The temperature sensitivity of soil organic carbon decomposition is greater in subsoil than in topsoil during laboratory incubation.

ABSTRACT: The turnover of soil organic carbon (SOC) in cropland plays an important role in terrestrial carbon cycling, but little is known about the temperature sensitivity (Q ₁₀) of SOC decomposition below the topsoil layer of arable soil. Here, samples of topsoil (0-20 cm) and subsoil (20-40 cm) layers were obtained from paddy fields and upland croplands in two regions of China. Using a sequential temperature changing method, soil respiration rates were calculated at different temperatures (8 °C to 28 °C) and fitted to an exponential equation to estimate Q ₁₀ values. The average SOC decomposition rate was 59% to 282% higher in the topsoil than in the subsoil layer because of higher labile carbon levels in the topsoil. However, Q ₁₀ values in the topsoil layer (5.29

SUBMITTER: Yan D 

PROVIDER: S-EPMC5507886 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature