用δ~(13)C法研究黑土添加有机物料后有机碳的变化规律

通过室内短期培养实验,利用δ13C的方法研究了外源有机物料分解过程中黑土有机碳的变化规律。结果表明:黑土中添加有机物料后,土壤有机碳的数量明显增加。在有机物料分解过程中,随着培养时间的延长,土壤有机碳的总量在逐渐下降,总的变化趋势是先快后慢,渐趋平缓,到培养结束(30天),有机物料在土壤中净残留率小于50%。黑土有机碳的δ13C值受进入土壤中有机物料的种类所影响,从数量上土壤有机碳的δ13C值可以反映土壤中不同来源有机碳的变化。在小麦秸秆分解过程中,新进入黑土中的有机碳转化较快,而土壤中固有的有机碳转化较慢,添加有机物料可以增加土壤中有机碳的固定。

Dynamic Change of Soil Organic Carbon in Black Soils by δ13C Method

Dynamic change of soil organic carbon (SOC) in black soils incubation experiment over an shorter time was studied during the process of wheat stalk (WS) decomposition by δ~(13)C method. The results showed that quantity of SOC obviously increased after organic matter had been added During the process of incubation, the total content of SOC gradually decreased. The total tendency was that SOC decreased quickly in the initial stage of incubation, then slowly, and tended to smooth out in the end. When the incubation (30 days) was over, net residual rate of SW was fewer than 50%. δ~(13)C values of black soil SOC was affected by the sorts of organic carbon which could indicate the dynamic change of SOC from different source in amounts. The transformation rate of new added SOC were relatively faster than that of original SOC.The added organic matter into black soil might increase the fixation quantity of SOM.