施用有机肥对黑土团聚体有机碳的影响

Effects of manure application on organic carbon in aggregates of black soil

采用湿筛法对不同处理下的黑土进行分离,得到4种不同大小(>2000、2000～250、250～53、<53μm)的团聚体,利用密度分组法分离出游离的轻组(freeLF)和团聚体内的颗粒有机质(iPOM),以评价有机肥对黑土团聚体有机碳的影响.结果表明:与对照相比,施用有机肥显著增加了土壤的团聚化作用,可在一定程度上抵消耕作对团聚体的破坏作用,减缓团聚体的周转.团聚体内细颗粒有机碳(fine iPOM-C)含量显著高于粗颗粒有机碳(coarse iPOM-C)含量,说明施用有机肥有利于团聚体内细颗粒有机碳的积累,是施用有机肥条件下黑土团聚体内碳固定的主要形式.

In this paper, black soil samples were separated into four sizes （ 〉 2 000, 2 000-250, 250-53, and 〈53 μm） of aggregates by wet sieving, and their free light fraction （free LF） and intra-aggregate particulate organic matter （iPOM） were isolated by density fractionation, aimed to evaluate the effects of manure application on the organic carbon in different sizes of aggregates in black soil. The results showed that compared with the control, applying manure improved soil aggregation significantly, and compensated the disturbance of tillage and slowed down the turnover of aggregates to some degree. After applying manure, the content of fine iPOM-C was significantly higher than that of coarse iPOM-C, suggesting that manure application was beneficial to the accumulation of fine iPOM-C, which is the main form of carbon sequestration in the aggregates of black soil.