Contribution of winter soil respiration to annual soil CO2 emission in a Mollisol under different tillage practices in northeast China

• Published in: Global biogeochemical cycles Vol. 26; no. 2
• Main Authors: Shi, Xiuhuan, Zhang, Xiaoping, Yang, Xueming, Drury, Craig F., McLaughlin, Neil B., Liang, Aizhen, Fan, Ruqin, Jia, Shuxia
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.06.2012; American Geophysical Union
• Subjects: Agricultural land; Agriculture; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; black soil; Carbon; Carbon dioxide emissions; Climate change; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fluctuations; Fundamental and applied biological sciences. Psychology; General aspects; Geobiology; Geochemistry; Growing season; non-growing season; northeast China; Q10; Respiration; Soil sciences; soil temperature; Soils; Synecology; Systems science; Tillage; Winter; winter soil CO2 flux; Asia; Europe; China; Southern Europe; Italy; Marches Italy; Far East; atmosphere; Cultivated field; carbon; Carbon dioxide; ecosystems; Growing season; respiration; soils; seasonal variations; tillage
• ISSN: 0886-6236; 1944-9224
• DOI: 10.1029/2011GB004054

Winter soil CO2 emission is a very important component of the annual carbon budgets, however, almost no information on winter CO2 emission is available from the cropland soil in northeast China. In this study, soil CO2flux was measured for a 2‐year period from an ongoing tillage trial on Black soil in northeast China to quantify seasonal patterns in soil CO2 flux rate and wintertime contribution to annual soil respiration. Average soil CO2 flux rates in the winter (November to March) were between 0.64 to 1.22 g CO2 m−2 d−1, in the non‐growing season (October and April) were 2.09–3.56 g CO2 m−2 d−1, whereas in the growing season (May to September) they were between 10.9 to 12.7 g CO2 m−2 d−1, with no significant differences among tillage treatments. Total winter, non‐growing and growing season soil CO2 emissions were 0.28–0.45 Mg C ha−1, 0.36–0.53 Mg C ha−1, and 4.52–5.55 Mg C ha−1, respectively, among tillage treatments. The contributions of winter soil respiration to annual soil CO2emission ranged from 5.1 to 7.1%, and the non‐growing season emission ranged from 11.4 to 15.2% among tillage treatments. Our results indicate that in northeast China, cropland Black soil continuously emits CO2throughout the non‐growing season, and the wintertime soil respiration plays a significant role in annual soil carbon budgets. Hence winter soil CO2 emission must be taken into consideration when the role of the soil ecosystem is assessed as either a sink or source of CO2 to the atmosphere. Key Points Black soil continuously emits CO2 throughout the winter in northeast China Winter soil respiration plays a significant role in annual soil carbon budgets