Scholarlink

Background <p>Securing high vegetable yields while mitigating environmental risks remains a critical challenge in subtropical plateau agroecosystems, particularly in the Erhai Lake Basin of China.</p> Methods <p>A 17-year field experiment was conducted with six treatments: no fertilization (CK), conventional fertilization (CON), organic manure alone (OM), combined organic–inorganic fertilization (NPK + OM), and NPK + OM with extra N (NPK + OM+N) or extra P (NPK + OM+P) We evaluated yield stability, soil N/P dynamics and losses, P mineral forms (XRD), heavy metal accumulation, and yield drivers via random forest and PLS-PM.</p> Results <p>OM achieved the highest and most stable yield (CV 7.09%), with cumulative N balance (245.48&#xa0;kg ha<sup>− 1</sup>) significantly lower than CON (727.06&#xa0;kg ha<sup>− 1</sup>, <i>p</i> &lt; 0.05) and cumulative P balance (624.29&#xa0;kg ha<sup>− 1</sup>) comparable to CON. XRD revealed that most accumulated P in OM-treated soil was bound with Fe and Zn into stable minerals (Fe<sub>2</sub>(PO<sub>4</sub>)OH, Zn<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>). However, OM also caused excessive Olsen-P (171.32&#xa0;mg kg<sup>− 1</sup>) and runoff dissolved P (1.31 mg L<sup>− 1</sup>), exceeding environmental thresholds. Random forest identified cumulative N balance as the key yield driver (optimal range 300–400&#xa0;kg ha<sup>− 1</sup>); OM fell slightly below this range, whereas CON and NPK + OM+N exceeded it. PLS-PM indicated that nutrient accumulation positively associated with yield (0.36) but also increased runoff losses, while heavy metals showed a negative association (− 0.37). Heavy metals remained below safety thresholds after 17 years, but progressive accumulation in OM and CON signals long-term risk.</p> Conclusions <p>Long-term exclusive organic fertilization achieves high yield and N efficiency but causes P saturation and elevated dissolved P runoff, posing a high non-point source pollution risk. Sole organic fertilization is not recommended in the Erhai Lake Basin; optimizing combined fertilization with a higher organic N proportion is needed to balance productivity and environmental risk.</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

Long-term exclusive organic fertilization sustains high vegetable yield but increases phosphorus saturation and dissolved P runoff risk in the Erhai Lake Basin

  • 期刊论文

  • 发表日期：

    2026年7月29日

查看全文
  • Changxin Liang,
  • Bo Fan,
  • Ibadullah Jan,
  • Baokun Lei,
  • Yongbo Xu

摘要

Background

Securing high vegetable yields while mitigating environmental risks remains a critical challenge in subtropical plateau agroecosystems, particularly in the Erhai Lake Basin of China.

Methods

A 17-year field experiment was conducted with six treatments: no fertilization (CK), conventional fertilization (CON), organic manure alone (OM), combined organic–inorganic fertilization (NPK + OM), and NPK + OM with extra N (NPK + OM+N) or extra P (NPK + OM+P) We evaluated yield stability, soil N/P dynamics and losses, P mineral forms (XRD), heavy metal accumulation, and yield drivers via random forest and PLS-PM.

Results

OM achieved the highest and most stable yield (CV 7.09%), with cumulative N balance (245.48 kg ha− 1) significantly lower than CON (727.06 kg ha− 1, p < 0.05) and cumulative P balance (624.29 kg ha− 1) comparable to CON. XRD revealed that most accumulated P in OM-treated soil was bound with Fe and Zn into stable minerals (Fe2(PO4)OH, Zn3(PO4)2). However, OM also caused excessive Olsen-P (171.32 mg kg− 1) and runoff dissolved P (1.31 mg L− 1), exceeding environmental thresholds. Random forest identified cumulative N balance as the key yield driver (optimal range 300–400 kg ha− 1); OM fell slightly below this range, whereas CON and NPK + OM+N exceeded it. PLS-PM indicated that nutrient accumulation positively associated with yield (0.36) but also increased runoff losses, while heavy metals showed a negative association (− 0.37). Heavy metals remained below safety thresholds after 17 years, but progressive accumulation in OM and CON signals long-term risk.

Conclusions

Long-term exclusive organic fertilization achieves high yield and N efficiency but causes P saturation and elevated dissolved P runoff, posing a high non-point source pollution risk. Sole organic fertilization is not recommended in the Erhai Lake Basin; optimizing combined fertilization with a higher organic N proportion is needed to balance productivity and environmental risk.