Soil Aggregate Structure Effects on Dielectric Permittivity of an Andisol Measured by Time Domain Reflectometry
Soil Aggregate Structure Effects on Dielectric Permittivity of an Andisol Measured by Time Domain Reflectometry
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DOI：
10.2136/vzj2003.9000
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发表时间：
2003-02-01
影响因子：
2.8
通讯作者：
Chikushi, Jiro
中科院分区：
文献类型：
--
作者：
Miyamoto, Teruhito;Annaka, Takeyuki;Chikushi, Jiro
各种类型的土壤物理性质受质地和结构的影响。我们的目的是确定团聚体结构对土壤介电性质的影响，用时域反射仪(TDR)测量。考察和比较了湿筛骨料及其破碎样品的体积含水率(Theta)和介电常数(Epsilon)之间的关系。在0.1毫米到2.0毫米直径的θ-epsilon关系中。湿筛的集合体，在体积含水率(临界含水率)时，theta-epsilon曲线的梯度适度变化，尽管当我们粉碎集合体结构时，这一性质消失。该临界值与高原含水率呈双峰型曲线对应。我们认为，团聚体结构对土壤介电性质的影响涉及团聚体的大小、团聚体中水分的结构、团聚体内和团聚体间孔隙中的水分充填过程以及土壤表面吸附的结合水的低e值。
Various types of soil physical properties are affected by texture and structure. Our objective was to determine aggregate structure effect on the soil dielectric property of an Andisol measured by time domain reflectometry (TDR). The relationships between volumetric water content (theta) and dielectric permittivity (epsilon) for both a wet-sieved aggregate and its crushed sample were examined and compared. In the theta-epsilon relationship for 0.1- to 2.0-mm-diam. wet-sieved aggregates, the gradient of the theta-epsilon curve moderately changed at a volumetric water content (critical water content), although this property disappeared when we crushed the aggregate structure. Furthermore, the critical value corresponded to the water content of the plateau in a bimodal-type water retention curve. We suggest that effects of aggregate structure on a soil's dielectric property are involved in the aggregate sizes, the configuration of water in aggregates, the processes of water filling in intra- and interaggregate pores, and the low e value of bound water adsorbed on soil surfaces.