This document summarizes essential plant nutrients and fertilizers. It discusses macronutrients and micronutrients that plants require, as well as the functions and deficiency symptoms of primary nutrients (nitrogen, phosphorus, potassium), secondary nutrients (calcium, magnesium, sulfur) and micronutrients (iron, copper, zinc, boron, etc.). It also describes different types of fertilizers including organic and inorganic, soluble and insoluble, and methods of applying fertilizers such as banding, sidedressing, topdressing, and fertigation.