JPS61100131A - Plant growing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a method for growing plants in an artificially created environment, and in particular to light and CO2 concentration.

[Conventional technology]

New plant growing methods and systems are being devised to promote plant growth and produce plants industrially by controlling plant growing environmental conditions.

In general, plants use water and OO2 as their base in their leaves, and when light energy is added, they produce organic matter (photosynthesis), some of which is consumed as energy for maintaining the individual, and the remainder is used to produce organs such as leaves and roots. It is distributed and accumulated, and each organ becomes longer and longer. In such plants, light, CO
It is possible to significantly promote their growth by controlling environmental conditions such as concentration and temperature, resulting in a dramatic increase in land productivity and the possibility of factory production of plants. It's now possible.

In this case, it would be possible to save energy by using sunlight as a light source, but the amount of light fluctuates due to seasonal weather changes, and environmental conditions such as temperature and humidity change accordingly. The reactions of the plants below are complex, making it difficult to plan year-round production of the plants. In addition, huge air conditioning costs were required to create certain environmental conditions, which was ultimately uneconomical. Therefore, with the aim of year-round production planning, artificial Efforts have been made to use light sources to promote the growth and length of plants. In this case, there is an advantage that other environmental factors can be easily controlled to constant conditions, but there is a problem that the lighting power is enormous and it is not economical.

One way to solve these problems is to
By simultaneously irradiating the plant body from the circumferential direction with light having a lower illuminance than the saturation illuminance when light is irradiated only from above the plant body, and by maintaining the CO2 concentration higher than the atmospheric concentration, A plant growing method has been proposed that can promote the growth of the above-mentioned plants at extremely low illuminance.

This method will be explained in more detail below using figures. FIG. 1 is a block diagram showing a plant growing apparatus used in an experiment to demonstrate this method. In the figure, (1O1) is the outer cylinder of a cylindrical plant growth chamber with reeds, the inner circumference is made of reflective material (1O2) such as HL, and an artificial light source (1OS) is installed along the reflective material (1O2). has been done. (104) is an inner cylinder made of glass, and together with the outer cylinder (101), two
It consists of a heavy cylindrical plant growth chamber. The plant body has an inner cylinder (
104) Cultivation pot fixedly installed inside (1o5)
It is planted in the field and grows by being irradiated with an artificial light source (103). At this time, the plant body is irradiated with light from the circumferential direction, and the cylinder (10
4) It was confirmed that uniform illuminance could be obtained in all directions and locations. Heat dissipation from the artificial light source (1OS) is removed by cold air from the cooler (106). In addition, the air guided into the inner cylinder (104) is connected to an air conditioner (2OX).
The cylinder (
11o4) is introduced from the lower part, discharged from the upper part, and returned to the air conditioner (201) by the proa (1), thereby circulating. CO2 is 002 generator, e.g. 002
CO is pumped in the middle of the circulation passage by a cylinder (not shown), 0'' is injected from the inlet (2), and the circulation passage is provided with a fresh air intake (3) and an outlet (4). At this time, the 0 in the circulating air is renewed.
0. CO2 is supplied to keep the concentration at a predetermined value, and C
The 02 concentration is adjusted by the C02 supply amount.

The air conditioner (ZOl) is a device i (201) consisting of a cooler (202), a water spray part equipped with a spray nozzle (203) and a filled tfA layer (204), and a heater (205). The injected air is transferred to a cold prine (
After being cooled by the cooler (202) using the heater (206), the water in the storage tank (ZO+7) is sent to the spray nozzle (203) by the pump (5), humidified by the packed bed (204), and then sent to the heater ( 205) and adjusted to a predetermined temperature and humidity. On the other hand, (301) is filled with a nutrient salt solution of a predetermined concentration, kept at a predetermined temperature by a liquid constant temperature bath (302), and placed in a cultivation pot (105) by a pump (6).

The nutrient salt solution (301) is aerated by the air pump (7), which returns the solution to the tank (303), and a sufficient amount of dissolved oxygen is maintained.

Using the above-mentioned plant growing device, we varied the illumination intensity from 3 Klux to 15 Klux using salad greens as an example, and investigated the relationship between the weight (1) and the number of growing days (0).The results are shown in Figure 2. , C02 concentration is 1200ppm, temperature is 20℃, liquid temperature of nutrient solution (301) is 21℃, relative humidity is 80%, wind speed is 0.5rrV/aeC1 nutrient concentration is 1.2 mm, pH 5-6.5 , the photoperiod was 24 hours.

Further, a fluorescent lamp and an incandescent lamp were used as an artificial light source (:LO3). As is clear from this figure, the growth rate at each illuminance from 3Klu+c to 15/ux (relationship between weight of salad greens and number of growing days) is contrary to conventionally predicted results.
It was found that the salad greens grew to about 20 times the weight in 10 days, with no difference observed. As a result, with this method, the distortion is reduced to 3, which is about 1/7 of the light saturation illuminance (20Klux) when light is irradiated from above! ! υX
It was discovered that plant growth could be promoted in the same way as in the past even at such low illumination levels, solving the economic problem that was the biggest problem in factory plant production, and making it possible to produce plants year-round in a planned manner. An extremely large effect has been obtained.

(Problems to be Solved by the Invention) However, in the above conventional method, light is irradiated only from above the plant, and light with an illuminance lower than the light saturation illuminance in the case of fc is simultaneously irradiated from the circumferential direction of the plant. Because I am doing
Although the growth rate of the above-mentioned plants remains the same, there is a problem that the moisture content increases and the dry matter production decreases.
This figure shows the relationship between illuminance and water content at m.

From this table, it can be seen that the moisture content increases as the illuminance decreases. This invention was made to solve the above-mentioned problems. [Means for Solving the 0L Problem] A method for growing plants according to the present invention aims to prevent the accompanying increase in water content and to provide a method for growing plants with low water content under low illuminance. , simultaneous irradiation of light from the circumferential direction of the plant body with an illuminance that is p number KIUX higher than the light compensation point when light is irradiated only from above the plant body,
The CO2 concentration is made higher than the Co2 concentration corresponding to photosynthetic saturation when light is irradiated only from above.

(Effect) The irradiation of light from the circumferential direction in this invention can promote the growth of the plant at a lower illuminance than when the source is irradiated only from above, and the Co2 concentration can be reduced by irradiating the source only from above. By increasing the Co and A degrees, which corresponds to photosynthetic saturation in the case, it becomes possible to grow plants with low water content even at low illuminance.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. This invention is based on a plant growing method in which low-intensity light is irradiated simultaneously from the circumferential direction.
This was obtained as a result of a detailed study of the influence of 02 concentration. In other words, the effect of C02 fertilization is most pronounced at the light compensation point (the illuminance at which the photosynthetic rate and the respiration rate are equal, as shown in Figure 3), which is determined by the type of plant, and is roughly determined by the type of plant. It was common knowledge that the light saturation point is near the light saturation point, which is higher than the light compensation point (approximately 3 to 3 Klux), but the inventors have found that even with weak light (approximately 3 to 3 Klux), which is several Klux higher than the optical compensation point, If irradiation is carried out simultaneously from the circumferential direction, the effect of oo2 fertilization will be fully demonstrated, and as a result,
It was found that the water content decreased. Moreover, this decrease in moisture content is caused by the conventional fertilization using C only from above.
It has been revealed that it can be seen even at concentrations far exceeding 02 concentration.

In this way, we discovered that when combined with a growth method in which low-intensity light is irradiated simultaneously from the circumferential direction of the plant body, the conditions under which the 002 fertilization effect is fully exerted are different from conventional ones, leading to this invention. DETAILED DESCRIPTION The apparatus used to carry out the method according to one embodiment of the invention is the same as the conventional apparatus shown in FIG. The growth method is omitted because the only difference is the Co2 concentration.

Two new facts were discovered through this experiment. That is, the first is that growth can be significantly promoted by simultaneously irradiating weak light of several KIIJX from the circumferential direction of the plant and raising the CO concentration above the atmospheric concentration.

The illuminance was changed from 5Klux to 15Klux, and the growth rate of salad vegetables (increase in fresh weight per day) and illuminance (K10X
) was investigated using the CO2 concentration (ppm) as a parameter. FIG. 3 shows these results, and also shows the results for upward illumination. As is clear from the figure, the optical compensation point (about 2 Klux in this example) is several K1. ．． At a low illuminance of 51'ux, the effect of applying OO3 cannot be seen with normal irradiation only from above, but if the plant is simultaneously irradiated with light from the circumferential direction, the effect of applying Co2 can be fully demonstrated. I discovered that.

This is due to the fact that with normal irradiation only from above, the amount of light irradiated to the plant is small at low illuminance several KIIIX higher than the light compensation point, and the growth rate is limited by the amount of light.
2 concentration dependence becomes smaller. On the other hand, if irradiation is performed simultaneously from the circumferential direction, the illumination intensity is low and the amount of light irradiated onto the plant body is large.) This is thought to be due to the fact that the growth rate is in turn determined by the Cog concentration. Furthermore, when nine lights are irradiated simultaneously from the circumferential direction, the growth rate is limited in areas with high illuminance, which is thought to be due to the rate-limiting effect of the dark reaction of photosynthesis (a series of reactions in which starch and other substances are assimilated). As mentioned above,
By simultaneously irradiating the plant body with light from the circumferential direction, growth can be promoted at low energy densities in the same way as at high energy densities.

Second, in the above-mentioned growth method in which low-intensity light is irradiated simultaneously from local directions, increasing the CO2 concentration several times higher than the concentration normally applied can prevent an increase in moisture content and a decrease in dry matter production. It is. This will be explained in detail below. Figure 4 shows the effect of CO2 concentration on the increase in live weight (including water) and dry weight when lettuce is grown by irradiating the lettuce only from above, which is based on the literature (Manju Yabuki).

19a5: Agricultural Meteorology 20: 1z5-129). As is clear from this figure, when the particle is irradiated only from above, the CO2 concentration is generally 15°C.
At or above 0 ppm (generally considered to be the CO2 concentration corresponding to photosynthetic saturation), the dry weight hardly increases, but the living weight gradually increases and the water content of the plant increases. Table 2 shows the experimental results according to one embodiment of the present invention. In the experiment shown in FIG. 3 above, the plant body (this The example shows the relationship between the water content (salad greens) and C02f11 degrees (ppm).

As is clear from this table and Figure 3, for example, 5Kl
When low-intensity light called UX is simultaneously irradiated from the circumferential direction of the plant body, the CO2 concentration (in this example, 350.1200 ppm) is lower than the CO2 concentration (for example, 1500 ppm) that corresponds to photosynthetic saturation when light is irradiated only from above. )
and high OOs+ a once (4000ppm in this example)
), it can be seen that the growth rate is higher when a higher CO2 concentration is used, and that the moisture content of 12 also decreases, that is, the dry weight increases.゛As mentioned above, it is possible to simultaneously irradiate the plant from the circumferential direction with weak light (3 to 7 Ktux), which is several KbX higher than the light compensation point (1 to 3 K/LI!) when light is irradiated only from above. For example, the effects of CO2 application can be fully exhibited, growth can be promoted rather than reduced, and an increase in water content can be prevented.

In the above example, the case of salad vegetables was mainly explained, but other leafy vegetables may also be used1.The effective illuminance differs depending on the plant when irradiated at the same time from the light compensation point or from the direction of the horse, so these should be taken into consideration. As a result, several Klu from the optical compensation point
It seems that it is sufficient to simultaneously irradiate high x light from the local direction.

In addition, the ao2 concentration, which corresponds to photosynthetic saturation when irradiated with light only from above, varies depending on the type of plant and the illuminance of the irradiated light, and is 1500 pp as described in the above example.
m is just an example.

Moreover, although the plant growth chambers (1o1) and (1o4) are shown as having a cylindrical shape as an apparatus for carrying out an embodiment of the present invention, the same results will be obtained even if the plant growth chambers (1o1) and (1o4) are spherical or rectangular.

Further, although an artificial light source (XOS) was used as a light source, sunlight may also be used.

Further, in the present invention, the circumferential direction originally means all directions of the plant body, front, back, left, right, and top and bottom, but light may be irradiated from at least the front, back, left, right, and above.

〔Effect of the invention〕

As described above, according to the present invention, light is irradiated only from above the yuzu object, and light with an illuminance several Ktux higher than the light compensation point in the fc case is simultaneously irradiated from the local direction of the other objects, and the CO2 concentration is is higher than the CO2 concentration corresponding to photosynthetic saturation when light is irradiated only from above, which has the effect of promoting plant growth at low illuminance and preventing an increase in water content.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing the FC plant growing apparatus used in experiments to implement the conventional method and the method according to an embodiment of the present invention, and Fig. 2 shows the weight and growing days of salad greens when light is simultaneously irradiated from the circumferential direction. Figure 3 is a characteristic diagram showing the relationship between the growth rate of salad vegetables and illuminance for cases where light is irradiated only from above and simultaneously from the circumferential direction, using aOa concentration as a parameter. , FIG. 4 is a characteristic diagram showing the relationship between the live weight and dry weight of lettuce and Co and concentration when light is irradiated only from above. In the figure, (101) is the outer cylinder of the double cylindrical plant growth chamber, (102) is the reflective material, (1OS) is the artificial light source, (10
4) is a cylinder, (xo5) is a cultivation pot, (zox) is an air conditioner, (301) is a nutrient solution, (2) is 00. Pour into the inlet. 1 person Bao Ohmaki Figure 3 Figure 4 CO2 concentration (pp-)

Claims (1)

[Claims] In a plant growing method that promotes plant growth by controlling at least light and CO_2 concentration among environmental conditions, the temperature is several kiloliters below the light compensation point when light is irradiated only from above the plant body.
A method for growing a plant, characterized by simultaneously irradiating light with a high _u_x intensity from the circumferential direction of the plant body, and raising the CO_2 concentration higher than the CO_2 concentration corresponding to photosynthetic saturation when light is irradiated only from above. .