Phosphorus is a finite but crucial resource and is an essential element to all life. Sub-optimal availability and nutrient imbalance in the root zone can adversely impact plant growth, and the quality of food and feed grown on these soils. However, the proven reserves of phosphorus can hardly be adequate for a few centuries only. Yet, its misuse and mismanagement has caused severe problems of eutrophication of water and pollution of the environment. Thus, judicious management of soil phosphorus is essential. This volume is specifically devoted to availability and recycling of phosphorus, regulatory/policy issues of sustainable use of phosphorus, and management in agroecosystems in the context of maximizing the use efficiency and minimizing the environmental risks of water quality.