JP2012210168A - Hydroponic cultivation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intermittently supply a culture solution into a cultivation tank and adjust a water level at the proper timing by means of a simple arrangement in a hydroponic cultivation apparatus.SOLUTION: The hydroponic cultivation apparatus 10 includes first and second drain pipes 41, 42 as drain pipes for draining a culture solution in a cultivation tank 11. A high water level, which is the level of draining by the first drain pipe 41, is set to be higher than a low water level, which is the level of draining by the second drain pipe 42, and the flow drained by the first drain pipe 41 is set to be larger than the flow drained by the second drain pipe 42. The flow drained by the first drain pipe 41 and the flow drained by the second drain pipe 42 are set to be respectively larger and smaller than the flow supplied by a water supply pipe 32 when a pump 31 is on for operation. A timer 33 is used to control the on/off of operation of the pump 31.

Description

  The present invention relates to a hydroponic cultivation apparatus for plants such as root vegetables such as garlic or leaf vegetables such as lettuce, mizuna and spring chrysanthemum.

  Conventionally, as a hydroponic cultivation apparatus for garlic sprout (garlic shoots), as described in Patent Document 1, a cultivation bed that supports a plant is arranged above the cultivation tank, and the cultivation nutrient solution pumped by the pump is used as the cultivation tank. There is a thing provided with the drainage pipe which discharges the cultivation nutrient solution inside the cultivation tank while being provided with the water supply pipe which supplies inside.

  In this hydroponic cultivation apparatus for garlic plows, a cultivation basket having a mesh shape, which becomes a cultivation bed, is placed on the upper part of the cultivation tank, the garlic bulbs are placed on the cultivation basket, and the roots of the garlic bulbs on the cultivation basket The cultivation nutrient solution inside the cultivation tank is intermittently supplied and the water level is adjusted so that the cultivation nutrient solution is alternately positioned in the cultivation nutrient solution in the cultivation tank or in the air above the cultivation cultivation solution.

  By positioning the roots of garlic bulbs in the air above the cultivation nutrient solution, root decay of garlic bulbs can be prevented, and moderate stress due to water shortage can be applied. Then, by positioning the roots of garlic bulbs in the water of the cultivation nutrient solution, the cultivation nutrient solution can be absorbed at once by the roots of the garlic bulbs that have been lacking in the air, and the growth of roots, young shoots, and leaves can be promoted. As a result, the taste, flavor, shelf life, etc. of the garlic plow are improved, and the productivity of hydroponics is improved.

Patent 4252101

  In the hydroponic cultivation apparatus described in Patent Literature 1, as a means for intermittently supplying the cultivation nutrient solution inside the cultivation tank and adjusting the water level, a water level sensor provided in the cultivation tank and a control that operates based on the detection result of the water level sensor. Circuit. The control circuit controls the water supply flow rate of the cultivation nutrient solution pumped by the pump via the water supply tube and the discharge flow rate of the cultivation nutrient solution from the cultivation tank adjusted by the electromagnetic valve provided in the drainage pipe. Therefore, their configuration is complicated and inevitably expensive.

  The object of the present invention is to position the roots alternately in the cultivation nutrient solution water and in the cultivation nutrient solution in the air according to the growth of the plant supported on the cultivation bed at the top of the cultivation tank by a simple configuration. Furthermore, it is an object to intermittently supply and adjust the water level of the cultivation nutrient solution inside the cultivation tank at a timely timing.

  The invention which concerns on Claim 1 arrange | positions the cultivation bed which supported the plant in the upper part of a cultivation tank, and while providing the water supply pipe which supplies the cultivation nutrient solution which a pump pumps to the inside of a cultivation tank, inside a cultivation tank In the hydroponic cultivation apparatus provided with the drainage pipe for discharging the cultivation nutrient solution, the drainage pipe for draining the cultivation nutrient solution inside the cultivation tank includes the first and second drainage pipes, and the first drainage pipe is used. The high water level that is the drainage level is higher than the low water level that is the drainage level by the second drain pipe, the drain flow rate of the first drain pipe is set larger than the drain flow rate of the second drain pipe, and the pump is operated Set the drainage flow rate of the first drainage pipe to be larger than the feedwater flow rate of the feedwater pipe when it is turned on, and set the drainage flow rate of the second drainage pipe to be small, and the pump operation is controlled on / off by a timer. To turn on the pump. The water level inside the cultivation tank is set to a high water level by continuing the high water level formation time determined by-, and the roots of the plants supported on the cultivation bed are put into the water of the cultivation nutrient solution set to the high water level. The water level inside the cultivation tank is set to a low water level by allowing the pump to be turned off and continuing to turn off the pump for the low water level formation time set by the timer, and the root of the plant supported on the cultivation bed is lowered to the low level. The cultivation nutrient solution inside the cultivation tank is intermittently supplied and the water level is adjusted so that it can be positioned in the air above the cultivation nutrient solution set at the water level.

  The invention according to claim 2 is the invention according to claim 1, wherein the high water level formation time is a flow rate of the pump water supply flow rate and the drainage flow rate of the second drain pipe when the pump operation is switched from OFF to ON. High water level arrival time for the water level inside the cultivation tank to reach the high water level from the low water level, which is the value obtained by dividing the amount of water stored between the high water level and the low water level inside the cultivation tank due to the difference In addition, a desired high water level duration time for keeping the water level in the subsequent cultivation tank at a high water level is added and calculated.

  According to a third aspect of the present invention, in the first aspect of the present invention, the low water level formation time is determined based on the amount of drainage in the second drain pipe when the pump operation is switched from on to off. The amount of water stored between the high water level and the low water level is divided by the time it takes for the water level inside the cultivation tank to reach the low water level from the high water level. It is calculated by adding a desired low water level duration time to keep the internal water level at a low water level.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the cultivation bed further comprises a cultivation basket having a mesh shape.

  The invention according to claim 5 is the invention according to any one of claims 1 to 3, wherein the cultivation bed further has a cultivation block made of a porous annular body that can be expanded and contracted.

(Claim 1)
(a) By controlling on / off of the pump operation with a timer, the water level inside the cultivation tank is set to a high water level by continuing the pump operation on for the high water level formation time determined by the timer, and cultivation The root of the plant supported on the bed can be located in the water of the cultivation nutrient solution set at its high water level, and the operation of the pump is continued by the low water level formation time determined by the timer. Cultivation inside the cultivation tank so that the internal water level is set to a low water level and the roots of the plants supported on the cultivation bed can be located in the air above the cultivation nutrient solution set at that low water level Supply nutrient solution intermittently and adjust water level.

  Therefore, by positioning plant roots in the air above the cultivation nutrient solution, root rot can be prevented or moderate stress due to water shortage can be applied. Then, by positioning the root of the plant in the water of the cultivation nutrient solution, the cultivation nutrient solution can be absorbed at a stretch by the root of the plant that is short of water in the air, and the growth of roots, young shoots, and leaves can be promoted. Thereby, the taste, flavor, shelf life, etc. of a plant can be made favorable and the productivity of hydroponics can be improved.

  At this time, depending on the plant to be cultivated this time and the season, the optimum time for keeping the root of the plant in the water of the cultivation nutrient solution and the optimum time for keeping it in the air above the cultivation nutrient solution correspond to them. The high water level formation time t1 and the low water level formation time t2 to be set can be easily changed in the timer.

  That is, with a simple configuration including first and second drain pipes and a timer for controlling on / off of the pump operation, the roots are cultivated in the cultivation nutrient solution water in accordance with the growth of the plant. The cultivation nutrient solution inside the cultivation tank can be intermittently supplied and the water level can be adjusted at an appropriate timing so as to be alternately positioned in the air above the nutrient solution.

(Claim 2)
(b) The high water level formation time t1 set by the timer in the above (a), the high water level arrival time t1a determined by the equipment conditions of the cultivation tank, and the desired high water level duration determined according to the plant and season cultivated this time By the time t1b, it is possible to calculate easily and with high accuracy, and to intermittently supply and adjust the water level of the cultivation nutrient solution inside the cultivation tank with high accuracy.

(Claim 3)
(c) The low water level formation time t2 set by the timer in (a) above, the low water level arrival time t2a determined by the equipment conditions of the cultivation tank, and the desired low water level duration determined according to the plant and season cultivated this time By time t2b, it is possible to calculate easily and with high accuracy, and intermittently supply and adjust the water level of the cultivation nutrient solution inside the cultivation tank with high accuracy.

(Claim 4)
(d) Root vegetables such as garlic plows can be cultivated easily and stably by using a cultivation bed made of a cultivation basket having a mesh shape.

(Claim 5)
(e) Leaf vegetables such as lettuce can be cultivated easily and stably by using a cultivation bed having a cultivation block made of a porous annular body that can be expanded and contracted.

FIG. 1 is a schematic side sectional view showing a hydroponic cultivation apparatus. FIG. 2 is a plan view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a schematic perspective view showing a cultivation basket. FIG. 5 is a schematic diagram showing an example of cultivation of garlic plows. FIG. 6: shows a cultivation bed, (A) is a schematic perspective view which shows a cultivation stand, (B) is a schematic perspective view which shows a cultivation block, (C) is a schematic cross section which shows the modification of a cultivation stand. FIG. 7 is a schematic diagram showing an example of lettuce cultivation.

  A hydroponic cultivation apparatus 10 shown in FIGS. 1 and 2 has a cultivation tank 11 installed on a floor surface. The cultivation tank 11 has a rectangular box shape made of, for example, hard plastic, and includes a plurality of rising portions 11 </ b> A to 11 </ b> D raised from the tank bottom surrounded by the outer peripheral wall of the cultivation tank 11 to the inside of the tank. The rising portions 11A and 11B on both sides are extended over the entire length sandwiched between the inner wall surfaces opposed in the longitudinal direction of the cultivation tank 11, and the central rising portions 11C and 11D are formed on the inner wall surfaces opposed in the longitudinal direction of the cultivation tank 11. It extends over a certain range separated from each other. The upper surfaces of the rising portions 11 </ b> A to 11 </ b> D are set at positions slightly lower than the upper surface of the outer peripheral wall of the cultivation tank 11.

  The hydroponics apparatus 10 arrange | positions the cultivation bed 20 which supported the plant on the upper part of the rising parts 11A-11D of the cultivation tank 11. FIG. The cultivation bed 20 will be described later.

  The hydroponic cultivation apparatus 10 has a tank 30 installed on the floor surface below the cultivation tank 11. The tank 30 contains the cultivation nutrient solution L which is the nutrient solution water etc. which mixed water or the fertilizer useful for a plant, microorganisms, etc. with water. The tank 30 is provided with a pump 31 that pumps the cultivation nutrient solution L.

  The hydroponic cultivation apparatus 10 includes a water supply pipe 32 that supplies the cultivation nutrient solution L pumped by the pump 31 to the inside of the cultivation tank 11. The outlet of the water supply pipe 32 opens toward a space between the inner wall surface on one end side in the longitudinal direction inside the tank of the cultivation tank 11 and each one end of the rising portions 11C and 11D.

  The hydroponic cultivation apparatus 10 includes first and second drain pipes 41 and 42 made of, for example, a hard plastic pipe, as drain pipes for discharging the cultivation nutrient solution L inside the cultivation tank 11. The drainage pipes 41 and 42 penetrate the tank bottom of the cultivation tank 11 in a space between the inner wall surface on the other end side in the longitudinal direction inside the cultivation tank 11 and the other end parts of the rising parts 11C and 11D. Are arranged. The inlets at the upper ends of the drainage pipes 41 and 42 stand up from the bottom of the cultivation tank 11 to the levels H1 and H2 inside the tank, and the outlets at the lower ends of the drainage pipes 41 and 42 are tanks below the cultivation tank 11. It opens toward 30.

  The hydroponic cultivation apparatus 10 can be provided with a structure that can freely adjust the standing heights (levels H1, H2) of the drain pipes 41, 42 with respect to the bottom of the cultivation tank 11, and the levels H1, H2 thereof. Can be adjusted easily.

  Moreover, in the hydroponic cultivation apparatus 10, the discharge amount of the pump 31 is changed according to the size of the plant to be cultivated this time (degree of water supply), the length of the root, or the like, or the drain pipe 41, 42 may be exchanged for one having a different diameter and length.

  Accordingly, the hydroponics apparatus 10 is configured so that the roots of the plants supported on the cultivation bed 20 at the top of the cultivation tank 11 are alternately positioned in the cultivation nutrient solution L or in the air above the cultivation nutrient solution L. In order to intermittently supply the cultivation nutrient solution L and adjust the water level, the following configuration is provided.

  (A) The high water level H1 which is the drainage level by the first drain pipe 41 is higher than the low water level H2 which is the drainage level by the second drain pipe 42 (H1> H2). ) Set.

  (B) The drainage flow rate Q1 determined by the diameter of the first drainage pipe 41 is set larger than the drainage flow rate Q2 determined by the diameter of the second drainage pipe 42 (Q1> Q2).

  (C) The drainage flow rate Q1 of the first drainage pipe 41 is larger (Qp <Q1) than the feedwater flow rate Qp from the feed pipe 32 to the cultivation tank 11 when the pump 31 is on, and the second drainage The drainage flow rate Q2 of the pipe 42 is set small (Qp> Q2).

  (D) By performing on / off control of the operation of the pump 31 by the timer 33, the cultivation nutrient solution L inside the cultivation tank 11 is intermittently supplied and the water level is adjusted so as to be as shown in i) and ii) below.

  i) From the state where the water level in the cultivation tank 11 is at the low water level H2 according to the following ii) (the operation of the pump 31 is off), the operation of the pump 31 is turned on. By continuing for t1, the water level inside the cultivation tank 11 is set to the high water level H1 (reaching the high water level and keeping it at that high water level), and the roots of the plant supported on the cultivation bed 20 Can be positioned in the water of the cultivation nutrient solution L set at the high water level H1. The roots of the plants are located in the water of the cultivation nutrient solution L for the high water level formation time t1 (particularly, the high water level duration t1b described later).

  ii) From the state in which the water level in the cultivation tank 11 is at the high water level H1 by i) (the operation of the pump 31 is on), the operation of the pump 31 is turned off, and the low water level formation time determined by the timer 33 is turned off. By continuing only t2, the water level inside the cultivation tank 11 is set to the low water level H2 (to reach the low water level, and to keep at the low water level), and the root of the plant supported on the cultivation bed 20 Can be positioned in the air above the cultivation nutrient solution L set at the low water level H2. Plant roots are located in the air above the cultivation nutrient solution L for a low water level formation time t2 (particularly, a low water level duration t2b described later).

  Here, the high water level formation time t1 of i) is calculated by adding the desired high water level duration t1b to the high water level arrival time t1a when the operation of the pump 31 is switched from OFF to ON. The high water level arrival time t1a is a value determined by the equipment conditions of the hydroponic cultivation device 10, and the flow rate difference ΔQ between the feed water flow rate Qp of the pump 31 and the drainage flow rate Q2 of the second drainage pipe 42 is the inside of the cultivation tank 11. It is a value obtained by dividing the stored water amount A between the high water level H1 and the low water level H2, and is the time for the water level inside the cultivation tank 11 to reach the high water level H1 from the low water level H2. The high water level duration t1b is a value that is determined according to the plant cultivated this time and the season, and is a time during which the water level inside the cultivation tank 11 is kept at the high water level H1.

  The low water level formation time t2 of ii) is calculated by adding the desired low water level duration t2b to the low water level arrival time t2a when the operation of the pump 31 is switched from on to off. The low water level arrival time t2a is a value determined by the equipment conditions of the hydroponic cultivation apparatus 10, and the high water level H1 and the low water level H2 inside the cultivation tank 11 are determined by the drainage flow rate Q2 of the second drain pipe 42. It is the value which remove | divided the water storage amount A in the meantime, Comprising: It is time when the water level inside the cultivation tank 11 reaches | attains the low water level H2 from the high water level H1. The low water level duration t2b is a value determined according to the plant or season cultivated this time, and is a time for keeping the water level inside the cultivation tank 11 at the low water level H2.

According to the hydroponic cultivation apparatus 10, there exist the following effects.
(a) By controlling on / off of the operation of the pump 31 by the timer 33, the operation of the pump 31 is continuously turned on for the high water level formation time t1 determined by the timer 33, whereby the water level in the cultivation tank 11 is set to the high water level. The level of H1 is set and the root of the plant supported on the cultivation bed 20 can be positioned in the water of the cultivation nutrient solution L set at the high water level H1, and the operation of the pump 31 is determined by the timer 33. By continuing the low water level formation time t2, the water level in the cultivation tank 11 is set to the low water level H2, and the root of the plant supported on the cultivation bed 20 is set to the low water level H2. The cultivation nutrient solution L inside the cultivation tank 11 is intermittently supplied and the water level is adjusted so that it can be positioned in the air above the top of the plant.

  Therefore, by positioning the root of the plant in the air above the cultivation nutrient solution L, root rot can be prevented or moderate stress due to lack of water can be applied. Then, by positioning the root of the plant in the water of the cultivation nutrient solution L, the cultivation nutrient solution L can be absorbed at a stretch by the root of the plant that is short of water in the air, and the growth of roots, young shoots, and leaves can be promoted. Thereby, the taste, flavor, shelf life, etc. of a plant can be made favorable and the productivity of hydroponics can be improved.

  At this time, depending on the plant cultivated this time and the season, the optimum time for keeping the root of the plant in the water of the cultivation nutrient solution L and the optimum time for keeping it in the air above the cultivation nutrient solution L are The high water level formation time t 1 and the low water level formation time t 2 corresponding to can be easily changed in the timer 33.

  That is, with a simple configuration including the first and second drain pipes 41 and 42 and the timer 33 for controlling the operation of the pump 31 on / off, the roots are cultivated according to the growth of the plant. The cultivation nutrient solution L inside the cultivation tank 11 can be intermittently supplied and the water level adjusted at an appropriate timing so as to be alternately positioned in the L water and in the air above the cultivation nutrient solution L.

  (b) The high water level formation time t1 set by the timer 33 in the above (a), the high water level arrival time t1a determined by the equipment conditions of the cultivation tank 11, and the desired high determined according to the plant and season cultivated this time The water level duration t1b can be calculated simply and with high accuracy, and the cultivation nutrient solution L inside the cultivation tank 11 can be intermittently supplied and the water level can be adjusted with high accuracy.

  (c) The low water level formation time t2 set by the timer 33 in the above (a), the low water level arrival time t2a determined by the equipment conditions of the cultivation tank 11, and the desired low level determined according to the plant and season cultivated this time The water level duration t2b can be calculated simply and with high accuracy, and the cultivation nutrient solution L inside the cultivation tank 11 can be intermittently supplied and the water level can be adjusted with high accuracy.

Therefore, the following (1) and (2) can be adopted as a hydroponic cultivation method using the hydroponic cultivation apparatus 10.
(1) At the initial stage of plant cultivation, cultivation is performed so that a part of the plant root supported on the cultivation bed 20 is located in the water of the cultivation nutrient solution L set at the high water level H1 inside the cultivation tank 11. The water level of the nutrient solution L is adjusted. Thereby, growth of the root of a plant can be promoted.

  (2) Along with the growth of the plant, the root of the plant supported on the cultivation bed 20 is located in the water of the cultivation nutrient solution L set at the high water level H1 inside the cultivation tank 11, and the cultivation cultivation The cultivation nutrient solution L is intermittently supplied and the water level is adjusted so that the air condition located in the air above the cultivation nutrient solution L set at the low water level H2 inside the solution L is alternately and repeatedly applied. This can promote the growth of plant roots, young shoots, and leaves.

Hereinafter, a specific example in which the hydroponic cultivation apparatus 10 is used for cultivation of garlic plows (root vegetables) and lettuce (leaf vegetables) will be described.
Example 1
Using the hydroponic cultivation apparatus 10, garlic plows were cultivated by the following (1) to (6).

  In the hydroponic cultivation apparatus 10, the first drain pipe 41 was a straight pipe having a diameter of 50 mm, and the second drain pipe 42 was a straight pipe having a diameter of 25 mm.

  Moreover, the cultivation basket 21 shown in FIG. 4 was used as the cultivation bed 20. The cultivation basket 21 has a rectangular flat plate tray shape made of, for example, hard plastic, has a plurality of sections 21A divided vertically and horizontally, and is provided with a plurality of holes 21B provided in each section 21A. Make. The cultivation basket 21 can be used by placing one garlic bulb on one compartment 21A.

  (1) In the timer 33, the high water level formation time t1 is set to 4 hours, and the low water level formation time t2 is set to 2 hours.

  Of the high water level formation time t1, the high water level arrival time t1a is approximately 12 minutes, and the remainder is the high water level duration t1b. Of the low water level formation time t2, the low water level arrival time t2a is approximately 18 minutes, and the remainder is the low water level duration t2b.

  (2) The bulb 1A of garlic 1 was placed on the cultivation basket 21, and this cultivation basket 21 was arranged on the upper part of the rising parts 11A to 11D of the cultivation tank 11 as shown in FIG. 5).

  (3) The timer 33 continues to turn on the operation of the pump 31 for 4 hours of the high water level formation time t1 of the above (1). The pump 31 continues to supply the cultivation nutrient solution in the tank 30 from the water supply pipe 32 to the cultivation tank 11 at a water supply flow rate Qp. During this period, the cultivation nutrient solution supplied by the pump 31 to the cultivation tank 11 causes the water level inside the cultivation tank 11 to reach the low water level H2 of the second drainage pipe 42, and a part thereof is discharged from the second drainage pipe 42. However, the water level is made to reach the high water level H1 of the first drain pipe 41, and thereafter it is discharged by overflow from the first drain pipe 41 for a predetermined high water level duration t1b. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 is set to the high water level H1.

  At this time, the cultivation basket 21 arranged in the upper part of the cultivation tank 11 in the above (2) is set so as to be submerged on the water surface at the high water level H1 or just below the water surface as shown in FIG. 5 (A). The Accordingly, the bottom of the bulb 1A of the garlic 1 on the cultivation basket 21 is located in the cultivation nutrient solution L at the high water level H1 inside the cultivation tank 11, absorbs the cultivation nutrient solution L, and the bulb 1A. From the bottom of the root, the root 1B extends into the water and begins to grow.

  (4) The timer 33 turns off the operation of the pump 31 after 4 hours of the high water level formation time t1 in (3) above, and turns off the operation of the pump 31 in the low water level formation time in (1) above. Continue for 2 hours at t2. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 reaches from the high water level H1 of the first drain pipe 41 to the low water level H2 of the second drain pipe 42, and then the desired low water level. The low water level H2 is maintained for the duration t2b.

  At this time, the root 1B grown from the garlic bulb 1A on the cultivation basket 21 and extending into the water is located in the air above the cultivation nutrient solution L at the low water level H2 inside the cultivation tank 11. As a result, root rot is prevented and moderate stress due to water shortage is given.

  (5) The timer 33 turns off the operation of the pump 31 after the low water level formation time t2 of (4) above has elapsed, and turns on the operation of the pump 31. Continue for 4 hours at t1. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 is changed from the low water level H2 of the second drain pipe 42 to the high water level H1 of the first drain pipe 41 in the same manner as the above (3). And then maintain that high water level H1 for the desired high water level duration t1b.

  At this time, the root 1B of the bulb 1A of the garlic 1 on the cultivation basket 21 is located again in the water of the high water level H1 inside the cultivation tank 11, and the stress due to being in the air in the above (4) The cultivation nutrient solution L is absorbed at a stretch so as to eliminate the problem. Thereby, the growth of the young shoot 1C is rapidly promoted in the garlic 1, and separation of the bulb 1D constituting the bulb 1A is recognized.

  (6) After that, intermittent supply and water level adjustment of the cultivation nutrient solution L in (4) and (5) above are repeated, and the air condition in (4) and the water condition in (5) above are applied to the root 1B of garlic. By repeatedly applying alternately, as shown in FIG. 5 (B), the sprout of garlic 1 could be grown to a length of, for example, about 25 cm.

  The sprout of this garlic 1 was softer than the sprout obtained by soil cultivation, had a mild taste and aroma, and had a high nutritional value. In addition, since it is hydroponics unlike soil cultivation, the obtained ninny sprout was extremely clean and could be provided to the market as it was by simple water washing.

(Example 2)
Lettuce was cultivated using the hydroponic cultivation apparatus 10 according to the following (1) to (6).

  In the hydroponic cultivation apparatus 10, the first drain pipe 41 was a straight pipe having a diameter of 50 mm, and the second drain pipe 42 was a straight pipe having a diameter of 25 mm.

  Moreover, the cultivation stand 22 and the cultivation block 23 which were shown in FIG. The cultivation stand 22 is made of, for example, a hard plastic plate 22A and includes a large number of holes 22B for inserting and holding the cultivation block 23 therein. The cultivation block 23 includes a porous annular body 23A that can be expanded and contracted, such as a sponge. The porous annular body 23A has a central hole 23B and a C-shaped cross section in which a slit 23C provided in a part in the circumferential direction extends to the entire length in the axial direction. The cultivation block 23 is inserted and held in the hole 22B of the cultivation table 22 with the stem 2A and root 2B of lettuce 2 loaded in the central hole 23B from the slit 23C of the porous annular body 23A. The center hole 23B of the cultivation block 23 expands elastically as the lettuce 2 grows and the stem 2A becomes thicker, and continues to hold the stem 2A without inhibiting the growth of the stem 2A.

  In addition, as shown in FIG.6 (C), the cultivation stand 22 equips each hole 22B of board 22A below with the cylindrical holder 22C longer than the plate | board thickness of this board 22A, and is equipped with the annular body of the cultivation block 23. 23A may be inserted and held in this cylindrical holder 22C.

  (1) In the timer 33, the high water level formation time t1 is set to 5 hours, and the low water level formation time t2 is set to 30 minutes.

  Of the high water level formation time t1, the high water level arrival time t1a is approximately 12 minutes, and the remainder is the high water level duration t1b. Of the low water level formation time t2, the low water level arrival time t2a is approximately 18 minutes, and the remainder is the low water level duration t2b.

  (2) The stem 2A and the root 2B of lettuce 2 are loaded into the cultivation block 23, and the cultivation table 22 into which the cultivation block 23 is inserted is shown in FIG. Arranged at the top.

  (3) The timer 33 continues to turn on the operation of the pump 31 for 5 hours of the high water level formation time t1 of the above (1). The pump 31 continues to supply the cultivation nutrient solution in the tank 30 from the water supply pipe 32 to the cultivation tank 11 at a water supply flow rate Qp. During this period, the cultivation nutrient solution supplied by the pump 31 to the cultivation tank 11 causes the water level inside the cultivation tank 11 to reach the low water level H2 of the second drainage pipe 42, and a part thereof is discharged from the second drainage pipe 42. However, the water level is made to reach the high water level H1 of the first drain pipe 41, and thereafter it is discharged by overflow from the first drain pipe 41 for a predetermined high water level duration t1b. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 is set to the high water level H1.

  At this time, as shown in FIG. 6A, the lower end of the cultivation block 23 inserted in the cultivation table 22 arranged in the upper part of the cultivation tank 11 in the above (2) is on the water surface at the above-mentioned high water level H1. It is set to immerse directly under the water surface. Accordingly, the root 2B of the lettuce 2 loaded in the cultivation block 23 is located in the water of the cultivation nutrient solution L at the high water level H1 inside the cultivation tank 11, and absorbs the cultivation nutrient solution L, It grows in the water.

  (4) The timer 33 turns off the operation of the pump 31 after 5 hours of the high water level formation time t1 in (3) above, and turns off the operation of the pump 31 in the low water level formation time in (1) above. Continue for 30 minutes at t2. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 reaches from the high water level H1 of the first drain pipe 41 to the low water level H2 of the second drain pipe 42, and then the desired low water level. The low water level H2 is maintained for the duration t2b.

  At this time, the root 2B of lettuce 2 loaded in the cultivation block 23 on the cultivation table 22 is located in the air above the cultivation nutrient solution L at the low water level H2 inside the cultivation tank 11, While being prevented, it can be moderately stressed by water shortages.

  (5) The timer 33 turns off the operation of the pump 31 after 30 minutes of the low water level formation time t2 of (4) above, and turns on the operation of the pump 31, and turns on the high water level formation time of the above (1). Continue for 5 hours at t1. Thereby, the water level of the cultivation nutrient solution L inside the cultivation tank 11 is changed from the low water level H2 of the second drain pipe 42 to the high water level H1 of the first drain pipe 41 in the same manner as the above (3). And then maintain that high water level H1 for the desired high water level duration t1b.

  At this time, the root 2B of the lettuce 2 loaded in the cultivation block 23 on the cultivation table 22 is again located in the water of the high water level H1 inside the cultivation tank 11, and is in the air in the above (4). The cultivation nutrient solution L is absorbed at a stretch so as to eliminate the stress caused by being. As a result, lettuce 2 is rapidly promoted to grow leaf 2C.

  (6) After that, intermittent supply and water level adjustment of the cultivation nutrient solution L of (4) and (5) above are repeated, and the air condition of (4) and the underwater condition of (5) above are applied to the root 2B of lettuce 2. By alternately and repeatedly applying, lettuce 2 could be grown as shown in FIG.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, the hydroponic cultivation apparatus 10 includes three or more drain pipes 41, 42, 43... (FIG. 2), and selects two of the drain pipes 41, 43, for example, and selects the higher drain pipe. 41 can be used as the first drain pipe, and the lower drain pipe 43 can be used as the second drain pipe. For the drain pipes 42 that are not selected, the inlet at the upper end is closed.

  According to the present invention, with a simple configuration, the roots are alternately positioned in the water of the cultivation nutrient solution and in the air above the cultivation nutrient solution in accordance with the growth of the plant supported on the cultivation bed at the top of the cultivation tank. Moreover, intermittent supply and water level adjustment of the cultivation nutrient solution inside the cultivation tank can be performed at a timely timing.

DESCRIPTION OF SYMBOLS 10 Hydroponic cultivation apparatus 11 Cultivation tank 20 Cultivation bed 21 Cultivation basket 22 Cultivation stand 23 Cultivation block 30 Tank 31 Pump 32 Water supply pipe 33 Timer 41 First drain pipe 42 Second drain pipe

Claims (5)

Place the cultivation bed that supports the plant on the top of the cultivation tank,
With a water supply pipe that supplies the cultivation nutrient solution pumped by the pump to the inside of the cultivation tank,
In the hydroponic cultivation apparatus comprising a drain pipe for discharging the cultivation nutrient solution inside the cultivation tank,
As drainage pipes for discharging the cultivation nutrient solution inside the cultivation tank, the first and second drainage pipes are provided,
The high water level that is the drainage level of the first drain pipe is set higher than the low water level that is the drain level of the second drain pipe, and the drain flow rate of the first drain pipe is set larger than the drain flow rate of the second drain pipe. And
The drainage flow rate of the first drainage pipe is set larger than that of the feedwater pipe when the pump is on, and the drainage flow rate of the second drainage pipe is set small.
By controlling on / off of the pump operation with a timer,
The water level inside the cultivation tank is set to the high water level by continuing the pump operation on for the high water level formation time determined by the timer, and the root of the plant supported on the cultivation bed is set to the high water level. While making it possible to position the cultivation nutrient solution in water,
The water level inside the cultivation tank is set to the low water level by continuing the pump operation off for the low water level formation time determined by the timer, and the root of the plant supported on the cultivation bed is set to the low water level. To be located in the air above the cultivation nutrient solution,
A hydroponic cultivation apparatus characterized by intermittent supply and water level adjustment of a cultivation nutrient solution inside a cultivation tank.   The high water level formation time is determined between the high water level and the low water level inside the cultivation tank due to the flow rate difference between the feed water flow rate of the pump and the drainage flow rate of the second drain pipe when the pump operation is switched from off to on. Desirable to keep the water level inside the cultivation tank at the high water level at the high water level arrival time when the water level inside the cultivation tank reaches the high water level from the low water level, which is the value obtained by dividing the water storage amount between The hydroponic cultivation apparatus according to claim 1, which is calculated by adding the high water level durations.   The low water level formation time excludes the amount of water stored between the high water level and the low water level inside the cultivation tank by the drainage flow rate of the second drain pipe when the pump operation is switched from on to off. The desired low water level duration to keep the water level inside the cultivation tank at the low water level is added to the low water level arrival time when the water level inside the cultivation tank reaches the low water level from the high water level. The hydroponic cultivation apparatus according to claim 1, which is calculated as follows.   The hydroponic cultivation apparatus according to any one of claims 1 to 3, wherein the cultivation bed is made of a cultivation basket having a mesh shape.   The hydroponic cultivation apparatus in any one of Claims 1-3 in which the said cultivation bed has a cultivation block which consists of a porous annular body which can be expanded and contracted.

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