Strategies to transform organic residues from olive and wine industries: Greenhouse gas emissions and climate change

Presentado en el II International Symposium on Organic Matter Management and Compost Use in Horticulture, celebrado en Santiago de Chile del 21 al 24 de octubre de 2013.The agricultural recycling of olive mill and winery wastes through composting and land application is reviewed in this manuscript in terms of the impact on greenhouse gas (GHG) emissions and the potential for soil C sequestration. The rich lignocellulosic composition and the low N availability of olive mill wastes have been revealed as the driving factors of the low degradation rate of these wastes during composting and after soil application. These peculiar characteristics minimise the emission of CH4 and N2O during composting and lead to an efficient and long-term C stabilisation when applied to the soil. These findings confirm the interest of the use of olive mill wastes in agriculture as a strategy to tackle the increasing CO2 concentrations in the atmosphere, which is further supported by the well-known favourable agronomical properties of these wastes. The suitability of this strategy is also examined for winery wastes, which share some similar physicochemical characteristics with olive mill wastes. The agricultural use of these organic wastes could have important environmental benefits in Mediterranean agroecosystems.Peer reviewe