Abstract:

Based on the meteorological data inside and outside the solar greenhouse in Tai'an City, Shandong Province, this study took northern energy-saving solar greenhouse as the object and systematically analyzed the greenhouse microclimate response law and regulation mechanism under four types of typical winter weather processes, including persistent cooling, low temperature, cloudy and rainy, and warming. The results indicated that: (1) the solar greenhouse maintained thermal stability through the synergistic effect of‘light-heat-soil’ energy transfer and thermal insulation, with the maximum temperature difference between inside and outside of the greenhouse reaching 28.0℃ during sunny days (early morning/noon), and the maximum difference between inside and outside of the greenhouse during cloudy and rainy days being lower than that of sunny days by 8.2℃; (2) soil heat storage capacity decayed with increasing depth, shallow ground temperature variability was significantly smaller on cloudy days than on sunny days, and soil temperature changes lagged behind air temperature, with the lag increasing with increasing soil depth; (3) under persistent overcast conditions, the temperature inside the greenhouse only dropped by 7.3℃ for 47 hours covered by the insulation blanket, which was much smaller than the temperature drop outside the greenhouse (20.5℃), suggesting that soil heat storage and insulation blanket were the core mechanisms for resisting extreme cooling; and (4) in warming weather, greenhouses showed the effect of ‘midday heat concentration’, so agricultural production needed to optimize greenhouse heat storage and humidity reduction through agricultural activities such as early uncovering and late covering of the insulation blanket and ventilation. This study revealed the interactions between the greenhouse microclimate and external meteorological conditions, agricultural management (such as the timing of uncovering the insulation blanket, soil moisture regulation), and proposed effective means to enhance the stability of the greenhouse microclimate. The research results can provide theoretical basis and practical guidance for winter disaster prevention and damage reduction in facility agriculture and efficient utilization of climate resources.

Key words: winter, typical weather processes, solar greenhouse, microclimate, characteristicspatterns