Rural people say that wheat is covered with soil.

According to our experimental data, we put forward some opinions on the agricultural proverb "beginning of winter is worse than covering the soil": 1. Lower limit temperature of wheat seedling growth: We have tested 7 varieties for 8 years. The lower limit temperature is 0 ~ 4.5℃, and most of them are 3. 1 ~ 3.4℃. According to the field observation, the growth situation was compared when the daily average temperature was 5℃. Therefore, the lower limit temperature is 3℃.