[Distribution of water-stable aggregates and aggregate-associated C in black soil in Northeast China].
The study on the distribution characters of water-stable aggregates and aggregate-associated C in 32 pairs of virgin and cultivated black soils in Northeast China showed that in virgin soils, the amount of water-stable macroaggregates (>0.25 mm) and their associated C in 0-30 cm layer were higher than those of microaggreagtes (< 0.25 mm). With the increase of soil depth, the amount of macroaggregates and their associated C showed a decreasing trend, while those of microaggregates increased significantly (P < 0.01). The distribution characters of aggregates in cultivated soils were in adverse to virgin soils. Compared with those in virgin soils, the amount of macroaggregates and their associated C in 0-30 cm layer in cultivated soils declined drastically, particularly for >1 mm aggregates. In virgin soils, the proportions of soil macroaggregates, especially for >1 mm aggregates, were positively correlated to soil organic carbon; but in cultivated soils, no obvious relationship was observed between them. The associated C of soil aggregates was positively correlated to soil total organic carbon in both virgin and cultivated soils (P <0.01). In cultivated soils, less C was associated with macroaggregates but 37% more C was associated with microaggreagtes, and the total soil organic carbon was decreased by 29.5%, in comparison with those in virgin soils, which suggested that soil macroaggregates played an important role in the dynamics changes of soil total organic carbon. It was indicated that soil water-stable macroaggregates were sensitive to soil management, and could be an indicator in evaluating the impacts of agronomic managements on soil fertility and soil quality.
Liang
Ai-Zhen
AZ
Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130012, China. aizhenliang@hotmail.com
Zhang
Xiao-Ping
XP
Shen
Yan
Y
Li
Wen-Feng
WF
Yang
Xue-Ming
XM
D002244:Carbon / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring; D009930:Organic Chemicals / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D014867:Water / Q000032:analysis*
D009930:Organic Chemicals; D012987:Soil; D014867:Water; D002244:Carbon