Impact of pig slurry and green waste compost application on heavy metal exchangeable fractions in tropical soils

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• 作者：Emmanuel Doelsch ; Arm ; Masion ; Gé ; raud Moussard ; Claire Chevassus-Rosset ; Olivia Wojciechowicz
• 关键词：Trace element ; Agricultural waste recycling ; Volcanic soil ; Ré ; union
• 刊名：Geoderma
• 出版年：2010
• 出版时间：15 March 2010
• 年：2010
• 卷：155
• 期：3-4
• 页码：390-400
• 全文大小：1281 K

文摘

Six soil/waste samples were incubated at 28 °C under standard conditions to assess the impact of organic waste applications on heavy metal (HM) exchangeable fractions. The three studied soils are representative of the pedological diversity that prevails in Réunion and characterized by high natural total Cr, Cu, Ni and Zn concentrations. For organic waste, we tested two products that differed in their chemical composition, physical state and different HM contents, i.e. pig slurry (PS) and green waste compost (CT), which were incorporated at dosages consistent with the actual agricultural setting: 350 and 1000 kgN hap>− 1p> (subsequently called 350 and 1000). Variations in pH and electrical conductivity (EC) were monitored during incubation, while also measuring carbon mineralization and HM exchangeable fractions (Cr, Cu, Ni and Zn). The physicochemical parameter variation patterns were not identical in the three soils. The greatest variations were noted in the cambisol: pH reduction and EC increase. Conversely, in the andosol, there were only slight variations in pH and EC during incubation. The C–CO₂ quantities detected were derived from PS mineralization, and were always higher than those from the mineralization of CT, irrespective of the soil considered, and C mineralization was proportional to the initial quantity of incorporated waste (350 vs 1000). We explained the difference in the andosol mineralization coefficient between the 350 and 1000 dosages as being the result of an interaction between the organic constituents and the pseudo-cristallized aluminosilicates from the soil (allophane and/or imogolite), which limited degradation of the incorporated organic matter (OM). Despite organic waste mineralization, the pH variations recorded during the incubations and the increased salinity, we did not detect any increase in the HM exchangeable fractions, but instead noted a decrease in the Cu exchangeable fraction (soil + PS incubation), which could be explained by complexation of this element by the OM.