中文摘要：

【目的】土壤团聚体不仅是土壤结构的重要单元,也是土壤有机碳和氮素固持的重要场所。探究还田秸秆和有机肥中的有机碳和氮素在土壤团聚体中的残留特征,为深刻认识团聚体对外源有机碳和氮素的固持机制及土壤的可持续管理提供依据。【方法】以中国南方典型红壤（C3植物为主的自然植被）为研究对象,设置以下5个处理：（1）对照;（2）低量玉米秸秆添加;（3）高量玉米秸秆添加;（4）低量15N标记有机肥（与处理（2）等碳量）;（5）高量15N标记有机肥（与处理（3）等碳量）。采用室内模拟培养试验（恒温恒湿条件下培养300 d）,运用13C和15N同位素示踪技术,研究培养后土壤大团聚体（250—2 000μm）、微团聚体（53—250μm）、粉黏粒组分（〈53μm）中有机碳和氮含量及其同位素丰度（13C和15N）,分析外源碳氮在土壤各团聚体组分的分配比例及残留特征。【结果】培养300 d后,与对照相比,添加秸秆或有机肥显著提高土壤总有机碳和全氮含量（P〈0.05）,提高幅度随物料添加量增加而增加。低量或高量有机肥添加后土壤及各级团聚体有机碳和氮素含量显著高于等碳量的秸秆处理。与对照相比,秸秆处理显著提高大团聚体（250—2000μm）有机碳和氮的分配比例,其中,高量处理分别提高19.5和22.4个百分点;但该处理显著降低粉黏粒组分（〈53μm）有机碳和氮素分配比例,平均降低11.4和12.6个百分点。与对照相比,有机肥处理显著提高微团聚体（53—250μm）有机碳和氮素的分配比例,其中,低量有机肥处理分别提高11.6和8.3个百分点;而显著降粉黏粒组分（〈53μm）的有机碳和氮的分配比例,平均降低6.0和9.4个百分点。同位素结果显示,高量或低量秸秆处理各粒级团聚体之间,大团聚体（250—2 000μm）有机碳的δ13C值最高,其次为粉黏粒组分（〈53μm）,微团聚体（53—25

英文摘要：

【Objective】 Soil aggregates was not only one of the key structural unit, but also the most important space for soil carbon and nitrogen sequestration. The objective of this study was to explore the retention characteristics of carbon and nitrogen from corn straw and manure amendment in different size soil aggregates, which would be better understanding of the stabilization mechanism of added organic carbon and nitrogen in the aggregate and sustainable soil management.【Method】The treatments was set as follow：（1） Control;（2） straw addition in low rate;（3） straw addition in high rate;（4） manure addition in low rate（with same amount carbon in treatment（2）;（5） manure addition in high rate（with same amount carbon in treatment（3）. With isotope tracer technique of the natural abundance of 13 C and labeled 15 N, typical red soil from southern China（dominated by C3 natural vegetation） was incubated for 300 days indoor on the condition of constant temperature and humidity. The content of organic carbon and nitrogen, isotopic abundance of 15 N and 13 C in bulk soil and different aggregate size fractions were determined to analyze the distribution of added organic carbon in corn straw and nitrogen in manure, as well as the retention rate of carbon and nitrogen, in macro-aggregate（250-2 000 μm）, micro-aggregates（53-250 μm） and silt-clay size fractions（53 μm）. 【Result】 Results showed that, compared with the control, contents of organic carbon and nitrogen were significantly（P0.05） increased after additions of corn straw and manure in red soil after 300-days incubation. It also showed the more amounts of added organic amendments, the higher increments in soil organic carbon and nitrogen content. Compared with the straw addition with same amount of carbon, application of organic manure can significantly increase the content of carbon and nitrogen in different size aggregates. Compared with the Control, the distribution proportion of organic carbon and nitrogen w