Acidic soils, occupying ca. 40% of the world's arable soils, often need to be managed (e.g., to raise their pH and to improve crop productivity); however, the environmental impact of raising soil pH is often difficult to assess. Increasing soil pH stimulates the reduction of N₂O to N₂, thus lowering N₂O emissions associated with denitrification, but can also increase autotrophic nitrification rates and related N₂O emission. Using a ¹⁵N tracing technique, we provide process‐based insights into the effects of two acid‐neutralizing materials (quicklime [CaO] vs. pig manure) on N₂O emissions in an acidified upland soil that had experienced excessive N application. Without pH adjustments we found that N₂O emissions, stimulated by supply of reactive N, were related to denitrification‐ and heterotrophic nitrification‐derived N₂O emissions, whereas autotrophic nitrification‐derived N₂O emissions declined with decreasing soil pH. These effects were reversed by increasing soil pH via liming. However, increasing the soil pH via application of pig manure significantly increased soil N₂O emissions from both nitrification and denitrification. Our study highlights that pH‐amelioration practices may enhance N₂O emissions depending on the type of material applied to the soil. Therefore, both pH remediation and greenhouse gas mitigation options need to be considered together to avoid adverse environmental effects. The effect of different acid‐neutralizing materials on soil N₂O emissions should be incorporated into ecosystem models to better estimate global N₂O emissions when pH amelioration is practised.

中文翻译：

---

不同pH升高材料对酸性旱地土壤N2O排放的影响

酸性土壤，约占。经常需要对世界40％的耕地进行管理（例如，提高土壤的pH值和提高农作物的生产力）；但是，提高土壤pH值对环境的影响通常很难评估。增加土壤的pH值可以刺激n的减少₂ O与N ₂，从而降低Ñ _2个脱硝有关的O排放，而且还可以增加自养硝化速率和相关的Ñ ₂ O排放。使用¹⁵ N示踪技术，我们提供了基于过程的洞察力，以了解两种酸中和材料（速溶钙[CaO]与猪粪）对N _{2的影响。}过量施用氮的酸化旱地土壤中的O排放。如果不进行pH调节，我们发现，由于反应性N的供应而刺激的N ₂ O排放与反硝化和异养硝化衍生的N ₂ O排放有关，而自养硝化衍生的N ₂ O排放随着土壤pH的降低而下降。通过撒石灰增加土壤pH可以逆转这些影响。然而，通过施用猪粪来增加土壤的pH值会显着增加硝化和反硝化过程中土壤N ₂ O的排放量。我们的研究强调，pH改善实践可能会增强N ₂O的排放量取决于施加到土壤的材料的类型。因此，必须同时考虑pH值修复和减少温室气体的选择，以避免不利的环境影响。在实施pH改善措施时，应将不同的酸中和物质对土壤N ₂ O排放的影响纳入生态系统模型，以更好地估算全球N ₂ O排放。