KR20150068754A - Method for controlling irrigation amount in soilless culture - Google Patents

Abstract

The present invention relates to a supply amount control method of a culture medium during soilless cultivation of crops, regarding a control method of a supply amount of a culture medium supplied during soilless cultivation of crops, which comprises: a data collection step for collecting data of a light intensity and a transpiration amount by measuring a plurality of times of the light intensity of crops received and the transpiration amount of the crops; a relation formula determination step for determining a relation formula through a correlation between the light intensity and the transpiration amount collected in the data collection step; and a culture medium supplying step for supplying a culture medium to the crops with respect to an accumulated amount of insolation calculated by applying the relation formula. According to the present invention, a supply amount control method of a culture medium can increase efficiency of irrigation and, particularly, can have effects in controlling oversupply of a culture medium under a climate condition such as Korean summer by precisely examining a relation between a light intensity and a transpiration amount in soilless cultivation, compensating for a light intensity value, and accurately forecasting a supply amount of a culture medium.

Description

METHOD FOR CONTROLLING IRRIGATION AMOUNT IN SOILLESS CULTURE FIELD OF THE INVENTION [0001]

More particularly, the present invention relates to a method for controlling the amount of light intensity and transpiration rate in supplying a nutrient solution to a crop grown in an artificial medium, And more particularly, to a method of accurately determining the relationship and controlling the supply amount of the culture liquid effectively.

Non-soil cultivation involves cultivating crops in an artificial medium without soil, cultivating them by supplying a culture medium, and hydroponic cultivation.

Non-soil cultivation can be harvested in a short period of time and can be cultivated in a place where it is impossible to cultivate because it is much less dominated by natural environment than in soil cultivation. Crops are on the rise.

The productivity of crops cultivated by non soil cultivation is closely related to irrigation management and the improvement of efficiency of water and nutrient utilization by proper irrigation management is one of the important factors for cost reduction of cultivation without soil.

Irrigation management is usually done in such a way that when a certain amount of solar radiation is accumulated, the same amount of culture medium is supplied every accumulation time, and cumulative solar radiation is based on the amount of evaporation (De Pascale et al., 2011; Tao et al., 2011; Ta et al., 2012).

Although the amount of irradiation (or light intensity) varies depending on the region, the latitude or the season, the method of supplying the culture liquid is based on the estimated amount of evaporation, ignoring the change in the amount of solar radiation It is possible to make an error in calculating the amount of the culture liquid. The error between the actually required culture medium and the presumed culture medium becomes larger in an extreme environment where the light condition is high or low and the variation of the light intensity is large.

Therefore, it is necessary to study effective water management methods that can reduce the waste of water and nutrients by measuring accurate solar radiation and transparency.

Korean Patent Laid-Open Publication No. 10-1999-0085172

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve such conventional problems, and it is an object of the present invention to provide a method for cultivating a crop in a soil-free environment such as an artificial medium by observing the relationship between the luminosity and the amount of the growth, A supply amount control method of the present invention.

In order to accomplish the above object, a method of controlling the supply amount of a culture solution to be supplied in the cultivation of a non-soil cultivation of a crop according to an embodiment of the present invention is a method of controlling the amount of light supplied to the crop, A data collecting step of collecting data; A relational expression determining step of determining a relational expression through a correlation between the luminous intensity and the amount of vaporized light collected in the data collecting step; And a culture liquid supplying step of supplying the culture liquid to the crop according to the cumulative irradiation dose calculated by applying the relational expression to minimize the difference from the amount of the culture liquid required by the crop.

In the data collecting step, the luminous intensity and the quantity of vaporization are continuously measured by measuring at a constant time interval, and the time interval is 1 to 60 minutes.

The relational expression determination step is characterized by analyzing a relationship between the luminous intensity and the amount of vaporization through a regression analysis, and deriving the relation expression by compensating the luminous intensity.

And the correlation between the luminous intensity and the vaporization amount is expressed by the following equation.

[Mathematical Expression]

(In the equation, x is the light intensity (W / m ^2), y is transpiration (g / m ² · s), and, a, b, c and x ₀ is a regression coefficient which is determined by the x and y)

Wherein the crop is paprika,

In the above equation, a is 234.972, b is 40.910, c is 28.101, and x ₀ is a value of 81.605.

The culture liquid supply step is characterized in that the culture liquid is supplied at a time when the cumulative solar irradiation amount reaches 100 J / cm 2.

By precisely identifying the relationship between the luminosity and the volume of production, it is possible to compensate for the luminosity value, thereby accurately estimating the amount of the culture medium to be fed, thereby improving the efficiency of the irrigation. Especially, it is effective to reduce waste caused by excessive supply of culture medium in a region where solar radiation is large as in the summer of Korea.

Thus, it is economically advantageous to reduce the waste of water and nutrients by controlling the feeding amount of the effective culture liquid, and it is possible to prevent the drought or the salt obstruction caused by underestimation or overestimation of the evaporation rate by supplying the accurate amount of culture liquid.

In addition, the method of controlling the amount of the culture solution according to the present invention is excellent in crop growth, fruit yield and quality by supplying the culture solution by calculating the optimum amount of tubules.

In addition, the load of environmental pollutants such as groundwater contamination caused when the culture liquid supplied in excess of the amount required for the crop is discharged to the outside can be reduced.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

FIG. 1 is a flowchart sequentially illustrating a method of controlling the amount of a culture medium supplied to cultivate a non-soil of a crop according to an embodiment of the present invention.
FIG. 2 (a) is a graph showing an estimated increase in the amount of crop per unit leaf area per summer in summer and the amount of increase measured at intervals of 1 minute, 10 minutes, and 60 minutes, , And the amount of evaporation measured at intervals of 1 minute, 10 minutes, and 60 minutes, respectively.
3 is a graph showing an estimated value, a measured value, a correction value and a luminous intensity of the evaporation amount in the summer.
FIG. 4 is a graph showing the average tubing yield, drainage and evaporation amount per crop during a day, where A is summer and B is winter.
FIG. 5 is a graph showing the average tubing yield, drainage and evaporation per crop per month, with C being summer and D being winter.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless defined otherwise, all terms used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the method for controlling the supply amount of the culture solution supplied in the cultivation of the non-soil of the crop according to an embodiment of the present invention includes a data collection step S10, a relational decision step S20, S30).

Here, the culture liquid is obtained by dissolving the inorganic nutrients necessary for the growth of crops in water in accordance with the ratio of each absorption amount, and is also referred to as nutrient solution.

Light intensity means radiation intensity, that is, intensity of light, and accumulated radiation means amount of solar energy reached for a certain period of time.

The transpiration rate refers to the amount of evaporation on the surface of the crop.

Irrigation refers to the supply of the culture medium, and the flow rate refers to the amount of the culture medium supplied to the crop.

The data collecting step S 10 is a step of collecting data on the luminosity and the volume of production by measuring the luminosity of the crop and the quantity of the crops, and this step is for collecting continuous data on the luminosity and the volume of the cultivation.

Since the relationship between the luminosity and the amount of evaporation can be determined by collecting a plurality of data, the luminosity and the amount of evaporation can be measured a plurality of times.

It is preferable that the measurement is carried out at a constant time interval in the measurement of the light intensity and the quantity of the plural times, and the constant time interval may be 1 minute to 60 minutes.

The relational expression determination step S20 is a step of determining a relational expression through the correlation between the luminous intensity collected in the data collecting step S10 and the amount of the increase.

The process of determining the relation through the correlation between the luminosity and the vaporization amount is as follows.

In general, the evaporation estimate model is estimated as the modified equation 1 from the Penman-Monteith equation simplified by Baille et al. (1994).

[Formula 1]

(E _t is transpiration rate (g · h ^-1), RAD incident light amount ^{(μmol · m -2 · s -1} ), VPD is a water vapor pressure gun carriage (㎜Hg), LAI is leaf area index, k is the extinction coefficient, a , b is (a ^{g · μmol -1 · m -2,} g · h -1 · ㎜Hg -1) parameters

In Equation (1), VPD is one of the main factors directly affecting the estimation of the amount of evaporation, but is assumed to be a constant since the atmospheric temperature and relative humidity are kept constant at the crop growing site.

Therefore, Equation 1 can be simplified as Equation 2 below, which has a linear relationship.

[Formula 2]

(E _t is the rate of evaporation (g · h ^-1 ), and a and b are coefficients)

From the statistical analysis of the data of the luminosity and the amount of evaporation, the luminosity and the amount of evaporation per leaf area of the crop can be accurately expressed by a nonlinear curve-fitting sigmoidal function as shown in the following Equation 3, rather than Equation 2 above.

Here, data statistical analysis was done through regression analysis.

[Formula 3]

(where x is the luminosity (W / m ² ), y is the quantity of evaporation (g / m ² · s), and a, b and x ₀ are regression coefficients determined by x and y)

(Gonzalez-Dugo et al., 2010), the difference between the actual and the expected amount of evaporation is reduced through Equation 3. However, when the light intensity is high, the pore of the crop is closed and the rate of evaporation decreases. 2007; Kuiper, 1961), the actual amount of solar radiation to control the amount of water should be lower, considering that it is lower than the estimated amount of evaporation under high light conditions.

Accordingly, the luminosity value of Equation 3 was compensated, and the relationship between the luminosity and the quantity of vaporization as in the following equation was determined.

[Mathematical Expression]

(In the equation, x is the light intensity (W / m ^2), y is transpiration (g / m ² · s), and, a, b, c and x ₀ is a regression coefficient which is determined by the x and y)

When the cultivated crop is paprika, the regression coefficients for each of the above equations are 234.972 for a, b for 40.910, c for 28.101, x ₀ for 81.605, The amount of evaporation can be found to have the relationship shown in Equation 4 below.

[Formula 4]

The culture solution supply step S30 is a step of calculating the cumulative solar irradiation dose by applying the relational expression determined in the relational expression determination step S20 and supplying the culture solution to the crop.

A predetermined amount of the culture liquid can be supplied at each time when the cumulative irradiation dose reaches a predetermined value.

A certain amount of culture liquid can be supplied at every time when the cumulative irradiation amount becomes 100 J / cm 2.

Since the cumulative irradiation dose is calculated using the above equation, the amount of cultivation can be precisely predicted at a changing light intensity, unlike the case of applying the estimated growth rate of Equation 1, so that only the required amount of the culture can be supplied.

Hereinafter, the present invention will be described in detail with reference to specific examples.

Crop growth conditions

Experiments were carried out using paprika in a venlo-type greenhouse in a research farm at Seoul National University in Suwon. The paprika seedlings were transferred to a rock slab of 0.9m (L) × 0.15m (W) × 0.07m (H). After 10 days of being transferred to the rocky cube, roots began to flow to the bottom of the cube and the slab was placed in a gutter with a crop density of 3 plants · m ^-2 .

Three watering monitoring and control systems and 18 whole crops were used to estimate the volume and volume.

The experiment was conducted twice in summer and winter from February 2011 to March 2012.

The microclimate of daytime temperature, nighttime temperature and relative humidity was automatically maintained by environmental control system within 25 ~ 30 ℃, 15 ~ 22 ℃, 50 ~ 80% respectively.

The used culture medium had an electrical conductivity of 2.6 to 3.0 dS · m ^-1 and a pH of 5.5 to 6.5, and the supply of the culture solution was carried out when the cumulative solar irradiance reached 100 J / cm ² .

Measurement of volume

The evaporation was measured by an irrigation monitor and control system (Seoul National University).

The amount of culture fluid, culture medium, microclimate and root area environmental conditions (water content and electrical conductivity of substrate) absorbed by each crop were measured at 5 second intervals by a precision water monitoring and control system.

Evaporation was measured every 10 minutes at most to obtain a value with an error of less than 5%.

LAI was measured weekly by measuring leaf length and width during the experiment.

Estimation model

The rate of evaporation was measured by equation 1 above, which is a modified equation from the Penman-Monteith equation.

In Equation 1, a, b, and k values are 4.25, 0.009, and 0.84, respectively, and VPD is assumed to be a constant since the atmospheric temperature and relative humidity of the greenhouse are controlled to have a constant value.

Experimental Method

The relationship between rate of proliferation and intensity was investigated and compared using consecutive day-to-day cumulative data for 85-115 days (Days After Transplanting, DAT 85-115) after a transit in summer and winter (LAI = 3.0 - 3.5).

The exact amount of evaporation measured by the irrigation monitoring and control system was compared to the estimated evaporation from equation 1 above. The amount of evaporation was determined based on the weight change of the crop for a unit time.

In addition, the relationship between the amount of evaporation measured at time intervals of 1 minute, 10 minutes, and 60 minutes and cumulative solar radiation was compared.

The amount of evaporation per leaf area was estimated using the luminous intensity and LAI data from Equation 1 above.

Based on these results, the difference between cumulative solar irradiance and the amount of culture supplied in summer and winter was compared between conventional and modified irrigation methods.

In the conventional irrigation method, the cumulative irradiation dose is calculated according to Equation (1) to supply the culture liquid, and the modified irrigation method means that the cumulative irradiation dose is calculated according to the present invention to supply the culture liquid.

Data Analysis

Data were analyzed with statistical analysis program SAS 9.0. The relationship between immediate lightness and vaporization was fitted with a negative exponential curve. The graph is represented by SigmaPlot.

Derive accurate relationship of luminosity and vapor volume

As shown in the graph shown in FIG. 1, the peak of the intensities of the interior of the greenhouse in the experimental site was higher in summer than in winter, and the variation of light intensity during the day was 0-700W / m ^{2 in} summer (0-400W / m ² ) . The peak of summer luminosity is almost twice as high as that of winter luminosity, and the cumulative solar radiation during the day is not much different from summer to winter, even though Gwangju is more in winter than in summer.

The amount of evaporation was used to determine the required volume of water and was calculated daily based on the cumulative solar radiation in the Penman-Monteith equation. Even though cumulative solar irradiance is kept constant irrespective of luminosity every day, the amount of evaporation can be different due to fluctuation of luminosity during daytime.

Particularly, as the variation of the luminous intensity becomes larger under the condition of high luminous intensity, the evaporation is further suppressed. In addition, variations in light intensity can be large depending on the area where the crop grows, latitude and climatic conditions.

For this reason, accurate measurement of the luminous intensity is required for accurate calculation of the cumulative solar irradiance reflecting the amount of evaporation. Through statistical analysis of the evaporation data, the inventor has derived a relational expression between the luminosity and the evaporation amount of the formula.

[Mathematical Expression]

(In the equation, x is the light intensity (W / m ^2), y is transpiration (g / m ² · s), and, a, b, c and x ₀ is a regression coefficient which is determined by the x and y)

Here, the regression coefficients a, b, c, and x _o were 234.972, 40.910, 28.101, and 81.605, respectively. From these results, the compensated luminosity was applied to determine the required tube volume.

The measured and corrected values of the luminosity actually measured through the experiment are shown in the graph of FIG. 2, and the cumulative solar irradiance and the number of the irrigation water for one day are shown in Table 1 based on this relationship.

In the following Table 1, the correction value means a value obtained by an equation which is a relation between the light intensity and the amount of vaporization in which the actual light intensity is compensated. In other words, the dependent variable for the light intensity correction is the quantity of evaporation, and the relationship between the light intensity and the evaporation quantity is obtained by the reaction of the crop to the instantaneous light intensity based on the evaporation quantity, The brightness value is calculated and is referred to as a correction value.

The accumulated amount of light intensity actually irradiated per day was compared with the accumulated amount of light intensity corrected by the relational expression, and the amount of water supplied at that time was compared.

August 22, 2011 Measures Correction value Cumulative solar radiation
(MJ / cm ² ) 512.80 475.37 Tube length
(ml) 1125 900

In the case of paprika cultivation, when the 30% yield is maintained in the optimal root area, if the calibrated light intensity is used to determine the flow rate, the amount of culture medium supplied can be reduced by more than 10%.

In detail, when the culture liquid is supplied based on this amount of increase, it is controlled on August 22, 2011 by the conventional method (supply of 225 ml of culture liquid every time when the cumulative solar irradiance reaches 100 J / cm 2 according to Formula 1) Five irrigation occurrences and four irrigation occurrences when controlling the irrigation volume according to the amount of accumulated solar radiation calculated by the present invention.

On the other hand, the variation of light intensity was not large in the winter on January 14,

In other words, the condition of the amount of light fluctuation and the condition of high light intensity have a large difference between the estimated amount of evaporation and the actual amount of evaporation, so that the culture was supplied in an amount exceeding 10% in the same climate as the summer in Korea, Eventually, unnecessary nutrients and water are wasted.

Comparison of crop growth

Whether culturing was effected in accordance with the conventional method and the method of the present invention when the culture was supplied was evaluated.

The height of each crop, the number of nodes, LAI, and the number of fruits were measured in summer and winter and are shown in Table 2 below.

In Table 2, "Comparative Example" is based on a conventional method in which the supply amount of the culture liquid is controlled by Equation 1, and "Embodiment" is a method in which the supply amount of the culture liquid is controlled by the equation will be.

summer winter Comparative Example Example Comparative Example Example Height
(cm) 160.8 162.1 205.2 208.2 Number of nodes 28.3 28.1 32.3 32.9 LAI 3.37 3.24 3.52 3.67 Number of fruits 8.8 9.1 10.8 10.1

As shown in Table 2 above, controlling the supply of the culture medium based on the corrected luminosity did not affect crop growth.

Conventionally, since a larger amount of the culture liquid is supplied than the amount required by the crop, a decrease in the culture liquid supply amount does not affect the growth of the crop.

From these results, it was found that the use of calibrated luminosity in determining tubal yield did not affect fruit yield and quality of paprika crops, especially in the summer.

The scope of the present invention is not limited to the above-described embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (6)

A method for controlling the supply amount of a culture medium to be supplied in the cultivation of a non-soil crop of a crop,
A data collecting step of collecting data of the light intensity and the amount of evaporation by measuring the light intensity received by the crop and the evaporation amount of the crop a plurality of times;
A relational expression determining step of determining a relational expression through a correlation between the luminous intensity and the amount of vaporized light collected in the data collecting step; And
And a culture solution supply step of supplying the culture solution to the crop according to the cumulative solar irradiation dose calculated by applying the relational expression to minimize the difference from the amount of the culture solution required by the crop.
The method according to claim 1,
Wherein, in the data collection step, the luminosity and the amount of the deposition are continuously measured while being measured at regular time intervals, and the time interval is 1 to 60 minutes.
The method according to claim 1,
In the relational expression determination step,
Wherein the relationship between the luminosity and the amount of evaporation is analyzed through regression analysis, and the relation is derived by compensating for the luminosity.
4. The method according to any one of claims 1 to 3,
Wherein the relationship expressing the correlation between the luminosity and the amount of vaporization is expressed by the following equation.
[Mathematical Expression]

(In the equation, x is the light intensity (W / m ^2), y is transpiration (g / m ² · s), and, a, b, c and x ₀ is a regression coefficient which is determined by the x and y)
5. The method of claim 4,
Wherein the crop is paprika,
Wherein a is 234.972, b is 40.910, c is 28.101, and x ₀ is a value of 81.605.
The method according to claim 1,
Wherein the culture liquid is supplied at a time point when the cumulative solar irradiance reaches 100 J / cm 2.

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