Dinitrogen emissions: an overlooked key component of the N balance of montane grasslands
Dinitrogen emissions: an overlooked key component of the N balance of montane grasslands
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DOI：
10.1007/s10533-019-00547-8
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发表时间：
2017-04
期刊：
影响因子：
4
通讯作者：
Marcus Zistl-Schlingmann;Jinchao Feng;R. Kiese;R. Stephan;Pablo Zuazo;G. Willibald;Changhui Wang
中科院分区：
文献类型：
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作者：
Marcus Zistl-Schlingmann;Jinchao Feng;R. Kiese;R. Stephan;Pablo Zuazo;G. Willibald;Changhui Wang
尽管草地土壤中一氧化氮（NO）、氨（NH3）和一氧化二氮（N2 O）的排放受到越来越多的限制，但对土壤中二氮（N2）的排放却知之甚少。然而，N2损失可能占总气态氮（N）损失的主导地位。氮损失的知识是发展适应气候的管理，平衡农艺和环境需求的关键。因此，我们量化了德国南部山地草原在环境气候条件和气候变化处理（+ 2 °C MAT，− 300 mm MAP）下的所有气态氮损失。对完整土芯的土壤N2排放量的月度测量显示，这些排放量远远超过土壤N2 O排放量，平均值为350 ± 101（环境气候）和738 ± 197 µg N m− 2 h −1（气候变化）。由于这些测量无法量化施肥后的排放峰值，因此部署了一个额外的实验室实验，以量化NH3，NO，N2 O和N2排放对典型泥浆施肥事件（51 kg N ha−1）的响应。我们的研究结果表明，总的N气体损失约为一半的应用浆料-N。N2的挥发损失占16-21 kg，占施用泥浆N的31-42%，NH3挥发损失（3.5 kg）、N2 O损失（0.2-0.5 kg）和NO损失（0-0.2 kg）的比例较小。虽然限制每年N2损失仍然不确定，由于高时空变化的通量，我们表明，N2损失是一个迄今为止被忽视的关键组成部分，氮平衡在山地草原，这需要考虑制定改进的草地管理策略，以提高氮的利用效率。
While emissions of nitric oxide (NO), ammonia (NH3) and nitrous oxide (N2O) from grassland soils have been increasingly well constrained, soil dinitrogen (N2) emissions are poorly understood. However, N2losses might dominate total gaseous nitrogen (N) losses. Knowledge on N losses is key for the development of climate-adapted management that balances agronomic and environmental needs. Hence, we quantified all gaseous N losses from a montane grassland in Southern Germany both for ambient climatic conditions and for a climate change treatment (+ 2 °C MAT, − 300 mm MAP). Monthly measurements of soil N2emissions of intact soil cores revealed that those exceeded by far soil N2O emissions and averaged at 350 ± 101 (ambient climate) and 738 ± 197 µg N m−2h−1(climate change). Because these measurements did not allow to quantify emission peaks after fertilization, an additional laboratory experiment was deployed to quantify the response of NH3, NO, N2O, and N2emissions in sub daily temporal resolution to a typical slurry fertilization event (51 kg N ha−1). Our results revealed that total N gas losses amounted to roughly half of applied slurry-N. Surprisingly, N2but not NH3dominated fertilizer N losses, with N2emissions accounting for 16–21 kg or 31–42% of the applied slurry-N, while NH3volatilization (3.5 kg), N2O (0.2–0.5 kg) and NO losses (0–0.2 kg) were of minor importance. Though constraining annual N2loss remained uncertain due to high spatiotemporal variability of fluxes, we show that N2losses are a so far overlooked key component of the N balance in montane grasslands, which needs to be considered for developing improved grassland management strategies targeted at increasing N use efficiency.