This paper comparatively studied the structural differences of particulate organic carbon(POC)in different organic fertilizations,to clear the mechanism of action of POC in soil carbon sequestration.Compared with chemical fertilization as the control,four kinds of organic material for this positioning fertilizer experiment were chosen,and the effects we analyzed of different organic fertilization on the structure of POC through the 13C Nuclear Magnetic Resonance(NMR)and Infrared Spectroscopy(IR).The results showed that POC was mainly composed of oxygen-containing groups and aliphatic structures,in which aliphaticity is higher than 75% and the content of oxygen-containing groups are higher than 50%;Different organic fertilization had greater difference impact on POC's structure,and leaves fertilization could be improve POC aromaticity.At the same time,hydrophilic also increased significantly,about 0.78% than the control;Cow dung,maize straw or leaves could increase the aromaticity of POC in the short-term,the cow dung or straw treatment was more favorable for the stability of POC.Especially the straw treatment which aromaticity was higher 0.35% and 0.11% than control and cow dung,and the hydrophilicity was far lower than the two.The results of Infrared spectrum and nuclear magnetic analysis were basically identical,infrared spectrum can be used for preliminary screening for a large number of POC samples.%为明确颗粒有机碳在土壤固碳中的作用机制,对比研究了不同有机培肥土壤颗粒有机碳的结构差异.以单施化肥处理为对照,选择了四种有机物料进行定位培肥试验,利用13C NM R和红外光谱技术对比分析不同有机培肥对土壤颗粒有机碳结构的影响.结果表明:颗粒有机碳以脂肪碳和含氧基团为主,脂化度高于75%,含氧官能团含量高于50%;不同有机培肥对土壤颗粒有机碳结构的影响差异性显著,树叶培肥在提高颗粒有机碳芳香度的同时,亲水性也大幅度提高,比单施化肥处理(对照)提高了0.78%;短期内,牛粪、秸秆和树叶培肥均可提高土壤颗粒有机碳的芳香度,但从长远角度分析,牛粪和秸秆培肥更利于土壤颗粒有机碳的稳定,尤其是秸秆培肥,其颗粒有机碳的芳香度分别比对照和牛粪培肥高0.35% 和0.11%,而亲水性远低于二者;红外光谱与核磁分析的结果基本一致,红外光谱可用于大量样品的颗粒有机碳结构初步筛选.
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