用δ^(13)C法研究黑土有机碳组分的变化规律

Study on Dynamic Change of Soil Organic Carbon Composition in Phaeozem by δ()^(13)C Method

通过室内短期培养实验,利用δ13C的方法研究了小麦秸秆分解过程中黑土有机碳组分的变化规律。结果表明:有机物料本身含有相当数量的腐殖物质,这些物质的加入对土壤中有机碳的更新与活化有重要的作用。黑土中添加小麦秸秆后,土壤有机碳各组分的含量明显增加。随着培养时间的延长,土壤有机碳各组分的含量在不断变化,新形成的和原土中的HA与FA间发生转化,而且主要以FA向HA转化为主,原土的HA与FA间的转化速度比新形成的HA和FA的转化速度相对较慢。最初FA的形成速度大于HA的速度。随着培养时间的延长,由于部分FA向HA转化,加速了HA的形成,最终土壤HA与FA皆呈积累趋势,且HA的增加量显著大于FA。土壤中新形成的FA比原有的FA分解速度快。

Dynamic change in phaeozem soil organic carbon (SOM) composition in an shorter incubation experiment was studied during wheat stalk (WS) decomposition by δ()^(13)C method. The results showed that organic matter own contained many humic matter, which was beneficial of SOM renewal.SOM composition content obviously increased after it was added organic matter. With the time of incubation,the different composition content of SOM gradually changed, HA and FA transformed each other in new formed and original SOM, and the same trend that FA transformed into HA,the transformed rate in original SOM was relatively slower than that in new-formed SOM. The initial stage of incubation, the formed rate of FA was faster than that of HA. With the time of incubation, because the part of FA transformed into HA,accelerated the formation of HA ,finally HA and FA all trended to accumulation, and the increased amounts of HA was obviously more than that of FA. The decomposition rate of FA in new-formed SOM was faster than that in original SOM.