This book presents recently-developed crop, soil, and management practices that can be used to improve phosphorous use efficiency in agriculture. Food security highly depends on the availability of plant nutrients such as phosphorus, yet rock phosphate reserves are expected to be exhausted in the next 50¿100 years. Moreover, about 80% of the phosphorous fertilizers applied to soils become unavailable to plants due to phosphorous fixation in iron and aluminum oxides in acidic soils and with carbonates in alkaline soils. As a consequence, only 10-15% of applied phosphorous is up taken by crops. Therefore, there is a need for advanced practices for improving phosphorus use efficiency.