Organo-mineral clay and physical properties in COST 622 European volcanic soils
Organo-mineral clay and physical properties in COST 622 European volcanic soils
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COST 622 欧洲火山土壤中的有机矿物粘土和物理特性
DOI：
10.1007/978-3-540-48711-1_34
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
G. Burtin
中科院分区：
文献类型：
--
作者：
F. Bartoli;G. Burtin
粒度分布无疑是土壤的一个基本特征，不仅在农学上有用，而且在土壤分类中也很有用。尽管如此，现在有充分的文献证明（如Nanzyo等人1993年的评论，Mizota和van Reeuwijk 1993年的评论），安度溶胶（WRB 2001）在与其他土壤成功使用的分散剂（如六正磷酸钠，这是根据ISO国际土壤粒径分析标准推荐的分散剂）接触时不能完全分散。六偏磷酸钠之所以不能完全有效地获得分散液，应归因于这种分散剂对allophane的亲和力很强，导致了边到边的絮凝聚集体。此外，当湿火山灰土壤干燥时，粘土的分散性降低。这是由于在干燥过程中发生的不可逆的结构和机械变化（如Kubota 1972， Nanzyo等人1993）。因此，与现场测定相比，常见的实验室测定的allophanic andools粒度分析显示粘土含量低至非常低（Ping et al. 1989），并且基于1500千帕保水率，使用粒径/矿物学修饰剂，如灰质，中质和含水，来取代土壤分类（ST 1999）中andools粒度类别的名称。因此，本研究的首要目标是适应和发展na树脂方法，而不破坏有机物或/和无序矿物，以获得大多数有机矿物粘土组分。这种Na-resin方法已经被推荐用于强团聚土壤，如Oxisols和Andisols （Bartoli et al. 1991, Churchman et al. 1999）。本研究的第二个目的是将有机矿物粘土的数量与土壤的物理性质联系起来，如体积密度、毛细孔隙度（由毛细上升获得）和未受干扰的湿土芯在受控40℃干燥动力学结束时的总体体积收缩。事实上，
The particle-size distribution is undoubtedly a basic soil characteristic as useful in soil classification as it is in agronomy. Nevertheless, it is now well documented (see, eg the reviews of Nanzyo et al. 1993, Mizota and van Reeuwijk 1993) that Andosols (WRB 2001) fail to disperse completely when submitted to the dispersion agents that are utilized with success with other soils (eg sodium hexametaphosphate which is the recommended dispersant agent following the ISO international standards of soil particle-size analysis). The fact that sodium hexametaphosphate is not completely effective in obtaining dispersion should be attributed to the strong affinity of this dispersing agent for allophane, leading to edge to edge flocculated aggregates. Also, clay dispersability decreases when wet volcanic ash soils are dried. This is due to irreversible structural and mechanical changes occurring during drying (eg Kubota 1972, Nanzyo et al. 1993). Therefore, the common laboratory determined particle-size analysis of allophanic Andosols shows a low to very low clay content as compared with field determination (Ping et al. 1989), and particle-size/mineralogy modifiers such as ashy, medial and hydrous, based on 1500 kPa water retention, are used to replace the names of particle-size classes for Andisols in Soil Taxonomy (ST 1999).The first aim of this study is therefore to adapt and develop the Na-resin method, without destruction of organic matter or/and poorly-ordered minerals, for obtaining most of the organo-mineral clay fraction. This Na-resin method was already recommended for strongly aggregated soils such as Oxisols and Andisols (Bartoli et al. 1991, Churchman et al. 1999). The second aim of this study is to relate amounts of organo-mineral clay to physical soil properties such as bulk density, capillary porosity obtained by capillary rise, and total volumetric shrinkage of wet undisturbed soil cores at the end of controlled 40 C drying kinetics. As a matter of fact,