ABSTRACT Treatment with nitrification inhibitors, such as dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) have been strongly indicated to increase grassland biomass and mitigate soil N2O emission rates. However, the responses of both alpine meadow aboveground biomass and N2O emission rates to nitrification inhibitors remains unclear. We separately applied three doses of DCD and DMPP to alpine grassland soils with three duplicates. The biomass and N2O emission rates were subsequently measured by a clear-cut method and in-situ static chamber gas chromatography during the growing season. Our findings indicated that aboveground biomass increased significantly, and N2O emission rate decreased significantly at 6.8 kg ha−1 DCD and DMPP. Furthermore, the biomass increase effect was more significant than the N2O emission rate mitigation effect (p < 0.05). The highest ratios of DCD treatments on meadow production increase and N2O emission rate decrease were 27.2% and 36.3%, respectively. Our findings provide insight into the enhanced grassland primary production and decreased N2O flux by nitrification inhibitor treatment in alpine meadows, which may be beneficial to help mitigate global warming.

中文翻译：

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硝化抑制剂对青藏高原高寒草甸植物生物量和N2O排放速率的影响

摘要 用双氰胺 (DCD) 和 3,4-二甲基吡唑磷酸盐 (DMPP) 等硝化抑制剂处理已被强烈表明可以增加草地生物量并降低土壤 N2O 排放率。然而，高寒草甸地上生物量和 N2O 排放率对硝化抑制剂的反应仍不清楚。我们分别将三剂 DCD 和 DMPP 施用于高寒草地土壤，一式三份。随后在生长季节通过明确方法和原位静态室气相色谱法测量生物量和 N2O 排放率。我们的研究结果表明，在 6.8 kg ha-1 DCD 和 DMPP 时，地上生物量显着增加，N2O 排放率显着降低。此外，生物量增加效应比 N2O 排放率减缓效应更显着（p < 0.05）。DCD 处理对草甸产量增加和 N2O 排放率降低的最高比例分别为 27.2% 和 36.3%。我们的研究结果提供了对高寒草甸硝化抑制剂处理提高草地初级生产和降低 N2O 通量的见解，这可能有助于缓解全球变暖。