Impact of miscanthus cultivation on trace metal availability in contaminated agricultural soils: complementary insights from kinetic extraction and physical fractionation.

Chemosphere

PubMedID: 23260247

Iqbal M, Bermond A, Lamy I. Impact of miscanthus cultivation on trace metal availability in contaminated agricultural soils: complementary insights from kinetic extraction and physical fractionation. Chemosphere. 2013;91(3):287-94.
In order to assess the impact of in situ energy crop cultivation on Cu, Pb, Zn and Cd availabilities in an area contaminated by atmospheric fallout, a parcel divided in two parts was sampled: one under perennial miscanthus since three years and the other staying under annual crops used as reference. Metal availability parameters determined using EDTA extractions at equilibrium and kinetic extractions were related to metal localization in size fractions after physical fractionation. Extraction at equilibrium as well as kinetically defined labile pools highlighted significantly lower Cu and Pb availabilities in the soil under miscanthus compared to the annual crop reference while physical fractionations highlighted an increased localization of these metals in the fine size fractions. For Zn and Cd, changes in metal availability were highlighted only through the kinetic parameters of extraction rate constants while localization in size fractions changed for Cd only. Indeed for these metals extraction at equilibrium and kinetically defined labile and slowly labile pools failed to show some changes. Organic carbon percentage was significantly higher in the 20-50µm and 200-2000µm fractions for the miscanthus sample underlying the importance of no-tillage and organic carbon inputs. Pearson correlations among metal availability parameters and metal and organic carbon localizations were used to identify the more important fractions involved in the metal availability. Results revealed that available metal pools were related to metal localization in the finer soil fractions (<50µm) and to the organic carbon localization in the 20-50µm and 200-2000µm fractions.