What is the significance of the size of the 24 solar terms?

At dawn, to the south of the Great Wall, except for the southwest plateau and mountainous areas, the daily average temperature is above 22℃. It is the "filling" period of wheat, and the wheat grain looks full, but in fact it is only "half full" and not mature, so it is called "small full", and it is not the time for sickle harvest. Among the 24 solar terms, "mid-April: small is full." This is the best explanation. At this time, wheat is most afraid of the attack of dry and hot wind. During Xiaoman period, there was a great difference in precipitation between north and south of China. The north of Huaihe River is still in a rainy period, so attention should be paid to drought resistance, while the south of the Yangtze River is in a rainy season, so attention should be paid to flood control.