Objective]Soil aggregates are an essential material foundation of soil structure and an important carrier of soil nutrients. Rhizosphere is the most active region of matter and energy exchanging between crop and soil,and it differs from the bulk soil in many of physical and chemical conditions and biochemical processes,thereby influencing soil aggregation. A number of studies have been reported paying attention mostly to effects of organic manure application,tillage management and some other regulatory measures on soil aggregates during fallow seasons,rather than to differences of rhizospheric soil from bulk soil in dynamic variation of soil aggregate composition during the rice growing seasons. It is of great significance to study changes in volume of soil aggregates and contents of organic carbon and nitrogen therein in the rhizospheric and non-rhizospheric soils during the rice growing season to revelation of impacts of artificial cultivation on the changes and in-depth understanding of interactions between plant and soil and variation of soil quality.[Method]A field rhizo-bag experiment using two types of red paddy soils different in fertility was conducted in the Yingtan National Field Observation and Research Station of Farmland Ecosystem,Jiangxi Province,China. The soils were collected from the topsoil layers(0~15 cm)of two typical paddy fields near the station in March 2012. Two-layered root bags were used to separate rhizosphere from non-rhizosphere and bulk soil. During the experiment,root bags and the soils around were collected before rice transplanting and at the tillering,booting and maturing stages of rice,separately. The rhizosphere and non-rhizosphere soils were saved individually and separated into five aggregate-size fractions(>2 mm,1~2 mm,0.25~1 mm, 0.053~0.25 mm and <0.053 mm)using the wet sieving method. Mass fraction,percentage of aggregate destruction(PAD)and mean weight diameter(MWD)of water-stable macro-aggregates were calculated to determine stability of the aggregates. Organic carbon and total nitrogen in the aggregates were measured.[Result] Results show that the aggregates in the low fertility soil were dominated mainly with the fraction of >0.25 mm macro-aggregates(56.2%~64.0%),and the amounts of 0.25~1 mm size was the highest. Except for the aggregates 1~2 mm in size,all the fractions of aggregates in the rhizosphere soil changed significantly in content during the rice growing season. Sampling time and interactions between sampling time and rhizospheric effect remarkably affected the amounts of the fractions of 0.25~1 mm and 0.053~0.25 mm. In the high fertility soil,<0.25 mm micro-aggregates accounted for 59.8%~72.0% of the total soil aggregates,and the 0.053~0.25 mm fraction made up the largest proportion. Sampling time affected the content of >0.25 mm macro-aggregates the most,while interactions between rhizospheric effect and sampling time did the content of >2 mm fraction the most. Compared with non-rhizospheric soils,rhizospheric soils were low in PAD,but high in MWD,which indicates that rice cultivation helps improve stability of rhizosphere soil. Contents of organic carbon(SOC)and total nitrogen(TN)were the highest in the 1~2 mm fraction of aggregates and the lowest in the 0.053~0.25 mm fraction,and obviously much higher in macro-aggregates than in micro-aggregates. The SOC content in rhizosphere aggregates during the crop maturing period did not have much difference from that before rice transplanting. But SOC contents in rhizosphere aggregates did fluctuate significantly during the tillering and booting stages of rice. The SOC content in the 0.053~0.25 mm fraction was significantly influenced by sampling time. In the low fertility soil,there was no significant difference in aggregate-associated SOC contents between rhizosphere and non-rhizosphere soils. But in the high fertility soil,SOC contents in the >2 mm fraction at the tillering stage,in the 1~2 mm fraction at the booting stage and in the 0.053~0.25 mm fraction and <0.053 mm fraction at the maturing stage were significantly lower in the rhizospheric soil than in the non-rhizospheric soil. The growth of rice decreased the content of TN in macro-aggregates. The effect of rice growth was more significant in the high fertility soil. [Conclusion]In the low fertility soil,rhizospheric effect affects mainly the composition and stability of aggregates,while sampling time does contents of SOC and TN in aggregates. In the high fertility soil, composition of aggregates and distribution of SOC and TN vary under the joint impact of rhizospheric effect and sampling time.%研究水稻种植期间表层土壤团聚体数量及其有机碳、全氮含量的变化，对揭示人为耕作的影响、认知土壤肥力的演变规律具有重要意义。选择两种不同肥力的红壤性水稻土进行田间根袋试验，分别于水稻插秧前、分蘖期、孕穗期和成熟期采样，分析了水稻生长过程中根际和非根际土壤团聚体组成、稳定性以及有机碳、全氮分布的动态变化。结果表明，低肥力土壤团聚体以＞0.25 mm大团聚体为主（56.2%～64.0%），0.25～1 mm粒级团聚体含量最高；除1～2 mm粒级外，水稻生育期内根际土壤各粒级团聚体含量均有显著变化；取样时期、根际作用与取样时期的交互效应对0.25～1 mm和0.053～0.25 mm粒级含量有显著影响。高肥力土壤中以＜0.25 mm微团聚体为主（59.8%～72.0%），0.053～0.25 mm粒级团聚体比例最高，取样时期显著影响＞0.25 mm大团聚体含量，根际作用与取样时期的交互效应对＞2 mm粒级含量有极显著影响。与非根际相比，根际土壤大团聚体的破坏率较低，平均重量直径（MWD）较高，种植水稻有助于提高根际土壤的稳定性。两种肥力土壤团聚体中有机碳和全氮含量均表现为1～2 mm粒级最高，0.053～0.25 mm粒级最低，大团聚体中显著高于微团聚体。根际土壤中，水稻成熟期各粒级团聚体有机碳含量与插秧前无显著差异，而分蘖期和孕穗期有明显波动；水稻的生长降低了大团聚体中的全氮含量，对高肥力土壤的影响更为显著。总体而言，低肥力土壤中，根际作用主要影响团聚体组成和稳定性，取样时期影响团聚体碳氮含量；高肥力土壤中，团聚体组成和碳氮分布受根际作用和取样时期的共同影响。
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