Soil calcium constrains nitrogen mineralization and nitrification rates in subtropical karst regions

文献类型: 外文期刊

第一作者: Yang, Shuting

作者: Yang, Shuting;Yang, Lin;Liu, Lijun;Cao, Jianhua;Zhu, Tongbin;Yang, Shuting;Yang, Lin;Cao, Jianhua;Zhu, Tongbin;Wen, Dongni;Ni, Kang;Zhu, Tongbin;Mueller, Christoph;Mueller, Christoph;Mueller, Christoph;Mueller, Christoph;Zhu, Tongbin

作者机构:

关键词: Karst; Soil inorganic N; Mineralization; Nitrification; Calcium

期刊名称:SOIL BIOLOGY & BIOCHEMISTRY ( 影响因子:9.7; 五年影响因子:10.2 )

ISSN: 0038-0717

年卷期: 2023 年 186 卷

页码:

收录情况: SCI

摘要: Inorganic nitrogen (N) is the most important nutrient in soils, because it limits plant productivity and affects ecosystem function. It is produced by the mineralization of organic N to ammonium (NH4+) (M-Norg) and the subsequent nitrification of NH4+ to nitrate (NO3-) (O-NH4). Previous studies systematically evaluated the patterns and mechanisms of M-Norg and O-NH4 in soils on a global scale, but the characteristics of both processes in karst regions remain largely unknown. We conducted a(15)N-tracing study to investigate the rates of M-Norg and O-NH4, and the factors that influence these processes, from different natural ecosystems (mainly grass, shrub and forest) within karst regions. The rates of both M-Norg and O-NH4 exhibited large spatial variations, ranging from 0.42 to 23.8 mg N kg(-1) d(-1) and from 0.23 to 29.1 mg N kg(-1) d(-1), respectively, which were mainly ascribed to the heterogeneity of soil nutrients in karst regions. The concentrations of SOC, TN, soil inorganic N, NO3-, total K, Ca, Mg, WHC, and the rates of M-Norg and O-NH4 ranked as grass < shrub < forest, indicating that the improvement of soil conditions could stimulate the inorganic N production along the vegetation succession. The relative importance of the explanatory variables for inorganic N production suggested that the soil calcium concentration was the predominant determinant of the rates of M-Norg and O-NH4 in karst regions. A structural equation model indicated that soil calcium stimulates organic N accumulation, by serving as the substrate driving the increased rates of M-Norg and O-NH4 under high pH conditions. Overall, our results highlight the importance of soil calcium in determining the rates of M-Norg and O-NH4 in karst regions.

分类号:

  • 相关文献
作者其他论文 更多>>