The most common directin‐situmethod for the measurement of soil denitrification requires many acetylene (C2H2) supply probes and airflow lines to measure nitrous oxide (N2O) flux from the soil under a sealed cover. A modification to this method simplified C2H2supply by placing a single acetylene supply probe 30 cm deep into the soil and measured soil N2O emission flux over a 0.11 m2area. Acetylene concentrations ranging from 0.1–10.0% were readily and predictably established by radial diffusion from the supply probe. Over 94% of the N2O released into the enclosed air space of the soil cover was recovered at an air flow rate of 21 L/h. Recovery decreased rapidly with increased flow rates of 31 and 37 L/h.