Where does “яровизация” come from?

яровизация (Russian) comes from Russian яровой, from Proto-Slavic jarovъ, from Proto-Slavic *jaro, from Proto-Indo-European yóh₁r̥ — year.

Ancestry of “яровизация”, step by step

Step	Language	Word	Meaning
1	Russian	яровой	spring
2	Proto-Slavic	jarovъ	—
3	Proto-Slavic	*jaro	—
4	Proto-Indo-European	yóh₁r̥	year

яровизация — Etymology, Origin & Word History | Etymology Explorer