This is the 6259th most frequent Russian word.
удобрениями
The Russian word "удобрениями" means "fertilizers" in English (instrumental plural form).
The word "удобрениями" (by fertilizers) is an instrumental case plural form of the noun "удобрение" (fertilizer), indicating the means by which the action is performed.
Фермер улучшает качество почвы удобрениями.
The farmer improves the soil quality with fertilizers.
Here "удобрениями" denotes the material used for the act of supplementing, emphasizing its instrumental role in plant growth.
Эти растения лучше развиваются при подкормке удобрениями.
These plants grow better when supplemented with fertilizers.
In this phrase, "удобрениями" indicates the objects being experimented upon, showing a flexible use of the instrumental case.