This is the 5576th most frequent Russian word.
посевным
"Посевным" means "sowing" or "related to sowing."
In this sentence, 'посевным' pertains to 'material' indicating that it is intended for sowing seeds.
Этой весной мы готовим посевным материал для новой грядки.
This spring we are preparing sowing material for the new garden bed.
Here, 'посевных' modifies 'areas' and refers to land designated for sowing crops.
Фермер купил новое оборудование для обработки посевных площадей.
The farmer bought new equipment for working on sowing areas.
In this phrase, 'посевные' describes 'plans', indicating that they relate to the act or process of sowing crops.