Effect of irrigation and N fertilization on the botanical composition of mountain meadows

摘要

Because of recurrent drought events in the last fifteen years, grassland irrigation has gained relevance in the mountainous areas of the southern slopes of the Alps. Besides the beneficial effects on forage yield, the effect of the irrigation on the botanical composition of grassland represents a relevant issue for grassland management, but experimental evidence about this topic is limited. A data set describing the botanical composition of permanent meadows at the first cut at 220 environments in South Tyrol (NE Italy), encompassing a broad range of environmental conditions and management intensities, was used to explore the effect of irrigation on the most common grassland species by means of mixed models taking into account the design effects, Ninput and the occurrence of irrigation. For about one-third of the species a significant (Dactylis glomerata, Lolium perenne) or marginally significant (Poa trivialis, Rumex acetosa) effect of irrigation on their yield proportion could be ascertained. Specifically designed research is required to provide more precise information about this topic.