Scholarlink

<p>Soil carbon sequestration should mitigate climate change, yet the dynamics of deep soil carbon are poorly known. Here, we conducted a 12-year field experiment in a Fluvic Cambisol under a wheat–maize rotation system, comparing straw return with straw removal, and quantified carbon stocks across a 0–200&#xa0;cm soil profile. We traced carbon sources using both natural <sup>13</sup>C abundance, and <sup>13</sup>C-labeled glucose in a 60-day laboratory incubation experiment. Results show that straw return increased soil inorganic carbon stocks by 57.6 t ha<sup>−1</sup> in the 100–200&#xa0;cm layers. Pedogenic carbon increased by 96.6% in the 0–20&#xa0;cm topsoil and by 97.7% in the 120–140&#xa0;cm deep soil, whereas lithogenic carbon remained stable, indicating that soil inorganic carbon gains originated primarily from pedogenic carbonate formation. 72.23% of the added <sup>13</sup>C-glucose was mineralized to CO<sub>2</sub>, while 17.27% was transformed into soil inorganic carbon, suggesting that exogenous carbon reaching the 120–140&#xa0;cm soil layer can enhance pedogenic carbonate formation. Straw return increased microbial biomass carbon by 192% in topsoil and 144% in deep soil, and increased carbonic anhydrase activity by 43% and 73%, respectively. These findings reveal a previously overlooked, microbially-mediated mechanism for deep soil inorganic carbon accumulation, highlighting deep soil inorganic carbon as a stable carbon sink in alkaline croplands.</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

Deep soil inorganic carbon, an overlooked carbon sink in alkaline croplands

  • 期刊论文

  • 发表日期：

    2026年6月29日

查看全文
  • Yingjie Yin,
  • Jianying Shang,
  • Zhangliu Du,
  • Kesi Liu,
  • Bingzi Zhao,
  • Hongbo He,
  • Xudong Zhang,
  • Dan Wei,
  • Tusheng Ren,
  • Baoguo Li,
  • Chao Liang

摘要

Soil carbon sequestration should mitigate climate change, yet the dynamics of deep soil carbon are poorly known. Here, we conducted a 12-year field experiment in a Fluvic Cambisol under a wheat–maize rotation system, comparing straw return with straw removal, and quantified carbon stocks across a 0–200 cm soil profile. We traced carbon sources using both natural 13C abundance, and 13C-labeled glucose in a 60-day laboratory incubation experiment. Results show that straw return increased soil inorganic carbon stocks by 57.6 t ha−1 in the 100–200 cm layers. Pedogenic carbon increased by 96.6% in the 0–20 cm topsoil and by 97.7% in the 120–140 cm deep soil, whereas lithogenic carbon remained stable, indicating that soil inorganic carbon gains originated primarily from pedogenic carbonate formation. 72.23% of the added 13C-glucose was mineralized to CO2, while 17.27% was transformed into soil inorganic carbon, suggesting that exogenous carbon reaching the 120–140 cm soil layer can enhance pedogenic carbonate formation. Straw return increased microbial biomass carbon by 192% in topsoil and 144% in deep soil, and increased carbonic anhydrase activity by 43% and 73%, respectively. These findings reveal a previously overlooked, microbially-mediated mechanism for deep soil inorganic carbon accumulation, highlighting deep soil inorganic carbon as a stable carbon sink in alkaline croplands.