Description:
To favor transition towards sustainable agricultural systems, the agricultural sector needs to reduce its dependence on external inputs. From an ecological economics perspective, this requires the simultaneous fulfillment of a gross energy surplus on the farm (production condition), and a greater recirculation of the production extracted from the agroecosystem (reproduction condition). Using eight smallholder farms, this study focuses on the processes of recirculation and externalization of biomass, materials and energy flows in the agroecosystem. This is carried out through analyzing the MEFA (Material and Energy Flow Analysis) matrix by means of energy return on the investment indexes of inputs (EFEROI), recirculations (IFEROI), summation efficiency (EROI) and final joint efficiency (FEROI), all of which impact upon farm-scale decision-making related to cost-benefit situations. Agrarian fossilization indices are applied to include an assessment of farm non-renewable energy profiles. The results indicate a restriction of inputs in conventional farm-operators and a troubling use of indirect fossil-fuel in organic operators, together with a weakening of the agroecosystem reproductive processes by means of external inputs for both systems. We conclude that to guide the transition towards sustainable agricultural systems, farming strategies need to focus on reducing indirect fossil-fuel energy consumption, rather than relying on technological substitutions