Temperature sensitivity (Q10) of stable, primed and easily available organic matter pools during decomposition in paddy soil

The response of stable and labile C pools to global warming is uncertain, especially in paddy soils with very low oxygen availability and the dominance of electron acceptors with low efficiency. To clarify the response of organic matter decomposition to warming, flooded paddy soil was incubated at four temperatures (5, 15, 25, and 35 °C) for 75 days. The 13C-labelled Na-acetate was used as an analogue for root exudates and as a methane (CH4) source. Soil with acetate had higher C availability to microorganisms leading to 2–2.7 times and 2–153 times higher emission of carbon dioxide (CO2) and CH4 on day 75 than from soil without acetate, respectively. Incubation temperature explained >40% of the variance of CO2 and CH4 effluxes. Acetate stimulated microbial activities and turnover and so, increased soil organic matter (SOM) mineralisation in the first week, especially at low temperatures (<15 °C) with slow acetate consumption and longer oxygen (O2) availability. The priming effects measured as CH4 emissions were especially sensitive to temperatures from 5 to 15 °C. The high Q10 value of primed CH4 (Q10 > 10) at low temperature indicates that flooded paddy fields will contribute greatly to the greenhouse effect in warm winters, which have become common from 1970s. Caution is necessary for interpretations of previous estimates of the temperature sensitivity of SOM decomposition because the priming effect was ignored, especially that of CH4 under the condition of limited O2 availability in paddy and other wetland soils.

Wei L.1, 2 , Zhu Z.1 , Liu S.1 , Xiao M.1 , Wang J. 1, 3 , Wu J.1, 2 , Ge T. 1, 7 , Deng Y.4 , Kuzyakov Y. 5, 6
Elsevier B.V.
  • 1 Changsha Research Station for Agricultural and Environmental Monitoring &amp; Key Laboratory of Agro-ecological Processes in Subtropical Region|Institute of Subtropical Agriculture|Chinese Academy of Sciences
  • 2 University of Chinese Academy of Sciences
  • 3 School of Environment|Natural Resources &amp; Geography|Bangor University
  • 4 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
  • 5 School of Resources and Environmental Engineering|Jiangxi University of Science and Technology
  • 6 Department of Soil Science of Temperate Ecosystems|University of Göttingen
  • 7 Agro-Technological Institute|RUDN University
Ключевые слова
Acetate addition; enzyme activity; paddy soil; priming effect; substrate availability; temperature sensitivity
Дата создания
Дата изменения
Постоянная ссылка

Другие записи

Кононов А.А., Гришин В.Н., Авдотьин В.П., Авдотьина М.В.
Гражданская оборона на страже мира и безопасности. Академия Государственной противопожарной службы Министерства Российской Федерации по делам гражданской обороны, чрезвычайным ситуациям и ликвидации последствий стихийных бедствий. 2021. С. 247-253