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作 者 ：田昆,陈宝昆,贝荣塔,罗开华,王有位,杨永兴

期 刊 ：生态学报 2003年 23卷 9期 页码：1937~1943

关键词：原状土；就地培养；氮库动态变化；矿质化；土壤退化；

Keywords:soil core, in situ exposure, N fluxes, mineralization, soil degradation,

摘 要 ：利用原状土连续就地取样(sequentialcoringandin-situexposure)方法研究了澜沧江流域典型退化土壤的氮库营养动态变化过程,监测了矿质氮在时间和空间上的释放与固定、淋失与植物吸收消耗。结果表明人为干扰影响土壤氮矿质化,导致氮固定、淋失,引起养分衰减退化。从阔叶林转变为果园、坡耕地、桉树林和针叶林,矿质氮60d内平均衰减分别为51.51,29.64,26.84,16.40mg·kg-1,变异程度依次为21.5%、11.0%、14.2%、8.3%,氮固定分别为15.45,8.51,13.90,0.00mg·kg-1,淋失量则坡耕地最大,达44.50mg·kg-1,其次是针叶林和桉树林地,分别为38.41和25.30mg·kg-1。植物对土壤氮的吸收消耗为果园>坡耕地作物>桉树林>针叶林>阔叶林,利用形态以硝态氮为主。

Abstract:Both soil disturbance and soil utilization type changes markedly affect rates of soil N mineralization. It is generally impossible to assess the usefulness of most estimates of N mineralization as predictors of field rates because of the unknown effects of assay conditions. A methodology for fluxes of mineral N, based on sequential soil coring and in situ exposure of largely undisturbed soil columns confined within metal tube, to research the soil mineral N‘s release and immobilization, plant up take...

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