玛纳斯河流域盐渍化弃耕地新垦土地对土壤有机碳及团聚体稳定性的变化分析

目的]对玛纳斯河流域不同恢复模式下盐渍化弃耕地土壤有机碳及团聚体稳定性的变化特征进行分析.方法]以玛纳斯河流域为背景,选取典型的重度盐渍化弃耕地为试验区.随着弃耕地变成棉田年限的增加,土壤有机碳（SOC）含量增加,开垦2、5和10年的土壤微生物生物量碳（MBC）和易氧化有机碳（LOC）的含量以及土壤水溶性有机碳（WSOC）和土壤热水溶性有机碳（HWSOC）的含量较弃耕地高.连续人工开垦后SOC和大团聚体（＞1 mm）含量增加,土壤团聚体稳定性增强,其中开垦10年0～5、5～10 cm土层＞1mm团聚体分别占56.9％和56.7％,团粒指数下降至43.9％.结论]水稳性团聚体的含量与SOC和土壤HWSOC达到0.05水平显著正相关.玛纳斯河流域盐渍化弃耕地新垦土地对绿洲农田土壤HWSOC对维持土壤团聚体稳定性的贡献明显.

Change Analysis of Soil Organic Carbon and Aggregate Stability of Newly Reclaimed Field of Salinization Abandoned Farmland in the Manas River Valley

Objective]To analyze variation characters of soil organic carbon and aggregate stabilityof salinization abandoned farmland in Manas River Valley under different restoration modes.Method]Manas River basin was used as the background,selecting a typical severe salinization abandoned land as test area.With the increase of abandoned farmland becomes cotton field,the soil organic carbon （SOC） content increased soil MBC and LOC content,and soil water-soluble organic carbon （WSOC） and hot water-soluble organic carbon in soil （HWSOC） content improved significantly.Reclamation 2 year,5 years and 10 years,respectively,higher than the abandoned farmland soil HWSOC.After continuous artificial cultivation SOC and large aggregates （＞ 1 mm） were increased,and soil aggregate stability was enhanced,which reclaimed 10 years 0-5cm,5-10 cm soil ＞ 1 mm aggregates accounted for 56.9％ and 56.7％,aggregate index fell to 43.9％.Conclusion]Organic carbon content and soil water-stable aggregates （SOC） and soil HWSOC achieve significant positive correlation,the Manas River Salinization Wasteland newly cultivated land to oasis farmland soil HWSOC contribution to maintaining the stability of soil aggregates significantly.