The ¹⁵N gas flux (¹⁵NGF) method allows for direct in situ quantification of dinitrogen (N₂) emissions from soils, but a successful cross-comparison with another method is missing. The objectives of this study were to quantify N₂ emissions of a wheat rotation using the ¹⁵NGF method, to compare these N₂ emissions with those obtained from a lysimeter-based ¹⁵N fertilizer mass balance approach, and to contextualize N₂ emissions with ¹⁵N enrichment of N₂ in soil air. For four sampling periods, fertilizer-derived N₂ losses (¹⁵NGF method) were similar to unaccounted fertilizer N fates as obtained from the ¹⁵N mass balance approach. Total N₂ emissions (¹⁵NGF method) amounted to 21 ± 3 kg N ha^− 1, with 13 ± 2 kg N ha^− 1 (7.5% of applied fertilizer N) originating from fertilizer. In comparison, the ¹⁵N mass balance approach overall indicated fertilizer-derived N₂ emissions of 11%, equivalent to 18 ± 13 kg N ha^− 1. Nitrous oxide (N₂O) emissions were small (0.15 ± 0.01 kg N ha^− 1 or 0.1% of fertilizer N), resulting in a large mean N₂:(N₂O + N₂) ratio of 0.94 ± 0.06. Due to the applied drip fertigation, ammonia emissions accounted for < 1% of fertilizer-N, while N leaching was negligible. The temporal variability of N₂ emissions was well explained by the δ¹⁵N₂ in soil air down to 50 cm depth. We conclude the ¹⁵NGF method provides realistic estimates of field N₂ emissions and should be more widely used to better understand soil N₂ losses. Moreover, combining soil air δ¹⁵N₂ measurements with diffusion modeling might be an alternative approach for constraining soil N₂ emissions.

¹⁵ N 气体通量 ( 15 ^NGF ) 方法可以直接原位定量土壤中的二氮 (N ₂ ) 排放，但缺少与另一种方法的成功交叉比较。本研究的目的是使用¹⁵ NGF 方法量化小麦轮作的N _{2排放量，将这些 N 2}排放量与基于蒸渗计的¹⁵ N 肥料质量平衡方法获得的排放量进行比较，并将 N ₂排放量与¹⁵ NGF 方法结合起来。土壤空气中N ₂的N富集。对于四个采样期，肥料引起的 N ₂损失（^{15 NGF 方法）与从15} N 质量平衡方法获得的未计入的肥料 N 命运相似。N ₂排放总量（¹⁵ NGF 法）为 21 ± 3 kg N ha ⁻¹，其中 13 ± 2 kg N ha ⁻¹（施肥氮的 7.5%）来自化肥。相比之下，¹⁵ N 质量平衡方法总体表明肥料衍生的 N ₂排放量为 11%，相当于 18 ± 13 kg N ha ^{− 1}。一氧化二氮 (N ₂ O) 排放量较小（0.15 ± 0.01 kg N ha ^{− 1}或肥料氮的 0.1%），导致平均 N ₂ :(N ₂ O + N ₂ ) 比率较大，为 0.94 ± 0.06。由于采用滴灌施肥，氨排放量占肥料氮的<1%，而氮淋失可以忽略不计。_{N 2}排放量的时间变化可以通过 50 cm 深度土壤空气中的δ ¹⁵ N _{2得到很好的解释。}我们得出结论，¹⁵ NGF 方法提供了田间 N ₂排放的实际估计，应该更广泛地用于更好地了解土壤 N ₂损失。此外，将土壤空气δ ¹⁵ N ₂测量与扩散模型相结合可能是限制土壤N ₂排放的另一种方法。