It is a challenging task to predict the severe consequences of soil health degradation on plants, animals, and human beings. Soil erosion, degradation, nutrient depletion, pollution, organic matter decline, and inadequate management practices have caused Plant nutrient disorders due to imbalances, interactions, deficiencies, or toxicities of one or more plant nutrients. The quality of irrigation water and environmental stress also significantly impact this process. The current book provides insight into the reasons for the occurrence of such nutrient disorders, methodologies to monitor soil, plant, water, and environment, and ways to diagnose the problem through analytical and instrumental techniques. The widespread occurrence of secondary and micronutrient deficiencies in soils has resulted in low uptake of these nutrient ions by plants, which adversely affects human and animal health. Continuous cropping without efficient soil and water use has led to poor crop performance and low yields in many areas. This book answers some pertinent questions on the subject, including why plant nutrient disorders occur, whether they are site or crop-specific, how to diagnose the problem using sound analytical techniques, what the major concerns are, and how to manage such disorders to sustain soil health for crop production. Implementing a scientific soil management program requires good teamwork among scientists, extension workers, and field staff, with governmental support and farmers participation. This book, written in simple language, will be useful for students and teachers of Agriculture, Horticulture, Forestry, Fisheries, and allied disciplines.