FI103009B - Plant cultivation procedure - Google Patents

Description

103009

Plant cultivation method

The invention relates to a method of cultivating plants in which the water evaporated by the plants is recycled for re-use by the plants.

5 During the growing season, the amount of water evaporated during plant growing can be up to two hundred times the yield of the plants. If water is difficult to obtain and prices are high, this makes it impossible to grow crops economically. The amount of water needed for irrigation is reduced if the water is led through the underground pipeline network to the roots of the plants so that losses due to direct evaporation of the water are avoided. However, water is still needed at least 100 times the crop weight.

A significant reduction in the need for irrigation water is thus achieved only by re-using evaporated water. This requires cultivation in a greenhouse or similar environmentally enclosed space. The difficulty here is to accumulate solar energy into the greenhouse air, which at a temperature of 70-80 ° C would destroy the crop. In addition, the condensation of evaporated water to irrigation water would require expensive-use refrigerators.

DE-A-1 632 908 discloses a greenhouse which can be recycled: humid indoor air is returned to the substrate. However, the system shown is not water; It is closed with respect to the air and air circulation, but mixes with the recirculated air; .. 'the incoming air, whereby the excess air is discharged from the open air outlet. The greenhouse is irrigated by irrigation water piping and, in addition, according to the publication, water can be added to the recirculated air.

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Contrary to the above, the present invention provides for plant cultivation with respect to irrigation water and air circulation in a completely closed system. The process according to the invention is characterized in that the plants are grown in an environmentally friendly environment. • waterproofed enclosed space where plants are irrigated • · · *. by removing moisture from the plants to the substrate.

., ..: The cultivation according to the invention is preferably carried out in a closed greenhouse, in which 30 damp air is supplied to the substrate by means of a fan. Along with humidity, 'the flow transfers the heat energy from the sun to the substrate. Substrate: "· Underneath the growth layer there may be a coarse gravel layer where the recirculated air is blown so that it spreads below the growth layer and is distributed as evenly as possible over the 2 103009 growth layer. The denser and cooler cooled in the greenhouse airspace.

The growth layer of the substrate may consist of a soil layer mixed with ha-5 intoxicating organic waste. Waste decomposing during the growing season can thus satisfy the plant's need for carbon dioxide in a closed system.

Carbon dioxide from waste is utilized by the plants in photosynthesis, which releases oxygen, which in the air circulates back into the growth layer to oxidize the waste. The system thus has favorable conditions for the rapid decomposition of waste. When the leaves and stems of the previous crop are used as composting waste, the growth layer only needs to add decomposing material in the amount corresponding to the new crop to be produced. In the system, the carbon content is easily considered to be several times higher than the ambient carbon content, resulting in an increase in growth rate. In addition, the closed system protects the crop against external plant diseases, pests and weeds.

In the system according to the invention, the increase in the temperature of the greenhouse air space due to sunlight can be prevented by controlling the air circulation. The principle here is to circulate the air 24 hours a day so that during the daytime the heat energy is transferred to a substrate with sufficient heat capacity and at night time the airflow cools the substrate by transferring the heat energy back into the greenhouse air space.

The confined culture of the invention requires only a single watering of the substrate at the beginning of the growing season. After that, cultivation takes place without the addition of irrigation water. Only the amount of water that is included in the harvest yield is removed from the farm.

An example of a greenhouse operating in accordance with the invention is shown in the accompanying figure 1. The figure shows a space 2 isolated from its surroundings, the upper part of which is bounded by a structure 3 of material permeable to solar radiation such as plastic or glass. 30 air spaces 2 in the substrate to the lower gravel layer 6. The air spreads evenly to the gravel layer 6 and rises from it to the top soil layer 7, which after it passes, returns to the air space 2. The soil layer 7 is mixed with compostable plant material to produce carbon dioxide for plants.

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The greenhouse of Fig. 1 allows cultivation of the invention in an airtight, confined space without the addition or removal of water or substrate carbon dioxide producing material during the growing season. Leaves and stems of the previous crop are left in growth layer 7 for composting. At the beginning of cultivation 5, 10-20 mm basic watering is carried out, which is sufficient for the entire growing season. During the growing season, the greenhouse is maintained without recirculation, in which the moisture evaporated from the plants into the air space 2 returns to the substrate, in which it condenses into water for irrigating the plants. In addition, the circulating air circulates heat from the airspace 2 to the cooler layer 7 during the day and back to the airspace 2 with the cooler airflow from the layer 10 at night. Similarly, during the night time, heat energy radiates out into a colder environment.

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Claims (8)

4, 103009 A method for cultivating plants, characterized in that the plants are grown in a water-tight enclosure (2) enclosed in their environment, in which the plants are irrigated by recirculating the moisture evaporated from the plants with the air back to the substrate (7). Method according to Claim 1, characterized in that the air is circulated by means of a fan (4). Method according to Claim 1 or 2, characterized in that the air recirculation flow is conducted under a growth layer (7) belonging to the substrate, from which the air rises upwards to the growth layer, in which part of the moisture in the air condenses. Method according to Claim 3, characterized in that the air recirculation flow is directed to the gravel layer (6), from where it rises to the higher denser growth layer (7) and after it has passed through the upper air space (2). Method according to one of the preceding claims, characterized in that the carbon dioxide required by the plants is produced from the decomposing plant material in the growth layer (7). Method according to one of the preceding claims, characterized in that the above-ground part (2) of the rearing space is delimited by a structure (3) of material permeable to solar radiation, such as plastic or glass. The method according to claim 6, characterized in that the air is circulated around the clock so that during the daytime the heat energy is transferred to the growth medium (7) and at night it is removed. A method according to any one of the preceding claims, characterized in that, after a single irrigation at the beginning of the cultivation, the cultivation is carried out without the addition of irrigation water and that only the amount of water contained in the yield yielding high · · * · 1 leaves the cultivation space. j 103009