Scholarlink

<p>Soil nitrogen (N) mineralization and nitrification play critical roles in global N cycling. However, their responses to environmental variables (temperature and moisture) remain unexplored in paddy ecosystems. This study aimed to evaluate temperature sensitivity (Q<sub>10</sub>) of N mineralization and nitrification in paddy soil under aerobic condition and subsequent N mineralization under anaerobic condition. Paddy samples were aerobically incubated under four temperature (± 5, 5, 15, and 25&#xa0;°C) and two moisture (60% and 100% water-filled pore space (WFPS)) conditions for 24&#xa0;weeks. The&#xa0;± 5&#xa0;°C was designed to simulate the diurnal variation of soil temperature between night-time (–5&#xa0;°C, 12&#xa0;h) and day-time (5&#xa0;°C, 12&#xa0;h). Subsequently, all samples underwent anaerobic incubation at 30&#xa0;°C for 4&#xa0;weeks. Aerobic and anaerobic incubations simulated the off−rice and rice growing seasons, respectively. Elevated temperature significantly reduced total N (TN) content but increased stable N isotope (δ<sup>15</sup>N) values. Conversely, elevated soil moisture significantly increased δ<sup>15</sup>N values but not TN content. Soil temperature significantly promoted net aerobic N mineralization and nitrification evidenced by increased mineral N and nitrate N (NO<sub>3</sub><sup>−</sup>-N) levels. The Q<sub>10</sub> values of net aerobic N mineralization and nitrification were 0.30−3.81, and 1.08 −3.82, respectively. High moisture enhanced the Q<sub>10</sub> values of net aerobic N mineralization and nitrification at low temperatures (± 5−5&#xa0;°C), whereas low moisture promoted them at high temperatures (5−25&#xa0;°C), likely due to moisture-stimulated freeze−thaw cycle during aerobic incubation. Anaerobic N mineralization significantly decreased with previously increased temperature during aerobic incubation, suggesting that rising temperature during off−rice season promotes N mineralization, leading to decreased N mineralization for rice production. Elevated temperature has greater propensity to stimulate N mineralization and nitrification in paddy soils than elevated moisture, establishing positive feedback loops to increased N availability and loss under global warming.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Elevated Temperature has a more Stimulating Effect than Elevated Moisture on N Mineralization and Nitrification in a Paddy Soil of Japan

  • 期刊论文

  • 发表日期：

    2025年7月5日

查看全文
  • Shuirong Tang,
  • Xujiao Bao,
  • Lei Meng,
  • Xingkai Xu,
  • Lei Wu,
  • Keitaro Tawaraya,
  • Weiguo Cheng

摘要

Soil nitrogen (N) mineralization and nitrification play critical roles in global N cycling. However, their responses to environmental variables (temperature and moisture) remain unexplored in paddy ecosystems. This study aimed to evaluate temperature sensitivity (Q10) of N mineralization and nitrification in paddy soil under aerobic condition and subsequent N mineralization under anaerobic condition. Paddy samples were aerobically incubated under four temperature (± 5, 5, 15, and 25 °C) and two moisture (60% and 100% water-filled pore space (WFPS)) conditions for 24 weeks. The ± 5 °C was designed to simulate the diurnal variation of soil temperature between night-time (–5 °C, 12 h) and day-time (5 °C, 12 h). Subsequently, all samples underwent anaerobic incubation at 30 °C for 4 weeks. Aerobic and anaerobic incubations simulated the off−rice and rice growing seasons, respectively. Elevated temperature significantly reduced total N (TN) content but increased stable N isotope (δ15N) values. Conversely, elevated soil moisture significantly increased δ15N values but not TN content. Soil temperature significantly promoted net aerobic N mineralization and nitrification evidenced by increased mineral N and nitrate N (NO3−-N) levels. The Q10 values of net aerobic N mineralization and nitrification were 0.30−3.81, and 1.08 −3.82, respectively. High moisture enhanced the Q10 values of net aerobic N mineralization and nitrification at low temperatures (± 5−5 °C), whereas low moisture promoted them at high temperatures (5−25 °C), likely due to moisture-stimulated freeze−thaw cycle during aerobic incubation. Anaerobic N mineralization significantly decreased with previously increased temperature during aerobic incubation, suggesting that rising temperature during off−rice season promotes N mineralization, leading to decreased N mineralization for rice production. Elevated temperature has greater propensity to stimulate N mineralization and nitrification in paddy soils than elevated moisture, establishing positive feedback loops to increased N availability and loss under global warming.

Graphical Abstract