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Table 1 Data used as input for long short-term memory (LSTM) and their ranges

From: Long short-term memory for a model-free estimation of macronutrient ion concentrations of root-zone in closed-loop soilless cultures

Input data (unit) Range
Electrical conductivity (EC) of the substrate (dS m−1) 1.6–4.8
Moisture content of the substrate (%) 29.1–100.0
EC of nutrient solutions in the drainage tank (dS m−1) 0.0–6.0
Volume of nutrient solutions in the drainage tank (L) 0.0–11.3
Cumulative drainage volume per day (L) 0.0–182.2
Volume of nutrient solutions in the mixing tank (L) 1.7–14.1
Mixing volume of drainage (L) 0.0–4.9
Mixing volume of water (L) 0.0–7.5
Mixing volume of stock solution (L) 0.0–0.17
Cumulative irrigation volume per day (L) 0.0–196.0
Preset radiation integral for irrigation control (J cm−2) 0.0–150.0
Target volume of irrigation per dripper (mL) 160.0–220.0
Root-zone temperature (°C) 10.5–44.9
Root-zone pH 2.7–4.6
Light intensity (W m−2) 0.0–492.7
Greenhouse temperature (°C) 10.7–44.3
Greenhouse relative humidity (%) 8.6–83.9
SPAD 40.9–74.7
Plant height (cm) 115.0–217.0
Plant diameter (mm) 13.0–16.8
Number of nodes 16–40