文献类型： 外文期刊

作者： Zhang, Weijun ¹ ; Munkholm, Lars J. ² ; An, Tingting ¹ ; Liu, Xu ¹ ; Zhang, Bin ³ ; Xu, Yingde ¹ ; Ge, Zhuang ¹ ; Zhang, Yan ¹ ; Zhang, Jiuming ⁴ ; Li, Shuangyi ¹ ; Wang, Jingkuan ¹ ;

作者机构： 1.Shenyang Agr Univ, Coll Land & Environm, Northeast Key Lab Conservat & Improvement Cultiva, Minist Agr & Rural Affairs, Shenyang 110866, Peoples R China

2.Aarhus Univ, Dept Agroecol, POB 50, DK-8830 Tjele, Denmark

3.Nanjing Univ Informat Sci & Technol, Sch Appl Meteorol, Nanjing 210044, Peoples R China

4.Heilongjiang Acad Agr Sci, Inst Soil Fertilizer & Environm Resources, Harbin 150086, Heilongjiang, Peoples R China

关键词： Soil organic carbon; Environmental factors; Soil layers; Maize cropland; Mollisol

期刊名称：SCIENCE OF THE TOTAL ENVIRONMENT （ 影响因子：10.753； 五年影响因子：10.237 ）

ISSN： 0048-9697

年卷期： 2022 年 835 卷

页码：

收录情况： SCI

摘要： The Mollisol region of Northeast China has a large soil organic carbon (SOC) storage which is important for maintain-ing soil fertility. SOC is susceptible to various environmental factors; however, the responses of SOC content to envi-ronmental factors in different soil layers of cropland remain unclear, particularly in deep soil layers. In this study, we collected 138 soil samples from the surface, subsurface, and subsoil layers among 46 sample sites with monocropping maize and intensive conventional tillage in this region. We assessed the relative importance and effect paths of 12 environmental factors (including geography, climate, and soil properties) on SOC content in different layers using redundancy analysis (RDA), structural equation model (SEM), and variation partitioning analysis (VPA). The VPA results showed that SOC content was mainly affected by climatic factors that explained 68% and 57% for the surface and subsurface layers, respectively. However, SOC content in the subsoil layer was greatly affected by soil properties that explained 27%. Furthermore, the SEMs results suggested that geographical factors indirectly af-fected SOC content by influencing the climatic factors. Mean annual temperature was the most important factor affect-ing SOC content directly or indirectly, and its negative effects significantly diminished with soil depth, as it explained 63%, 52%, and 17% of the variation in SOC content for the surface, subsurface and subsoil layers, respectively. In ad-dition, the effects of soil water-holding capacity on SOC content also decreased with soil depth, whereas pH and clay content showed a contrasting pattern. This implies that pH and clay content play important roles in the sequestration of SOC in deep soil layers. Moreover, the organic C content within >53 mu m aggregates was more sensitive to environmental factors. This study can be useful for forecasting SOC dynamics and establishing reasonable C management strategies under climate change conditions.