Analysis Of Soil Organic Carbon Of Eucalyptus Plantation

Soil Organic Carbon (SOC) has been paid great attention recently as it's contributes to CO2 emission. Forest management, to some extent, could disturb the SOC pool. This research examined forest top 1 m soil after planted in 1 year (1a),3 year (3a),5 year (5a) and 7 year (7a), which generally represented the 4 stages during a rotation period (7 years). The soil was treated after extracted with KMnO4,Na2S2O8,and HF in order to determine the Easily Oxidized Carbon (EOC), Chemical Recalcitrant SOC (Na2S2O8-resist SOC) and Mineral-associated SOC (HF-soluble SOC), respectively. The SOC concentrations decreased with the soil depth increment, and the SOC density were 48.71 Mg ha-1 (±12.22),66.06 Mg ha-1 (±11.28),52.20 Mg ha-1 (±16.33) and 57.66 Mg ha-1 (±13.40) for 1a,3a,5a and 7a, respectively. However, the pool of EOC increased with the forest ages. The Na2S2O8-resist SOC decreased with forest ages and increased with soil increments. The HF-soluble SOC increased with soil increments but showed no significant difference with forest ages. The content of subsoil (40-100 cm) of Na2S2O8-resist SOC was significantly greater than the topsoil (0-40 cm), respectively. The Na2S2O8-resist SOC varied insignificantly during a rotation, it may indicated that the chemical recalcitrant SOC was less affected by the forest management than the mineral-associated SOC.