S. Boléo

Perennial Grass Production Opportunities on Marginal Mediterranean Land

An increasing global awareness that the supply and security of petroleum-based materials is diminishing, coupled with environmental concerns related to climate change, water availability, and soil degradation, has increased demand for more renewable, diversified, and sustainable agricultural production systems. The objective of this work was to determine if a biogenic approach, focused on producing perennial grasses on marginal Mediterranean land as feedstock for bioenergy or bio-based products, could reduce greenhouse gas (GHG) emissions without depleting soil nutrients, water supplies, or negatively impacting biological and landscape diversity. This study, funded by European Union (EU), was conducted under project optimization of perennial grasses for biomass production (OPTIMA) using environmental impact assessment (EIA) protocols to quantify local environmental impacts of producing perennial grasses, in the Mediterranean region. Different end uses were investigated and biogenic products were compared with conventional ones. The EIA assessment indicated that the biogenic system had low erodibility potential, reduced disturbance of soil properties, and minimal hydrological impacts. Less tillage and high biomass production supported biological and landscape diversity, but site-specific factors should be used to appropriately match the specific crop and location. We conclude that producing perennial grasses on marginal Mediterranean land is feasible and if appropriately managed will have relatively few environmental side effects.

Phytoremediation of Inorganic Compounds

Phytoremediation, the use of plants and their associated microbes for soil, water, and air decontamination, is a cost-effective, solar-driven, and alternative/complementary technology for physicochemical approaches. Plants can be used for extraction, stabilization, degradation, and volatilization as well as for the conversion of many inorganic compounds as nitrates, phosphates, metals, and radionuclides to less toxic forms, reducing their associate risks to humans, animals, and the environment. The applicability of these mechanisms is reviewed here, including its applicability for soils contaminated with heavy metals and radionuclides, as well as the application of plants for the improvement of water quality in polluted waters (phytodepuration). Main polluted sites in Europe and main polluting anthropogenic activities where identified. The main soil remediation technologies, and, in particular, the application of phytoremediation technology using industrial crops and their mechanisms with the generation of economic value was referred. The advantages and limitations of this approach are also presented. Bridging phytoremediation with the production of a multipurpose biomass could provide environmental benefits and social and economic opportunities, by improving the overall sustainability of the biosystem.