Environmental and Socio-economic Impact Assessment of the Switchgrass Production in Heavy Metals Contaminated Soils

The increased demand for biomass to produce bioenergy is arousing prices and land-use concurrence. These conflicts may be solved by producing dedicated crops for energy on surplus land that cannot be used for food, feed, nature conservation, or urbanization, reducing the indirect land-use change (ILUC) problems. This work aims to evaluate the environmental and socio-economic impact of switchgrass production in heavy metals contaminated soils. To determine ecological, social and economic sustainability, different categories were studied: energy balance, gases emission, land use, biological and landscape diversity, cost savings/losses, costs of CO2 abatement, consumers/producer's acceptance and potential employment creation. Overall results suggest that switchgrass production in heavy metals contaminated soils has positive aspects and others less positive over switchgrass production in non-contaminated soils. The productivity loss in Cu and Zn contaminated soils reduces the energy, costs, and greenhouse savings but may contribute to improve the biological and landscape diversity and the soil and waters quality. In Pb and Cd contaminated soils, there was no adverse effect on the productivity, and after that, no effects on the environmental and socio-economic aspects, compared to non-contaminated soils. Yet, in Cr contaminated soils, the toxicity affected the switchgrass significantly, and no productivity was observed.