question_answer 15)

Farmers spread manure or fertilizers in the fields, or gardeners use them in lawns or in pots, why these are added to the soil?

Answer:

As plants absorb mineral nutrients from the soil, their amounts in the soil keep on declining. Fertilizers and manures contain plant nutrients such as nitrogen, potassium, phosphorus, etc which need to be added from time to time to enrich the soil.