The macro-nutrients provided by inorganic fertilizers are—

Plant nutrients are categorized based on the quantities required for growth. Macronutrients are those required in relatively large amounts, while micronutrients are needed in trace quantities [3]. The primary macronutrients provided by inorganic (mineral) fertilizers are nitrogen (N), phosphorus (P), and potassium (K), often referred to by the chemical shorthand N-P-K. These three elements are the most common components of synthetic fertilizers because they are essential for energy metabolism, protein synthesis, and biochemical processes. While calcium, magnesium, and sulfur are also classified as secondary macronutrients [2], they are typically required in smaller amounts than N-P-K. Other elements like iron, boron, zinc, and manganese are strictly classified as micronutrients [1]. Carbon, hydrogen, and oxygen are structural nutrients obtained from air and water rather than primarily through inorganic fertilizers.

Sources

1. [1] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 9: Agriculture > FERTILISERS > p. 302
2. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 3) Agricultural sources: > p. 74
3. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 25: Agriculture > r. Macronutrients: > p. 363