Abstract:Soil samples were collected from a field that had been under long-term fertilization experiment for 22 years, in the Red Soil Institute of Jiangxi Province in Jinxian County for analysis of effects of fertilization on distribution of aggregates, and organic carbon and nitrogen sequestration in aggregates of different sizes. The experiment had 9 treatments, i.e. ① CK, ② N, ③ P, ④ K, ⑤ NP, ⑥ NK, ⑦ NPK, ⑧ 2NPK and ⑨ NPK+OM. Results showed that organic carbon and nitrogen were mainly sequestrated in macroaggregate, 2~0.25 mm in size, and C/N ratio of aggregates decreased with aggregate size. The formation of aggregates in the red paddy soil was closely related with organic carbon content, displaying a phenomenon in conformity with the classical "stratification" mechanism of the aggregate-SOM interactions. The treatments of P, K, NK and NPK+OM prominently increased the content of macroaggregates and stability of aggregates. And the combined treatment of NPK+OM also increased organic carbon and nitrogen concentration in bulk soil and sequestration in aggregates of different sizes.