Multi-parameter assessment of soil quality under Miscanthus x giganteus crop at marginal sites in Île-de-France

Abstract

In the context of increasing biomass cultivation for energy production in Europe, the objective of this study was to carry out a multi-parameter assessment of soil quality under Miscanthus x giganteus crop at marginal sites. Chemical (pH, organic carbon, total nitrogen, C:N, metal trace elements), biological (microbial biomass, earthworm communities) and physical (aggregate stability, bulk density) soil properties were evaluated 5 years after planting Miscanthus on a polluted (CH) and unpolluted (MG) marginal sites and compared with adjacent undisturbed meadow areas and Miscanthus crop cultivated on an arable field (BF). The effect of Miscanthus on soil quality was site dependent and related to soil properties (texture), metal trace element (MTE) contamination and previous land use. At MG, where Miscanthus was cultivated on a previously undisturbed meadow, results suggested a negative effect of Miscanthus on soil biological properties with a lower earthworm abundance and biomass, and a worst functional and species structure in the Miscanthus than in the undisturbed meadow, despite a good yield. Results under Miscanthus at BF were similar in terms of soil quality to Miscanthus at MG and higher than under Miscanthus at the polluted site (CH). At CH, results suggested that Miscanthus may reduce the mobility of MTE, however further longer term studies, at a range of sites are needed to conclude about the impact of Miscanthus on soil quality at contaminated and/or uncontaminated sites.