AU2018229982A1

AU2018229982A1 - Rice seedling cultivation device and rice seedling cultivation method

Info

Publication number: AU2018229982A1
Application number: AU2018229982A
Authority: AU
Inventors: Junya Fuse
Original assignee: Mitsubishi Chemical Agri Dream Co Ltd
Current assignee: Mitsubishi Chemical Agri Dream Co Ltd
Priority date: 2017-03-07
Filing date: 2018-01-23
Publication date: 2019-09-19
Also published as: CN110381729A; CN115053723A; JPWO2018163629A1; WO2018163629A1; JP7382229B2

Abstract

A rice seedling cultivation device comprising an illumination device 13, the rice seedling cultivation device cultivating rice seedlings in multilevel-shelf plant growing devices 3-8, wherein the rice seedling cultivation device is characterized in that the illumination device 13 comprises a semiconductor light source and a resin cover 13b that diffuses light from the semiconductor light source, and the luminous flux of the illumination device 13 output from the illumination device is 17000 lumens or more per 1 m

Description

DESCRIPTION

Title of Invention: SEEDLING CULTIVATION APPARATUS AND

SEEDLING CULTIVATION METHOD

Technical Field [0001] The present invention relates to a cultivation apparatus and a cultivation method for cultivating seedlings, and more specifically relates to a seedling cultivation apparatus and a seedling cultivation method for cultivating seedlings that easily survive and grow well even when transplanted to a field using sunlight. In the present invention, seedlings refer to, for example, young plants used to be transplanted to other cultivation places such as greenhouses and fields.

Background Art [0002] Hitherto, in the case of horticultural crop farmers, in-house production has been mainstream for the production of seedlings of various plants. However, the technique required to produce seedlings of various plants is so advanced that it is time-consuming and complicated, as it is commonly referred to as Nae-Hansaku (meaning that a seedling is equivalent to about half of harvest), and thus it has been changed to use purchased seedlings. This is due to the progress of aging of farmers and shortage of labor in recent years, the progress of commercialization and expansion of horticultural crop farmers, and is also because labor saving by using purchased seedlings and specialization in occupation only for the production of horticultural crops tend to progress at the same time. For

11652354_1 (GHMatters) P111929.AU this reason, in recent years, the demand for purchased seedlings has been increasing, and farmers engaged in only seedling production and companies engaged in the production of seedlings have also been increasing.

[0003] Even if a seedling producer is a full-time farmer or a large-scale company, seedlings are produced by (A) a production method using sunlight outdoors, (B) a production method using sunlight in a greenhouse, (C) a production method using artificial light in a closed environment, etc.

[0004] When producing seedlings by the methods (A) and (B), the weather and the climate, especially, the amount of solar radiation and the air temperature, have a great influence. For example, strong sunlight and high temperatures in summer make seedling production itself difficult, and some plants need to be growed in a highland to avoid it. In addition, the seedling quality is affected by the outside of the greenhouse and the strong sunlight in summer causes high temperature in the greenhouse, thereby making it difficult to properly produce seedlings, reducing the commercialization rate of seedlings and the operation rate of the greenhouse, etc., and further increasing the production cost of seedlings. Thus, production and shipment of seedlings are susceptible to the weather and the climate, and stable production of uniform, high-quality seedlings is not easy.

[0005] The above seedling production method (C) is a method for stably producing high-quality seedlings, in a closed-type structure covered with an insulation wall that does not

11652354_1 (GHMatters) P111929.AU transmit sunlight, under an artificial environment using an air conditioning device, an artificial light source, a carbon dioxide gas fertilization device, and an irrigation device. Under the closed environment, it is possible to adjust various environmental conditions, such as light spectrum, light irradiance, lighting time, temperature, humidity, carbon dioxide gas concentration, irrigation volume, fertilizer concentration and so on, to conditions optimized for seedling growth.

[0006] In recent years, while the seedling production method (C) is spreading, cultivation using LEDs as artificial light source has been reported (Patent Literature 1, 2, and 3). However, when the seedlings raised by such a cultivation method are subsequently transplanted to a field using sunlight, the seedlings cannot adapt to rapid environmental changes, resulting in problems such as deterioration of the seedling quality due to withering, delayed growth, and dying. [0007] PTL 1: Japanese Unexamined Patent Application Publication No. 2013-062438

PTL 2: Japanese Unexamined Patent Application Publication No. 2014-061004

PTL 3: International Publication No. 2014/125714

Summary of Invention

Technical Problem [0008] It is an object of the present invention to provide a seedling cultivation apparatus and a seedling cultivation method that solve the above problems and that enable

11652354_1 (GHMatters) P111929.AU production of seedlings that allow stable and high-quality crops cultivation even when transplanted to a field using sunlight.

Solution to Problem [0009] The present invention is summarized as follows.

[1] A seedling cultivation apparatus that cultivates seedlings with a multi-tier shelf type plant cultivation device and that comprises a lighting device, wherein the lighting device includes a semiconductor light source and a cover that diffuses light from the semiconductor light source and that is made of a resin, and a luminous flux of light outputted from the lighting device per 1 m² of a cultivation surface of each shelf is 17,000 lumens or more.

[2] The seedling cultivation apparatus according to [1], wherein an average photosynthetic photon flux density of the lighting device measured at a position of 20 cm from an outer surface of the cover is 150 pmol/m²/sec or more.

[3] The seedling cultivation apparatus according to [1] or [2], wherein the cover has a height of 40 mm or less.

[4] The seedling cultivation apparatus according to any one of [ 1] to [3], wherein the semiconductor light source has a first light-emission peak wavelength within a range of 400 to 480 nm, the semiconductor light source has a second light-emission peak wavelength within 500 to 620 nm, and the second light-emission peak wavelength has a half width

11652354_1 (GHMatters) P111929.AU of 100 nm or more.

[5] The seedling cultivation apparatus according to any one of [1] to [4], wherein the cultivation apparatus is disposed in a closed-type structure, and the cultivation apparatus includes an air conditioning device in the closed-type structure, and an irrigation device for irrigating the seedlings.

[6] A seedling cultivation method using the seedling cultivation apparatus according to any one of [1] to [5]. Advantageous Effects of Invention [0010] According to the present invention, it is possible to produce seedlings that allow stable and high-quality crops cultivation even when transplanted to a field using sunlight. Brief Description of Drawings [0011] [Fig. 1] Figs, la and lb are horizontal crosssectional views of a cultivation apparatus according to an embodiment.

[Fig. 2] Fig. 2a is a cross-sectional view taken along a line Ila-IIa in Fig. la, and Fig. 2b is a cross-sectional view taken along a line Ilb-IIb in Fig. la.

	[Fig.	3]	Fig.	3	is	a	front view of a	multi-tier shelf
type	plant	cultivation device according to	an embodiment.
	[Fig.	4]	Fig.	4	is	a	cross-sectional	view taken along a
line	IV-IV	in	Fig.	3.
	[Fig.	5]	Fig.	5	is	a	plan view of a bed of the multi-tier

shelf type plant cultivation device according to the

11652354_1 (GHMatters) P111929.AU embodiment.

	[Fig. 6]	Fig .	6	is	a	perspective	view	of	the bed	. in Fig.
5.
	[Fig. 7]	Fig.	7	is	a	cross-sectional	view	taken	along a
line	VII-VII	in Fig	•	5.
	[Fig. 8]	Fig.	8	is	a	bottom view	of a	box	equipped with
lighting devi	ces .
	[Fig. 9]	Fig.	9	is	a	cross-sectional	view	taken	along a
line	IX-IX in	Fig.	8 .

[Fig. 10] Fig. 10 is a cross-sectional view of a bed of a multi-tier shelf type plant cultivation device according to another embodiment.

Description of Embodiments [0012] The seedling cultivation apparatus of the present invention is a cultivation apparatus that cultivates seedlings with a multi-tier shelf type plant cultivation device and that includes a lighting device. The lighting device includes a semiconductor light source covered with a cover that is made of a resin and that diffuses light to a main body lower surface, and a luminous flux of light outputted from the lighting device, per 1 m² of a cultivation surface of each tier of shelf, is 17,000 lumens or more.

[0013] For the lighting device, it is important that the luminous flux of light outputted from the lighting device, per 1 m² of the cultivation surface of each tier of shelf , is 17,000 lumens or more, and the luminous flux is preferably 20,000 lumens or more, more preferably 22,000 lumens or more,

11652354_1 (GHMatters) P111929.AU further preferably 24,000 lumens or more, and particularly preferably 27,000 lumens or more.

[0014] The upper limit of the luminous flux of light outputted from the lighting device, per 1 m² of the cultivation surface of each tier of shelf, is not particularly limited, but is preferably 110,000 lumens or less, more preferably 90,000 lumens or less, and further preferably 70,000 lumens or less. When the luminous flux of light outputted from the lighting device, per 1 m² of the cultivation surface of each tier of shelf, is set to be within the above range, it is possible to produce seedlings that stably grow even when transplanted to a field or a greenhouse using sunlight after end of seedling raising.

[0015] The shape of the lighting device of the present invention is not particularly limited, but, in consideration of simplification of a method for mounting the lighting device to the cultivation apparatus or maintenance such as replacement of the lighting device, it is preferable to mount a long lighting device along the longitudinal direction of a cultivation shelf.

[0016] In the case of mounting a plurality of long shape lighting devices, a total luminous flux of each lighting device is preferably 5,000 lumens or more, more preferably 5,500 lumens or more, further preferably 6,000 lumens or more, and particularly preferably 6,500 lumens or more.

[0017] An average photosynthetic photon flux density of the lighting device measured at a position of 20 cm from a cover

11652354_1 (GHMatters) P111929.AU outer surface (light exit surface) is preferably 150 pmol/m²/sec or more, more preferably 170 pmol/m²/sec or more, and further preferably 200 pmol/m²/sec or more. When the average photosynthetic photon flux density measured at a position of 20 cm from the cover outer surface (light exit surface) is set as described above, it is possible to make the photosynthesis of seedlings more efficient and to more inhibit occurrence of spindly growth or weak growth. Thus, it is preferable to set the average photosynthetic photon flux density as described above.

[0018] The cover, made of the resin, of the lighting device has a cover height (H in Fig. 9) of preferably 40 mm or less, more preferably 35 mm or less, further preferably 30 mm or less, and particularly preferably 25 mm or less. When the height of the cover is set to be within the above range, it is possible to ensure a large height of each tier of a multi-tier cultivation shelf, and it is possible to install more tiers on same height shelf.

[0019] The semiconductor light source of the lighting device preferably has a first light-emission peak wavelength within the range of 400 to 480 nm. When the semiconductor light source of the lighting device preferably has a first lightemission peak wavelength within the range of 400 to 480nm, it is possible to inhibit internode elongation of seedlings and to cultivate firm seedlings with a short hypocotyl.

[0020] Having a second light-emission peak wavelength within

500 to 620 nm is preferable, the second light-emission peak

11652354_1 (GHMatters) P111929.AU wavelength is more preferably within the range of 500 to 610 nm and further preferably within the range of 500 to 600 nm, and the second light-emission peak wavelength has a half width of preferably 100 nm or more, more preferably 120 nm or more, and further preferably 140 nm or more. When the wavelength of the semiconductor light source of the lighting device is set to be within the above range, it is possible to inhibit occurrence of an abnormality in the morphogenesis of seedlings and to cultivate normal seedlings.

[0021] The semiconductor light source of the lighting device of the present invention is not particularly limited, and it is possible to use organic light-emitting diodes, laser diodes, LEDs, etc. Considering the consumption of power, it is preferable to use LEDs.

[0022] In the seedling cultivation apparatus of the present invention, a 20% uniformity ratio of the average photosynthetic photon flux density on the cultivation surface on each tier of cultivation shelf (the ratio of the area of a cultivation surface falling within +20% of the average photosynthetic photon flux density) is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more. When the 20% uniformity ratio of the average photosynthetic photon flux density at each tier of cultivation shelf is set to be within the above range, variations in the growth rate of seedlings to be cultivated on each tier are reduced, so that it is possible to produce more uniform seedlings .

11652354_1 (GHMatters) P111929.AU [0023] The 20% uniformity ratio of the average photosynthetic photon flux density (the ratio of the area of a cultivation surface falling within +20% of the average photosynthetic photon flux density) is a result of measurement being made when a measurement surface is divided into 5 cm meshes in measurement at a position of 20 cm from the light source. The measurement of the average photosynthetic photon flux density is data obtained when a measurement floor surface is made into a black body with a reflectance of 5% or less.

[0024] Preferably, the seedling cultivation apparatus of the present invention is disposed in a closed-type structure, an air conditioning device is provided in the closed-type structure, and the seedling cultivation apparatus includes an irrigation device for irrigating the seedlings.

[0025] In one embodiment of the present invention, the cultivation apparatus has a growth module having an open front, and seedling raising spaces are formed by disposing seedling raising shelves in multi-tier in the vertical direction in the growth module.

[0026] A preferred embodiment of the seedling cultivation apparatus will be described with reference to Figs, la to 9 and Fig. 10. As shown in Figs, la to 2b, a plurality of (six in the shown example) box-shaped multi-tier shelf type plant cultivation devices (growth modules) 3 to 8 are installed in a room of a closed type building structure 1 that is surrounded by insulating wall surfaces such that the building structure 1 is completely shielded from light. The room 1 has a

11652354_1 (GHMatters) P111929.AU rectangular shape in a plan view, and is provided with a door 2 in one wall surface li in the lateral direction thereof. [0027] In this embodiment, the three multi-tier shelf type plant cultivation devices 3 to 5 are arranged in a row such that the open fronts thereof face in the same direction, the three multi-tier shelf type plant cultivation devices 6 to 8 are also arranged in a row such that the open fronts thereof face in the same direction, and the two rows are arranged in the room such that the open fronts oppose each other.

Hereinafter, the extension direction of the rows of the multitier shelf type plant cultivation devices 3 to 5 and 6 to 8 (the longitudinal direction of the room) is sometimes referred to as a Y direction, and the lateral direction of the room (the direction in which the multi-tier shelf type plant cultivation devices 3 to 5 and the multi-tier shelf type plant cultivation devices 6 to 8 oppose each other) is sometimes referred to as an X direction. A space A that allows one or more workers to work therein is provided between these two rows of the multi-tier shelf type plant cultivation devices 3 to 5 and 6 to 8. A space B having a width of about 50 to 500 mm is provided between wall surfaces lj and lk in the longitudinal direction of the room and the back of the respective multi-tier shelf type plant cultivation devices 3 to 8, thereby forming a passage for air that has passed through the multi-tier shelf type plant cultivation devices 3 to 8 .

[0028] One end side of each of the rows of the multi-tier

11652354_1 (GHMatters) P111929.AU shelf type plant cultivation devices 3 to 5 and 6 to 8 is in contact with a building wall surface lh at the side opposite to the door 2. The other end side of each of the rows of the multi-tier shelf type plant cultivation devices 3 to 5 and 6 to 8 is slightly separated from the wall surface li at the door 2 side.

[0029] When heated air flows into the space A from the separation space at the wall surface li at the door 2 side described above, it is also possible to provide a control plate for inhibiting this flow, at an appropriate location.

[0030] If an air curtain is mounted at the inner side of the door 2 for entering and leaving the room, it is possible to prevent outdoor air from entering the room when a worker enters or leaves the room. Thus, it is preferable to mount such an air curtain.

[0031] In this embodiment, the plant cultivation apparatuses are seedling cultivation apparatuses. As shown in Figs. 3 and 4, each of the multi-tier shelf type plant cultivation devices 3 to 8 includes a box-shaped structure having a pedestal 3c, left and right side panels 3a, a back panel 3b on the back, a top panel 3e on the top, and an open front. Within the boxshaped structure, a plurality of seedling raising shelves 12 are arranged in multiple tiers at regular intervals in the vertical direction.

[0032] Preferably, the height of each of the multi-tier shelf type plant cultivation devices 3 to 8 is about 2,000 mm that is a height that allows a worker to work, and the width

11652354_1 (GHMatters) P111929.AU of each of the seedling raising shelves 12 is a width that allows a plurality of plug-trays, which are made of a resin and in which several tens to several hundreds of cells (small pots) are arranged in a lattice manner, to be aligned and placed thereon, and that allows the temperature and the humidity in the space above each shelf 12 to be adjusted to be constant. For example, preferably, the width of each of the seedling raising shelves 12 is about 1,000 mm to 2,000 mm, and the depth of each of the seedling raising shelves 12 is 500 mm to 1,000 mm. A plurality of plug-trays 40 (see Fig. 7) are substantially horizontally placed on each seedling raising shelf 12. The dimensions of one plug-tray are generally a width of about 300 mm and a depth of about 600 mm.

[0033] The seedling raising shelf 12 at the lowermost tier is placed on the pedestal 3c. The levelness of the seedling raising shelves 12 is allowed to be adjusted by an adjuster (not shown) provided to the pedestal 3c.

[0034] Each of the seedling raising shelves 12 is provided with a later-described irrigation device 30.

[0035] A box 14 is mounted on the lower surface of each of the top panel 3e and the seedling raising shelves 12 at the second tier or higher from the bottom, and a plurality of (three in this embodiment) lighting devices 13 are mounted to the box 14. The lighting devices 13 are configured to irradiate light to the plants that grow on the plug-trays 40 on the seedling raising shelves 12. In this embodiment, the boxes 14 other than that at the uppermost portion are attached

11652354_1 (GHMatters) P111929.AU to the lower surfaces of later-described cultivation beds 31.

[0036] The light source of each lighting device 13 is preferably a semiconductor light source such as an LED.

[0037] Figs. 8 and 9 show the details of the configurations of the lighting devices 13. Fig.

is a bottom view of the box including the lighting devices

13, and Fig.

sectional view taken along a line

IX-IX in Fig.

bottom plate 14b of the box 14 is provided with narrow and long openings 14a, and the lighting devices 13 are mounted so as to be fitted into the openings 14a.

Each lighting device 13 has a case 13c that is mounted in the box so as to face the opening 14a, a semiconductor light source

13a that is mounted in the case 13c, a cover 13b that covers the lower surface of the case 13c and that is made of a synthetic resin, etc. The cover 13b is detachably attached to the case 13c. A switch 13s is mounted on the lower surface of the box 14.

is a box-like body having a rectangular top plate 14t and a rectangular bottom plate 14b.

[0040] in this embodiment) the openings

14a are provided so as to extend in a direction parallel to the long side of the rectangular bottom plate 14b.

The case

13c is an elongated long box having an open lower surface, and a lower end thereof is fitted into the opening

14a.

[0041]

Although not shown, the semiconductor light source

13a mounted in the case 13c has a substrate, a plurality of

11652354_1 (GHMatters) P111929.AU

LEDs that are mounted as semiconductor light sources on the substrate, and a circuit for driving the LEDs. The substrate extends in the longitudinal direction of the case 13c, and the LEDs are mounted so as to be spaced apart from each other in the longitudinal direction.

[0042] A gap of about 3 to 30 mm is provided between the case 13c and the top plate 14t of the box 14. Heat generated in the lighting device 13 is transferred to the bottom plate 14b and dissipated from the bottom plate 14b. That is, the heat is transmitted to air flowing through the seedling raising space below the lighting device 13.

[0043] Since the gap is provided between the case 13c and the box top plate 14t as described above, heat transmitted from the light source or the driving circuit therefor to the top plate 14t is extremely low. Thus, a nutrient flowing on the cultivation bed 31 and the root zones of plants planted in the plug-tray 40 are prevented from being heated by heat of each lighting device 13.

[0044] The cover 13b is a long curved plate body that has a circular arc or substantially elliptical vertical crosssectional shape and that extends along the opening 14a. The cover 13b diffuses light from the LEDs and emits the light downward. In this embodiment, the lower surface of the cover 13b is a light exit surface. The cover 13b is mounted so as to be convex downward. The protrusion height H of the cover 13b from the bottom plate 14b is 40 mm or less.

[0045] As shown in Fig. 4, vents are provided in the back

11652354_1 (GHMatters) P111929.AU panel 3b behind the spaces (seedling raising spaces) between the respective seedling raising shelves 12 and between the seedling raising shelf 12 at the uppermost stage and the top plate panel 3e, and air fans 15 are attached to the respective vents .

[0046] Since the air fans 15 are provided at the back side of the respective seedling raising spaces as described above, airflow in the respective seedling raising spaces becomes uniform, which is preferable.

[0047] An air conditioning device 9 having a function of adjusting the temperature and the humidity of the air within the room and circulating the air adjusted in temperature and humidity to setting conditions, is installed at an upper portion of the room. The air conditioning device 9 includes an air conditioning device body (air conditioner) 9A having a heat exchanger, and a wind direction control plate 10 attached to the lower surface of the air conditioning device body 9A. A compressor of the air conditioning device body 9A is installed outside the building structure 1.

[0048] In this embodiment, the air conditioning device body 9A is located at an upper portion of the center of the room in a plan view of the room. An intake port 9a of the air conditioning device body 9A is provided in the lower surface of the air conditioning device body 9A, and an opening 10a is provided in the wind direction control plate 10 at a position overlapping the intake port 9a.

[0049] The air conditioning device body 9A is attached to a

11652354_1 (GHMatters) P111929.AU ceiling It of the building structure and has a structure in which the side surfaces thereof are exposed within the room. A discharge port 9b is provided in each of the four side surfaces of the air conditioning device body 9A.

[0050] In the wind direction control plate 10, the peripheral edge portion of the opening 10a overlaps the peripheral edge of the intake port 9a of the air conditioning device body 9A. The size of the opening 10a is equal to or larger than that of the intake port 9a.

[0051] The wind direction control plate 10 is supported on the ceiling It by means of a hanging tool (not shown).

[0052] One end side in the Y direction of the wind direction control plate 10 is in contact with the wall surface lh. The other end side in the Y direction of the wind direction control plate 10 extends to the wall surface li side further than the multi-tier shelf type plant cultivation devices 3 to 5 and 6 to 8, but is slightly separated from the wall surface li. A standing plate lOr is provided upright over the overall length of the side portion at the other end side of the wind direction control plate 10, and the upper end of the standing plate lOr is in contact with the ceiling It.

[0053] The wind direction control plate 10 extends in the X direction to the space between the ceiling It and the upper surfaces of the multi-tier shelf type plant cultivation devices 3 to 8.

[0054] As shown in Fig. 2a, both ends in the X direction of the wind direction control plate 10 are located at the

11652354_1 (GHMatters) P111929.AU vertically upper side of the fronts at the space A side of the multi-tier shelf type plant cultivation devices 3 to 5 and the multi-tier shelf type plant cultivation devices 6 to 8, or at the back side, that is, at the space B side, with respect thereto. The distances L in the horizontal direction between both ends in the X direction of the wind direction control plate 10 and the fronts of the multi-tier shelf type plant cultivation devices 3 to 5 and 6 to 8 may each be 0 mm, but are each preferably 30 mm or more, further preferably 40 mm or more, further preferably 90 mm or more, and further preferably 140 mm or more.

[0055] In this embodiment, the spaces between both ends in the X direction of the wind direction control plate 10 and the ceiling It are air outlets 9f of the air conditioning device 9. The air outlets 9f may overlap the fronts of the multi-tier shelf type plant cultivation devices 3 to 8 in a plan view of the cultivation apparatus, but are preferably located at positions backward of the fronts by the distances L.

[0056] In this embodiment, the intake port 9a of the air conditioning device body 9A is an air inlet of the air conditioning device 9. The air inlet is located at the front side, that is, at the space A side, with respect to the fronts of the multi-tier shelf type plant cultivation devices 3 to 8 in a plan view of the cultivation apparatus.

[0057] When the air fans 15 are operated, circulating flow of air as shown by arrows in Fig. 2a occurs in the room. That is, air that has been adjusted in temperature and humidity by the

11652354_1 (GHMatters) P111929.AU air conditioning device 9 is sucked into the seedling raising spaces at the respective tiers of the seedling raising shelves 12 from the space A at the open front side of the multi-tier shelf type plant cultivation devices 3 to 8, is discharged backward of the back panel 3b from the air fans 15, flows upward through the space B between the back of the back panel 3b and the building wall surface, passes through a space C above the multi-tier shelf type plant cultivation devices 3 to 8, is mixed with air blown out from the air conditioning device 9 to be adjusted in temperature and humidity, and then is blown out through the space between the wind direction control plate 10 and the multi-tier shelf type plant cultivation devices 3 to 8 into the space A at the open front side of the multi-tier shelf type plant cultivation devices 3 to 8 again.

[0058] Moreover, part of air that is about to flow into the space A through the space between the wind direction control plate 10 and the multi-tier shelf type plant cultivation devices 3 to 8 flows through the opening 10a, is sucked through the intake port 9a of the air conditioning device body 9A, is adjusted in temperature and humidity, and then is blown out from the air outlets 9f through the discharge ports 9b. [0059] In the case where the two rows of the multi-tier shelf type plant cultivation devices 3 to 5 and the multi-tier shelf type plant cultivation devices 6 to 8 are arranged such that a working space is formed therebetween as in Figs, la to 2b, the working space also function as the space A for air

11652354_1 (GHMatters) P111929.AU circulation, so that effective circulating flow is formed.

[0060] When the circulating flow passes through the respective seedling raising spaces of the multi-tier shelf type plant cultivation devices 3 to 8, water vapor evaporated from the irrigation devices, media, plants, etc., or heat dissipated from the lighting devices 13 is accompanied by the circulating flow, and the circulating flow is constantly adjusted in temperature and humidity and circulated by the air conditioning device 9, whereby it is possible to maintain the interior of the room in an temperature-humidity environment optimized for plant growth. The flow rate of air flowing thought each seedling raising space is preferably 0.1 m/sec or more, more preferably 0.2 m/sec or more, and further preferably 0.3 m/sec or more. If the speed of airflow is excessively high, a problem may arise in plant raising. Thus, generally, the speed of airflow is preferably 2.0 m/sec or less .

[0061] In this embodiment, the airflow is sent from the front of each seedling raising space through the fan 15 to the space B at the shelf back side in a negative pressure state, but, conversely, may be sent from the shelf back side to the front side in a positive pressure state. However, when the airflow is sent from the front side to the shelf back side in a negative pressure state, the airflow in each seedling raising space becomes more uniform.

[0062] In this embodiment, a shelf plate of each seedling raising shelf 12 is composed of the cultivation bed 31 of the

11652354_1 (GHMatters) P111929.AU irrigation device (bottom surface irrigation device) 30, and irrigation is performed from the bottom surfaces of the plugtrays 40 placed on the cultivation bed 31. An example of the configuration of the irrigation device 30 will be described with reference to Figs. 5 to 7.

[0063] The irrigation device 30 includes the square cultivation bed 31 having a bottom plate 31d on which side walls 31a, 31b, and 31c are provided upright at a back side, and left and right sides thereof. A drainage groove 32 is provided at the front side of the cultivation bed 31 at which no side wall is present, so as to be connected to the bottom plate 31d, and a drainage port 32a is formed at one end of the drainage groove 32. The drainage groove 32 and the bottom plate 31d are partitioned by a weir 34, and notches 34a are formed at both end portions of the weir 34 such that the nutrient solution flows out through the notche 34a at both end portions of the weir 34 to the drainage groove 32. In addition, a water supply pipe 33 for supplying the nutrient into the cultivation bed 31 is provided along the side wall 31a at the back side of the cultivation bed 31, and the nutrient is supplied onto the bed 31 through a plurality of small holes 33a provided in the water supply pipe 33.

[0064] A plurality of ribs 35 having a height of about 7 mm are provided on the upper surface of the cultivation bed bottom plate 31d so as to extend toward the drainage groove 32 so as to be parallel to each other such that the plug-trays 40 are allowed to be placed on these ribs 35.

11652354_1 (GHMatters) P111929.AU [0065] The irrigation device 30 is dimensioned such that, when the cultivation beds 31 are placed on each of the seedling raising shelves 12 of the multi-tier shelf type plant cultivation devices 3 to 8 as shown in Fig. 4, the drainage groove 32 protrudes from the open front of each of the cultivation devices 3 to 8. Since the drainage groove 32 protrudes from the open front of each cultivation device, the nutrient discharged through the drainage port 32a of the drainage groove 32 of the cultivation bed 31 placed at each of the tiers of the seedling raising shelves 12 is easily collected and discharged to the outside of the building structure 1.

[0066] When the nutrient is continuously supplied through the small holes 33a provided in the water supply pipe 33 of the irrigation device 30, the nutrient is dammed up by the weir 34 and accumulates up to a predetermined level to come to a pool state. While the nutrient is supplied from the water supply pipe 33, the nutrient flows out from the notches 34a to the drainage groove 32 little by little. For example, a pool state at a level of about 10 to 12 mm is preferably maintained in the cultivation bed 31 by adjusting an amount of the nutrient supplied and an amount of the nutrient flowing out from the notches 34a. Water is sucked up through cell holes 42, which are formed in the bottom surfaces of respective cells 41 of the plug-trays 40 placed on the ribs 35, to a medium within the cells due to capillary action, so that the medium within all the cells 41 is brought into a water

11652354_1 (GHMatters) P111929.AU saturation state in a short time.

[0067] The box 14 is attached to the lower surface of the bottom plate 31d of the cultivation bed 31. In this embodiment, the top plate 14t of the box 14 is directly in contact with the lower surface of the cultivation bed 31, but a spacer or a heat insulating material may be interposed therebetween .

[0068] In the irrigation device 30, the upper surface of the bottom plate 31d of the cultivation bed 31 is inclined in the direction toward the drainage groove 32 as shown in Fig. 7. Accordingly, it is possible to discharge the nutrient to the drainage groove 32 in a short time at the time of stop of irrigation. In addition, in the case where the upper surface of the bottom plate 31d is inclined, it is possible to horizontally maintain the plug-trays 40 placed on the ribs 35, by changing the heights of the ribs 35 such that top portions 35a of the ribs are horizontal.

[0069] Fig. 10 shows another example of the irrigation device used in the present invention, and the components identical to those in Fig. 5 to Fig. 7 are designated by the same reference numbers. In this irrigation device 30', an under tray 50 is interposed between the cultivation bed bottom plate 31d and the plug-tray 40 when placing the plug-tray 40 on the cultivation bed bottom plate 31d. The under tray 50 has rigidity that allows the plug-tray 40 in which a medium is put in each cell 41 to be supported, a plurality of small holes 51 are formed in a bottom wall surface thereof, and a plurality

11652354_1 (GHMatters) P111929.AU of projections 52 are formed on a back surface thereof. These projections 52 function as a gap maintaining means for maintaining a gap between the cultivation bed bottom plate 31d and the bottom surface of the plug-tray 40 when the plug-tray 40 is put in the cultivation bed together with the under tray 50 .

[0070] In the irrigation device 30' in Fig. 10 as well, when a nutrient is supplied from the supply pipe 33 and come to a pool state at a predetermined level, the nutrient is introduced through the small holes 51 of the under tray 50 into the under tray 50, and water is sucked up through the cell holes 42 formed in the bottom surface of each cell 41 of the plug-tray 40, into the medium within the cells due to capillary action.

[0071] In Fig. 10 as well, a box 14 including lighting devices 13 is attached to the lower surface of the cultivation bed bottom plate 31d.

[0072] The plug-tray 40 to be placed on the cultivation bed is obtained by arranging several tens to several hundreds of cells 41 in a lattice manner and integrating the cells 41 into a tray shape, as described above. The dimensions of one plug-tray are a width of about 300 mm and a depth of about 600 mm, but are not limited thereto.

[0073] In order to artificially supply carbon dioxide gas to be consumed by seedlings through photosynthesis, as shown in Fig. 1, liquefied carbon dioxide gas cylinders 16 are installed outside the building structure 1, and carbon dioxide

11652354_1 (GHMatters) P111929.AU gas is supplied from the carbon dioxide gas cylinders 16 such that the concentration of carbon dioxide gas in the room measured by a carbon dioxide concentration measuring device becomes uniform.

[0074] By raising seedlings using this seedling cultivation apparatus, it is possible to automatically adjust environmental conditions such as light quantity, temperature, humidity, carbon dioxide gas, moisture, etc. suitable for growth of the seedlings. In addition, since all the seedlings in each seedling raising shelf are able to grow under the same environment, it is possible to enhance the uniformity of the quality of the obtained seedlings.

[0075] In this embodiment, since the air outlets 9f of the air conditioning device 9 are located at the back side away from the fronts of the multi-tier shelf type plant cultivation devices 3 to 8 by 30 mm or more, air that has passed through the multi-tier shelf type plant cultivation devices 3 to 8 (growth modules) and been heated and air cooled by the air conditioning device 9 flow into the space A in a state of being mixed together. Accordingly, the air flowing into the space A becomes uniform-temperature air and is sucked into the respective multi-tier shelf type plant cultivation devices 3 to 8 .

[0076] If air cooled by the air conditioning device 9 directly flows into the space A, partially cold air is sucked through the fronts of the multi-tier shelf type plant cultivation devices 3 to 8. Thus, temperature unevenness

11652354_1 (GHMatters) P111929.AU occurs among the multi-tier shelf type plant cultivation devices 3 to 8, so that plant growth does not become uniform. [0077] In this embodiment, since the air conditioning device body 9 and the wind direction control plate 10 are integrated with each other, it is not necessary to install many duct pipes, etc., which is preferable.

[0078] In the multi-tier shelf type plant cultivation device, heat of the lighting devices 13 is transmitted to the box bottom plate 14b, which also serves as a reflection plate, and is transferred from the bottom plate 14b to air flowing through the seedling raising space. The heat transferred from the lighting devices 13 to the cultivation bed 31 at the upper side is significantly low. Thus, the temperature of the nutrient on the cultivation bed 31 is controlled within a predetermined range.

[0079] In the present invention, a ratio Wb/Wa of the total cooling capacity (Wb) of all the air conditioning devices 9 to the total power consumption (Wa) of all the lighting devices 13 is preferably 1 to 5, more preferably 1 to 4, further preferably 1 to 3, and particularly preferably 1 to 2. By setting Wb/Wa to be within the above range, it is possible to keep the environment within the closed space appropriate and constant, and further it is also possible to reduce the environmental change due to turning on/off the air conditioner. Wb/Wa is represented by A in the following equation when the power consumption per lighting device is denoted by Ws, the number of lighting devices is denoted by n,

11652354_1 (GHMatters) P111929.AU the cooling capacity of one air conditioning device is denoted by Wk, and the number of air conditioning devices installed is denoted by m.

[0080] A = Wb/Wa = (Wkxm) / (Wsxn) m: number of air conditioning devices n: number of lighting devices [0081] The above embodiment is an example of the present invention, and the present invention is not limited thereto. For example, the size of the room and the number of multi-tier shelf type plant cultivation devices installed may be those other than the above. In addition, the air conditioning device body may be installed at a position other than the center. Two or more air conditioning device bodies may be installed, but the number of air conditioning device bodies is preferably as small as possible.

Examples [0082] [Example 1]

Using the cultivation apparatus having the structure shown in Figs. 1 to 9, the air temperature within the apparatus was controlled to be 16 to 25°C, and spinach seedlings were cultivated.

[0083] The installation mode of the lighting devices 13 are as follows.

[0084] Size of shelf (cultivation surface): a width of 1.2 m, a depth of 0.6 m

Number of lighting devices 13 per tier of shelf: 3 (as

11652354_1 (GHMatters) P111929.AU shown)

Total luminous flux of one lighting device 13: 6,900 lumens

Luminous flux of light outputted from lighting devices per 1 m² of cultivation surface of each tier of shelf: 28,750 lumens

First light-emission peak wavelength of LED light emitter:

450 nm

Second light-emission peak wavelength of LED light emitter: 590 nm (half width: 150 nm)

Height H of cover 13b: 20 mm

Average photosynthetic photon flux density of cultivation surface: 205 qmol/m²/sec

20% uniformity ratio of photosynthetic photon flux density of cultivation surface: 84%

Total cooling capacity (Wb) of air conditioning devices:

5.6 kW

Total power consumption (Wa) of lighting devices: 3.2 kW [0085] As a result, it is recognized that it is possible to produce seedlings that allow stable and high-quality crops cultivation even when transplanted to a field using sunlight. [0086] Although the present invention has been described in detail by means of the specific embodiment, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the present invention.

This application is based on Japanese Patent Application

11652354_1 (GHMatters) P111929.AU

No. 2017-042967 filed on March 7, 2017, which is incorporated by reference in its entirety.

Reference Signs List [0087] 1 closed type building structure

3~8 multi-tier shelf type plant cultivation device

3a side panel

3b back panel

3c pedestal

3e top panel air conditioning device

9A air conditioning device body

9a intake port

9b discharge port

9f air outlet wind direction control plate

10a opening seedling raising shelf lighting device

13a semiconductor light source

13b cover

13c case

13s switch box

14a opening air fan carbon dioxide gas cylinder

30, 30' irrigation device

11652354_1 (GHMatters) P111929.AU cultivation bed bottom plate drainage groove drainage port water supply pipe small hole weir notch rib plug-tray cell cell hole under tray small hole proj ection

11652354_1 (GHMatters) P111929.AU

Claims

CLAIMS [Claim 1]

A seedling cultivation apparatus that cultivates seedlings with a multi-tier shelf type plant cultivation device and that comprises a lighting device, wherein the lighting device includes a semiconductor light source and a cover that diffuses light from the semiconductor light source and that is made of a resin, and a luminous flux of light outputted from the lighting device per 1 m² of a cultivation surface of each tier of shelf is 17,000 lumens or more.
[Claim 2]

The seedling cultivation apparatus according to claim 1, wherein an average photosynthetic photon flux density of the lighting device measured at a position of 20 cm from an outer surface of the cover is 150 qmol/m²/sec or more.
[Claim 3]

The seedling cultivation apparatus according to claim 1 or 2, wherein the cover has a height of 40 mm or less.
[Claim 4]

The seedling cultivation apparatus according to any one of claims 1 to 3, wherein the semiconductor light source has a first light-emission peak wavelength within a range of 400 to 480 nm, the semiconductor light source has a second light-emission peak wavelength within 500 to 620 nm, and the second light-emission peak wavelength has a half width

11652354_1 (GHMatters) P111929.AU of 100 nm or more.
[Claim 5]

The seedling cultivation apparatus according to any one of claims 1 to 4, wherein the cultivation apparatus is disposed in a closed-type structure, and the cultivation apparatus includes an air conditioning device in the closed-type structure, and an irrigation device for irrigating the seedlings.
[Claim 6]

A seedling cultivation method using the seedling cultivation apparatus according to any one of claims 1 to 5.