Scholarlink

<p>Water and nitrogen are two key factors regulating the growth, development, and quality of sweetpotato. Accurate diagnosis of nitrogen nutrition in sweetpotato under different water conditions is essential for improving yield and quality. In this study, three experiments were conducted over three years using two sweetpotato cultivars, Xinxiang and Yanshu 25, under five irrigation levels (W1–W5) and four nitrogen application rates (N0–N3). Plant biomass and nitrogen content were periodically measured at designated sampling dates. Bayesian hierarchical modeling was applied to establish critical nitrogen concentration (Nc) models for shoot and root of sweetpotato under different water conditions, with independent datasets used for validation. When irrigation exceeded 60% of field water capacity (θf), the critical shoot nitrogen concentration showed no significant differences among different water treatments, allowing the development of a generalized aboveground model: Nc = 3.8396DM⁻<sup>0.299</sup>. Similarly, the critical root nitrogen concentration curves showed no significant differences among different water treatments, resulting in a generalized underground model: Nc = 0.8523DM⁻<sup>0.185</sup>. The nitrogen nutrition index (NNI) increased with nitrogen application rate but decreased as the growing season advanced, whereas root dry matter accumulation exhibited an initial increase followed by a decline. Water–nitrogen interaction modeling indicated that both irrigation and nitrogen application significantly improved yield, with nitrogen having a more substantial effect. The highest yields were achieved at irrigation levels of 66.23% and 77.49% field capacity combined with nitrogen applications of 95.48&#xa0;kg ha⁻¹ and 80.05&#xa0;kg ha⁻¹ for Xinxiang and Yanshu 25, respectively. This study delineates shifts in critical nitrogen concentration under varying irrigation levels, providing a robust basis for precision water and nitrogen management in sweetpotato production systems.</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

Nitrogen nutrition diagnosis of sweetpotato based on critical nitrogen dilution curve under different water conditions

  • 期刊论文

  • 发表日期：

    2026年7月17日

查看全文
  • Xu Zhao,
  • Ximing Xu,
  • Jing Yu,
  • Minghuan Jin,
  • Siyu Wang,
  • Yueming Zhu,
  • Guoquan Lu,
  • Zunfu Lv

摘要

Water and nitrogen are two key factors regulating the growth, development, and quality of sweetpotato. Accurate diagnosis of nitrogen nutrition in sweetpotato under different water conditions is essential for improving yield and quality. In this study, three experiments were conducted over three years using two sweetpotato cultivars, Xinxiang and Yanshu 25, under five irrigation levels (W1–W5) and four nitrogen application rates (N0–N3). Plant biomass and nitrogen content were periodically measured at designated sampling dates. Bayesian hierarchical modeling was applied to establish critical nitrogen concentration (Nc) models for shoot and root of sweetpotato under different water conditions, with independent datasets used for validation. When irrigation exceeded 60% of field water capacity (θf), the critical shoot nitrogen concentration showed no significant differences among different water treatments, allowing the development of a generalized aboveground model: Nc = 3.8396DM⁻0.299. Similarly, the critical root nitrogen concentration curves showed no significant differences among different water treatments, resulting in a generalized underground model: Nc = 0.8523DM⁻0.185. The nitrogen nutrition index (NNI) increased with nitrogen application rate but decreased as the growing season advanced, whereas root dry matter accumulation exhibited an initial increase followed by a decline. Water–nitrogen interaction modeling indicated that both irrigation and nitrogen application significantly improved yield, with nitrogen having a more substantial effect. The highest yields were achieved at irrigation levels of 66.23% and 77.49% field capacity combined with nitrogen applications of 95.48 kg ha⁻¹ and 80.05 kg ha⁻¹ for Xinxiang and Yanshu 25, respectively. This study delineates shifts in critical nitrogen concentration under varying irrigation levels, providing a robust basis for precision water and nitrogen management in sweetpotato production systems.