The objectives of this field trial were to collect reliable measurement data on N₂ emissions and N₂O/(N₂O + N₂) ratios in typical German crops in relation to crop development and to provide a dataset to test and improve biogeochemical models. N₂O and N₂ emissions in winter wheat (WW, Triticum aestivum L.) and sugar beet (SB, Beta vulgaris subsp. vulgaris) were measured using the improved ¹⁵N gas flux method with helium–oxygen flushing (80:20) to reduce the atmospheric N₂ background to < 2%. To estimate total N₂O and N₂ production in soil, production-diffusion modelling was applied. Soil samples were taken in regular intervals and analyzed for mineral N (NO₃⁻ and NH₄⁺) and water-extractable Corg content. In addition, we monitored soil moisture, crop development, plant N uptake, N transformation processes in soil, and N translocation to deeper soil layers. Our best estimates for cumulative N₂O + N₂ losses were 860.4 ± 220.9 mg N m⁻² and 553.1 ± 96.3 mg N m⁻² over the experimental period of 189 and 161 days with total N₂O/(N₂O + N₂) ratios of 0.12 and 0.15 for WW and SB, respectively. Growing plants affected all controlling factors of denitrification, and dynamics clearly differed between crop species. Overall, N₂O and N₂ emissions were highest when plant N and water uptake were low, i.e., during early growth stages, ripening, and after harvest. We present the first dataset of a plot-scale field study employing the improved ¹⁵N gas flux method over a growing season showing that drivers for N₂O and N₂O + N₂ fluxes differ between crop species and change throughout the growing season.

本次田间试验的目的是收集与作物发育相关的典型德国作物的 N ₂排放量和 N ₂ O/(N ₂ O + N ₂ ) 比率的可靠测量数据，并为测试和改进生物地球化学模型提供数据集。使用改进的¹⁵ N 气体通量法和氦氧吹扫 (80:20)测量冬小麦 (WW, Triticum aestivum L.) 和甜菜 (SB, Beta vulgaris subsp. vulgaris ) 的N ₂ O 和 N _{2排放量将大气中的N 2}背景降低至< 2%。为了估算土壤中的 N ₂ O 和 N ₂总产量，应用了产量扩散模型。定期采集土壤样本并分析矿物质 N（NO ₃ ^-和 NH ₄ ⁺）和可水提取的软木含量。此外，我们还监测土壤湿度、作物发育、植物氮吸收、土壤中氮转化过程以及氮向更深土层的转运。在 189 天和 161 天的实验期间，我们对累积 N ₂ O + N ₂损失的最佳估计为 860.4 ± 220.9 mg N m ⁻²和 553.1 ± 96.3 mg N m ⁻²，总 N ₂ O/(N ₂ O + N ₂ ) WW 和 SB 的比率分别为 0.12 和 0.15。生长的植物影响反硝化的所有控制因素，并且作物种类之间的动态明显不同。总体而言，当植物氮和水吸收量较低时，即在生长早期、成熟和收获后，N ₂ O和N ₂排放量最高。我们提出了在生长季节采用改进的¹⁵ N 气体通量方法进行的地块规模实地研究的第一个数据集，表明 N ₂ O 和 N ₂ O + N ₂通量的驱动因素因作物种类而异，并且在整个生长季节发生变化。