ENVIRONMENTAL IMPACT ASSESSMENT OF FIBER SORGHUM (SUDAN-GRASS) PRODUCTION SYSTEMS FOR BIOMASS ENERGY PRODUCTION IN A CENTRAL

ABSTRACT: The environmental performance of fiber sorghum crop production systems in Umbria (Italy) was analyzed using a LCA methodology, tailored to biomass production. Two different tillage systems were compared concerning the type of irrigation: dryland conditions and traveling big-gun system. The analysis considered the entire system, which was required to produce 1 MJ of fiber sorghum energy content; it included the extraction of raw materials, like fossil fuels and minerals, the production of farming inputs, such as fertilizers and pesticides, and all agricultural operations in the field. Information about resource consumption associated to crops production was taken from a field trial in Italy (Casalina, Perugia). The LCA method used in this study aggregates all resources used and all emissions released into environment, defined into Life Cycle Inventory, in the following impact categories: depletion of abiotic resources, freshwater consumption, climate change, land use, acidification, eutrophication, human toxicity, eco-toxicity, soil erosion. Results reveals that dryland and irrigated conditions are characterized by an equivalent environmental impact mostly due to phosphate fertilizers consumption, soil erosion, nitrate emissions and, for irrigated conditions, water consumption. Tested method seemed suitable to evaluate environmental burdens of energy crops, because it only considers impact categories important for biomass production