Response of soil organic carbon mineralization in typical Karst soils following the addition of 14C-labeled rice straw and CaCO3

Authors

  • Lening Hu,

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
    3. Huanjiang Observation and Research Station for Karst Eco-systems, Huanjiang 547100, China
    Search for more papers by this author
  • Yirong Su,

    Corresponding author
    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Huanjiang Observation and Research Station for Karst Eco-systems, Huanjiang 547100, China
    • Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
    Search for more papers by this author
  • Xunyang He,

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Huanjiang Observation and Research Station for Karst Eco-systems, Huanjiang 547100, China
    Search for more papers by this author
  • Jinshui Wu,

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    Search for more papers by this author
  • Hua Zheng,

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
    3. Huanjiang Observation and Research Station for Karst Eco-systems, Huanjiang 547100, China
    Search for more papers by this author
  • Yang Li,

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
    3. Huanjiang Observation and Research Station for Karst Eco-systems, Huanjiang 547100, China
    Search for more papers by this author
  • Aihua Wang

    1. Key Laboratory of Subtropical Agriculture Ecology, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
    2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
    Search for more papers by this author

Abstract

BACKGROUND: Organic substrates and calcium are important factors controlling organic matter turnover in Karst soils. To understand their effects on soil organic carbon (SOC) mineralization, an incubation experiment was conducted involving a control treatment (CK), the addition of a 14C-labeled rice straw (T1), CaCO3 (T2), and both 14C-labeled rice straw and CaCO3 (T3) to two types of Karst soils (terra fusca and rendzina) and a red soil from southwestern China.

RESULTS: Cumulative mineralization of the rice straw over 100 days in rendzina (22.96 mg kg−1) and terra fusca (23.19 mg kg−1) was higher than in the red soil (15.48 mg kg−1; P < 0.05). Cumulative mineralization of native SOC decreased following addition of 14C-labeled rice straw in the rendzina and terra fusca but increased in the red soil (negative and positive priming effects on native SOC). The turnover times of 14C-labeled microbial biomass C (MBC) in the red soil, terra fusca and rendzina were 71 ± 2, 243 ± 20 and 254 ± 45 days, respectively. By adding CaCO3, the accumulation of SOC was greater in the Karst soils than in the red soil.

CONCLUSION: Although the interactions between rice straw decomposition and priming effects on native SOC are not yet understood, there was considerable variation between Karst and red soils. Soil calcium was a positive factor in maintaining SOC stability. MBC from rice straws was stable in terra fusca and rendzina, whereas it was active in the red soil. The Karst soils (terra fusca and rendzina) used in this study benefited SOC accumulation. Copyright © 2011 Society of Chemical Industry

Ancillary