Relationships between leaf delta N-15 and leaf metallic nutrients

文献类型： 外文期刊

第一作者： Chen, Chongjuan

作者： Chen, Chongjuan;Wu, Yingjie;Liu, Zhaotong;Wang, Guoan;Chen, Chongjuan;Wang, Shuhan

作者机构：

期刊名称：RAPID COMMUNICATIONS IN MASS SPECTROMETRY （ 影响因子：2.419； 五年影响因子：2.439 ）

ISSN： 0951-4198

年卷期： 2021 年 35 卷 2 期

页码：

收录情况： SCI

摘要： Rationale Nitrogen (N) isotopic ratios (delta N-15 values) of plants are primarily determined by the delta N-15 values of their N sources. Metallic nutrients affect plant N uptake. However, there is little knowledge of the relationships between leaf delta N-15 values and leaf metallic nutrients. The delta N-15 values are often lower in soil nitrate (NO3-) than in ammonium (NH4+) due to large isotopic fractionation during nitrification. Plants acquire more NO3- than NH4+ when accumulating high potassium (K), calcium (Ca) and magnesium (Mg) to maintain charge balance. In addition, plants that absorb more NO3- than NH4+ increase the soil pH and decrease the availability of iron (Fe), manganese (Mn) and zinc (Zn). We therefore hypothesized that leaf delta N-15 values correlate negatively with K, Ca and Mg contents, while positively with Fe, Mn and Zn contents. Methods Leaves of non-N-fixing plants were sampled across an approx. 6000 km transect in China and their delta N-15 values and metallic nutrient content were determined using elemental analyzer/isotope ratio mass spectrometry. Results Inconsistent with the hypothesis, leaf delta N-15 values correlated positively with leaf K, Ca and Mg, indicating higher delta N-15 values of soil NO3- than NH4+. Higher delta N-15 values of soil NO3- revealed stronger denitrification than nitrification in the study regions because isotopic fractionation occurs during both processes. Leaf delta N-15 values correlated negatively with Fe, relating to decreases in soil Fe availability, which might be attributed to oxidation of Fe2+ to Fe3+ supplying electrons for denitrification, while greater uptake of NO3- than NH4+ of plants increases soil pH. Leaf delta N-15 values correlated positively with Zn and did not correlate with Mn. These observed relationships between leaf delta N-15 values and metallic nutrients, except Mn, were independent of vegetation or soil types. Conclusions This study has enriched our knowledge of associations between metallic nutrients and N cycling in plant-soil systems, especially for the roles of Fe in soil N transformations and K, Ca and Mg in plant N uptake.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序