Comparison of Carbon Dioxide Concentration Distribution and Growth of Bell Pepper according to Locations Within a Multi-span Greenhouse

This study was conducted in a 5,200 m 2 plastic multi-span greenhouse to establish an efficient carbon dioxide (CO 2 ) supply strategy by analyzing the distribution of CO 2 concentrations according to greenhouse spatial positions and evaluating the effects of CO 2 concentration variations on growth rate and yield of paprika.The experiment was carried out from February 21 to July 30, 2024, and supplemental CO 2 was not separately supplied during the experiment in order to analyze the spatiotemporal distribution patterns of CO 2 within the greenhouse environment.CO 2 concentrations were continuously measured at upper and lower positions of the plant canopy using Arduino-based CM1107 sensors.Spatially, the greenhouse was divided into front and rear sections, as well as horizontally into left, central, and right positions.Plant growth parameters, including plant height, stem diameter, number of leaves, number of nodes, leaf area, and fresh weight, were measured weekly and statistically analyzed.The relationship between weekly cumulative daily average CO 2 concentration and crop growth rate was evaluated using nonlinear regression modeling.The weekly greenhouse CO 2 concentrations notably decreased immediately after sunrise during the early growth stage due to increased photosynthetic activity, while nighttime CO 2 levels gradually increased throughout the growth period due to biomass accumulation and associated respiratory CO 2 release.Among the positions within the greenhouse, the cumulative daily average CO 2 concentration was highest at position A2F, recording 71,478.14molmol -1 , which corresponded to higher fresh weight and leaf area values of 1,015.77g and 14,416.08cm 2 , respectively.The relationship between weekly cumulative daily average CO 2 concentration and crop growth rate was best described by a Gaussian peak model (R 2 = 0.58).The findings regarding the spatiotemporal distribution of CO 2 concentrations within the greenhouse and the resulting crop growth and productivity from this study could serve as fundamental data useful for establishing greenhouse environmental management strategies.