Abstract:A four-year field experiment was carried out in paddy field at white soil to study the effects of different fertilizations on carbon contents of soil humus components. The treatments consisted of two tillage depths of 10 cm and 20 cm (T10, T20) and four fertilizations of chemical fertilizer (F), chemical fertilizer and farmyard manure (F+M), chemical fertilizer and wheat straw (F+S), chemical fertilizer and green manure (F+G). The water-soluble substance, humic acid, fulvic acid and humic material of white soil were extracted using composition method. The results showed that carbon contents in bulk soil and humic substances in T20+F treatment were lower than in T10+F treatment. The addition of organic manure with the tillage depth of 20 cm significantly increased the contents of total organic carbon and humus components. Compared with T20+F treatment, total organic carbon and organic carbon contents of humic acid, fulvic acid and water-soluble substance in T20+F+M, T20+F+S and T20+F+G treatments were increased by 14.57%–30.64%, 10.36%–30.57%, 0.74%–12.31% and 14.25%-26.80%, respectively. The addition of organic manure significantly increased organic carbon contents of humic material by 18.87%-35.78% in T20+F+M, T20+F+S and T20+F+G treatments, compared with T20+F treatment. Different tillage depths and fertilizations showed no significant effect on humus properties. The addition of organic manure increased PQ values, HA/FA ratio, E4/E6 values and ΔlogK to a certain extent. Correlation analysis showed significant or extremely significant positive correlations existed among humic material, humic acid, fulvic acid and total organic carbon, while no correlation with water-soluble substance.