What does fertilizer mean?

A fertilizer can be a natural substance (such as manure) or an inorganic substance (nitrates and phosphates). Its purpose is to add minerals to soil that does not have enough to support plant growth. The added material makes the soil more "fertile" by supplying the chemical nutrients that the plants require to grow their best.

Most plants need these six elements in substantial quantities: nitrogen, phosphorus, potassium, calcium, magnesium, sulfur. They also need smaller amounts of other crucial elements.