中文摘要：

利用田间定位试验，研究了长期施用有机肥和化肥对黑土团聚化作用及碳、氮含量的影响。团聚体分级结果表明，小团聚体是土壤的主要组成部分，占土壤重量的48．86％-60．24％。长期施用有机肥可显著增加土壤中大团聚体的比例，提高土壤团聚体的稳定性；而化肥的施用则增加了土壤中微团聚体和粉＋黏粒的含量，降低土壤团聚体的稳定性。施用有机肥能显著增加土壤有机碳和总氮的含量，而化肥只有与有机肥配施时才能显著增加土壤有机碳和总氮的含量。有机肥的施用能够降低土壤C／N，表明有机肥的施用更有利于土壤氮素水平的提高。

英文摘要：

The effect of long-term organic and chemical fertilizer application on aggregation and carbon and nitrogen contents in mollisol was investigated through long-term located experiment. The results of aggregate fractionation showed that small aggregate was dominant in soil, accounting for 48.86%-60.24% of soil mass. The percentage of large macro-aggregate in soil increased significantly with manure application and the stability of aggregate was improved as well. However, the percentage of microaggregate and silt ＋ clay fraction increased and stability of aggregate decreased with chemical fertilizers addition. Manure application increased the contents of soil organic carbon and total nitrogen, while chemical fertilizers could not improve their content until being combined with manure. The ratio of C and N in soil with manure application was lower than that without manure application, suggesting that manure application favored the improvement of nitrogen in soil.