中文摘要：

研究不同管理措施下黑土有机碳、氮组分的变化特征是深刻认识和理解黑土固碳的基础。本文以黑龙江省农业科学院31年的长期定位试验为基础,采用物理分组法对土壤不同粒径颗粒进行分离,分析6种不同施肥处理31年后,黑土表层（0~20cm）及亚表层（20~40cm）土壤有机碳、氮在粗砂粒、细砂粒、粉粒及黏粒中的分配与富集特征。结果表明：长期施用有机肥可显著提高土壤有机碳、全氮在粗砂粒和黏粒中的分配比例。在表层土壤,有机无机配施（NPKM）处理下粗砂粒有机碳和全氮的分配比例比对照分别提高191.3%和179.3%,单施有机肥（M）处理下黏粒组分的有机碳和全氮的分配比例提高分别45%和47%。亚表层土壤施用有机肥处理各粒级有机碳、氮含量的提高比例低于表层土壤。在表层和亚表层的粉粒组分中,贮存的有机碳占总储量的42%~63%和48%~54%,全氮占总储量的34%~59%和41%~47%。表层土壤施用有机肥可显著增加粗砂粒中有机碳、氮的富集系数,其中有机肥配施化肥（NPKM）处理富集系数最高（2.30和1.88）,而黏粒组分的有机碳、氮富集系数对长期施肥无响应。

英文摘要：

The characteristics and changes of soil organic carbon （ SOC ） and total nitrogen （TN） in different size particles of soil under different agricultural practices are the basis for better under- standing soil carbon sequestration of mollisols. Based on a 31-year long-term field experiment loca- ted at the Heilongjiang Academy of Agricultural Sciences （Harbin）, soil samples under six treat- ments were separated by size-fractionation method to explore changes and distribution of SOC and TN in coarse sand, fine sand, silt and clay from the top layer （0-20 cm） and subsurface layer （20-40 cm）. Results showed that long-term application of manure （M） increased the percentages of SOC and TN in coarse sand and clay size fractions. In the top layer, application of nitrogen, phosphorus and potassium fertilizers combined with manure （NPKM） increased the percentages of SOC and TN in coarse sand by 191.3% and 179.3% compared with the control （CK） , whereas M application increased the percentages of SOC and TN in clay by 45% and 47% respectively. For subsurface layers, the increase rates of SOC and TN in corresponding parts were lower than that in top layer. In the surface and subsurface layers, the percentages of SOC storage in silt size fraction accounted for 42%-63% and 48%-54%, TN storage accounted for 34%-59% and 41%-47%, respectively. The enrichment factors of SOC and TN in coarse sand and clay fractions of surface layers increased significantly under the treatments with manure. The SOC and TN enrichment factors were highest in the NPKM, being 2.30 and 1.88, respectively, while that in the clay fraction changed little in the subsurface layer.