The book deals with the fundamental aspects of irrigation development, climatic impact on crop production, irrigation requirement estimation, scheduling of irrigation, water measurement, water conservation & harvesting, and economic aspects of irrigation management. Understanding these processes leads to more rational and cost-effective decisions regarding irrigation planning, designing, and implementing irrigation & on-farm water management programs and projects, maintenance practices to maximize performance and reliability. The book's objective is to present the fundamental principles of irrigation need assessment, water relations in the soil-plant-atmosphere continuum, and the principles needed to adopt the most appropriate approach toward irrigation development and management.