Related Experiment Video
Updated: May 9, 2026
Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment
Published on: July 22, 2019
Visualizing Fertisphere Dynamics: High-Resolution Chemical Imaging Reveals Distinct Phosphorus Release Patterns of
Xi-Yuan Li1, Dong-Xing Guan1,2, Paul N Williams3
1Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
Abstract:
Phosphorus (P) deficiency in soils is commonly addressed through phosphate fertilizers, yet millimeter-scale fertisphere dynamics governing fertilizer-soil interactions remain poorly understood, constraining P-use efficiency optimization. This study employed high-resolution chemical imaging to visualize P release patterns, pH dynamics, and acid phosphatase activity in acidic soil fertispheres of contrasting fertilizers: calcium hypophosphite (fast-acting) and apatite (slow-acting). Calcium hypophosphite exhibited rapid dissolution with peak P flux (442 pg cm-2 s-1) at patch edges within 24 h, coinciding with pH elevation that suppressed enzyme activity. Complete dissolution occurred within 48 h. Conversely, apatite released P steadily over 99 days (peak flux: 13.6 pg cm-2 s-1), with release zones shifting inward as H+ consumption generated alkalinization cores. Temporal analysis revealed a 22-day lag between P flux and pH maxima (R = 0.66). These mechanisms demonstrate the importance of matching fertilizer solubility with soil chemistry for precision P management, maximizing bioavailability while minimizing environmental losses.
