Phosphorus Across the Soil–Water Continuum: Bioavailability, Legacy, and Loss Mitigation

Phosphorus (P) is essential to crop production, yet its management remains inefficient across many soil-water systems. In P-deficient soils, strong sorption, precipitation, limited diffusion and biological constraints reduce plant availability and increase dependence on finite phosphate rock resources. In intensively fertilized or P-rich soils, accumulated legacy P can be mobilized through erosion, runoff, preferential flow and drainage, contributing to downstream eutrophication. Critically, a substantial and sometimes dominant share of P exported via leaching, preferential flow, and artificial drainage moves neither as truly dissolved orthophosphate nor coarse sediment, but as colloidal and nanoparticulate P associated with Fe/Al/Ca (oxyhydr)oxides, clay minerals, and organic matter. Because conventional 0.45 µm filtration operationally classifies these carriers as “dissolved”, routine monitoring can misattribute both the source and the bioavailability of exported P: a blind spot with direct consequences for mitigation design and eutrophication risk assessment. Climate variability, irrigation, soil degradation and changing land use further alter P transformations and transport. Recent advances in sensors, imaging, isotopes, molecular ecology, modelling and precision management provide new opportunities to quantify P availability and loss pathways and to design interventions across the soil-water continuum.This Research Topic will synthesize and advance approaches that improve crop access to soil and recycled P while limiting movement of reactive and particulate P to surface and ground waters. It will connect mechanistic understanding of mineral, organic and microbial P cycling with practical management across contrasting soils, climates and production systems. Priority will be given to studies that quantify trade-offs and test scalable interventions, including 4R nutrient stewardship, placement and timing, crop and root traits, microbial processes, amendments, recovered P products, erosion control, drainage and irrigation management, and decision-support tools. We particularly encourage work that integrates soil P tests with plant response and water-quality outcomes; uses field validation or robust modelling; identifies thresholds and unintended effects; and evaluates performance under climate extremes. The collection aims to support evidence-based recommendations for researchers, land managers, industry and policy. We especially welcome studies that address the temporal mismatch between management intervention and water-quality response: legacy-P drawdown trajectories, hysteresis and lag times, and the transfer of plot-scale evidence to field, catchment, and regional mass balances.We invite Original Research, Reviews, Systematic Reviews, Methods, Perspectives and Brief Research Reports, subject to the article types available in the selected journal. Relevant themes include:• Measurement and prediction of plant-available and legacy P;• Rhizosphere processes, root traits and microbial P mobilization;• Fertilizer, manure, digestate, biochar and recovered-P management;• Dissolved, colloidal, nanoparticulate and sediment-bound P in runoff, erosion, leaching, preferential flow and artificial drainage;• Advances in P characterization and prediction: solution 31P NMR, P K-edge XANES, and other synchrotron speciation, DGT and in-situ flux sensors, field-flow fractionation and single-particle ICP-MS for colloidal P, phosphate oxygen isotopes, remote and proximal sensing, process models, machine learning and decision support;• Conservation practices, buffer systems and nature-based mitigation;• life-cycle, economic, policy and circular-economy assessments. Studies should explicitly connect management to soil P bioavailability, P-use efficiency or water-pollution risk. Purely descriptive studies without a clear management or soil-water linkage will be outside scope; • Coupled biogeochemistry of P with nitrogen, carbon, iron/aluminium/calcium, and trace elements, including redox-driven mobilization in paddy, wetland, ditch and reservoir systems, and the stoichiometric controls on downstream eutrophication response; • P behavior under contrasting edaphic and climate end-members: calcareous, saline and arid soils under treated-wastewater reuse or deficit irrigation, versus humid subtropical paddy. Greenhouse‒vegetables and acid Fe/Al-rich soils. Topic editors: Daniel Menezes Blackburn, Kai Ding, Kamel M. Eltohamy, Dong-Xing Guan, Said Al-Ismaily Source: https://www.frontiersin.org/research-topics/85536/phosphorus-across-the-soil-water-continuum-bioavailability-legacy-and-loss-mitigation