the National Natural Science Foundation of China（No. 42007097）, the Natural Science Foundation of Changsha City（No. kq2014184）and Natural Science Foundation of Hunan Province（S2021JJMSXM0179）
Objective Acetate is an important substrate for methane production, and its mineralization and transformation are key to the carbon cycle, carbon sequestration, and greenhouse gas mitigation in paddy soils. In long-term flooded paddy soils, iron, an important valence-variable metal, may influence the mineralization and transformation of acetate.Method Therefore, 13C-acetate, ferrihydrite and goethite were added into paddy soil and the CO2 and CH4 emissions were monitored. Also, the changes in paddy soil properties during anaerobic incubation (100 days) were analyzed. Additionally, we analyzed the characteristics of mineralization and transformation of acetate and its priming effect on CO2 and CH4 to reveal the roles of different types of iron oxides.Result The results showed that in the acetate treatment after incubation, 33% and 36% of acetate was mineralized to CH4 and CO2, respectively, while 0.12%, 2% and 28% were transformed to dissolved organic carbon (DOC), microbial biomass carbon (MBC) and soil organic carbon (SOC), respectively. Acetate caused a negative CO2 priming effect and a positive CH4 priming effect. The ratio of CO2 to CH4 sourced from soil organic carbon was changed from 3.46: 1 to 1.83: 1 by acetate addition. Goethite addition significantly increased acetate derived cumulative CO2 emission, while ferrihydrite showed no significant effect. Ferrihydrite and goethite significantly decreased SOC derived CO2 emission and strengthened the negative CO2 priming effect of acetate. Also, ferrihydrite and goethite significantly decreased acetate derived CH4 emission and showed no significant effect on SOC derived CH4 emission. The proportions of acetate transformed to MBC and SOC were significantly increased in the presence of ferrihydrite and goethite.Conclusion The mineralization and transformation of acetate influenced CO2 and CH4 emission from native SOC. Ferrihydrite and goethite, different in crystallinity, have different effects on mineralization, transformation and priming effect of acetate. Thus, this study can provide theoretical and technical support for carbon sequestration and greenhouse gas mitigation in paddy soils.
王云秋,李宇虹,祝贞科,吴金水,葛体达.铁氧化物对厌氧水稻土中乙酸矿化、转化及其激发效应的影响[J].土壤学报,2022,59(6):1683-1694. DOI:10.11766/trxb202105270277 WANG Yunqiu, LI Yuhong, ZHU Zhenke, WU Jinshui, GE Tida. The Effect of Iron Oxides on Mineralization, Transformation and Priming Effect of Acetate in Anoxic Paddy Soils[J]. Acta Pedologica Sinica,2022,59(6):1683-1694.复制