Abstract

Physical and geochemical properties of six soils developed on tephra from Mts. Kupe and Manengouba were studied in order to assess the degree of weathering of the tephric parent materials. Physico-chemical properties were determined following standard procedures. Total elemental contents and selective extracted contents of Al and Fe by acid ammonium oxalate, dithionite-citrate-bicarbonate (DCB) and pyrophosphate were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES) after being brought into solution. Parent rocks were chemically classified as hawaiite, tephricfoidite, and basanites, while soils were classified as Andosols and Cambisols. Both the soils and parent rocks have high concentrations in SiO₂, Al₂O₃, and Fe₂O₃. Texture and the evaluated related weathering indices correlate with horizon development and are important in capturing the differences between the two Reference Soil Groups. Mobility of major elements showed erratic trends in conformity with the stratigraphic breaks indicating variability of parent materials with depth. Enrichment and depletion of major elements to a certain degree explains the ongoing andosolization process in the Andosols. Physical and geochemical data can both be used concomitantly for assessment of weathering trends in these soils. Total reserve in bases (TRB) is very high in the Andosols indicating the presence of large quantities of weatherable minerals and thus the high potential of these soils for agricultural production.

中文翻译：

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土壤理化性质和地球化学指标：喀麦隆火山沿线的特非拉衍生土壤成岩作用评估的诊断工具

摘要

在Mts的Tephra上发育的6种土壤的物理和地球化学特性。研究了Kupe和Manengouba，以评估特发性母体材料的风化程度。按照标准程序测定理化性质。溶液溶解后，使用电感耦合等离子体发射光谱法（ICP-OES）测定酸性草酸铵，连二亚硫酸氢盐-碳酸氢盐（DCB）和焦磷酸盐对Al和Fe的总元素含量和选择性萃取含量。母体岩石在化学上被分类为夏威夷岩，斜方岩和Basanite，而土壤则被分类为Andosols和Cambisols。土壤和母体岩石中的SiO ₂，Al ₂ O ₃和Fe的浓度都很高₂ O ₃。质地和评估的相关风化指数与地层发育相关，并且对于捕获两个参考土壤组之间的差异非常重要。主要元素的流动性与地层断裂一致，显示出不稳定的趋势，表明母体材料随深度的变化。主要元素的富集和消耗在一定程度上解释了Andosols中正在进行的Andosolization过程。物理和地球化学数据都可以同时用于评估这些土壤的风化趋势。在Andosols中，碱的总储量（TRB）非常高，表明存在大量耐候矿物，因此这些土壤在农业生产中的潜力很大。