Abstract:Light is the main energy source of solar greenhouse. The change of outdoor light and temperature will cause internal environmental parameters. Light intensity, air temperature and humidity are important factors affecting the rate of plant photosynthesis. Therefore, it is important to study the changing trend of light intensity, air temperature and humidity in greenhouse to guide crop production in greenhouse. In this experiment, the sunken solar greenhouse was taken as the research object, and the wireless sensor network was used to realize the real-time collection of light intensity and air temperature and humidity. Through the analysis of the variation trend of the light intensity, air temperature and humidity, the variation trend of light intensity at the observation points can be obtained, which were located on the south (S), north wall (N), east (E), west (W), middle (M) of the greenhouse interior and outdoor (O) of the greenhouse, also the variation characteristics of air temperature and humidity at different locations within 1/2 section of the greenhouse span. The results showed that the average of light intensity at daytime during summer sunny weather in descending order was as follows: observation points O (68267lx), S (53359lx), M (44770lx), W (44141lx), N (38907lx) and E (28615lx). The light environment in the north and south direction was more similar to that in the east and west sides. The average of temperature at daytime in the greenhouse was higher than 35℃, and the average of relative humidity at daytime was lower than 50%, which was harmful to crops. On cloudy days in summer, the overall light in the greenhouse was weak, but the overall temperature, light and wet environment of the greenhouse was more uniform than that on sunny days in summer. In the area around the north wall, the light was obviously insufficient (the average of light intensity at daytime was 7985lx).
