• • DGT-measured Se content most accurately reflected soil Se bioavailability, outperforming three traditional extraction methods; 96.7% of soil samples and 66.7% of rice samples met selenium-rich standards, validating DGT's predictive power for practical soil management.
• • Bioconcentration factor (BCF) analysis revealed that Se primarily enriched in rice roots rather than grains, indicating low grain Se accumulation efficiency; this necessitates targeted agronomic strategies to enhance grain Se content.
• • Correlation analysis identified soil pH, organic matter (SOM), cation exchange capacity (CEC), and sulfur (S) content as key factors influencing Se bioavailability; adjusting these parameters can effectively improve Se uptake, offering actionable levers for soil amendment.
• • DGT technology accounts for dynamic resupply from solid phase to solution, overcoming limitations of static equilibrium-based extraction methods; this dynamic simulation of plant uptake provides more reliable risk assessment and resource evaluation.