Comparing carbon and nitrogen stocks in paddy and upland soils: Accumulation, stabilization mechanisms, and environmental drivers

Paddy soils, a type of Hydragric Anthrosol, have much greater soil organic C (SOC) and total N (TN) contents than that in upland soils. However, this fact has never been generalized or mechanistically explained. We conducted a global meta-analysis on the organic C and total N contents and their stocks in continuous paddy soils (578 sites) and compared them with those in adjacent upland soils. Average C stocks up to depths of 35 cm in upland and paddy soils were 31 and 47 Mg C ha−1, respectively. The N stocks in upland and paddy soils were 2.2 and 3.2 Mg N ha−1, respectively. The combined effects of mean annual temperature and precipitation showed that C and N stocks in paddy and upland soils are generally the largest under cool and humid conditions and the smallest in warm and dry climates. Quantitative analysis of climatic, and soil physical and chemical factors showed that 1) climate effects are weakened by management such as puddling and flooding, thereby increasing the importance of soil physico-chemical properties, which control soil organic matter (SOM) stabilization, and 2) climate (e.g., mean annual precipitation) mainly affects C and N stocks in upland soils; the chemical properties (such as pH), on the other hand, primarily affect C and N stocks in paddy soils. Greater C and N stocks in paddy soils are the result of 1) a larger input of organic C by rice than by most upland cereals, 2) slower decomposition of plant residues and SOM under anoxic conditions, and 3) a greater importance of sesquioxides in the biochemical stabilization of SOM. We conclude that these man-made paddy soils store more organic C and N than their upland neighbors despite long-term and intensive management. © 2021 Elsevier B.V.

Wei L.1, 2 , Ge T.1, 3 , Zhu Z.1 , Luo Y.4 , Yang Y.5 , Xiao M.1 , Yan Z.6 , Li Y. 1 , Wu J.1, 2 , Kuzyakov Y. 1, 7, 8
  • 1 Key Laboratory of Agro-ecological Processes in Subtropical Region & Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
  • 2 University of Chinese Academy of Sciences, Beijing, 100049, China
  • 3 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, 315211, China
  • 4 Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
  • 5 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
  • 6 Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University
  • 7 Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Goettingen, Goettingen, 37077, Germany
  • 8 Agro-Technological Institute, RUDN University, Moscow, 117198, Russian Federation
C and N stocks; Carbon sequestration; Land-use change; Microbial turnover; Paddy soils; Upland soils
Date of creation
Date of change
Short link

Other records