Species-specific modeling of biomass accumulation under CO2-light interactions in a smart vertical greenhouse using the Gompertz function

• A CO₂–DLI interaction model was developed for six species using Gompertz kinetics. • Integrated modeling identifies species-specific optimal CO₂ doses for each DLI level. • 1200 ppm CO₂ improved biomass, but optimal values varied across species and light. • A smart EDG-based vertical system enabled precise environmental and temporal control. • The model provides an engineering tool for CO₂-efficient, energy-smart crop production. Rising CO₂ levels and global food demand have increased interest in controlled environment agriculture, where light and CO₂ can be precisely managed. This study examined how CO₂ concentrations of 800, 1000, and 1200 ppm, combined with three daily light integrals (11.5, 14.4 and 17.3 mol·m⁻²·d⁻¹), affect biomass in six leafy vegetables grown in a smart vertical greenhouse. Data from the lowest DLI level (11.5 mol·m⁻²·d⁻¹) were excluded from subsequent analysis because plants showed minimal biomass accumulation. Fresh weight data, modeled with the Gompertz function, showed that increasing CO₂ to 1000 ppm improved growth across all crops. Further gains at 1200 ppm occurred only under higher light, especially for Radish, Basil, and Parsley. Parsley’s biomass rose 25 percent at 1200 ppm under high light intensity, while Mint and Leek showed little change beyond 1000 ppm. These results indicate that the CO₂ level associated with the highest fresh weight depends on both crop type and light intensity. In the tested EDG conditions, 1000 ppm was generally sufficient under moderate light, whereas several crops showed additional gains at 1200 ppm under higher light. Overall, the findings support CO₂ setpoints that are crop- and light-specific within the investigated range.