A fertilizer is any organic or inorganic material of natural or synthetic origin (other than liming materials) that is added to a soil to supply one or more plant nutrients essential to the growth of plants. Conservative estimates report 30 to 50% of crop yields are attributed to natural or synthetic commercial fertilizer. It has been estimated that almost half the people on the Earth are currently fed as a result of synthetic nitrogen fertilizer use.
The macronutrients are consumed in larger quantities and are present in plant tissue. Micronutrients are consumed in smaller quantities and are present also in plant tissue.
Only three other macronutrients are required by all plants: carbon, hydrogen, and oxygen. These nutrients are supplied by water (through rainfall or irrigation) and carbon dioxide in the atmosphere.