What season's phenological law did Chen Fa describe?

This word describes the phenological law of spring.

According to relevant public information, "Su Wen? According to the theory of four qi regulating spirit, spring is the first of the four seasons, which refers to the period from beginning of spring to long summer, including solar terms such as beginning of spring, rain, fright, vernal equinox, Qingming and Grain Rain. Spring is the season when everything revives. In spring, the climate is warm and mild, and there is rain in most inland areas of China, where everything germinates and the climate is changeable.