The scientists compared a solar greenhouse to a plastic one in Ningxia to see how the environment affected plant growth. They measured the temperature and humidity inside both greenhouses. In the solar greenhouse, the air temperature was warmer on sunny and cloudy days compared to the plastic one. The soil was also hotter in the solar greenhouse. The humidity was higher in the solar greenhouse on both sunny and cloudy days but not significantly different in the long run. This study is important for understanding how different types of greenhouses can impact agriculture in the area.