Phosphorus and its utilization in soils of dry regions

This review deals with selected aspects of the forms, behavior and utilization of phosphorus in soils of dry regions. Such regions embrace most developing nations in the world. Amounts and major forms of phosphorus in the soils, indices of availability, fertilizer sources, initial and residual effects, modes of application and possibilities for improved utilization are considered. The supply and availability of phosphorus is a key factor in crop production. Consequently, for appreciable increases in production in dry regions, improvements in utilization of phosphorus are needed. Several possible improvements are therefore proposed as the final part of this paper.