Impacts of fertilization regimes on soil heterotrophic respiration of purple soil

Recent studies have shown that soil respiration is the critical importance in determining the carbon balance of terrestrial ecosystems. Respiration from soils is comprised of both the heterotrophic respiration of microorganisms (soil. bacteria, fungi, and fauna) and autotrophic respiration from roots and mycorrhizae. Precise assessment of these components is important for calculating the carbon budgets of vegetation and the turnover rate of soil organic matter, as well as for understanding sources and sinks of carbon in terrestrial ecosystems in the face of global climate change. The results showed that temperature sensitivity (Q[sub 10]) values in wheat season always higher than that in maize season at all plots. During the whole experiment time, the magnitudes of Q[sub 10] both followed the order of OM > NPK > RSDNPK, which was clearly reflected that Q[sub 10] was sensitive to lower C/N organic materials. It indicated that the Q[sub 10] values for soil heterotrophic respiration rates were higher at lower temperatures and lower at higher temperature.