“In Situ” Amendments and Revegetation Reduce Trace Element Leaching in a Contaminated Soil Alfredo Pérez-de-Mora & Pilar Burgos & Francisco Cabrera & Engracia Madejón Received: 7 March 2007 / Accepted: 17 May 2007 / Published online: 14 July 2007 # Springer Science + Business Media B.V. 2007 Abstract Various amendments and/or a plant cover (Agrostis stolonifera L.) were assessed for their potential to reduce trace element leaching in a contaminated soil under semi-arid conditions. The experiment was carried out in field containers and lasted 30 months. Five treatments with amendments (leonardite (LEO), litter (LIT), municipal waste compost (MWC), biosolid compost (BC) and sugar beet lime (SL)) and a plant cover and two controls (control without amendment but with plant (CTRP) and control without amendment and without plant (CTR)) were established. Drainage volumes were measured after each precipitation event and aliquots were analysed for pH, electrical conductivity (EC) and trace element concentrations (As, Cd, Cu, Pb and Zn). Soil pH and trace element extractability (0.01 M CaCl 2 ) at three different depths (0–10, 10–20 and 20– 30 cm) were measured at the end of the experiment. Incorporation of amendments reduced leaching of Cd, Cu and Zn between 40–70% in comparison to untreated soil. The most effective amendments were SL, BC and MWC. At the end of the experiment, extractable concentrations of Cd, Cu and Zn were generally lower in all amended soils and CTRP compared to CTR. Soil pH decreased and extractability of metals increased in all treatments in relation to depth. Results showed that use of these amendments combined with healthy and sustainable plant cover might be a reliable option for “in situ” stabilization of trace elements in moderately contaminated soils. Keywords Agrostis . Amendments . Leachates . Reclamation . Trace elements 1 Introduction Soil contamination and erosion are some of the main threats to be tackled by the EU Thematic Strategy on Soil Protection (COM 2002, 179). In semiarid regions found around the Mediterranean, reclamation of contaminated soils such as those affected by mining activities or mine spills is constrained by the climate (dry hot summers with significant fire risk and very low precipitation arriving as irregular torrential rainfall events) and soils with low nutrient and organic matter content (de Paz et al. 2006). Leaching of contaminants can negatively affect groundwater sources, which are crucial for the sustainability of both natural and agricultural systems in the Mediterranean area. Due to low vegetation cover, run-off losses in such soils may transport trace elements and other contaminants to streams and rivers. This creates conditions that favour higher erosion and disturb normal ecosystem functioning. Water Air Soil Pollut (2007) 185:209–222 DOI 10.1007/s11270-007-9443-8 A. Pérez-de-Mora : P. Burgos : F. Cabrera : E. Madejón (*) Instituto de Recursos Naturales y Agrobiología de Sevilla, Av. Reina Mercedes 10, P.O. Box 1052, 41080 Sevilla, Spain e-mail: emadejon@irnase.csic.es