Water and carbon economy in sustainable orchards in Mediterranean environments

Agriculture is a key socio-economic sector and a driving force of sustainable development as it is involved in conservation of natural resources and in climate changes because it contributes to greenhouse gases (GHG) by sources as well as removals, through photosynthesis. To face increasing global population and food security agriculture should improve the water productivity. Improvement of orchard management practices aimed at increase soil fertility traits (e.g., soil organic carbon, microbial community, porosity) will be beneficial also for improvement of water use efficiency at farm scale through improved soil water holding capacity. This paper examines some effects of sustainable orchard management (Smng) practices (no-tillage, pruning residues and cover crop retention, compost application) in a Mediterranean environment, organic carbon and irrigation volumes. Comparisons were made against the conventional management (Cmng). Orchards under Smng increased the amount of carbon removed from atmosphere and stored as biomass and organic carbon into soil. Adoption of cover crops at the Smng orchard might remove 1.5-3.6 t C ha-1 year-1. Through a life-cycle assessment (LCA) approach, this paper reports that application of Smng practices is able to reduce by ∼20% the GHG emissions throughout the whole lifespan of orchards compared to Cmng. Adoption of the Smng practice was also beneficial for the reduction of the amount of irrigation water supplied which was approximately 20% lower than that of Cmng. Implications on the economic water productivity are also reported.