Fertilizers relates to inorganic manufactured products that supply plant nutrients. Since the beginning of the 1960s, the large increase in the demand for food, caused by the substantial increase in the world’s population and improved diets, has been met largely by improved agricultural productivity, in which the use of fertilizers played an important role. This text is an introduction for understanding the fertilizers. It is written and designed especially for post-high school students of agriculture, and for fertilizer salesman and distributors who desire to learn more about their products and of their competitors. It will also prove as a tool for testing and quality control of fertilizers.The purpose of this book is to: 1. Understand the relationship between fertilizer use and the environment or crop quality. 2. Understanding the values, composition and other properties of fertilizer materials. 3. Recognize what is in a fertilizer containers and known to calculate plant nutrient content of fertilizer materials. 4. Recognize the different kinds of fertilizer materials. 5. Understanding the chemical constituents of different fertilizer materials and their reaction in soil.