This study was aimed to determine the changes in CO2 concentration according to the temperatures of daytime and nighttime in the CO2 supplemental greenhouse, and to compare calculated supplementary CO2 concentration during winter and spring cultivation seasons. CO2 concentrations in experimental greenhouses were analyzed by selecting representative days with different average temperatures due to differences in integrated solar radiation at the growth stage of leaf area index (LAI) 2.0 during the winter season of 2022 and 2023 years. The CO2 concentration was 459, 299, 275, and 239 μmol·mol-1, respectively at 1, 2, 3, and 4 p.m. after the CO2 supplementary time (10:00-13:00) under the higher temperature (HT, > 18°C daytime temp. avg. 31.7, 26.8, 23.8, and 22.4°C, respectively), while it was 500, 368, 366, 364 μmol·mol-1, respectively under the lower temperature (LT, < 18°C daytime temp. avg. 22.0, 18.9, 15.0, and 13.7°C, respectively), indicating the CO2 reduction was significantly higher in the HT than that of LT. During the nighttime, the concentration of CO2 gradually increased from 6 p.m. (346 μmol·mol-1) to 3 a.m. (454 μmol·mol-1) in the HT with a rate of 11 μmol·mol-1 per hour (240 tomatoes, leaf area 330m2), while the increase was very lesser under the LT. During the spring season, the CO2 concentration measured just before the start of CO2 fertilization (7:30 a.m.) in the CO2 enrichment greenhouse was 3-4 times higher in the HT (>15°C nighttime temperature avg.) than that of LT (< 15°C nighttime temperature avg.), and the calculated amount of CO2 fertilization on the day was also lower in HT. All the integrated results indicate that CO2 concentrations during the nighttime varies depending on the temperature, and the increased CO2 is a major source of CO2 for photosynthesis after sunrise, and it is necessary to develop a model formula for CO2 supplement considering the nighttime CO2 concentration.

서 언
재료 및 방법
    1. 겨울철 CO2 시비 온실에서 온실 온도에 따른 CO2 농도 변화(실험 1의 1, 2차 실험)
    2. 봄철 CO2 시비 온실에서 온실 온도에 따른 CO2 농도변화(2차 실험)
결과 및 고찰
    1. 겨울철 CO2 시비 온실에서 온도에 따른 CO2 농도 변화
    2. 봄철 CO2 시비 온실에서 온도에 따른 CO2 농도 변화
적 요
사 사

• 최수현(한국방송통신대학교 대학원 농업생명과학과 연구원) | Su-Hyun Choi (Researcher, Department of Agriculture and Life Science, Korea National Open University, Seoul 03087, Korea)
• 우영회(국립한국농수산대학교 원예환경시스템학과 교수) | Young-Hoe Woo (Professor, Department of Horticulture Environment System, Korea National College of Agriculture and Fisheries, Jeonju 54874, Korea)
• 장동철(강원대학교 원예학과 교수, 강원대학교 스마트농업융합학과 교수) | Dong-Cheol Jang (Department of Horticulture, College of Agriculture and Life Science, Kangwon National University, Chuncheon 24341, Korea, Department of Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341, Korea)
• 정영애(한국방송통신대학교 대학원 농업생명과학과 연구원) | Young-Ae Jeong (Researcher, Department of Agriculture and Life Science, Korea National Open University, Seoul 03087, Korea)
• 윤서아(한국방송통신대학교 대학원 농업생명과학과 연구원) | Seo-A Yoon (Researcher, Department of Agriculture and Life Science, Korea National Open University, Seoul 03087, Korea)
• 김대현(강원대학교 스마트농업융합학과 교수, 강원대학교 에너지공학과 교수) | Dae-Hyun Kim (Department of Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341, Korea, Department of Biosystems Engineering, College of Agriculture and Life Science, Kangwon National University, Chuncheon 24341, Korea)
• 서호석(㈜시드웨어 대표) | Ho-Seok Seo (Seedware Ltd. Huseok-ro 420 beon-gil 7, Chuncheon-si, Gangwon-do, Republic of Korea)
• 최은영(한국방송통신대학교 대학원 농업생명과학과 교수) | Eun-Young Choi (Professor, Department of Agriculture and Life Science, Korea National Open University, Seoul 03087, Korea) Corresponding author