Scholarlink

<p>“Pre-rainfall topdressing” is a common practice in humid subtropical rainfed wheat systems. However, the impact of the interval between fertilization and subsequent rainfall on nitrogen losses, particularly N<sub>2</sub>O emissions and NH<sub>3</sub> volatilization, has not well quantified. This study therefore aimed to identify the optimal fertilization-rainfall interval for minimizing such losses in rainfed wheat fields.&#xa0;A simulated rainfall experiment was conducted with the following treatments: a no-precipitation control (NP) and precipitation treatments where rainfall occurred at 1 (P1), 3 (P3), 5 (P5), and 7 days (P7) after topdressing fertilization.&#xa0;Topdressing timing significantly influenced both N<sub>2</sub>O emissions and NH<sub>3</sub> volatilization. Compared with NP control, P3 and P5 treatments reduced NH<sub>3</sub> volatilization during the regreening fertilization stage (RS) by 34.22% and 14.55%, respectively, whereas P1 and P7 treatments increased it. During the jointing fertilization stage (JS), all precipitation treatments reduced NH<sub>3</sub> volatilization by 2.20%-24.02%, with P3 treatment exhibiting the greatest reduction. Furthermore, all precipitation treatments increased cumulative N<sub>2</sub>O emissions compared with NP control, by 3.04%-36.31% during RS and by 13.21%-89.92% during JS. Among precipitation treatments, P3 and P7 exhibited lower N<sub>2</sub>O emissions during RS, while P3 and P5 did so during JS. Correlation analysis revealed that soil moisture and pH were the dominant factors regulating N<sub>2</sub>O emissions, whereas NH<sub>3</sub> volatilization was jointly affected by soil NH<sub>4</sub><sup>+</sup>-N content, pH, and nitrate reductase activity.&#xa0;The fertilization-rainfall interval is key to regulating NH<sub>3</sub> volatilization and N<sub>2</sub>O emissions in rainfed wheat fields, with three days as the optimal pre-rainfall topdressing timing.</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

Optimizing Pre-Rainfall Nitrogen Topdressing Timing to Mitigate NH3 Volatilization and N2O Emissions in Rainfed Wheat Systems

  • 期刊论文

  • 发表日期：

    2026年5月12日

查看全文
  • Jing Wang,
  • Xiaofang Zhang,
  • Tianjia Hao,
  • Tingting Xu,
  • Bei Yang,
  • Pengfu Hou,
  • Lihong Xue,
  • Linzhang Yang

摘要

“Pre-rainfall topdressing” is a common practice in humid subtropical rainfed wheat systems. However, the impact of the interval between fertilization and subsequent rainfall on nitrogen losses, particularly N2O emissions and NH3 volatilization, has not well quantified. This study therefore aimed to identify the optimal fertilization-rainfall interval for minimizing such losses in rainfed wheat fields. A simulated rainfall experiment was conducted with the following treatments: a no-precipitation control (NP) and precipitation treatments where rainfall occurred at 1 (P1), 3 (P3), 5 (P5), and 7 days (P7) after topdressing fertilization. Topdressing timing significantly influenced both N2O emissions and NH3 volatilization. Compared with NP control, P3 and P5 treatments reduced NH3 volatilization during the regreening fertilization stage (RS) by 34.22% and 14.55%, respectively, whereas P1 and P7 treatments increased it. During the jointing fertilization stage (JS), all precipitation treatments reduced NH3 volatilization by 2.20%-24.02%, with P3 treatment exhibiting the greatest reduction. Furthermore, all precipitation treatments increased cumulative N2O emissions compared with NP control, by 3.04%-36.31% during RS and by 13.21%-89.92% during JS. Among precipitation treatments, P3 and P7 exhibited lower N2O emissions during RS, while P3 and P5 did so during JS. Correlation analysis revealed that soil moisture and pH were the dominant factors regulating N2O emissions, whereas NH3 volatilization was jointly affected by soil NH4+-N content, pH, and nitrate reductase activity. The fertilization-rainfall interval is key to regulating NH3 volatilization and N2O emissions in rainfed wheat fields, with three days as the optimal pre-rainfall topdressing timing.