EP0091465A1

EP0091465A1 - Improvements in or relating to hydroponic crop production

Info

Publication number: EP0091465A1
Application number: EP82903172A
Authority: EP
Inventors: Leslie Robert Tucker; Cristopher Lewis Tucker
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-10-21
Filing date: 1982-10-20
Publication date: 1983-10-19
Also published as: ES8308676A1; NO832223L; AU9056082A; GB2118416A; ES516719A0; WO1983001365A1; IT8223836A0; GB8316562D0; IT1153273B

Abstract

Un dispositif de culture hydroponique d'herbes ou d'autres cultures comprend un récipient clos possédant une base (10) avec une paroi de fond en pente (14) définissant une zone servant à recevoir et à retenir une couche de graines, sans terre, une lampe (22) à l'intérieur du couvercle du récipient (11) éclairant artificiellement l'intérieur du récipient, et des buses de pulvérisation (23) servant à arroser la couche de graines, le couvercle (11) étant amovile, ou possédant une section amovible (11a), pour permettre de sortir du récipient les plants cultivés à partir des graines. La paroi de fond (14) de la base comprend un assemblage (18) permettant de chauffer et/ou refroidir les graines pour en stimuler la croissance.A device for hydroponically growing herbs or other crops comprises a closed container having a base (10) with a sloping bottom wall (14) defining an area for receiving and retaining a layer of seeds, without soil, a lamp (22) inside the container lid (11) artificially illuminating the interior of the container, and spray nozzles (23) for watering the seed layer, the lid (11) being removable, or having a removable section (11a), to allow the plants grown from the seeds to be removed from the container. The bottom wall (14) of the base includes an assembly (18) for heating and / or cooling the seeds to stimulate their growth.

Description

"Improvements in or relating to hydroponic crop production"

The invention relates to hydroponic crop production and particularly, but not exclusively, to the hydroponic production of grass for animal feeding.

It is well known that fresh green grass contains currently unidentifiable substances, probably vitamins, which enhance the growth rates of a wide range of livestock, including poultry, pigs, sheep and cattle. These substances, often referred to as the "X Factor" occur particularly in young, growing grass, their concen- tration being lower in mature and in old grass. The X

Factor has been found not to survive storage or dehydra¬ tion and so is substantially absent from, for example, hay and silage. The value of fresh green feed in animal diet is accordingly well recognised. Fresh green grass is of course available naturally for only a comparatively short period of the. year and considerable interest has therefore been directed to its production by artificial means independent of climate. Hydroponic techniques have been employed to this

OMPI end and controlled environment hydroponic units capable of producing up to a ton of hydroponically grown grass per day are now available. Such units are highly sophisticated (and consequently very expensive), incor- porating automatically controlled heating and cooling equipment, water/nutrient circulation pumps, air circulation fans, humidifiers, lighting etc. Their operation also requires several hours of manual labour each day, since the grass is grown from seed in trays overan eight day period, the trays being manually progressed one stage further through the unit each day.

¥e have found, however, that it is possible successfully to grow grass hydroponically using very much simpler equipment. The invention therfore provides method and apparatus for the hydroponic production of grass and other crops which may be considerably simpler than existing methods and apparatus and which, in particular, are applicable to the hydroponic production of grass and other crops on a comparatively small scale. According to the invention there is provided apparatus for growing grass or other crops hydroponi¬ cally comprising an enclosed container having within the container an area for receiving and retaining a layer of seed, without soil, means for artificially illuminating the interior of the container, means for delivering water to the layer of seed, and access means for permitting removal from the container of crops grown from the seed. ^" . Where the ambient temperature is sufficiently high and the container is subjected to sufficient natural heat, it may not be necessary to provide means for heat¬ ing the layer of seed. However, preferably means are also provided for heating the layer of seed. In very hot climates, on the other hand, cooling of the seed may be necessary. Thus, the area within the container for receiving the layer of seed may incorporate a heat¬ ing and/or cooling assembly which extends over substan- tially the whole of the area over which the seed is laid. The seed may be laid on a bottom wall^'of the con¬ tainer, or on a layer of material resting on that wall, and in this case the heating and/or cooling assembly may be embodied within said bottom wall. The assembly may comprise an electrical heating element, or a plurality of tubes with means for passing a heated or cooled fluid through the tubes.

The means for artificially illuminating the interior of the container may comprise at least one lamp separated from the interior of the container by a trans¬ lucent portion. The translucent portion may comprise a translucent channel projecting into the container and containing the lamp. The channel may comprise a portion of a translucent wall of the container. The means for delivering water to the layer of seed may comprise at least one spray nozzle disposed within the container to deliver a spray of water to the interior of the container above the layer of grass seed, conduits being provided for connecting the nozzles to a source of water under pressure. Alter¬ natively, water may be supplied by a drip feed.

There are preferably provided water drainage means in the container comprising at least one drainage channel at a lowermost part of the area receiving^' the layer of seed, which channel is formed by the junction between two surfaces, for receiving the layer of seed, which are slightly angled to the horizontal. The container may comprise a lower tray-like base portion providing the area for receiving the layer of seed, and an upper cover portion which fits over the tray-like portion to provide the closed container. Preferably the area for receiving the layer of seed .is an integral part of the base portion, and may comprise the bottom wall thereof.

In an embodiment of the invention for feeding a greater number of animals there are provided a plur¬ ality of areas for receiving and retaining layers of seed, without soil, within a single container, the areas being arranged spaced one above another.

The invention also provides a method of grow¬ ing grass hydroponically wherein a layer of grass seed, without soil, is spread in a layer on an artificially heated or cooled surface within an enclosed container, and is watered while in the container. Preferably the seed is watered by delivering a spray or mist or drip of water to the interior of the container. In any of the methods and forms of apparatus described above the seed may be barley grass seed although other grasses such as oat grass may be grown. The appropriate seed may be spread to a depth- of about 1 cm to give uniform coverage.

Although, as previously mentioned, the methods and apparatus according to the invention are particularly applicable to grass production, they may also be used to propagate other crops such as lettuce, watercress, bean shoots, tomatoes, herbs, turf, etc.

The following is a detailed description, by way of an example, of embodiments of the invention, reference being made to the accompanying .diagrammatic drawings in which: Figure 1 is an exploded perspective view of apparatus according to the invention.

Figure 2 is a sectional view of the apparatus, Figure -3 is a fragmentary section through a part of the bottom wall of the apparatus, and Figure 4 is a perspective view of an alter¬ native form of apparatus.

Referring to Figures 1 and 2, the apparatus comprises a container having a tray-like base part 10 and an upper cover part 11. The two parts of the container may be formed from any suitable material. Preferably, however, they are formed from fibreglass or moulded, for example by vacuum moulding, from any other suitable plastics material. The cover part 11 is OMPI preferably translucent.

The container is generally rectangular in plan view, and the lower periphery of the cover 11 is formed with a continuous flange 12 which fits over 5 an upstanding flange 13 around the periphery of the base 10. The upstanding flange 13 may be reinforced by wooden bars 13a .integrally moulded into the plastics. For convenience, the cover 11 may be hinged to the base 10 along one side thereof so that access to the C interior of the container can be obtained by simply lifting the hinged cover. Alternatively or addition¬ ally, access to the interior may be provided by a removable section 11a in the cover 11, as shown in Figure 1. 5 The bottom wall 14 of the base 10 is formed in two parts which slope downwardly towards the centre line of the base along which are formed drainage holes 15. The drainage holes 15 communicate with a pipe 16 which is embedded in the base and leads to the exterior 0 of the container. The bottom wall 14 of the base is supported by legs 17 which may be in the form of beams extending along the whole length of the base 10. The legs 17 may be integrally moulded with the material of the base 10 and reinforced with wooden beams, as shown 5 in Figure 2, or may be formed from separate elements, mounted on the base.

Referring to Figure 3, it will be seen that the bottom wall 14 of the base 10 comprises a heating

O P and/or cooling assembly 18 sandwiched between layers 19 of fibreglass or other plastics material. A layer of heat insulating material 20 is disposed beneath the heating assembly 18 and may, for example, comprise a 1 cm layer of expanded polystyrene foam.

The heating and/or cooling assembly 18 is ^• preferably such as to provide substantially even heating or cooling over the whole of the bottom wall 14 of the base 10. In the illustrated example, the heating assem- bly is an electrical heating element formed from elec¬ tric wires, the wires preferably having a spacing of the order of 50 mm or less to provide even heating. The heating element may conveniently be of the kind where the wires are supported on a fabric base to facilitate loiuination of the heating element between the layers 19 of fibreglass during manufacture of the base.

Alternatively, the heating and/or cooling assembly may be in the form of interconnected tubes embedded in the bottom wall 14, through which tubes is passed heatedliquid or gas. Such an arrangement may be particularly advantageous in very hot environments since, as previously mentioned, in such environments it may sometimes be desirable to cool the growing grass rather than heating it, and this may be readily effected by passing a cooling fluid through the tubeswhenrequired

Although the heating element is preferably such as to provide even heating over the bottom wall of the container, the required even heating may be

OMP enhanced by covering the bottom wall, within the con¬ tainer, by a layer of heat-distributing material such as a metal sheet.

To conserve heat within the container the walls of the cover 11 may also be insulated, for example they may be double skinned walls enclosing a_,layer of air or heat insulating material, such as expanded polystyrene foam.

Preferably the heating element 18 is thermo- statically controlled, by a control unit 26, so as to provide a substantially constant predetermined tem¬ perature. Alternatively the element may be of the type which is not thermostatically controlled but which rises in temperature to a predetermined temperature at which the electrical input is balanced by the thermal losses, so as then to maintain the temperature constant.

To provide for artificial illumination within the container, there is mounted along the apex of the cover 11 a rectangular casing 21 which supports a fluorescent tube 22. The fluorescent tube lies within a channel 21a which is integrally moulded along the major central portion of the apex of the cover 11. The fluorescent tube illuminates the interior of the con- tainer through the translucent material of the channel 21a. The casing 21 itself may also be trans¬ lucent and may then, if required, bear advertising material along its sides so as to form, in effect, an illuminated sign. The interior of the casing 21 may be reflective to enhance the light output.

Since artificial illumination of the interior of the container may only be required in the hours of darkness, there may be associated with the fluorescent tube 22 a control unit, within the unit 26, which switches the lamp on and off at predetermined times or, by. incorporating a light-sensitive device, in response to the natural light level. For delivering water to the interior of the container spray nozzles 23 are mounted below opposite ends of the channel 21a. and are fed from conduits 24 which pass along and within the channel. The spray nozzles 23 are so arranged that spray injected into the container from one nozzle impinges on the spray from the other nozzle so as to disperse the spray from the two nozzles as a fine mist within the container. The nozzles 'are preferably such as to supply an adequate quantity of water under normal mains pressure, thus making it unnecessary to provide a water pump. Oper¬ ation of the nozzles 23 is preferably controlled by a time-controlled valve so that water is sprayed into the interior of the container at predetermined regular intervals, or is controlled by a moisture sensor within the container.

It is found that water may be applied to the seed by operating the nozzles at intervals within a twenty four hour period, each application having a

OMFI WIPO duration of about two minutes.

Alternatively, water may be applied to the seed in the form of a gravitational drip feed. In this arrangement water is dripped onto the bottom wall 14 of the base 10 along the opposite outer edges thereof, so that water runs downwardly over the sloping wall to the drainage holes 15, watering the seed as it does

Where a large number of pieces of apparatus are provided the associated spray systems are prefer¬ ably arranged to operate in sequence so that mains pressure may still be sufficient to provide adequate flow. It will be appreciated that if all the spray equipment were to be operated simultaneously the mains pressure might well be inadequate. However, although the use of mains water pressure is preferred, it will be appreciated that a pump could be provided in the water supply system in areas where the normal mains pressure is inadequate. A pump may also be provided in cases where a recirculating water system is desired. An advantage of a recirculating water system may be that the water, being delivered from a storage tank, may be at a slightly higher temperature than mains water would be, and this also is advantageous for fast¬ er growth of the crop. Since the conduits leading to the spray nozzles pass through the channel 21a. adjacent the fluorescent tube 22, the water passing to the nozzles 23 is heated to a certain extent by the higher temperature within the channel before it reaches the nozzles.

In use of the apparatus, seed 25, such as barley, is spread to a depth of approximately 1 cm over the bottom wall 14 of the container. The seed is. preferably laid directly on the wall 14, but it might also be laid on a layer of straw having a depth of about 1.25 cm. Within the balanced conditions iREA

OMPI of the container, the seed is heated by the heating element 18, illuminated by the lamp 22 and watered periodically from the spray nozzles 23.

Although it is not essential to supply nutrients to the seed, fertilizers could be added (e.g. dissolved in the water) in special circumstances. Thus, for example, nitrogen fertilization might be employed to increase the protein content of the grass. Other substances for enhancing the development of the seed may also be fed to the interior of the container, for example CO,, gas might be supplied.

In the summer months it may not be necessary to activate the heating element and the seed may be kept at the desired temperature by the ambient atmos- pheric temperature, particularly if the apparatus is placed in the open and exposed^* to sunlight. In this case, however, it is desirable that the material of the cover 11 should be such as to filter out or otherwise shield the seed from ultra violet rays. It will be appreciated that the apparatus may be of any convenient size and any number of pieces of apparatus may be provided, in combination, to supply the required quantity of crop. It is found that 5 cwt (250 kg) of barley grass can be grown in eight days from about 78 lbs (35.5 kg) of seed by using apparatus of the kind described.

The apparatus is particularly suitable for providing comparatively small quantities of daily feed for a single animal, or for a few small animals. To facilitate such use the interior of the base 10 may be divided into eight sections side by side along the length of the container, the sections being loaded with seed on successive days. Thus, the grass in only one section will reach maturity each day. As the grass from each section is used, the section is reseeded so that the apparatus provides a continual daily supply of grass. Where greater daily quantities of grass are required, banks of •containers may be provided, the grass in the various containers being in different stages of development.

Where a number of pieces of apparatus are required, to provide feed for a larger number of animals, the pieces of apparatus may be stacked one above another on a rack. For example, a suitable form of rack may comprise two spaced upright rectangular frames each comprising a number of vertically spaced horizontal cross-bars. Each piece of apparatus .then extends between the two frames with each end of the apparatus supported on a cross-bar of the frame. When the apparatus is stacked in this manner it will not normally be possible to open the cover 11, and access to the interior is thus provided by lifting the removable section 11a. Figure 4 shows an alternative arrangement, for feeding a large number of animals, in which a plurality of seed bases 30, similar to the base 10, are fitted one above another within a single large

OMPI WIPO container 31 having access doors 32 and 33. Instead of being similar to the base 10, each base 30 may have only a single sloping bottom wall which slopes down towards one corner of the base where drainage means are provided. Each base 30 is provided with a heater 18 as described in relation to Figures 1 and 2. The spray nozzles or drip feed for each base may be mounted on the underside of the base which is immediately above it, or may be mounted on fixed parts of the container 31.

The roof and floor of the container are heat- insulated and the doors 32 and fixed sides of the con¬ tainer are double-glazed to minimise internal temperature variations and to reduce energy requirements. The fluorescent tubes are mounted between the panes of the double-glazing to protect them from the water within the container.

The heaters, fluorescent tubes and water sprays are automatically controlled by control boxes 3 mounted within one end of the container 31.

If desired means for automatic removal of the grass from the container may be incorporated. Such means may comprise, for example, an endless chain running above and below the base wall 14 via sprockets situated at each end of the container. The chain may have teeth which project into the mat of grass so that if the sprockets are turned the mat is pulled along by movement of the chain. Alternatively, the seed may be

JR laid on an endless belt the upper stretch of which passes along the upper side of the base wall 14, part of the belt projecting beyond each end of the container. Thus, a fresh layer of seed can be applied to the projecting portion of the belt at one end of the container so as to be fed into the container as the belt is operated each day to remove the mature grass from the opposite end of the container. The apparatus thus enables con¬ tinuous grass production. The process can be automati- cally controlled by having seed delivered onto the con¬ veyor automatically at predetermined intervals controlled by a timing mechanism.

This form of fully automatic apparatus is particularly suitable for the intensive rearing of livestock. For example, the apparatus may be housed below the roof of a building in which the livestock is kept, seed being automatically delivered periodically to the apparatus^* from hoppers, and grass being auto^1*-, matically and periodically delivered from the apparatus to locations where it is accessible by the livestock.

OMPI ^~

Claims

1. Apparatus for growing grass or other crops hydroponically comprising an enclosed container having within the container an area for receiving and retaining a layer of seed, without soil, means for artificially illuminating the interior of the container, means for delivering water to the layer of seed, and access means for permitting removal from the container of crops grown from the seed.

2. Apparatus according to claim 1, comprising means for heating and/or cooling the layer of seed.

3. Apparatus according to claim 2, wherein the area within the container for receiving the layer of seed incorporates a heating and/or cooling assembly which extends over substantially the whole of the area over which the seed is laid.

4. Apparatus according to claim 3, wherein the seed is laid on -a bottom wall of the container and the heating and/or cooling assembly is embodied within said bottom wall.

5. Apparatus according to claim 4, wherein the heating and/or cooling assembly is sandwiched between layers of material making up the bottom wall of the container, a layer of heat insulating material being located beneath the heating assembly.

6. Apparatus according to any of claims^*2 to 5, wherein the assembly is a heating assembly and comprises an electrical heating element.

7. Apparatus according to any of claims 2 to 5, wherein the heating and/or cooling assembly comprises a plurality of tubes, and means are.provided for passing a heated or cooled fluid through the tubes.

8. Apparatus according to any of claims 2 to 7, wherein the walls of the container are formed with double skins separated by an air gap or by thermally insulating material.

9. Apparatus according to any of claims 2 to 8, wherein thermostatically operated controlled means are provided to control the temperature of the heating and/or cooling assembly.

10. Apparatus according to any of claims 1 to 9, wherein the means for artificially illuminating the interior of the container comprise at least one lamp separated from the interior of the container by a translucent portion.

11. Apparatus according to claim 10, wherein the translucent portion comprises a translucent channel projecting into the container and containing the lamp.

12. Apparatus according to claim 11, wherein the channel comprises a portion of a translucent wall of the container.

13. Apparatus according to any of claims 1to 12, wherein there is associated with the illuminating means a light sensitive device arranged to activate the illuminating means when the natural light reaching the interior of the container falls below a predetermined level.

14. Apparatus according to any of claims 1 to 1 . wherein the means for delivering water to the layer of seed comprise at least one spray nozzle disposed within the container to deliver a spray of water to the interior of the container above the layer of grass seed, conduits being provided for connecting the nozzle to a source of water under pressure.

15. Apparatus according to claim 14, wherein there are provided at least two nozzles so disposed that the spray from each nozzle impinges on the spray from the other nozzle.

16. Apparatus according to claim 14 or claim 15, wherein the supply of water to the nozzles is controlled by a time controlled valve mechanism or by a moisture sensor.

17. Apparatus according to any of claims 1 to 13, wherein the means for delivering water to the layer of ^* seed comprise a drip feed whereby water drips under gravity onto the layer of grass seed.

18. Apparatus according to any of claims 1 to 17, wherein there are provided water drainage means com¬ prising at least one drainage channel at a lowermost part of the area receiving the layer of seed, which channel is formed by the junction between two surfaces, for receiving the layer of seed, which are slightly angled to the horizontal.

19. Apparatus according to any of claims 1 to 18, wherein the container comprises a lower tray-like base portion providing the area for receiving the layer of seed, and an upper cover portion which fits over the tray-like portion to provide the closed container.

20. Apparatus according to claim 19, wherein the area for receiving the layer of seed is an integral part of the base portion, and comprises the bottom wall thereof.

21. Apparatus according to any of claims 1 to 20, wherein there are provided a plurality of areas for receiving and retaining layers of seed, without soil, within a single container, the areas being arranged spaced one above another.

22. Apparatus for growing grass or other crops hydroponically substantially as hereinbefore described with reference to the accompanying drawings.

23. A method of growing grass hydroponically wherein a layer of grass seed, without soil, is spread in a layer on an artificially heated or cooled surface within an enclosed container, and is watered while in the container.

24. A method according to claim 23, wherein the seed is watered by delivering a spray or mist or drip of water to the interior of the container.

25. . Grass or other crops when grown using the apparatus of any of claims 1 to 23 or using the method of claim 23 or.claim 24.

^J EA

OMPI