There is keen interest to enhance denitrification within intervening aquatic habitats between agricultural areas and downstream aquatic ecosystems to reduce nitrogen (N) loading impacts to receiving ecosystems. We conducted a series of measurements to examine whole system in situ diel denitrification estimates in experimental ditch and stream environments using a Bayesian one‐station diel N₂ flux model. Model estimates revealed complex patterns that indicate fluxes may be controlled by the balance of both N₂ production via denitrification and consumption driven by physical or biological processes associated with strong diel patterns in environmental conditions. We investigated potential improvements in model fits to observed data associated with the addition of a N₂ consumption term to represent biological (N₂ fixation) or physical (bubble formation and N₂ scavenging) mechanisms associated with daytime photosynthesis. We also expanded the current one‐station diel flux model to a two‐station model to estimate denitrification in discrete reaches. Our modified diel N₂ flux models improved model fit significantly across three metrics (Nash–Sutcliffe efficiency, root mean square ratio, and percent bias) increasing their utility in shallow, open canopy, lotic systems. While more studies are needed to understand specific mechanisms associated with N₂ consumption processes in small agricultural drainages as well as environmental conditions affecting their relative importance, these results improve estimates of N₂ flux where dynamic conditions and heterogeneity of habitats create severe diel patterns in factors controlling dissolved gas concentrations and prohibit accurate estimates of N₂ flux using existing models.

中文翻译：

---

识别反硝化和氮消耗量可改善物流diel N2通量模型的性能

人们强烈希望在农业区域和下游水生生态系统之间的水生生境中加强反硝化作用，以减少氮对接收生态系统的影响。我们进行了一系列测量，以使用贝叶斯单站Diel N ₂通量模型在实验沟渠和河流环境中检查整个系统的原位diel反硝化估计。模型估计值揭示了表明通量的复杂模式，该通量可能受环境条件下与强diel模式相关的物理或生物过程驱动的反硝化和消耗的N ₂产量平衡所控制。我们调查了模型拟合对与添加N ₂有关的观察数据的潜在改进消耗术语代表与白天光合作用相关的生物（N ₂固着）或物理（气泡形成和N ₂清除）机制。我们还将当前的单站diel通量模型扩展为两站模型，以估算离散河段的反硝化作用。我们改进的diel N ₂通量模型在三个指标（纳什-萨特克利夫效率，均方根比和偏差百分比）上显着改善了模型拟合，从而提高了它们在浅层，开放式雨棚，抽水系统中的效用。虽然需要更多的研究来了解与N ₂相关的具体机制小型农业排水系统的消耗过程以及影响其相对重要性的环境条件，这些结果改善了N ₂通量的估算，其中动态条件和生境的异质性在控制溶解气体浓度的因素中形成了严重的diel模式，并禁止使用N ₂通量的准确估算现有模型。