近10年典型区红壤性水稻土有机碳库平均驻留时间变化特征  

Variations of mean residence time of organic carbon pools in red paddy soil in a typical area in recent 10 years

作　　者：王玺洋 李晓晖[1,2] 辛在军 何石福[1,2] 孙小艳 李亮 WANG Xiyang;LI Xiaohui;XIN Zaijun;HE Shifu;SUN Xiaoyan;LI Liang(Institute of Microbiology,Jiangxi Academy of Sciences,Nanchang 330096,China;Jiangxi Institute of Watershed Ecology,Nanchang 330096,China)

机构地区：[1]江西省科学院微生物研究所,南昌330096 [2]江西省流域生态研究所,南昌330096

出　　处：《生态学杂志》2023年第3期561-568,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金(41867002);江西省重点研发项目(20202BBFL63048);江西省科学院重点研发项目(2020-YZD-27);国家红壤改良工程技术研究中心开放基金(2020NETRCRSI-3);中国科学院战略性先导科技专项资助项目(XDA05050507)资助。

摘　　要：弄清土壤有机碳库平均驻留时间的时空变化特征对采取有效措施增强农业生态系统碳“汇”尤为关键。本研究基于历史采样信息开展新一轮土壤样品采集,进行100 d土壤呼吸培养实验,借助三库一级动力学模型拟合获得土壤活性碳库(MRT_(a))和缓效性碳库平均驻留时间(MRT_(s)),揭示了2009—2019年江西东乡红壤性水稻土表层土壤MRT_(a)和MRT_(s)的时空变化特征及其影响因子。结果表明,东乡2019年红壤性水稻土表层土壤MRT_(a)与MRT_(s)均值分别为26.5 d和14.1 a,与2009年相比,未发生显著性变化。整体上,东乡南部地区活性碳库和缓效性碳库更为稳定,且东乡地区红壤性水稻土MRT_(a)与MRT_(s)存在明显的时空分异,不同地理位置的MRT_(a)与MRT_(s)变化幅度分别达-1.3%~544.5%和-6.7%~1375.5%。这种时空变异,部分源于土壤活性碳和缓效性碳组分构成的空间分异。尽管存在较大空间变异,与南方其他稻作区相比,东乡地区红壤性水稻土有机碳库近10年变得更为稳定。It is crucial to understand the spatiotemporal variations of mean residence time(MRT) of soil organic carbon(SOC) pool for taking effective measures to enhance carbon sink of agricultural ecosystems. In this study, a new round of soil sample collection was carried out based on historical sampling information, and a 100-d incubation experiment was carried out. Then, the data were fitted to a three-pool first-order kinetics model to estimate the MRT of active SOC pool(MRT_(a)) and slow SOC pool(MRT_(s)). We analyzed the spatiotemporal variations and the influencing factors of MRT_(a)and MRT_(s)in surface paddy soil in Dongxiang of Jiangxi Province from 2009 to 2019. The results showed that the MRT_(a)and MRT_(s) of paddy soil in Dongxiang in 2019 were 26.5 days and 14.1 years, respectively, both of which showed no significant changes compared with that in 2009. The active and slow SOC pools in the southern Dongxiang were generally more stable than the other areas. There were obvious spatiotemporal variations both in MRT_(a)and MRT_(s)in red paddy soil in Dongxiang, with the variation ranges of-1.3%-544.5% and-6.7%-1375.5%, respectively. Such variations were partly due to the spatial differences in the proportion of active and slow SOC pools in the total SOC. Compared with other rice-growing areas in southern China, the SOC pool of red paddy soil in Dongxiang was more stable in recent 10 years, despite substantial spatial variation.

关 键 词：红壤性水稻土 活性碳库 缓效性碳库 平均驻留时间 时空分异 

分 类 号：S153.6[农业科学—土壤学]