Sustainability of grassland-based dairy farms: a case study

Grassland-based livestock farming is linked to several positive externalities, such as landscape maintenance, carbon sequestration, local biodiversity, and cultural heritage. However, local economic and climatic constraints can lead to land and low-input farms abandonment. This contribution aims at assessing the sustainability of low-input grassland-based farming, thereby supporting its environmental and economic viability. Farm structure and management data were collected from 41 grassland-based dairy farms in the province of Salzburg (Austria). A Principal Component Analysis identified 10 indicators: altitude, organic, farmland area, field size, cuts on permanent grasslands (PG), husbandry system, herd size, milk yield (MY), outdoor access, share of PG. K-means clustering was then performed, obtaining 3 clusters. Cluster 1 represented conventional (85%), medium sized (16 ha) farms at mid altitude (507 m asl), with small PG fields (1.35 ha), medium sized herds (18 cows), tie stalls, zero concentrate self-sufficiency (CSS), and both the lowest outdoor access (61 days/year – d/y) and milk price (0.42€/l). Cluster 2 described higher altitude (741 m asl), organic, small farms (11 ha) and fields (1.4 ha), with low arable land and temporary grasslands (TG) (15%), small herds (10 cows), medium loose housing (43%) and outdoor access (155 d/y), low CSS (15%), and higher milk price (0.48€/l). Cluster 3 referred to mid altitude (544 m asl), organic (90%), largest farms (35 ha) and fields (1.84 ha), with low arable land and TG (10%), largest herds (31 cows), loose housing (100%), the highest outdoor access (301 d/y), CSS (22%), and milk price (0.5€/l). Clusters were similar for the other factors considered. In conclusion, Cluster 3 showed the highest future viability, with loose housing, the highest milk price and feed self-sufficiency, maintaining a strong link with the territory. Cluster 2 achieved good milk price and feed self-sufficiency, with higher tie stalls, and the smallest herd size, due to the higher altitude. In a long-term scenery, Cluster 1 has the lowest viability, potentially improvable through investments to enhance its durability.