Effects of intensive management on the biomass composition of mountain meadows under recurrent drought.

The increasing economic pressure on grassland farming in disadvantaged areas, such as in mountain regions, has often resulted in an intensification of the favourable areas and abandonment of the labour-intensive areas. In such situations, farmers often attempt to increase forage production, allocating a larger amount of dung to the easily accessible farm plots and increasing the cutting frequency, but climatic constraints such as drought hamper plant growth. In order to investigate the effect of intensive management on the botanical composition of mountain permanent meadows under recurrent drought, a seven-year field experiment was conducted in South Tyrol. Different cutting frequencies (two to four cuts per year), coupled with increasing fertilization rates (44 to 88 m³ ha-1 yr-1 of slurry, respectively), as well as a control treatment (two cuts yr-1 ; 19.8 m³ ha-1 yr-1 of slurry), were applied. The yield share of each species was visually assessed immediately before the first cut. Depending on the treatment, a distinct vegetation dynamics was apparent after seven years. Our results show that several years of high nutrient supply, coupled to recurring drought, negatively affect the botanical composition of permanent meadows.