Impact of solar energy on greenhouse climate and crop production
A 3-year research project was conducted to assess the effect of passive solar energy gains on two differently designed greenhouses, and to determine differences in heating cost. The two greenhouses (PS1 and PS2) were passive solar greenhouses with different design technology. The test crop was tomato (Solanum lycopersicum L. Mountain Magic). Solar energy data along with tomato fruit yield and plant growth characteristics were recorded from November to April in both greenhouses. Greenhouse PS2 maintained significantly (p<0.05) higher interior temperature and photosynthetically active radiation compared with greenhouse PS1. Outdoor heating and light effect on temperature required to heat the two greenhouses was significantly (p<0.05) higher in April compared with the other months. A non-significant difference was recorded between the months of November, December and January for outdoor heating effect. Similarly, non-significant difference between December and January and between March and April were recorded for outdoor light effect on temperature required to heat PS1 and PS2. Higher marketable fruit yield was harvested in PS2, with lower temperature required for heating. This study showed that a PS2-type greenhouse design, with a concrete in-floor active solar heating system, will provide a better crop production environment with reduced heating cost compared with PS1, with a gravel floor.
Rao, S.A., Abbey, L. and Khakbazan, M. (2018). Impact of solar energy on greenhouse climate and crop production. Acta Hortic. 1227, 151-158
sustainable greenhouse design, microclimate, heating temperature, tomato