JP2016116484A - Cultivation method using solid culture medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of watering plants by a watering amount preferable for the growth of plants, as a cultivation method of plants using solid culture medium.SOLUTION: A cultivation method of plants using solid culture medium which restricts a root zone includes: (a) a process of setting a watering amount per solar radiation amount; (b) a process of setting an upper limit value and a lower limit value of soil moisture content of the solid culture medium; (c) a process of measuring soil moisture content of the culture medium, comparing the soil moisture content with the set upper limit value and lower limit value, and adjusting the watering amount; and (d) a process of giving water of a watering amount per solar radiation amount which is adjusted by the process (c) to the solid culture medium when solar radiation reaches a preset solar radiation amount.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a novel plant cultivation method using a solid medium.

Plant cultivation methods using a solid medium such as a bag medium are already known. An advantage of this cultivation method is that it can be installed at low cost without a facility for collecting the waste liquid, but has a demerit that irrigation control is required to reduce excess waste liquid from the culture medium.
For example, Patent Documents 1 and 2 describe a method of irrigation control using a water potential (pF value) measured by a tensiometer as an index as an automatic irrigation control technique in hydroponics using a bag culture medium.
Patent Document 3 reports irrigation control using the correlation between the amount of solar radiation and the amount of water absorbed by plants.

JP 2006-197871 A JP 2003-092924 A Japanese Patent Laid-Open No. 2004-008067

In order to grow a plant on a solid medium, the amount of water absorbed by the plant and the amount of water in the medium (which is affected by the amount of irrigation) are important factors. As the stage of plant growth progresses and the leaf area increases, the amount of transpiration increases and the amount of water absorption increases, so it is necessary to increase the amount of irrigation each time. In addition, the amount of irrigation needs to be reduced each time because the transpiration amount and the water absorption amount are reduced by reducing the leaf area in the management work such as the defoliation and pinching of plants. If the amount of irrigation is insufficient, the medium becomes dry. On the other hand, if the irrigation is performed more than necessary, the medium becomes excessively humid. Both the dry state and the overhumid state of the medium adversely affect the growth of the plant.
For example, the method described in Patent Document 3 is a cultivation method that not only shows that it is necessary to increase the irrigation amount according to the progress of the growth stage of the plant, but also reduces the waste liquid outside the medium as much as possible. Therefore, there are the following problems:
・ If the amount of water absorbed by the plant exceeds the amount of irrigation, the waste liquid will disappear and it will be difficult to grasp the water state in the medium.
・ There is a risk of causing extreme water stress in some cases.
・ On the contrary, if the amount of irrigation per solar radiation is increased too much, the inside of the medium will be over-humidified, which will hinder plant growth.
-It takes time and effort for the cultivation manager to grasp the state of plants and the state of moisture in the medium in order to manage liquid supply.
In addition, the tensiometer disclosed in Patent Documents 1 and 2 has a problem that variation in measured values is likely to occur due to the physical properties of the soil and the degree of contact between the unglazed surface serving as a sensor and the soil. It is not desirable to use the pF value as the only irrigation control index.

In addition, it is not impossible as a work to increase the irrigation amount mechanically or artificially according to the growth of the plant. However, the optimal amount of irrigation varies depending not only on the stage of plant growth, but also on environmental factors such as temperature / humidity, day length, season and weather, or the location / region where cultivation is carried out. It is virtually impossible to set and ensure irrigation of an amount corresponding to the amount.
In addition, the appearance of the plant may not reflect the required irrigation volume. For example, when plants are wilted, irrigation may be insufficient, or on the contrary, there may be too much irrigation.
Thus, it is known that the dry state and overhumidity of the medium adversely affect the growth of the plant, but due to the large number of factors to be considered for control and the difficulty of judgment, Until now, setting a suitable amount of irrigation for growth has not been realized.

  An object of the present invention is to provide a method for performing irrigation with a irrigation amount suitable for plant growth as a plant cultivation method using a solid medium.

In view of the above-mentioned problems, the present inventors diligently searched for a method that can reliably control the irrigation amount by considering an index that has a large influence on the water absorption amount of the plant. As a result of finding that there is a possibility of grasping and further researching, the present invention has been completed.
That is, the present invention relates to at least the following inventions:
[1] A method for cultivating a plant using a solid medium that limits the root area,
(A) a step of setting the irrigation amount per solar radiation amount;
(B) a step of setting an upper limit value and a lower limit value of the soil moisture content of the solid medium;
(C) Measure the soil water content of the medium, compare the soil water content with the set upper and lower limits,
(I) If the soil moisture content exceeds the set upper limit, reduce the irrigation amount per solar radiation;
(Ii) If the soil moisture content is below the set lower limit value, increase the irrigation amount per solar radiation amount; and (iii) the soil moisture content is not less than the set lower limit value and the setting A step of adjusting the amount of irrigation by not increasing or decreasing the amount of irrigation per day when the amount of irrigation is below the upper limit, and (d) when the amount of solar radiation reaches a preset amount of irradiation. Providing the solid medium with an amount of water per irradiance adjusted by (c);
The said cultivation method containing.
[2] The method according to [1], further comprising setting the lower limit value higher so that the plant can be cultivated without applying water stress.
[3] The method according to [1] or [2], further including setting a lower limit value so as to allow cultivation under moisture stress.
[4] The method according to any one of the above [1] to [3], wherein the culture medium comprises water purification plant generated soil and coconut shells.
[5] The method according to [4] above, wherein the weight ratio between the water purification plant-generated soil and the coconut shell is 1: 0.8 to 1.2.
[6] (b) An upper limit value and a lower limit value of the pF value are set before the step of setting the upper limit value and the lower limit value of the soil water content of the solid medium, and the pF value of the medium soil and the soil water content The method according to any one of [1] to [5], further including a step of converting the set upper limit value and lower limit value of the pF value into an upper limit value and a lower limit value of soil moisture content from the correlation.
[7] In any one of [1] to [6], the soil water amount and the solar radiation amount are measured by a liquid supply controller including a soil moisture sensor and a solar radiation sensor, and the irrigation amount is controlled by the measured value. Description method.
[8] Supply for use in plant cultivation, comprising a soil moisture sensor and a solar radiation sensor, measuring soil moisture and solar radiation by the soil moisture sensor and solar radiation sensor, respectively, and controlling the irrigation amount by the measured value Liquid control machine.

The method of the present invention measures the amount of solar radiation, and by using a system that combines automatic irrigation in accordance with solar radiation and the measurement of soil moisture content, the soil moisture content as an index for visually observing fluctuations in water absorption by plants Moreover, it is based on controlling the amount of irrigation per solar radiation. Since there is a high correlation between the amount of solar radiation and the amount of water absorbed by plants, irrigation suitable for plant growth is performed by using the solar radiation proportional irrigation control with the amount of solar radiation as an index. Then, the water absorption amount of the plant that fluctuates due to the progress of the growth stage of the plant body and the management work is visually recognized by measuring the soil moisture content, and by controlling the irrigation amount per solar radiation amount, more suitable plant The present inventors have found that the growth conditions can be realized.
The solar radiation proportional irrigation control is a method for managing a normal irrigation amount that increases or decreases the irrigation amount in proportion to the solar radiation amount.
The method of the present invention has the effect of enabling optimal irrigation management regardless of the plant and cropping type to be cultivated.
According to the method further including the step of setting the lower limit value lower or higher in the method of the present invention, a high-yield or high-quality plant can be obtained.

It is a figure which shows the one aspect | mode of the method of this invention. FIG. 2 shows an example of an apparatus for carrying out the method of the present invention.

As described above, the present invention
A method for cultivating a plant using a solid medium that limits the root area,
(A) a step of setting the irrigation amount per solar radiation amount;
(B) a step of setting an upper limit value and a lower limit value of the soil moisture content of the solid medium;
(C) Measure the soil water content of the medium, compare the soil water content with the set upper and lower limits,
(I) If the soil moisture content exceeds the set upper limit, reduce the irrigation amount per solar radiation;
(Ii) If the soil moisture content is below the set lower limit value, increase the irrigation amount per solar radiation amount; and (iii) the soil moisture content is not less than the set lower limit value and the setting A step of adjusting the amount of irrigation by not increasing or decreasing the amount of irrigation per day when the amount of irrigation is below the upper limit, and (d) when the amount of solar radiation reaches a preset amount of irradiation. Providing the solid medium with an amount of water per irradiance adjusted by (c);
It is related with the said cultivation method containing.

  In the present invention, solid medium cultivation that restricts the root area is a solid medium in which the medium in which each plant individual is planted is partitioned by a container or the like and the root area of the plant is limited. The solid medium is typically a medium in a pot or a bag medium.

The step (a), that is, the step of setting the irrigation amount per solar radiation amount is a step necessary for measuring the solar radiation amount and performing automatic watering according to the solar radiation amount based on the measured solar radiation amount. Typically, the amount of irrigation per solar radiation is 0 to 100 ml / MJ.
A solar sensor may be used to measure the amount of solar radiation. By using the solar radiation sensor, it is possible to measure the solar radiation amount more accurately, and automatic irrigation control according to the solar radiation amount is also possible.
The amount of irrigation per solar radiation can be expressed as the amount per strain in view of the common general knowledge in this technical field. In this specification, the amount of irrigation per solar radiation is expressed in units of “ml / MJ”. Unless otherwise specified, the amount of irrigation means the amount per strain.

The upper and lower limits in the step (b), that is, the step of setting the upper limit and lower limit of the soil moisture content of the solid medium are for adjusting the amount of irrigation per the amount of solar radiation set. , A value necessary for performing the subsequent step (c).
Since the amount of soil moisture set varies depending on the medium used, it is preferable to determine the set value based on the correlation with the pF value. Equipment such as a soil pF measuring instrument can be used to set the pF value.
While the amount of soil moisture at which plants normally grow varies depending on the type of medium, pF is generally about pF 1.8 to 3.0. Such a range for pF can be converted for the medium used to determine the upper and lower limits of soil moisture.
In a certain medium, pF1.8-3.0 corresponds to 12-40% as soil water content.

The upper limit and lower limit of the soil moisture content may be changed according to the type of plant and the main purpose of cultivation (yield increase, quality modification, etc.). For example, in tomato, the upper limit is about 11% to about 24. The lower limit is about 8% to about 17%, and these may be combined.
The difference between the upper limit value and the lower limit value, that is, the allowable range of soil moisture content is not limited, and may be about 3% to about 7%.
In this specification, “%” represents volume percent unless otherwise specified.

Step (c), that is, measuring the soil moisture content of the medium, comparing the soil moisture content and the set upper limit value and lower limit value,
(I) If the soil moisture content exceeds the set upper limit, reduce the irrigation amount per solar radiation;
(Ii) If the soil moisture content is below the set lower limit value, increase the irrigation amount per solar radiation amount; and (iii) the soil moisture content is not less than the set lower limit value and the setting The step of adjusting the amount of irrigation by not increasing or decreasing the amount of irrigation per day when the amount is less than the upper limit is required to control the amount of irrigation per day using the amount of soil moisture as a guide. It is a difficult process.

In this process, the amount of irrigation is controlled as follows:
(1) When the amount of soil moisture is not less than the lower limit and less than the upper limit, automatic watering is performed when the amount of solar radiation reaches a certain value.
(2) When the soil moisture content is equal to or higher than the upper limit value, the irrigation amount setting value per solar radiation amount is reduced (in some cases, automatic irrigation per solar radiation amount may be stopped).
(3) If the soil moisture content is less than the lower limit, increase the irrigation amount set value per solar radiation.
Further, in the step (c), by setting the lower limit value to be higher or lower, it becomes possible to cultivate a crop with a higher yield or a higher sugar content. That is, by setting the lower limit value higher (high moisture management), you can grow without applying water stress and increase the yield, while setting the lower limit value lower (low moisture management) and applying water stress Cultivation increases the sugar content of the harvest (fruit). Thus, according to the method of the present invention, it is possible to control the yield or quality of the harvest. Thus, the objectives achieved by using the present invention from this viewpoint and the strategies therefor can be summarized as shown in Table 1 below:

  In a certain medium described above, pF1.8 to 3.0 corresponds to 12 to 40% as the soil moisture content. In this case, the soil moisture content in the low moisture management and the high moisture management is 7 to 12% and 12 respectively. ~ 40%. In high moisture management, it is preferable that the soil moisture content be 12 to 23% because loss of fertilizer and water can be reduced.

  The amount of soil moisture in high moisture management and low moisture management may vary depending on the type of plant. For example, in the cultivation of tomatoes using a certain medium, the lower limit values are about 15% and about 10%, respectively, and acceptable soil. It is preferred that the water content ranges from about 15 to about 20% and from about 10 to about 15%. As the relationship between the soil water content and the pF value in the case of powder, the soil water content of 15-20% corresponds to about pF 2.5-2.8, and 10-15% corresponds to about pF 2.8-3.2, respectively. To do.

Moreover, the rate (amount) of increase / decrease in the amount of irrigation is not limited, and may be determined while monitoring the soil moisture content.
When manually irrigating until the waste liquid comes out from the solid medium at the time of planting, it is not necessary to perform irrigation per day for a certain period immediately after planting (that is, the irrigation amount is 0 ml / MJ). Since the amount of water that the medium cannot hold is given, the soil water content is usually 40% or more and pF1.8 or less.
It is preferable to increase the amount of irrigation per solar radiation depending on the growth stage of the plant. The rate (amount) of increasing the amount of irrigation per solar radiation is typically about 5 to about 40 ml / MJ per time. For example, the irrigation amount is increased by about 8 to about 16 ml / MJ about 1 to 3 weeks after transplanting based on the measured value of the soil moisture content, and thereafter the irrigation amount per solar irradiation amount is appropriately increased.
The amount of increase in irrigation amount per day of solar radiation may be varied by determining an appropriate amount of increase according to the measured soil water content, for example, in increments of about 5 to about 10 ml / MJ, about 12 to about 16 ml / MJ. It may be increased in increments of about 33 ml / MJ.
When using the solar radiation proportional liquid supply controller, the irrigation amount per solar radiation amount may be manually changed to set the irrigation amount.

  For measurement of the soil moisture content, it is preferable to use equipment such as a dielectric constant type soil moisture sensor. With such equipment, it is preferable to measure the soil moisture content not only in the periphery of the culture medium but also in the deeper part.

In the step (d), that is, when the solar radiation reaches a preset amount of solar radiation, the step of supplying the solid medium with the amount of water per unit of solar radiation adjusted in the step (c) includes the step of: It is a process of actually irrigating water. For such irrigation, an automatic irrigation apparatus is preferably used.
In the method of the present invention, the step (d) is performed twice or more in one work, and the step is performed according to a predetermined schedule by automatic management.
The date and interval at which irrigation is started may be appropriately determined. For example, the start is one week after planting the plant, and the interval is every 1 MJ increase in solar radiation.
In addition, the date and interval for starting the adjustment of the irrigation amount per solar radiation amount may be appropriately determined. The date for starting the adjustment is, for example, one week after planting, and the interval is set every week. is there.

The types of plants to which the method of the present invention can be applied are not limited, fruit vegetables such as tomato, eggplant, cucumber, strawberry and melon, leaf vegetables such as komatsuna, spinach, cabbage and lettuce, root vegetables such as radish, carrot, potato and sweet potato, Fruit trees such as mandarin oranges, grapes, figs and blueberries.
The kind of culture medium to which the method of the present invention can be applied is not limited, and examples include rock wool, pearlite, sand, rubble and the like including water purification plant generated soil and coconut shells. As the medium in the method of the present invention, a medium containing water purification plant generated soil and coconut husk is preferable, and the medium in the method of the present invention consisting of water purification plant generated soil and coconut husk is more preferable. Moreover, the thing whose weight ratio of water treatment plant generation soil and palm husk is 1: 0.8-1.2 is still more preferable, and the thing whose weight ratio is 1: 1 is still more preferable.

The method of the present invention is suitably implemented using, for example, the soil moisture sensor 1 and the solar radiation sensor 3. The soil moisture sensor 1 and the solar radiation sensor 3 measure the soil moisture content and the solar radiation amount, respectively, and the irrigation amount is controlled by the measured values (FIG. 1).
The solar radiation sensor 3 is connected to the solar radiation proportional liquid supply controller 2, and opens and closes the electromagnetic valve 4 provided in the liquid supply pipe 5 according to the measured value of the solar radiation amount measured by the solar radiation sensor 3. The medium in which 7 is planted is supplied or irrigated. The soil moisture sensor 1 is connected to a soil moisture recorder 2 'and is used to change the irrigation amount per solar radiation while monitoring the soil moisture amount (FIG. 1). The ratio (speed) of liquid supply is not limited, and is, for example, 2 L / h. A dripper 6 may be provided in the liquid supply pipe 5 to adjust the ratio (speed) of the liquid supply.
According to the present invention, a soil moisture sensor 1 and a solar radiation sensor 3 are provided, the soil moisture sensor 1 and the solar radiation sensor 3 measure the soil moisture content and the solar radiation amount, respectively, and the irrigation amount is controlled by the measured values. A liquid supply controller 8 used for cultivation is also provided (FIG. 2).

  The present invention will be further described with reference to examples. The present invention is not limited to the examples in any way.

Example 1
[the purpose]
The effect of the cultivation method of the present invention is verified.

[Materials and methods]
After determining the correlation between the pF value of the medium to be used and the soil moisture using a multi-capacity soil pF measuring device (manufactured by Daikai Chemical Co., Ltd.) and a soil moisture sensor, Tomato was grown while measuring. The cultivation test areas were as shown in Table 2.

The outline of the test was as follows.
1. Test period July 30-December 24, 2013 Sowing date: July 30 Planting date: September 10 End date: December 24 Test place Inside a house in Tsukuba City, Ibaraki Prefecture 3. Test material, large tomato "Momotaro York" (Takii seedling)
・ 20L bag culture medium (Sumirin Agricultural Products)
・ Soil moisture sensor 5TE (made by Decagon)
・ Data logger Em50 (made by Decagon)
・ Solar radiation proportional liquid supply control machine (made by Meiko Seiki)
・ Liquid fertilizer mixing machine (manufactured by Sanshu Industry)
・ Otsuka House A prescription liquid fertilizer (Otsuka Agritechno)
4). Tomato cultivation method “Momotaro York” was grown in a 3.5 inch pot.
-4 strains were planted in 20L bag culture medium, and repeated cultivation was performed in 11 bags in each test area.
-Invited left and right distribution so that the distance between the stocks was 30 cm. The interval was 1.8m.
-The planting number per 10a was about 2,600.
-Three-stage pinching cultivation was performed, and fruit was picked so that there were 5 fruits per stage.
-A soil moisture sensor was embedded in the bag medium, and soil moisture data was collected using a data logger.
-Irrigation was performed by appropriately changing the irrigation amount while monitoring the soil moisture content, based on the irrigation amount set according to the solar radiation amount, with a solar proportional liquid supply controller.
More specifically, the irrigation amount per insolation amount is (A) 8, 16, 24, 33 ml / MJ at about 8 ml / MJ, (B) 50, 66 ml / MJ at about 16 ml / MJ, or ( C) 100, 133 ml / MJ ~ in about 33 ml / MJ increments, determine the appropriate amount of increase according to the measured soil water content, manually change the setting in the solar radiation proportional liquid supply controller, irrigation amount Adjusted.
In addition, irrigation per day was not performed for a certain period (one week) immediately after planting (that is, the irrigation amount was 0 ml / MJ), and irrigation was manually performed until the waste liquid came out from the solid medium at the time of planting (in Table 3). (September 10) At this time, the amount of water that the culture medium cannot hold was given, so the soil moisture content was 40% or more and pF1.8 or less.
Thereafter, the irrigation amount per day of solar radiation was set to 8 ml / MJ about one week after planting (corresponding to September 17 in Table 3).
Furthermore, as a result of measuring the soil water content on September 24, the low water test area was within 7 to 12%, so the irrigation amount was not changed. In the high moisture test section, the amount of irrigation was increased because the soil moisture content was below the set lower limit of 16%.
Thereafter, the irrigation amount was appropriately changed in order to appropriately manage the soil moisture content by the same operation.
-The fertilizer was applied by diluting the liquid fertilizer using a liquid fertilizer mixing machine so as to be 1/2 unit of Otsuka House A prescription.
-As the soil moisture content changed due to the growth of tomatoes, the amount of irrigation per day was adjusted by increasing / decreasing the amount within the range of 0-100 ml / MJ so as to be within the range of the soil moisture setting value. The standard of increase / decrease in the amount of irrigation was performed in accordance with a normal method in this technical field.
The soil moisture content was measured 2 weeks after planting and was carried out every 3 days to about every other month.

[result]
1. Adjustment and transition of irrigation amount The transition of irrigation amount in each test section is shown in Table 3. Since September 24, the amount of irrigation per solar radiation was adjusted to be lower in the low moisture test group than in the high moisture test group (Table 3).

2. Change in soil moisture The irrigation amount was increased when the soil moisture was below the range of values set for each test section.
The value of soil moisture after October 29 changed within the range of values set in each test section (Table 4).

3. In the growth / low moisture test section of the plant body, due to water stress, the stem diameter was narrow and the leaf length was shortened (Table 5).

4). In the fruit quality and yield / low moisture test section, it was confirmed that the tomato has a higher sugar content and can produce a high sugar content tomato (Table 6).
In the high moisture test, it was confirmed that tomatoes with higher yield and good taste with a sugar content of about 6% can be produced.

[Discussion]
From the above results, according to the cultivation method of the present invention, it was confirmed that a high sugar content tomato can be produced without performing conventional and complicated watering management. Moreover, according to this invention, it became clear that tomato of sufficient sugar content can be produced with a higher yield.
Therefore, the method of the present invention has a remarkable effect that enables easy and reliable control of the quality and quantity of crops. In other words, the method of the present invention is in sharp contrast to conventional methods that require frequent irrigation management based on the experience and intuition of some serious farmers to produce high sugar content tomatoes.

ADVANTAGE OF THE INVENTION According to this invention, the cultivation method which can perform irrigation by the amount of irrigation suitable for plant growth as a cultivation method of the plant using a solid medium is provided.
Therefore, the present invention greatly contributes to the development of plants and flower production industries and related industries.

1: Soil moisture sensor 2: Solar radiation proportional liquid supply controller 2 ': Soil moisture recorder 3: Solar radiation sensor 4: Solenoid valve 5: Liquid supply pipe 6: Dripper 7: Plant 8: Liquid supply controller

Claims (8)

A method for cultivating a plant using a solid medium that limits the root area,
(A) a step of setting the irrigation amount per solar radiation amount;
(B) a step of setting an upper limit value and a lower limit value of the soil moisture content of the solid medium;
(C) Measure the soil water content of the medium, compare the soil water content with the set upper and lower limits,
(I) If the soil moisture content exceeds the set upper limit, reduce the irrigation amount per solar radiation;
(Ii) If the soil moisture content is below the set lower limit value, increase the irrigation amount per solar radiation amount; and (iii) the soil moisture content is not less than the set lower limit value and the setting A step of adjusting the amount of irrigation by not increasing or decreasing the amount of irrigation per day when the amount of irrigation is below the upper limit, and (d) when the amount of solar radiation reaches a preset amount of irradiation. Providing the solid medium with an amount of water per irradiance adjusted by (c);
The said cultivation method containing.   The method according to claim 1, further comprising setting the lower limit value higher so that the plant can be cultivated without applying water stress.   The method according to claim 1 or 2, further comprising setting the lower limit value lower so that cultivation can be performed with moisture stress.   The method in any one of Claims 1-3 in which a culture medium contains a water purification plant generation soil and a coconut shell.   The method according to claim 4, wherein the weight ratio of water purification plant-generated soil to palm shell is 1: 0.8 to 1.2.   (B) The upper limit value and lower limit value of the pF value are set before the step of setting the upper limit value and the lower limit value of the soil moisture content of the solid medium, and the correlation between the pF value of the soil of the medium and the soil moisture content is as described above. The method in any one of Claims 1-5 which further includes the process of converting the set upper limit and lower limit of pF value into the upper limit and lower limit of soil moisture content.   The method according to any one of claims 1 to 6, wherein a soil water amount and a solar radiation amount are measured by a liquid supply controller equipped with a soil moisture sensor and a solar radiation sensor, and the irrigation amount is controlled by the measured value.   A liquid supply controller used for plant cultivation, comprising a soil moisture sensor and a solar radiation sensor, measuring soil moisture and solar radiation by each of the soil moisture sensor and solar radiation sensor, and controlling the irrigation amount by the measured value .