Resumen
Specialized agricultural systems may have a strong environmental impact, thus affecting the sustainability of production. The aim of this study is to evaluate the overall environmental impact of the hazelnut production, focusing on the main Italian production area, which is located in the province of Viterbo (central Italy). The theoretical approach adopted in this study refers to the paradigm of ecological economics, recalling the concept of strong sustainability through the conservation of natural capital and its non-replacement with economic capital. This environmental sustainability of farming systems is assessed through the ecological balance (EB) tool by comparing the availability and use of natural capital in each farm scenario. This allows to understand the extent of the load generated on the environment by the different farm?s typologies, as well as the impact on the entire territory where hazelnut cultivation is predominant. For the assessment, local typical farm scenarios are assessed through a Delphi consultation of a panel of experts, thus characterizing the cultivation techniques most frequently adopted in the area. Three typologies of representative farms emerge, which mainly differ for cultivation method and dimension. Cultivation methods associated with the larger farms (both conventional and organic) generate a positive contribution to EB, whereas small farms (conventional) have a negative EB due to the high utilization of inputs. However, the positive balance of the large farms compensates for the negative balance of the small ones. This determines a total positive environmental balance of the specialized production area of Viterbo, equal to 9412 gha. This means that hazelnut farming at a territorial level is sustainable thanks to specific farm managements, which can be promoted by policy-makers.