Nitrous oxide (N₂O), a potent greenhouse gas that contributes significantly to climate change, is emitted mostly from soils by a suite of microbial metabolic pathways that are nontrivial to identify, and subsequently, to manage. Using either natural abundance or enriched stable isotope methods has aided in identifying microbial sources of N₂O, but each approach has limitations. Here, we conducted a novel pairing of natural abundance and enriched assays on two dissimilar soils, hypothesizing this pairing would better constrain microbial sources of N₂O. We incubated paired natural abundance and enriched soils from a corn agroecosystem and a subalpine forest in the laboratory at 10-95% soil saturation for 28 hr. The natural abundance method measured intramolecular site preference (SP) from emitted N₂O, whereas the enriched method measured emitted ¹⁵N₂O from soils amended with ¹⁵N-labelled substrate. The isotopic composition of emitted N₂O was measured using a laser-based N₂O isotopic analyzer, yielding three key findings. First, isotopic signatures from natural abundance and enriched N₂O generally agreed in interpretation. Second, our novel pairing of isotopic methodologies refined understanding of microbial N-transformations in drier agricultural soil. In the 50% saturation agricultural soil, nitrification might have been deemed an important process based on SP alone, but enrichment helped reveal that its contribution to N₂O emissions was minor. Finally, we quantified, to our knowledge for the first time, persistent (>50%) β-position-specific enrichment in emitted ¹⁵N₂O, which is far in excess of SP-level fractionation expectations. This counter-intuitive enrichment pattern raises the possibility of previously unrecognized N-transformations in these soils.