Fertilizers are chemical substances that are applied to the soil for supplying essential nutrients required by plants. They are used as a part of nutrient management practice for enhancing the agricultural productivity or crop yield. Fertilizers can be classified into two categories, namely, organic fertilizers and inorganic fertilizers. Organic fertilizers are natural fertilizers derived from plants and animals. They have various benefits such as promoting the reproduction of microorganisms, enriching the soil with carbonic compounds, altering the physical and chemical properties of soil, and increasing the content of organic matter in the soil. Inorganic fertilizers are chemical-based fertilizers used for providing nutrients for the development of crops. These can be further classified into nitrogen fertilizers and phosphorous fertilizers. Although fertilizers are beneficial for soil and productivity, excessive application of fertilizers may also lead to soil fertility degradation. This book includes some of the vital pieces of works being conducted across the world on various topics related to fertilizers, crop yield and nutrient management. This book will serve as a reference to a broad spectrum of readers.