Advances in understanding plant root uptake of phosphorus

At a global scale, phosphorus (P) deficiency comprises a large area of cropland, while P has also been used in excess of crop requirements in many other regions. Improved crop P-acquisition efficiency would allow lower target critical soil P values and provide savings in P-fertiliser use. At the same time, it would reduce P lost through erosion, leaching and/or soil sorption. This chapter summarises the progress in research on root traits associated with P acquisition, including root morphology, architecture, biochemistry, colonisation by arbuscular mycorrhizal fungi, and fine root endophytes, and the trade-offs among all these traits. Farming-management practices to improve P acquisition under current intensive agricultural systems are also discussed. The chapter summarises breeding progress in improving P-acquisition efficiency. In the face of soil P deficiency or legacy P globally, the chapter suggests future directions to improve P acquisition in five key areas.