Abstract:

This study aimed to reveal the seasonal and daily variation rule of meteorological elements inside plastic greenhouse and to establish a microclimate forecast model. The meteorological data inside and outside the strawberry plastic greenhouse was collected in Cixi, Zhejiang province, from 2007 to 2008, to study the seasonal and diurnal variation of air temperature and relative humidity in the greenhouse. The relationship between outside and inside daily maximum temperature, daily minimum temperature were analyzed systematically. The results showed that both the daily maximum temperature and the daily minimum temperature in the greenhouse were higher than that out of the greenhouse, with differences of 5~10℃ and 3~6℃, respectively, for maximum temperature and minimum temperature. The air temperature inside the greenhouse was found to negatively correlate to the relative humidity. Based on these analyses, a temperature prediction model for strawberry plastic greenhouse was developed using stepwise regression method. The verification results from independent experimental data indicated that the R2 between the predicted and observed hourly temperature was 0.912 and 0.887, respectively, for winter and spring. The corresponding RMSE was 2.3℃ and 2.7℃, respectively, for winter and spring. The results of this study can be used to supply support for microclimate forecast and control in plastic greenhouse.