WO1992017053A1

WO1992017053A1 - Method and cultivation unit for plant cultivation

Info

Publication number: WO1992017053A1
Application number: PCT/FI1992/000104
Authority: WO
Inventors: Kurt Westerlund
Original assignee: Kurt Westerlund
Priority date: 1991-04-05
Filing date: 1992-04-03
Publication date: 1992-10-15
Also published as: FI911660A0

Abstract

The cultivation unit used for applying the method according to the invention comprises a growing apparatus (1), placed in a growth chamber (3), in which the cultivated plants are placed. Equipment (2) for maintaining the climate inside the growth environment is used to provide controlled conditions for cultivation in the growth chamber (3). The walls surrounding the growth chamber (3) comprise a bottom surface (4), side walls (5) and an upper surface (6). The side walls (5) and the upper surface (6) are made of a light-permeable construction, such as elements of insulating glass or the like, and the equpiment (2) for maintaining the climate is placed in connection with the bottom surface (4). The growth chamber (3) is also provided with horticultural equipment (7), which in the present embodiment comprises both equipment (7a) for plant nourishment and equipment (7b) for plant illumination. According to the invention, the growth chamber (3) is formed into a flowing space (16), wherein the ventilation of the growth chamber (3) is provided by flows (w1, w2) essentially in the longitudinal direction (a) of the flowing space (16).

Description

Method and cultivation unit for plant cultivation

The invention relates to a method for plant cultiva¬ tion, whereby at least one species of plant is cul¬ tivated at a time in a growing apparatus, in a growth chamber, the growth environment being controlled by eguipment for maintaining the indoor climate and substantially forming at least one compartment with an indoor climate, wherein, for making preferably a substantially closed structure, the walls surrounding the said growth chamber comprise a bottom surface, side surfaces and an upper surface, wherein at least the said side surfaces or parts of the same and/or the said upper surface or a part of the same are substantially made of light-permeable material, such as plastic, glass or the like, and wherein the said growth chamber is provided with horticultural eguipment which is preferably formed at least of eguipment for plant nourishment and of equipment for plant illumina¬ tion.

Plant cultivation in a single cultivation room instead of conventional greenhouses is previously known e.g. from the Publication FR-2,345,912. The publication discloses a method for the nourishment of plants in a growth environment with controlled indoor climate. In a lightly constructed and movable cultivation room, the plants are placed on movable bases which are moved in the vertical direction by a conveyor driven on the principle of a paternoster. The nutriment for the plants is provided by a nutritious solution in a pool based in the lower section of the cultivation room, the plants drawing nutriment from below as they pass through the same. The pool presented in the publication comprises two parts, whereby the water and nutriment pumped from the lower part of the pool is precipitated and led to the upper part provided with a control mechanism for the liquid level.

The method for plant cultivation according to the publication is advantageous, because it provides a surface area/volume ratio that is advantageous for cultivation. The growth surface can thus be optimized, particularly to minimize the high energy costs due to Nordic conditions. Also, a homogeneous growth environ- ment with equal conditions for all plants to be cultivated can be achieved by movable structures of the type presented. Furthermore, by structures of this type, the work environment of the cultivating staff can be separated from the growth environment of the plants, whereby it is possible to arrange the horticultural operations on the plants in the cultiva¬ tion room in a manner that is advantageous in respect to both occupational safety and ergonometry.

However, the construction presented above is not ap¬ plicable as such in Nordic conditions because of the pool arrangement applied and the light construction of the cultivation room. Because of high daily tempera¬ ture changes, the pool arrangement according to the publication causes condensation of water on the inner surfaces of the plastic foil which will further, at suitable temperatures, be ice-bound. In this case, the transmittance of external light into the cultiva¬ tion room is prevented, and natural light cannot be utilized in all conditions. Furthermore, the continuous moistening of plastic foils causes soiling of the surfaces, requiring also cleaning measures or change of plastic foils at certain intervals. Moreover, because of the irrigation from below, the lower part of the plants rooted in soil must also be packed in water-permeable material, for which reason the water in the pool is unclean. This aggravates the soiling effect of the condensing water as mentioned above. Because of the pool arrangements used, it is not substantially significant whether plastic foil or a glass casing is used as the outer casing.

Another problem in the practical use of the arrange¬ ments of the type presented or the like, based on the principle of multi-layer or rotational cultivation, as well as in the use of conventional arrangements of cultivation in greenhouses, is, because of the artifi- cial illumination used particularly in the Nordic countries, the ratio between the temperatures of the artificial illumination and the plant. It has been found, particularly in multi-layer cultivation with little heat radiation between the plant and the green- house structures, that the temperature of the plant is maintained at a level higher than normal. This results to the requirement of either choosing the plants to be cultivated from those suitable for the cultivation method used, or reducing the quantity of artificial light, which will slow down growth. A common problem in the cultivation of plants indoors is also the fact, that the temperature of the growth environment often rises even by several degrees in the vertical direction of the greenhouse. Thus, it is not possible to attain homogenous temperature condi¬ tions in the whole cultivation room even by an arrange¬ ment e.g. according to the Publication FR-2,345,912.

Consequently, it is not possible by arrangements known from the prior art to control satisfactorily the conditions of the growth environment so that the efficiency of multi-layer or rotational cultivation could be sufficiently utilized.

It is an aim of the method according to this invention to attain a decisive improvement to the disadvantages presented above and thus to raise the level of prior art in the field. For achieving this aim, the method according to the invention is mainly characterized in that the growth chamber is formed as at least one flow space, such as a flow duct or the like, whereby the ventilation of the growth chamber is achieved in the said flow space or in a part of the same as an air flow substantially in the longitudinal direction of the flow space, whereby the direction of the said air flow or a part of the same is, in the cross-section perpendicular to the longitudinal direction of the flow space, substantially equal at each flow point of the growth chamber limited by the flow space or a part of the same.

The most important advantages of the method according to the invention are simplicity and reliability, whereby the conditions of the growth environment of the plants can be easily controlled and automated. The efficiency of the method is based on the fact that it is possible to compensate the dark and cold seasons particularly in Nordic conditions by stable and homogeneous growth conditions.

Further, in comparison e.g. with ordinary field cultivation of potatoes, the application of the method removes e.g. the risks due to climate. In ordinary field cultivation, the potatoes must usually be placed in the germination phase close to the surface of the ground, even to be partly visible, so that the solar heat radiation effective on them would start the germination phase of the potatoes as effectively as possible, in spite of the low temperature of the ground below. Because of the placement of the potatoes in the surface layer, chlorophyl may accumulate in the developing tubers that are partially visible, whereby they are inedible. By application of the method according to the invention e.g. in the cultiva¬ tion of potatoes, the potatoes can be placed fully inside a layer of soil, in which case the problem mentioned above is avoided.

Advantageous embodiments of the method according to the invention are presented in other dependent claims concerning the method.

The invention relates also to a cultivation unit for application of the method. The cultivation unit is defined more closely in the ingress of the independent claim concerning the cultivation unit. The main characteristics of the cultivation unit are presented in the characteristic part of the corresponding claim.

Using a cultivation unit according to the invention, it is possible in a simple and reliable manner to control the conditions of the growth environment of the plants to be cultivated, whereby also the opera¬ tions related to the growth unit can be easily per- formed and automated as well as arranged in an ad¬ vantageous manner with respect to both occupational safety and ergonometry.

Furthermore, using a cultivation unit according to the invention, it is possible to avoid common problems due to icing up or frosting of window surfaces, whereby natural light has free access to the inside of the cultivation unit when needed.

Advantageous embodiments of the cultivation unit according to the invention are presented in dependent claims on the cultivation unit.

In the following description, the invention is il- lustrated in detail with reference to the appended drawings, in which Fig. 1 shows a cross-sectional view of an embodi¬ ment according to the invention in prin¬ ciple, wherein the growth bases of the cultivation unit are arranged to be movable in the vertical direction,

Fig. 2 shows a perspective view of an embodiment according to the invention in principle, wherein the growth bases of the cultivation unit are arranged to be movable in the horizontal direction,

Fig. 3 shows a perspective view of an embodiment according to the invention in principle, wherein the growth base of the cultivation unit is arranged to be solid,

Fig. 4 shows in principle a perspective view of a greenhouse comprising two cultivation units, and

Fig. 5 shows in principle a perspective view of a greenhouse comprising six cultivation units.

The cultivation unit used for application of the method according to the invention comprises a growing ap¬ paratus 1 placed in a growth chamber 3, wherein the plants to be cultivated are placed on growth bases la which are moved in the vertical direction by transfer equipment lc driven on the principle of a paternoster. Equipment 2 for maintaining the indoor climate of the growth environment is used to achieve controlled growth conditions in the growth chamber 3. The walls surrounding the growth chamber 3 comprise a bottom surface 4, side surfaces 5 and an upper surface 6. The side surfaces 5 and the upper surface 6 are made of a light-permeable structure, such as insulating glazing elements or the like, and the equipment for maintaining the indoor climate is arranged in conjunc¬ tion with the bottom surface 4. The growth chamber 3 is also provided with horticultural equipment 7, which in the presented embodiment comprises both equipment 7a for plant nourishment and equipment 7b for plant illumination. According to the invention, the said growth chamber 3 is formed into a flowing space 16, whereby the ventilation of the growth cham- ber 3 is effected by flows wl, w2 substantially in the longitudinal direction fo the flowing space 16.

The embodiments shown in Figs. 1 to 3 also make use of the principle presented in the Finnish Patent Applica- tion No. 906403 by the applicant, whereby the growth chamber 3 is provided with shading equipment 8 for artificial control of the natural daily rhythm of the plants. In the embodiment shown in Fig. 1, the shading equipment 8 comprises blinds 8a which are movable by an electric motor and by a wire rope 9. In the embodi¬ ment shown in Fig. 2, the shading equipment 8 comprises a solid, horizontally placed shading space 8b con¬ structed of plates. In the embodiment shown in Fig. 3, the shading equipment 8 comprises an accordion-folded plate structure 8c.

In an advantageous embodiment according to the inven¬ tion shown in Fig. 1, there is an air flow w induced at least partially by circulating the air inside the growth chamber 3 by an axial blower 17. The flowing space 16 is formed by dividing the growth chamber 3 in two compartments by a light-permeable partition wall. Thus, there is a primary flow wl from the pressure part of the axial blower 17 in the primary duct 16a and a corresponding secondary flow w2 returning to the suction side of the axial blower 17, the said flows wl, w2 taking directions corresponding to the directions of movement of the growth bases la. The advantageous feature of a solution of this kind is based on the fact that the movement of the growth bases la and flows wl, w2 at least periodically in the same direc¬ tion can be used to minimize the relative difference in speed of the plants and the air flows, whereby the ventilation can be made more effective, when necessary, without causing damage to the plants. Because of the circulation of the air inside the growth chamber 3, it is naturally advantageous to provide the axial blower 17 with a filter 18 or the like.

As shown in Fig. 1, the equipment 2 for maintaining the indoor climate of the growth environment, such as e.g. an electric heater and an air humidifier, and the axial blower 17 with its filter 18 are placed prefer¬ ably below the bottom surface 4. By this arrangement, they do not increase the bottom surface area of the cultivation unit, but insulate the cultivation unit from the ground. Thus it is possible according to an advantageous embodiment to connect the axial blower 17 to operate with the equipment 2 for maintaining the indoor climate in a way that the climate inside the growth chamber 3, such as e.g. the humidity and the temperature, is maintained by the air blow w, by humidifying the air flow w e.g. by an evaporator and heating it e.g. by an electric resistor. In this case, it is naturally possible to arrange also the cooling of the air blow w in a simple way, e.g. for the recovery of heat by conventional heat recovery arrangements by installing e.g. a cooling coil at a suitable place. In the present embodiment, the equip¬ ment 7a used for plant nourishment is preferably arranged to provide nutriment for the plants from above, wherein it is formed e.g. of spraying assemb- ly 7a arranged at one place, as shown in Fig. 1. The nutriment is thus provided in fluid or gaseous form to be sprayed from the spraying assembly 7a. The equipment 7b used for plant illumination is situated in the corresponding direction, at four levels on the centre line of the cultivation unit, whereby all plants can be effectively illuminated as the growth bases la are moved.

For practical embodiments, it is further advantageous to arrange the quality of the air that is circulated to be controllable, whereby the cultivation unit comprises on one hand a fresh air valve 19 and on another hand an outlet valve 20. The quantity of the air in the air flow w can thus be controlled e.g. by limiting the flow through the fresh air valve 19. Thus, when only the air flow w is circulated, it is advantageous to close both valves 19, 20.

As an advantageous alternative in the embodiment presented, the flowing space 16 can also be formed so that the primary flow wl consisting of e.g. four partial flows passes from below upwards in the air ducts placed at the corners of the growth chamber 3, whereby the secondary flow w2 passes, correspondingly, from above downwards as a total flow touching the growing apparatus l. It is thus possible to use the air ducts also as the frame or a part of the support structure of the cultivation unit.

In a preferable embodiment, the ventilation control of the growth chamber 3 of the cultivation unit is arranged to be programmable, whereby, for integrated control of the whole cultivation unit according to the above-mentioned previous patent application by the applicant, it is advantageous to arrange also the horticultural equipment 7, the growing apparatus l, the equipment 2 for maintaining the indoor climate and the shading equipment 8 to function under inte¬ grated control by means of a microcomputer 10. The embodiment shown in Fig. 1 operates in a way that the air flow w coming through the filter 18 leaves the pressure side of the axial blower 17 as the primary flow wl upwards in the primary duct 16a limited by the partition wall 21. Thus the cultivated plants move in a corresponding manner upwards, either periodi¬ cally or continuously, in conjunction with the walls of the growth chamber 3. As the growth bases la move on the folding wheel of the transfer equipment lc, the air flow w makes a turn at the end of the partition wall 21 and passes further downwards as the secondary flow w2 in the secondary duct 16b limited by the partition wall 21, corresponding to the direction of movement of the movable growth bases la. Depending on the quantity of the air circulated, part of the secondary flow w2 is discharged, in the present embodiment through the outlet valve 20 placed in the lower part of the growth chamber 3. The corresponding replacement air is in the present embodiment provided through the fresh air valve 19 placed in the space below the bottom surface 4, whereby the total air flow w is again passed through the filter 18 to the suction side of the axial blower 17 and so on.

In the embodiment shown in Fig. 2, comprising several movable plant growth bases la which are moved in the horizontal direction e.g. by means of an electric motor and a chain-driven drive wheel/folding wheel arrangement lb, the operating principle presented above can be utilized, thanks to the shading space 8 used, in a manner that there is no need to divide the growth chamber 3 by a separate partition wall but the upper wall 8b¹ of the solid shading space 8b functions as the dividing part of the flow space.

In the embodiment shown in Fig. 2, the equipment 2 for maintaining the indoor climate and the axial blower 17 are preferably arranged in connection with the second side surface 5a perpendicular to the longi¬ tudinal direction b of the growing apparatus 1. It is thus possible to achieve a smooth air flow through the growth chamber 3.

In the embodiment shown in Fig. 3, which is intended particularly for the cultivation of plants with long sprouts, such as tomatoes or the like, the growing apparatus 1 comprises a solid growing level la¹ and a movable ceiling Id arranged below the upper surface 6. Thus, the accordion-folded plate structure 8c of the shading equipment 8 used in the present embodiment is an advantageous structure, because the plates 8c can be easily made of a heat-insulating material, whereby they can be used as heat insulators e.g. in seasons when natural light has little significance. For the sake of illustration, the view shown in Fig. 3 is reduced to show the plate structure 8c arranged in connection of two side surfaces 5 only.

The circulation of the air can also in this embodiment be arranged according to the principle presented above, e.g. by arranging a movable partition wall 21a by a rail arrangement or the like in connection with the ceiling.

It is clear that the invention is not limited to the applications presented above but it can be modified within the basic idea even to a great extent. Firstly, the air flow can be arranged as a flow-through only, whereby only external air flows through the growth chamber and exits through the upper surface which can be at least partially opened. Correspondingly, the means for maintaining the flow can be a centrifugal blower or several blowers in a series or in parallel. The primary duct and the secondary duct used for the circulation of air can also be arranged in a number of ways different from those presented above. Also the blower can naturally be placed in connection with the upper surface or e.g. in the space above the same as well. Thus, dust or the like falling from the growth chamber does not cause stoppage of the filter connected to the blower. The blower being placed in connection with the bottom surface, it is naturally advantageous to arrange a riddle or a corresponding sieve to the suction part of the same for separating at least large particles from the air flow before the filter. The growing apparatus and the flowing space can naturally be arranged in different longitudinal directions, for example in a way that the movement of the growth bases in -the growth chamber is vertical and the flows are passed in horizontal flow ducts, or vice versa. The cultivation unit according to the invention can naturally be arranged, according to the Finnish Patent Application Publication No. 906403 by the applicant, into a greenhouse comprising two or more cultivation units, as shown in Figs. 4 and 5, in which the ventilation can preferably be arranged to be effected at least partly by joint control means.

Claims

Claims :

1. Method for plant cultivation, wherein at least one species of plant is cultivated at a time in a growing apparatus (1) in a growth chamber (3) , the growth environment being controlled by equipment (2) for maintaining the indoor climate and substantially forming at least one compartment with an indoor climate, wherein, for making preferably a substantially closed structure, the walls surrounding the said growth chamber (3) comprise a bottom surface (4) , side surfaces (5) and an upper surface (6) , wherein at least the said side surfaces (5) or parts of the same and/or the said upper surface (6) or a part of the same are substantially made of light-permeable material, such as plastic, glass or the like, and wherein the said growth chamber (3) is provided with horticultural equipment (7) which is preferably formed at least of equipment (7a) for plant nourishment and of equipment (7b) for plant illumination, charac¬ terized in that the said growth chamber (3) comprises at least one flowing space (16) , such as a flow duct or the like, wherein the ventilation of the growth chamber (3) is provided by an air flow (w) in the said flowing space (16) or a part of the same, substan¬ tially in the longitudinal direction (a) of the flowing space (16) , wherein the direction of the said air flow (w) or a part of the same is, in a perpendicular cross-section of the longitudinal direction (a) of the flowing space (16) , substantially equal at all flow points in the growth chamber (3) limited by the flowing space (16) or a part of the same.

2. Method according to Claim 1, characterized in that the said air flow (w) is at least partially generated by circulating the air inside the growth chamber (3) by one or several flow generating means (17) , such as a blower or the like, wherein the said flowing space (16) comprises on one hand one or several primary ducts (16a) , in which a primary flow (wl) is generated from the pressure side of the said flow generating means (17) , and on the other hand one or several secondary ducts (16b) , in which a secondary flow (w2) returns to the suction side correspondingly, and that at least a means (18) for purifying the said air flow (w) , such as a filter or the like, is arranged in the said flowing space (16) , preferably in connection with the flow generating means (17) .

3. Method according to Claim 1 and/or 2, charac¬ terized in that the said one or several flow genera- ting means (17) is placed in connection with the said equipment (2) for maintaining the indoor climate in a way that the change and/or maintenance of the indoor climate in the said growth chamber (3) , preferably at least the humidity and/or temperature, is provided by means of the air flow (w) in a manner known as such by humidifying and/or heating and/or cooling the air flow (w) .

4. Method according to one of the Claims 1 to 3 above, wherein the said growing apparatus (1) comprises one or several growth levels (la*) which are at least during the growing phase substantially solid with respect to the growth chamber (3) , and at least in connection with the cultivation of plants with long sprouts, such as tomatoes or the like, a ceiling (Id) which is movable in the vertical direction and placed below the upper surface (6) , such as a plate or the like substantially made of light-permeable material, the sprouts of the cultivated plants being fixed to the same, characterized in that the said at least one flowing space (16) is arranged to be substantially vertical in its longitudinal direction (a) , and that the said one or several flow generating means (17) , such as preferably an axially-driven blower or the like, is placed preferably in connection with the bottom surface (4) and/or the upper surface (6) or the growth chamber (3) .

5. Method according to one of the Claims 1 to 3 above, wherein the said growing apparatus (1) comprises preferably two or more movable plant growth bases (la) which are arranged to be movable substantially in the vertical direction by means of transfer equipment (lc) driven on the principle of a paternoster or the like, characterized in that the said at least one flowing space (16) is arranged to be substantially vertical in its longitudinal direction (a) , and that the said one or several flow generating means (17) , such as preferably an axially driven blower or the like is placed preferably in connection with the bottom surface (4) and/or the upper surface (6) of the growth chamber (3) .

6. Method according to one of the Claims 1 to 3 above, wherein the said growing apparatus (1) com¬ prises preferably two or more movable plant growth bases (la) which are arranged to be movable substan- tially in the horizontal direction by means of a conveyor apparatus (lb) or the like, characterized in that the said at least one flowing space (16) is arranged to be substantially horizontal in its longi¬ tudinal direction, and that the said one or several flow generating means (17) , such as preferably an axially driven blower or the like, is placed in connection with at least one of the two side walls (5a) of the growth chamber (3), preferably in the direc¬ tion (b) perpendicular to the said growth apparatus (1) .

7. Cultivation unit for plant cultivation, wherein at least one species of plant is arranged to be cultivated at a time in a growing apparatus (1) controlled by means of eguipment (2) for maintaining the climate inside the growth environment and forming at least one compartment with an indoor climate, whereby, for making a substantially closed structure, the walls surrounding the said growth chamber (3) comprise a bottom surface (4) , side surfaces (5) and an upper surface (6) , whereby at least the said side surfaces (5) or parts of them and/or the said upper surface (6) and or a part of it are made of a substan¬ tially light-permeable material, such as of plastic, glass or the like, and wherein the said growth cham¬ ber (3) is provided with horticultural equipment (7) comprising preferably at least equipment (7a) for plant nourishment and equipment (7b) for plant il¬ lumination, characterized in that the said growth chamber (3) is arranged to form at least one flowing space (16) , such as a flow duct or the like, wherein the ventilation of the growth chamber (3) is provided by an air flow (w) in the said flowing space (16) or a part of the same, substantially in the longitudinal direction (a) of the flowing space (16) , wherein the direction of the said air flow (16) or a part of the same is in a perpendicular cross-section of the longitudinal direction (a) of the flowing space (16) substantially equal at all flow points in the growth chamber (3) limited by the flowing space (16) or a part of the same.

8. Cultivation unit according to Claim 7, charac¬ terized in that the said air flow (w) is generated at least partially by circulating the air inside the growth chamber (3) by one or several flow generating means (17) , such as a blower or the like, wherein the said flowing space (16) comprises on one hand one or several primary ducts (16a) , in which a primary flow (wl) is generated from the pressure side of the said flow generating means (17) , and on the other hand one or several secondary ducts (16b) , in which a secondary flow (w2) returns to the suction side correspondingly, and that at least a means (18) for purifying the said air flow (w) , such as a filter or the like, is arranged in the said flowing space (16) , preferably in connection with the flow generating means (17) .

9. Cultivation unit according to Claim 7 and/or 8, characterized in that the said one or several flow generating means (17) is arranged in connection with the said equipment (2) for maintaining the climate in a way that the change and/or maintenance of the indoor climate in the said growth chamber (3) , preferably at least the humidity and/or temperature, is provided by means of the air flow (w) in a manner known as such by humidifying the air flow (w) by an evaporator or the like and/or heating it by an electric resistor or the like and/or cooling it with a cooling coil or the like.

10. Cultivation unit according to one of the Claims 7 to 9 above, wherein the said growing apparatus (1) is formed of one or several growing levels (la¹) which are at least during the growing phase substantially solid with respect to the growth chamber (3) , and at least in connection with the cultivation of plants with long sprouts, such as tomatoes or the like, a ceiling (Id) which is movable in the vertical direction and placed below the upper surface (6), such as a plate or the like made of substantially light-permeable material, the sprouts of the cultivated plants being fixed to the same, characterized in that the said at least one flowing space (16) is arranged to be substantially vertical in its longitudinal direc¬ tion (a) , and that the said one or several flow generating means (17) , such as preferably an axially- driven blower or the like, is placed preferably in connection with the bottom surface (4) and/or the upper surface (6) or the growth chamber (3) .

11. Cultivation unit according to one of the Claims 7 to 9 above, wherein the said growing apparatus (1) comprises preferably two or more movable plant growth bases (la) which are arranged to be movable substan¬ tially in the vertical direction by means of transfer equipment (lc) driven on the principle of a paternoster or the like, such as an electric motor or the like and a power transmission assembly driven by a chain, cone belt or the like, characterized in that the said at least one flowing space (16) is arranged to be substantially vertical in its longitudinal direc- tion (a) , and that the said one or several flow generating means (15) , such as preferably an axially driven blower or the like is placed preferably in connection with the bottom surface (4) and/or the upper surface (6) of the growth chamber (3) .

12. Cultivation unit according to one of the Claims 7 to 9 above, wherein the said growing apparatus (1) comprises preferably two or more movable plant growth bases (la) which are arranged to be movable substan- tially in the horizontal direction by means of a conveyor apparatus (lb) or the like, such as an electric motor or the like and a power transmission assembly driven by a chain, cone belt or the like, characterized in that the said at least one flowing space (16) is arranged to be substantially horizontal in its longitudinal direction, and that the said one or several flow generating means (15) , such as prefer¬ ably an axially driven blower or the like, is placed in connection with at least one of the two side walls (5a) of the growth chamber (3) , preferably in the direction (b) perpendicular to the said growth appara¬ tus (1) .

13. Cultivation unit according to Claim 10, 11 or 12, characterized in that at least one primary duct (16a) or secondary duct (16b) of the said flowing space (16) is formed in the air space of the growth chamber (3) surrounding the growing apparatus (l) and, correspondingly, one or several secondary ducts (16b) or primary ducts (16a) are formed in an air space with a climate separate from that of the growing apparatus (1) by means of an air duct or the like.

14. Cultivation unit according to Claim 13, characterized in that the air space with a climate separate from that of the growing apparatus (1) is arranged by air ducts or the like placed in at least one, preferably all corners of the growth chamber (3) , wherein the said air ducts or the like form preferably at least part of the frame forming the support struc¬ ture of the cultivation unit.

15. Cultivation unit according to Claim 10, 11, 12, characterized in that one primary duct (16a) and one secondary duct (16b) of the said flowing space (16) are formed by dividing the said growth chamber (3) into two compartments, preferably by a partition wall (21) or the like made of light-permeable material, wherein the said primary flow (wl) and secondary flow (w2) in the said primary duct (16a) and secondary duct (16b) pass substantially in the directions corresponding to the respective directions of movement of the growth bases (la) .

16. Cultivation unit according to one of the Claims 7 to 15 above, characterized in that the quantity of the air circulated in the said air flow (w) can be controlled, wherein the cultivation unit comprises on one hand an external air inlet (19) , such as a fresh air valve or the like, and on the other hand an outlet (20) for exhaust air from the growth cham¬ ber (3) , such as an outlet valve or the like, wherein the quantity of the indoor air can be controlled preferably by limiting the flow through the said inlet (19) and/or the said outlet (20) or by cor¬ responding means.