Effects of Land Use Change on Organic Carbon in Soil Aggregates

[Objective]The study aimed to determine the effects of land use change on organic carbon in soil aggregates. [Method]Using aggregate fractionation method,the change of organic carbon in soil aggregates from wetland soil to farmland soil was studied. [Result]The mass ratio of 2 000-250 μm size in soil aggregates was highest in two soils,and its value was 76.52%. The distribution pattern of organic carbon content in soil aggregates was 2 000-250 μm 50-250 μm less than 50 μm. Land use change had a remarkable effect on organic carbon in soil aggregates and the influence in the aggregate of 2 000-250 μm was the most significant. The correlation between organic carbon in 2 000-250 μm or less than 50 μm size aggregate and soil organic carbon content reached a significant level,but not remarkable in 50~250 μm aggregate. [Conclusion]The shift from wetland to farmland significantly changed the soil carbon pools,and organic carbon of the 2 000-250 μm size in aggregates was more sensitive to land-use change.