Development of Continuous Monitoring Method of Root-zone Electrical Conductivity using FDR Sensor in Greenhouse Hydroponics Cultivation

Jae Seong Lee; Jong Hwa Shin

doi:10.12791/KSBEC.2022.31.4.409

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2022 Vol.31, Issue 4 Preview Page Next Page

Original Articles

Development of Continuous Monitoring Method of Root-zone Electrical Conductivity using FDR Sensor in Greenhouse Hydroponics Cultivation 시설 수경재배에서 FDR 센서를 활용한 근권 내 농도의 연속적 모니터링 방법

31 October 2022. pp. 409-415

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Abstract

Plant growth and development are also affected by root-zone environment. Therefore, it is important to consider the variables of the root-zone environment when establishing an irrigation strategy. The purpose of this study is to analyze the relationship between the volumetric moisture content (VWC), Bulk EC (ECb), and Pore EC (ECp) used by plant roots using FDR sensors in two types of rockwool media with different water transmission characteristics, using the method above this was used to establish a method for collecting and correcting available root-zone environmental data. For the experiment, two types of rockwool medium (RW1, RW2) with different physical characteristics were used. The moisture content (MC) and ECb were measured using an FDR sensor, ECp was measured after extracting the residual nutrient solution from the medium using a disposable syringe in the center of the medium at a volumetric moisture content (VWC) of 10－100%. Then, ECb and ECp are measured by supplying nutrient solution having different concentration (distilled water, 0.5－5.0) to two types of media (RW1, RW2) in each volume water content range (0 to 100%). The relationship between ECb and ECp in RW1 and RW2 media is best suited for cubic polynomial. The relationship between ECb and ECp according to volume moisture content (VWC) range showed a large error rate in the low volume moisture content (VWC) range of 10－60%. The correlation between the sensor measured value (ECb) and the ECp used by plant roots according to the volumetric water content (VWC) range was the most suitable for the Paraboloid equation in both media (RW1, RW2). The coefficient of determination the calibration equation for RW1 and RW2 media were 0.936, 0.947, respectively.

Keywords

calibrated equation

FDR sensor

electrical conductivity (EC)

moisture content (MC)

rockwool

volumetric water content (VWC)

식물의 생장과 발달은 지하부 환경에도 영향을 받으므로 근권 환경의 변수들을 관수전략의 수립에 고려하는 것이 매우 중요하다. 본 연구의 목적은 수분이동 특성이 다른 2종류의 암면배지에서 FDR센서를 활용하여 체적함수율(VWC)과 Bulk EC(ECb) 그리고 식물의 뿌리가 이용하는 Pore EC(ECp)에 대한 관계를 분석하고, 이를 활용하여 이용가능한 근권 환경 데이터 수집과 보정 방법을 확립하고자 진행되었다. 실험은 물리적 특성이 다른 2종류의 암면배지(RW1, RW2)를 사용하였다. FDR 센서를 활용하여 함수율(MC)과 ECb를 측정하였으며, ECp는 체적함수율(VWC) 10－100%에서 배지 중앙부위에 일회용 주사기를 이용하여 배지 잔류 양액을 추출 후 측정하였다. 이후 2종류 배지(RW1, RW2)에 서로 다른 농도(증류수, 0.5－5.0)의 배양액을 각 체적함수율 범위(0－100%)로 공급하여 ECb와 ECp를 측정하였다. RW1, RW2 배지에서 ECb와 ECp의 관계는 3차 다항식에 가장 적합하였다. 체적함수율(VWC) 범위 3차 다항식에 따른 ECb와 ECp의 관계는 낮은 체적함수율(VWC) 10－60% 구간에서 큰 오차율을 보였다. 체적함수율(VWC)범위에 따른 센서 측정값(ECb) 및 식물 뿌리가 이용하는(ECp)의 상관관계는 2종류 배지(RW1, RW2) 모두 Paraboloid 식에서 결정계수(R2)값이 각각 0.936, 0.947로 가장 높았다.

키워드

FDR센서

보정식

암면

전기전도도(EC)

체적함수율(VWC)

함수율(MC)

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Information

Publisher :The Korean Society for Bio-Environment Control
Publisher(Ko) :(사)한국생물환경조절학회
Journal Title :Journal of Bio-Environment Control
Journal Title(Ko) :생물환경조절학회지
Volume : 31
No :4
Pages :409-415
Received Date : 2022-09-16
Revised Date : 2022-10-19
Accepted Date : 2022-10-19
DOI :https://doi.org/10.12791/KSBEC.2022.31.4.409

Journal of Bio-Environment Control ISSN:1229-4675(Print) 2765-3641(Online) 생물환경조절학회지

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