Management of soil phosphorus (P) remains a crucial issue for the economic and environmental sustainability of agriculture and natural ecosystems globally. It is therefore essential that we have appropriate understanding of the mechanisms by which plants are able to acquire P from soil. In this chapter, various processes and physiological traits of plants that facilitate the availability and acquisition of P from soil are outlined, and some possibilities for deploying these traits into agricultural germplasm discussed. Better understanding of these processes and the development of improved germplasm may ultimately improve the P-use efficiency of agricultural systems and provide valuable information for wider-scale land and resource management. However, at present it is evident that the full extent of the complexity of the gene-by-gene and gene-by-environment interactions that are associated with plant P nutrition are not well appreciated. It is therefore important that a systems approach to P management continues to be developed for a more sustainable agriculture.