Abstract:Based on two-year wheat/maize rotation field experiment on coastal salinized Fluvo-aquic soil,the effects of different soil amendments on soil aggregates distribution and stability,organic carbon content and the contribution rates of different size class aggregates to total organic carbon had been studied. The field experiment consisted of 3 treaments,no soil amendments (CK),organic soil amendments (OSA),and organic-inorganic compound soil amendments (CSA). Soil samples were collected for analysis of soil aggregates distribution,water-stable macro-aggregates (R0.25),mean weight diameters (MWD),geometric mean diameters (GMD),fractal dimension (D),soil organic carbon storage (SOCS) and its distribution in aggregates. The results showed that the composition of soil aggregates in the coastal salinized Fluvo-aquic soil was dominated by <0.25 mm water-stable aggregates. The application of soil amendments significantly increased the number of large aggregates (>0.25 mm),and the effects on >5 mm and 2~5 mm aggregates were the highest among different aggregates. Compared with CK,the numbers of >5 mm and 2~5 mm aggregates under OSA treatment significantly increased by 167.38% and 59.00%,while those under CSA treatment significantly increased by 89.17% and 100.66%. The MWD and GMD were significantly increased under the OSA and CSA treatments,which suggested that the application of OSA and CSA increased the number and stability of large aggregates. The SOC content of all aggregates fractions under OSA and CSA treatments were higher than those under CK after two-year located trials,and the effects on 1~2 mm and 2~5 mm aggregates were the highest under the OSA and CSA treatment,respectively. As the application of soil amendments,SOC accumulated within macroaggregates,which has a relatively faster turnover rate. Compared with CK,the application of soil amendments significantly increased the contribution rate to the total SOC in >2 mm size of aggregate by 93.62%~109.76%,while it reduced or significantly reduced in <1 mm size aggregate by 20.55%~24.92%. Therefor,the application of soil amendments is the effective method to improve the stability of soil water-stable aggregates and increase the SOC content of macro-aggregates,as well as further promote the sequestration of organic carbon in wheat/maise rotation system.