RU2281647C2 - Method for hydroponic growing of c3 plants - Google Patents

Abstract

FIELD: agriculture, in particular, growing of plants in protected ground, for example in greenhouses, on neutral substrate with feeding of plants with macro- and micro elements supplied to zone under roots and feeding with carbon dioxide.

SUBSTANCE: method involves growing C₃ plants in greenhouses on substrates by feeding nutritive solution under plant roots, feeding of plants with carbon dioxide and also by providing illumination with the use of lamps; hermetically covering plants with transparent film laid over constructions which may be adjusted in vertical plane as plants grow. Carbon dioxide is automatically supplied to zone under film by means of programmer. Nutritive solution is supplied into substrate in accordance with signal generated by moisture content sensor.

EFFECT: reduced consumption of carbon dioxide supplied for feeding of plants, decreased capital and operation costs, reduced consumption of power for heating greenhouses, and increased yield of plants.

2 cl, 1 dwg, 1 tbl

Description

The invention relates to the field of agriculture, in particular to methods of growing plants in sheltered soil, for example in greenhouses, on a neutral substrate with root nutrition of plants macro- and microelements and feeding them carbon dioxide.

It is known that fertilizing plants in greenhouses with carbon dioxide can significantly increase crop yields. For this fertilizing plants produce CO ₂ by feeding the plants into the surrounding atmosphere fog, saturated with carbon dioxide [1] or in the environment burn paraffinic hydrocarbon is naphthalene [2], or in a greenhouse supplied carbon dioxide generated in the fermentation installation [3].

Such methods require the manufacture and installation of special plants that burn fuel or use a nutrient medium for yeast culture. At the same time, pipelines are needed to supply carbon dioxide to the greenhouses. To obtain an increased concentration of CO ₂ in the air of greenhouses using these methods, a large amount of gas must be supplied. In addition, the greenhouses are leaky and there is a leak of carbon dioxide into the atmosphere, which affects the environment.

It is also known that in the industrial cultivation of plants, carbon dioxide is supplied in large quantities to the volume of the entire greenhouse. In this case, it is obtained by burning fuel in special gas generating units (prototype) [4].

However, gas pipelines are required to supply carbon dioxide to the greenhouses. Installation and operation of such installations is expensive. In addition, the resulting gas must be cleaned of related impurities.

The aim of the invention is to reduce the consumption of the total amount of carbon dioxide supplied to the greenhouse to feed plants, reduce costs and increase productivity.

The goal is achieved by a method of hydroponic cultivation -rasteny C ₃ comprising feeding the nutrient solution by the roots of plants, feeding of carbon dioxide and artificial illumination, plants hermetically coated film, the composition of the nutrient solution is adjusted in accordance with the feed rate of the film under CO _2, And artificial illumination is created by light sources located at the minimum permissible height above the film.

This method makes it cost-effective to use high-quality bottled gas, since the supply of CO ₂ under the film from the balloon reduces the consumption of the total amount of carbon dioxide supplied to the greenhouse. At the same time, there is no need to build gas generating stations and lay gas pipelines. And then feeding with carbon dioxide becomes available even in small greenhouses, it turns out to be mobile, flexible and selective (that is, it can be applied as needed).

Supply amount of CO ₂ as plant growth increased automatically using a temporary programming of the program that is determined empirically for each plant species using the flowmeter and the analyzer CO ₂ (according to the developed technique). And in order to increase the light intensity from electric lamps, they are lowered over the film to the minimum allowable distance, i.e. so that the film does not melt from the emitted radiation. This allows you to create a higher illumination, sufficient for growing most crops, without additional light sources. At the same time, this makes it possible to raise the temperature under the film (due to radiation and the greenhouse effect) to the level necessary for growing plants under conditions when the temperature in the greenhouse is already insufficient for this. In this case, the optimization of plant nutrition is especially significant, since only with optimal nutrition, corresponding to the ability of their photosynthetic apparatus to absorb CO ₂ at this stage of growth, the largest increase in yield can be obtained. Under the film, with increasing temperature, the air humidity also increases. However, in this case, the moisture on the leaves does not condense, but condenses on the film, and flows back into the tray with the substrate, which leads to water saving. At the same time, an increase in air humidity also contributes to the opening of leaf stomata, which, in turn, enhances the absorption of carbon dioxide during photosynthesis and increases yield.

The claimed invention is characterized by the following essential features that distinguish it from the prototype:

- cover plants hermetically with a film;

- adjust the composition of the nutrient solution in accordance with the flow rate supplied automatically under the film of carbon dioxide;

- create artificial illumination by light sources located at the minimum allowable height above the film.

Since no analogue has been identified, characterized by features identical to the essential features of the claimed invention noted above, the latter can be recognized as meeting the requirement of novelty.

The claimed invention corresponds to the inventive step, since the developed method does not follow for a specialist explicitly from the prior art.

The identified set of essential features of the claimed invention ensures the achievement of a technical result, which consists in reducing the unproductive consumption of CO ₂ necessary for the effective feeding of plants, reducing operating costs and increasing productivity.

The proposed method is intended for use in agriculture and allows relatively cheap to obtain high crop yields in conditions of poorly heated (and not even heated) greenhouses in the autumn-winter period.

Information confirming the possibility of carrying out the invention

The proposed method (in experimental design) was tested when growing lettuce plants for two autumn-winter seasons (1999-2001) in the greenhouse of the VIR Pushkin laboratories, the temperature of which was maintained in the cold season only to maintain its heating, glazing and racking equipment, and did not exceed 10 ° С at this time of the year, i.e. temperature at which agricultural plants hardly grow.

On the rack 1 of the greenhouse, a shallow tray 2 was installed strictly horizontally, on which plastic bags 3 were placed, filled with an inert substrate 4 (drawing). Over the pallet 2, supporting structures 5 were installed (for the film 12), the height of which above the bags can be adjusted. Gas was supplied from bags 6 with high pressure carbon dioxide through a reduction gear 7 and solenoid valve 8 to bags 3 through rubber tubes 9. In places of gas supply, electric fans 10 were fixed for mixing CO ₂ with air. After wetting the substrate 4 in the slot on the bags 3, a two-week-old salad seedlings of the 11th grade of the Ballet were planted. Lettuce was chosen for the experiment as a precocious crop, although the method is applicable for growing other C ₃ plants. After this, structures 5 were lowered over the plants 11 to a minimum height and covered with a transparent plastic film 12 (as tight as possible).

Subsequently, the substrate 4 was moistened by automatically feeding the plant roots of the nutrient solution 13 from the tank 14 through the filter 19 by opening the electrovalve 20 according to the signals from the measuring and compensation elements of the moisture sensor 21 of the substrate connected through the connectors 23 and the level sensor of the nutrient solution 22 in the pan 2 Mixing of the nutrient solution 13 in this case was carried out by feeding air to the tank 14 from a small compressor 15, which is more technologically advanced and also allowed aerating the solution 13 before feeding it to the roots of plants 11. A more convenient and reliable level gauge 16 of solution 13 in tank 14 was also used.

To illuminate the plants above the film, electric lamps of the 17th type DRL-400 F were suspended at the minimum permissible height (from the calculation, one lamp per 1 m ^{2 of} illuminated area). This made it possible to create under the film 12 an illumination of about 10 klx, sufficient for the normal growth of most greenhouse crops. Lamps 17 were switched on automatically in the daytime for 12 hours (i.e., a short 12-hour photoperiod was given in order to exclude salad stalking).

At this time, the programmer in the control unit 18, the program of which was predefined for this kind of salad (using a flow meter and an optical-acoustic gas analyzer), maintained the optimum concentration of carbon dioxide under the film by periodically (according to the program) opening of the gas solenoid valve 8. At the same time, taking into account the amount of gas supplied under the film 12, the composition of the nutrient solution 13 was calculated and supplied, which ensures optimal nutrition of the plants 11, which is necessary for the effective operation of their photosynthetics eskogo apparatus. The supply of gas 6 under the film 12 led to a sharp decrease in its consumption. This made it possible to use the more expensive, high-quality balloon gas 6 for feeding plants, as well as increase its concentration under the film 12 without increasing the cost of gas. At the same time, the gasification system was greatly simplified. And at a high concentration of CO ₂ (already at 700 ppm) the greenhouse effect manifested itself, which additionally accumulated radiation energy from the backlight 17 under the film 12, which made it possible to use it as the main heat source to maintain temperatures sufficient for normal growth and development of plants in the autumn-winter period in a poorly heated greenhouse.

The experimental data are shown in the table, from which it can be seen that at all sampling dates, plants of experimental version 1 had a significantly larger number of leaves and a larger biomass (2–2.5 times) compared to control version 2. The growth of raw biomass of a single plant lettuce was 2-2.5 times more intense in the experimental version (9.42-10.63 g / day) compared with the control (3.95-5.52 g / day). The productivity of the Ballet salad in one month reached 6 kg / m ² , which far exceeds the known indicators obtained in industrial greenhouses [4].

Table The productivity of a variety of ballet lettuce obtained in an experimental setup of a hydroponic method of growing C ₃ plants Option 1 Option 2 Sampling Date The number of leaves per plant, pcs. Raw plant biomass, g The number of leaves per plant, pcs. Raw plant biomass, g 13.02 13.3 ± 0.52 66.39 ± 5.29 8.7 ± 0.33 26.34 ± 2.98 02.20 18.5 ± 0.62 140.83 ± 14.10 11.7 ± 0.54 61.10 ± 7.61 02.27 24.7 ± 1.15 206.73 ± 20.97 14.1 ± 0.66 81.67 ± 1.34 5.03 26.3 ± 0.94 254.75 ± 13.86 15.7 ± 0.30 136.79 ± 1.58 Note. Option 1 - increased concentration of CO ₂ in the air (under the film); option 2 - natural concentration of CO ₂ (without coating the plants with a film).

Thus, the proposed technology allows to obtain high yields of high-quality agricultural products in the winter season without additional energy costs and minimal heat consumption.

These data convincingly show the effectiveness of the proposed method of growing plants.

In addition, through the use of certain technical means (installation of more efficient luminaires, light reflectors, and electric fan heaters, which turn on when the temperature under the film decreases to a critical value), in some climatic zones, such cultivation of agricultural plants can be cost-effective in winter and in unheated greenhouses .

Information sources

1. Auth. St. 413914, class A 01 G 7/02, 1974, BI5.

2. Japan patent c. A 01 G 7/02, 9/24, 1995, ISM No. 8.

3. US patent 4003160, A 01 G 31/02, 1977.

4. E.A. Aliev, N.A. Smirnov. The technology of cultivation of vegetables and mushrooms in greenhouses. M .: Agropromizdat, 1987, p. 64-66.

Claims (1)

The method of hydroponic cultivation of C ₃ plants in greenhouses on substrates with the supply of a nutrient solution under the roots of the plants, feeding them with carbon dioxide and backlighting, characterized in that the plants are hermetically covered with a transparent film according to the designs, adjustable in height as the plants grow, and carbon dioxide fed under the film automatically using the programmer, while the nutrient solution is fed into the substrate by the signal of the humidity sensor.