Nitrogen (N) management in silage corn on sandy soils requires balancing biomass production with nitrate loss. This study evaluated biomass yield, crop N removal, soil, leaf, and pore water N responses to seven N rates (0–470.8 kg N ha⁻¹) at Ona, Florida, in 2025. A randomized complete block design included four replications and 28 plots. Biomass and harvest whole-plant N were measured separately by plot; soil and leaf samples were pooled across four blocks, and pore water from two blocks was pooled by treatment before analysis. Soil nitrate-N (NO₃⁻-N) concentrations were generally greatest at 0–30 cm. Seasonal mean pore water NO₃⁻-N increased from 1.7 mg N L⁻¹ in the control to 46.0 mg N L⁻¹ at the highest N rate. The highest observed mean dry biomass yield was 19.5 Mg ha⁻¹ at 392.4 kg N ha⁻¹, while upper rate means showed limited additional response. Apparent crop N recovery was approximately 71% at 235.4 kg N ha⁻¹ and 36–38% at the two highest rates. Estimated NO₃⁻-N leaching was 9–222 kg N ha⁻¹ using 519 mm of measured drainage; an illustrative ±50% drainage scenario gave 111–333 kg N ha⁻¹ at the highest rate. These descriptive findings indicate increasing nitrate exposure at high N rates under this wet season’s conditions, but do not establish an economic optimum or a transferable N rate threshold.