Abstract:Taking the reclaimed soil backfilled with coal ash in the Ji’ning region as the research objects, the spatial distribution characteristics of organic carbon components (WDOC, POC, MOC, LFOC, HFOC, MBC) in the reclaimed soil under three different utilization modes: garden land, cultivated land and forest land. The results showed that: (1) The total carbon (TC), soil organic carbon (SOC) and soil organic carbon density (SOCD) of the three different utilization modes were lower than the control. The sizes of TC, SOC and SOCD in different utilization modes: garden land>forest land>cultivated land. (2) The difference of organic carbon components between different utilization modes was significant (P<0.05), there were significant positive correlations between the organic carbon and other components. By correlation analysis, specific gravity analysis and sensitivity analysis, the lower contents of MOC and HFOC resulted in the lower soil organic carbon in reclaimed soil than the control. (3) According to the organic carbon component enrichment index, the composition of the garden was recovered well in the 0—40 cm soil layer, the forest land recovered well in 40—60 cm, bute not so much for the recovery in cultivated land. For the composite index of 0—60 cm soil layer, it turned out that garden land>forest land>cultivated land. In a word, through analyzing the organic carbon composition, the best utilization mode is garden land, which is worth further promotion.