Question

What is a fertilizer?

Answer 1

Fertilizers are inorganic substances which are nutrient specific used for growth of plants by increasing the soil fertility (NPK is one of the example)

Answer 2

A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. Many sources of fertilizer exist, both natural and industrially produced.