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Space and time‐resolved monitoring of phosphorus release from a fertilizer pellet and its mobility in soil using microdialysis and X‐ray computed tomography
Author(s) -
Petroselli Chiara,
Williams Katherine A.,
Ghosh Arpan,
McKay Fletcher Daniel,
Ruiz Siul A.,
Gerheim Souza Dias Tiago,
Scotson Callum P.,
Roose Tiina
Publication year - 2021
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.1002/saj2.20161
Subject(s) - pellet , microdialysis , phosphorus , fertilizer , x ray , computed tomography , tomography , environmental science , pellets , materials science , nuclear medicine , chemistry , agronomy , physics , radiology , medicine , composite material , optics , biology , extracellular , biochemistry , metallurgy
Phosphorus is an essential nutrient for crops. Precise spatiotemporal application of P fertilizer can improve plant P acquisition and reduce run‐off losses of P. Optimizing application would benefit from understanding the dynamics of P release from a fertilizer pellet into bulk soil, which requires space‐ and time‐resolved measurements of P concentration in soil solutions. In this study, we combined microdialysis and X‐ray computed tomography to investigate P transport in soil. Microdialysis probes enabled repeated solute sampling from one location with minimal physical disturbance, and their small dimensions permitted spatially resolved monitoring. We observed a rapid initial release of P from the source, producing high dissolved P concentrations within the first 24 h, followed by a decrease in dissolved P over time compatible with adsorption onto soil particles. Soils with greater bulk density (i.e., reduced soil porosity) impeded the P pulse movement, which resulted in a less homogeneous distribution of total P in the soil column at the end of the experiment. The model fit to the data showed that the observed phenomena can be explained by diffusion and adsorption. The results showed that compared with conventional measurement techniques (e.g., suction cups), microdialysis measurements present a less invasive alternative. The time‐resolved measurements ultimately highlighted rapid P dynamics that require more attention for improving P use efficiency.