土地利用方式对土壤有机碳和碳库管理指数的影响

土壤碳库管理指数反映土壤管理的科学性.对比研究了干热河谷新银合欢林、苏门答腊金合欢林、大叶相思林、印楝林、荒地和旱耕地土壤有机碳(SOC)、易氧化有机碳(ROC)含量和土壤碳库管理指数.结果表明:6种土地利用方式下SOC和ROC含量范围分别为4.22～5.92 g·kg-1和1.34～2.33 g·kg-1.各利用方式...

Effects of Land Uses on Soil Organic Carbon and Carbon Pool Management Index

Carbon management index (I_CM) is used to evaluate the scientificity of soil management. Soil organic carbon (SOC) and readily oxidized carbon (ROC) contents under Leucaena leucocephala stand, Acacia glauca stand, Acacia auriculiformis stand, Azadirachta indica stand, wasteland and dry cropland were determined and their I_CM were calculated. The results showed that the SOC and ROC contents under the 6 land use types were 4.22-5.92 g·kg^-1 and 1.34-2.33 g·kg^-1, respectively. No significant differences in SOC contents among these land uses were observed. The ROC contents under the 4 types of woodland, however, were significantly higher than these under dry cropland or wasteland (P<0.05). The ROC were high significantly (P<0.001) correlated (R² is 66.3%) with SOC. Compared with wasteland, the I_CM ranged from 1.77 to 2.36 under these woodlands, and 0.99 under dry cropland. It is revealed that the litter quantity and land management under these land uses may be the key factors resulting in the variation of ROC. At ecological fragile region of Dry-hot Valley, closure management is useful to sequestrate C in woodland soils. However, the management systems for soil carbon pool under dry cropland are not in a sound way.