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标题：Modeling of liming in acid agricultural soils of Libreville (Gabon)
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作者：Patrick HÖHENER ; Jean Aubin ONDO ; Pascale PRUDENT 等
期刊名称：Journal of Environment and Earth Science
印刷版ISSN：2225-0948
电子版ISSN：2225-0948
出版年度：2012
卷号：2
期号：9
页码：32-38
语种：English
出版社：The International Institute for Science, Technology and Education (IISTE)
摘要：Soil acidification is an ongoing natural process which can be enhanced by human activities or can be controlled by appropriate soil management practices. Two highly acidified urban garden soils, CHA and NTO, were subjected to single-extraction procedure by water to determine the extractable concentrations of Ca, Mg, K, Na, Al, Cu, Fe, Mn, Pb, Zn and . A modeling of effects of liming on soil solution was carried out from initial pH to pH 8.0 using the PHREEQC-2 code coupled with the PHREEQC.dat thermodynamic database. In NTO soil solution, liming increased the concentration of all cations, exception of Al when in CHA soil solution concentration of Ca, Cu, Fe and Pb increased. The chemical speciation of cations was evaluated in the soil solution. Basic cations Ca, Mg, K and Na were found as free forms (Ca 2+ , Mg 2+ , K + , Na + ) and sometimes complexed by sulfate (,). The concentration of the toxic free ion Al 3+ decreased quickly and was replaced by less toxic hydroxide complexes. For the other metals, relative to the total soluble metal concentrations the amounts of free Cu 2+ (1%-99%) and Zn 2+ (74%-97%) were not different in soil solutions when the amounts of free Pb 2+ (10%-93%) and Fe 2+ (65%-98%) in NTO soil solution were generally higher than those of CHA soil solution (8%-34% and 43%-84%, respectively). Statistical correlation analysis used to predict the change occurred in the concentration of the free ion in the soil studied showed significant influence of pH, and on Al 3+ , Fe 2+ , Pb 2+ and Zn 2+ . Key-words : tropical acid soils, urban garden, liming, modeling, PHREEQC-2