Journal of Integrative Agriculture ›› 2022, Vol. 21 ›› Issue (5): 1475-1487.DOI: 10.1016/S2095-3119(21)63620-1

所属专题: 农业生态环境-有机碳与农业废弃物还田合辑Agro-ecosystem & Environment—SOC

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  • 收稿日期:2020-11-16 接受日期:2020-12-25 出版日期:2022-05-01 发布日期:2020-12-25

Estimation of soil organic carbon stock and its controlling factors in cropland of Yunnan Province, China

SUN Tao1, TONG Wen-jie2, CHANG Nai-jie3, DENG Ai-xing1, LIN Zhong-long4, FENG Xing-bing4, LI Jun-ying2, SONG Zhen-wei1   

  1. 1 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture and Rural Affairs, Beijing 100081, P.R.China
    2 Yunnan Academy of Tobacco Agricultural Sciences, Kunming 650021, P.R.China
    3 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    4 China Tobacco Company Yunnan Branch, Kunming 650011, P.R.China
  • Received:2020-11-16 Accepted:2020-12-25 Online:2022-05-01 Published:2020-12-25
  • About author:SUN Tao, E-mail: suntao1007@126.com; Correspondence SONG Zhen-wei, Tel: +86-10-62128815, E-mail: songzhenwei@caas.cn; LI Jun-ying, E-mail: ljy1250@163.com
  • Supported by:
    This research was funded by the Science and Technology Projects of Yunnan Province, China (2017YN06 and 2018BB019), the Key Research & Development project of Yunnan Province (2018530000241017), the National Natural Science Foundation of China (31671642).  

摘要:

基于分布于全省的8637个耕层(0-20 cm)土壤样品有机碳含量和土壤、气象以及农田分布等空间数据,本研究采用随机森林模型的方法绘制了云南省农田1 km分辨率的土壤有机碳分布图,并估算了土壤有机碳总储量。结果表明,云南省农田平均土壤有机碳密度和总储量分别为4.86 kg m-2和337.5 Mt。从空间分布来看,西北与东北地区的土壤有机碳密度相对较高。海拔高度、大气温度、年降水量以及地形湿度指数是影响土壤有机碳密度空间分布最主要的因素,其预测重要性指数分别达19.5%、17.3%、14.5%和9.9%。改善农田管理措施,如推广秸秆还田、优化肥料运筹等,可为提高作物产量、增加土壤固碳、实现云南省农田可持续生产提供有效保障


Abstract: Soil organic carbon (SOC) is the most important indicators of soil quality and health.  Identifying the spatial distribution of SOC and its influencing factors in cropland is crucial to understand the terrestrial carbon cycle and optimize agronomic management.  Yunnan Province, characterized by mountainous topography and varied elevation, is one of the highest SOC regions in China.  Yet its SOC stock of cropland and influencing factors has not been fully studied due to the lack of adequate soil investigation.  In this study, the digital mapping of SOC at 1 km resolution and the estimation of total SOC stock in cropland of Yunnan Province was undertaken using 8 637 topsoil (0–20 cm) samples and a series of spatial data through Random Forest (RF) model.  It was showed that across the cropland of Yunnan Province, the mean SOC density and total stock were 4.84 kg m–2 and 337.5 Mt, respectively.  The spatial distribution indicated that relatively high SOC density regions resided in the northwest and northeast parts of Yunnan Province.  Elevation (19.5%), temperature (17.3%), rainfall (14.5%), and Topographic wetness index (9.9%) were the most important factors which controlled spatial variability of SOC density.  Agronomic practices (e.g., crop straw treatments, fertilizer management) should be optimized for the sustainable development of crop production with high SOC sequestration capacity in Yunnan Province.

Key words: cultivated land , soil organic carbon ,  spatial distribution ,  driving factors ,  Random Forest