Optimized irrigation management plays a pivotal role in wheat production in the North China Plain (NCP). However, there exists limited research on the potential impact of different irrigation regimes on the loss of reactive nitrogen (Nr) and the fate of nitrogen (N) within the wheat-soil system. Our study involved an irrigation experiment aimed at quantifying nitrogen-reducing (Nr) while tracing the N fate. Our primary objective was to glean insights into improving nitrogen use efficiency (NUE) and reducing N surplus, thereby enhancing crop yields and minimizing environmental risks. A two-year field experiment involving winter wheat () was conducted in the NCP, employing four distinct irrigation management strategies: I0, pre-planting irrigation; I1, pre-planting + jointing irrigation; I2, pre-planting + anthesis irrigation; I3, pre-planting + jointing + anthesis irrigation. Throughout the wheat growth stages, we measured soil NH and NO emissions alongside yield assessments. The Nr loss, N surplus, NUE and Nr footprint were evaluated. Among the components contributing to Nr loss, ammonia (NH) volatilization was the most significant, accounting for 53.1–58.9%, followed by nitrate (NO) leaching (18.9–23.2%), indirect Nr loss (10.9–12.7%), nitric oxide (NO) emission (4.90–6.02%), nitrous oxide (NO) emission (2.52–3.55%), and ammonium (NH) leaching (2.10–2.58%). NH emission and Nr loss demonstrated a close association with soil moisture levels influenced by irrigation management. Across all treatments, the primary fate of the N input was N uptake, representing 42.7–59.4%, and N surplus, accounting for 28.4–46.0%. Furthermore, NH volatilization, as the leading contributor to total N loss (11.4–12.9% of N input), accounted for 5.70–6.80% of N input. Compared to over-irrigation (I3), the I1 treatment, characterized by supplemental irrigation during the jointing stage, exhibited a remarkable 29.0% ( < 0.05) reduction in N surplus, achieved a higher NUE of 59.4%, and sustained wheat yield, thereby minimizing the Nr footprint. Our findings highlight that supplementary irrigation at the jointing stage effectively mitigates Nr loss and shapes the N fate, resulting in both high NUE and increased wheat yields, while simultaneously reducing the Nr footprint. Our study offers a promising irrigation solution that can contribute to the coordinated development of agricultural production and environmental sustainability.

中文翻译：

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优化灌溉管理可减少活性氮损失并影响小麦生产中的氮命运

优化灌溉管理在华北平原 (NCP) 小麦生产中发挥着关键作用。然而，关于不同灌溉制度对小麦-土壤系统中活性氮（Nr）损失和氮（N）去向的潜在影响的研究有限。我们的研究涉及一项灌溉实验，旨在量化氮还原 (Nr)，同时追踪氮的命运。我们的主要目标是收集有关提高氮肥利用效率 (NUE) 和减少氮肥过剩的见解，从而提高作物产量并最大限度地降低环境风险。在NCP进行了为期两年的冬小麦田间试验，采用了四种不同的灌溉管理策略：I0，种植前灌溉； I1、定植前+拔节灌溉； I2、定植前+花期灌溉； I3、定植前+拔节+花期灌溉。在整个小麦生长阶段，我们测量了土壤 NH 和 N2O 排放量以及产量评估。评估了 Nr 损失、N 剩余、NUE 和 Nr 足迹。造成Nr损失的成分中，氨(NH)挥发最为显着，占53.1%~58.9%，其次是硝酸盐(NO)淋失(18.9%~23.2%)、间接Nr损失(10.9%~12.7%)、硝酸盐(10.9%~12.7%)。氧化物（NO）排放（4.90-6.02%）、一氧化二氮（NO）排放（2.52-3.55%）和铵（NH）浸出（2.10-2.58%）。 NH 排放和 Nr 损失与受灌溉管理影响的土壤湿度水平密切相关。在所有处理中，氮输入的主要归宿是氮吸收，占42.7-59.4%，氮盈余，占28.4-46.0%。此外，NH 挥发是总氮损失（占氮输入的 11.4-12.9%）的主要原因，占氮输入的 5.70-6.80%。与过度灌溉（I3）相比，以拔节期补灌为特征的I1处理氮素盈余显着减少29.0%（<0.05），NUE达到59.4%，并保持了小麦产量，从而最大限度地减少 Nr 足迹。我们的研究结果强调，拔节阶段的补充灌溉可以有效减轻氮流失并影响氮的命运，从而提高氮肥利用效率并提高小麦产量，同时减少氮足迹。我们的研究提供了一种有前景的灌溉解决方案，有助于农业生产和环境可持续性的协调发展。