秸秆还田土壤溶解性有机碳的官能团特征及其与CO_2排放的关系  

Relationship between functional groups of soil dissolved organic carbon and CO_2 emissions with crop residues incorporation to soil

作　　者：李彬彬[1] 武兰芳[1] 许艳艳 秦越[1] LI Bin-bin;WU Lan-fang;XU Yan-yan;QIN Yue(Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China)

机构地区：[1]中国科学院地理科学与资源研究所生态网络观测与模拟重点实验室,北京100101

出　　处：《农业环境科学学报》2017年第12期2535-2543,共9页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(31271675);国家科技支撑计划课题(2013BAD05B03)~~

摘　　要：土壤溶解性有机碳(DOC)是土壤有机碳的重要组成部分,其含量变化和分子结构组成均会对土壤CO_2气体排放产生影响。为了探讨秸秆还田后土壤DOC的结构特征及其与土壤CO_2排放的关系,在连续4个小麦生长季,对秸秆还田和不还田土壤DOC含量及其官能团特征和土壤CO_2排放通量进行测定分析,结果表明:秸秆还田和不还田土壤的DOC结构中均含有-C=C-、-CO-NH-和苯环这3种官能团;秸秆还田土壤DOC含量显著高于无秸秆还田土壤,而且DOC组分中的胺类物质(-CO-NH-)和芳香族化合物(-C=C-、苯环)的含量比例也明显增加;土壤CO_2排放通量也表现为秸秆还田土壤显著高于无秸秆还田土壤。土壤DOC含量、DOC官能团结构特征和CO_2排放在4个小麦生长季内的变化规律基本一致。相关分析显示土壤CO_2排放不但与DOC含量具有显著的正相关关系(r=0.86*),而且与DOC的分子结构特征显著相关(r210=0.62*;r280=0.73*),胺类物质和芳香族化合物的含量越高,CO_2排放通量越大。Dissolved organic carbon is an important component of soil organic carbon. Changes in its content and chemical composition will have a significant effect on the emission of greenhouse gases. The purpose of this study was to explore the change of soil DOC functional group, as well as its effects on CO2 emission. We carried out a plot experiment in the field to investigate the soil DOC concent, DOC func- tional groups and CO2 emissions under with and without crop residue treatments. The results showed that crop residues incorporation into soil significantly increased soil DOC content. DOC was composed of amide and aromatic compounds, which consisted of a carbon-carbon double bond, an amido bond, and a benzene ring. Returning crop residue to the soil increased the ratio of the contents of the amido bond and ben- zene ring. In addition, crop residues incorporation significantly increased the soil CO2 emission. The changes of the DOC content, DOC func- tional groups, and CO2 emission were similar during the four consecutive wheat growing seasons. Based on the correlation analysis, we found both the soil DOC content and its functional group strongly correlated to the CO2 emissions.The high CO2 emissions were observed in the soil with high contents of amide and aromatic compounds.

关 键 词：秸秆还田 溶解性有机碳(DOC) 官能团特征 二氧化碳 

分 类 号：X511[环境科学与工程—环境工程]