盐渍化弃耕地不同恢复年限土壤有机碳及其碳库管理指数变化

对干旱区盐渍化弃耕地不同恢复年限土壤有机碳及其碳库管理指数的变化进行分析，结果表明，弃耕地恢复初期土壤有机碳及活性有机碳（LOC）含量均低于弃耕地（CK），恢复3年（R3）、恢复5（R5）年和恢复10（R10）年的 LOC 都显著高于弃耕地，分别高出20．28％、16．00％和16．45％，土壤有机碳及活性有机碳含量均随着土层加深而降低，土壤碳库管理指数 CMI 在恢复初期低于 CK ，随着恢复年限的增加，R3，R5，R10土壤 CMI 显著高于CK 54．72％、19．79％和17．73％，R3、R5和 R10分别是 R1的3．20、2．48 和 2．43倍，表明干旱区盐渍化弃耕地经垦殖恢复后显著改善了土壤碳库质量，增加了土壤碳汇功能。相关分析表明，土壤 LOC 和 CMI 与土壤 Olsen－P 呈显著正相关关系，与 TOC 相比更能反映不同恢复年限土壤碳库的变化。

Changes of soil organic carbon and its carbon-pool management index in deserted salinized fields with various reclamation histories

Soil organic carbon plays an important role in the soil ecosystems. This paper studied changes of soil organic carbon and carbon-pool management index (CMI) deserted salinized fields with different reclamation history. Results showed that soil organic carbon and active organic carbon were decreased with depth of soil layer. Soil organic carbon was decreased in the first year after the reclamation, the soil labile organic carbon (LOC) of R3, R5 and R10 was 20.28%, 16.00% and 16.45% respectively higher than that in the control, reaching significant levels. Soil carbon-pool management index (CMI) was lower than CK during early reclamation stage. With reclamation forwarding, CMIs of R3, R5 and R10 were 54.72%, 19.79% and 17.73% higher than CK, respectively. R3, R5, and R10 were 3.20, 2.48, and 2.43 times as much as R1. All above indicated that soil quality was improved to a certain degree after a long-term restoration of the salinized field, and soil carbon sink was also enhanced. Correlation analysis showed that LOC and CMI were significant positive correlated to soil Olsen-P. LOC and CMI could reflect the changes of soil carbon pool in different years of reclamation, better than TOC.