Plant Physiology, Volume III: Inorganic Nutrition of Plants deals with the inorganic nutrition and metabolism of plants. The book explores the role of elements, other than carbon, hydrogen, and oxygen, which are essential to, or used by, plants in their vital processes. It summarizes the knowledge about mineral nutrition of plants and presents a philosophy of plant nutrition in general. This volume is organized into six chapters and begins with a brief history of mineral nutrition of plants, as well as the media from which plants draw their nutrients, such as the soil and artificial culture medium. The book then discusses the requirements for specific elements, the symptoms incurred by their deficient supply, and the evidence that a given element can be considered essential. The next chapters focus on the inorganic nutrition of microorganisms, general functions of the essential nutrient elements, and the biological situations in which elementary nitrogen is converted to the organic form. The book concludes by analyzing the soil as a complex biological system and its implication for the interpretation of the nutrition of higher plants. This book is a valuable resource for those interested in plant nutrition and plant physiology.