中国科学院重庆绿色智能技术研究院机构知识库

In order to find the intrinsic correlation between water eutrophication and transformation of nitrogen in soil of water level fluctuating zone (WLFZ) of Three Gorges Reservoir Areas (TGRA), the method of sequential extraction process was applied to analyze the content and distribution characteristics of total transferable nitrogen (TF-N) in the mainstream of Yangtze River (Wanzhou section) and its tributaries of Mixi and Zhuxi River. The results showed that, compared with the main stream, the contents of soil organic matter (SOM) and total nitrogen (TN) were higher, while cation exchange capacity (CEC) and pH value were lower in the tributaries during the dry period. The main species of TF-N in soil was organic matter-sulfide form of nitrogen (OSF-N) in the WLFZ and the content of different TF-N species was in the order of OSF-N>iron-manganese oxide form of nitrogen (IMOF-N)>ion extractable form of nitrogen (IEF-N)>carbonate form of nitrogen (CF-N). The spatial distribution pattern of total TF-N was in the order of Zhuxi River>Mixi Valley>the main stem of Yangtze River. There were no significant differences between IEF-N and OSF-N contents both in the main and tributaries of Yangtze River. The distribution of CF-N and IMOF-N had similar patterns, whereas the TF-N showed a reverse pattern in comparison with the former two species in the main and tributary of Yangtze River, which was a main factor of TF-N differences between the main steam and tributaries of the Yangtze River. © 2016, Science Press. All right reserved.

为探明三峡支流水体富营养化频发与库岸消落带土壤氮素"源-库"关系转化之间的内在关系,采用分级浸提法,分析了三峡库区长江万州段干流、苎溪河支流、密溪河支流消落带落干期土壤可转化态氮含量和分布特征.结果表明,与三峡库区万州段干流相比,支流消落带落干期土壤有机质和总氮含量较高,而阳离子交换量(CEC)和p H值较低.三峡干支流消落带土壤可转化态氮(TF-N)以OSF-N(有机态和硫化物结合态)为主,且含量上OSF-N>IMOF-N(铁锰氧化物结合态氮)>IEF-N(离子交换态氮)>CF-N(碳酸盐结合态氮);而空间分布上,TF-N表现为：密溪河>苎溪河>长江干流,4种TF-N形态中IEF-N和OSF...