干旱区荒漠新垦土地土壤有机碳含量特征

以克拉玛依生态农业开发区为例,研究了干旱区荒漠新垦土地不同土地利用方式下的土壤有机碳与活性有机碳含量差异及其剖面分布特征,并讨论了干旱区荒漠开垦利用对荒漠"碳汇"功能的促进作用,以及土地利用方式对土壤有机碳与活性有机碳剖面分布特征的影响。结果表明:克拉玛依生态农业开发区土壤有机碳含量普遍较低。在0~20cm深度内,速生杨林地与苜蓿地土壤有机碳含量随土层加深而降低,棉花地、打瓜-棉花地耕作类土壤有机碳垂直分布相对较均匀,但是表层0~5cm土壤有机碳略低于下层,土壤活性有机碳剖面分布特征与有机碳类似。农田与林地的土壤有机碳与活性有机碳含量均明显高于荒漠,农田对土壤有机碳的汇聚作用优于人工林地。

Contents of Soil Organic Carbon in Newly Reclaimed Field in Arid Desert Zone

The changesand profile distribution of soil organic carbon and soil labile organic carbon under different uses ofnewly reclaimed field werestudied in the Karamay Agricultural Developing Area.The results showed thatsoil organic carbon in the area waslow.However,soil organic carbon in newly reclaimed field wasrelatively higher than that of desert.In 0～20 cm depth,contents of soil organic carbon of in poplar field and alfalfa fielddecreased withsoil layerdecrease,while soil organic carbon profile distribution wasevenly in arable soils such as cotton field and melon-cotton field.However,content of soil organic carbon in 0～5 cm depth waslower than the next soil layer.The profile distribution of soil labile organic carbon conformed to that of soil organic carbon.The content of soil organic carbon and soil labile organic carbon in farmland werehigher than that in poplar fields.Thus,it was be concluded that soil carbon sequestration of farmlands was better thanthat of fast-growth poplar field.