Articles
Development of an ion-selective electrode-based monitoring and dosing channel control system for closed-loop hydroponics
Article number
1426_43
Pages
311 – 316
Language
English
Abstract
Closed-loop hydroponic systems can reduce the use of water and fertilizer compared to open systems.
However, conventional closed systems based on electrical conductivity (EC) control may cause ion imbalances in the nutrient solution over time.
Supplying fertilizers individually based on current ion concentrations in the solution may allow to maintain balance in the nutrient solution.
In this study, a venturi dosing channel control system and an ion monitoring system using ion-selective electrodes was developed for closed-loop hydroponics to adjust the amount of fertilizers variably.
The system was designed to control each solenoid valve for the venturi dosing channel at different time intervals.
Ion monitoring system was consisted of an array of NO3, K electrodes and buffering circuits.
The system was validated at the Gyeonggi Agricultural Research & Extension.
The root mean square error (RMSE) of injected ions mass ratio to the target ion mass ratio was 5.22%, and the minimum error was 0.02%. The RMSE of NO3, K measurements using ISEs were 26.60 and 19.20 mg L‑1, respectively.
The results proved that the developed systems could be applied to ion-specific variable fertigation for the closed-loop hydroponics.
However, conventional closed systems based on electrical conductivity (EC) control may cause ion imbalances in the nutrient solution over time.
Supplying fertilizers individually based on current ion concentrations in the solution may allow to maintain balance in the nutrient solution.
In this study, a venturi dosing channel control system and an ion monitoring system using ion-selective electrodes was developed for closed-loop hydroponics to adjust the amount of fertilizers variably.
The system was designed to control each solenoid valve for the venturi dosing channel at different time intervals.
Ion monitoring system was consisted of an array of NO3, K electrodes and buffering circuits.
The system was validated at the Gyeonggi Agricultural Research & Extension.
The root mean square error (RMSE) of injected ions mass ratio to the target ion mass ratio was 5.22%, and the minimum error was 0.02%. The RMSE of NO3, K measurements using ISEs were 26.60 and 19.20 mg L‑1, respectively.
The results proved that the developed systems could be applied to ion-specific variable fertigation for the closed-loop hydroponics.
Publication
Authors
M.S. Gang, H.J. Kim, W.J. Cho, T.I. Ahn, J.S. Kim, J.Y. Lee, J.E. Hwang, J.W. Jang
Keywords
fertigation, individual fertilizer, ion-specific, venturi, dosing channel control
Groups involved
- Division Precision Horticulture and Engineering
- Division Greenhouse and Indoor Production Horticulture
- Working Group Nettings in Horticulture (subgroup of Protected Cultivation in Mild Winter Climates)
- Working Group Light in Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Vegetable Grafting
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Design and Automation in Integrated Indoor Production Systems
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Greenhouse Environment and Climate Control
- Division Landscape and Urban Horticulture
- Commission Agroecology and Organic Farming Systems
- Division Vegetables, Roots and Tubers
- Working Group Vertical Farming
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