Monitoring Nutrient Dynamics in Hydroponic Systems

In this experiment exclusively, Pi and ${\text{NO}}_3^{-}$ concentrations were monitored in the Hoagland^dil100X solution of the M and NM plants grown in the S-H cultivation system. Twenty ml of Hoagland^dil100X solution was sampled from each bottle after each circulation (T1, T2, T3, and T4). At each sampling time, the solution was collected in 50-ml Falcon Tubes (Sarstedt, Germany) and then stored at 4°C in the dark before proceeding with the analysis.
Concentration of Pi was evaluated via inductively coupled plasma atomic emission spectroscopy (ICP-AES) as described by Garcés-Ruiz et al. (2017 (link)). For ${\text{NO}}_3^{-}$ , samples were first diluted 50 times with Milli-Q water and then analyzed via ionic chromatography system (IC, DIONEX, DX 120). The ${\text{NO}}_3^{-}$ quantification was analyzed under ultraviolet-visible (UV/VIS) spectrophotometry detection between 200 and 220 nm. The limit of detection was <100 ppb.