中文摘要：

土壤团聚体组成和土壤养分状况是评价土壤肥力的两个重要指标。不同粒级的团聚体在营养元素的保持、供应及转化能力等方面发挥着不同的作用。本文通过比较长期施肥对土壤团聚体的分布和对土壤养分在团聚体分布变化的影响，全面评价长期施肥对改善土壤肥力状况的作用。结果表明：长期施肥减少〉5mm的非团粒结构的数量，增加0．25～5mm团聚体的含量，改善了土壤的物理结构；土壤大团聚体中含有更多的全C、全N、全P，因此大团聚体对养分的保持有重要作用；施肥对速效养分含量影响显著，碱解N含量随粒级的减小而增加，有利于作物的吸收；肥料的施加使得小粒级团聚体埘土壤养分储量的贡献率越来越突出，更利于养分的供给。此外，研究还发现耕作条件下有机无机肥配施不利于较小粒级团聚体全N和全P的保持。

英文摘要：

Soil aggregates and soil nutrients are two important indicators in soil fertility evaluation. Different sizes of aggregates play various roles in the maintenance, availability and transformation of nutrients. This paper compared the effects of long-term fertilization on the distribution of soil aggregates and soil nutrients in aggregates in order to evaluate the role of long-term fertilization on improving soil fertility. The results showed that long-term fertilization decreased the amount of 〉5 mm aggregates but increased the percentage of 0.25 - 5 mm aggregates, thus improved soil structure. Macroaggregate could maintain soil nutrients because it held large amount of soil total C, total N and total E The effect of fertilization on soil available nutrient was remarkable, soil available N increased with the decrease of aggregate size, which was in favor of plant absorption. In addition, the contribution rate of microaggregates to soil nutrients was intensified with fertilizer application, which was also beneficial for nutrients＇ uptake. However, microaggregates were unfavorable to preserve total N and total P with the combination of inorganic fertilizer and organic fertilizer.