Added value of grassland based dairy farming systems: the Trentingrana PDO production in Eastern Italian Alps.

Mountain grassland-based dairy livestock farming is associated with the provision of several positive environmental externalities, also ensuring the management of marginal pastures and supporting local tourism activities. These systems are normally characterised by a stronger link with the territory when compared to conventional ones located in plain areas, contributing to support the local economy. Therefore, specific indicators are needed to maximise the positive contributions of these systems and mitigate the negative ones. This study aims at investigating mountain grassland-based dairy farming, to develop tailored indicators to maintain its link with the territory and its positive associated externalities. Farm structure and management data were collected from 23 grassland-based dairy farms under the Trentingrana PDO cheese certification scheme, located in three mountain areas (Val di Fassa, Primiero, Val di Non) in the province of Trento (Italy). A Principal Component Analysis, conducted to select the most representative variables, identified 4 indicators: altitude, farmland area, share of permanent grasslands (PG), loose housing. These indicators were combined with farm locations data to perform a K-means clustering, obtaining 3 clusters. Additional indicators for geo-morphological and landscape features and ecosystem services were computed using the software QGIS. A one-way Anova was then performed to investigate differences between the clusters. Cluster 1 represented mid-altitude farms (961m asl), with medium surfaces (35 ha), the largest herds (75 cows), total share of loose housing, the highest milk yield (11715 kg Energy Corrected Milk – ECM – /cow/year), the lowest field slope (8.66°) and no agrotourism activity. Cluster 2 described mid-altitude (802 m asl), smallest farms (22ha and 24 cows), with farm surfaces totally managed as permanent grasslands, medium share of loose housing (50%), the lowest milk yield (8088 kg ECM/cow/year), medium field slope (10.81°) and 44% of farms with agrotourism activity. Cluster 3 referred to farms located at the highest altitude (1523 m asl), managing the widest surfaces (69 ha), with medium-sized herds (45 cows), the lowest number of cuts on PG (1.7), farm surfaces totally managed as permanent grasslands, medium share of loose housing (65%), medium milk yields (10087 kg ECM/cow/year), the highest field slope (13.64°) and 67% of farms with agrotourism activity. Clusters were similar for the other factors considered, including milk price and additional ecosystem services indicators. In conclusion, farms belonging to Cluster 1 were reasonably located in more favourable areas, adopting a higher level of intensification carried out with increased herd size and milk yields, but without diversifying their activity through agrotourism. Farms belonging to Cluster 3 were situated in less favourable areas, located at the highest altitude and with fields characterised by the highest slope, but were able to maintain high production levels, also diversifying their activity by integrating agrotourism to a certain extent. Farms grouped into Cluster 2, despite being located in favourable areas, managed the smallest surfaces and herds, obtaining the lowest production levels and still adopting a medium share of tie-stall housing, therefore maintaining a more traditional production system. The above-mentioned indicators will be integrated with impact categories (Life Cycle Assessment and nutrients excretion data) and ecosystem services indicators, to monitor the multiple relationships between dairy farming and agroecosystems in the Trentingrana PDO cheese production chain.