This book covers the use and dynamics of potassium fertilizers in agriculture. It explores potassium dynamics in soil, phytoavailability, uptake and translocation in crop plants, impact of potassium fertilizers on quality of agricultural produce. Potassium is an essential plant nutrient that has long been overlooked in agriculture of many developing countries. In most of the agro-ecosystems of such countries, potassium balance is negative because its application seldom matches with crop removal. Agro-technicians lack enough skills and resources to promote the right source of fertilizer at the right rate, time and place to facilitate profitable farming. There is a need for farmers to update their farming practices so as to improve the crop yield and quality under unfavorable climatic conditions. Correct application of potassium fertilizers is directly linked with increased crop yield per unit land area in most of the developing countries. Therefore this book fills the gap in the information and provide the readers with latest updates on use of potassium fertilizers. This book contains latest information relevant for graduate students, progressive farmers, extension worker, early career researchers, and policy makers.