Spectrophotometric monitoring of the uptake of macronutrients in a pak choi deep water culture
Electrical conductivity (EC) and pH are the principal parameters to control the nutrient solution (NS) in conventional hydroponic systems.
Ion-specific nutrient management (ISNM) promises to increase yields and nutrient use efficiency by solving the problems of the built-up of specific ions and deficiency of others, which are liable to occur using the conventional method of controlling EC and pH only.
Even though Ion selective electrodes are available, implementation of ISNM in horticultural practice still proves difficult.
Prototype systems for the decoupled replenishment of individual ions for a limited set of ions with effective strategies to control the ion interference effect have been developed.
Nevertheless, implementation of ISNM systems in commercial agricultural operations is still difficult due to scarce data on the potential yield and nutrient use benefits and a lack of experience.
This study evaluates the feasibility of spectrophotometric analysis of the NS for reference measurements to verify ISEs readings and assesses the potential applicability of an ISNM approach for pak choi (Brassica rapa var. Chinensis), by closely monitoring ion ratios throughout the cultivation period of 25 days by spectrophotometric analysis in a deep-water cultivation (DWC) system.
The daily uptake of individual ions along with the corresponding daily leave area increment was identified.
No major shifts from the initial ion ratio were observed until after day 18 after transplanting.
During the last week a significant increase in the uptake of NO3- and Ca2+ in respect to the PO43- and
Abel, M., Wittmann, S., Jüttner, I. and Mempel, H. (2023). Spectrophotometric monitoring of the uptake of macronutrients in a pak choi deep water culture. Acta Hortic. 1369, 185-190
DOI: 10.17660/ActaHortic.2023.1369.23
https://doi.org/10.17660/ActaHortic.2023.1369.23
DOI: 10.17660/ActaHortic.2023.1369.23
https://doi.org/10.17660/ActaHortic.2023.1369.23
nutrient uptake monitoring, Brassica rapa var. Chinensis, deep water culture, hydroponic indoor farming
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