultivation tank for growing plants and circulates a nutrient solution containing nutrients through this cultivation tank.

[0003] In this type of nutrient solution circulation hydroponics, the nutrient solution concentration is controlled by the EC value, which is related to electrical conductivity, and the nutrient solution pH is controlled by the pH value. When controlling the nutrient solution using the EC value and pH value, specific components in the nutrient solution decrease as they are absorbed by the plants, so top dressing is used to compensate for these specific components. Fertilizers are made up of a mixture of multiple compounds, so they contain multiple components. The same applies to top dressing fertilizers.

[0004] Fertilizers for top dressing contain multiple components, and when top dressing is applied to replenish the components (nutrient components) necessary for the target plants in hydroponic cultivation, other components may also increase in the nutrient solution. If the increased amount of these other components exceeds the target plants' tolerance limit, it may have a negative impact on plant growth. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-143674 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide a top-dressing device that can provide appropriate top-dressing with little adverse effect on plant growth, and a hydroponic cultivation device equipped with the same. [Means for solving the problem]

[0007] The present invention provides a top-dressing device comprising: a detection unit that detects components contained in a nutrient solution used for hydroponics; a top-dressing fertilizer holding unit that holds a top-dressing fertilizer to be added to the nutrient solution; and a top-dressing control unit that controls the addition of the top-dressing fertilizer to the nutrient solution, wherein the top-dressing fertilizer holding unit separately holds at least two types of fertilizer as the top-dressing fertilizer: a first fertilizer containing a first component and at least a second component; and a second fertilizer containing the first component and at least a third component; the detection unit detects the concentrations of at least the first component, the second component, and the third component in the nutrient solution; and, when the top-dressing control unit determines through the detection that the concentration value of the first component is less than a top-dressing standard value, the top-dressing control unit determines the amounts of at least the first fertilizer and the second fertilizer to be used as top-dressing in accordance with the detected concentration values ​​of the second component and the third component, and applies the top-dressing in the determined amounts.

[0008] According to this configuration, it is possible to apply appropriate amounts of the first fertilizer and the second fertilizer in accordance with the detected concentration values ​​of the second component and the third component.

[0009] Furthermore, the top dressing device of the present invention further includes a memory unit, and the memory unit can be configured to store the results of the detection by the detection unit and the amounts of at least the first fertilizer and the second fertilizer used in the addition by the top dressing control unit in chronological order.

[0010] According to this configuration, the stored time-series data can be used for various purposes.

[0011] Furthermore, in the present invention, when the top dressing control unit determines through the detection that the concentration value of a component other than the first component exceeds the discharged liquid standard value, the top dressing control unit can be configured to discharge the nutrient solution from the nutrient solution circulation path to the outside and replace it with new nutrient solution.

[0012] According to this configuration, when the concentration values ​​of components other than the first component become too high, the components of the nutrient solution can be normalized by replacement.

[0013] The present invention also provides a hydroponics device comprising a cultivation tank in which plants are grown using the nutrient solution, a circulation mechanism that circulates the nutrient solution through the cultivation tank, and a top dressing device connected to the cultivation tank or the circulation mechanism to provide top dressing.

[0014] This configuration makes it possible to provide a hydroponic cultivation device that can provide appropriate top dressing. [Effects of the Invention]

[0015] The present invention allows for the application of appropriate amounts of the first fertilizer and the second fertilizer, respectively, and therefore allows for appropriate top dressing that is less likely to adversely affect plant growth. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a block diagram showing the configuration of a top-dressing device according to one embodiment of the present invention. [Figure 2] FIG. 4 is a flow chart showing top dressing control by the top dressing device. [Figure 3] FIG. 3 is a flow chart showing in detail a part of the top dressing control by the top dressing device. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below by taking up one embodiment and by referring to the drawings.

[0018] The basic configuration of the hydroponic cultivation apparatus to which the fertilizing device 1 of this embodiment is to be provided is the same as that of conventional ones, and includes a cultivation tank in which plants are grown with nutrient solution, and a circulation mechanism made up of a pump, piping, etc. that circulates the nutrient solution through the cultivation tank (these are included in the "hydroponic cultivation apparatus (main body) (10)" shown in FIG. 1 and are not shown individually). This hydroponic cultivation apparatus includes the fertilizing device 1 connected to the cultivation tank or the circulation mechanism so as to provide fertilization. The fertilizing device 1 may be built into the hydroponic cultivation apparatus from the beginning, or may be attached as an add-on to an existing hydroponic cultivation apparatus.

[0019] As shown in the block diagram of FIG. 1, the basic configuration of the top dressing device 1 of this embodiment includes a detection unit 11 that detects components contained in the nutrient solution circulating to the cultivation tank in the nutrient solution cultivation device, a top dressing fertilizer supply unit 12 that holds the top dressing fertilizer to be added to the nutrient solution and adds the top dressing fertilizer to the main body 10 of the nutrient solution cultivation device (specifically, the cultivation tank or the circulation mechanism of the main body 10), and a nutrient solution management unit 13 that manages the nutrient solution and controls the addition of the top dressing fertilizer to the circulating nutrient solution as needed.

[0020] The top-dressing fertilizer supply unit 12 includes a top-dressing fertilizer holding unit 121 that holds the top-dressing fertilizer. The top-dressing fertilizer holding unit 121 is, for example, a tank that holds the top-dressing fertilizer, which is liquid fertilizer. At least two types of fertilizer are used as the top-dressing fertilizer: a first fertilizer containing a first component and at least a second component as nutrients, and a second fertilizer containing the first component and at least a third component. The top-dressing fertilizer holding unit 121 holds the multiple fertilizers separately to prevent them from mixing before top-dressing. The top-dressing fertilizer holding unit 121 can also hold other fertilizers, such as a third fertilizer, depending on the fertilizer to be used for top-dressing. FIG. 1 shows an example in which three top-dressing fertilizer holding units 121 are provided.

[0021] The top dressing fertilizer supply unit 12 includes a fertilizer conveying unit 122. The fertilizer conveying unit 122 includes a top dressing piping 1221 that connects the top dressing fertilizer holding unit 121 and the hydroponic cultivation device (main body) 10, and a pump 1222 that circulates the top dressing fertilizer through the top dressing piping.

[0022] The specific contents of the first, second, and third components in the topdressing fertilizer are not particularly limited. However, for ease of understanding, the following are merely illustrative: an example of the first component is nitric acid, which is the most important component for plant growth; an example of the second component is potassium; and an example of the third component is calcium. As fertilizers containing these exemplified components, potassium nitrate is an example of the first fertilizer, and calcium nitrate is an example of the second fertilizer. Incidentally, commonly used compound fertilizers contain all of the first, second, and third components, and in the initial stage before topdressing, an aqueous solution of such compound fertilizers is typically used as the nutrient solution. When these fertilizers are dissolved in water, the first fertilizer becomes an aqueous solution containing nitrate ions and potassium ions, while the second fertilizer becomes an aqueous solution containing nitrate ions and calcium ions. Therefore, when the second fertilizer (more specifically, an aqueous solution of the second fertilizer) is used as the topdressing fertilizer, nitrate ions and calcium ions are added to the nutrient solution. If the first component, nitrate, is in short supply to the target plant in hydroponic culture, top dressing of the first or second fertilizer may result in an excess of potassium or calcium in the solution. The top dressing control unit 132 in this embodiment controls the top dressing of the first or second fertilizer in a pattern that is less likely to disrupt the balance of components in the solution. A specific control flow will be described later.

[0023] The detection unit 11 detects the concentrations of at least a first component, a second component, and a third component (three or more components) in the nutrient solution. Specifically, the detection unit 11 includes a first component concentration sensor 111, a second component concentration sensor 112, and a third component concentration sensor 113, which are ion sensors that detect the ion concentrations corresponding to the three components in the solution. Depending on the design of the top dressing device 1, the detection unit 11 may also be able to detect the concentration of a component other than the three components, such as a fourth component. However, because detecting three components as in this embodiment allows for appropriate top dressing to be applied to the majority of plants (e.g., vegetables), detecting three components is preferable from a cost perspective.

[0024] The nutrient solution management unit 13 includes a measurement value acquisition unit 131 that receives the detection signal from the detection unit 11, and a top-fertilization control unit 132. When the top-fertilization control unit 132 determines that the concentration of the first component detected by the detection unit 11 is below the top-fertilization reference value, the top-fertilization control unit 132 determines the amounts of at least the first and second fertilizers to be top-fertilized based on the detected concentrations of the second and third components, and top-fertilizes the determined amounts. For example, assuming that the component to be top-fertilized is the first component (e.g., nitrate), if the concentration of the second component (e.g., potassium) is high at the time of detection, the top-fertilization control unit 132 controls the top-fertilization to be performed with a high proportion of the second fertilizer containing the third component (e.g., calcium). Conversely, if the concentration of the third component is high at the time of detection, the top-fertilization control unit 132 controls the top-fertilization to be performed with a high proportion of the first fertilizer containing the second component. By top-fertilizing in this manner, it is possible to prevent excessive accumulation of components unnecessary for the target plants in hydroponic cultivation in the nutrient solution, as in the conventional method, and to top-fertilize the first and second fertilizers in appropriate amounts based on the detected concentrations of the second and third components. The top-dressing control unit 132 is configured by a personal computer or a microcomputer provided in the top-dressing device 1. The top-dressing control unit 132 is configured by a personal computer or a microcomputer provided in the top-dressing device 1.

[0025] The top-fertilization device 1 of this embodiment further includes a memory unit 133. This memory unit 133 may share a partial area of ​​a memory device included in the top-fertilization control unit 132, for example. This memory unit 133 stores the results of detection by the detection unit 11 and the amounts of at least the first fertilizer and the second fertilizer added by the top-fertilization control unit 132 in chronological order. The memory unit 133 is advantageous because the stored chronological data can be used later for various purposes such as analysis and management.

[0026] The control details of the top-dressing control unit 132 will now be described with reference to the flowcharts of FIGS. 2 and 3. In FIGS. 2 and 3, the first component is denoted as "component X," the second component as "component Y," and the third component as "component Z." The measurement value acquisition unit 131 acquires the measurement values ​​(concentration values) of the detection unit 11 at predetermined time intervals (steps S1 and S2). The "predetermined time interval" can be set as appropriate, for example, one day (24 hours). The acquired measurement values ​​are input into a top-dressing determination / top-dressing amount calculation sheet, which is pre-set in the data, in the top-dressing control unit 132 (step S3). The sheet may be in various formats, such as a spreadsheet. A calculation formula is incorporated into the sheet so that, when the concentration values ​​of each component are input, the necessity of top-dressing and, if top-dressing is necessary, the top-dressing rate and amount of each fertilizer are output. This calculation formula is created corresponding to the proportions of the first to third components contained in each fertilizer used as top-dressing fertilizer. On the sheet, whether the balance between the second component (component Y) and the third component (component Z) in the nutrient solution is normal is judged into three patterns: normal, excess, and deficiency (step S4).

[0027] If the component balance is determined to be "normal," a determination is made as to whether or not additional fertilization is necessary (Step S5). This is because additional fertilization may be performed preventatively even if the components are within the normal range. If additional fertilization is determined to be necessary, additional fertilization is performed (Step S6). More specifically, as shown in FIG. 3, it is determined whether the first component (component X) is within a preset range A (Step S61), and if it is within range A, additional fertilization is performed by adding a second component (component Y) and a third component (component Z) at a preset ratio (volume ratio, the same applies below) a (Step S62).

[0028] If the amount does not fall within range A, it is determined whether the second component (component Y) is within a preset range B (step S63), and if it is outside range B, the second component (component Y) and the third component (component Z) are top dressed at a preset ratio b (step S64). In this embodiment, the ratio b is set to the same ratio as the ratio a (but is not limited to this).

[0029] If it is within range B, it is further determined whether the third component (component Z) is within a preset range C (step S65). If it is within range C, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio c (step S66). If it is outside range C, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio d (step S67). In this embodiment, the ratios are set so that the amount of the second component (component Y) relative to the third component (component Z) is highest when the ratio is d, lowest when the ratio is c, and intermediate when the ratio is b (although this is not limited to this).

[0030] Furthermore, if the component balance is determined to be "insufficient," it is determined whether or not additional fertilization is necessary, as shown in FIG. 2 (Step S7). If it is determined that additional fertilization is necessary, additional fertilization is performed (Step S8). More specifically, as shown in FIG. 3, it is determined whether the second component (component Y) and the third component (component Z) are both below a preset lower limit (Step S81), and if this is the case, the second component (component Y) and the third component (component Z) are additionally fertilized at a preset ratio e (Step S82). In this embodiment, the ratio e is set to the same ratio as the ratio a (but is not limited to this).

[0031] If this is not the case, it is determined whether the second component (component Y) is less than a preset lower limit (step S83), and if this is the case, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio f (step S84). In this embodiment, the ratio f is set so that the content is only the second component (component Y) and does not include the third component (component Z) (but is not limited to this). If the condition of step S83 is not met, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio g (step S85). In this embodiment, the ratio g is set so that the content is only the third component (component Z) and does not include the second component (component Y) (but is not limited to this).

[0032] If the component balance is determined to be "excessive," a decision is made as to whether to apply additional fertilization or replace the nutrient solution (Step S9), as shown in Figure 2. Note that Figure 2 indicates whether additional fertilization is necessary. Based on this decision, additional fertilization is applied (Step S10) or the nutrient solution is replaced (Step S11).

[0033] If the component balance is determined to be "excessive," more specifically, as shown in FIG. 3, it is determined whether the second component (component Y) is equal to or greater than a preset upper limit (step S91), and if so, the nutrient solution is replaced, that is, the current nutrient solution is discharged from the circulation path and new nutrient solution is introduced into the circulation path (step S11).

[0034] If this is not the case, it is further determined whether the third component (component Z) is within a preset range D (step S101). If it is within range D, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio h (step S102). In this embodiment, the ratio h is set to the same ratio as the ratio a (but is not limited to this). If it is outside range D, the second component (component Y) and the third component (component Z) are top-dressed at a preset ratio i (step S103). In this embodiment, the ratio i is set to include only the second component (component Y) and not include the third component (component Z) (but is not limited to this).

[0035] In other words, when the top dressing control unit 132 determines through detection that the concentration values ​​of components other than the first component exceed a drainage standard value (for example, the upper limit value of component Y in step S91), the nutrient solution is discharged to the outside from the nutrient solution circulation path and replaced with new nutrient solution. By controlling in this way, if the concentration values ​​of components other than the first component become too high, it becomes difficult to normalize the nutrient solution components using the top dressing procedure, so the nutrient solution components can be normalized by replacing the nutrient solution as a separate procedure.

[0036] Next, if it is determined in step S5 that additional fertilization is not necessary, and after additional fertilization has been performed in each step, as shown in Fig. 2, it is determined whether to continue the control of the additional fertilization control unit 132 (step S12), and if it is to be continued, the process returns to step S1. If it is not to be continued, the control is terminated.

[0037] The fertilizing device 1 of this embodiment is configured as described above. With this fertilizing device 1, it is possible to provide a hydroponic cultivation device that can provide appropriate fertilization.

[0038] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0039] For example, the fertilizer in the above embodiment was a liquid fertilizer that was liquid both at the time of retention and at the time of top dressing. However, this is not limited to this, and a solid fertilizer such as a granular fertilizer may be used at least at the time of retention. In this case, the fertilizer may be added directly to the nutrient solution as top dressing, or the fertilizer may be dissolved in water to form an aqueous solution and then top dressed immediately before top dressing.

[0040] In the above embodiment, nitrate, potassium, and calcium are given as examples of the first to third components, but the present invention is not limited to these, and various components such as ammonia, phosphorus, and magnesium can be measured and used as top dressing.

[0041] Furthermore, the "top-dressing determination and top-dressing amount calculation sheet" used in the above embodiment is merely an example, and it is not essential that it be in the form of a sheet. Therefore, the determination of whether top-dressing is necessary and the calculation of the amount of top-dressing if top-dressing is applied can be performed using various programs.

[0042] In addition, the top dressing device 1 or the hydroponic cultivation device (main body) 10 may be provided with a notification means, and configured to notify an error message or the like if a judgment cannot be made in the flow described in the above embodiment.

[0043] Furthermore, the top-dressing control unit 132 of the top-dressing device 1 may be configured to provide only one unit for a plurality of nutriculture devices, so as to centrally control the top-dressing of the plurality of nutriculture devices.

[0044] In addition to the fertilizing device 1 of the above embodiment, various devices such as a heating / cooling device, a pH adjusting (acidity / alkalinity adjusting) device, a sterilizing device, etc. can be connected to or incorporated into the hydroponic cultivation device. [Explanation of symbols]

[0045] 1 Top dressing device 10. Hydroponic cultivation device (main body) 11. Detection unit 111 First component concentration sensor 112 Second component concentration sensor 113 Third component concentration sensor 12 Fertilizer supply section for top dressing 121 Fertilizer holding part for topdressing 122 Fertilizer conveying section 1221 Top dressing piping 1222 Pump 13 Nutrient Solution Management Department 131 Measurement value acquisition unit 132 Top dressing control unit 133 Storage section

Claims

1. a detection unit that detects components contained in the nutrient solution used in hydroponics; A top dressing fertilizer holding unit that holds a top dressing fertilizer to be added to the nutrient solution; a top dressing control unit that controls the addition of the top dressing fertilizer to the nutrient solution, The top dressing fertilizer holding section contains the following fertilizer: a first fertilizer containing a first component and at least a second component; a second fertilizer containing the first component and at least a third component; At least two types of fertilizers are separately maintained, The detection unit detects the concentrations of at least the first component to the third component in the nutrient solution, When the top dressing control unit determines that the concentration value of the first component is less than the top dressing standard value through the detection, it determines the amount of at least the first fertilizer and the second fertilizer to be used based on the detected concentration values ​​of the second component and the third component, and applies the top dressing in the determined amount.

2. Further comprising a storage unit, The top dressing device according to claim 1, wherein the memory unit stores the results of the detection by the detection unit and the amounts of at least the first fertilizer and the second fertilizer used in the addition by the top dressing control unit in chronological order.

3. The top dressing device according to claim 1, wherein when the top dressing control unit determines through the detection that the concentration value of a component other than the first component exceeds a discharged liquid standard value, the top dressing control unit discharges the nutrient solution from the nutrient solution circulation path to the outside and replaces it with new nutrient solution.

4. a cultivation tank in which plants are grown using the nutrient solution; A circulation mechanism that circulates the nutrient solution through the cultivation tank; A hydroponic cultivation apparatus comprising the fertilizer device according to any one of claims 1 to 3, which is connected to the cultivation tank or the circulation mechanism so as to apply fertilizer.

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