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Aims <p>Livestock dung, an important nitrogen (N) source in alpine grasslands, plays a key role in N dynamics and nitrous oxide (N<sub>2</sub>O) emissions from grassland ecosystems. This study aimed to explore the differential effects of dung addition on soil N transformation and N<sub>2</sub>O emissions in alpine grasslands.</p> Methods <p>A 21-day indoor incubation experiment was conducted to investigate the effects of yak (<i>Bos grunniens</i>) dung (YD) and Tibetan sheep (<i>Ovis aries</i>) dung (TSD) addition on gross N transformation rates in an alpine meadow and explore the gross and net N transformation rates and their relationship with soil N<sub>2</sub>O emissions.</p> Results <p>YD and TSD addition promoted cumulative soil N mineralization and ammonium (NH<sub>4</sub><sup>+</sup>) immobilization increased by 36.9%–59.7% and 44.6%–89.0%, respectively. The average ratio of rates of gross N mineralization rate to gross NH<sub>4</sub><sup>+</sup> immobilization (<i>m</i>:<i>ia</i>) was lower in the YD and TSD treatments than the control. Dung addition improved the balance between soil N immobilization and mineralization, with the TSD treatment achieving better N retention and reducing the risk of N loss. Cumulative soil N<sub>2</sub>O emission for YD treatment was significantly greater than the TSD treatment, and the emissions in YD and TSD treatments were significantly and positively correlated with soil ammonium-N (NH<sub>4</sub><sup>+</sup>-N), total N (TN), and net nitrification rate (<i>NNR</i>), demonstrating dung addition increased soil N<sub>2</sub>O emissions by enhancing soil NH<sub>4</sub><sup>+</sup>-N and potential <i>NNR</i>. Denitrification and nitrification respectively dominated dung-treated soil N<sub>2</sub>O emissions during the first and later experimental stages.</p> Conclusions <p>The results indicate the significant contribution of nitrification to N<sub>2</sub>O emissions associated with dung addition and provides new insights into N balance and N<sub>2</sub>O emission mechanisms in alpine grasslands of pastoral areas. Tibetan sheep dung addition benefit for increasing alpine meadow N retention and reducing N loss compared to yak dung, and we suggest to appropriately increase the proportion of Tibetan sheep in the herd composition and advocate Tibetan sheep dung as a dominant strategy to maintain soil N sequestration and reduce N<sub>2</sub>O emissions in alpine meadow ecosystem. The conclusion helps to deepen the theoretical cognition in alpine grassland N transformation affected by livestock dung N input and provide scientific guidance for optimizing livestock dung management practices.</p>

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Yak dung generates lower soil N retention and stimulates higher N2O emissions relative to Tibetan sheep dung in an alpine meadow on the Eastern Qinghai-Tibetan Plateau

  • 期刊论文

  • 发表日期：

    2026年1月23日

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  • Zhaoyang Xiong,
  • Xiaodan Wang,
  • Yanjiang Cai,
  • Da Wei,
  • Jian Sun,
  • Jiangtao Hong,
  • Yongheng Gao,
  • Xue Zhang,
  • Ying Cao,
  • Huan Qian,
  • Yaxian Guo,
  • Ziyin Du

摘要

Aims

Livestock dung, an important nitrogen (N) source in alpine grasslands, plays a key role in N dynamics and nitrous oxide (N2O) emissions from grassland ecosystems. This study aimed to explore the differential effects of dung addition on soil N transformation and N2O emissions in alpine grasslands.

Methods

A 21-day indoor incubation experiment was conducted to investigate the effects of yak (Bos grunniens) dung (YD) and Tibetan sheep (Ovis aries) dung (TSD) addition on gross N transformation rates in an alpine meadow and explore the gross and net N transformation rates and their relationship with soil N2O emissions.

Results

YD and TSD addition promoted cumulative soil N mineralization and ammonium (NH4+) immobilization increased by 36.9%–59.7% and 44.6%–89.0%, respectively. The average ratio of rates of gross N mineralization rate to gross NH4+ immobilization (m:ia) was lower in the YD and TSD treatments than the control. Dung addition improved the balance between soil N immobilization and mineralization, with the TSD treatment achieving better N retention and reducing the risk of N loss. Cumulative soil N2O emission for YD treatment was significantly greater than the TSD treatment, and the emissions in YD and TSD treatments were significantly and positively correlated with soil ammonium-N (NH4+-N), total N (TN), and net nitrification rate (NNR), demonstrating dung addition increased soil N2O emissions by enhancing soil NH4+-N and potential NNR. Denitrification and nitrification respectively dominated dung-treated soil N2O emissions during the first and later experimental stages.

Conclusions

The results indicate the significant contribution of nitrification to N2O emissions associated with dung addition and provides new insights into N balance and N2O emission mechanisms in alpine grasslands of pastoral areas. Tibetan sheep dung addition benefit for increasing alpine meadow N retention and reducing N loss compared to yak dung, and we suggest to appropriately increase the proportion of Tibetan sheep in the herd composition and advocate Tibetan sheep dung as a dominant strategy to maintain soil N sequestration and reduce N2O emissions in alpine meadow ecosystem. The conclusion helps to deepen the theoretical cognition in alpine grassland N transformation affected by livestock dung N input and provide scientific guidance for optimizing livestock dung management practices.